response functions: Topics by Science.gov

Sample records for response functions

A predator-prey model with a holling type I functional response including a predator mutual interference

USGS Publications Warehouse

Seo, G.; DeAngelis, D.L.

2011-01-01

The most widely used functional response in describing predator-prey relationships is the Holling type II functional response, where per capita predation is a smooth, increasing, and saturating function of prey density. Beddington and DeAngelis modified the Holling type II response to include interference of predators that increases with predator density. Here we introduce a predator-interference term into a Holling type I functional response. We explain the ecological rationale for the response and note that the phase plane configuration of the predator and prey isoclines differs greatly from that of the Beddington-DeAngelis response; for example, in having three possible interior equilibria rather than one. In fact, this new functional response seems to be quite unique. We used analytical and numerical methods to show that the resulting system shows a much richer dynamical behavior than the Beddington-DeAngelis response, or other typically used functional responses. For example, cyclic-fold, saddle-fold, homoclinic saddle connection, and multiple crossing bifurcations can all occur. We then use a smooth approximation to the Holling type I functional response with predator mutual interference to show that these dynamical properties do not result from the lack of smoothness, but rather from subtle differences in the functional responses. ?? 2011 Springer Science+Business Media, LLC.
Exotic species enhance response diversity to land-use change but modify functional composition.

PubMed

Stavert, Jamie R; Pattemore, David E; Gaskett, Anne C; Beggs, Jacqueline R; Bartomeus, Ignasi

2017-08-16

Two main mechanisms may buffer ecosystem functions despite biodiversity loss. First, multiple species could share similar ecological roles, thus providing functional redundancy. Second, species may respond differently to environmental change (response diversity). However, ecosystem function would be best protected when functionally redundant species also show response diversity. This linkage has not been studied directly, so we investigated whether native and exotic pollinator species with similar traits (functional redundancy) differed in abundance (response diversity) across an agricultural intensification gradient. Exotic pollinator species contributed most positive responses, which partially stabilized overall abundance of the pollinator community. However, although some functionally redundant species exhibited response diversity, this was not consistent across functional groups and aggregate abundances within each functional group were rarely stabilized. This shows functional redundancy and response diversity do not always operate in concert. Hence, despite exotic species becoming increasingly dominant in human-modified systems, they cannot replace the functional composition of native species. © 2017 The Author(s).
Use of selection indices to model the functional response of predators

USGS Publications Warehouse

Joly, D.O.; Patterson, B.R.

2003-01-01

The functional response of a predator to changing prey density is an important determinant of stability of predatora??prey systems. We show how Manly's selection indices can be used to distinguish between hyperbolic and sigmoidal models of a predator functional response to primary prey density in the presence of alternative prey. Specifically, an inverse relationship between prey density and preference for that prey results in a hyperbolic functional response while a positive relationship can yield either a hyperbolic or sigmoidal functional response, depending on the form and relative magnitudes of the density-dependent preference model, attack rate, and handling time. As an example, we examine wolf (Canis lupus) functional response to moose (Alces alces) density in the presence of caribou (Rangifer tarandus). The use of selection indices to evaluate the form of the functional response has significant advantages over previous attempts to fit Holling's functional response curves to killing-rate data directly, including increased sensitivity, use of relatively easily collected data, and consideration of other explanatory factors (e.g., weather, seasons, productivity).
Local and linear chemical reactivity response functions at finite temperature in density functional theory

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

Franco-Pérez, Marco, E-mail: francopj@mcmaster.ca, E-mail: ayers@mcmaster.ca, E-mail: jlgm@xanum.uam.mx, E-mail: avela@cinvestav.mx; Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, México, D.F. 09340; Ayers, Paul W., E-mail: francopj@mcmaster.ca, E-mail: ayers@mcmaster.ca, E-mail: jlgm@xanum.uam.mx, E-mail: avela@cinvestav.mx

2015-12-28

We explore the local and nonlocal response functions of the grand canonical potential density functional at nonzero temperature. In analogy to the zero-temperature treatment, local (e.g., the average electron density and the local softness) and nonlocal (e.g., the softness kernel) intrinsic response functions are defined as partial derivatives of the grand canonical potential with respect to its thermodynamic variables (i.e., the chemical potential of the electron reservoir and the external potential generated by the atomic nuclei). To define the local and nonlocal response functions of the electron density (e.g., the Fukui function, the linear density response function, and the dualmore » descriptor), we differentiate with respect to the average electron number and the external potential. The well-known mathematical relationships between the intrinsic response functions and the electron-density responses are generalized to nonzero temperature, and we prove that in the zero-temperature limit, our results recover well-known identities from the density functional theory of chemical reactivity. Specific working equations and numerical results are provided for the 3-state ensemble model.« less
Local and linear chemical reactivity response functions at finite temperature in density functional theory.

PubMed

Franco-Pérez, Marco; Ayers, Paul W; Gázquez, José L; Vela, Alberto

2015-12-28

We explore the local and nonlocal response functions of the grand canonical potential density functional at nonzero temperature. In analogy to the zero-temperature treatment, local (e.g., the average electron density and the local softness) and nonlocal (e.g., the softness kernel) intrinsic response functions are defined as partial derivatives of the grand canonical potential with respect to its thermodynamic variables (i.e., the chemical potential of the electron reservoir and the external potential generated by the atomic nuclei). To define the local and nonlocal response functions of the electron density (e.g., the Fukui function, the linear density response function, and the dual descriptor), we differentiate with respect to the average electron number and the external potential. The well-known mathematical relationships between the intrinsic response functions and the electron-density responses are generalized to nonzero temperature, and we prove that in the zero-temperature limit, our results recover well-known identities from the density functional theory of chemical reactivity. Specific working equations and numerical results are provided for the 3-state ensemble model.
Local representation of the electronic dielectric response function

DOE PAGES

Lu, Deyu; Ge, Xiaochuan

2015-12-11

We present a local representation of the electronic dielectric response function, based on a spatial partition of the dielectric response into contributions from each occupied Wannier orbital using a generalized density functional perturbation theory. This procedure is fully ab initio, and therefore allows us to rigorously define local metrics, such as “bond polarizability,” on Wannier centers. We show that the locality of the bare response function is determined by the locality of three quantities: Wannier functions of the occupied manifold, the density matrix, and the Hamiltonian matrix. Furthermore, in systems with a gap, the bare dielectric response is exponentially localized,more » which supports the physical picture of the dielectric response function as a collection of interacting local responses that can be captured by a tight-binding model.« less
Linear and quadratic static response functions and structure functions in Yukawa liquids.

PubMed

Magyar, Péter; Donkó, Zoltán; Kalman, Gabor J; Golden, Kenneth I

2014-08-01

We compute linear and quadratic static density response functions of three-dimensional Yukawa liquids by applying an external perturbation potential in molecular dynamics simulations. The response functions are also obtained from the equilibrium fluctuations (static structure factors) in the system via the fluctuation-dissipation theorems. The good agreement of the quadratic response functions, obtained in the two different ways, confirms the quadratic fluctuation-dissipation theorem. We also find that the three-point structure function may be factorizable into two-point structure functions, leading to a cluster representation of the equilibrium triplet correlation function.
20 CFR 404.1546 - Responsibility for assessing your residual functional capacity.

Code of Federal Regulations, 2011 CFR

2011-04-01

... functional capacity. 404.1546 Section 404.1546 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD... Functional Capacity § 404.1546 Responsibility for assessing your residual functional capacity. (a) Responsibility for assessing residual functional capacity at the State agency. When a State agency medical or...
Analyzing the Stability of Price Response Functions: Measuring the Influence of Different Parameters in a Monte Carlo Comparison

NASA Astrophysics Data System (ADS)

Brusch, Michael; Baier, Daniel

The usage and the estimation of price response function is very important for strategic marketing decisions. Typically price response functions with an empirical basis are used. However, such price response functions are subject to a lot of disturbing influence factors, e.g., the assumed profit maximum price and the assumed corresponding quantity of sales. In such cases, the question how stable the found price response function is was not answered sufficiently up to now. In this paper, the question will be pursued how much (and what kind of) errors in market research are pardonable for a stable price response function. For the comparisons, a factorial design with synthetically generated and disturbed data is used.
Biologically plausible particulate air pollution mortality concentration-response functions.

PubMed Central

Roberts, Steven

2004-01-01

In this article I introduce an alternative method for estimating particulate air pollution mortality concentration-response functions. This method constrains the particulate air pollution mortality concentration-response function to be biologically plausible--that is, a non-decreasing function of the particulate air pollution concentration. Using time-series data from Cook County, Illinois, the proposed method yields more meaningful particulate air pollution mortality concentration-response function estimates with an increase in statistical accuracy. PMID:14998745
Trajectories of positive, negative and general psychopathology symptoms in first episode psychosis and their relationship with functioning over a 2-year follow-up period.

PubMed

Abdin, Edimansyah; Chong, Siow Ann; Vaingankar, Janhavi Ajit; Peh, Chao Xu; Poon, Lye Yin; Rao, Sujatha; Verma, Swapna; Subramaniam, Mythily

2017-01-01

Few studies have examined the trajectories of symptom severity in first episode psychosis (FEP) and their impact on functioning. This study aimed to identify discrete trajectories of positive, negative and general psychopathological symptoms and functioning, determine predictors of the identified symptom trajectories and subsequently investigate the relationship between symptom and functioning trajectories over the 2-year follow-up period. Data were extracted from the Singapore Early Psychosis Intervention Programme clinical database. Trajectories of the Positive and Negative Syndrome Scale and Global Assessment of Functioning (GAF) scale over the two-year follow up were modelled using latent class growth curve modelling. Two distinct trajectories (early response and stable trajectory and delayed response trajectory) for positive symptoms, four distinct trajectories (early response and stable trajectory, early response and relapse trajectory, slower response and no response trajectory and delayed response trajectory) for negative and general psychopathology symptoms and three distinct trajectories for functioning (high functioning trajectory, moderately stable functioning trajectory and deterioration in functioning trajectory) were identified in our sample. Compared to individuals in the early response and stable trajectory, those in the delayed response trajectory for positive and negative symptoms, early response and relapse for negative and general psychopathology symptoms and slower response and no response trajectories for general psychopathology symptoms were significantly associated with higher odds of having deterioration in functioning over time. Poor symptom trajectories were also significantly predicted by younger age, male gender, unemployed and economically inactive status, lower education, longer duration of untreated psychosis and diagnosis of schizophrenia spectrum and delusional disorders. The results confirm that the symptoms trajectories among patients with FEP are heterogeneous and suggest that a small group of patients may be at higher risk of deterioration in symptom severity and functioning over the 2-year follow-up.
The numerical and functional responses of a granivorous rodent and the fate of Neotropical tree seeds

USGS Publications Warehouse

Klinger, R.; Rejmanek, M.

2009-01-01

Despite their potential to provide mechanistic explanations of rates of seed dispersal and seed fate, the functional and numerical responses of seed predators have never been explicitly examined within this context. Therefore, we investigated the numerical response of a small-mammal seed predator, Heteromys desmarestianus, to disturbance-induced changes in food availability and evaluated the degree to which removal and fate of seeds of eight tree species in a lowland tropical forest in Belize were related to the functional response of H. desmarestianus to varying seed densities. Mark-recapture trapping was used to estimate abundance of H. desmarestianus in six 0.5-ha grids from July 2000 to September 2002. Fruit availability and seed fate were estimated in each grid, and two experiments nested within the grids were used to determine (1) the form of the functional response for nine levels of fruit density (2-32 fruits/m 2), (2) the removal rate and handling times, and (3) the total proportion of fruits removed. The total proportion of fruits removed was determined primarily by the numerical response of H. desmarestianus to fruit availability, while removal rates and the proportion of seeds eaten or cached were related primarily to the form of the functional response. However, the numerical and functional responses interacted; H. desmarestianus showed strong spatial and temporal numerical responses to total fruit availability, and their density relative to fruit availability resulted in variation in the form of the functional response. Types I, II, and III functional responses were observed, as were density-independent responses, and these responses varied both among and within fruit species. The highest proportions of fruits were eaten when the Type III functional response was detected, which was when fruit availability was high relative to H. desmarestianus population density. Numerous idiosyncratic influences on seed fate have been documented, but our results indicate that shifts in the numerical and functional responses of seed predators to seasonal and interannual variation in seed availability potentially provide a general mechanistic explanation for patterns of removal and fate for vertebrate-dispersed seeds. ?? 2009 by the Ecological Society of America.
20 CFR 416.946 - Responsibility for assessing your residual functional capacity.

Code of Federal Regulations, 2011 CFR

2011-04-01

... functional capacity. 416.946 Section 416.946 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL... Capacity § 416.946 Responsibility for assessing your residual functional capacity. (a) Responsibility for assessing residual functional capacity at the State agency. When a State agency medical or psychological...
Detector response function of an energy-resolved CdTe single photon counting detector.

PubMed

Liu, Xin; Lee, Hyoung Koo

2014-01-01

While spectral CT using single photon counting detector has shown a number of advantages in diagnostic imaging, knowledge of the detector response function of an energy-resolved detector is needed to correct the signal bias and reconstruct the image more accurately. The objective of this paper is to study the photo counting detector response function using laboratory sources, and investigate the signal bias correction method. Our approach is to model the detector response function over the entire diagnostic energy range (20 keV
Modification of response functions of cat visual cortical cells by spatially congruent perturbing stimuli.

PubMed

Kabara, J F; Bonds, A B

2001-12-01

Responses of cat striate cortical cells to a drifting sinusoidal grating were modified by the superimposition of a second, perturbing grating (PG) that did not excite the cell when presented alone. One consequence of the presence of a PG was a shift in the tuning curves. The orientation tuning of all 41 cells exposed to a PG and the spatial frequency tuning of 83% of the 23 cells exposed to a PG showed statistically significant dislocations of both the response function peak and center of mass from their single grating values. As found in earlier reports, the presence of PGs suppressed responsiveness. However, reductions measured at the single grating optimum orientation or spatial frequency were on average 1.3 times greater than the suppression found at the peak of the response function modified by the presence of the PG. Much of the loss in response seen at the single grating optimum is thus a result of a shift in the tuning function rather than outright suppression. On average orientation shifts were repulsive and proportional (approximately 0.10 deg/deg) to the angle between the perturbing stimulus and the optimum single grating orientation. Shifts in the spatial frequency response function were both attractive and repulsive, resulting in an overall average of zero. For both simple and complex cells, PGs generally broadened orientation response function bandwidths. Similarly, complex cell spatial frequency response function bandwidths broadened. Simple cell spatial frequency response functions usually did not change, and those that did broadened only 4% on average. These data support the hypothesis that additional sinusoidal components in compound stimuli retune cells' response functions for orientation and spatial frequency.
Structural frequency functions for an impulsive, distributed forcing function

NASA Technical Reports Server (NTRS)

Bateman, Vesta I.

1987-01-01

The response of a penetrator structure to a spatially distributed mechanical impulse with a magnitude approaching field test force levels (1-2 Mlb) were measured. The frequency response function calculated from the response to this unique forcing function is compared to frequency response functions calculated from response to point forces of about 2000 pounds. The results show that the strain gages installed on the penetrator case respond similiarly to a point, axial force and to a spatially distributed, axial force. This result suggests that the distributed axial force generated in a penetration event may be reconstructed as a point axial force when the penetrator behaves in linear manner.
Response function of modulated grid Faraday cup plasma instruments

NASA Technical Reports Server (NTRS)

Barnett, A.; Olbert, S.

1986-01-01

Modulated grid Faraday cup plasma analyzers are a very useful tool for making in situ measurements of space plasmas. One of their great attributes is that their simplicity permits their angular response function to be calculated theoretically. An expression is derived for this response function by computing the trajectories of the charged particles inside the cup. The Voyager plasma science experiment is used as a specific example. Two approximations to the rigorous response function useful for data analysis are discussed. Multisensor analysis of solar wind data indicates that the formulas represent the true cup response function for all angles of incidence with a maximum error of only a few percent.
On the subsystem formulation of linear-response time-dependent DFT.

PubMed

Pavanello, Michele

2013-05-28

A new and thorough derivation of linear-response subsystem time-dependent density functional theory (TD-DFT) is presented and analyzed in detail. Two equivalent derivations are presented and naturally yield self-consistent subsystem TD-DFT equations. One reduces to the subsystem TD-DFT formalism of Neugebauer [J. Chem. Phys. 126, 134116 (2007)]. The other yields Dyson type equations involving three types of subsystem response functions: coupled, uncoupled, and Kohn-Sham. The Dyson type equations for subsystem TD-DFT are derived here for the first time. The response function formalism reveals previously hidden qualities and complications of subsystem TD-DFT compared with the regular TD-DFT of the supersystem. For example, analysis of the pole structure of the subsystem response functions shows that each function contains information about the electronic spectrum of the entire supersystem. In addition, comparison of the subsystem and supersystem response functions shows that, while the correlated response is subsystem additive, the Kohn-Sham response is not. Comparison with the non-subjective partition DFT theory shows that this non-additivity is largely an artifact introduced by the subjective nature of the density partitioning in subsystem DFT.
Energy Response Function of CALET Gamma Ray Burst Monitor

NASA Astrophysics Data System (ADS)

Yamada, Y.; Sakamoto, T.; Yoshida, A.; Calet Collaboration

2016-10-01

We will explain the development of the CGBM energy response function. We will also show the spectral analysis results of CGBM using our developed energy response function for simultaneously detected bright GRBs by other GRB detectors.
Decreased prefrontal functional brain response during memory testing in women with Cushing's syndrome in remission.

PubMed

Ragnarsson, Oskar; Stomby, Andreas; Dahlqvist, Per; Evang, Johan A; Ryberg, Mats; Olsson, Tommy; Bollerslev, Jens; Nyberg, Lars; Johannsson, Gudmundur

2017-08-01

Neurocognitive dysfunction is an important feature of Cushing's syndrome (CS). Our hypothesis was that patients with CS in remission have decreased functional brain responses in the prefrontal cortex and hippocampus during memory testing. In this cross-sectional study we included 19 women previously treated for CS and 19 controls matched for age, gender, and education. The median remission time was 7 (IQR 6-10) years. Brain activity was studied with functional magnetic resonance imaging during episodic- and working-memory tasks. The primary regions of interest were the prefrontal cortex and the hippocampus. A voxel-wise comparison of functional brain responses in patients and controls was performed. During episodic-memory encoding, patients displayed lower functional brain responses in the left and right prefrontal gyrus (p<0.001) and in the right inferior occipital gyrus (p<0.001) compared with controls. There was a trend towards lower functional brain responses in the left posterior hippocampus in patients (p=0.05). During episodic-memory retrieval, the patients displayed lower functional brain responses in several brain areas with the most predominant difference in the right prefrontal cortex (p<0.001). During the working memory task, patients had lower response in the prefrontal cortices bilaterally (p<0.005). Patients, but not controls, had lower functional brain response during a more complex working memory task compared with a simpler one. In conclusion, women with CS in long-term remission have reduced functional brain responses during episodic and working memory testing. This observation extends previous findings showing long-term adverse effects of severe hypercortisolaemia on brain function. Copyright © 2017 Elsevier Ltd. All rights reserved.

Customized acoustic transform functions and their accuracy at predicting real-ear hearing aid performance.

PubMed

Munro, K J; Hatton, N

2000-02-01

The purpose of the study was to evaluate the validity of predicting the real-ear aided response by adding customized acoustic transform functions to the performance of a hearing aid in a 2-cc coupler. The real-ear hearing aid response, the real-ear-to-coupler difference (RECD/HA2), and field to behind-the-ear microphone transfer functions were measured in both ears of 24 normally hearing subjects using probe-tube microphone equipment. The RECD/HA2 transform function was obtained using both insert earphones and with the hearing aid/ pressure comparison method. An RECD/HA2 transfer function was also obtained with a customized earmold, ER-3A foam tip, and an oto-admittance tip. Validity estimates were calculated as the difference between the derived and measured real-ear response. The derived response was generally within 5 dB of the measured real-ear response when it incorporated an RECD/HA2 transform function obtained with a customized earmold for the specific ear in question. Discrepancies increased when the RECD/HA2 transfer function was obtained from the same subject but the opposite ear. There were significant differences between the RECD/HA2 transform function obtained with customized and temporary earmolds. As a result, the derived response incorporating these transforms differed significantly from the measured real-ear response obtained with the customized earmold. The insert earphone and the hearing aid RECD/HA2 transfer function were equally valid. The derived response may be used as a substitute for in situ hearing aid response procedures when it incorporates acoustic transform functions obtained with a customized earmold from the specific ear in question.
Exchange Energy Density Functionals that reproduce the Linear Response Function of the Free Electron Gas

NASA Astrophysics Data System (ADS)

García-Aldea, David; Alvarellos, J. E.

2009-03-01

We present several nonlocal exchange energy density functionals that reproduce the linear response function of the free electron gas. These nonlocal functionals are constructed following a similar procedure used previously for nonlocal kinetic energy density functionals by Chac'on-Alvarellos-Tarazona, Garc'ia-Gonz'alez et al., Wang-Govind-Carter and Garc'ia-Aldea-Alvarellos. The exchange response function is not known but we have used the approximate response function developed by Utsumi and Ichimaru, even we must remark that the same ansatz can be used to reproduce any other response function with the same scaling properties. We have developed two families of new nonlocal functionals: one is constructed with a mathematical structure based on the LDA approximation -- the Dirac functional for the exchange - and for the second one the structure of the second order gradient expansion approximation is took as a model. The functionals are constructed is such a way that they can be used in localized systems (using real space calculations) and in extended systems (using the momentum space, and achieving a quasilinear scaling with the system size if a constant reference electron density is defined).
Edge analyzing properties of center/surround response functions in cybernetic vision

NASA Technical Reports Server (NTRS)

Jobson, D. J.

1984-01-01

The ability of center/surround response functions to make explicit high resolution spatial information in optical images was investigated by performing convolutions of two dimensional response functions and image intensity functions (mainly edges). The center/surround function was found to have the unique property of separating edge contrast from shape variations and of providing a direct basis for determining contrast and subsequently shape of edges in images. Computationally simple measures of contrast and shape were constructed for potential use in cybernetic vision systems. For one class of response functions these measures were found to be reasonably resilient for a range of scan direction and displacements of the response functions relative to shaped edges. A pathological range of scan directions was also defined and methods for detecting and handling these cases were developed. The relationship of these results to biological vision is discussed speculatively.
Response functions of free mass gravitational wave antennas

NASA Technical Reports Server (NTRS)

Estabrook, F. B.

1985-01-01

The work of Gursel, Linsay, Spero, Saulson, Whitcomb and Weiss (1984) on the response of a free-mass interferometric antenna is extended. Starting from first principles, the earlier work derived the response of a 2-arm gravitational wave antenna to plane polarized gravitational waves. Equivalent formulas (generalized slightly to allow for arbitrary elliptical polarization) are obtained by a simple differencing of the '3-pulse' Doppler response functions of two 1-arm antennas. A '4-pulse' response function is found, with quite complicated angular dependences for arbitrary incident polarization. The differencing method can as readily be used to write exact response functions ('3n+1 pulse') for antennas having multiple passes or more arms.
First passage time: Connecting random walks to functional responses in heterogeneous environments (Invited)

NASA Astrophysics Data System (ADS)

Lewis, M. A.; McKenzie, H.; Merrill, E.

2010-12-01

In this talk I will outline first passage time analysis for animals undertaking complex movement patterns, and will demonstrate how first passage time can be used to derive functional responses in predator prey systems. The result is a new approach to understanding type III functional responses based on a random walk model. I will extend the analysis to heterogeneous environments to assess the effects of linear features on functional responses in wolves and elk using GPS tracking data.
The response function of modulated grid Faraday cup plasma instruments

NASA Technical Reports Server (NTRS)

Barnett, A.; Olbert, S.

1986-01-01

Modulated grid Faraday cup plasma analyzers are a very useful tool for making in situ measurements of space plasmas. One of their great attributes is that their simplicity permits their angular response function to be calculated theoretically. An expression is derived for this response function by computing the trajectories of the charged particles inside the cup. The Voyager Plasma Science (PLS) experiment is used as a specific example. Two approximations to the rigorous response function useful for data analysis are discussed. The theoretical formulas were tested by multi-sensor analysis of solar wind data. The tests indicate that the formulas represent the true cup response function for all angles of incidence with a maximum error of only a few percent.
Dissociations between behavioural and functional magnetic resonance imaging-based evaluations of cognitive function after brain injury

PubMed Central

Bardin, Jonathan C.; Fins, Joseph J.; Katz, Douglas I.; Hersh, Jennifer; Heier, Linda A.; Tabelow, Karsten; Dyke, Jonathan P.; Ballon, Douglas J.; Schiff, Nicholas D.

2011-01-01

Functional neuroimaging methods hold promise for the identification of cognitive function and communication capacity in some severely brain-injured patients who may not retain sufficient motor function to demonstrate their abilities. We studied seven severely brain-injured patients and a control group of 14 subjects using a novel hierarchical functional magnetic resonance imaging assessment utilizing mental imagery responses. Whereas the control group showed consistent and accurate (for communication) blood-oxygen-level-dependent responses without exception, the brain-injured subjects showed a wide variation in the correlation of blood-oxygen-level-dependent responses and overt behavioural responses. Specifically, the brain-injured subjects dissociated bedside and functional magnetic resonance imaging-based command following and communication capabilities. These observations reveal significant challenges in developing validated functional magnetic resonance imaging-based methods for clinical use and raise interesting questions about underlying brain function assayed using these methods in brain-injured subjects. PMID:21354974
Global Developmental Change in Processing Time.

ERIC Educational Resources Information Center

Kail, Robert; Park, Young-shin

1992-01-01

Three experiments focused on the function relating children's response time to adults' response time in corresponding conditions. In all experiments, children's response times increased in a linear manner as a function of adults' response times. (BB)
Comparison of dose response functions for EBT3 model GafChromic™ film dosimetry system.

PubMed

Aldelaijan, Saad; Devic, Slobodan

2018-05-01

Different dose response functions of EBT3 model GafChromic™ film dosimetry system have been compared in terms of sensitivity as well as uncertainty vs. error analysis. We also made an assessment of the necessity of scanning film pieces before and after irradiation. Pieces of EBT3 film model were irradiated to different dose values in Solid Water (SW) phantom. Based on images scanned in both reflection and transmission mode before and after irradiation, twelve different response functions were calculated. For every response function, a reference radiochromic film dosimetry system was established by generating calibration curve and by performing the error vs. uncertainty analysis. Response functions using pixel values from the green channel demonstrated the highest sensitivity in both transmission and reflection mode. All functions were successfully fitted with rational functional form, and provided an overall one-sigma uncertainty of better than 2% for doses above 2 Gy. Use of pre-scanned images to calculate response functions resulted in negligible improvement in dose measurement accuracy. Although reflection scanning mode provides higher sensitivity and could lead to a more widespread use of radiochromic film dosimetry, it has fairly limited dose range and slightly increased uncertainty when compared to transmission scan based response functions. Double-scanning technique, either in transmission or reflection mode, shows negligible improvement in dose accuracy as well as a negligible increase in dose uncertainty. Normalized pixel value of the images scanned in transmission mode shows linear response in a dose range of up to 11 Gy. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.
Physiological stress responses predict sexual functioning and satisfaction differently in women who have and have not been sexually abused in childhood

PubMed Central

Meston, Cindy M.; Lorenz, Tierney A.

2012-01-01

Physiological responses to sexual stimuli may contribute to the increased rate of sexual problems seen in women with childhood sexual abuse (CSA) histories. We compared two physiological stress responses as predictors of sexual function and satisfaction, sympathetic nervous system (SNS) activation and cortisol in women with (CSA, N = 136) and without CSA histories (NSA, N = 102). In CSA survivors, cortisol response to sexual stimuli did not significantly predict sexual functioning; however, in NSA women, cortisol increases were associated with poorer sexual functioning, and decreases with higher functioning. For women with CSA histories, lower SNS activity was associated with poorer sexual functioning. For CSA survivors with low lifetime trauma, lower SNS activity was associated with higher sexual satisfaction; for women with high lifetime trauma, the reverse was true. Decreased SNS activity during sexual stimuli predicted higher sexual functioning in NSA women with low lifetime exposure to traumatic events, but lower sexual functioning in those with high exposure. Differences between women with and without CSA histories in the association between cortisol and SNS response and sexual functioning and satisfaction suggests that CSA causes disruptions in both short and long-term stress responses to sexual stimuli that perpetuate into adulthood. PMID:24748915
FRONTO-STRIATAL FUNCTIONAL CONNECTIVITY DURING RESPONSE INHIBITION IN ALCOHOL DEPENDENCE

PubMed Central

Courtney, Kelly E.; Ghahremani, Dara G.; Ray, Lara A.

2013-01-01

Poor response inhibition has been implicated in the development of alcohol dependence, yet little is known about how neural pathways underlying cognitive control are affected in this disorder. Moreover, endogenous opioid levels may impact the functionality of inhibitory control pathways. This study investigated the relationship between alcohol dependence severity and functional connectivity of fronto-striatal networks during response inhibition in an alcohol dependent sample. A secondary aim of this study was to test the moderating effect of a functional polymorphism (A118G) of the µ-opioid receptor (OPRM1) gene. Twenty individuals with alcohol dependence (6 females; 90% Caucasian; mean age = 29.4) who were prospectively genotyped on the OPRM1 gene underwent blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) while performing a Stop Signal Task (SST). The relationship between alcohol dependence severity and functional connectivity within fronto-striatal networks important for response inhibition was assessed using psychophysiological interaction (PPI) analyses. Analyses revealed greater alcohol dependence severity associated with weaker functional connectivity between the putamen and prefrontal regions (e.g., the anterior insula, anterior cingulate, and medial prefrontal cortex) during response inhibition. Further, the OPRM1 genotype was associated with differential response inhibition-related functional connectivity. This study demonstrates that individuals with more severe alcohol dependence exhibit less frontal connectivity with the striatum, a component of cognitive control networks important for response inhibition. These findings suggest that the fronto-striatal pathway underlying response inhibition is weakened as alcoholism progresses. PMID:23240858
A method for decoding the neurophysiological spike-response transform.

PubMed

Stern, Estee; García-Crescioni, Keyla; Miller, Mark W; Peskin, Charles S; Brezina, Vladimir

2009-11-15

Many physiological responses elicited by neuronal spikes-intracellular calcium transients, synaptic potentials, muscle contractions-are built up of discrete, elementary responses to each spike. However, the spikes occur in trains of arbitrary temporal complexity, and each elementary response not only sums with previous ones, but can itself be modified by the previous history of the activity. A basic goal in system identification is to characterize the spike-response transform in terms of a small number of functions-the elementary response kernel and additional kernels or functions that describe the dependence on previous history-that will predict the response to any arbitrary spike train. Here we do this by developing further and generalizing the "synaptic decoding" approach of Sen et al. (1996). Given the spike times in a train and the observed overall response, we use least-squares minimization to construct the best estimated response and at the same time best estimates of the elementary response kernel and the other functions that characterize the spike-response transform. We avoid the need for any specific initial assumptions about these functions by using techniques of mathematical analysis and linear algebra that allow us to solve simultaneously for all of the numerical function values treated as independent parameters. The functions are such that they may be interpreted mechanistically. We examine the performance of the method as applied to synthetic data. We then use the method to decode real synaptic and muscle contraction transforms.
Does Older Adults' Cognitive Function Disrupt the Malleability of Their Attitudes toward Outgroup Members?: An fMRI Investigation.

PubMed

Krendl, Anne C; Kensinger, Elizabeth A

2016-01-01

In the current study we examine how individual differences in older adults' global cognitive function impacts the extent to which their attitudes toward stigmatized individuals are malleable. Because prior research has elucidated the neural processes that are involved in evaluating stigmatized individuals who are responsible or not responsible for their condition, a cognitive neuroscience approach may be well-suited to answer this question. In the current study, 36 older and 17 young adults underwent functional magnetic resonance imaging while evaluating images of homeless people who were described as being responsible or not responsible for their condition. They also indicated how much pity they felt for each of the individuals in order to determine the extent to which their attitudes were malleable (e.g., more pity for not-responsible as compared to responsible individuals). Participants' cognitive function and baseline measure of their attitudes toward stigmatized individuals (including homeless individuals) were assessed. Results revealed that although older adults' attitudes were malleable, the extent to which this was true varied due to individual differences in their global cognitive function. Specifically, the difference in the magnitude of older adults' self-reported pity for not-responsible as compared to responsible homeless individuals was predicted by their global cognitive function. Moreover, the difference in pity that older adults expressed toward not-responsible as compared to responsible homeless individuals was related to activity in the left insula and the anterior cingulate cortex (regions implicated in empathy). These results suggest that attitude malleability is affected by individual differences in global cognitive function.
Does Older Adults’ Cognitive Function Disrupt the Malleability of Their Attitudes toward Outgroup Members?: An fMRI Investigation

PubMed Central

Krendl, Anne C.; Kensinger, Elizabeth A.

2016-01-01

In the current study we examine how individual differences in older adults’ global cognitive function impacts the extent to which their attitudes toward stigmatized individuals are malleable. Because prior research has elucidated the neural processes that are involved in evaluating stigmatized individuals who are responsible or not responsible for their condition, a cognitive neuroscience approach may be well-suited to answer this question. In the current study, 36 older and 17 young adults underwent functional magnetic resonance imaging while evaluating images of homeless people who were described as being responsible or not responsible for their condition. They also indicated how much pity they felt for each of the individuals in order to determine the extent to which their attitudes were malleable (e.g., more pity for not-responsible as compared to responsible individuals). Participants’ cognitive function and baseline measure of their attitudes toward stigmatized individuals (including homeless individuals) were assessed. Results revealed that although older adults’ attitudes were malleable, the extent to which this was true varied due to individual differences in their global cognitive function. Specifically, the difference in the magnitude of older adults’ self-reported pity for not-responsible as compared to responsible homeless individuals was predicted by their global cognitive function. Moreover, the difference in pity that older adults expressed toward not-responsible as compared to responsible homeless individuals was related to activity in the left insula and the anterior cingulate cortex (regions implicated in empathy). These results suggest that attitude malleability is affected by individual differences in global cognitive function. PMID:27074046
Predicting ecosystem vulnerability to biodiversity loss from community composition.

PubMed

Heilpern, Sebastian A; Weeks, Brian C; Naeem, Shahid

2018-05-01

Ecosystems vary widely in their responses to biodiversity change, with some losing function dramatically while others are highly resilient. However, generalizations about how species- and community-level properties determine these divergent ecosystem responses have been elusive because potential sources of variation (e.g., trophic structure, compensation, functional trait diversity) are rarely evaluated in conjunction. Ecosystem vulnerability, or the likely change in ecosystem function following biodiversity change, is influenced by two types of species traits: response traits that determine species' individual sensitivities to environmental change, and effect traits that determine a species' contribution to ecosystem function. Here we extend the response-effect trait framework to quantify ecosystem vulnerability and show how trophic structure, within-trait variance, and among-trait covariance affect ecosystem vulnerability by linking extinction order and functional compensation. Using in silico trait-based simulations we found that ecosystem vulnerability increased when response and effect traits positively covaried, but this increase was attenuated by decreasing trait variance. Contrary to expectations, in these communities, both functional diversity and trophic structure increased ecosystem vulnerability. In contrast, ecosystem functions were resilient when response and effect traits covaried negatively, and variance had a positive effect on resiliency. Our results suggest that although biodiversity loss is often associated with decreases in ecosystem functions, such effects are conditional on trophic structure, and the variation within and covariation among response and effect traits. Taken together, these three factors can predict when ecosystems are poised to lose or gain function with ongoing biodiversity change. © 2018 by the Ecological Society of America.
Broadband Structural Dynamics: Understanding the Impulse-Response of Structures Across Multiple Length and Time Scales

DTIC Science & Technology

2010-08-18

Spectral domain response calculated • Time domain response obtained through inverse transform Approach 4: WASABI Wavelet Analysis of Structural Anomalies...differences at unity scale! Time Function Transform Apply Spectral Domain Transfer Function Time Function Inverse Transform Transform Transform  mtP
Simulation-based Bayesian inference for latent traits of item response models: Introduction to the ltbayes package for R.

PubMed

Johnson, Timothy R; Kuhn, Kristine M

2015-12-01

This paper introduces the ltbayes package for R. This package includes a suite of functions for investigating the posterior distribution of latent traits of item response models. These include functions for simulating realizations from the posterior distribution, profiling the posterior density or likelihood function, calculation of posterior modes or means, Fisher information functions and observed information, and profile likelihood confidence intervals. Inferences can be based on individual response patterns or sets of response patterns such as sum scores. Functions are included for several common binary and polytomous item response models, but the package can also be used with user-specified models. This paper introduces some background and motivation for the package, and includes several detailed examples of its use.
Dynamic Structure Factor: An Introduction

NASA Astrophysics Data System (ADS)

Sturm, K.

1993-02-01

The doubly differential cross-section for weak inelastic scattering of waves or particles by manybody systems is derived in Born approximation and expressed in terms of the dynamic structure factor according to van Hove. The application of this very general scheme to scattering of neutrons, x-rays and high-energy electrons is discussed briefly. The dynamic structure factor, which is the space and time Fourier transform of the density-density correlation function, is a property of the many-body system independent of the external probe and carries information on the excitation spectrum of the system. The relation of the electronic structure factor to the density-density response function defined in linear-response theory is shown using the fluctuation-dissipation theorem. This is important for calculations, since the response function can be calculated approximately from the independent-particle response function in self-consistent field approximations, such as the random-phase approximation or the local-density approximation of the density functional theory. Since the density-density response function also determines the dielectric function, the dynamic structure can be expressed by the dielectric function.
Silicon Drift Detector response function for PIXE spectra fitting

NASA Astrophysics Data System (ADS)

Calzolai, G.; Tapinassi, S.; Chiari, M.; Giannoni, M.; Nava, S.; Pazzi, G.; Lucarelli, F.

2018-02-01

The correct determination of the X-ray peak areas in PIXE spectra by fitting with a computer program depends crucially on accurate parameterization of the detector peak response function. In the Guelph PIXE software package, GUPIXWin, one of the most used PIXE spectra analysis code, the response of a semiconductor detector to monochromatic X-ray radiation is described by a linear combination of several analytical functions: a Gaussian profile for the X-ray line itself, and additional tail contributions (exponential tails and step functions) on the low-energy side of the X-ray line to describe incomplete charge collection effects. The literature on the spectral response of silicon X-ray detectors for PIXE applications is rather scarce, in particular data for Silicon Drift Detectors (SDD) and for a large range of X-ray energies are missing. Using a set of analytical functions, the SDD response functions were satisfactorily reproduced for the X-ray energy range 1-15 keV. The behaviour of the parameters involved in the SDD tailing functions with X-ray energy is described by simple polynomial functions, which permit an easy implementation in PIXE spectra fitting codes.
Influence of Response Prepotency Strength, General Working Memory Resources, and Specific Working Memory Load on the Ability to Inhibit Predominant Responses: A Comparison of Young and Elderly Participants

ERIC Educational Resources Information Center

Grandjean, Julien; Collette, Fabienne

2011-01-01

One conception of inhibitory functioning suggests that the ability to successfully inhibit a predominant response depends mainly on the strength of that response, the general functioning of working memory processes, and the working memory demand of the task (Roberts, Hager, & Heron, 1994). The proposal that inhibition and functional working memory…

Sexual Assertiveness Mediates the Associations Between Partner Facilitative Responses and Sexual Outcomes in Women With Provoked Vestibulodynia.

PubMed

McNicoll, Gabrielle; Corsini-Munt, Serena; O Rosen, Natalie; McDuff, Pierre; Bergeron, Sophie

2017-10-03

Provoked vestibulodynia (PVD) is a recurrent idiopathic vulvo-vaginal pain associated with negative sexual and psychological consequences. Facilitative partner responses to pain are currently receiving empirical attention because they are positively associated with women's sexual outcomes. However, the mechanisms through which facilitative responses to pain are associated with these outcomes have not been examined. One potential mechanism is sexual assertiveness, which has been found to be associated with better sexual function and satisfaction in women with PVD. The present study examined whether women's sexual assertiveness mediated the association between women's perception of facilitative partner responses and women's sexual function and satisfaction. Women (N = 140) with PVD symptomatology completed self-reported questionnaires evaluating their perception of their partners' facilitative responses, and their own sexual assertiveness, sexual function, and sexual satisfaction. Dependent measures were sexual function measured by the Female Sexual Function Index and sexual satisfaction assessed by the Global Measure of Sexual Satisfaction Scale. Results indicated that women's higher sexual assertiveness mediated the association between their greater perceived facilitative partner responses and their improved sexual function and satisfaction. Findings suggest a potential mechanism through which partner responses may be associated with women's sexual outcomes.
44 CFR 352.20 - Purpose and scope.

Code of Federal Regulations, 2014 CFR

2014-10-01

... providing Federal technical assistance to the licensee for developing its offsite emergency response plan... response functions which Federal agencies may be called upon to provide; (d) Describes the process for allocating responsibilities among Federal agencies for planning site-specific emergency response functions...
44 CFR 352.20 - Purpose and scope.

Code of Federal Regulations, 2013 CFR

2013-10-01

... providing Federal technical assistance to the licensee for developing its offsite emergency response plan... response functions which Federal agencies may be called upon to provide; (d) Describes the process for allocating responsibilities among Federal agencies for planning site-specific emergency response functions...
44 CFR 352.20 - Purpose and scope.

Code of Federal Regulations, 2012 CFR

2012-10-01

... providing Federal technical assistance to the licensee for developing its offsite emergency response plan... response functions which Federal agencies may be called upon to provide; (d) Describes the process for allocating responsibilities among Federal agencies for planning site-specific emergency response functions...
44 CFR 352.20 - Purpose and scope.

Code of Federal Regulations, 2011 CFR

2011-10-01

... providing Federal technical assistance to the licensee for developing its offsite emergency response plan... response functions which Federal agencies may be called upon to provide; (d) Describes the process for allocating responsibilities among Federal agencies for planning site-specific emergency response functions...
ARES: automated response function code. Users manual. [HPGAM and LSQVM

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

Maung, T.; Reynolds, G.M.

This ARES user's manual provides detailed instructions for a general understanding of the Automated Response Function Code and gives step by step instructions for using the complete code package on a HP-1000 system. This code is designed to calculate response functions of NaI gamma-ray detectors, with cylindrical or rectangular geometries.
Unruh effect for general trajectories

NASA Astrophysics Data System (ADS)

Obadia, N.; Milgrom, M.

2007-03-01

We consider two-level detectors coupled to a scalar field and moving on arbitrary trajectories in Minkowski space-time. We first derive a generic expression for the response function using a (novel) regularization procedure based on the Feynman prescription that is explicitly causal, and we compare it to other expressions used in the literature. We then use this expression to study, analytically and numerically, the time dependence of the response function in various nonstationarity situations. We show that, generically, the response function decreases like a power in the detector’s level spacing, E, for high E. It is only for stationary worldlines that the response function decays faster than any power law, in keeping with the known exponential behavior for some stationary cases. Under some conditions the (time-dependent) response function for a nonstationary worldline is well approximated by the value of the response function for a stationary worldline having the same instantaneous acceleration, torsion, and hypertorsion. While we cannot offer general conditions for this to apply, we discuss special cases; in particular, the low-energy limit for linear space trajectories.
Effects of Functionalization of TiO2 Nanotube Array Sensors with Pd Nanoparticles on Their Selectivity

PubMed Central

Park, Sunghoon; Kim, Soohyun; Park, Suyoung; Lee, Wan In; Lee, Chongmu

2014-01-01

This study compared the responses of Pd-functionalized and pristine titanate (TiO2) nanotube arrays to ethanol with those to acetone to determine the effects of functionalization of TiO2 nanotubes with Pd nanoparticles on the sensitivity and selectivity. The responses of pristine and Pd-functionalized TiO2 nanotube arrays to ethanol gas at 200 °C were ∼2877% and ∼21,253%, respectively. On the other hand, the responses of pristine and Pd-functionalized TiO2 nanotube arrays to acetone gas at 250 °C were ∼1636% and 8746% respectively. In the case of ethanol sensing, the response and recovery times of Pd-functionalized TiO2 nanotubes (10.2 and 7.1 s) were obviously shorter than those of pristine TiO2 nanotubes (14.3 and 8.8 s), respectively. In contrast, in the case of acetone sensing the response and recovery times of Pd-functionalized TiO2 nanotubes (42.5 and 19.7 s) were almost the same as those of pristine TiO2 nanotubes (47.2 and 17.9 s). TiO2 nanotube arrays showed the strongest response to ethanol and Pd functionalization was the most effective in improving the response of TiO2 nanotubes to ethanol among six different types of gases: ethanol, acetone, CO, H2, NH3 and NO2. The origin of the superior sensing properties of Pd-functionalized TiO2 nanotubes toward ethanol to acetone is also discussed. PMID:25166499
Response diversity determines the resilience of ecosystems to environmental change.

PubMed

Mori, Akira S; Furukawa, Takuya; Sasaki, Takehiro

2013-05-01

A growing body of evidence highlights the importance of biodiversity for ecosystem stability and the maintenance of optimal ecosystem functionality. Conservation measures are thus essential to safeguard the ecosystem services that biodiversity provides and human society needs. Current anthropogenic threats may lead to detrimental (and perhaps irreversible) ecosystem degradation, providing strong motivation to evaluate the response of ecological communities to various anthropogenic pressures. In particular, ecosystem functions that sustain key ecosystem services should be identified and prioritized for conservation action. Traditional diversity measures (e.g. 'species richness') may not adequately capture the aspects of biodiversity most relevant to ecosystem stability and functionality, but several new concepts may be more appropriate. These include 'response diversity', describing the variation of responses to environmental change among species of a particular community. Response diversity may also be a key determinant of ecosystem resilience in the face of anthropogenic pressures and environmental uncertainty. However, current understanding of response diversity is poor, and we see an urgent need to disentangle the conceptual strands that pervade studies of the relationship between biodiversity and ecosystem functioning. Our review clarifies the links between response diversity and the maintenance of ecosystem functionality by focusing on the insurance hypothesis of biodiversity and the concept of functional redundancy. We provide a conceptual model to describe how loss of response diversity may cause ecosystem degradation through decreased ecosystem resilience. We explicitly explain how response diversity contributes to functional compensation and to spatio-temporal complementarity among species, leading to long-term maintenance of ecosystem multifunctionality. Recent quantitative studies suggest that traditional diversity measures may often be uncoupled from measures (such as response diversity) that may be more effective proxies for ecosystem stability and resilience. Certain conclusions and recommendations of earlier studies using these traditional measures as indicators of ecosystem resilience thus may be suspect. We believe that functional ecology perspectives incorporating the effects and responses of diversity are essential for development of management strategies to safeguard (and restore) optimal ecosystem functionality (especially multifunctionality). Our review highlights these issues and we envision our work generating debate around the relationship between biodiversity and ecosystem functionality, and leading to improved conservation priorities and biodiversity management practices that maximize ecosystem resilience in the face of uncertain environmental change. © 2012 The Authors. Biological Reviews © 2012 Cambridge Philosophical Society.
Different kernel functions due to rainfall response from borehole strainmeter in Taiwan

NASA Astrophysics Data System (ADS)

Yen Chen, Chih; Hu, Jyr Ching; LIu, Chi Ching

2014-05-01

In order to realize reasons inducing earthquakes, project of monitoring of the fault activity using 3-component Gladwin Tensor Strainmeter (GTSM) has been initiated since 2003 in Taiwan, which is one of the most active seismic regions in the world. Observed strain contains several different effects within including barometric, tidal, groundwater, precipitation, tectonics, seismic and other irregular noise. After removing the response of tides and air pressure on strain, we still can find some anomalies highly related to the rainfall in short time in days. The strain response induced by rainfall can be separated into two parts as observation in groundwater, slow response and quick response, respectively. Quick response reflects the strain responding to the load of falling water drops on the ground surface. A kernel function shows the continual response induced by unit precipitation water in time domain. We split the quick response from data removing tidal and barometric response, and then calculate the kernel function by use of deconvolution method. More, an average kernel function was calculated to reduce the noise level. There are five of the sites installed by CGS Taiwan were selected to calculate kernel functions for individual sites. The results show there may be different on rainfall response in different environmental settings. In the case of stations site on gentle terrain, kernel function for each site shows the similar trend, it rises quickly to maximum in 1 to 2 hrs, and then goes down near to zero gently in period of 2-3 days. But in the case of sites settled side by the rivers, there will be 2nd peak of function when collected water in the catchment flows along by the sites related to the hydrograph of creeks. More, landslides will occur in some sites in hazard of landslide with more rainfall stored on, just like DARB in ChiaYi. The curve of kernel function will be controlled by landslides and debris flows.
Estimation of automobile-driver describing function from highway tests using the double steering wheel

NASA Technical Reports Server (NTRS)

Delp, P.; Crossman, E. R. F. W.; Szostak, H.

1972-01-01

The automobile-driver describing function for lateral position control was estimated for three subjects from frequency response analysis of straight road test results. The measurement procedure employed an instrumented full size sedan with known steering response characteristics, and equipped with a lateral lane position measuring device based on video detection of white stripe lane markings. Forcing functions were inserted through a servo driven double steering wheel coupling the driver to the steering system proper. Random appearing, Gaussian, and transient time functions were used. The quasi-linear models fitted to the random appearing input frequency response characterized the driver as compensating for lateral position error in a proportional, derivative, and integral manner. Similar parameters were fitted to the Gabor transformed frequency response of the driver to transient functions. A fourth term corresponding to response to lateral acceleration was determined by matching the time response histories of the model to the experimental results. The time histories show evidence of pulse-like nonlinear behavior during extended response to step transients which appear as high frequency remnant power.
Feeding on Multiple Sources: Towards a Universal Parameterization of the Functional Response of a Generalist Predator Allowing for Switching

PubMed Central

Morozov, Andrew; Petrovskii, Sergei

2013-01-01

Understanding of complex trophic interactions in ecosystems requires correct descriptions of the rate at which predators consume a variety of different prey species. Field and laboratory data on multispecies communities are rarely sufficient and usually cannot provide an unambiguous test for the theory. As a result, the conventional way of constructing a multi-prey functional response is speculative, and often based on assumptions that are difficult to verify. Predator responses allowing for prey selectivity and active switching are thought to be more biologically relevant compared to the standard proportion-based consumption. However, here we argue that the functional responses with switching may not be applicable to communities with a broad spectrum of resource types. We formulate a set of general rules that a biologically sound parameterization of a predator functional response should satisfy, and show that all existing formulations for the multispecies response with prey selectivity and switching fail to do so. Finally, we propose a universal framework for parameterization of a multi-prey functional response by combining patterns of food selectivity and proportion-based feeding. PMID:24086356
An uncertainty model of acoustic metamaterials with random parameters

NASA Astrophysics Data System (ADS)

He, Z. C.; Hu, J. Y.; Li, Eric

2018-01-01

Acoustic metamaterials (AMs) are man-made composite materials. However, the random uncertainties are unavoidable in the application of AMs due to manufacturing and material errors which lead to the variance of the physical responses of AMs. In this paper, an uncertainty model based on the change of variable perturbation stochastic finite element method (CVPS-FEM) is formulated to predict the probability density functions of physical responses of AMs with random parameters. Three types of physical responses including the band structure, mode shapes and frequency response function of AMs are studied in the uncertainty model, which is of great interest in the design of AMs. In this computation, the physical responses of stochastic AMs are expressed as linear functions of the pre-defined random parameters by using the first-order Taylor series expansion and perturbation technique. Then, based on the linear function relationships of parameters and responses, the probability density functions of the responses can be calculated by the change-of-variable technique. Three numerical examples are employed to demonstrate the effectiveness of the CVPS-FEM for stochastic AMs, and the results are validated by Monte Carlo method successfully.
Do parent protective responses mediate the relation between parent distress and child functional disability among children with chronic pain?

PubMed

Sieberg, Christine B; Williams, Sara; Simons, Laura E

2011-10-01

To examine whether protective parent responses mediate the relation between parent distress and child functioning. At a pain clinic evaluation, 157 families participated. Parents completed measures of global distress (BSI-18), distress in the context of their child's pain (BAP-PIQ), and protective responses to their child's pain. Children completed measures of functional disability and pain. BAP-PIQ subscales were significantly associated with child functional disability, whereas BSI subscales were unrelated. Protective parent responses partially mediated the relation between parent distress and child functional disability for depression, anxiety, and catastrophizing. However, parent protective behavior fully mediated the relationship between parent helplessness and child functional disability, indicating that feelings of parent helplessness did not uniquely contribute to child functional disability. Discussion Results suggest that when treating youth with chronic pain, parental distress in the context of children's pain needs to be addressed.
Effect of Reinforcer Magnitude on Performance Maintained by Progressive-Ratio Schedules

PubMed Central

Rickard, J.F; Body, S; Zhang, Z; Bradshaw, C.M; Szabadi, E

2009-01-01

This experiment examined the relationship between reinforcer magnitude and quantitative measures of performance on progressive-ratio schedules. Fifteen rats were trained under a progressive-ratio schedule in seven phases of the experiment in which the volume of a 0.6-M sucrose solution reinforcer was varied within the range 6–300 µl. Overall response rates in successive ratios conformed to a bitonic equation derived from Killeen's (1994) Mathematical Principles of Reinforcement. The “specific activation” parameter, a, which is presumed to reflect the incentive value of the reinforcer, was a monotonically increasing function of reinforcer volume; the “response time” parameter, δ, which defines the minimum response time, increased as a function of reinforcer volume; the “currency” parameter, β, which is presumed to reflect the coupling of responses to the reinforcer, declined as a function of volume. Running response rate (response rate calculated after exclusion of the postreinforcement pause) decayed monotonically as a function of ratio size; the index of curvature of this function increased as a function of reinforcer volume. Postreinforcement pause increased as a function of ratio size. Estimates of a derived from overall response rates and postreinforcement pauses showed a modest positive correlation across conditions and between animals. Implications of the results for the quantification of reinforcer value and for the use of progressive-ratio schedules in behavioral neuroscience are discussed. PMID:19230513
Effect of reinforcer magnitude on performance maintained by progressive-ratio schedules.

PubMed

Rickard, J F; Body, S; Zhang, Z; Bradshaw, C M; Szabadi, E

2009-01-01

This experiment examined the relationship between reinforcer magnitude and quantitative measures of performance on progressive-ratio schedules. Fifteen rats were trained under a progressive-ratio schedule in seven phases of the experiment in which the volume of a 0.6-M sucrose solution reinforcer was varied within the range 6-300 microl. Overall response rates in successive ratios conformed to a bitonic equation derived from Killeen's (1994) Mathematical Principles of Reinforcement. The "specific activation" parameter, a, which is presumed to reflect the incentive value of the reinforcer, was a monotonically increasing function of reinforcer volume; the "response time" parameter, delta, which defines the minimum response time, increased as a function of reinforcer volume; the "currency" parameter, beta, which is presumed to reflect the coupling of responses to the reinforcer, declined as a function of volume. Running response rate (response rate calculated after exclusion of the postreinforcement pause) decayed monotonically as a function of ratio size; the index of curvature of this function increased as a function of reinforcer volume. Postreinforcement pause increased as a function of ratio size. Estimates of a derived from overall response rates and postreinforcement pauses showed a modest positive correlation across conditions and between animals. Implications of the results for the quantification of reinforcer value and for the use of progressive-ratio schedules in behavioral neuroscience are discussed.
The relationship of systemic markers of renal function and vascular function with retinal blood vessel responses.

PubMed

Heitmar, R; Varma, C; De, P; Lau, Y C; Blann, A D

2016-11-01

To test the hypothesis of a significant relationship between systemic markers of renal and vascular function (processes linked to cardiovascular disease and its development) and retinal microvascular function in diabetes and/or cardiovascular disease. Ocular microcirculatory function was measured in 116 patients with diabetes and/or cardiovascular disease using static and continuous retinal vessel responses to three cycles of flickering light. Endothelial function was evaluated by von Willebrand factor (vWf), endothelial microparticles and soluble E selectin, renal function by serum creatinine, creatinine clearance and estimated glomerular filtration rate (eGFR). HbA1c was used as a control index. Central retinal vein equivalence and venous maximum dilation to flicker were linked to HbA1c (both p < 0.05). Arterial reaction time was linked to serum creatinine (p = 0.036) and eGFR (p = 0.039); venous reaction time was linked to creatinine clearance (p = 0.018). Creatinine clearance and eGFR were linked to arterial maximum dilatation (p < 0.001 and p = 0.003, respectively) and the dilatation amplitude (p = 0.038 and p = 0.048, respectively) responses in the third flicker cycle. Of venous responses to the first flicker cycle, HbA1c was linked to the maximum dilation response (p = 0.004) and dilatation amplitude (p = 0.017), vWf was linked to the maximum constriction response (p = 0.016), and creatinine clearance to the baseline diameter fluctuation (p = 0.029). In the second flicker cycle, dilatation amplitude was linked to serum creatinine (p = 0.022). Several retinal blood vessel responses to flickering light are linked to glycaemia and renal function, but only one index is linked to endothelial function. Renal function must be considered when interpreting retinal vessel responses.
Neutron spectrometry in a mixed field of neutrons and protons with a phoswich neutron detector Part I: response functions for photons and neutrons of the phoswich neutron detector

NASA Astrophysics Data System (ADS)

Takada, M.; Taniguchi, S.; Nakamura, T.; Nakao, N.; Uwamino, Y.; Shibata, T.; Fujitaka, K.

2001-06-01

We have developed a phoswich neutron detector consisting of an NE213 liquid scintillator surrounded by an NE115 plastic scintillator to distinguish photon and neutron events in a charged-particle mixed field. To obtain the energy spectra by unfolding, the response functions to neutrons and photons were obtained by the experiment and calculation. The response functions to photons were measured with radionuclide sources, and were calculated with the EGS4-PRESTA code. The response functions to neutrons were measured with a white neutron source produced by the bombardment of 135 MeV protons onto a Be+C target using a TOF method, and were calculated with the SCINFUL code, which we revised in order to calculate neutron response functions up to 135 MeV. Based on these experimental and calculated results, response matrices for photons up to 20 MeV and neutrons up to 132 MeV could finally be obtained.
Executive functioning complaints and escitalopram treatment response in late-life depression.

PubMed

Manning, Kevin J; Alexopoulos, George S; Banerjee, Samprit; Morimoto, Sarah Shizuko; Seirup, Joanna K; Klimstra, Sibel A; Yuen, Genevieve; Kanellopoulos, Theodora; Gunning-Dixon, Faith

2015-05-01

Executive dysfunction may play a key role in the pathophysiology of late-life depression. Executive dysfunction can be assessed with cognitive tests and subjective report of difficulties with executive skills. The present study investigated the association between subjective report of executive functioning complaints and time to escitalopram treatment response in older adults with major depressive disorder (MDD). 100 older adults with MDD (58 with executive functioning complaints and 42 without executive functioning complaints) completed a 12-week trial of escitalopram. Treatment response over 12 weeks, as measured by repeated Hamilton Depression Rating Scale scores, was compared for adults with and without executive complaints using mixed-effects modeling. Mixed effects analysis revealed a significant group × time interaction, F(1, 523.34) = 6.00, p = 0.01. Depressed older adults who reported executive functioning complaints at baseline demonstrated a slower response to escitalopram treatment than those without executive functioning complaints. Self-report of executive functioning difficulties may be a useful prognostic indicator for subsequent speed of response to antidepressant medication. Copyright © 2015 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.
Functional diversity response to hardwood forest management varies across taxa and spatial scales.

PubMed

Murray, Bryan D; Holland, Jeffrey D; Summerville, Keith S; Dunning, John B; Saunders, Michael R; Jenkins, Michael A

2017-06-01

Contemporary forest management offers a trade-off between the potential positive effects of habitat heterogeneity on biodiversity, and the potential harm to mature forest communities caused by habitat loss and perforation of the forest canopy. While the response of taxonomic diversity to forest management has received a great deal of scrutiny, the response of functional diversity is largely unexplored. However, functional diversity may represent a more direct link between biodiversity and ecosystem function. To examine how forest management affects diversity at multiple spatial scales, we analyzed a long-term data set that captured changes in taxonomic and functional diversity of moths (Lepidoptera), longhorned beetles (Coleoptera: Cerambycidae), and breeding birds in response to contemporary silvicultural systems in oak-hickory hardwood forests. We used these data sets to address the following questions: how do even- and uneven-aged silvicultural systems affect taxonomic and functional diversity at the scale of managed landscapes compared to the individual harvested and unharvested forest patches that comprise the landscapes, and how do these silvicultural systems affect the functional similarity of assemblages at the scale of managed landscapes and patches? Due to increased heterogeneity within landscapes, we expected even-aged silviculture to increase and uneven-aged silviculture to decrease functional diversity at the landscape level regardless of impacts at the patch level. Functional diversity responses were taxon-specific with respect to the direction of change and time since harvest. Responses were also consistent across patch and landscape levels within each taxon. Moth assemblage species richness, functional richness, and functional divergence were negatively affected by harvesting, with stronger effects resulting from uneven-aged than even-aged management. Longhorned beetle assemblages exhibited a peak in species richness two years after harvesting, while functional diversity metrics did not differ between harvested and unharvested patches and managed landscapes. The species and functional richness of breeding bird assemblages increased in response to harvesting with more persistent effects in uneven- than in even-aged managed landscapes. For moth and bird assemblages, species turnover was driven by species with more extreme trait combinations. Our study highlights the variability of multi-taxon functional diversity in response to forest management across multiple spatial scales. © 2017 by the Ecological Society of America.

Effects of spatial grouping on the functional response of predators

USGS Publications Warehouse

Cosner, C.; DeAngelis, D.L.; Ault, J.S.; Olson, D.B.

1999-01-01

A unified mechanistic approach is given for the derivation of various forms of functional response in predator-prey models. The derivation is based on the principle-of-mass action but with the crucial refinement that the nature of the spatial distribution of predators and/or opportunities for predation are taken into account in an implicit way. If the predators are assumed to have a homogeneous spatial distribution, then the derived functional response is prey-dependent. If the predators are assumed to form a dense colony or school in a single (possibly moving) location, or if the region where predators can encounter prey is assumed to be of limited size, then the functional response depends on both predator and prey densities in a manner that reflects feeding interference between predators. Depending on the specific assumptions, the resulting functional response may be of Beddington-DeAngelis type, of Hassell-Varley type, or ratio-dependent.
Strain-specific functional and numerical responses are required to evaluate impacts on predator-prey dynamics.

PubMed

Yang, Zhou; Lowe, Chris D; Crowther, Will; Fenton, Andy; Watts, Phillip C; Montagnes, David J S

2013-02-01

We use strains recently collected from the field to establish cultures; then, through laboratory studies we investigate how among strain variation in protozoan ingestion and growth rates influences population dynamics and intraspecific competition. We focused on the impact of changing temperature because of its well-established effects on protozoan rates and its ecological relevance, from daily fluctuations to climate change. We show, first, that there is considerable inter-strain variability in thermal sensitivity of maximum growth rate, revealing distinct differences among multiple strains of our model species Oxyrrhis marina. We then intensively examined two representative strains that exhibit distinctly different thermal responses and parameterised the influence of temperature on their functional and numerical responses. Finally, we assessed how these responses alter predator-prey population dynamics. We do this first considering a standard approach, which assumes that functional and numerical responses are directly coupled, and then compare these results with a novel framework that incorporates both functional and numerical responses in a fully parameterised model. We conclude that: (i) including functional diversity of protozoa at the sub-species level will alter model predictions and (ii) including directly measured, independent functional and numerical responses in a model can provide a more realistic account of predator-prey dynamics.
Functional response of wolves preying on barren-ground caribou in a multiple-prey ecosystem

USGS Publications Warehouse

Dale, B.W.; Adams, Layne G.; Bowyer, R.T.

1994-01-01

1. We investigated the functional response of wolves (Canis lupus) to varying abundance of ungulate prey to test the hypothesis that switching from alternate prey to preferred prey results in regulation of a caribou (Rangifer tarandus) population at low densities. 2. We determined prey selection, kill rates, and prey abundance for four wolf packs during three 30-day periods in March 1989, March 1990, November 1990, and created a simple discrete model to evaluate the potential for the expected numerical and observed functional responses of wolves to regulate caribou populations. 3. We observed a quickly decelerating type II functional response that, in the absence of numerical response, implicates an anti-regulatory effect of wolf predation on barren-ground caribou dynamics. 4. There was little potential for regulation caused by the multiplicative effect of increasing functional and numerical responses because of presence of alternative prey. This resulted in high wolf:caribou ratios at low prey densities which precluded the effects of an increasing functional response. 5. Inversely density-dependent predation by other predators, such as bears, reduces the potential for predators to regulate caribou populations at low densities, and small reductions in predation by one predator may have disproportionately large effects on the total predation rate.
Response functions for dimers and square-symmetric molecules in four-wave-mixing experiments with polarized light

NASA Astrophysics Data System (ADS)

Smith, Eric Ryan; Farrow, Darcie A.; Jonas, David M.

2005-07-01

Four-wave-mixing nonlinear-response functions are given for intermolecular and intramolecular vibrations of a perpendicular dimer and intramolecular vibrations of a square-symmetric molecule containing a doubly degenerate state. A two-dimensional particle-in-a-box model is used to approximate the electronic wave functions and obtain harmonic potentials for nuclear motion. Vibronic interactions due to symmetry-lowering distortions along Jahn-Teller active normal modes are discussed. Electronic dephasing due to nuclear motion along both symmetric and asymmetric normal modes is included in these response functions, but population transfer between states is not. As an illustration, these response functions are used to predict the pump-probe polarization anisotropy in the limit of impulsive excitation.
Maturation of Sensori-Motor Functional Responses in the Preterm Brain.

PubMed

Allievi, Alessandro G; Arichi, Tomoki; Tusor, Nora; Kimpton, Jessica; Arulkumaran, Sophie; Counsell, Serena J; Edwards, A David; Burdet, Etienne

2016-01-01

Preterm birth engenders an increased risk of conditions like cerebral palsy and therefore this time may be crucial for the brain's developing sensori-motor system. However, little is known about how cortical sensori-motor function matures at this time, whether development is influenced by experience, and about its role in spontaneous motor behavior. We aimed to systematically characterize spatial and temporal maturation of sensori-motor functional brain activity across this period using functional MRI and a custom-made robotic stimulation device. We studied 57 infants aged from 30 + 2 to 43 + 2 weeks postmenstrual age. Following both induced and spontaneous right wrist movements, we saw consistent positive blood oxygen level-dependent functional responses in the contralateral (left) primary somatosensory and motor cortices. In addition, we saw a maturational trend toward faster, higher amplitude, and more spatially dispersed functional responses; and increasing integration of the ipsilateral hemisphere and sensori-motor associative areas. We also found that interhemispheric functional connectivity was significantly related to ex-utero exposure, suggesting the influence of experience-dependent mechanisms. At term equivalent age, we saw a decrease in both response amplitude and interhemispheric functional connectivity, and an increase in spatial specificity, culminating in the establishment of a sensori-motor functional response similar to that seen in adults. © The Author 2015. Published by Oxford University Press.
Loss-of-function mutations in the ethylene receptor ETR1 cause enhanced sensitivity and exaggerated response to ethylene in Arabidopsis.

PubMed

Cancel, Jesse D; Larsen, Paul B

2002-08-01

Ethylene signaling in Arabidopsis begins at a family of five ethylene receptors that regulate activity of a downstream mitogen-activated protein kinase kinase kinase, CTR1. Triple and quadruple loss-of-function ethylene receptor mutants display a constitutive ethylene response phenotype, indicating they function as negative regulators in this pathway. No ethylene-related phenotype has been described for single loss-of-function receptor mutants, although it was reported that etr1 loss-of-function mutants display a growth defect limiting plant size. In actuality, this apparent growth defect results from enhanced responsiveness to ethylene; a phenotype manifested in all tissues tested. The phenotype displayed by etr1 loss-of-function mutants was rescued by treatment with an inhibitor of ethylene perception, indicating that it is ethylene dependent. Identification of an ethylene-dependent phenotype for a loss-of-function receptor mutant gave a unique opportunity for genetic and biochemical analysis of upstream events in ethylene signaling, including demonstration that the dominant ethylene-insensitive phenotype of etr2-1 is partially dependent on ETR1. This work demonstrates that mutational loss of the ethylene receptor ETR1 alters responsiveness to ethylene in Arabidopsis and that enhanced ethylene response in Arabidopsis not only results in increased sensitivity but exaggeration of response.
Loss-of-Function Mutations in the Ethylene Receptor ETR1 Cause Enhanced Sensitivity and Exaggerated Response to Ethylene in Arabidopsis

PubMed Central

Cancel, Jesse D.; Larsen, Paul B.

2002-01-01

Ethylene signaling in Arabidopsis begins at a family of five ethylene receptors that regulate activity of a downstream mitogen-activated protein kinase kinase kinase, CTR1. Triple and quadruple loss-of-function ethylene receptor mutants display a constitutive ethylene response phenotype, indicating they function as negative regulators in this pathway. No ethylene-related phenotype has been described for single loss-of-function receptor mutants, although it was reported that etr1 loss-of-function mutants display a growth defect limiting plant size. In actuality, this apparent growth defect results from enhanced responsiveness to ethylene; a phenotype manifested in all tissues tested. The phenotype displayed by etr1 loss-of-function mutants was rescued by treatment with an inhibitor of ethylene perception, indicating that it is ethylene dependent. Identification of an ethylene-dependent phenotype for a loss-of-function receptor mutant gave a unique opportunity for genetic and biochemical analysis of upstream events in ethylene signaling, including demonstration that the dominant ethylene-insensitive phenotype of etr2-1 is partially dependent on ETR1. This work demonstrates that mutational loss of the ethylene receptor ETR1 alters responsiveness to ethylene in Arabidopsis and that enhanced ethylene response in Arabidopsis not only results in increased sensitivity but exaggeration of response. PMID:12177468
Responsiveness of outcome measures for upper limb prosthetic rehabilitation.

PubMed

Resnik, Linda; Borgia, Matthew

2016-02-01

There is limited research on responsiveness of prosthetic rehabilitation outcome measures. To examine responsiveness of the Box and Block test, Jebsen-Taylor Hand Function tests, Upper Extremity Functional Scale, University of New Brunswick skill and spontaneity tests, Activity Measure for Upper Limb Amputation, and the Patient-Specific Functional Scale. This was a quasi-experimental study with repeated measurements in a convenience sample of upper limb amputees. Measures were collected before, during, and after training with the DEKA Arm. Largest effect sizes were observed for Patient-Specific Functional Scale (effect size: 1.59, confidence interval: 1.00, 2.14), Activity Measure for Upper Limb Amputation (effect size: 1.33, confidence interval: 0.73, 1.90), and University of New Brunswick skill test (effect size: 1.18, confidence interval: 0.61, 1.73). Other measures that were responsive to change were Box and Block test, Jebsen-Taylor Hand Function light and heavy can tests, and University of New Brunswick spontaneity test. Responsiveness and pattern of responsiveness varied by prosthetic level. The Box and Block test, Jebsen-Taylor Hand Function light and heavy can tests, University of New Brunswick skill and spontaneity tests, Activities Measure for Upper Limb Amputation, and the Patient-Specific Functional Scale were responsive to change during prosthetic training. These findings have implications for choice of measures for research and practice and inform clinicians about the amount of training necessary to maximize outcomes with the DEKA Arm. Findings on responsiveness of outcome measures have implications for the choice of measures for clinical trials and practice. Findings regarding the responsiveness to change over the course of training can inform clinicians about the amount of training that may be necessary to maximize specific outcomes with the DEKA Arm. © The International Society for Prosthetics and Orthotics 2014.
20 CFR 220.121 - Responsibility for assessing and determining residual functional capacity.

Code of Federal Regulations, 2010 CFR

2010-04-01

... residual functional capacity. 220.121 Section 220.121 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT DETERMINING DISABILITY Residual Functional Capacity § 220.121 Responsibility for assessing and determining residual functional capacity. (a) For cases at the initial or...
20 CFR 220.121 - Responsibility for assessing and determining residual functional capacity.

Code of Federal Regulations, 2011 CFR

2011-04-01

... residual functional capacity. 220.121 Section 220.121 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT DETERMINING DISABILITY Residual Functional Capacity § 220.121 Responsibility for assessing and determining residual functional capacity. (a) For cases at the initial or...
A method for decoding the neurophysiological spike-response transform

PubMed Central

Stern, Estee; García-Crescioni, Keyla; Miller, Mark W.; Peskin, Charles S.; Brezina, Vladimir

2009-01-01

Many physiological responses elicited by neuronal spikes—intracellular calcium transients, synaptic potentials, muscle contractions—are built up of discrete, elementary responses to each spike. However, the spikes occur in trains of arbitrary temporal complexity, and each elementary response not only sums with previous ones, but can itself be modified by the previous history of the activity. A basic goal in system identification is to characterize the spike-response transform in terms of a small number of functions—the elementary response kernel and additional kernels or functions that describe the dependence on previous history—that will predict the response to any arbitrary spike train. Here we do this by developing further and generalizing the “synaptic decoding” approach of Sen et al. (J Neurosci 16:6307-6318, 1996). Given the spike times in a train and the observed overall response, we use least-squares minimization to construct the best estimated response and at the same time best estimates of the elementary response kernel and the other functions that characterize the spike-response transform. We avoid the need for any specific initial assumptions about these functions by using techniques of mathematical analysis and linear algebra that allow us to solve simultaneously for all of the numerical function values treated as independent parameters. The functions are such that they may be interpreted mechanistically. We examine the performance of the method as applied to synthetic data. We then use the method to decode real synaptic and muscle contraction transforms. PMID:19695289
A Quasi-Parametric Method for Fitting Flexible Item Response Functions

ERIC Educational Resources Information Center

Liang, Longjuan; Browne, Michael W.

2015-01-01

If standard two-parameter item response functions are employed in the analysis of a test with some newly constructed items, it can be expected that, for some items, the item response function (IRF) will not fit the data well. This lack of fit can also occur when standard IRFs are fitted to personality or psychopathology items. When investigating…
41 CFR 102-3.115 - What are the responsibilities and functions of an agency Committee Management Officer (CMO)?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false What are the responsibilities and functions of an agency Committee Management Officer (CMO)? 102-3.115 Section 102-3.115 Public...? § 102-3.115 What are the responsibilities and functions of an agency Committee Management Officer (CMO...
GADRAS Detector Response Function.

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

Mitchell, Dean J.; Harding, Lee; Thoreson, Gregory G

2014-11-01

The Gamma Detector Response and Analysis Software (GADRAS) applies a Detector Response Function (DRF) to compute the output of gamma-ray and neutron detectors when they are exposed to radiation sources. The DRF is fundamental to the ability to perform forward calculations (i.e., computation of the response of a detector to a known source), as well as the ability to analyze spectra to deduce the types and quantities of radioactive material to which the detectors are exposed. This document describes how gamma-ray spectra are computed and the significance of response function parameters that define characteristics of particular detectors.
Invertibility of retarded response functions for Laplace transformable potentials: Application to one-body reduced density matrix functional theory.

PubMed

Giesbertz, K J H

2015-08-07

A theorem for the invertibility of arbitrary response functions is presented under the following conditions: the time dependence of the potentials should be Laplace transformable and the initial state should be a ground state, though it might be degenerate. This theorem provides a rigorous foundation for all density-functional-like theories in the time-dependent linear response regime. Especially for time-dependent one-body reduced density matrix (1RDM) functional theory, this is an important step forward, since a solid foundation has currently been lacking. The theorem is equally valid for static response functions in the non-degenerate case, so can be used to characterize the uniqueness of the potential in the ground state version of the corresponding density-functional-like theory. Such a classification of the uniqueness of the non-local potential in ground state 1RDM functional theory has been lacking for decades. With the aid of presented invertibility theorem presented here, a complete classification of the non-uniqueness of the non-local potential in 1RDM functional theory can be given for the first time.
Oral neutrophil responses to acute prolonged exercise may not be representative of blood neutrophil responses.

PubMed

Davison, Glen; Jones, Arwel Wyn

2015-03-01

Neutrophil numbers and function (oxidative burst) were assessed in peripheral blood and oral samples before and after prolonged exercise. Blood neutrophil count increased (∼3.5-fold, P < 0.001) and function decreased (30% ± 19% decrease, P = 0.005) postexercise. Oral neutrophil count (P = 0.392) and function (P = 0.334) were unchanged. Agreement between oral and blood neutrophil function responses to exercise was poor. These findings highlight the importance of studying neutrophils within various compartments/sample types.
Implementation of the zooplankton functional response in plankton models: State of the art, recent challenges and future directions

NASA Astrophysics Data System (ADS)

Morozov, Andrew; Poggiale, Jean-Christophe; Cordoleani, Flora

2012-09-01

The conventional way of describing grazing in plankton models is based on a zooplankton functional response framework, according to which the consumption rate is computed as the product of a certain function of food (the functional response) and the density/biomass of herbivorous zooplankton. A large amount of literature on experimental feeding reports the existence of a zooplankton functional response in microcosms and small mesocosms, which goes a long way towards explaining the popularity of this framework both in mean-field (e.g. NPZD models) and spatially resolved models. On the other hand, the complex foraging behaviour of zooplankton (feeding cycles) as well as spatial heterogeneity of food and grazer distributions (plankton patchiness) across time and space scales raise questions as to the existence of a functional response of herbivores in vivo. In the current review, we discuss limitations of the ‘classical’ zooplankton functional response and consider possible ways to amend this framework to cope with the complexity of real planktonic ecosystems. Our general conclusion is that although the functional response of herbivores often does not exist in real ecosystems (especially in the form observed in the laboratory), this framework can be rather useful in modelling - but it does need some amendment which can be made based on various techniques of model reduction. We also show that the shape of the functional response depends on the spatial resolution (‘frame’) of the model. We argue that incorporating foraging behaviour and spatial heterogeneity in plankton models would not necessarily require the use of individual based modelling - an approach which is now becoming dominant in the literature. Finally, we list concrete future directions and challenges and emphasize the importance of a closer collaboration between plankton biologists and modellers in order to make further progress towards better descriptions of zooplankton grazing.
A narrow repertoire of transcriptional modules responsive to pyogenic bacteria is impaired in patients carrying loss-of-function mutations in MYD88 or IRAK4

PubMed Central

Alsina, L; Israelsson, E; Altman, MC; Dang, KK; Ghandil, P; Israel, L; von Bernuth, H; Baldwin, N; Qin, H; Jin, Z; Banchereau, R; Anguiano, E; Ionan, A; Abel, L; Puel, A; Picard, C; Pascual, V; Casanova, JL; Chaussabel, D

2014-01-01

Loss of function in the kinase IRAK-4 or the adapter MyD88 in humans interrupts a pathway critical for pathogen sensing and ignition of inflammation. Yet patients with loss of function mutations are surprisingly only susceptible to a limited range of pathogens. We employed a systems approach to investigate transcriptome responses following in vitro exposure of patients’ blood to Toll-like receptor and interleukin-1 receptor agonists, and whole pathogens. Responses to purified agonists were globally abolished but variable residual responses were present following exposure to whole pathogens. Further dissection of the latter responses identified a narrow repertoire of immune transcriptional programs affected by loss of MyD88 or IRAK-4 function. This work introduces the use of a systems approach for the global assessment of innate immune responses, and the characterization of human primary immunodeficiencies. PMID:25344726
Identification of Linear and Nonlinear Aerodynamic Impulse Responses Using Digital Filter Techniques

NASA Technical Reports Server (NTRS)

Silva, Walter A.

1997-01-01

This paper discusses the mathematical existence and the numerically-correct identification of linear and nonlinear aerodynamic impulse response functions. Differences between continuous-time and discrete-time system theories, which permit the identification and efficient use of these functions, will be detailed. Important input/output definitions and the concept of linear and nonlinear systems with memory will also be discussed. It will be shown that indicial (step or steady) responses (such as Wagner's function), forced harmonic responses (such as Theodorsen's function or those from doublet lattice theory), and responses to random inputs (such as gusts) can all be obtained from an aerodynamic impulse response function. This paper establishes the aerodynamic impulse response function as the most fundamental, and, therefore, the most computationally efficient, aerodynamic function that can be extracted from any given discrete-time, aerodynamic system. The results presented in this paper help to unify the understanding of classical two-dimensional continuous-time theories with modern three-dimensional, discrete-time theories. First, the method is applied to the nonlinear viscous Burger's equation as an example. Next the method is applied to a three-dimensional aeroelastic model using the CAP-TSD (Computational Aeroelasticity Program - Transonic Small Disturbance) code and then to a two-dimensional model using the CFL3D Navier-Stokes code. Comparisons of accuracy and computational cost savings are presented. Because of its mathematical generality, an important attribute of this methodology is that it is applicable to a wide range of nonlinear, discrete-time problems.
Identification of Linear and Nonlinear Aerodynamic Impulse Responses Using Digital Filter Techniques

NASA Technical Reports Server (NTRS)

Silva, Walter A.

1997-01-01

This paper discusses the mathematical existence and the numerically-correct identification of linear and nonlinear aerodynamic impulse response functions. Differences between continuous-time and discrete-time system theories, which permit the identification and efficient use of these functions, will be detailed. Important input/output definitions and the concept of linear and nonlinear systems with memory will also be discussed. It will be shown that indicial (step or steady) responses (such as Wagner's function), forced harmonic responses (such as Tbeodorsen's function or those from doublet lattice theory), and responses to random inputs (such as gusts) can all be obtained from an aerodynamic impulse response function. This paper establishes the aerodynamic impulse response function as the most fundamental, and, therefore, the most computationally efficient, aerodynamic function that can be extracted from any given discrete-time, aerodynamic system. The results presented in this paper help to unify the understanding of classical two-dimensional continuous-time theories with modem three-dimensional, discrete-time theories. First, the method is applied to the nonlinear viscous Burger's equation as an example. Next the method is applied to a three-dimensional aeroelastic model using the CAP-TSD (Computational Aeroelasticity Program - Transonic Small Disturbance) code and then to a two-dimensional model using the CFL3D Navier-Stokes code. Comparisons of accuracy and computational cost savings are presented. Because of its mathematical generality, an important attribute of this methodology is that it is applicable to a wide range of nonlinear, discrete-time problems.

Electromagnetic scaling functions within the Green's function Monte Carlo approach

DOE PAGES

Rocco, N.; Alvarez-Ruso, L.; Lovato, A.; ...

2017-07-24

We have studied the scaling properties of the electromagnetic response functions of 4He and 12C nuclei computed by the Green's function Monte Carlo approach, retaining only the one-body current contribution. Longitudinal and transverse scaling functions have been obtained in the relativistic and nonrelativistic cases and compared to experiment for various kinematics. The characteristic asymmetric shape of the scaling function exhibited by data emerges in the calculations in spite of the nonrelativistic nature of the model. The results are mostly consistent with scaling of zeroth, first, and second kinds. Our analysis reveals a direct correspondence between the scaling and the nucleon-densitymore » response functions. In conclusion, the scaling function obtained from the proton-density response displays scaling of the first kind, even more evidently than the longitudinal and transverse scaling functions« less
Electromagnetic scaling functions within the Green's function Monte Carlo approach

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

Rocco, N.; Alvarez-Ruso, L.; Lovato, A.

We have studied the scaling properties of the electromagnetic response functions of 4He and 12C nuclei computed by the Green's function Monte Carlo approach, retaining only the one-body current contribution. Longitudinal and transverse scaling functions have been obtained in the relativistic and nonrelativistic cases and compared to experiment for various kinematics. The characteristic asymmetric shape of the scaling function exhibited by data emerges in the calculations in spite of the nonrelativistic nature of the model. The results are mostly consistent with scaling of zeroth, first, and second kinds. Our analysis reveals a direct correspondence between the scaling and the nucleon-densitymore » response functions. In conclusion, the scaling function obtained from the proton-density response displays scaling of the first kind, even more evidently than the longitudinal and transverse scaling functions« less
Changes in Early Adolescents' Sense of Responsibility to their Parents in the United States and China: Implications for Academic Functioning

PubMed Central

Pomerantz, Eva M.; Qin, Lili; Wang, Qian; Chen, Huichang

2011-01-01

This research examined American and Chinese children's sense of responsibility to their parents during early adolescence, with a focus on its implications for children's academic functioning. Four times over the seventh and eighth grades, 825 children (mean age = 12.73 years) in the United States and China reported on their sense of responsibility to their parents. Information on children's academic functioning was also collected from children as well as school records. Although children's sense of responsibility to their parents declined over the seventh and eighth grades in the United States, this was not the case in China. In both countries, children's sense of responsibility was predictive of enhanced academic functioning among children over time. PMID:21466541
HEALTH SIGNIFICANCE OF PULMONARY FUNCTION TESTS

EPA Science Inventory

As the sensitivity and precision of functional tests improves, we become increasingly able to measure responses to pollutant exposures with little, if any, demonstrable health significance. Proper interpretation of such functional responses generally requires an ability to evalua...
Computer method for identification of boiler transfer functions

NASA Technical Reports Server (NTRS)

Miles, J. H.

1972-01-01

Iterative computer aided procedure was developed which provides for identification of boiler transfer functions using frequency response data. Method uses frequency response data to obtain satisfactory transfer function for both high and low vapor exit quality data.
Intelligent biointerface: remote control for hydrophilic-hydrophobic property of the material surfaces by temperature

NASA Astrophysics Data System (ADS)

Okano, Teruo; Kikuchi, Akihiko

1996-04-01

Considerable research attention has been focused recently on materials which change their structure and properties in response to external stimuli. These materials, termed `intelligent materials', sense a stimulus as a signal (sensor function), judge the magnitude of this signal (processor function), and then alter their function in direct response (effector function). Introduction of stimuli-responsive polymers as switching sequences into both artificial materials and bioactive molecules would permit external, stimuli-induced modulation of their structures and `on-off' switching of their respective functions at molecular levels. Intelligent materials embodying these concepts would contribute to the establishment of basic principles for fabricating novel systems which modulate their structural changes and functional changes in response to external stimuli. These materials are attractive not only as new, sophisticated biomaterials but also for utilization in protein biotechnology, medical diagnosis and advanced site-specific drug delivery system.
Scaling within the spectral function approach

NASA Astrophysics Data System (ADS)

Sobczyk, J. E.; Rocco, N.; Lovato, A.; Nieves, J.

2018-03-01

Scaling features of the nuclear electromagnetic response functions unveil aspects of nuclear dynamics that are crucial for interpreting neutrino- and electron-scattering data. In the large momentum-transfer regime, the nucleon-density response function defines a universal scaling function, which is independent of the nature of the probe. In this work, we analyze the nucleon-density response function of 12C, neglecting collective excitations. We employ particle and hole spectral functions obtained within two distinct many-body methods, both widely used to describe electroweak reactions in nuclei. We show that the two approaches provide compatible nucleon-density scaling functions that for large momentum transfers satisfy first-kind scaling. Both methods yield scaling functions characterized by an asymmetric shape, although less pronounced than that of experimental scaling functions. This asymmetry, only mildly affected by final state interactions, is mostly due to nucleon-nucleon correlations, encoded in the continuum component of the hole spectral function.
Acute pulmonary function response to ozone in young adults as a function of body mass index

EPA Science Inventory

Recent studies have shown enhanced responsiveness to ozone in obese mice. Adiposity has not been examined as a possible modulator of ozone response in humans. We therefore examined the relationship between body mass index and the acute spirometric response to ozone (O(3)) exposur...
Population dynamics and mutualism: Functional responses of benefits and costs

USGS Publications Warehouse

Holland, J. Nathaniel; DeAngelis, Donald L.; Bronstein, Judith L.

2002-01-01

We develop an approach for studying population dynamics resulting from mutualism by employing functional responses based on density‐dependent benefits and costs. These functional responses express how the population growth rate of a mutualist is modified by the density of its partner. We present several possible dependencies of gross benefits and costs, and hence net effects, to a mutualist as functions of the density of its partner. Net effects to mutualists are likely a monotonically saturating or unimodal function of the density of their partner. We show that fundamental differences in the growth, limitation, and dynamics of a population can occur when net effects to that population change linearly, unimodally, or in a saturating fashion. We use the mutualism between senita cactus and its pollinating seed‐eating moth as an example to show the influence of different benefit and cost functional responses on population dynamics and stability of mutualisms. We investigated two mechanisms that may alter this mutualism's functional responses: distribution of eggs among flowers and fruit abortion. Differences in how benefits and costs vary with density can alter the stability of this mutualism. In particular, fruit abortion may allow for a stable equilibrium where none could otherwise exist.
Neutron light output response and resolution functions in EJ-309 liquid scintillation detectors

DOE PAGES

Enqvist, Andreas; Lawrence, Christopher C.; Wieger, Brian M.; ...

2013-03-26

Here, the neutron light output response functions and detector resolution functions were measured at Ohio University's tandem Van de Graaff generator for three cylindrical EJ-309 liquid scintillator cells, having dimensions 12.7(circle divide)-by-12.7, 7.6-by-7.6, and 7.6-by-5.1 cm. A 7.44 MeV deuteron beam was used on an Al-27 target generating a continuous spectrum over the energy range from a few hundred keV to over 10 MeV. The light output response functions are determined using an exponential fit. Detector resolution functions are obtained for the 12.7-by-12.7 and 7.6-by-7.6 cm detectors. It is demonstrated that the dependence on detector size is important for themore » light output response functions, but not to the same extent for the resolution function, even when photomultiplier tubes, detector material, and other detector characteristics are carefully matched.« less
Responsiveness of pain and disability measures for chronic whiplash.

PubMed

Stewart, Mark; Maher, Christopher G; Refshauge, Kathryn M; Bogduk, Nikolai; Nicholas, Michael

2007-03-01

Cohort study. To evaluate the responsiveness of common pain and disability measures in a cohort of patients with chronic whiplash. Pain and disability are routinely measured in clinical practice and clinical research. However, to date, a head-to-head comparison of competing measures for whiplash patients has not been performed. Pain (pain intensity, bothersomeness, and SF-36 bodily pain score) and disability (Patient Specific Functional Scale, Neck Disability Index, Functional Rating Index, Copenhagen Scale, and SF-36 physical summary) measures were completed by 132 patients with chronic whiplash at baseline and then again after 6 weeks together with an 11-point global perceived effect scale. Internal responsiveness was evaluated by calculating effect sizes and standardized response means, and external responsiveness by correlating change scores with global perceived effect scores and by ROC curves. The ranking of responsiveness was consistent across the different analyses. Pain bothersomeness was more responsive than pain intensity, which was more responsive than the SF-36 pain measure. The Patient Specific Functional Scale was the most responsive disability measure, followed by the spine-specific measures, with the SF-36 physical summary measure the least responsive. Pain bothersomeness and the Patient Specific Functional Scale provide the most responsive measures of pain and disability, respectively, in patients with chronic whiplash.
Endogenous extra-cellular heat shock protein 72: releasing signal(s) and function.

PubMed

Fleshner, M; Johnson, J D

2005-08-01

Exposure to acute physical and/or psychological stressors induces a cascade of physiological changes collectively termed the stress response. The stress response is demonstrable at the behavioural, neural, endocrine and cellular levels. Stimulation of the stress response functions to improve an organism's chance of survival during acute stressor challenge. The current review focuses on one ubiquitous cellular stress response, up-regulation of heat shock protein 72 (Hsp72). Although a great deal is known about the function of intra-cellular Hsp72 during exposure to acute stressors, little is understood about the potential function of endogenous extra-cellular Hsp72 (eHsp72). The current review will develop the hypothesis that eHsp72 release may be a previously unrecognized feature of the acute stress response and may function as an endogenous 'danger signal' for the immune system. Specifically, it is proposed that exposure to physical or psychological acute stressors stimulate the release of endogenous eHsp72 into the blood via an alpha1-adrenergic receptor-mediated mechanism and that elevated eHsp72 functions to facilitate innate immunity in the presence of bacterial challenge.
The effect of stimulus strength on the speed and accuracy of a perceptual decision.

PubMed

Palmer, John; Huk, Alexander C; Shadlen, Michael N

2005-05-02

Both the speed and the accuracy of a perceptual judgment depend on the strength of the sensory stimulation. When stimulus strength is high, accuracy is high and response time is fast; when stimulus strength is low, accuracy is low and response time is slow. Although the psychometric function is well established as a tool for analyzing the relationship between accuracy and stimulus strength, the corresponding chronometric function for the relationship between response time and stimulus strength has not received as much consideration. In this article, we describe a theory of perceptual decision making based on a diffusion model. In it, a decision is based on the additive accumulation of sensory evidence over time to a bound. Combined with simple scaling assumptions, the proportional-rate and power-rate diffusion models predict simple analytic expressions for both the chronometric and psychometric functions. In a series of psychophysical experiments, we show that this theory accounts for response time and accuracy as a function of both stimulus strength and speed-accuracy instructions. In particular, the results demonstrate a close coupling between response time and accuracy. The theory is also shown to subsume the predictions of Piéron's Law, a power function dependence of response time on stimulus strength. The theory's analytic chronometric function allows one to extend theories of accuracy to response time.
In Vivo Function of Tryptophans in the Arabidopsis UV-B Photoreceptor UVR8[W

PubMed Central

O’Hara, Andrew; Jenkins, Gareth I.

2012-01-01

Arabidopsis thaliana UV RESISTANCE LOCUS8 (UVR8) is a photoreceptor specifically for UV-B light that initiates photomorphogenic responses in plants. UV-B exposure causes rapid conversion of UVR8 from dimer to monomer, accumulation in the nucleus, and interaction with CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1), which functions with UVR8 in UV-B responses. Studies in yeast and with purified UVR8 implicate several tryptophan amino acids in UV-B photoreception. However, their roles in UV-B responses in plants, and the functional significance of all 14 UVR8 tryptophans, are not known. Here we report the functions of the UVR8 tryptophans in vivo. Three tryptophans in the β-propeller core are important in maintaining structural stability and function of UVR8. However, mutation of three other core tryptophans and four at the dimeric interface has no apparent effect on function in vivo. Mutation of three tryptophans implicated in UV-B photoreception, W233, W285, and W337, impairs photomorphogenic responses to different extents. W285 is essential for UVR8 function in plants, whereas W233 is important but not essential for function, and W337 has a lesser role. Ala mutants of these tryptophans appear monomeric and constitutively bind COP1 in plants, but their responses indicate that monomer formation and COP1 binding are not sufficient for UVR8 function. PMID:23012433
A time-frequency analysis method to obtain stable estimates of magnetotelluric response function based on Hilbert-Huang transform

NASA Astrophysics Data System (ADS)

Cai, Jianhua

2017-05-01

The time-frequency analysis method represents signal as a function of time and frequency, and it is considered a powerful tool for handling arbitrary non-stationary time series by using instantaneous frequency and instantaneous amplitude. It also provides a possible alternative to the analysis of the non-stationary magnetotelluric (MT) signal. Based on the Hilbert-Huang transform (HHT), a time-frequency analysis method is proposed to obtain stable estimates of the magnetotelluric response function. In contrast to conventional methods, the response function estimation is performed in the time-frequency domain using instantaneous spectra rather than in the frequency domain, which allows for imaging the response parameter content as a function of time and frequency. The theory of the method is presented and the mathematical model and calculation procedure, which are used to estimate response function based on HHT time-frequency spectrum, are discussed. To evaluate the results, response function estimates are compared with estimates from a standard MT data processing method based on the Fourier transform. All results show that apparent resistivities and phases, which are calculated from the HHT time-frequency method, are generally more stable and reliable than those determined from the simple Fourier analysis. The proposed method overcomes the drawbacks of the traditional Fourier methods, and the resulting parameter minimises the estimation bias caused by the non-stationary characteristics of the MT data.
Multi-Stimuli-Responsive Polymer Materials: Particles, Films, and Bulk Gels.

PubMed

Cao, Zi-Quan; Wang, Guo-Jie

2016-06-01

Stimuli-responsive polymers have received tremendous attention from scientists and engineers for several decades due to the wide applications of these smart materials in biotechnology and nanotechnology. Driven by the complex functions of living systems, multi-stimuli-responsive polymer materials have been designed and developed in recent years. Compared with conventional single- or dual-stimuli-based polymer materials, multi-stimuli-responsive polymer materials would be more intriguing since more functions and finer modulations can be achieved through more parameters. This critical review highlights the recent advances in this area and focuses on three types of multi-stimuli-responsive polymer materials, namely, multi-stimuli-responsive particles (micelles, micro/nanogels, vesicles, and hybrid particles), multi-stimuli-responsive films (polymer brushes, layer-by-layer polymer films, and porous membranes), and multi-stimuli-responsive bulk gels (hydrogels, organogels, and metallogels) from recent publications. Various stimuli, such as light, temperature, pH, reduction/oxidation, enzymes, ions, glucose, ultrasound, magnetic fields, mechanical stress, solvent, voltage, and electrochemistry, have been combined to switch the functions of polymers. The polymer design, preparation, and function of multi-stimuli-responsive particles, films, and bulk gels are comprehensively discussed here. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Environmental limits to growth: physiological niche boundaries of corals along turbidity-light gradients.

PubMed

Anthony, Kenneth R N; Connolly, Sean R

2004-11-01

The physiological responses of organisms to resources and environmental conditions are important determinants of niche boundaries. In previous work, functional relationships between organism energetics and environment have been limited to energy intakes. However, energetic costs of maintenance may also depend on the supply of resources. In many mixotrophic organisms, two such resource types are light and particle concentration (turbidity). Using two coral species with contrasting abundances along light and turbidity gradients (Acropora valida and Turbinaria mesenterina), we incorporate the dual resource-stressor roles of these variables by calibrating functional responses of energy costs (respiration and loss of organic carbon) as well as energy intake (photosynthesis and particle feeding). This allows us to characterize physiological niche boundaries along light and turbidity gradients, identify species-specific differences in these boundaries, and assess the sensitivity of these differences to interspecific differences in particular functional response parameters. The turbidity-light niche of T. mesenterina was substantially larger than that of A. valida, consistent with its broader ecological distribution. As expected, the responses of photosynthesis, heterotrophic capacity, respiration, and organic carbon loss to light and turbidity varied between species. Niche boundaries were highly sensitive to the functional responses of energy costs to light and turbidity. Moreover, the study species' niche differences were almost entirely attributable to species-specific differences in one functional response: that of respiration to turbidity. These results demonstrate that functional responses of energy-loss processes are important determinants of species-specific physiological limits to growth, and thereby of niche differences in reef corals. Given that many resources can stress organisms when supply rates are high, we propose that the functional responses of energy losses will prove to be important determinants of niche differences in other systems as well.
48 CFR 42.603 - Responsibilities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Responsibilities. (a) The CACO shall perform, on a corporate-wide basis, the contract administration functions as designated by the responsible agency. Typical CACO functions include (1) the determination of final indirect cost rates for cost-reimbursement contracts, (2) establishment of advance agreements or recommendations...
Dynamic current-current susceptibility in three-dimensional Dirac and Weyl semimetals

NASA Astrophysics Data System (ADS)

Thakur, Anmol; Sadhukhan, Krishanu; Agarwal, Amit

2018-01-01

We study the linear response of doped three-dimensional Dirac and Weyl semimetals to vector potentials, by calculating the wave-vector- and frequency-dependent current-current response function analytically. The longitudinal part of the dynamic current-current response function is then used to study the plasmon dispersion and the optical conductivity. The transverse response in the static limit yields the orbital magnetic susceptibility. In a Weyl semimetal, along with the current-current response function, all these quantities are significantly impacted by the presence of parallel electric and magnetic fields (a finite E .B term) and can be used to experimentally explore the chiral anomaly.
Novel function of Trim44 promotes an antiviral response by stabilizing VISA.

PubMed

Yang, Bo; Wang, Jie; Wang, Yanming; Zhou, Haiyan; Wu, Xiaodong; Tian, Zhigang; Sun, Bing

2013-04-01

Virus-induced signaling adaptor (VISA) functions as a critical adaptor in the regulation of both the production of type I IFNs and the subsequent control of the innate antiviral response. In this study, we demonstrate that tripartite motif (Trim)44 interacts with VISA and promotes VISA-mediated antiviral responses. The overexpression of Trim44 enhances the cellular response to viral infection, whereas Trim44 knockdown yields the opposite effect. Trim44 stabilizes VISA by preventing VISA ubiquitination and degradation. These findings suggest that Trim44 functions as a positive regulator of the virus-triggered immune response by enhancing the stability of VISA.

Cone photoreceptor sensitivities and unique hue chromatic responses: correlation and causation imply the physiological basis of unique hues.

PubMed

Pridmore, Ralph W

2013-01-01

This paper relates major functions at the start and end of the color vision process. The process starts with three cone photoreceptors transducing light into electrical responses. Cone sensitivities were once expected to be Red Green Blue color matching functions (to mix colors) but microspectrometry proved otherwise: they instead peak in yellowish, greenish, and blueish hues. These physiological functions are an enigma, unmatched with any set of psychophysical (behavioral) functions. The end-result of the visual process is color sensation, whose essential percepts are unique (or pure) hues red, yellow, green, blue. Unique hues cannot be described by other hues, but can describe all other hues, e.g., that hue is reddish-blue. They are carried by four opponent chromatic response curves but the literature does not specify whether each curve represents a range of hues or only one hue (a unique) over its wavelength range. Here the latter is demonstrated, confirming that opponent chromatic responses define, and may be termed, unique hue chromatic responses. These psychophysical functions also are an enigma, unmatched with any physiological functions or basis. Here both enigmas are solved by demonstrating the three cone sensitivity curves and the three spectral chromatic response curves are almost identical sets (Pearson correlation coefficients r from 0.95-1.0) in peak wavelengths, curve shapes, math functions, and curve crossover wavelengths, though previously unrecognized due to presentation of curves in different formats, e.g., log, linear. (Red chromatic response curve is largely nonspectral and thus derives from two cones.) Close correlation combined with deterministic causation implies cones are the physiological basis of unique hues. This match of three physiological and three psychophysical functions is unique in color vision.
Cone Photoreceptor Sensitivities and Unique Hue Chromatic Responses: Correlation and Causation Imply the Physiological Basis of Unique Hues

PubMed Central

Pridmore, Ralph W.

2013-01-01

This paper relates major functions at the start and end of the color vision process. The process starts with three cone photoreceptors transducing light into electrical responses. Cone sensitivities were once expected to be Red Green Blue color matching functions (to mix colors) but microspectrometry proved otherwise: they instead peak in yellowish, greenish, and blueish hues. These physiological functions are an enigma, unmatched with any set of psychophysical (behavioral) functions. The end-result of the visual process is color sensation, whose essential percepts are unique (or pure) hues red, yellow, green, blue. Unique hues cannot be described by other hues, but can describe all other hues, e.g., that hue is reddish-blue. They are carried by four opponent chromatic response curves but the literature does not specify whether each curve represents a range of hues or only one hue (a unique) over its wavelength range. Here the latter is demonstrated, confirming that opponent chromatic responses define, and may be termed, unique hue chromatic responses. These psychophysical functions also are an enigma, unmatched with any physiological functions or basis. Here both enigmas are solved by demonstrating the three cone sensitivity curves and the three spectral chromatic response curves are almost identical sets (Pearson correlation coefficients r from 0.95–1.0) in peak wavelengths, curve shapes, math functions, and curve crossover wavelengths, though previously unrecognized due to presentation of curves in different formats, e.g., log, linear. (Red chromatic response curve is largely nonspectral and thus derives from two cones.) Close correlation combined with deterministic causation implies cones are the physiological basis of unique hues. This match of three physiological and three psychophysical functions is unique in color vision. PMID:24204755
Application of Statistic Experimental Design to Assess the Effect of Gammairradiation Pre-Treatment on the Drying Characteristics and Qualities of Wheat

NASA Astrophysics Data System (ADS)

Yu, Yong; Wang, Jun

Wheat, pretreated by 60Co gamma irradiation, was dried by hot-air with irradiation dosage 0-3 kGy, drying temperature 40-60 °C, and initial moisture contents 19-25% (drying basis). The drying characteristics and dried qualities of wheat were evaluated based on drying time, average dehydration rate, wet gluten content (WGC), moisture content of wet gluten (MCWG)and titratable acidity (TA). A quadratic rotation-orthogonal composite experimental design, with three variables (at five levels) and five response functions, and analysis method were employed to study the effect of three variables on the individual response functions. The five response functions (drying time, average dehydration rate, WGC, MCWG, TA) correlated with these variables by second order polynomials consisting of linear, quadratic and interaction terms. A high correlation coefficient indicated the suitability of the second order polynomial to predict these response functions. The linear, interaction and quadratic effects of three variables on the five response functions were all studied.
Measurements of response functions of EJ-299-33A plastic scintillator for fast neutrons

NASA Astrophysics Data System (ADS)

Hartman, J.; Barzilov, A.; Peters, E. E.; Yates, S. W.

2015-12-01

Monoenergetic neutron response functions were measured for an EJ-299-33A plastic scintillator. The 7-MV Van de Graaff accelerator at the University of Kentucky Accelerator Laboratory was used to produce proton and deuteron beams for reactions with gaseous tritium and deuterium targets, yielding monoenergetic neutrons by means of the 3H(p,n)3He, 2H(d,n)3He, and 3H(d,n)4He reactions. The neutron energy was selected by tuning the charged-particle's energy and using the angular dependence of the neutron emission. The resulting response functions were measured for 0.1-MeV steps in neutron energy from 0.1 MeV to 8.2 MeV and from 12.2 MeV to 20.2 MeV. Experimental data were processed using a procedure for digital pulse-shape discrimination, which allowed characterization of the response functions of the plastic scintillator to neutrons only. The response functions are intended for use in neutron spectrum unfolding methods.
Functional analysis of HPV-like particle-activated Langerhans cells in vitro.

PubMed

Yan, Lisa; Woodham, Andrew W; Da Silva, Diane M; Kast, W Martin

2015-01-01

Langerhans cells (LCs) are antigen-presenting cells responsible for initiating an immune response against human papillomaviruses (HPVs) entering the epithelial layer in vivo as they are the first immune cell that HPV comes into contact with. LCs become activated in response to foreign antigens, which causes internal signaling resulting in the increased expression of co-stimulatory molecules and the secretion of inflammatory cytokines. Functionally activated LCs are then capable of migrating to the lymph nodes where they interact with antigen-specific T cells and initiate an adaptive T-cell response in vivo. However, HPV has evolved in a manner that suppresses LC function, and thus the induction of antigen-specific T cells is hindered. While many methods exist to monitor the activity of LCs in vitro, the migration and induction of cytotoxic T cells is ultimately indicative of a functional immune response. Here, methods in analyzing functional migration and induction of antigen-specific T cells after stimulation of LCs with HPV virus-like particles in vitro are described.
Estimation of the auto frequency response function at unexcited points using dummy masses

NASA Astrophysics Data System (ADS)

Hosoya, Naoki; Yaginuma, Shinji; Onodera, Hiroshi; Yoshimura, Takuya

2015-02-01

If structures with complex shapes have space limitations, vibration tests using an exciter or impact hammer for the excitation are difficult. Although measuring the auto frequency response function at an unexcited point may not be practical via a vibration test, it can be obtained by assuming that the inertia acting on a dummy mass is an external force on the target structure upon exciting a different excitation point. We propose a method to estimate the auto frequency response functions at unexcited points by attaching a small mass (dummy mass), which is comparable to the accelerometer mass. The validity of the proposed method is demonstrated by comparing the auto frequency response functions estimated at unexcited points in a beam structure to those obtained from numerical simulations. We also consider random measurement errors by finite element analysis and vibration tests, but not bias errors. Additionally, the applicability of the proposed method is demonstrated by applying it to estimate the auto frequency response function of the lower arm in a car suspension.
Changes in early adolescents' sense of responsibility to their parents in the United States and China: implications for academic functioning.

PubMed

Pomerantz, Eva M; Qin, Lili; Wang, Qian; Chen, Huichang

2011-01-01

This research examined American and Chinese children's sense of responsibility to their parents during early adolescence, with a focus on its implications for children's academic functioning. Four times over the seventh and eighth grades, 825 children (mean age = 12.73 years) in the United States and China reported on their sense of responsibility to their parents. Information on children's academic functioning was also collected from children as well as school records. Although children's sense of responsibility to their parents declined over the seventh and eighth grades in the United States, this was not the case in China. In both countries, children's sense of responsibility was predictive of enhanced academic functioning among children over time. © 2011 The Authors. Child Development © 2011 Society for Research in Child Development, Inc.
Determination of a response function of a thermocouple using a short acoustic pulse.

PubMed

Tashiro, Yusuke; Biwa, Tetsushi; Yazaki, Taichi

2007-04-01

This paper reports on an experimental technique to determine a response function of a thermocouple using a short acoustic pulse wave. A pulse of 10 ms is generated in a tube filled with 1 bar helium gas. The temperature is measured using the thermocouple. The reference temperature is deduced from the measured pressure on the basis of a laminar oscillating flow theory. The response function of the thermocouple is obtained as a function of frequency below 50 Hz through a comparison between the measured and reference temperatures.
Response functions for neutron skyshine analysis

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

Gui, A.A.; Shultis, J.K.; Faw, R.E.

1997-02-01

Neutron and associated secondary photon line-beam response functions (LBRFs) for point monodirectional neutron sources are generated using the MCNP Monte Carlo code for use in neutron skyshine analysis employing the integral line-beam method. The LBRFs are evaluated at 14 neutron source energies ranging from 0.01 to 14 MeV and at 18 emission angles from 1 to 170 deg, as measured from the source-to-detector axis. The neutron and associated secondary photon conical-beam response functions (CBRFs) for azimuthally symmetric neutron sources are also evaluated at 13 neutron source energies in the same energy range and at 13 polar angles of source collimationmore » from 1 to 89 deg. The response functions are approximated by an empirical three-parameter function of the source-to-detector distance. These response function approximations are available for a source-to-detector distance up to 2,500 m and, for the first time, give dose equivalent responses that are required for modern radiological assessments. For the CBRFs, ground correction factors for neutrons and secondary photons are calculated and also approximated by empirical formulas for use in air-over-ground neutron skyshine problems with azimuthal symmetry. In addition, simple procedures are proposed for humidity and atmospheric density corrections.« less
Emergence of ratio-dependent and predator-dependent functional responses for pollination mutualism and seed parasitism

USGS Publications Warehouse

DeAngelis, Donald L.; Holland, J. Nathaniel

2006-01-01

Prey (N) dependence [g(N)], predator (P) dependence [g(P) or g(N,P)], and ratio dependence [f(P/N)] are often seen as contrasting forms of the predator's functional response describing predator consumption rates on prey resources in predator–prey and parasitoid–host interactions. Analogously, prey-, predator-, and ratio-dependent functional responses are apparently alternative functional responses for other types of consumer–resource interactions. These include, for example, the fraction of flowers pollinated or seeds parasitized in pollination (pre-dispersal) seed-parasitism mutualisms, such as those between fig wasps and fig trees or yucca moths and yucca plants. Here we examine the appropriate functional responses for how the fraction of flowers pollinated and seeds parasitized vary with the density of pollinators (predator dependence) or the ratio of pollinator and flower densities (ratio dependence). We show that both types of functional responses can emerge from minor, but biologically important variations on a single model. An individual-based model was first used to describe plant–pollinator interactions. Conditional upon on whether the number of flowers visited by the pollinator was limited by factors other than search time (e.g., by the number of eggs it had to lay, if it was also a seed parasite), and on whether the pollinator could directly find flowers on a plant, or had to search, the simulation results lead to either a predator-dependent or a ratio-dependent functional response. An analytic model was then used to show mathematically how these two cases can arise.
Functional Roles of Syk in Macrophage-Mediated Inflammatory Responses

PubMed Central

Yi, Young-Su; Son, Young-Jin; Ryou, Chongsuk; Sung, Gi-Ho; Kim, Jong-Hoon; Cho, Jae Youl

2014-01-01

Inflammation is a series of complex biological responses to protect the host from pathogen invasion. Chronic inflammation is considered a major cause of diseases, such as various types of inflammatory/autoimmune diseases and cancers. Spleen tyrosine kinase (Syk) was initially found to be highly expressed in hematopoietic cells and has been known to play crucial roles in adaptive immune responses. However, recent studies have reported that Syk is also involved in other biological functions, especially in innate immune responses. Although Syk has been extensively studied in adaptive immune responses, numerous studies have recently presented evidence that Syk has critical functions in macrophage-mediated inflammatory responses and is closely related to innate immune response. This review describes the characteristics of Syk-mediated signaling pathways, summarizes the recent findings supporting the crucial roles of Syk in macrophage-mediated inflammatory responses and diseases, and discusses Syk-targeted drug development for the therapy of inflammatory diseases. PMID:25045209
Responsiveness of the cervical Northern American Spine Society questionnaire (NASS) and the Short Form 36 (SF-36) in chronic whiplash.

PubMed

Angst, Felix; Verra, Martin L; Lehmann, Susanne; Gysi, Françoise; Benz, Thomas; Aeschlimann, André

2012-02-01

To determine and compare the sensitivity to change of the condition-specific cervical Northern American Spine Society (NASS) and the generic Short Form 36 (SF-36). Prospective cohort study. One hundred and seventy five patients after whiplash injury. Four-week inpatient interdisciplinary pain management programme. MAIN MEASURES, ANALYSIS: Responsiveness of the NASS and the SF-36 was quantified by effect size and standardized response mean and compared within the same construct by the modified Jacknife test. Ability to detect improvement was compared using sensitivities determined from receiver operating characteristics curves. In pain, the NASS was comparable responsive to the SF-36 at the one-month follow-up (n = 175): effect sizes: 0.62 (NASS) versus 0.61 (SF-36), P = 0.914. The NASS was less responsive than the SF-36 in function: 0.23 versus 0.63, P < 0.001 and in pain+function: 0.35 versus 0.58 (P = 0.001). These relationships remained consistent using standardized response means, at the six-month follow-up (n = 103), and in the comparison of the sensitivities. Sensitivities at one month, pain: 70% (NASS) versus 62% (SF-36), P = 0.234; function: 65% versus 80%, P = 0.002; pain+function: 68% versus 78%, P = 0.035. The six-month data were similar. The generic SF-36 was more responsive in function and equally responsive in pain when compared to the condition-specific NASS. The SF-36 can be recommended as a responsive instrument for measurement of pain and function in chronic whiplash syndrome.
A double expansion method for the frequency response of finite-length beams with periodic parameters

NASA Astrophysics Data System (ADS)

Ying, Z. G.; Ni, Y. Q.

2017-03-01

A double expansion method for the frequency response of finite-length beams with periodic distribution parameters is proposed. The vibration response of the beam with spatial periodic parameters under harmonic excitations is studied. The frequency response of the periodic beam is the function of parametric period and then can be expressed by the series with the product of periodic and non-periodic functions. The procedure of the double expansion method includes the following two main steps: first, the frequency response function and periodic parameters are expanded by using identical periodic functions based on the extension of the Floquet-Bloch theorem, and the period-parametric differential equation for the frequency response is converted into a series of linear differential equations with constant coefficients; second, the solutions to the linear differential equations are expanded by using modal functions which satisfy the boundary conditions, and the linear differential equations are converted into algebraic equations according to the Galerkin method. The expansion coefficients are obtained by solving the algebraic equations and then the frequency response function is finally determined. The proposed double expansion method can uncouple the effects of the periodic expansion and modal expansion so that the expansion terms are determined respectively. The modal number considered in the second expansion can be reduced remarkably in comparison with the direct expansion method. The proposed double expansion method can be extended and applied to the other structures with periodic distribution parameters for dynamics analysis. Numerical results on the frequency response of the finite-length periodic beam with various parametric wave numbers and wave amplitude ratios are given to illustrate the effective application of the proposed method and the new frequency response characteristics, including the parameter-excited modal resonance, doubling-peak frequency response and remarkable reduction of the maximum frequency response for certain parametric wave number and wave amplitude. The results have the potential application to structural vibration control.
49 CFR 260.53 - Lenders' functions and responsibilities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Lenders' functions and responsibilities. 260.53 Section 260.53 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD... REHABILITATION AND IMPROVEMENT FINANCING PROGRAM Loan Guarantees-Lenders § 260.53 Lenders' functions and...
A Show of Hands: Relations between Young Children's Gesturing and Executive Function

ERIC Educational Resources Information Center

O'Neill, Gina; Miller, Patricia H.

2013-01-01

This study brought together 2 literatures--gesturing and executive function--in order to examine the possible role of gesture in children's executive function. Children (N = 41) aged 2½-6 years performed a sorting-shift executive function task (Dimensional Change Card Sort). Responses of interest included correct sorting, response latency,…
Erectile Dysfunction Precedes Coronary Artery Endothelial Dysfunction in Rats Fed a High-Fat, High-Sucrose, Western Pattern Diet

PubMed Central

La Favor, Justin D.; Anderson, Ethan J.; Hickner, Robert C.; Wingard, Christopher J.

2016-01-01

Introduction It is suggested that erectile dysfunction (ED) may be an early risk factor for cardiovascular disease. Aim The goal of this study was to determine whether development of ED precedes the onset of coronary artery endothelial dysfunction in response to a Western diet (WD), thereby establishing whether the WD differentially impacts the endothelium in a time-dependent manner. Additionally, a goal was to determine if diet-induced ED is reversible with intracavernosal sepiapterin treatment. Methods Male Sprague-Dawley rats were fed a WD for 4, 8, or 12 weeks, or a control diet for 8 weeks. Erectile function was evaluated by measuring the mean arterial pressure (MAP) and intracavernosal pressure (ICP) in response to electrical field stimulation of the cavernosal nerve near the major pelvic ganglion, in the absence and presence of sepiapterin. Coronary artery endothelial function was evaluated ex vivo with cumulative doses of acetylcholine (ACh) applied to segments of the left anterior descending coronary artery preconstricted with serotonin. Main Outcome Measures Erectile function was assessed as the ICP response to electrical field stimulation (EFS), normalized to MAP. Coronary artery endothelial function was assessed as the effective concentration producing 50% of a maximal response (EC50) of the ACh response. Results The ICP/MAP response to EFS was significantly attenuated following both 8 and 12 weeks of the WD compared with the control diet (P < 0.05). Sepiapterin treatment augmented the ICP/MAP response in all WD groups (P < 0.05). The coronary artery EC50 of the ACh response was not different from control following 4 or 8 weeks but was significantly elevated following 12 weeks of the WD (P < 0.01). Conclusions These data suggest that erectile function is reduced prior to coronary artery endothelial function in response to the WD. Improvement of erectile function with sepiapterin in WD rats indicates that nitric oxide synthase uncoupling is a key mechanism in diet-induced ED. PMID:23170997
Single-joint outcome measures: preliminary validation of patient-reported outcomes and physical examination.

PubMed

Heald, Alison E; Fudman, Edward J; Anklesaria, Pervin; Mease, Philip J

2010-05-01

To assess the validity, responsiveness, and reliability of single-joint outcome measures for determining target joint (TJ) response in patients with inflammatory arthritis. Patient-reported outcomes (PRO), consisting of responses to single questions about TJ global status on a 100-mm visual analog scale (VAS; TJ global score), function on a 100-mm VAS (TJ function score), and pain on a 5-point Likert scale (TJ pain score) were piloted in 66 inflammatory arthritis subjects in a phase 1/2 clinical study of an intraarticular gene transfer agent and compared to physical examination measures (TJ swelling, TJ tenderness) and validated function questionnaires (Disabilities of the Arm, Shoulder and Hand scale, Rheumatoid Arthritis Outcome Score, and the Health Assessment Questionnaire). Construct validity was assessed by evaluating the correlation between the single-joint outcome measures and validated function questionnaires using Spearman's rank correlation. Responsiveness or sensitivity to change was assessed through calculating effect size and standardized response means (SRM). Reliability of physical examination measures was assessed by determining interobserver agreement. The single-joint PRO were highly correlated with each other and correlated well with validated functional measures. The TJ global score exhibited modest effect size and modest SRM that correlated well with the patient's assessment of response on a 100-mm VAS. Physical examination measures exhibited high interrater reliability, but correlated less well with validated functional measures and the patient's assessment of response. Single-joint PRO, particularly the TJ global score, are simple to administer and demonstrate construct validity and responsiveness in patients with inflammatory arthritis. (ClinicalTrials.gov identifier NCT00126724).
A loss-of-function mutation in the nucleoporin AtNUP160 indicates that normal auxin signalling is required for a proper ethylene response in Arabidopsis

PubMed Central

Robles, Linda M.; Deslauriers, Stephen D.; Alvarez, Ashley A.; Larsen, Paul B.

2012-01-01

As part of a continuing effort to elucidate mechanisms that regulate the magnitude of ethylene signalling, an Arabidopsis mutant with an enhanced ethylene response was identified. Subsequent characterization of this loss-of-function mutant revealed severe hypocotyl shortening in the presence of saturating ethylene along with increased expression in leaves of a subset of ethylene-responsive genes. It was subsequently determined by map-based cloning that the mutant (sar1-7) represents a loss-of-function mutation in the previously described nucleoporin AtNUP160 (At1g33410, SAR1). In support of previously reported results, the sar1-7 mutant partially restored auxin responsiveness to roots of an rce1 loss-of-function mutant, indicating that AtNUP160/SAR1 is required for proper expression of factors responsible for the repression of auxin signalling. Analysis of arf7-1/sar1-7 and arf19-1/sar1-7 double mutants revealed that mutations affecting either ARF7 or ARF19 function almost fully blocked manifestation of the sar1-7-dependent ethylene hypersensitivity phenotype, suggesting that ARF7- and ARF19-mediated auxin signalling is responsible for regulating the magnitude of and/or competence for the ethylene response in Arabidopsis etiolated hypocotyls. Consistent with this, addition of auxin to ethylene-treated seedlings resulted in severe hypocotyl shortening, reminiscent of that seen for other eer (enhanced ethylene response) mutants, suggesting that auxin functions in part synergistically with ethylene to control hypocotyl elongation and other ethylene-dependent phenomena. PMID:22238449
Identifying ultrasensitive HGF dose-response functions in a 3D mammalian system for synthetic morphogenesis.

PubMed

Senthivel, Vivek Raj; Sturrock, Marc; Piedrafita, Gabriel; Isalan, Mark

2016-12-16

Nonlinear responses to signals are widespread natural phenomena that affect various cellular processes. Nonlinearity can be a desirable characteristic for engineering living organisms because it can lead to more switch-like responses, similar to those underlying the wiring in electronics. Steeper functions are described as ultrasensitive, and can be applied in synthetic biology by using various techniques including receptor decoys, multiple co-operative binding sites, and sequential positive feedbacks. Here, we explore the inherent non-linearity of a biological signaling system to identify functions that can potentially be exploited using cell genome engineering. For this, we performed genome-wide transcription profiling to identify genes with ultrasensitive response functions to Hepatocyte Growth Factor (HGF). We identified 3,527 genes that react to increasing concentrations of HGF, in Madin-Darby canine kidney (MDCK) cells, grown as cysts in 3D collagen cell culture. By fitting a generic Hill function to the dose-responses of these genes we obtained a measure of the ultrasensitivity of HGF-responsive genes, identifying a subset with higher apparent Hill coefficients (e.g. MMP1, TIMP1, SNORD75, SNORD86 and ERRFI1). The regulatory regions of these genes are potential candidates for future engineering of synthetic mammalian gene circuits requiring nonlinear responses to HGF signalling.
Numerical and functional responses of intestinal helminths in three rajid skates: evidence for competition between parasites?

PubMed

Randhawa, Haseeb S

2012-11-01

Host-parasite interactions generally involve communities of parasites. Within these communities, species will co-exist and/or interact with one another in a manner either benefiting the species involved or to the detriment of one or more of the species. At the level of helminth infracommunities, evidence for intra- and inter-specific competition includes numerical responses, i.e. those regulating helminth intensity of infection, and functional responses, i.e. where the presence of competitors modifies the realised niche of infrapopulations. The objectives of this study are to assess the numerical and functional responses of helminths in infracommunities from 3 rajid skates using general linear models. Despite a lack of numerical responses, functional responses to intra- and inter-specific interactions were observed. A positive correlation between the number of individuals in an infrapopulation and its niche breadth (functional response) was observed for the tapeworms Pseudanthobothrium spp. and Echeneibothrium spp., in all their respective hosts, and for the nematode Pseudanisakis sp. in the little skate. Evidence for inter-specific competition includes niche shifts in Pseudanthobothrium purtoni (ex little skate) and Pseudanisakis sp. (ex thorny skate) in the presence of Pseudanisakis sp. and the tapeworm Grillotia sp., respectively. These results are consistent with other studies in providing evidence for competition between helminths of skates.

Functional response to cardiac resynchronization therapy is associated with improved clinical outcome and absence of appropriate shocks.

PubMed

Van Boven, Nick; Bogaard, Kjell; Ruiter, Jaap; Kimman, Geert; Theuns, Dominic; Kardys, Isabella; Umans, Victor

2013-03-01

We evaluated clinical outcome and incidence of (in)appropriate shocks in consecutive chronic heart failure (CHF) patients treated with CRT with a defibrillator (CRT-D) according to functional response status. Furthermore, we investigated which factors predict such functional response. In a large teaching hospital, 179 consecutive CHF patients received CRT-D in 2005-2010. Patients were considered functional responders if left ventricular ejection fraction (LVEF) increased to ≥ 35% postimplantation. Analysis was performed on 142 patients, who had CRT-D as primary prevention, complete data and a baseline LVEF <35%. Endpoints consisted of all-cause mortality, heart failure (HF) hospitalizations, appropriate shocks and inappropriate shocks. Median follow-up was 3.0 years (interquartile range [IQR] 1.6-4.4) and median baseline LVEF was 20% (IQR 18-25%). The functional response-group consisted of 42 patients. In this group no patients died, none were hospitalized for HF, none received appropriate shocks and 3 patients (7.1%) received ≥ 1 inappropriate shocks. In comparison, the functional nonresponse group consisted of 100 patients, of whom 22 (22%) died (P = 0.003), 17 (17%) were hospitalized for HF (P = 0.007), 17 (17%) had ≥ 1 appropriate shocks (P = 0.003) and 8 (8.1%) received ≥ 1 inappropriate shocks (P = 0.78). Multivariable analysis showed that left bundle branch block (LBBB), QRS duration ≥ 150 milliseconds and no need for diuretics at baseline are independent predictors of functional response. Functional responders to CRT have a good prognosis and rarely need ICD therapy. LBBB, QRS duration ≥ 150 milliseconds and lack of chronic diuretic use predict functional response. © 2012 Wiley Periodicals, Inc.
Altered Reward Function in Adolescent Depression: What, When, and How?

PubMed Central

Forbes, Erika E.; Dahl, Ronald E.

2011-01-01

Background Conceptual models and recent evidence indicate that neural response to reward is altered in depression. Taking a developmental approach to investigating reward function in adolescent depression can elucidate the etiology, pathophysiology, and course of depression, a disorder that typically begins during adolescence and has high rates of recurrence. Methods This conceptual review describes the what, when, and how of altered reward function in adolescent depression. With the goal of generating new, testable hypotheses within a developmental affective neuroscience framework, we critically review findings and suggest future directions. Peer-reviewed empirical papers for inclusion in this critical review were obtained by searching PubMed, PsycInfo, and ScienceDirect for the years 1990–2010. Results A pattern of low striatal response and high medial prefrontal response to reward is evident in adolescents and adults with depression. Given the salience of social stimuli for positive affect and depression, reward function might be especially disrupted in response to social rewards. Because of changes in the dopamine system and reward function with aging, altered reward function in depression might be more evident during adolescence than later in life; however, low reward function may also be a stable characteristic of people who experience depression. Mechanisms of altered reward function in depression could include disrupted balance of corticostriatal circuit function, with disruption occurring as aberrant adolescent brain development. Conclusions Future studies should examine responses to social rewards; employ longitudinal and prospective designs; and investigate patterns of functional connectivity in reward circuits. Understanding altered reward function in depression has potential implications for treatment development. A more rigorous approach to investigating anhedonia, threat-reward interactions, and comorbid anxiety will be valuable to future progress in describing the role of reward function in the pathophysiology of depression. PMID:22117893
Optimal Linking Design for Response Model Parameters

ERIC Educational Resources Information Center

Barrett, Michelle D.; van der Linden, Wim J.

2017-01-01

Linking functions adjust for differences between identifiability restrictions used in different instances of the estimation of item response model parameters. These adjustments are necessary when results from those instances are to be compared. As linking functions are derived from estimated item response model parameters, parameter estimation…
Daily Spouse Responsiveness Predicts Longer-Term Trajectories of Physical Function

PubMed Central

Wilson, Stephanie J.; Martire, Lynn M.; Sliwinski, Martin J.

2017-01-01

Everyday interpersonal experiences may underlie the well-established link between close relationships and physical health, but multitemporal designs necessary for strong conclusions about temporal sequence are rare. The current study of 145 knee osteoarthritis patients and their spouses focused on a novel pattern in everyday interactions, daily spouse responsiveness—the degree to which spouse responses are calibrated to changes in patients’ everyday verbal pain expression. Using couple-level slopes, multilevel latent-variable growth models tested associations between three types of daily spouse responsiveness (empathic, solicitous, and punishing), as measured during a 3-week experience-sampling study, and change in patient physical function across 18 months. As predicted, patients whose spouses were more empathically responsive to their pain expression showed better physical function over time compared to those whose spouses were less empathically responsive. This study points to daily responsiveness, a theoretically rooted operationalization of spouse sensitivity, as important for long-term changes in objective physical function. PMID:28459650
Comparison of Spontaneously Elicited Language Patterns in Specific Language Impairment and High-Functioning Autism.

PubMed

Craig, Megan; Trauner, Doris

2018-02-01

We aimed to characterize differences in the use of language in children with specific language impairment and high-functioning autism by analyzing verbal responses on standardized tests. The overall goal was to provide clinicians with additional tools with which to aid in distinguishing the two neurodevelopmental disorders. This study included 16 children with specific language impairment, 28 children with high-functioning autism, and 52 typically developing participants between the ages of six and 14. Groups were matched for age, and specific language impairment and high-functioning autism groups were matched on verbal and performance IQ. Responses from standardized tests were examined for response length, grammatical errors, filler words, perseverations, revisions (repeated attempts to begin or continue a sentence), off-topic attention shifts (lapses in attention to the task), and rambling. Data were analyzed using parametric and nonparametric methods. Specific language impairment responses were longer and contained more filler words than did those of the other two groups, whereas high-functioning autism responses exhibited more grammatical errors, off-topic attention shifts, and rambling. Specific language impairment and high-functioning autism responses showed higher rates of perseveration compared with controls. There were no significant differences in revisions among the three groups. Differences in language patterns of participants with specific language impairment and high-functioning autism may be useful to the clinician in helping to differentiate isolated language impairment from high-functioning autism. The results also support the conclusion that the two conditions are separable, and each exhibits a different pattern of language dysfunction. Copyright © 2017 Elsevier Inc. All rights reserved.
A predator-prey model with generic birth and death rates for the predator.

PubMed

Terry, Alan J

2014-02-01

We propose and study a predator-prey model in which the predator has a Holling type II functional response and generic per capita birth and death rates. Given that prey consumption provides the energy for predator activity, and that the predator functional response represents the prey consumption rate per predator, we assume that the per capita birth and death rates for the predator are, respectively, increasing and decreasing functions of the predator functional response. These functions are monotonic, but not necessarily strictly monotonic, for all values of the argument. In particular, we allow the possibility that the predator birth rate is zero for all sufficiently small values of the predator functional response, reflecting the idea that a certain level of energy intake is needed before a predator can reproduce. Our analysis reveals that the model exhibits the behaviours typically found in predator-prey models - extinction of the predator population, convergence to a periodic orbit, or convergence to a co-existence fixed point. For a specific example, in which the predator birth and death rates are constant for all sufficiently small or large values of the predator functional response, we corroborate our analysis with numerical simulations. In the unlikely case where these birth and death rates equal the same constant for all sufficiently large values of the predator functional response, the model is capable of structurally unstable behaviour, with a small change in the initial conditions leading to a more pronounced change in the long-term dynamics. Copyright © 2013 Elsevier Inc. All rights reserved.
Dopamine reward prediction error responses reflect marginal utility.

PubMed

Stauffer, William R; Lak, Armin; Schultz, Wolfram

2014-11-03

Optimal choices require an accurate neuronal representation of economic value. In economics, utility functions are mathematical representations of subjective value that can be constructed from choices under risk. Utility usually exhibits a nonlinear relationship to physical reward value that corresponds to risk attitudes and reflects the increasing or decreasing marginal utility obtained with each additional unit of reward. Accordingly, neuronal reward responses coding utility should robustly reflect this nonlinearity. In two monkeys, we measured utility as a function of physical reward value from meaningful choices under risk (that adhered to first- and second-order stochastic dominance). The resulting nonlinear utility functions predicted the certainty equivalents for new gambles, indicating that the functions' shapes were meaningful. The monkeys were risk seeking (convex utility function) for low reward and risk avoiding (concave utility function) with higher amounts. Critically, the dopamine prediction error responses at the time of reward itself reflected the nonlinear utility functions measured at the time of choices. In particular, the reward response magnitude depended on the first derivative of the utility function and thus reflected the marginal utility. Furthermore, dopamine responses recorded outside of the task reflected the marginal utility of unpredicted reward. Accordingly, these responses were sufficient to train reinforcement learning models to predict the behaviorally defined expected utility of gambles. These data suggest a neuronal manifestation of marginal utility in dopamine neurons and indicate a common neuronal basis for fundamental explanatory constructs in animal learning theory (prediction error) and economic decision theory (marginal utility). Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.
PreSMA stimulation changes task-free functional connectivity in the fronto-basal-ganglia that correlates with response inhibition efficiency

PubMed Central

Xu, Benjamin; Sandrini, Marco; Wang, Wen-tung; Smith, Jason F.; Sarlls, Joelle E.; Awosika, Oluwole; Butman, John A.; Horwitz, Barry; Cohen, Leonardo G.

2016-01-01

Previous work using transcranial magnetic stimulation (TMS) demonstrated that the right pre-supplementary motor area (preSMA), a node in the fronto-basal-ganglia network, is critical for response inhibition. However, TMS influences interconnected regions, raising the possibility of a link between the preSMA activity and the functional connectivity within the network. To understand this relationship, we applied single-pulse TMS to the right preSMA during functional magnetic resonance imaging when the subjects were at rest to examine changes in neural activity and functional connectivity within the network in relation to the efficiency of response inhibition evaluated with a stop-signal task. The results showed that preSMA-TMS increased activation in the right inferior-frontal cortex (rIFC) and basal ganglia and modulated their task-free functional connectivity. Both the TMS-induced changes in the basal-ganglia activation and the functional connectivity between rIFC and left striatum, and of the overall network correlated with the efficiency of response inhibition and with the white-matter microstructure along the preSMA – rIFC pathway. These results suggest that the task-free functional and structural connectivity between the rIFCop and basal ganglia are critical to the efficiency of response inhibition. PMID:27144466
A Study of Morrison's Iterative Noise Removal Method. Final Report M. S. Thesis

NASA Technical Reports Server (NTRS)

Ioup, G. E.; Wright, K. A. R.

1985-01-01

Morrison's iterative noise removal method is studied by characterizing its effect upon systems of differing noise level and response function. The nature of data acquired from a linear shift invariant instrument is discussed so as to define the relationship between the input signal, the instrument response function, and the output signal. Fourier analysis is introduced, along with several pertinent theorems, as a tool to more thorough understanding of the nature of and difficulties with deconvolution. In relation to such difficulties the necessity of a noise removal process is discussed. Morrison's iterative noise removal method and the restrictions upon its application are developed. The nature of permissible response functions is discussed, as is the choice of the response functions used.
Functional neural networks underlying response inhibition in adolescents and adults.

PubMed

Stevens, Michael C; Kiehl, Kent A; Pearlson, Godfrey D; Calhoun, Vince D

2007-07-19

This study provides the first description of neural network dynamics associated with response inhibition in healthy adolescents and adults. Functional and effective connectivity analyses of whole brain hemodynamic activity elicited during performance of a Go/No-Go task were used to identify functionally integrated neural networks and characterize their causal interactions. Three response inhibition circuits formed a hierarchical, inter-dependent system wherein thalamic modulation of input to premotor cortex by fronto-striatal regions led to response suppression. Adolescents differed from adults in the degree of network engagement, regional fronto-striatal-thalamic connectivity, and network dynamics. We identify and characterize several age-related differences in the function of neural circuits that are associated with behavioral performance changes across adolescent development.
Improving traditional balancing methods for high-speed rotors

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

Ling, J.; Cao, Y.

1996-01-01

This paper introduces frequency response functions, analyzes the relationships between the frequency response functions and influence coefficients theoretically, and derives corresponding mathematical equations for high-speed rotor balancing. The relationships between the imbalance masses on the rotor and frequency response functions are also analyzed based upon the modal balancing method, and the equations related to the static and dynamic imbalance masses and the frequency response function are obtained. Experiments on a high-speed rotor balancing rig were performed to verify the theory, and the experimental data agree satisfactorily with the analytical solutions. The improvement on the traditional balancing method proposed in thismore » paper will substantially reduce the number of rotor startups required during the balancing process of rotating machinery.« less
Functional neural networks underlying response inhibition in adolescents and adults

PubMed Central

Stevens, Michael C.; Kiehl, Kent A.; Pearlson, Godfrey D.; Calhoun, Vince D.

2008-01-01

This study provides the first description of neural network dynamics associated with response inhibition in healthy adolescents and adults. Functional and effective connectivity analyses of whole brain hemodynamic activity elicited during performance of a Go/No-Go task were used to identify functionally-integrated neural networks and characterize their causal interactions. Three response inhibition circuits formed a hierarchical, inter-dependent system wherein thalamic modulation of input to premotor cortex by frontostriatal regions led to response suppression. Adolescents differed from adults in the degree of network engagement, regional fronto-striatal-thalamic connectivity, and network dynamics. We identify and characterize several age-related differences in the function of neural circuits that are associated with behavioral performance changes across adolescent development. PMID:17467816
25 CFR 12.1 - Who is responsible for the Bureau of Indian Affairs law enforcement function?

Code of Federal Regulations, 2011 CFR

2011-04-01

... 25 Indians 1 2011-04-01 2011-04-01 false Who is responsible for the Bureau of Indian Affairs law enforcement function? 12.1 Section 12.1 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER INDIAN COUNTRY LAW ENFORCEMENT Responsibilities § 12.1 Who is responsible for the Bureau of Indian...
25 CFR 12.1 - Who is responsible for the Bureau of Indian Affairs law enforcement function?

Code of Federal Regulations, 2012 CFR

2012-04-01

... 25 Indians 1 2012-04-01 2011-04-01 true Who is responsible for the Bureau of Indian Affairs law enforcement function? 12.1 Section 12.1 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER INDIAN COUNTRY LAW ENFORCEMENT Responsibilities § 12.1 Who is responsible for the Bureau of Indian...
25 CFR 12.1 - Who is responsible for the Bureau of Indian Affairs law enforcement function?

Code of Federal Regulations, 2013 CFR

2013-04-01

... 25 Indians 1 2013-04-01 2013-04-01 false Who is responsible for the Bureau of Indian Affairs law enforcement function? 12.1 Section 12.1 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER INDIAN COUNTRY LAW ENFORCEMENT Responsibilities § 12.1 Who is responsible for the Bureau of Indian...
25 CFR 12.1 - Who is responsible for the Bureau of Indian Affairs law enforcement function?

Code of Federal Regulations, 2014 CFR

2014-04-01

... 25 Indians 1 2014-04-01 2014-04-01 false Who is responsible for the Bureau of Indian Affairs law enforcement function? 12.1 Section 12.1 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER INDIAN COUNTRY LAW ENFORCEMENT Responsibilities § 12.1 Who is responsible for the Bureau of Indian...
Systems analysis of transcriptome data provides new hypotheses about Arabidopsis root response to nitrate treatments

PubMed Central

Canales, Javier; Moyano, Tomás C.; Villarroel, Eva; Gutiérrez, Rodrigo A.

2014-01-01

Nitrogen (N) is an essential macronutrient for plant growth and development. Plants adapt to changes in N availability partly by changes in global gene expression. We integrated publicly available root microarray data under contrasting nitrate conditions to identify new genes and functions important for adaptive nitrate responses in Arabidopsis thaliana roots. Overall, more than 2000 genes exhibited changes in expression in response to nitrate treatments in Arabidopsis thaliana root organs. Global regulation of gene expression by nitrate depends largely on the experimental context. However, despite significant differences from experiment to experiment in the identity of regulated genes, there is a robust nitrate response of specific biological functions. Integrative gene network analysis uncovered relationships between nitrate-responsive genes and 11 highly co-expressed gene clusters (modules). Four of these gene network modules have robust nitrate responsive functions such as transport, signaling, and metabolism. Network analysis hypothesized G2-like transcription factors are key regulatory factors controlling transport and signaling functions. Our meta-analysis highlights the role of biological processes not studied before in the context of the nitrate response such as root hair development and provides testable hypothesis to advance our understanding of nitrate responses in plants. PMID:24570678
Predator functional response and prey survival: Direct and indirect interactions affecting a marked prey population

USGS Publications Warehouse

Miller, David A.; Grand, J.B.; Fondell, T.F.; Anthony, M.

2006-01-01

1. Predation plays an integral role in many community interactions, with the number of predators and the rate at which they consume prey (i.e. their functional response) determining interaction strengths. Owing to the difficulty of directly observing predation events, attempts to determine the functional response of predators in natural systems are limited. Determining the forms that predator functional responses take in complex systems is important in advancing understanding of community interactions. 2. Prey survival has a direct relationship to the functional response of their predators. We employed this relationship to estimate the functional response for bald eagle Haliaeetus leucocepalus predation of Canada goose Branta canadensis nests. We compared models that incorporated eagle abundance, nest abundance and alternative prey presence to determine the form of the functional response that best predicted intra-annual variation in survival of goose nests. 3. Eagle abundance, nest abundance and the availability of alternative prey were all related to predation rates of goose nests by eagles. There was a sigmoidal relationship between predation rate and prey abundance and prey switching occurred when alternative prey was present. In addition, predation by individual eagles increased as eagle abundance increased. 4. A complex set of interactions among the three species examined in this study determined survival rates of goose nests. Results show that eagle predation had both prey- and predator-dependent components with no support for ratio dependence. In addition, indirect interactions resulting from the availability of alternative prey had an important role in mediating the rate at which eagles depredated nests. As a result, much of the within-season variation in nest survival was due to changing availability of alternative prey consumed by eagles. 5. Empirical relationships drawn from ecological theory can be directly integrated into the estimation process to determine the mechanisms responsible for variation in observed survival rates. The relationship between predator functional response and prey survival offers a flexible and robust method to advance our understanding of predator-prey interactions in many complex natural systems where prey populations are marked and regularly visited. ?? 2006 British Ecological Society.
Functional Additive Mixed Models

PubMed Central

Scheipl, Fabian; Staicu, Ana-Maria; Greven, Sonja

2014-01-01

We propose an extensive framework for additive regression models for correlated functional responses, allowing for multiple partially nested or crossed functional random effects with flexible correlation structures for, e.g., spatial, temporal, or longitudinal functional data. Additionally, our framework includes linear and nonlinear effects of functional and scalar covariates that may vary smoothly over the index of the functional response. It accommodates densely or sparsely observed functional responses and predictors which may be observed with additional error and includes both spline-based and functional principal component-based terms. Estimation and inference in this framework is based on standard additive mixed models, allowing us to take advantage of established methods and robust, flexible algorithms. We provide easy-to-use open source software in the pffr() function for the R-package refund. Simulations show that the proposed method recovers relevant effects reliably, handles small sample sizes well and also scales to larger data sets. Applications with spatially and longitudinally observed functional data demonstrate the flexibility in modeling and interpretability of results of our approach. PMID:26347592
Functional Additive Mixed Models.

PubMed

Scheipl, Fabian; Staicu, Ana-Maria; Greven, Sonja

2015-04-01

We propose an extensive framework for additive regression models for correlated functional responses, allowing for multiple partially nested or crossed functional random effects with flexible correlation structures for, e.g., spatial, temporal, or longitudinal functional data. Additionally, our framework includes linear and nonlinear effects of functional and scalar covariates that may vary smoothly over the index of the functional response. It accommodates densely or sparsely observed functional responses and predictors which may be observed with additional error and includes both spline-based and functional principal component-based terms. Estimation and inference in this framework is based on standard additive mixed models, allowing us to take advantage of established methods and robust, flexible algorithms. We provide easy-to-use open source software in the pffr() function for the R-package refund. Simulations show that the proposed method recovers relevant effects reliably, handles small sample sizes well and also scales to larger data sets. Applications with spatially and longitudinally observed functional data demonstrate the flexibility in modeling and interpretability of results of our approach.

A Functional Varying-Coefficient Single-Index Model for Functional Response Data

PubMed Central

Li, Jialiang; Huang, Chao; Zhu, Hongtu

2016-01-01

Motivated by the analysis of imaging data, we propose a novel functional varying-coefficient single index model (FVCSIM) to carry out the regression analysis of functional response data on a set of covariates of interest. FVCSIM represents a new extension of varying-coefficient single index models for scalar responses collected from cross-sectional and longitudinal studies. An efficient estimation procedure is developed to iteratively estimate varying coefficient functions, link functions, index parameter vectors, and the covariance function of individual functions. We systematically examine the asymptotic properties of all estimators including the weak convergence of the estimated varying coefficient functions, the asymptotic distribution of the estimated index parameter vectors, and the uniform convergence rate of the estimated covariance function and their spectrum. Simulation studies are carried out to assess the finite-sample performance of the proposed procedure. We apply FVCSIM to investigating the development of white matter diffusivities along the corpus callosum skeleton obtained from Alzheimer’s Disease Neuroimaging Initiative (ADNI) study. PMID:29200540
A Functional Varying-Coefficient Single-Index Model for Functional Response Data.

PubMed

Li, Jialiang; Huang, Chao; Zhu, Hongtu

2017-01-01

Motivated by the analysis of imaging data, we propose a novel functional varying-coefficient single index model (FVCSIM) to carry out the regression analysis of functional response data on a set of covariates of interest. FVCSIM represents a new extension of varying-coefficient single index models for scalar responses collected from cross-sectional and longitudinal studies. An efficient estimation procedure is developed to iteratively estimate varying coefficient functions, link functions, index parameter vectors, and the covariance function of individual functions. We systematically examine the asymptotic properties of all estimators including the weak convergence of the estimated varying coefficient functions, the asymptotic distribution of the estimated index parameter vectors, and the uniform convergence rate of the estimated covariance function and their spectrum. Simulation studies are carried out to assess the finite-sample performance of the proposed procedure. We apply FVCSIM to investigating the development of white matter diffusivities along the corpus callosum skeleton obtained from Alzheimer's Disease Neuroimaging Initiative (ADNI) study.
Nature-inspired multifunctional membrane fabricated by adaptive hybridization of PNIPAm and PPy

NASA Astrophysics Data System (ADS)

Kim, Hyejeong; Kim, Kiwoong; Lee, Sang Joon

2017-11-01

Specialized plant organs, such as guard cells of stomata, consist of soft materials with deformability and electrochemical properties in response to various environmental stimuli. Stimulus-responsive hydrogels with electrochemical properties are good candidates for imitating such functionalities having great potential in a wide range of applications. However, conductive hydrogels are usually mechanically rigid and the fabrication technology of structured hydrogels has low reproducibility. Here, inspired by stimulus-responsive functionalities of plants, a thermo-responsive multifunctional hybrid membrane (HM) is synthesized through the in situ hybridization of conductive poly(pyrrole)(PPy) on a photopolymerized poly(N-isopropylacrylamide)(PNIPAm) membrane. The various properties of the HM are investigated to characterize its multiple functions. In terms of morphology, the HM can be easily fabricated into various structures, and exhibits thermo-responsive deformability. In terms of functionality, it exhibits various electrical and charge responses to thermal stimuli. This simple and efficient fabrication method can be used as a promising platform for fabricating a variety of functional devices, such as actuators, biosensors, and filtration membranes. This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korean government (MSIP) (No. 2017R1A2B3005415).
Dopamine Reward Prediction Error Responses Reflect Marginal Utility

PubMed Central

Stauffer, William R.; Lak, Armin; Schultz, Wolfram

2014-01-01

Summary Background Optimal choices require an accurate neuronal representation of economic value. In economics, utility functions are mathematical representations of subjective value that can be constructed from choices under risk. Utility usually exhibits a nonlinear relationship to physical reward value that corresponds to risk attitudes and reflects the increasing or decreasing marginal utility obtained with each additional unit of reward. Accordingly, neuronal reward responses coding utility should robustly reflect this nonlinearity. Results In two monkeys, we measured utility as a function of physical reward value from meaningful choices under risk (that adhered to first- and second-order stochastic dominance). The resulting nonlinear utility functions predicted the certainty equivalents for new gambles, indicating that the functions’ shapes were meaningful. The monkeys were risk seeking (convex utility function) for low reward and risk avoiding (concave utility function) with higher amounts. Critically, the dopamine prediction error responses at the time of reward itself reflected the nonlinear utility functions measured at the time of choices. In particular, the reward response magnitude depended on the first derivative of the utility function and thus reflected the marginal utility. Furthermore, dopamine responses recorded outside of the task reflected the marginal utility of unpredicted reward. Accordingly, these responses were sufficient to train reinforcement learning models to predict the behaviorally defined expected utility of gambles. Conclusions These data suggest a neuronal manifestation of marginal utility in dopamine neurons and indicate a common neuronal basis for fundamental explanatory constructs in animal learning theory (prediction error) and economic decision theory (marginal utility). PMID:25283778
Taxonomic and Functional Responses to Fire and Post-Fire Management of a Mediterranean Hymenoptera Community

NASA Astrophysics Data System (ADS)

Mateos, Eduardo; Santos, Xavier; Pujade-Villar, Juli

2011-11-01

Fire is one of the commonest disturbances worldwide, transforming habitat structure and affecting ecosystem functioning. Understanding how species respond to such environmental disturbances is a major conservation goal that should be monitored using functionally and taxonomically diverse groups such as Hymenoptera. In this respect, we have analyzed the taxonomic and functional response to fire and post-fire management of a Hymenoptera community from a Mediterranean protected area. Thus, Hymenoptera were sampled at fifteen sites located in three burnt areas submitted to different post-fire practices, as well as at five sites located in peripheral unburnt pine forest. A total of 4882 specimens belonging to 33 families, which were classified into six feeding groups according to their dietary preferences, were collected. ANOVA and Redundancy Analyses showed a taxonomic and functional response to fire as all burnt areas had more Hymenoptera families, different community composition and higher numbers of parasitoids than the unburnt area. Taxonomic differences were also found between burnt areas in terms of the response of Hymenoptera to post-fire management. In general the number of parasitoids was positively correlated to the number of potential host arthropods. Parasitoids are recognized to be sensitive to habitat changes, thus highlighting their value for monitoring the functional responses of organisms to habitat disturbance. The taxonomic and functional responses of Hymenoptera suggest that some pine-forest fires can enhance habitat heterogeneity and arthropod diversity, hence increasing interspecific interactions such as those established by parasitoids and their hosts.
Taxonomic and functional responses to fire and post-fire management of a Mediterranean hymenoptera community.

PubMed

Mateos, Eduardo; Santos, Xavier; Pujade-Villar, Juli

2011-11-01

Fire is one of the commonest disturbances worldwide, transforming habitat structure and affecting ecosystem functioning. Understanding how species respond to such environmental disturbances is a major conservation goal that should be monitored using functionally and taxonomically diverse groups such as Hymenoptera. In this respect, we have analyzed the taxonomic and functional response to fire and post-fire management of a Hymenoptera community from a Mediterranean protected area. Thus, Hymenoptera were sampled at fifteen sites located in three burnt areas submitted to different post-fire practices, as well as at five sites located in peripheral unburnt pine forest. A total of 4882 specimens belonging to 33 families, which were classified into six feeding groups according to their dietary preferences, were collected. ANOVA and Redundancy Analyses showed a taxonomic and functional response to fire as all burnt areas had more Hymenoptera families, different community composition and higher numbers of parasitoids than the unburnt area. Taxonomic differences were also found between burnt areas in terms of the response of Hymenoptera to post-fire management. In general the number of parasitoids was positively correlated to the number of potential host arthropods. Parasitoids are recognized to be sensitive to habitat changes, thus highlighting their value for monitoring the functional responses of organisms to habitat disturbance. The taxonomic and functional responses of Hymenoptera suggest that some pine-forest fires can enhance habitat heterogeneity and arthropod diversity, hence increasing interspecific interactions such as those established by parasitoids and their hosts.
A trust region-based approach to optimize triple response systems

NASA Astrophysics Data System (ADS)

Fan, Shu-Kai S.; Fan, Chihhao; Huang, Chia-Fen

2014-05-01

This article presents a new computing procedure for the global optimization of the triple response system (TRS) where the response functions are non-convex quadratics and the input factors satisfy a radial constrained region of interest. The TRS arising from response surface modelling can be approximated using a nonlinear mathematical program that considers one primary objective function and two secondary constraint functions. An optimization algorithm named the triple response surface algorithm (TRSALG) is proposed to determine the global optimum for the non-degenerate TRS. In TRSALG, the Lagrange multipliers of the secondary functions are determined using the Hooke-Jeeves search method and the Lagrange multiplier of the radial constraint is located using the trust region method within the global optimality space. The proposed algorithm is illustrated in terms of three examples appearing in the quality-control literature. The results of TRSALG compared to a gradient-based method are also presented.
Estradiol selectively enhances auditory function in avian forebrain neurons

PubMed Central

Caras, Melissa L.; O’Brien, Matthew; Brenowitz, Eliot A.; Rubel, Edwin W

2012-01-01

Sex steroids modulate vertebrate sensory processing, but the impact of circulating hormone levels on forebrain function remains unclear. We tested the hypothesis that circulating sex steroids modulate single-unit responses in the avian telencephalic auditory nucleus, field L. We mimicked breeding or non-breeding conditions by manipulating plasma 17β-estradiol levels in wild-caught female Gambel’s white-crowned sparrows (Zonotrichia leucophrys gambelii). Extracellular responses of single neurons to tones and conspecific songs presented over a range of intensities revealed that estradiol selectively enhanced auditory function in cells that exhibited monotonic rate-level functions to pure tones. In these cells, estradiol treatment increased spontaneous and maximum evoked firing rates, increased pure tone response strengths and sensitivity, and expanded the range of intensities over which conspecific song stimuli elicited significant responses. Estradiol did not significantly alter the sensitivity or dynamic ranges of cells that exhibited non-monotonic rate-level functions. Notably, there was a robust correlation between plasma estradiol concentrations in individual birds and physiological response properties in monotonic, but not non-monotonic neurons. These findings demonstrate that functionally distinct classes of anatomically overlapping forebrain neurons are differentially regulated by sex steroid hormones in a dose-dependent manner. PMID:23223283
17 CFR 200.12 - Functional responsibilities.

Code of Federal Regulations, 2011 CFR

2011-04-01

... ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Organization and Program Management General Organization § 200.12 Functional responsibilities. This section sets forth the administrative and substantive...
Excited-state absorption in tetrapyridyl porphyrins: comparing real-time and quadratic-response time-dependent density functional theory

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

Bowman, David N.; Asher, Jason C.; Fischer, Sean A.

2017-01-01

Threemeso-substituted tetrapyridyl porphyrins (free base, Ni(ii), and Cu(ii)) were investigated for their optical limiting (OL) capabilities using real-time (RT-), linear-response (LR-), and quadratic-response (QR-) time-dependent density functional theory (TDDFT) methods.
Linear response to nonstationary random excitation.

NASA Technical Reports Server (NTRS)

Hasselman, T.

1972-01-01

Development of a method for computing the mean-square response of linear systems to nonstationary random excitation of the form given by y(t) = f(t) x(t), in which x(t) = a stationary process and f(t) is deterministic. The method is suitable for application to multidegree-of-freedom systems when the mean-square response at a point due to excitation applied at another point is desired. Both the stationary process, x(t), and the modulating function, f(t), may be arbitrary. The method utilizes a fundamental component of transient response dependent only on x(t) and the system, and independent of f(t) to synthesize the total response. The role played by this component is analogous to that played by the Green's function or impulse response function in the convolution integral.
Modeling Rabbit Responses to Single and Multiple Aerosol ...

EPA Pesticide Factsheets

Journal Article Survival models are developed here to predict response and time-to-response for mortality in rabbits following exposures to single or multiple aerosol doses of Bacillus anthracis spores. Hazard function models were developed for a multiple dose dataset to predict the probability of death through specifying dose-response functions and the time between exposure and the time-to-death (TTD). Among the models developed, the best-fitting survival model (baseline model) has an exponential dose-response model with a Weibull TTD distribution. Alternative models assessed employ different underlying dose-response functions and use the assumption that, in a multiple dose scenario, earlier doses affect the hazard functions of each subsequent dose. In addition, published mechanistic models are analyzed and compared with models developed in this paper. None of the alternative models that were assessed provided a statistically significant improvement in fit over the baseline model. The general approach utilizes simple empirical data analysis to develop parsimonious models with limited reliance on mechanistic assumptions. The baseline model predicts TTDs consistent with reported results from three independent high-dose rabbit datasets. More accurate survival models depend upon future development of dose-response datasets specifically designed to assess potential multiple dose effects on response and time-to-response. The process used in this paper to dev
Generation of the neutron response function of an NE213 scintillator for fusion applications

NASA Astrophysics Data System (ADS)

Binda, F.; Eriksson, J.; Ericsson, G.; Hellesen, C.; Conroy, S.; Nocente, M.; Sundén, E. Andersson; JET Contributors

2017-09-01

In this work we present a method to evaluate the neutron response function of an NE213 liquid scintillator. This method is particularly useful when the proton light yield function of the detector has not been measured, since it is based on a proton light yield function taken from literature, MCNPX simulations, measurements of gamma-rays from a calibration source and measurements of neutrons from fusion experiments with ohmic plasmas. The inclusion of the latter improves the description of the proton light yield function in the energy range of interest (around 2.46 MeV). We apply this method to an NE213 detector installed at JET, inside the radiation shielding of the magnetic proton recoil (MPRu) spectrometer, and present the results from the calibration along with some examples of application of the response function to perform neutron emission spectroscopy (NES) of fusion plasmas. We also investigate how the choice of the proton light yield function affects the NES analysis, finding that the result does not change significantly. This points to the fact that the method for the evaluation of the neutron response function is robust and gives reliable results.
Image Processing, Coding, and Compression with Multiple-Point Impulse Response Functions.

NASA Astrophysics Data System (ADS)

Stossel, Bryan Joseph

1995-01-01

Aspects of image processing, coding, and compression with multiple-point impulse response functions are investigated. Topics considered include characterization of the corresponding random-walk transfer function, image recovery for images degraded by the multiple-point impulse response, and the application of the blur function to image coding and compression. It is found that although the zeros of the real and imaginary parts of the random-walk transfer function occur in continuous, closed contours, the zeros of the transfer function occur at isolated spatial frequencies. Theoretical calculations of the average number of zeros per area are in excellent agreement with experimental results obtained from computer counts of the zeros. The average number of zeros per area is proportional to the standard deviations of the real part of the transfer function as well as the first partial derivatives. Statistical parameters of the transfer function are calculated including the mean, variance, and correlation functions for the real and imaginary parts of the transfer function and their corresponding first partial derivatives. These calculations verify the assumptions required in the derivation of the expression for the average number of zeros. Interesting results are found for the correlations of the real and imaginary parts of the transfer function and their first partial derivatives. The isolated nature of the zeros in the transfer function and its characteristics at high spatial frequencies result in largely reduced reconstruction artifacts and excellent reconstructions are obtained for distributions of impulses consisting of 25 to 150 impulses. The multiple-point impulse response obscures original scenes beyond recognition. This property is important for secure transmission of data on many communication systems. The multiple-point impulse response enables the decoding and restoration of the original scene with very little distortion. Images prefiltered by the random-walk transfer function yield greater compression ratios than are obtained for the original scene. The multiple-point impulse response decreases the bit rate approximately 40-70% and affords near distortion-free reconstructions. Due to the lossy nature of transform-based compression algorithms, noise reduction measures must be incorporated to yield acceptable reconstructions after decompression.
42 CFR 421.201 - Performance criteria and standards.

Code of Federal Regulations, 2010 CFR

2010-10-01

... funds. (2) The standards evaluate the specific requirements of each functional responsibility or... performance of functional responsibilities such as— (i) Accurate and timely payment determinations; (ii...
Extension of applicable neutron energy of DARWIN up to 1 GeV.

PubMed

Satoh, D; Sato, T; Endo, A; Matsufuji, N; Takada, M

2007-01-01

The radiation-dose monitor, DARWIN, needs a set of response functions of the liquid organic scintillator to assess a neutron dose. SCINFUL-QMD is a Monte Carlo based computer code to evaluate the response functions. In order to improve the accuracy of the code, a new light-output function based on the experimental data was developed for the production and transport of protons deuterons, tritons, (3)He nuclei and alpha particles, and incorporated into the code. The applicable energy of DARWIN was extended to 1 GeV using the response functions calculated by the modified SCINFUL-QMD code.
32 CFR 352a.4 - Responsibilities and functions.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) ORGANIZATIONAL CHARTERS DEFENSE FINANCE AND ACCOUNTING SERVICE (DFAS) § 352a.4 Responsibilities and functions. (a) The Director, Defense Finance and Accounting Service (DFAS), is the principal DoD executive for finance and accounting requirements, systems, and functions identified in DoD Directive 5118.3, 1 and...
32 CFR 352a.4 - Responsibilities and functions.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) ORGANIZATIONAL CHARTERS DEFENSE FINANCE AND ACCOUNTING SERVICE (DFAS) § 352a.4 Responsibilities and functions. (a) The Director, Defense Finance and Accounting Service (DFAS), is the principal DoD executive for finance and accounting requirements, systems, and functions identified in DoD Directive 5118.3, 1 and...
32 CFR 352a.4 - Responsibilities and functions.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) ORGANIZATIONAL CHARTERS DEFENSE FINANCE AND ACCOUNTING SERVICE (DFAS) § 352a.4 Responsibilities and functions. (a) The Director, Defense Finance and Accounting Service (DFAS), is the principal DoD executive for finance and accounting requirements, systems, and functions identified in DoD Directive 5118.3, 1 and...
32 CFR 352a.4 - Responsibilities and functions.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) ORGANIZATIONAL CHARTERS DEFENSE FINANCE AND ACCOUNTING SERVICE (DFAS) § 352a.4 Responsibilities and functions. (a) The Director, Defense Finance and Accounting Service (DFAS), is the principal DoD executive for finance and accounting requirements, systems, and functions identified in DoD Directive 5118.3, 1 and...

32 CFR 352a.4 - Responsibilities and functions.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) ORGANIZATIONAL CHARTERS DEFENSE FINANCE AND ACCOUNTING SERVICE (DFAS) § 352a.4 Responsibilities and functions. (a) The Director, Defense Finance and Accounting Service (DFAS), is the principal DoD executive for finance and accounting requirements, systems, and functions identified in DoD Directive 5118.3, 1 and...
Public health professionals' perceptions toward provision of health protection in England: a survey of expectations of Primary Care Trusts and Health Protection Units in the delivery of health protection

PubMed Central

Cosford, Paul A; O'Mahony, Mary; Angell, Emma; Bickler, Graham; Crawshaw, Shirley; Glencross, Janet; Horsley, Stephen S; McCloskey, Brian; Puleston, Richard; Seare, Nichola; Tobin, Martin D

2006-01-01

Background Effective health protection requires systematised responses with clear accountabilities. In England, Primary Care Trusts and the Health Protection Agency both have statutory responsibilities for health protection. A Memorandum of Understanding identifies responsibilities of both parties, but there is a potential lack of clarity about responsibility for specific health protection functions. We aimed to investigate professionals' perceptions of responsibility for different health protection functions, to inform future guidance for, and organisation of, health protection in England. Methods We sent a postal questionnaire to all health protection professionals in England from the following groups: (a) Directors of Public Health in Primary Care Trusts; (b) Directors of Health Protection Units within the Health Protection Agency; (c) Directors of Public Health in Strategic Health Authorities and; (d) Regional Directors of the Health Protection Agency Results The response rate exceeded 70%. Variations in perceptions of who should be, and who is, delivering health protection functions were observed within, and between, the professional groups (a)-(d). Concordance in views of which organisation should, and which does deliver was high (≥90%) for 6 of 18 health protection functions, but much lower (≤80%) for 6 other functions, including managing the implications of a case of meningitis out of hours, of landfill environmental contamination, vaccination in response to mumps outbreaks, nursing home infection control, monitoring sexually transmitted infections and immunisation training for primary care staff. The proportion of respondents reporting that they felt confident most or all of the time in the safe delivery of a health protection function was strongly correlated with the concordance (r = 0.65, P = 0.0038). Conclusion Whilst we studied professionals' perceptions, rather than actual responses to incidents, our study suggests that there are important areas of health protection where consistent understanding of responsibility for delivery is lacking. There are opportunities to clarify the responsibility for health protection in England, perhaps learning from the approaches used for those health protection functions where we found consistent perceptions of accountability. PMID:17156421
Public health professionals' perceptions toward provision of health protection in England: a survey of expectations of Primary Care Trusts and Health Protection Units in the delivery of health protection.

PubMed

Cosford, Paul A; O'Mahony, Mary; Angell, Emma; Bickler, Graham; Crawshaw, Shirley; Glencross, Janet; Horsley, Stephen S; McCloskey, Brian; Puleston, Richard; Seare, Nichola; Tobin, Martin D

2006-12-07

Effective health protection requires systematised responses with clear accountabilities. In England, Primary Care Trusts and the Health Protection Agency both have statutory responsibilities for health protection. A Memorandum of Understanding identifies responsibilities of both parties, but there is a potential lack of clarity about responsibility for specific health protection functions. We aimed to investigate professionals' perceptions of responsibility for different health protection functions, to inform future guidance for, and organisation of, health protection in England. We sent a postal questionnaire to all health protection professionals in England from the following groups: (a) Directors of Public Health in Primary Care Trusts; (b) Directors of Health Protection Units within the Health Protection Agency; (c) Directors of Public Health in Strategic Health Authorities and; (d) Regional Directors of the Health Protection Agency The response rate exceeded 70%. Variations in perceptions of who should be, and who is, delivering health protection functions were observed within, and between, the professional groups (a)-(d). Concordance in views of which organisation should, and which does deliver was high (> or =90%) for 6 of 18 health protection functions, but much lower (< or =80%) for 6 other functions, including managing the implications of a case of meningitis out of hours, of landfill environmental contamination, vaccination in response to mumps outbreaks, nursing home infection control, monitoring sexually transmitted infections and immunisation training for primary care staff. The proportion of respondents reporting that they felt confident most or all of the time in the safe delivery of a health protection function was strongly correlated with the concordance (r = 0.65, P = 0.0038). Whilst we studied professionals' perceptions, rather than actual responses to incidents, our study suggests that there are important areas of health protection where consistent understanding of responsibility for delivery is lacking. There are opportunities to clarify the responsibility for health protection in England, perhaps learning from the approaches used for those health protection functions where we found consistent perceptions of accountability.
Directive and incentive functions of affective action consequences: an ideomotor approach.

PubMed

Eder, Andreas B; Rothermund, Klaus; De Houwer, Jan; Hommel, Bernhard

2015-07-01

Five experiments examined whether affective consequences become associated with the responses producing them and whether anticipations of positive and negative action outcomes influence action control differently. In a learning phase, one response produced pleasant and another response unpleasant visual effects. In a subsequent test phase, the same actions were carried out in response to a neutral feature of affective stimuli. Results showed that responses were faster when the irrelevant valence of the response cue matched the valence of the response outcome, but only when the responses still produced outcomes. These results suggest that affective action consequences have a directive function in that they facilitate the selection of the associated response over other responses, even when the response outcome is unpleasant (Experiment 4A). Results of another experiment showed that affective action consequences can also have an incentive function in that responses with pleasant outcomes are generally facilitated relative to responses with unpleasant outcomes. However, this motivational effect was seen only in a free-choice test (Experiment 5). The results suggest that behavioral impulses induced by ideomotor processes are constrained by the motivational evaluation of the anticipated action outcome. A model that integrates motivational factors into ideomotor theory is presented.
Predicting invasive species impacts: a community module functional response approach reveals context dependencies.

PubMed

Paterson, Rachel A; Dick, Jaimie T A; Pritchard, Daniel W; Ennis, Marilyn; Hatcher, Melanie J; Dunn, Alison M

2015-03-01

Predatory functional responses play integral roles in predator-prey dynamics, and their assessment promises greater understanding and prediction of the predatory impacts of invasive species. Other interspecific interactions, however, such as parasitism and higher-order predation, have the potential to modify predator-prey interactions and thus the predictive capability of the comparative functional response approach. We used a four-species community module (higher-order predator; focal native or invasive predators; parasites of focal predators; native prey) to compare the predatory functional responses of native Gammarus duebeni celticus and invasive Gammarus pulex amphipods towards three invertebrate prey species (Asellus aquaticus, Simulium spp., Baetis rhodani), thus, quantifying the context dependencies of parasitism and a higher-order fish predator on these functional responses. Our functional response experiments demonstrated that the invasive amphipod had a higher predatory impact (lower handling time) on two of three prey species, which reflects patterns of impact observed in the field. The community module also revealed that parasitism had context-dependent influences, for one prey species, with the potential to further reduce the predatory impact of the invasive amphipod or increase the predatory impact of the native amphipod in the presence of a higher-order fish predator. Partial consumption of prey was similar for both predators and occurred increasingly in the order A. aquaticus, Simulium spp. and B. rhodani. This was associated with increasing prey densities, but showed no context dependencies with parasitism or higher-order fish predator. This study supports the applicability of comparative functional responses as a tool to predict and assess invasive species impacts incorporating multiple context dependencies. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.
Increased sensory noise and not muscle weakness explains changes in non-stepping postural responses following stance perturbations in healthy elderly.

PubMed

Afschrift, Maarten; De Groote, Friedl; Verschueren, Sabine; Jonkers, Ilse

2018-01-01

The response to stance perturbations changes with age. The shift from an ankle to a hip strategy with increasing perturbation magnitude occurs at lower accelerations in older than in young adults. This strategy shift has been related to age-related changes in muscle and sensory function. However, the effect of isolated changes in muscle or sensory function on the responses following stance perturbations cannot be determined experimentally since changes in muscle and sensory function occur simultaneously. Therefore, we used predictive simulations to estimate the effect of isolated changes in (rates of change in) maximal joint torques, functional base of support, and sensory noise on the response to backward platform translations. To evaluate whether these modeled changes in muscle and sensory function could explain the observed changes in strategy; simulated postural responses with a torque-driven double inverted pendulum model controlled using optimal state feedback were compared to measured postural responses in ten healthy young and ten healthy older adults. The experimentally observed peak hip angle during the response was significantly larger (5°) and the functional base of support was smaller (0.04m) in the older than in the young adults but peak joint torques and rates of joint torque were similar during the recovery. The addition of noise to the sensed states in the predictive simulations could explain the observed increase in peak hip angle in the elderly, whereas changes in muscle function could not. Hence, our results suggest that strength training alone might be insufficient to improve postural control in elderly. Copyright © 2017 Elsevier B.V. All rights reserved.
Preserved MHC-II antigen processing and presentation function in chronic HCV infection

PubMed Central

DH, Canaday; CJ, Burant; L, Jones; H, Aung; L, Woc-Colburn; DD, Anthony

2010-01-01

Individuals with chronic HCV infection have impaired response to vaccine, though the etiology remains to be elucidated. Dendritic cells (DC) and monocytes (MN) provide antigen uptake, processing, presentation, and costimulatory functions necessary to achieve optimal immune responses. The integrity of antigen processing and presentation function within these antigen presenting cells (APC) in the setting of HCV infection has been unclear. We used a novel T cell hybridoma system that specifically measures MHC-II antigen processing and presentation function of human APC. Results demonstrate MHC-II antigen processing and presentation function is preserved in both myeloid DC (mDC) and MN in the peripheral blood of chronically HCV-infected individuals, and indicates that an alteration in this function does not likely underlie the defective HCV-infected host response to vaccination. PMID:21055734
OZONE-INDUCED RESPIRATORY SYMPTOMS: EXPOSURE-RESPONSE MODELS AND ASSOCIATION WITH LUNG FUNCTION

EPA Science Inventory

Ozone-induced respiratory symptoms are known to be functions of concentration, minute ventilation, and duration of exposure. The purposes of this study were to identify an exposure-response model for symptoms, to determine whether response was related to age, and to assess the re...
32 CFR 395.4 - Functions and responsibilities.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) ORGANIZATIONAL CHARTERS DEFENSE LEGAL SERVICES AGENCY § 395.4 Functions and responsibilities. The Director..., and other assigned organizations. (c) Provide technical support and assistance for development of the...
The ethological trap: functional and numerical responses of highly efficient invasive predators driving prey extinctions.

PubMed

Spencer, Ricky-John; Van Dyke, James U; Thompson, Michael B

2016-10-01

Ecological traps are threats to organisms, and exist in a range of biological systems. A subset of ecological trap theory is the "ethological trap," whereby behaviors canalized by past natural selection become traps when environments change rapidly. Invasive predators are major threats to imperiled species and their ability to exploit canalized behaviors of naive prey is particularly important for the establishment of the predator and the decline of the native prey. Our study uses ecological theory to demonstrate that invasive predator controls require shifts in management priorities. Total predation rate (i.e., total response) is the product of both the functional response and numerical response of predators to prey. Functional responses are the changes in the rate of prey consumption by individual predators, relative to prey abundance. Numerical responses are the aggregative rates of prey consumption by all predators relative to prey density, which change with predator density via reproduction or migration, in response to changes in prey density. Traditional invasive predator management methods focus on reducing predator populations, and thus manage for numerical responses. These management efforts fail to manage for functional responses, and may not eliminate impacts of highly efficient individual predators. We explore this problem by modeling the impacts of functional and numerical responses of invasive foxes depredating imperiled Australian turtle nests. Foxes exhibit exceptionally efficient functional responses. A single fox can destroy >95% of turtle nests in a nesting area, which eliminates juvenile recruitment. In this case, the ethological trap is the "Arribada" nesting strategy, an emergent behavior whereby most turtles in a population nest simultaneously in the same nesting grounds. Our models show that Arribada nesting events do not oversaturate foxes, and small numbers of foxes depredate all of the nests in a given Arribada. Widely scattering nests may reduce fox predation rates, but the long generation times of turtles combined with their rapid recent decline suggests that evolutionary responses in nesting strategy may be unlikely. Our study demonstrates that reducing populations of highly efficient invasive predators is insufficient for preserving native prey species. Instead, management must reduce individual predator efficiency, independent of reducing predator population size. © 2016 by the Ecological Society of America.
Measurements of the response function and the detection efficiency of an NE213 scintillator for neutrons between 20 and 65 MeV

NASA Astrophysics Data System (ADS)

Meigo, S.

1997-02-01

For neutrons 25, 30 and 65 MeV, the response functions and detection efficiencies of an NE213 liquid scintillator were measured. Quasi-monoenergetic neutrons produced by the 7Li(p,N 0.1) reaction were employed for the measurement and the absolute flux of incident neutrons was determined within 4% accuracy using a proton recoil telescope. Response functions and detection efficiencies calculated with the Monte Carlo codes, CECIL and SCINFUL, were compared with the measured data. It was found that response functions calculated with SCINFUL agreed better with experimental ones than those with CECIL, however, the deuteron light output used in SCINFUL was too low. The response functions calculated with a revised SCINFUL agreed with the experimental ones quite well even for the deuteron bump and peak due to the C(n,d 0) reaction. It was confirmed that the detection efficiencies calculated with the original and the revised SCINFULs agreed with the experimental data within the experimental error, while those with CECIL were about 20% higher in the energy region above 30 MeV.
Basilar-membrane responses to broadband noise modeled using linear filters with rational transfer functions.

PubMed

Recio-Spinoso, Alberto; Fan, Yun-Hui; Ruggero, Mario A

2011-05-01

Basilar-membrane responses to white Gaussian noise were recorded using laser velocimetry at basal sites of the chinchilla cochlea with characteristic frequencies near 10 kHz and first-order Wiener kernels were computed by cross correlation of the stimuli and the responses. The presence or absence of minimum-phase behavior was explored by fitting the kernels with discrete linear filters with rational transfer functions. Excellent fits to the kernels were obtained with filters with transfer functions including zeroes located outside the unit circle, implying nonminimum-phase behavior. These filters accurately predicted basilar-membrane responses to other noise stimuli presented at the same level as the stimulus for the kernel computation. Fits with all-pole and other minimum-phase discrete filters were inferior to fits with nonminimum-phase filters. Minimum-phase functions predicted from the amplitude functions of the Wiener kernels by Hilbert transforms were different from the measured phase curves. These results, which suggest that basilar-membrane responses do not have the minimum-phase property, challenge the validity of models of cochlear processing, which incorporate minimum-phase behavior. © 2011 IEEE
Functional diversity of benthic ciliate communities in response to environmental gradients in a wetland of Yangtze Estuary, China.

PubMed

Xu, Yuan; Fan, Xinpeng; Warren, Alan; Zhang, Liquan; Xu, Henglong

2018-02-01

Researches on the functional diversity of benthic ecosystems have mainly focused on macrofauna, and studies on functional structure of ciliate communities have been based only on trophic- or size-groups. Current research was carried out on the changing patterns of classical and functional diversity of benthic ciliates in response to environmental gradients at three sites in a wetland in Yangtze Estuary. The results showed that changes of environmental factors (e.g. salinity, sediment grain size and hydrodynamic conditions) in the Yangtze Estuary induce variability in species composition and functional trait distribution. Furthermore, increased species richness and diversity did not lead to significant changes in functional diversity due to functional redundancy. However, salt water intrusion of Yangtze Estuary during the dry season could cause reduced functional diversity of ciliate communities. Current study provides the first insight into the functional diversity of ciliate communities in response to environmental gradients. Copyright © 2018 Elsevier Ltd. All rights reserved.
Altered neural connectivity during response inhibition in adolescents with attention-deficit/hyperactivity disorder and their unaffected siblings

PubMed Central

van Rooij, Daan; Hartman, Catharina A.; Mennes, Maarten; Oosterlaan, Jaap; Franke, Barbara; Rommelse, Nanda; Heslenfeld, Dirk; Faraone, Stephen V.; Buitelaar, Jan K.; Hoekstra, Pieter J.

2015-01-01

Introduction Response inhibition is one of the executive functions impaired in attention-deficit/hyperactivity disorder (ADHD). Increasing evidence indicates that altered functional and structural neural connectivity are part of the neurobiological basis of ADHD. Here, we investigated if adolescents with ADHD show altered functional connectivity during response inhibition compared to their unaffected siblings and healthy controls. Methods Response inhibition was assessed using the stop signal paradigm. Functional connectivity was assessed using psycho-physiological interaction analyses applied to BOLD time courses from seed regions within inferior- and superior frontal nodes of the response inhibition network. Resulting networks were compared between adolescents with ADHD (N = 185), their unaffected siblings (N = 111), and controls (N = 125). Results Control subjects showed stronger functional connectivity than the other two groups within the response inhibition network, while subjects with ADHD showed relatively stronger connectivity between default mode network (DMN) nodes. Stronger connectivity within the response inhibition network was correlated with lower ADHD severity, while stronger connectivity with the DMN was correlated with increased ADHD severity. Siblings showed connectivity patterns similar to controls during successful inhibition and to ADHD subjects during failed inhibition. Additionally, siblings showed decreased connectivity with the primary motor areas as compared to both participants with ADHD and controls. Discussion Subjects with ADHD fail to integrate activation within the response inhibition network and to inhibit connectivity with task-irrelevant regions. Unaffected siblings show similar alterations only during failed stop trials, as well as unique suppression of motor areas, suggesting compensatory strategies. These findings support the role of altered functional connectivity in understanding the neurobiology and familial transmission of ADHD. PMID:25610797
Altered neural connectivity during response inhibition in adolescents with attention-deficit/hyperactivity disorder and their unaffected siblings.

PubMed

van Rooij, Daan; Hartman, Catharina A; Mennes, Maarten; Oosterlaan, Jaap; Franke, Barbara; Rommelse, Nanda; Heslenfeld, Dirk; Faraone, Stephen V; Buitelaar, Jan K; Hoekstra, Pieter J

2015-01-01

Response inhibition is one of the executive functions impaired in attention-deficit/hyperactivity disorder (ADHD). Increasing evidence indicates that altered functional and structural neural connectivity are part of the neurobiological basis of ADHD. Here, we investigated if adolescents with ADHD show altered functional connectivity during response inhibition compared to their unaffected siblings and healthy controls. Response inhibition was assessed using the stop signal paradigm. Functional connectivity was assessed using psycho-physiological interaction analyses applied to BOLD time courses from seed regions within inferior- and superior frontal nodes of the response inhibition network. Resulting networks were compared between adolescents with ADHD (N = 185), their unaffected siblings (N = 111), and controls (N = 125). Control subjects showed stronger functional connectivity than the other two groups within the response inhibition network, while subjects with ADHD showed relatively stronger connectivity between default mode network (DMN) nodes. Stronger connectivity within the response inhibition network was correlated with lower ADHD severity, while stronger connectivity with the DMN was correlated with increased ADHD severity. Siblings showed connectivity patterns similar to controls during successful inhibition and to ADHD subjects during failed inhibition. Additionally, siblings showed decreased connectivity with the primary motor areas as compared to both participants with ADHD and controls. Subjects with ADHD fail to integrate activation within the response inhibition network and to inhibit connectivity with task-irrelevant regions. Unaffected siblings show similar alterations only during failed stop trials, as well as unique suppression of motor areas, suggesting compensatory strategies. These findings support the role of altered functional connectivity in understanding the neurobiology and familial transmission of ADHD.
Phase-Amplitude Response Functions for Transient-State Stimuli

PubMed Central

2013-01-01

Abstract The phase response curve (PRC) is a powerful tool to study the effect of a perturbation on the phase of an oscillator, assuming that all the dynamics can be explained by the phase variable. However, factors like the rate of convergence to the oscillator, strong forcing or high stimulation frequency may invalidate the above assumption and raise the question of how is the phase variation away from an attractor. The concept of isochrons turns out to be crucial to answer this question; from it, we have built up Phase Response Functions (PRF) and, in the present paper, we complete the extension of advancement functions to the transient states by defining the Amplitude Response Function (ARF) to control changes in the transversal variables. Based on the knowledge of both the PRF and the ARF, we study the case of a pulse-train stimulus, and compare the predictions given by the PRC-approach (a 1D map) to those given by the PRF-ARF-approach (a 2D map); we observe differences up to two orders of magnitude in favor of the 2D predictions, especially when the stimulation frequency is high or the strength of the stimulus is large. We also explore the role of hyperbolicity of the limit cycle as well as geometric aspects of the isochrons. Summing up, we aim at enlightening the contribution of transient effects in predicting the phase response and showing the limits of the phase reduction approach to prevent from falling into wrong predictions in synchronization problems. List of Abbreviations PRC phase response curve, phase resetting curve. PRF phase response function. ARF amplitude response function. PMID:23945295
Chief Business Officers' Functions: Responsibilities and Importance.

ERIC Educational Resources Information Center

Calver, Richard A.; Vogler, Daniel E.

1985-01-01

Reports on a survey of 177 chief business officers of public community colleges regarding their responsibilities and the importance they assigned to various role functions. Highlights findings concerning the perceived importance of fiscal/financial duties; endowments as a job function; role in shared planning; and personal attention given to…
OZONE-INDUCED RESPIRATORY SYMPTOMS AND LUNG FUNCTION DECREMENTS IN HUMANS: EXPOSURE-RESPONSE MODELS

EPA Science Inventory

Short duration exposure to ozone (<8 hr) is known to result in lung function decrements and respiratory symptoms in humans. The magnitudes of these responses are functions of ozone concentration (C), activity level measured by minute ventilation (Ve), duration of exposure (T), a...
Linking and Psychological Functioning in a Chinese Sample: The Multiple Mediation of Response to Positive Affect

ERIC Educational Resources Information Center

Yang, Hongfei; Li, Juan

2016-01-01

The present study examined the associations between linking, response to positive affect, and psychological functioning in Chinese college students. The results of conducting multiple mediation analyses indicated that emotion- and self-focused positive rumination mediated the relationship between linking and psychological functioning, whereas…
Dissociating interference-control processes between memory and response.

PubMed

Bissett, Patrick G; Nee, Derek Evan; Jonides, John

2009-09-01

The ability to mitigate interference is of central importance to cognition. Previous research has provided conflicting accounts about whether operations that resolve interference are singular in character or form a family of functions. Here, the authors examined the relationship between interference-resolution processes acting on working memory representations versus responses. The authors combined multiple forms of interference into a single paradigm by merging a directed-forgetting task, which induces proactive interference, with a stop-signal task, which taps response inhibition processes. The results demonstrated that proactive interference and response inhibition produced distinct behavioral signatures that did not interact. By contrast, combining two different measures of response inhibition by merging a go/no-go task variant and a stop signal produced overadditive behavioral interference, demonstrating that different forms of response inhibition tap the same processes. However, not all forms of response conflict interacted, suggesting that inhibition-related functions acting on response selection are dissociable from those acting on response inhibition. These results suggest that inhibition-related functions for memory and responses are dissociable. (c) 2009 APA, all rights reserved.

Science in Emergency Response at CDC: Structure and Functions.

PubMed

Iskander, John; Rose, Dale A; Ghiya, Neelam D

2017-09-01

Recent high-profile activations of the US Centers for Disease Control and Prevention (CDC) Emergency Operations Center (EOC) include responses to the West African Ebola and Zika virus epidemics. Within the EOC, emergency responses are organized according to the Incident Management System, which provides a standardized structure and chain of command, regardless of whether the EOC activation occurs in response to an outbreak, natural disaster, or other type of public health emergency. By embedding key scientific roles, such as the associate director for science, and functions within a Scientific Response Section, the current CDC emergency response structure ensures that both urgent and important science issues receive needed attention. Key functions during emergency responses include internal coordination of scientific work, data management, information dissemination, and scientific publication. We describe a case example involving the ongoing Zika virus response that demonstrates how the scientific response structure can be used to rapidly produce high-quality science needed to answer urgent public health questions and guide policy. Within the context of emergency response, longer-term priorities at CDC include both streamlining administrative requirements and funding mechanisms for scientific research.
Functional MR imaging assessment of a non-responsive brain injured patient.

PubMed

Moritz, C H; Rowley, H A; Haughton, V M; Swartz, K R; Jones, J; Badie, B

2001-10-01

Functional magnetic resonance imaging (fMRI) was requested to assist in the evaluation of a comatose 38-year-old woman who had sustained multiple cerebral contusions from a motor vehicle accident. Previous electrophysiologic studies suggested absence of thalamocortical processing in response to median nerve stimulation. Whole-brain fMRI was performed utilizing visual, somatosensory, and auditory stimulation paradigms. Results demonstrated intact task-correlated sensory and cognitive blood oxygen level dependent (BOLD) hemodynamic response to stimuli. Electrodiagnostic studies were repeated and evoked potentials indicated supratentorial recovery in the cerebrum. At 3-months post trauma the patient had recovered many cognitive & sensorimotor functions, accurately reflecting the prognostic fMRI evaluation. These results indicate that fMRI examinations may provide a useful evaluation for brain function in non-responsive brain trauma patients.
Spectral characterization of plastic scintillation detector response as a function of magnetic field strength

NASA Astrophysics Data System (ADS)

Simiele, E.; Kapsch, R.-P.; Ankerhold, U.; Culberson, W.; DeWerd, L.

2018-04-01

The purpose of this work was to characterize intensity and spectral response changes in a plastic scintillation detector (PSD) as a function of magnetic field strength. Spectra measurements as a function of magnetic field strength were performed using an optical spectrometer. The response of both a PSD and PMMA fiber were investigated to isolate the changes in response from the scintillator and the noise signal as a function of magnetic field strength. All irradiations were performed in water at a photon beam energy of 6 MV. Magnetic field strengths of (0, ±0.35, ±0.70, ±1.05, and ±1.40) T were investigated. Four noise subtraction techniques were investigated to evaluate the impact on the resulting noise-subtracted scintillator response with magnetic field strength. The noise subtraction methods included direct spectral subtraction, the spectral method, and variants thereof. The PMMA fiber exhibited changes in response of up to 50% with magnetic field strength due to the directional light emission from \\breve{C} erenkov radiation. The PSD showed increases in response of up to 10% when not corrected for the noise signal, which agrees with previous investigations of scintillator response in magnetic fields. Decreases in the \\breve{C} erenkov light ratio with negative field strength were observed with a maximum change at ‑1.40 T of 3.2% compared to 0 T. The change in the noise-subtracted PSD response as a function of magnetic field strength varied with the noise subtraction technique used. Even after noise subtraction, the PSD exhibited changes in response of up to 5.5% over the four noise subtraction methods investigated.
Variability of non-response to aspirin in patients with peripheral arterial occlusive disease during long-term follow-up.

PubMed

Linnemann, Birgit; Prochnow, Stephanie; Mani, Helen; Schwonberg, Jan; Lindhoff-Last, Edelgard

2009-10-01

Non-responsiveness to aspirin as detected by laboratory tests may identify patients at high risk for future vascular events. The aim of this prospective study was to evaluate whether non-responsiveness to aspirin is stable over time. Ninety-eight patients with stable peripheral arterial occlusive disease (PAOD) treated with 100 mg/d aspirin were followed over a median timeframe of 17 months. Platelet function tests were performed initially and at follow-up using arachidonic acid-induced light transmittance aggregometry (LTA) in native platelet-rich plasma with the Behring Coagulation Timer and by measuring the collagen-epinephrine closure time (CT) on a Platelet Function Analyzer (PFA-100). When determining platelet function using LTA, four patients (4.1%) had residual platelet function (i.e., MaxAggr > or =78%) despite aspirin treatment, whereas, according to the PFA-100 results, 12 patients (12.2%) were identified as non-responders (i.e., CT <192 s). Fifty-seven patients who were still under treatment with 100 mg/d aspirin at the time of follow-up provided a second blood sample. Further platelet function tests with the PFA-100 system identified a persistent non-responsiveness to aspirin over time in three patients (5.3%) whereas four (7.0%) and 15 (26.3%) patients had changes in response status when platelet function was assessed by LTA and on the PFA-100(R), respectively. We conclude that true non-responsiveness to aspirin is a rare phenomenon in stable PAOD patients. Furthermore, we conclude that in a number of patients, aspirin non-responsiveness is not stable over time.
Alongshore wind forcing of coastal sea level as a function of frequency

USGS Publications Warehouse

Ryan, H.F.; Noble, M.A.

2006-01-01

The amplitude of the frequency response function between coastal alongshore wind stress and adjusted sea level anomalies along the west coast of the United States increases linearly as a function of the logarithm (log10) of the period for time scales up to at least 60, and possibly 100, days. The amplitude of the frequency response function increases even more rapidly at longer periods out to at least 5 yr. At the shortest periods, the amplitude of the frequency response function is small because sea level is forced only by the local component of the wind field. The regional wind field, which controls the wind-forced response in sea level for periods between 20 and 100 days, not only has much broader spatial scales than the local wind, but also propagates along the coast in the same direction as continental shelf waves. Hence, it has a stronger coupling to and an increased frequency response for sea level. At periods of a year or more, observed coastal sea level fluctuations are not only forced by the regional winds, but also by joint correlations among the larger-scale climatic patterns associated with El Nin??o. Therefore, the amplitude of the frequency response function is large, despite the fact that the energy in the coastal wind field is relatively small. These data show that the coastal sea level response to wind stress forcing along the west coast of the United States changes in a consistent and predictable pattern over a very broad range of frequencies with time scales from a few days to several years.
Different responses of functional traits and diversity of stream macroinvertebrates to environmental and spatial factors in the Xishuangbanna watershed of the upper Mekong River Basin, China.

PubMed

Ding, Ning; Yang, Weifang; Zhou, Yunlei; González-Bergonzoni, Ivan; Zhang, Jie; Chen, Kai; Vidal, Nicolas; Jeppesen, Erik; Liu, Zhengwen; Wang, Beixin

2017-01-01

Functional traits and diversity indices have provided new insights into community responses to stressors. Most traits of aquatic organisms have frequently been tested for predictability and geographical stability in response to environmental variables, but such tests of functional diversity indices are rare. We sampled macroinvertebrates at 18 reference sites (RS) and 35 disturbed sites (DS) from headwater streams in the upper Mekong River Basin, Xishuangbanna (XSBN), China. We selected 29 qualitative categories of eight traits and then calculated five functional diversity indices, namely functional richness (FRic), functional evenness (FEve), functional dispersion (FDis), functional divergence (FDiv) and Rao's Quadratic Entropy (RaoQ), and two trait diversity indices, namely trait richness (TR) and trait diversity (TD). We used combination of RLQ and fourth-corner to examine the response of traits and functional diversity to the disturbance and environmental variables. We used variance partitioning to explore the relative role of environmental variables and spatial factors in constraining trait composition and functional diversity. We found that the relative frequency of ten trait categories, and the values of TD, TR, FRic and FDis in RS were significantly different (p<0.05) from DS. In addition, the seven traits (except for "habit") demonstrated a predictable response of trait patterns along the integrative environmental gradients. Environmental variables significantly contributed to most of the traits, functional diversity and trait diversity. However, spatial variables were mainly significant in shaping ecological traits, FRic and FEve. Our results confirm the dominant role of environmental variables in the determination of community trait composition and functional diversity, and substantiate the contribution of spatial vectors in explaining the variance of functional traits and diversity. We conclude that the traits "Refuge", "External protection", "Respiration" and "Body shape", and diversity indices FDis, TD, and TR are promising indicators of stream conditions at XSBN. Copyright © 2016 Elsevier B.V. All rights reserved.
PreSMA stimulation changes task-free functional connectivity in the fronto-basal-ganglia that correlates with response inhibition efficiency.

PubMed

Xu, Benjamin; Sandrini, Marco; Wang, Wen-Tung; Smith, Jason F; Sarlls, Joelle E; Awosika, Oluwole; Butman, John A; Horwitz, Barry; Cohen, Leonardo G

2016-09-01

Previous work using transcranial magnetic stimulation (TMS) demonstrated that the right presupplementary motor area (preSMA), a node in the fronto-basal-ganglia network, is critical for response inhibition. However, TMS influences interconnected regions, raising the possibility of a link between the preSMA activity and the functional connectivity within the network. To understand this relationship, we applied single-pulse TMS to the right preSMA during functional magnetic resonance imaging when the subjects were at rest to examine changes in neural activity and functional connectivity within the network in relation to the efficiency of response inhibition evaluated with a stop-signal task. The results showed that preSMA-TMS increased activation in the right inferior-frontal cortex (rIFC) and basal ganglia and modulated their task-free functional connectivity. Both the TMS-induced changes in the basal-ganglia activation and the functional connectivity between rIFC and left striatum, and of the overall network correlated with the efficiency of response inhibition and with the white-matter microstructure along the preSMA-rIFC pathway. These results suggest that the task-free functional and structural connectivity between the rIFCop and basal ganglia are critical to the efficiency of response inhibition. Hum Brain Mapp 37:3236-3249, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Catecholamine responses to virtual combat: implications for post-traumatic stress and dimensions of functioning.

PubMed

Highland, Krista B; Costanzo, Michelle E; Jovanovic, Tanja; Norrholm, Seth D; Ndiongue, Rochelle B; Reinhardt, Brian J; Rothbaum, Barbara; Rizzo, Albert A; Roy, Michael J

2015-01-01

Posttraumatic stress disorder (PTSD) symptoms can result in functional impairment among service members (SMs), even in those without a clinical diagnosis. The variability in outcomes may be related to underlying catecholamine mechanisms. Individuals with PTSD tend to have elevated basal catecholamine levels, though less is known regarding catecholamine responses to trauma-related stimuli. We assessed whether catecholamine responses to a virtual combat environment impact the relationship between PTSD symptom clusters and elements of functioning. Eighty-seven clinically healthy SMs, within 2 months after deployment to Iraq or Afghanistan, completed self-report measures, viewed virtual-reality (VR) combat sequences, and had sequential blood draws. Norepinephrine responses to VR combat exposure moderated the relationship between avoidance symptoms and scales of functioning including physical functioning, physical-role functioning, and vitality. Among those with high levels of avoidance, norepinephrine change was inversely associated with functional status, whereas a positive correlation was observed for those with low levels of avoidance. Our findings represent a novel use of a virtual environment to display combat-related stimuli to returning SMs to elucidate mind-body connections inherent in their responses. The insight gained improves our understanding of post-deployment symptoms and quality of life in SMs and may facilitate enhancements in treatment. Further research is needed to validate these findings in other populations and to define the implications for treatment effectiveness.
Correlation between electrical and hemodynamic responses during visual stimulation with graded contrasts

NASA Astrophysics Data System (ADS)

Si, Juanning; Zhang, Xin; Li, Yuejun; Zhang, Yujin; Zuo, Nianming; Jiang, Tianzi

2016-09-01

Brain functional activity involves complex cellular, metabolic, and vascular chain reactions, making it difficult to comprehend. Electroencephalography (EEG) and functional near infrared spectroscopy (fNIRS) have been combined into a multimodal neuroimaging method that captures both electrophysiological and hemodynamic information to explore the spatiotemporal characteristics of brain activity. Because of the significance of visually evoked functional activity in clinical applications, numerous studies have explored the amplitude of the visual evoked potential (VEP) to clarify its relationship with the hemodynamic response. However, relatively few studies have investigated the influence of latency, which has been frequently used to diagnose visual diseases, on the hemodynamic response. Moreover, because the latency and the amplitude of VEPs have different roles in coding visual information, investigating the relationship between latency and the hemodynamic response should be helpful. In this study, checkerboard reversal tasks with graded contrasts were used to evoke visual functional activity. Both EEG and fNIRS were employed to investigate the relationship between neuronal electrophysiological activities and the hemodynamic responses. The VEP amplitudes were linearly correlated with the hemodynamic response, but the VEP latency showed a negative linear correlation with the hemodynamic response.
Screening vaccine formulations for biological activity using fresh human whole blood

PubMed Central

Brookes, Roger H; Hakimi, Jalil; Ha, Yukyung; Aboutorabian, Sepideh; Ausar, Salvador F; Hasija, Manvi; Smith, Steven G; Todryk, Stephen M; Dockrell, Hazel M; Rahman, Nausheen

2014-01-01

Understanding the relevant biological activity of any pharmaceutical formulation destined for human use is crucial. For vaccine-based formulations, activity must reflect the expected immune response, while for non-vaccine therapeutic agents, such as monoclonal antibodies, a lack of immune response to the formulation is desired. During early formulation development, various biochemical and biophysical characteristics can be monitored in a high-throughput screening (HTS) format. However, it remains impractical and arguably unethical to screen samples in this way for immunological functionality in animal models. Furthermore, data for immunological functionality lag formulation design by months, making it cumbersome to relate back to formulations in real-time. It is also likely that animal testing may not accurately reflect the response in humans. For a more effective formulation screen, a human whole blood (hWB) approach can be used to assess immunological functionality. The functional activity relates directly to the human immune response to a complete formulation (adjuvant/antigen) and includes adjuvant response, antigen response, adjuvant-modulated antigen response, stability, and potentially safety. The following commentary discusses the hWB approach as a valuable new tool to de-risk manufacture, formulation design, and clinical progression. PMID:24401565
Screening vaccine formulations for biological activity using fresh human whole blood.

PubMed

Brookes, Roger H; Hakimi, Jalil; Ha, Yukyung; Aboutorabian, Sepideh; Ausar, Salvador F; Hasija, Manvi; Smith, Steven G; Todryk, Stephen M; Dockrell, Hazel M; Rahman, Nausheen

2014-01-01

Understanding the relevant biological activity of any pharmaceutical formulation destined for human use is crucial. For vaccine-based formulations, activity must reflect the expected immune response, while for non-vaccine therapeutic agents, such as monoclonal antibodies, a lack of immune response to the formulation is desired. During early formulation development, various biochemical and biophysical characteristics can be monitored in a high-throughput screening (HTS) format. However, it remains impractical and arguably unethical to screen samples in this way for immunological functionality in animal models. Furthermore, data for immunological functionality lag formulation design by months, making it cumbersome to relate back to formulations in real-time. It is also likely that animal testing may not accurately reflect the response in humans. For a more effective formulation screen, a human whole blood (hWB) approach can be used to assess immunological functionality. The functional activity relates directly to the human immune response to a complete formulation (adjuvant/antigen) and includes adjuvant response, antigen response, adjuvant-modulated antigen response, stability, and potentially safety. The following commentary discusses the hWB approach as a valuable new tool to de-risk manufacture, formulation design, and clinical progression.
Testing functional trait-based mechanisms underpinning plant responses to grazing and linkages to ecosystem functioning in grasslands

NASA Astrophysics Data System (ADS)

Zheng, S. X.; Li, W. H.; Lan, Z. C.; Ren, H. Y.; Wang, K. B.; Bai, Y. F.

2014-09-01

Abundant evidence has shown that grazing alters plant functional traits, ecological strategies, community structure, and ecosystem functioning of grasslands. Few studies, however, have examined how plant responses to grazing are mediated by resource availability and functional group identity. We test functional trait-based mechanisms underlying the responses of different life forms to grazing and linkages to ecosystem functioning along a soil moisture gradient in the Inner Mongolia grassland. A principal component analysis (PCA) based on 9 traits × 276 species matrix showed that the plant size spectrum (i.e., individual biomass), leaf economics spectrum (leaf N content and leaf density), and light competition spectrum (height and stem-leaf biomass ratio) distinguished plant species responses to grazing. The three life forms exhibited differential strategies as indicated by trait responses to grazing. The annuals and biennials adopted grazing-tolerant strategies associated with high growth rate, reflected by high leaf N content and specific leaf area. The perennial grasses exhibited grazing-tolerant strategies associated with great regrowth capacity and high palatability scores, whereas perennial forbs showed grazing-avoidant strategies with short stature and low palatability scores. In addition, the dominant perennial bunchgrasses exhibited mixed tolerance-resistance strategies to grazing and mixed acquisitive-conservative strategies in resource utilization. Grazing increased the relative abundance of perennial forbs with low palatability in the wet and fertile meadow, but it promoted perennial grasses with high palatability in the dry and infertile typical steppe. Our findings suggest that the effects of grazing on plant functional traits are dependent on both the abiotic (e.g., soil moisture) and biotic (e.g., plant functional group identity and composition) factors. Grazing-induced shifts in functional group composition are largely dependent on resource availability, particularly water availability.
Effects of response preference on resistance to change.

PubMed

Ringdahl, Joel E; Berg, Wendy K; Wacker, David P; Crook, Kayla; Molony, Maggie A; Vargo, Kristina K; Neurnberger, Jodi E; Zabala, Karla; Taylor, Christopher J

2018-01-01

Treatments based on differential reinforcement of alternative behavior, such as functional communication training, are widely used. Research regarding the maintenance of related treatment effects is limited. Nevin and Wacker (2013) provided a conceptual framework, rooted in behavioral momentum theory, for the study of treatment maintenance that addressed two components: (a) reemergence of problem behavior, and (b) continued expression of appropriate behavior. In the few studies on this topic, focus has been on variables impacting the reemergence of problem behavior, with fewer studies evaluating the persistence of appropriate behavior. Given the findings from applied research related to functional communication training, variables related to response topography, such as response preference, may impact this aspect of maintenance. In the current study, the impact of response preference on persistence was evaluated in the context of functional communication training for individuals who did not exhibit problem behavior (Experiment 1) and for individuals with a history of reinforcement for problem behavior (Experiment 2). High-preferred mands were more persistent than low-preferred mands. These findings suggest that response related variables, such as response preference, impact response persistence and further suggest that response related variables should be considered when developing interventions such as functional communication training. © 2018 Society for the Experimental Analysis of Behavior.
Woman and partner-perceived partner responses predict pain and sexual satisfaction in provoked vestibulodynia (PVD) couples.

PubMed

Rosen, Natalie O; Bergeron, Sophie; Leclerc, Bianca; Lambert, Bernard; Steben, Marc

2010-11-01

Provoked vestibulodynia (PVD) is a highly prevalent vulvovaginal pain condition that results in significant sexual dysfunction, psychological distress, and reduced quality of life. Although some intra-individual psychological factors have been associated with PVD, studies to date have neglected the interpersonal context of this condition. We examined whether partner responses to women's pain experience-from the perspective of both the woman and her partner-are associated with pain intensity, sexual function, and sexual satisfaction. One hundred ninety-one couples (M age for women=33.28, standard deviation [SD]=12.07, M age for men=35.79, SD=12.44) in which the woman suffered from PVD completed the spouse response scale of the Multidimensional Pain Inventory, assessing perceptions of partners' responses to the pain. Women with PVD also completed measures of pain, sexual function, sexual satisfaction, depression, and dyadic adjustment. Dependent measures were women's responses to: (i) a horizontal analog scale assessing the intensity of their pain during intercourse; (ii) the Female Sexual Function Index; and (iii) the Global Measure of Sexual Satisfaction Scale. Controlling for depression, higher solicitous partner responses were associated with higher levels of women's vulvovaginal pain intensity. This association was significant for partner-perceived responses (β=0.29, P<0.001) and for woman-perceived partner responses (β=0.16, P=0.04). After controlling for sexual function and dyadic adjustment, woman-perceived greater solicitous partner responses (β=0.16, P=0.02) predicted greater sexual satisfaction. Partner-perceived responses did not predict women's sexual satisfaction. Partner responses were not associated with women's sexual function. Findings support the integration of dyadic processes in the conceptualization and treatment of PVD by suggesting that partner responses to pain affect pain intensity and sexual satisfaction in affected women. © 2010 International Society for Sexual Medicine.
33 CFR 155.1040 - Response plan requirements for unmanned tank barges carrying oil as a primary cargo.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the towing vessel crew and facility or fleeting area personnel, if any, to initiate a response and... functional areas and must further include information for key components within each functional area: (i...) Spill response operations; (vi) Planning; (vii) Logistics support; and (viii) Finance. (5) The...
33 CFR 155.1040 - Response plan requirements for unmanned tank barges carrying oil as a primary cargo.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the towing vessel crew and facility or fleeting area personnel, if any, to initiate a response and... functional areas and must further include information for key components within each functional area: (i...) Spill response operations; (vi) Planning; (vii) Logistics support; and (viii) Finance. (5) The...
33 CFR 155.1035 - Response plan requirements for manned vessels carrying oil as a primary cargo.

Code of Federal Regulations, 2014 CFR

2014-07-01

... be used to manage the response actions. This structure must include the following functional areas and must further include information for key components within each functional area: (i) Command and... operations; (vi) Planning; (vii) Logistics support; and (viii) Finance. (5) The responsibilities of, duties...
33 CFR 155.1040 - Response plan requirements for unmanned tank barges carrying oil as a primary cargo.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the towing vessel crew and facility or fleeting area personnel, if any, to initiate a response and... functional areas and must further include information for key components within each functional area: (i...) Spill response operations; (vi) Planning; (vii) Logistics support; and (viii) Finance. (5) The...
33 CFR 155.1035 - Response plan requirements for manned vessels carrying oil as a primary cargo.

Code of Federal Regulations, 2013 CFR

2013-07-01

... be used to manage the response actions. This structure must include the following functional areas and must further include information for key components within each functional area: (i) Command and... operations; (vi) Planning; (vii) Logistics support; and (viii) Finance. (5) The responsibilities of, duties...
33 CFR 155.1040 - Response plan requirements for unmanned tank barges carrying oil as a primary cargo.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the towing vessel crew and facility or fleeting area personnel, if any, to initiate a response and... functional areas and must further include information for key components within each functional area: (i...) Spill response operations; (vi) Planning; (vii) Logistics support; and (viii) Finance. (5) The...

33 CFR 155.1035 - Response plan requirements for manned vessels carrying oil as a primary cargo.

Code of Federal Regulations, 2011 CFR

2011-07-01

... be used to manage the response actions. This structure must include the following functional areas and must further include information for key components within each functional area: (i) Command and... operations; (vi) Planning; (vii) Logistics support; and (viii) Finance. (5) The responsibilities of, duties...
33 CFR 155.1035 - Response plan requirements for manned vessels carrying oil as a primary cargo.

Code of Federal Regulations, 2012 CFR

2012-07-01

... be used to manage the response actions. This structure must include the following functional areas and must further include information for key components within each functional area: (i) Command and... operations; (vi) Planning; (vii) Logistics support; and (viii) Finance. (5) The responsibilities of, duties...
Short-Term Variations in Response Distribution to Cortical Stimulation

ERIC Educational Resources Information Center

Lesser, Ronald P.; Lee, Hyang Woon; Webber, W. R. S.; Prince, Barry; Crone, Nathan E.; Miglioretti, Diana L.

2008-01-01

Patterns of responses in the cerebral cortex can vary, and are influenced by pre-existing cortical function, but it is not known how rapidly these variations can occur in humans. We investigated how rapidly response patterns to electrical stimulation can vary in intact human brain. We also investigated whether the type of functional change…
A functional dissociation of conflict processing within anterior cingulate cortex.

PubMed

Kim, Chobok; Kroger, James K; Kim, Jeounghoon

2011-02-01

Goal-directed behavior requires cognitive control to regulate the occurrence of conflict. The dorsal anterior cingulate cortex (dACC) has been suggested in detecting response conflict during various conflict tasks. Recent findings, however, have indicated not only that two distinct subregions of dACC are involved in conflict processing but also that the conflict occurs at both perceptual and response levels. In this study, we sought to examine whether perceptual and response conflicts are functionally dissociated in dACC. Thirteen healthy subjects performed a version of the Stroop task during functional magnetic resonance imaging (fMRI) scanning. We identified a functional dissociation of the caudal dACC (cdACC) and the rostral dACC (rdACC) in their responses to different sources of conflict. The cdACC was selectively engaged in perceptual conflict whereas the rdACC was more active in response conflict. Further, the dorsolateral prefrontal cortex (DLPFC) was coactivated not with cdACC but with rdACC. We suggest that cdACC plays an important role in regulative processing of perceptual conflict whereas rdACC is involved in detecting response conflict. Copyright © 2010 Wiley-Liss, Inc.
Defining and quantifying the resilience of responses to disturbance: a conceptual and modelling approach from soil science

PubMed Central

Todman, L. C.; Fraser, F. C.; Corstanje, R.; Deeks, L. K.; Harris, J. A.; Pawlett, M.; Ritz, K.; Whitmore, A. P.

2016-01-01

There are several conceptual definitions of resilience pertaining to environmental systems and, even if resilience is clearly defined in a particular context, it is challenging to quantify. We identify four characteristics of the response of a system function to disturbance that relate to “resilience”: (1) degree of return of the function to a reference level; (2) time taken to reach a new quasi-stable state; (3) rate (i.e. gradient) at which the function reaches the new state; (4) cumulative magnitude of the function (i.e. area under the curve) before a new state is reached. We develop metrics to quantify these characteristics based on an analogy with a mechanical spring and damper system. Using the example of the response of a soil function (respiration) to disturbance, we demonstrate that these metrics effectively discriminate key features of the dynamic response. Although any one of these characteristics could define resilience, each may lead to different insights and conclusions. The salient properties of a resilient response must thus be identified for different contexts. Because the temporal resolution of data affects the accurate determination of these metrics, we recommend that at least twelve measurements are made over the temporal range for which the response is expected. PMID:27329053
Changes in composition and abundance of functional groups of arctic fungi in response to long-term summer warming

PubMed Central

Semenova, Tatiana A.; Morgado, Luis N.; Welker, Jeffrey M.

2016-01-01

We characterized fungal communities in dry and moist tundra and investigated the effect of long-term experimental summer warming on three aspects of functional groups of arctic fungi: richness, community composition and species abundance. Warming had profound effects on community composition, abundance, and, to a lesser extent, on richness of fungal functional groups. In addition, our data show that even within functional groups, the direction and extent of response to warming tend to be species-specific and we recommend that studies on fungal communities and their roles in nutrient cycling take into account species-level responses. PMID:27881760
On the dependence of response inhibition processes on sensory modality.

PubMed

Bodmer, Benjamin; Beste, Christian

2017-04-01

The ability to inhibit responses is a central sensorimotor function but only recently the importance of sensory processes for motor inhibition mechanisms went more into the research focus. In this regard it is elusive, whether there are differences between sensory modalities to trigger response inhibition processes. Due to functional neuroanatomical considerations strong differences may exist, for example, between the visual and the tactile modality. In the current study we examine what neurophysiological mechanisms as well as functional neuroanatomical networks are modulated during response inhibition. Therefore, a Go/NoGo-paradigm employing a novel combination of visual, tactile, and visuotactile stimuli was used. The data show that the tactile modality is more powerful than the visual modality to trigger response inhibition processes. However, the tactile modality loses its efficacy to trigger response inhibition processes when being combined with the visual modality. This may be due to competitive mechanisms leading to a suppression of certain sensory stimuli and the response selection level. Variations in sensory modalities specifically affected conflict monitoring processes during response inhibition by modulating activity in a frontal parietal network including the right inferior frontal gyrus, anterior cingulate cortex and the temporoparietal junction. Attentional selection processes are not modulated. The results suggest that the functional neuroanatomical networks involved in response inhibition critically depends on the nature of the sensory input. Hum Brain Mapp 38:1941-1951, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Functional connectivity correlates of response inhibition impairment in anorexia nervosa.

PubMed

Collantoni, Enrico; Michelon, Silvia; Tenconi, Elena; Degortes, Daniela; Titton, Francesca; Manara, Renzo; Clementi, Maurizio; Pinato, Claudia; Forzan, Monica; Cassina, Matteo; Santonastaso, Paolo; Favaro, Angela

2016-01-30

Anorexia nervosa (AN) is a disorder characterized by high levels of cognitive control and behavioral perseveration. The present study aims at exploring inhibitory control abilities and their functional connectivity correlates in patients with AN. Inhibitory control - an executive function that allows the realization of adaptive behavior according to environmental contingencies - has been assessed by means of the Stop-Signal paradigm. The study involved 155 patients with lifetime AN and 102 healthy women. A subsample underwent resting-state functional magnetic resonance imaging and was genotyped for COMT and 5-HTTLPR polymorphisms. AN patients showed an impaired response inhibition and a disruption of the functional connectivity of the ventral attention circuit, a neural network implicated in behavioral response when a stimulus occurs unexpected. The 5-HTTLPR genotype appears to significantly interact with the functional connectivity of ventral attention network in explaining task performance in both patients and controls, suggesting a role of the serotoninergic system in mechanisms of response selection. The disruption of the ventral attention network in patients with AN suggests lower efficiency of bottom-up signal filtering, which might be involved in difficulties to adapt behavioral responses to environmental needs. Our findings deserve further research to confirm their scientific and therapeutic implications. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
The Role of Inhibition in Age-related Off-Topic Verbosity: Not Access but Deletion and Restraint Functions.

PubMed

Yin, Shufei; Peng, Huamao

2016-01-01

The speech of older adults is commonly described as verbose and off-topic, which is thought to influence their social communication. This study investigated the role of inhibition in age-related off-topic verbosity (OTV). Inhibition consists of three functions: access, deletion, and restraint. The access function is responsible for preventing irrelevant information from accessing the attention center (pre-mechanism of inhibition); The deletion function is responsible for deleting previously relevant but currently irrelevant information from working memory, and the restraint function is responsible for restraining strong but inappropriate responses (post-mechanisms of inhibition). A referential communication task was used to determine whether OTV was influenced by the pre-mechanism of inhibition. A self-involved event interview task was used to investigate the effect of the post-mechanisms of inhibition on OTV. Results showed that the OTV of the elderly participants was associated with an age-related decline in the post-mechanisms of inhibition, while the OTV exhibited by young adults was most likely due to deficits in the pre-mechanism function of inhibition. This research contributed to fill gaps in the existing knowledge about the potential relationship between specific functions of inhibition and age-related OTV.
Analyzing the multiple functions of stereotypical behavior for students with autism: implications for assessment and treatment.

PubMed

Kennedy, C H; Meyer, K A; Knowles, T; Shukla, S

2000-01-01

We studied behavioral functions associated with stereotypical responses for students with autism. In Study 1, analogue functional analyses (attention, demand, no-attention, and recreation conditions) were conducted for 5 students. Results suggested that stereotypy was multiply determined or occurred across all assessment conditions. For 2 students, stereotypy was associated with positive and negative reinforcement and the absence of environmental stimulation. For 2 other students, stereotypy occurred at high levels across all experimental conditions. For the 5th student, stereotypy was associated with negative reinforcement and the absence of environmental stimulation. In Study 2, the stereotypy of 1 student was further analyzed on a function-by-function basis. Within a concurrent-schedules procedure, alternative responses were taught to the student using functional communication training. The results of Study 2 showed that similar topographies of stereotypy, based on qualitatively different reinforcers, were reduced only when differential reinforcement contingencies for alternative forms of communication were implemented for specific response-reinforcer relations. Our results suggest that the causes of stereotypy for students with autism are complex and that the presumed association between response topography and behavioral function may be less important than previously realized.
Analyzing the multiple functions of stereotypical behavior for students with autism: implications for assessment and treatment.

PubMed Central

Kennedy, C H; Meyer, K A; Knowles, T; Shukla, S

2000-01-01

We studied behavioral functions associated with stereotypical responses for students with autism. In Study 1, analogue functional analyses (attention, demand, no-attention, and recreation conditions) were conducted for 5 students. Results suggested that stereotypy was multiply determined or occurred across all assessment conditions. For 2 students, stereotypy was associated with positive and negative reinforcement and the absence of environmental stimulation. For 2 other students, stereotypy occurred at high levels across all experimental conditions. For the 5th student, stereotypy was associated with negative reinforcement and the absence of environmental stimulation. In Study 2, the stereotypy of 1 student was further analyzed on a function-by-function basis. Within a concurrent-schedules procedure, alternative responses were taught to the student using functional communication training. The results of Study 2 showed that similar topographies of stereotypy, based on qualitatively different reinforcers, were reduced only when differential reinforcement contingencies for alternative forms of communication were implemented for specific response-reinforcer relations. Our results suggest that the causes of stereotypy for students with autism are complex and that the presumed association between response topography and behavioral function may be less important than previously realized. PMID:11214031
Experiment K-7-19: Pineal Physiology After Spaceflight: Relation to Rat Gonadal Function

NASA Technical Reports Server (NTRS)

Holley, D. C.; Soliman, M. R. I.; Krasnov, I.; Asadi, H.

1994-01-01

The function of pineal exposed to microgravity and spaceflight is studied. It is found that the spaceflight resulted in a stress response as indicated by adrenal hypertrophy, that gonadal function was compromised, and that the pineal may be linked as part of the mechanisms of the response noted.
The New Venture Growth: Functional Differentiation and the Need for Human Resource Development Interventions.

ERIC Educational Resources Information Center

Ardichvili, Alexander; Harmon, Brian; Cardozo, Richard N.; Reynolds, Paul D.; Williams, Mary L.

1998-01-01

New businesses (n=539) were surveyed in 1986-87 and 1992-93. People responsible for start-up retained responsibility for marketing and related functions. Production, service delivery, purchasing, shipping, and computer functions were most often delegated, usually to internal employees. Organization size did not influence functional…
Neutron spectroscopy with scintillation detectors using wavelets

NASA Astrophysics Data System (ADS)

Hartman, Jessica

The purpose of this research was to study neutron spectroscopy using the EJ-299-33A plastic scintillator. This scintillator material provided a novel means of detection for fast neutrons, without the disadvantages of traditional liquid scintillation materials. EJ-299-33A provided a more durable option to these materials, making it less likely to be damaged during handling. Unlike liquid scintillators, this plastic scintillator was manufactured from a non-toxic material, making it safer to use, as well as easier to design detectors. The material was also manufactured with inherent pulse shape discrimination abilities, making it suitable for use in neutron detection. The neutron spectral unfolding technique was developed in two stages. Initial detector response function modeling was carried out through the use of the MCNPX Monte Carlo code. The response functions were developed for a monoenergetic neutron flux. Wavelets were then applied to smooth the response function. The spectral unfolding technique was applied through polynomial fitting and optimization techniques in MATLAB. Verification of the unfolding technique was carried out through the use of experimentally determined response functions. These were measured on the neutron source based on the Van de Graff accelerator at the University of Kentucky. This machine provided a range of monoenergetic neutron beams between 0.1 MeV and 24 MeV, making it possible to measure the set of response functions of the EJ-299-33A plastic scintillator detector to neutrons of specific energies. The response of a plutonium-beryllium (PuBe) source was measured using the source available at the University of Nevada, Las Vegas. The neutron spectrum reconstruction was carried out using the experimentally measured response functions. Experimental data was collected in the list mode of the waveform digitizer. Post processing of this data focused on the pulse shape discrimination analysis of the recorded response functions to remove the effects of photons and allow for source characterization based solely on the neutron response. The unfolding technique was performed through polynomial fitting and optimization techniques in MATLAB, and provided an energy spectrum for the PuBe source.
Transient Receptor Potential Vanilloid 2 Regulates Myocardial Response to Exercise

PubMed Central

Naticchioni, Mindi; Karani, Rajiv; Smith, Margaret A.; Onusko, Evan; Robbins, Nathan; Jiang, Min; Radzyukevich, Tatiana; Fulford, Logan; Gao, Xu; Apel, Ryan; Heiny, Judith; Rubinstein, Jack; Koch, Sheryl E.

2015-01-01

The myocardial response to exercise is an adaptive mechanism that permits the heart to maintain cardiac output via improved cardiac function and development of hypertrophy. There are many overlapping mechanisms via which this occurs with calcium handling being a crucial component of this process. Our laboratory has previously found that the stretch sensitive TRPV2 channels are active regulators of calcium handling and cardiac function under baseline conditions based on our observations that TRPV2-KO mice have impaired cardiac function at baseline. The focus of this study was to determine the cardiac function of TRPV2-KO mice under exercise conditions. We measured skeletal muscle at baseline in WT and TRPV2-KO mice and subjected them to various exercise protocols and measured the cardiac response using echocardiography and molecular markers. Our results demonstrate that the TRPV2-KO mouse did not tolerate forced exercise although they became increasingly exercise tolerant with voluntary exercise. This occurs as the cardiac function deteriorates further with exercise. Thus, our conclusion is that TRPV2-KO mice have impaired cardiac functional response to exercise. PMID:26356305
Modeling non-linear growth responses to temperature and hydrology in wetland trees

NASA Astrophysics Data System (ADS)

Keim, R.; Allen, S. T.

2016-12-01

Growth responses of wetland trees to flooding and climate variations are difficult to model because they depend on multiple, apparently interacting factors, but are a critical link in hydrological control of wetland carbon budgets. To more generally understand tree growth to hydrological forcing, we modeled non-linear responses of tree ring growth to flooding and climate at sub-annual time steps, using Vaganov-Shashkin response functions. We calibrated the model to six baldcypress tree-ring chronologies from two hydrologically distinct sites in southern Louisiana, and tested several hypotheses of plasticity in wetlands tree responses to interacting environmental variables. The model outperformed traditional multiple linear regression. More importantly, optimized response parameters were generally similar among sites with varying hydrological conditions, suggesting generality to the functions. Model forms that included interacting responses to multiple forcing factors were more effective than were single response functions, indicating the principle of a single limiting factor is not correct in wetlands and both climatic and hydrological variables must be considered in predicting responses to hydrological or climate change.
Functional trait responses to grazing are mediated by soil moisture and plant functional group identity

PubMed Central

Zheng, Shuxia; Li, Wenhuai; Lan, Zhichun; Ren, Haiyan; Wang, Kaibo

2015-01-01

Abundant evidence has shown that grazing alters plant functional traits, community structure and ecosystem functioning of grasslands. Few studies, however, have tested how plant responses to grazing are mediated by resource availability and plant functional group identity. We examined the effects of grazing on functional traits across a broad range of species along a soil moisture gradient in Inner Mongolia grassland. Our results showed that trait syndromes of plant size (individual biomass) and shoot growth (leaf N content and leaf density) distinguished plant species responses to grazing. The effects of grazing on functional traits were mediated by soil moisture and dependent on functional group identity. For most species, grazing decreased plant height but increased leaf N and specific leaf area (SLA) along the moisture gradient. Grazing enhanced the community-weighted attributes (leaf NCWM and SLACWM), which were triggered mainly by the positive trait responses of annuals and biennials and perennial grasses, and increased relative abundance of perennial forbs. Our results suggest that grazing-induced species turnover and increased intraspecific trait variability are two drivers for the observed changes in community weighted attributes. The dominant perennial bunchgrasses exhibited mixed tolerance–resistance strategies to grazing and mixed acquisitive–conservative strategies in resource utilization. PMID:26655858
Functional trait responses to grazing are mediated by soil moisture and plant functional group identity.

PubMed

Zheng, Shuxia; Li, Wenhuai; Lan, Zhichun; Ren, Haiyan; Wang, Kaibo

2015-12-11

Abundant evidence has shown that grazing alters plant functional traits, community structure and ecosystem functioning of grasslands. Few studies, however, have tested how plant responses to grazing are mediated by resource availability and plant functional group identity. We examined the effects of grazing on functional traits across a broad range of species along a soil moisture gradient in Inner Mongolia grassland. Our results showed that trait syndromes of plant size (individual biomass) and shoot growth (leaf N content and leaf density) distinguished plant species responses to grazing. The effects of grazing on functional traits were mediated by soil moisture and dependent on functional group identity. For most species, grazing decreased plant height but increased leaf N and specific leaf area (SLA) along the moisture gradient. Grazing enhanced the community-weighted attributes (leaf NCWM and SLACWM), which were triggered mainly by the positive trait responses of annuals and biennials and perennial grasses, and increased relative abundance of perennial forbs. Our results suggest that grazing-induced species turnover and increased intraspecific trait variability are two drivers for the observed changes in community weighted attributes. The dominant perennial bunchgrasses exhibited mixed tolerance-resistance strategies to grazing and mixed acquisitive-conservative strategies in resource utilization.
Derived Manding in Children with Autism: Synthesizing Skinner's Verbal Behavior with Relational Frame Theory

PubMed Central

2005-01-01

Mand functions for two stimuli (A1 and A2) were trained for 3 children with autism and were then incorporated into two related conditional discriminations (A1-B1/A2 -B2 and B1-C1/B2-C2). Tests were conducted to probe for a derived transfer of mand response functions from A1 and A2 to C1 and C2, respectively. When 1 participant failed to demonstrate derived transfer of mand response functions, transfer training using exemplars was conducted. When participants had demonstrated derived transfer of mand functions, the X1 and X2 tokens that were employed as reinforcers for mand responses were incorporated into two conditional discriminations (X1-Y1/X2-Y2 and Y1-Z1/Y2-Z2). Tests were conducted for derived transfer of reinforcing functions. Finally, tests were conducted to determine if the participants would demonstrate derived manding for the derived reinforcers (present C1 and C2 to mand for Z1 and Z2, respectively). Derived transfer of functions was observed when the sequence of training and testing was reversed (i.e., training and testing reinforcing functions before mand response functions) and when only minimal instructions were provided. PMID:16463526
Effect of design selection on response surface performance

NASA Technical Reports Server (NTRS)

Carpenter, William C.

1993-01-01

The mathematical formulation of the engineering optimization problem is given. Evaluation of the objective function and constraint equations can be very expensive in a computational sense. Thus, it is desirable to use as few evaluations as possible in obtaining its solution. In solving the equation, one approach is to develop approximations to the objective function and/or restraint equations and then to solve the equation using the approximations in place of the original functions. These approximations are referred to as response surfaces. The desirability of using response surfaces depends upon the number of functional evaluations required to build the response surfaces compared to the number required in the direct solution of the equation without approximations. The present study is concerned with evaluating the performance of response surfaces so that a decision can be made as to their effectiveness in optimization applications. In particular, this study focuses on how the quality of approximations is effected by design selection. Polynomial approximations and neural net approximations are considered.

Research Review: altered reward function in adolescent depression: what, when and how?

PubMed

Forbes, Erika E; Dahl, Ronald E

2012-01-01

Conceptual models and recent evidence indicate that neural response to reward is altered in depression. Taking a developmental approach to investigating reward function in adolescent depression can elucidate the etiology, pathophysiology and course of depression, a disorder that typically begins during adolescence and has high rates of recurrence. This conceptual review describes the what, when and how of altered reward function in adolescent depression. With the goal of generating new, testable hypotheses within a developmental affective neuroscience framework, we critically review findings and suggest future directions. Peer-reviewed empirical papers for inclusion in this critical review were obtained by searching PubMed, PsycInfo and ScienceDirect for the years 1990-2010. A pattern of low striatal response and high medial prefrontal response to reward is evident in adolescents and adults with depression. Given the salience of social stimuli for positive affect and depression, reward function might be especially disrupted in response to social rewards. Because of changes in the dopamine system and reward function with aging, altered reward function in depression might be more evident during adolescence than later in life; however, low reward function may also be a stable characteristic of people who experience depression. Mechanisms of altered reward function in depression could include disrupted balance of corticostriatal circuit function, with disruption occurring as aberrant adolescent brain development. Future studies should examine responses to social rewards; employ longitudinal and prospective designs; and investigate patterns of functional connectivity in reward circuits. Understanding altered reward function in depression has potential implications for treatment development. A more rigorous approach to investigating anhedonia, threat-reward interactions and comorbid anxiety will be valuable to future progress in describing the role of reward function in the pathophysiology of depression. © 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.
The energy dependence of the lateral dose response functions of detectors with various densities in photon-beam dosimetry.

PubMed

Looe, Hui Khee; Harder, Dietrich; Poppe, Björn

2017-02-07

The lateral dose response function is a general characteristic of the volume effect of a detector used for photon dosimetry in a water phantom. It serves as the convolution kernel transforming the true absorbed dose to water profile, which would be produced within the undisturbed water phantom, into the detector-measured signal profile. The shape of the lateral dose response function characterizes (i) the volume averaging attributable to the detector's size and (ii) the disturbance of the secondary electron field associated with the deviation of the electron density of the detector material from the surrounding water. In previous work, the characteristic dependence of the shape of the lateral dose response function upon the electron density of the detector material was studied for 6 MV photons by Monte Carlo simulation of a wall-less voxel-sized detector (Looe et al 2015 Phys. Med. Biol. 60 6585-07). This study is here continued for 60 Co gamma rays and 15 MV photons in comparison with 6 MV photons. It is found (1) that throughout these photon spectra the shapes of the lateral dose response functions are retaining their characteristic dependence on the detector's electron density, and (2) that their energy-dependent changes are only moderate. This appears as a practical advantage because the lateral dose response function can then be treated as practically invariant across a clinical photon beam in spite of the known changes of the photon spectrum with increasing distance from the beam axis.
The Use of Dispersion Relations For The Geomagnetic Transfer Functions

NASA Astrophysics Data System (ADS)

Marcuello, A.; Queralt, P.; Ledo, J. J.

The magnetotelluric responses are complex magnitudes, where real and imaginary parts contain the same information on the geoelectrical structure. It seems possible, from very general hypotheses on the geoelectrical models (causality, stability and passivity), to apply the Kramers-Krönig dispersion relations to the magnetotelluric responses (impedance, geomagnetic transfer functions,...). In particular, the applica- bility of these relations to the impedance is a current point of discussion, but there are not many examples of their application to the geomagnetic transfer functions (tipper). The aim of this paper is to study how the relations of dispersion are applied to the real and imaginary part of the geomagnetic transfer functions, and to check its validity. For this reason, we have considered data (or responses) from two- and three-dimensional structures, and for these data, we have taken two situations: 1.- Responses that have been synthetically generated from numerical modelling, that allows us to control the quality of the data. 2.- Responses obtained from fieldwork, that are affected by exper- imental error. Additionally, we have also explored the use of these relations to extrap- olate the geomagnetic transfer functions outside the interval of measured frequencies, in order to obtain constrains on the values of these extrapolated data. The results have shown that the dispersion relations are accomplished for the geomag- netic transfer functions, and they can offer information about how these responses are behaved outside (but near) the range of measured frequencies.
Round window closure affects cochlear responses to suprathreshold stimuli.

PubMed

Cai, Qunfeng; Whitcomb, Carolyn; Eggleston, Jessica; Sun, Wei; Salvi, Richard; Hu, Bo Hua

2013-12-01

The round window acts as a vent for releasing inner ear pressure and facilitating basilar membrane vibration. Loss of this venting function affects cochlear function, which leads to hearing impairment. In an effort to identify functional changes that might be used in clinical diagnosis of round window atresia, the current investigation was designed to examine how the cochlea responds to suprathreshold stimuli following round window closure. Prospective, controlled, animal study. A rat model of round window occlusion (RWO) was established. With this model, the thresholds of auditory brainstem responses (ABR) and the input/output (IO) functions of distortion product otoacoustic emissions (DPOAEs) and acoustic startle responses were examined. Round window closure caused a mild shift in the thresholds of the auditory brainstem response (13.5 ± 9.1 dB). It also reduced the amplitudes of the distortion product otoacoustic emissions and the slope of the input/output functions. This peripheral change was accompanied by a significant reduction in the amplitude, but not the threshold, of the acoustic startle reflex, a motor response to suprathreshold sounds. In addition to causing mild increase in the threshold of the auditory brainstem response, round window occlusion reduced the slopes of both distortion product otoacoustic emissions and startle reflex input/output functions. These changes differ from those observed for typical conductive or sensory hearing loss, and could be present in patients with round window atresia. However, future clinical observations in patients are needed to confirm these findings. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.
Functional Response of Eretmocerus delhiensis on Trialeurodes vaporariorum by Parasitism and Host Feeding

PubMed Central

Ebrahimifar, Jafar; Allahyari, Hossein

2017-01-01

The parasitoid wasp, Eretmocerus delhiensis (Hymenoptera, Aphelinidae) is a thelytokous and syn-ovigenic parasitoid. To evaluate E. delhiensis as a biocontrol agent in greenhouse, the killing efficiency of this parasitoid by parasitism and host-feeding, were studied. Killing efficiency can be compared by estimation of functional response parameters. Laboratory experiments were performed in controllable conditions to evaluate the functional response of E. delhiensis at eight densities (2, 4, 8, 16, 32, 64, 100, and 120 third nymphal stage) of Trialeurodes vaporariorum (Hemiptera, Aleyrodidae) on two hosts including; tomato and prickly lettuce. The maximum likelihood estimates from regression logistic analysis revealed type II functional response for two host plants and the type of functional response was not affected by host plant. Roger’s model was used to fit the data. The attack rate (a) for E. delhiensis was 0.0286 and 0.0144 per hour on tomato and 0.0434 and 0.0170 per hour on prickly lettuce for parasitism and host feeding, respectively. Furthermore, estimated handling times (Th) were 0.4911 and 1.4453 h on tomato and 0.5713 and 1.5001 h on prickly lettuce for parasitism and host feeding, respectively. Based on 95% confidence interval, functional response parameters were significantly different between the host plants solely in parasitism. Results of this study opens new insight in the host parasitoid interactions, subsequently needs further investigation before utilizing it for management and reduction of greenhouse whitefly. PMID:28423420
Mechanisms of motor recovery after subtotal spinal cord injury: insights from the study of mice carrying a mutation (WldS) that delays cellular responses to injury.

PubMed

Zhang, Z; Guth, L; Steward, O

1998-01-01

Partial lesions of the mammalian spinal cord result in an immediate motor impairment that recovers gradually over time; however, the cellular mechanisms responsible for the transient nature of this paralysis have not been defined. A unique opportunity to identify those injury-induced cellular responses that mediate the recovery of function has arisen from the discovery of a unique mutant strain of mice in which the onset of Wallerian degeneration is dramatically delayed. In this strain of mice (designated WldS for Wallerian degeneration, slow), many of the cellular responses to spinal cord injury are also delayed. We have used this experimental animal model to evaluate possible causal relationships between these delayed cellular responses and the onset of functional recovery. For this purpose, we have compared the time course of locomotor recovery in C57BL/6 (control) mice and in WldS (mutant) mice by hemisecting the spinal cord at T8 and evaluating locomotor function at daily postoperative intervals. The time course of locomotor recovery (as determined by the Tarlov open-field walking procedure) was substantially delayed in mice carrying the WldS mutation: C57BL/6 control mice began to stand and walk within 6 days (mean Tarlov score of 4), whereas mutant mice did not exhibit comparable locomotor function until 16 days postoperatively. (a) The rapid return of locomotor function in the C57BL/6 mice suggests that the recovery resulted from processes of functional plasticity rather than from regeneration or collateral sprouting of nerve fibers. (b) The marked delay in the return of locomotor function in WldS mice indicates that the processes of neuroplasticity are induced by degenerative changes in the damaged neurons. (c) These strains of mice can be effectively used in future studies to elucidate the specific biochemical and physiological alterations responsible for inducing functional plasticity and restoring locomotor function after spinal cord injury.
A functional neuroimaging review of obesity, appetitive hormones and ingestive behavior.

PubMed

Burger, Kyle S; Berner, Laura A

2014-09-01

Adequate energy intake is vital for the survival of humans and is regulated by complex homeostatic and hedonic mechanisms. Supported by functional MRI (fMRI) studies that consistently demonstrate differences in brain response as a function of weight status during exposure to appetizing food stimuli, it has been posited that hedonically driven food intake contributes to weight gain and obesity maintenance. These food reward theories of obesity are reliant on the notion that the aberrant brain response to food stimuli relates directly to ingestive behavior, specifically, excess food intake. Importantly, functioning of homeostatic neuroendocrine regulators of food intake, such as leptin and ghrelin, are impacted by weight status. Thus, data from studies that evaluate the effect on weight status on brain response to food may be a result of differences in neuroendocrine functioning and/or behavior. In the present review, we examine the influence of weight and weight change, exogenous administration of appetitive hormones, and ingestive behavior on BOLD response to food stimuli. Published by Elsevier Inc.
Characterization of nonGaussian atmospheric turbulence for prediction of aircraft response statistics

NASA Technical Reports Server (NTRS)

Mark, W. D.

1977-01-01

Mathematical expressions were derived for the exceedance rates and probability density functions of aircraft response variables using a turbulence model that consists of a low frequency component plus a variance modulated Gaussian turbulence component. The functional form of experimentally observed concave exceedance curves was predicted theoretically, the strength of the concave contribution being governed by the coefficient of variation of the time fluctuating variance of the turbulence. Differences in the functional forms of response exceedance curves and probability densities also were shown to depend primarily on this same coefficient of variation. Criteria were established for the validity of the local stationary assumption that is required in the derivations of the exceedance curves and probability density functions. These criteria are shown to depend on the relative time scale of the fluctuations in the variance, the fluctuations in the turbulence itself, and on the nominal duration of the relevant aircraft impulse response function. Metrics that can be generated from turbulence recordings for testing the validity of the local stationary assumption were developed.
Method for suppressing noise in measurements

NASA Technical Reports Server (NTRS)

Carson, Paul L. (Inventor); Madsen, Louis A. (Inventor); Leskowitz, Garett M. (Inventor); Weitekamp, Daniel P. (Inventor)

2000-01-01

Methods for suppressing noise in measurements by correlating functions based on at least two different measurements of a system at two different times. In one embodiment, a measurement operation is performed on at least a portion of a system that has a memory. A property of the system is measured during a first measurement period to produce a first response indicative of a first state of the system. Then the property of the system is measured during a second measurement period to produce a second response indicative of a second state of the system. The second measurement is performed after an evolution duration subsequent to the first measurement period when the system still retains a degree of memory of an aspect of the first state. Next, a first function of the first response is combined with a second function of the second response to form a second-order correlation function. Information of the system is then extracted from the second-order correlation function.
Transforming Water: Social Influence Moderates Psychological, Physiological, and Functional Response to a Placebo Product

PubMed Central

Crum, Alia J.; Phillips, Damon J.; Goyer, J. Parker; Akinola, Modupe; Higgins, E. Tory

2016-01-01

This paper investigates how social influence can alter physiological, psychological, and functional responses to a placebo product and how such responses influence the ultimate endorsement of the product. Participants consumed a product, “AquaCharge Energy Water,” falsely-labeled as containing 200 mg of caffeine but which was actually plain spring water, in one of three conditions: a no social influence condition, a disconfirming social influence condition, and a confirming social influence condition. Results demonstrated that the effect of the product labeling on physiological alertness (systolic blood pressure), psychological alertness (self-reported alertness), functional alertness (cognitive interference), and product endorsement was moderated by social influence: participants experienced more subjective, physiological and functional alertness and stronger product endorsement when they consumed the product in the confirming social influence condition than when they consumed the product in the disconfirming social influence condition. These results suggest that social influence can alter subjective, physiological, and functional responses to a faux product, in this case transforming the effects of plain water. PMID:27875567
Transforming Water: Social Influence Moderates Psychological, Physiological, and Functional Response to a Placebo Product.

PubMed

Crum, Alia J; Phillips, Damon J; Goyer, J Parker; Akinola, Modupe; Higgins, E Tory

2016-01-01

This paper investigates how social influence can alter physiological, psychological, and functional responses to a placebo product and how such responses influence the ultimate endorsement of the product. Participants consumed a product, "AquaCharge Energy Water," falsely-labeled as containing 200 mg of caffeine but which was actually plain spring water, in one of three conditions: a no social influence condition, a disconfirming social influence condition, and a confirming social influence condition. Results demonstrated that the effect of the product labeling on physiological alertness (systolic blood pressure), psychological alertness (self-reported alertness), functional alertness (cognitive interference), and product endorsement was moderated by social influence: participants experienced more subjective, physiological and functional alertness and stronger product endorsement when they consumed the product in the confirming social influence condition than when they consumed the product in the disconfirming social influence condition. These results suggest that social influence can alter subjective, physiological, and functional responses to a faux product, in this case transforming the effects of plain water.
A Functional Toll-Interacting Protein Variant Is Associated with Bacillus Calmette-Guérin-Specific Immune Responses and Tuberculosis.

PubMed

Shah, Javeed A; Musvosvi, Munyaradzi; Shey, Muki; Horne, David J; Wells, Richard D; Peterson, Glenna J; Cox, Jeffery S; Daya, Michelle; Hoal, Eileen G; Lin, Lin; Gottardo, Raphael; Hanekom, Willem A; Scriba, Thomas J; Hatherill, Mark; Hawn, Thomas R

2017-08-15

The molecular mechanisms that regulate tuberculosis susceptibility and bacillus Calmette-Guérin (BCG)-induced immunity are mostly unknown. However, induction of the adaptive immune response is a critical step in host control of Mycobacterium tuberculosis. Toll-interacting protein (TOLLIP) is a ubiquitin-binding protein that regulates innate immune responses, including Toll-like receptor signaling, which initiate adaptive immunity. TOLLIP variation is associated with susceptibility to tuberculosis, but the mechanism by which it regulates tuberculosis immunity is poorly understood. To identify functional TOLLIP variants and evaluate the role of TOLLIP variation on innate and adaptive immune responses to mycobacteria and susceptibility to tuberculosis. We used human cellular immunology approaches to characterize the role of a functional TOLLIP variant on monocyte mRNA expression and M. tuberculosis-induced monocyte immune functions. We also examined the association of TOLLIP variation with BCG-induced T-cell responses and susceptibility to latent tuberculosis infection. We identified a functional TOLLIP promoter region single-nucleotide polymorphism, rs5743854, which was associated with decreased TOLLIP mRNA expression in infant monocytes. After M. tuberculosis infection, TOLLIP-deficient monocytes demonstrated increased IL-6, increased nitrite, and decreased bacterial replication. The TOLLIP-deficiency G/G genotype was associated with decreased BCG-specific IL-2 + CD4 + T-cell frequency and proliferation. This genotype was also associated with increased susceptibility to latent tuberculosis infection. TOLLIP deficiency is associated with decreased BCG-specific T-cell responses and increased susceptibility to tuberculosis. We hypothesize that the heightened antibacterial monocyte responses after vaccination of TOLLIP-deficient infants are responsible for decreased BCG-specific T-cell responses. Activating TOLLIP may provide a novel adjuvant strategy for BCG vaccination.
Functional plasticity of regenerated and intact taste receptors in adult rats unmasked by dietary sodium restriction.

PubMed

Hill, D L; Phillips, L M

1994-05-01

Unilateral chorda tympani nerve sectioning was combined with institution of a sodium-restricted diet in adult rats to determine the role that environment has on the functional properties of regenerating taste receptor cells. Rats receiving chorda tympani sectioning but no dietary manipulation (cut controls) and rats receiving only the dietary manipulation (diet controls) had normal responses to a concentration series of NaCl, sodium acetate (NaAc), and NH4Cl. However, responses from the regenerated nerve in NaCl-restricted rats (40-120 d postsectioning) to NaCl and NaAc were reduced by as much as 30% compared to controls, indicating that regenerating taste receptors are influenced by environmental (dietary) factors. Responses to NH4Cl were normal; therefore, the effect appears specific to sodium salts. Surprisingly, in the same rats, NaCl responses from the contralateral, intact chorda tympani were up to 40% greater than controls. Thus, in the same rat, there was over a twofold difference in sodium responses between the right and left chorda tympani nerves. A study of the time course of the functional alterations in the intact nerve revealed that responses to NaCl were extremely low immediately following sectioning (about 20% of the normal response), and then increased monotonically during the following 50 d until relative response magnitudes became supersensitive. This function occurred even when the cut chorda tympani was prevented from reinnervating lingual epithelia, demonstrating that events related to regeneration do not play a role in the functional properties of the contralateral side of the tongue.(ABSTRACT TRUNCATED AT 250 WORDS)
A SAL1 Loss-of-Function Arabidopsis Mutant Exhibits Enhanced Cadmium Tolerance in Association with Alleviation of Endoplasmic Reticulum Stress.

PubMed

Xi, Hongmei; Xu, Hua; Xu, Wenxiu; He, Zhenyan; Xu, Wenzhong; Ma, Mi

2016-06-01

SAL1, as a negative regulator of stress response signaling, has been studied extensively for its role in plant response to environmental stresses. However, the role of SAL1 in cadmium (Cd) stress response and the underlying mechanism is still unclear. Using an Arabidopsis thaliana loss-of-function mutant of SAL1, we assessed Cd resistance and further explored the Cd toxicity mechanism through analysis of the endoplasmic reticulum (ER) stress response. The loss of SAL1 function greatly improved Cd tolerance and significantly attenuated ER stress in Arabidopsis. Exposure to Cd induced an ER stress response in Arabidopsis as evidenced by unconventional splicing of AtbZIP60 and up-regulation of ER stress-responsive genes. Damage caused by Cd was markedly reduced in the ER stress response double mutant bzip28 bzip60 or by application of the ER stress-alleviating chemical agents, tauroursodeoxycholic acid (TUDCA) and 4-phenyl butyric acid (4-PBA), in wild-type plants. The Cd-induced ER stress in Arabidopsis was also alleviated by loss of function of SAL1. These results identified SAL1 as a new component mediating Cd toxicity and established the role of the ER stress response in Cd toxicity. Additionally, the attenuated ER stress in the sal1 mutant might also shed new light on the mechanism of diverse abiotic stress resistance in the SAL1 loss-of-function mutants. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.
The relationship between functional capacity and community responsibilities in middle-aged and older Latinos of Mexican origin with chronic psychosis.

PubMed

Cardenas, Veronica; Mausbach, Brent T; Barrio, Concepcion; Bucardo, Jesus; Jeste, Dilip; Patterson, Thomas

2008-01-01

The purpose of this study was to examine the relationship between scores on the UCSD Performance-based Skills Assessment (UPSA), a performance-based measure of functional capacity, and level of patient community responsibilities (i.e., work for pay; volunteer work; attend school; household duties) in a Latino sample. Participants were 58 middle-aged and older Latinos of Mexican origin (mean age=48.8 years) with a diagnosis of schizophrenia or schizoaffective disorder. We conducted an analysis of covariance (ANCOVA), controlling for age, symptoms of psychosis, and participant language, to determine if greater participation in community responsibilities was associated with higher functional capacity, as measured by the UPSA. Results indicated significant group differences in UPSA scores (F=5.11, df=2, 51; p=.009), with patients reporting only a single community responsibility having significantly higher UPSA scores than those reporting zero community responsibilities (p=.016) and those reporting two responsibilities scoring significantly higher than those reporting zero community responsibility (p=.008). There were no differences found between those reporting one and those reporting two community responsibilities (p=.256). In contrast, no group differences were observed on the Dementia Rating Scale, a global measure of cognitive functioning (F=2.14, df=2, 51; p=.128). These results provide initial support for the validity of the UPSA in Latino patients of Mexican origin, and suggest that improvement in functional capacity (i.e., UPSA scores) may be associated with increased capacity for greater community involvement in this population.
The Relationship between Functional Capacity and Community Responsibilities in Middle-aged and Older Latinos of Mexican Origin with Chronic Psychosis

PubMed Central

Cardenas, Veronica; Mausbach, Brent T.; Barrio, Concepcion; Bucardo, Jesus; Jeste, Dilip; Patterson, Thomas

2008-01-01

The purpose of this study was to examine the relationship between scores on the UCSD Performance-based Skills Assessment (UPSA), a performance-based measure of functional capacity, and level of patient community responsibilities (i.e., work for pay; volunteer work; attend school; household duties) in a Latino sample. Participants were 58 middle-aged and older Latinos of Mexican origin (mean age = 48.8 years) with a diagnosis of schizophrenia or schizoaffective disorder. We conducted an analysis of covariance (ANCOVA), controlling for age, symptoms of psychosis, and participant language, to determine if greater participation in community responsibilities was associated with higher functional capacity, as measured by the UPSA. Results indicated significant group differences in UPSA scores (F = 5.11, df = 2,51; p = .009), with patients reporting only a single community responsibility having significantly higher UPSA scores than those reporting zero community responsibilities (p = .016) and those reporting two responsibilities scoring significantly higher than those reporting zero community responsibility (p = .008). There were no differences found between those reporting one and those reporting two community responsibilities (p= .256). In contrast, no group differences were observed on the Dementia Rating Scale, a global measure of cognitive functioning (F = 2.14, df = 2,51; p = .128). These results provide initial support for the validity of the UPSA in Latino patients of Mexican origin, and suggest that improvement in functional capacity (i.e., UPSA scores) may be associated with increased capacity for greater community involvement in this population. PMID:17936585
A Bifactor Multidimensional Item Response Theory Model for Differential Item Functioning Analysis on Testlet-Based Items

ERIC Educational Resources Information Center

Fukuhara, Hirotaka; Kamata, Akihito

2011-01-01

A differential item functioning (DIF) detection method for testlet-based data was proposed and evaluated in this study. The proposed DIF model is an extension of a bifactor multidimensional item response theory (MIRT) model for testlets. Unlike traditional item response theory (IRT) DIF models, the proposed model takes testlet effects into…
Dissociating Consciousness from Inhibitory Control: Evidence for Unconsciously Triggered Response Inhibition in the Stop-Signal Task

ERIC Educational Resources Information Center

van Gaal, Simon; Ridderinkhof, K. Richard; van den Wildenberg, Wery P. M.; Lamme, Victor A. F.

2009-01-01

Theories about the functional relevance of consciousness commonly posit that higher order cognitive control functions, such as response inhibition, require consciousness. To test this assertion, the authors designed a masked stop-signal paradigm to examine whether response inhibition could be triggered and initiated by masked stop signals, which…
The Role of Expectancy in Eliciting Hypnotic Responses as a Function of Type of Induction.

ERIC Educational Resources Information Center

Kirsch, Irving; And Others

1984-01-01

Examined the relationship between expectancy and suggestibility in hypnosis as a function of type of induction (N=100). Results showed subjects were able to predict their responses to a cognitive skill induction with great accuracy but were not very accurate in predicting responses to a hypnotic trance induction. (JAC)
Sensory Responsiveness as a Predictor of Social Severity in Children with High Functioning Autism Spectrum Disorders

ERIC Educational Resources Information Center

Hilton, Claudia L.; Harper, Jacquelyn D.; Kueker, Rachel Holmes; Lang, Andrea Runzi; Abbacchi, Anna M.; Todorov, Alexandre; LaVesser, Patricia D.

2010-01-01

This study examines the relationship between sensory responsiveness and social severity in children with high functioning autism spectrum disorders (HFASD; N = 36) and age-matched controls (N = 26) between 6 and 10 years old. Significant relationships were found between social responsiveness scale scores and each of the six sensory profile sensory…

Feedback Functions, Optimization, and the Relation of Response Rate to Reinforcer Rate

ERIC Educational Resources Information Center

Soto, Paul L.; McDowell, Jack J.; Dallery, Jesse

2006-01-01

The present experiment arranged a series of inverted U-shaped feedback functions relating reinforcer rate to response rate to test whether responding was consistent with an optimization account or with a one-to-one relation of response rate to reinforcer rate such as linear system theory's rate equation or Herrnstein's hyperbola. Reinforcer rate…
Teachers' Perceptions of the Functionality and Effectiveness of the Response to Intervention Model

ERIC Educational Resources Information Center

Hernandez, Patricia

2012-01-01

The purpose of this study is to investigate teachers' perceptions of the functionality and effectiveness of the response to intervention model. Using a response to intervention (RTI) framework has become a priority for school district as they move to meet federal legislative mandates. Through this study teachers in the southwestern part of the…
Partially Testing a Process Model for Understanding Victim Responses to an Anticipated Worksite Closure

ERIC Educational Resources Information Center

Blau, Gary

2007-01-01

This study partially tested a recent process model for understanding victim responses to worksite/function closure (W/FC) proposed by Blau [Blau, G. (2006). A process model for understanding victim responses to worksite/function closure. "Human Resource Management Review," 16, 12-28], in a pharmaceutical manufacturing site. Central to the model…
Nonlinear response from transport theory and quantum field theory at finite temperature

NASA Astrophysics Data System (ADS)

Carrington, M. E.; Defu, Hou; Kobes, R.

2001-07-01

We study the nonlinear response in weakly coupled hot φ4 theory. We obtain an expression for a quadratic shear viscous response coefficient using two different formalisms: transport theory and response theory. The transport theory calculation is done by assuming a local equilibrium form for the distribution function and expanding in the gradient of the local four dimensional velocity field. By performing a Chapman-Enskog expansion on the Boltzmann equation we obtain a hierarchy of equations for the coefficients of the expanded distribution function. To do the response theory calculation we use Zubarev's techniques in nonequilibrium statistical mechanics to derive a generalized Kubo formula. Using this formula allows us to obtain the quadratic shear viscous response from the three-point retarded Green function of the viscous shear stress tensor. We use the closed time path formalism of real time finite temperature field theory to show that this three-point function can be calculated by writing it as an integral equation involving a four-point vertex. This four-point vertex can in turn be obtained from an integral equation which represents the resummation of an infinite series of ladder and extended-ladder diagrams. The connection between transport theory and response theory is made when we show that the integral equation for this four-point vertex has exactly the same form as the equation obtained from the Boltzmann equation for the coefficient of the quadratic term of the gradient expansion of the distribution function. We conclude that calculating the quadratic shear viscous response using transport theory and keeping terms that are quadratic in the gradient of the velocity field in the Chapman-Enskog expansion of the Boltzmann equation is equivalent to calculating the quadratic shear viscous response from response theory using the next-to-linear response Kubo formula, with a vertex given by an infinite resummation of ladder and extended-ladder diagrams.
Awake vs. anesthetized: layer-specific sensory processing in visual cortex and functional connectivity between cortical areas

PubMed Central

Sellers, Kristin K.; Bennett, Davis V.; Hutt, Axel; Williams, James H.

2015-01-01

During general anesthesia, global brain activity and behavioral state are profoundly altered. Yet it remains mostly unknown how anesthetics alter sensory processing across cortical layers and modulate functional cortico-cortical connectivity. To address this gap in knowledge of the micro- and mesoscale effects of anesthetics on sensory processing in the cortical microcircuit, we recorded multiunit activity and local field potential in awake and anesthetized ferrets (Mustela putoris furo) during sensory stimulation. To understand how anesthetics alter sensory processing in a primary sensory area and the representation of sensory input in higher-order association areas, we studied the local sensory responses and long-range functional connectivity of primary visual cortex (V1) and prefrontal cortex (PFC). Isoflurane combined with xylazine provided general anesthesia for all anesthetized recordings. We found that anesthetics altered the duration of sensory-evoked responses, disrupted the response dynamics across cortical layers, suppressed both multimodal interactions in V1 and sensory responses in PFC, and reduced functional cortico-cortical connectivity between V1 and PFC. Together, the present findings demonstrate altered sensory responses and impaired functional network connectivity during anesthesia at the level of multiunit activity and local field potential across cortical layers. PMID:25833839
A mathematical function for the description of nutrient-response curve

PubMed Central

Ahmadi, Hamed

2017-01-01

Several mathematical equations have been proposed to modeling nutrient-response curve for animal and human justified on the goodness of fit and/or on the biological mechanism. In this paper, a functional form of a generalized quantitative model based on Rayleigh distribution principle for description of nutrient-response phenomena is derived. The three parameters governing the curve a) has biological interpretation, b) may be used to calculate reliable estimates of nutrient response relationships, and c) provide the basis for deriving relationships between nutrient and physiological responses. The new function was successfully applied to fit the nutritional data obtained from 6 experiments including a wide range of nutrients and responses. An evaluation and comparison were also done based simulated data sets to check the suitability of new model and four-parameter logistic model for describing nutrient responses. This study indicates the usefulness and wide applicability of the new introduced, simple and flexible model when applied as a quantitative approach to characterizing nutrient-response curve. This new mathematical way to describe nutritional-response data, with some useful biological interpretations, has potential to be used as an alternative approach in modeling nutritional responses curve to estimate nutrient efficiency and requirements. PMID:29161271
Analysis of space vehicle structures using the transfer-function concept

NASA Technical Reports Server (NTRS)

Heer, E.; Trubert, M. R.

1969-01-01

Analysis of large complex systems is accomplished by dividing it into suitable subsystems and determining the individual dynamical and vibrational responses. Frequency transfer functions then determine the vibrational response of the whole system.
Differential responses to guano fertilization among tropical tree species with varying functional traits.

PubMed

Young, Hillary S; McCauley, Douglas J; Dirzo, Rodolfo

2011-02-01

Seabirds often cause significant changes to soil properties, and seabird-dominated systems often host unique plant communities. This study experimentally (1) examined species-specific responses to seabird guano gradients, (2) considered the role that differential functional traits among species play in altering plant response to guano, and (3) investigated the implications of seabird guano on range-expanding species. Using a greenhouse fertilization experiment, we examined how guano fertilization affects the growth and functional traits of four tree species dominant in the Pacific Islands: Cocos nucifera, Pisonia grandis, Scaevola sericea, and Tournefortia argentea. In these systems, seabirds are frequently found in association with three of these four species; the remaining species, C. nucifera, is a recently proliferating species commonly found in the region but rarely associated with seabirds. We determined that responses to guano addition differed significantly between species in ways that were consistent with predictions based on differing functional traits among species. Notably, we demonstrated that C. nucifera showed no growth responses to guano additions, whereas all seabird-associated plants showed strong responses. These results provide experimental evidence of differential species response to guano additions, suggesting that differences in species functional traits may contribute to changes in plant communities in seabird-dominated areas, with seabird-associated species garnering performance advantages in these high-nutrient environments. Among these species, results also suggest that C. nucifera may have a competitive advantage in low-nutrient environments, providing an unusual example of how a range-expanding plant species can profit from low-nutrient environments.
Do Quercus ilex woodlands undergo abrupt non-linear functional changes in response to human disturbance along a climatic gradient?

NASA Astrophysics Data System (ADS)

Bochet, Esther; García-Fayos, Patricio; José Molina, Maria; Moreno de las Heras, Mariano; Espigares, Tíscar; Nicolau, Jose Manuel; Monleon, Vicente

2017-04-01

Theoretical models predict that drylands are particularly prone to suffer critical transitions with abrupt non-linear changes in their structure and functions as a result of the existing complex interactions between climatic fluctuations and human disturbances. However, so far, few studies provide empirical data to validate these models. We aim at determining how holm oak (Quercus ilex) woodlands undergo changes in their functions in response to human disturbance along an aridity gradient (from semi-arid to sub-humid conditions), in eastern Spain. For that purpose, we used (a) remote-sensing estimations of precipitation-use-efficiency (PUE) from enhanced vegetation index (EVI) observations performed in 231x231 m plots of the Moderate Resolution Imaging Spectroradiometer (MODIS); (b) biological and chemical soil parameter determinations (extracellular soil enzyme activity, soil respiration, nutrient cycling processes) from soil sampled in the same plots; (c) vegetation parameter determinations (ratio of functional groups) from vegetation surveys performed in the same plots. We analyzed and compared the shape of the functional change (in terms of PUE and soil and vegetation parameters) in response to human disturbance intensity for our holm oak sites along the aridity gradient. Overall, our results evidenced important differences in the shape of the functional change in response to human disturbance between climatic conditions. Semi-arid areas experienced a more accelerated non-linear decrease with an increasing disturbance intensity than sub-humid ones. The proportion of functional groups (herbaceous vs. woody cover) played a relevant role in the shape of the functional response of the holm oak sites to human disturbance.
COMBINE genetics study: the pharmacogenetics of alcoholism treatment response: genes and mechanisms.

PubMed

Goldman, David; Oroszi, Gabor; O'Malley, Stephanie; Anton, Raymond

2005-07-01

Partial efficacy of treatment and differences in adverse events across individuals are a challenge and an opportunity in the treatment of alcoholism. Individuation of therapy and understanding origins of differential treatment response may require identification of inherited functional variants of genes. The neurobiology of reward, executive cognitive function, anxiety and dysphoria have been identified as critical domains that may have a genetic basis that could predict treatment response. The COMBINE Study presents a unique opportunity to evaluate specific genetic loci (markers) that affect neurobiology central to addiction and extended withdrawal. The study also addresses variation in drug metabolism and action. Candidate genetic markers are selected for study based on functionality and abundance. COMT Vall58Met is a common (minor allele frequency 0.42), functional, catecholamine-metabolizing enzyme polymorphism with threefold relevance. Vall58Met alters executive cognitive function, stress and anxiety responses and brain endogenous opioid function. OPRM1 Asn40Asp is a common (minor allele frequency 0.10), functional polymorphism of the mu-opioid receptor, which may serve as a gatekeeper molecule in naltrexone's actions and was recently reported to affect naltrexone response. HTTLPR (minor allele frequency 0.40) alters serotonin transporter function to affect anxiety, dysphoria and obsessional behavior, which are assessed in COMBINE and may be related to relapse and addictive behavior. All genetic testing is consented through a separate human research protocol, and the testing is conducted nonclinically, confidentially and apart from the clinical record to protect human research participants who have volunteered for this aspect of COMBINE.
Sexually dimorphic functional connectivity in response to high vs. low energy-dense food cues in obese humans: an fMRI study.

PubMed

Atalayer, Deniz; Pantazatos, Spiro P; Gibson, Charlisa D; McOuatt, Haley; Puma, Lauren; Astbury, Nerys M; Geliebter, Allan

2014-10-15

Sexually-dimorphic behavioral and biological aspects of human eating have been described. Using psychophysiological interaction (PPI) analysis, we investigated sex-based differences in functional connectivity with a key emotion-processing region (amygdala, AMG) and a key reward-processing area (ventral striatum, VS) in response to high vs. low energy-dense (ED) food images using blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) in obese persons in fasted and fed states. When fed, in response to high vs. low-ED food cues, obese men (vs. women) had greater functional connectivity with AMG in right subgenual anterior cingulate, whereas obese women had greater functional connectivity with AMG in left angular gyrus and right primary motor areas. In addition, when fed, AMG functional connectivity with pre/post-central gyrus was more associated with BMI in women (vs. men). When fasted, obese men (vs. women) had greater functional connectivity with AMG in bilateral supplementary frontal and primary motor areas, left precuneus, and right cuneus, whereas obese women had greater functional connectivity with AMG in left inferior frontal gyrus, right thalamus, and dorsomedial prefrontal cortex. When fed, greater functional connectivity with VS was observed in men in bilateral supplementary and primary motor areas, left postcentral gyrus, and left precuneus. These sex-based differences in functional connectivity in response to visual food cues may help partly explain differential eating behavior, pathology prevalence, and outcomes in men and women. Published by Elsevier Inc.
ERP Responses to Violations in the Hierarchical Structure of Functional Categories in Japanese Verb Conjugation

ERIC Educational Resources Information Center

Kobayashi, Yuki; Sugioka, Yoko; Ito, Takane

2018-01-01

An event-related potential experiment was conducted in order to investigate readers' response to violations in the hierarchical structure of functional categories in Japanese, an agglutinative language where functional heads like Negation (Neg) as well as Tense (Tns) are realized as suffixes. A left-lateralized negativity followed by a P600 was…
Using Cochran's Z Statistic to Test the Kernel-Smoothed Item Response Function Differences between Focal and Reference Groups

ERIC Educational Resources Information Center

Zheng, Yinggan; Gierl, Mark J.; Cui, Ying

2010-01-01

This study combined the kernel smoothing procedure and a nonparametric differential item functioning statistic--Cochran's Z--to statistically test the difference between the kernel-smoothed item response functions for reference and focal groups. Simulation studies were conducted to investigate the Type I error and power of the proposed…
Models of subjective response to in-flight motion data

NASA Technical Reports Server (NTRS)

Rudrapatna, A. N.; Jacobson, I. D.

1973-01-01

Mathematical relationships between subjective comfort and environmental variables in an air transportation system are investigated. As a first step in model building, only the motion variables are incorporated and sensitivities are obtained using stepwise multiple regression analysis. The data for these models have been collected from commercial passenger flights. Two models are considered. In the first, subjective comfort is assumed to depend on rms values of the six-degrees-of-freedom accelerations. The second assumes a Rustenburg type human response function in obtaining frequency weighted rms accelerations, which are used in a linear model. The form of the human response function is examined and the results yield a human response weighting function for different degrees of freedom.
Effect of dolutegravir functional monotherapy on HIV-1 virological response in integrase strand transfer inhibitor resistant patients.

PubMed

Naeger, Lisa K; Harrington, Patrick; Komatsu, Takashi; Deming, Damon

2016-01-01

VIKING-4 assessed the safety and efficacy of dolutegravir in heavily antiretroviral treatment-experienced patients who had documented integrase strand transfer inhibitor (INSTI) resistance-associated substitutions in their HIV. VIKING-4 had a placebo-controlled 7-day dolutegravir functional monotherapy phase followed by dolutegravir plus an optimized background regimen for 48 weeks. Independent resistance analyses evaluated week 48 virological responses in the VIKING-4 trial based on the presence of baseline INSTI resistance-associated substitutions and baseline dolutegravir phenotypic susceptibility. Response rates at week 48 based on baseline dolutegravir resistance subgroups were compared for the 7-day dolutegravir functional monotherapy arm and placebo-control arm. Additionally, genotypic and phenotypic resistance at day 8 and time of failure was analysed for the virological failures from both arms. Week 48 response rates for VIKING-4 were 23% (3/13) in the 7-day dolutegravir functional monotherapy arm compared with 60% (9/15) in the 7-day placebo arm. Response rates were consistently lower in the dolutegravir functional monotherapy arm across baseline INSTI genotypic and phenotypic subgroups. There was a higher proportion of virological failures in the 7-day dolutegravir functional monotherapy arm (n=6/13; 46%) compared with the 7-day placebo arm (n=3/15; 20%). Additionally, five virological failures in the dolutegravir arm had virus expressing emergent INSTI resistance-associated substitutions compared with two in the placebo arm. Analysis of response rates and resistance emergence in VIKING-4 suggests careful consideration should be given to the duration of functional monotherapy in future studies of highly treatment-experienced patients to reduce the risk of resistance and virological failure.
Comparison of the functional rating index and the 18-item Roland-Morris Disability Questionnaire: responsiveness and reliability.

PubMed

Chansirinukor, Wunpen; Maher, Christopher G; Latimer, Jane; Hush, Julia

2005-01-01

Retrospective design. To compare the responsiveness and test-retest reliability of the Functional Rating Index and the 18-item version of the Roland-Morris Disability Questionnaire in detecting change in disability in patients with work-related low back pain. Many low back pain-specific disability questionnaires are available, including the Functional Rating Index and the 18-item version of the Roland-Morris Disability Questionnaire. No previous study has compared the responsiveness and reliability of these questionnaires. Files of patients who had been treated for work-related low back pain at a physical therapy clinic were reviewed, and those containing initial and follow-up Functional Rating Index and 18-item Roland-Morris Disability Questionnaires were selected. The responsiveness of both questionnaires was compared using two different methods. First, using the assumption that patients receiving treatment improve over time, various responsiveness coefficients were calculated. Second, using change in work status as an external criterion to identify improved and nonimproved patients, Spearman's rho and receiver operating characteristic curves were calculated. Reliability was estimated from the subset of patients who reported no change in their condition over this period and expressed with the intraclass correlation coefficient and the minimal detectable change. One hundred and forty-three patient files were retrieved. The responsiveness coefficients for the Functional Rating Index were greater than for the 18-item Roland-Morris Disability Questionnaire. The intraclass correlation coefficient values for both questionnaires calculated from 96 patient files were similar, but the minimal detectable change for the Functional Rating Index was less than for the 18-item Roland-Morris Disability Questionnaire. The Functional Rating Index seems preferable to the 18-item Roland-Morris Disability Questionnaire for use in clinical trials and clinical practice.
Reactivity of hemodynamic responses and functional connectivity to different states of alpha synchrony: a concurrent EEG-fMRI study.

PubMed

Wu, Lei; Eichele, Tom; Calhoun, Vince D

2010-10-01

Concurrent EEG-fMRI studies have provided increasing details of the dynamics of intrinsic brain activity during the resting state. Here, we investigate a prominent effect in EEG during relaxed resting, i.e. the increase of the alpha power when the eyes are closed compared to when the eyes are open. This phenomenon is related to changes in thalamo-cortical and cortico-cortical synchronization. In order to investigate possible changes to EEG-fMRI coupling and fMRI functional connectivity during the two states we adopted a data-driven approach that fuses the multimodal data on the basis of parallel ICA decompositions of the fMRI data in the spatial domain and of the EEG data in the spectral domain. The power variation of a posterior alpha component was used as a reference function to deconvolve the hemodynamic responses from occipital, frontal, temporal, and subcortical fMRI components. Additionally, we computed the functional connectivity between these components. The results showed widespread alpha hemodynamic responses and high functional connectivity during eyes-closed (EC) rest, while eyes open (EO) resting abolished many of the hemodynamic responses and markedly decreased functional connectivity. These data suggest that generation of local hemodynamic responses is highly sensitive to state changes that do not involve changes of mental effort or awareness. They also indicate the localized power differences in posterior alpha between EO and EC in resting state data are accompanied by spatially widespread amplitude changes in hemodynamic responses and inter-regional functional connectivity, i.e. low frequency hemodynamic signals display an equivalent of alpha reactivity. Copyright 2010 Elsevier Inc. All rights reserved.
Thermo-responsive cell culture carrier: Effects on macrophage functionality and detachment efficiency.

PubMed

Rennert, Knut; Nitschke, Mirko; Wallert, Maria; Keune, Natalie; Raasch, Martin; Lorkowski, Stefan; Mosig, Alexander S

2017-01-01

Harvesting cultivated macrophages for tissue engineering purposes by enzymatic digestion of cell adhesion molecules can potentially result in unintended activation, altered function, or behavior of these cells. Thermo-responsive polymer is a promising tool that allows for gentle macrophage detachment without artificial activation prior to subculture within engineered tissue constructs. We therefore characterized different species of thermo-responsive polymers for their suitability as cell substrate and to mediate gentle macrophage detachment by temperature shift. Primary human monocyte- and THP-1-derived macrophages were cultured on thermo-responsive polymers and characterized for phagocytosis and cytokine secretion in response to lipopolysaccharide stimulation. We found that both cell types differentially respond in dependence of culture and stimulation on thermo-responsive polymers. In contrast to THP-1 macrophages, primary monocyte-derived macrophages showed no signs of impaired viability, artificial activation, or altered functionality due to culture on thermo-responsive polymers compared to conventional cell culture. Our study demonstrates that along with commercially available UpCell carriers, two other thermo-responsive polymers based on poly(vinyl methyl ether) blends are attractive candidates for differentiation and gentle detachment of primary monocyte-derived macrophages. In summary, we observed similar functionality and viability of primary monocyte-derived macrophages cultured on thermo-responsive polymers compared to standard cell culture surfaces. While this first generation of custom-made thermo-responsive polymers does not yet outperform standard culture approaches, our results are very promising and provide the basis for exploiting the unique advantages offered by custom-made thermo-responsive polymers to further improve macrophage culture and recovery in the future, including the covalent binding of signaling molecules and the reduction of centrifugation and washing steps. Optimizing these and other benefits of thermo-responsive polymers could greatly improve the culture of macrophages for tissue engineering applications.
TD-CI simulation of the electronic optical response of molecules in intense fields II: comparison of DFT functionals and EOM-CCSD.

PubMed

Sonk, Jason A; Schlegel, H Bernhard

2011-10-27

Time-dependent configuration interaction (TD-CI) simulations can be used to simulate molecules in intense laser fields. TD-CI calculations use the excitation energies and transition dipoles calculated in the absence of a field. The EOM-CCSD method provides a good estimate of the field-free excited states but is rather expensive. Linear-response time-dependent density functional theory (TD-DFT) is an inexpensive alternative for computing the field-free excitation energies and transition dipoles needed for TD-CI simulations. Linear-response TD-DFT calculations were carried out with standard functionals (B3LYP, BH&HLYP, HSE2PBE (HSE03), BLYP, PBE, PW91, and TPSS) and long-range corrected functionals (LC-ωPBE, ωB97XD, CAM-B3LYP, LC-BLYP, LC-PBE, LC-PW91, and LC-TPSS). These calculations used the 6-31G(d,p) basis set augmented with three sets of diffuse sp functions on each heavy atom. Butadiene was employed as a test case, and 500 excited states were calculated with each functional. Standard functionals yield average excitation energies that are significantly lower than the EOM-CC, while long-range corrected functionals tend to produce average excitation energies slightly higher. Long-range corrected functionals also yield transition dipoles that are somewhat larger than EOM-CC on average. The TD-CI simulations were carried out with a three-cycle Gaussian pulse (ω = 0.06 au, 760 nm) with intensities up to 1.26 × 10(14) W cm(-2) directed along the vector connecting the end carbons. The nonlinear response as indicated by the residual populations of the excited states after the pulse is far too large with standard functionals, primarily because the excitation energies are too low. The LC-ωPBE, LC-PBE, LC-PW91, and LC-TPSS long-range corrected functionals produce responses comparable to EOM-CC.
Characterization of long-range functional connectivity in epileptic networks by neuronal spike-triggered local field potentials

NASA Astrophysics Data System (ADS)

Lopour, Beth A.; Staba, Richard J.; Stern, John M.; Fried, Itzhak; Ringach, Dario L.

2016-04-01

Objective. Quantifying the relationship between microelectrode-recorded multi-unit activity (MUA) and local field potentials (LFPs) in distinct brain regions can provide detailed information on the extent of functional connectivity in spatially widespread networks. These methods are common in studies of cognition using non-human animal models, but are rare in humans. Here we applied a neuronal spike-triggered impulse response to electrophysiological recordings from the human epileptic brain for the first time, and we evaluate functional connectivity in relation to brain areas supporting the generation of seizures. Approach. Broadband interictal electrophysiological data were recorded from microwires adapted to clinical depth electrodes that were implanted bilaterally using stereotactic techniques in six presurgical patients with medically refractory epilepsy. MUA and LFPs were isolated in each microwire, and we calculated the impulse response between the MUA on one microwire and the LFPs on a second microwire for all possible MUA/LFP pairs. Results were compared to clinical seizure localization, including sites of seizure onset and interictal epileptiform discharges. Main results. We detected significant interictal long-range functional connections in each subject, in some cases across hemispheres. Results were consistent between two independent datasets, and the timing and location of significant impulse responses reflected anatomical connectivity. However, within individual subjects, the spatial distribution of impulse responses was unique. In two subjects with clear seizure localization and successful surgery, the epileptogenic zone was associated with significant impulse responses. Significance. The results suggest that the spike-triggered impulse response can provide valuable information about the neuronal networks that contribute to seizures using only interictal data. This technique will enable testing of specific hypotheses regarding functional connectivity in epilepsy and the relationship between functional properties and imaging findings. Beyond epilepsy, we expect that the impulse response could be more broadly applied as a measure of long-range functional connectivity in studies of cognition.

Characterization of long-range functional connectivity in epileptic networks by neuronal spike-triggered local field potentials

PubMed Central

Lopour, Beth A; Staba, Richard J; Stern, John M; Fried, Itzhak; Ringach, Dario L

2017-01-01

Objective Quantifying the relationship between microelectrode-recorded multi-unit activity (MUA) and local field potentials (LFPs) in distinct brain regions can provide detailed information on the extent of functional connectivity in spatially widespread networks. These methods are common in studies of cognition using non-human animal models, but are rare in humans. Here we applied a neuronal spike-triggered impulse response to electrophysiological recordings from the human epileptic brain for the first time, and we evaluate functional connectivity in relation to brain areas supporting the generation of seizures. Approach Broadband interictal electrophysiological data were recorded from microwires adapted to clinical depth electrodes that were implanted bilaterally using stereotactic techniques in six presurgical patients with medically refractory epilepsy. MUA and LFPs were isolated in each microwire, and we calculated the impulse response between the MUA on one microwire and the LFPs on a second microwire for all possible MUA/LFP pairs. Results were compared to clinical seizure localization, including sites of seizure onset and interictal epileptiform discharges. Main results We detected significant interictal long-range functional connections in each subject, in some cases across hemispheres. Results were consistent between two independent datasets, and the timing and location of significant impulse responses reflected anatomical connectivity. However, within individual subjects, the spatial distribution of impulse responses was unique. In two subjects with clear seizure localization and successful surgery, the epileptogenic zone was associated with significant impulse responses. Significance The results suggest that the spike-triggered impulse response can provide valuable information about the neuronal networks that contribute to seizures using only interictal data. This technique will enable testing of specific hypotheses regarding functional connectivity in epilepsy and the relationship between functional properties and imaging findings. Beyond epilepsy, we expect that the impulse response could be more broadly applied as a measure of long-range functional connectivity in studies of cognition. PMID:26975603
Bone marrow support of the heart in pressure overload is lost with aging.

PubMed

Sopko, Nikolai A; Turturice, Benjamin A; Becker, Mitchell E; Brown, Chase R; Dong, Feng; Popović, Zoran B; Penn, Marc S

2010-12-21

Exogenous stem cell delivery is under investigation to prevent and treat cardiac dysfunction. It is less studied as to the extent endogenous bone marrow derived stem cells contribute to cardiac homeostais in response to stress and the affects of aging on this stress response. To determine the role of bone marrow (BM) derived stem cells on cardiac homeostasis in response to pressure overload (PO) and how this response is altered by aging. Young (8 weeks) and old (>40 weeks) C57/b6 mice underwent homo- and heterochronic BM transplantation prior to transverse aortic constriction (TAC). We found that older BM is associated with decreased cardiac function following TAC. This decreased function is associated with decrease in BM cell engraftment, increased myocyte apoptosis, decreased myocyte hypertrophy, increased myocardial fibrosis and decreased cardiac function. Additionally, there is a decrease in activation of resident cells within the heart in response to PO in old mice. Interestingly, these effects are not due to alterations in vascular density or inflammation in response to PO or differences in ex vivo stem cell migration between young and old mice. BM derived stem cells are activated in response to cardiac PO, and the recruitment of BM derived cells are involved in cardiac myocyte hypertrophy and maintenance of function in response to PO which is lost with aging.
Conceptualization of the Sexual Response Models in Men: Are there Differences Between Sexually Functional and Dysfunctional Men?

PubMed

Connaughton, Catherine; McCabe, Marita; Karantzas, Gery

2016-03-01

Research to validate models of sexual response empirically in men with and without sexual dysfunction (MSD), as currently defined, is limited. To explore the extent to which the traditional linear or the Basson circular model best represents male sexual response for men with MSD and sexually functional men. In total, 573 men completed an online questionnaire to assess sexual function and aspects of the models of sexual response. In total, 42.2% of men (242) were sexually functional, and 57.8% (331) had at least one MSD. Models were built and tested using bootstrapping and structural equation modeling. Fit of models for men with and without MSD. The linear model and the initial circular model were a poor fit for men with and without MSD. A modified version of the circular model demonstrated adequate fit for the two groups and showed important interactions between psychological factors and sexual response for men with and without MSD. Male sexual response was not represented by the linear model for men with or without MSD, excluding possible healthy responsive desire. The circular model provided a better fit for the two groups of men but demonstrated that the relations between psychological factors and phases of sexual response were different for men with and without MSD as currently defined. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.
Dual Roles for Ikaros in Regulation of Macrophage Chromatin State and Inflammatory Gene Expression.

PubMed

Oh, Kyu-Seon; Gottschalk, Rachel A; Lounsbury, Nicolas W; Sun, Jing; Dorrington, Michael G; Baek, Songjoon; Sun, Guangping; Wang, Ze; Krauss, Kathleen S; Milner, Joshua D; Dutta, Bhaskar; Hager, Gordon L; Sung, Myong-Hee; Fraser, Iain D C

2018-06-13

Macrophage activation by bacterial LPS leads to induction of a complex inflammatory gene program dependent on numerous transcription factor families. The transcription factor Ikaros has been shown to play a critical role in lymphoid cell development and differentiation; however, its function in myeloid cells and innate immune responses is less appreciated. Using comprehensive genomic analysis of Ikaros-dependent transcription, DNA binding, and chromatin accessibility, we describe unexpected dual repressor and activator functions for Ikaros in the LPS response of murine macrophages. Consistent with the described function of Ikaros as transcriptional repressor, Ikzf1 -/- macrophages showed enhanced induction for select responses. In contrast, we observed a dramatic defect in expression of many delayed LPS response genes, and chromatin immunoprecipitation sequencing analyses support a key role for Ikaros in sustained NF-κB chromatin binding. Decreased Ikaros expression in Ikzf1 +/- mice and human cells dampens these Ikaros-enhanced inflammatory responses, highlighting the importance of quantitative control of Ikaros protein level for its activator function. In the absence of Ikaros, a constitutively open chromatin state was coincident with dysregulation of LPS-induced chromatin remodeling, gene expression, and cytokine responses. Together, our data suggest a central role for Ikaros in coordinating the complex macrophage transcriptional program in response to pathogen challenge.
Response variance in functional maps: neural darwinism revisited.

PubMed

Takahashi, Hirokazu; Yokota, Ryo; Kanzaki, Ryohei

2013-01-01

The mechanisms by which functional maps and map plasticity contribute to cortical computation remain controversial. Recent studies have revisited the theory of neural Darwinism to interpret the learning-induced map plasticity and neuronal heterogeneity observed in the cortex. Here, we hypothesize that the Darwinian principle provides a substrate to explain the relationship between neuron heterogeneity and cortical functional maps. We demonstrate in the rat auditory cortex that the degree of response variance is closely correlated with the size of its representational area. Further, we show that the response variance within a given population is altered through training. These results suggest that larger representational areas may help to accommodate heterogeneous populations of neurons. Thus, functional maps and map plasticity are likely to play essential roles in Darwinian computation, serving as effective, but not absolutely necessary, structures to generate diverse response properties within a neural population.
Response Variance in Functional Maps: Neural Darwinism Revisited

PubMed Central

Takahashi, Hirokazu; Yokota, Ryo; Kanzaki, Ryohei

2013-01-01

The mechanisms by which functional maps and map plasticity contribute to cortical computation remain controversial. Recent studies have revisited the theory of neural Darwinism to interpret the learning-induced map plasticity and neuronal heterogeneity observed in the cortex. Here, we hypothesize that the Darwinian principle provides a substrate to explain the relationship between neuron heterogeneity and cortical functional maps. We demonstrate in the rat auditory cortex that the degree of response variance is closely correlated with the size of its representational area. Further, we show that the response variance within a given population is altered through training. These results suggest that larger representational areas may help to accommodate heterogeneous populations of neurons. Thus, functional maps and map plasticity are likely to play essential roles in Darwinian computation, serving as effective, but not absolutely necessary, structures to generate diverse response properties within a neural population. PMID:23874733
Suppression of Proinflammatory Cytokines in Functionalized Fullerene-Exposed Dermal Keratinocytes

DOE PAGES

Gao, Jun; Wang, Hsing-Lin; Iyer, Rashi

2010-01-01

Initial experiments using differentially functionalized fullerenes, CD-, hexa-, and tris-, suggested a properties dependent effect on cytotoxic and proliferative responses in human skin keratinocytes. In the present study we investigated the cytokine secretion profile of dermal epithelial cells exposed to functionalized fullerenes. Keratinocyte-derived cytokines affect homing and trafficking of normal and malignant epidermal immune as well as nonimmune cells in vivo. These cytokines are critical for regulating activation, proliferation, and differentiation of epidermal cells. Our results indicate that tris- (size range <100 nm) significantly reduces inflammatory cytokine release in a dose- and time-dependent manner. In contrast CD- demonstrated a relatively pro-inflammatorymore » cytokine response, while hexa- did not significantly perturb cytokine responses. Physical and chemical characterizations of these engineered nanomaterials suggest that the disparate biological responses observed may potentially be a function of the aggregation properties of these fullerenes.« less
Mitochondrial and Chloroplast Stress Responses Are Modulated in Distinct Touch and Chemical Inhibition Phases1[OPEN

PubMed Central

Ivanova, Aneta; Millar, A. Harvey; Whelan, James

2016-01-01

Previous studies have identified a range of transcription factors that modulate retrograde regulation of mitochondrial and chloroplast functions in Arabidopsis (Arabidopsis thaliana). However, the relative importance of these regulators and whether they act downstream of separate or overlapping signaling cascades is still unclear. Here, we demonstrate that multiple stress-related signaling pathways, with distinct kinetic signatures, converge on overlapping gene sets involved in energy organelle function. The transcription factor ANAC017 is almost solely responsible for transcript induction of marker genes around 3 to 6 h after chemical inhibition of organelle function and is a key regulator of mitochondrial and specific types of chloroplast retrograde signaling. However, an independent and highly transient gene expression phase, initiated within 10 to 30 min after treatment, also targets energy organelle functions, and is related to touch and wounding responses. Metabolite analysis demonstrates that this early response is concurrent with rapid changes in tricarboxylic acid cycle intermediates and large changes in transcript abundance of genes encoding mitochondrial dicarboxylate carrier proteins. It was further demonstrated that transcription factors AtWRKY15 and AtWRKY40 have repressive regulatory roles in this touch-responsive gene expression. Together, our results show that several regulatory systems can independently affect energy organelle function in response to stress, providing different means to exert operational control. PMID:27208304
Ethylene Response Factor TERF1, Regulated by ETHYLENE-INSENSITIVE3-like Factors, Functions in Reactive Oxygen Species (ROS) Scavenging in Tobacco (Nicotiana tabacum L.).

PubMed

Zhang, Hongbo; Li, Ang; Zhang, Zhijin; Huang, Zejun; Lu, Pingli; Zhang, Dingyu; Liu, Xinmin; Zhang, Zhong-Feng; Huang, Rongfeng

2016-07-20

The phytohormone ethylene plays a crucial role in the production and accumulation of reactive oxygen species (ROS) in plants under stress conditions. Ethylene response factors (ERFs) are important ethylene-signaling regulators functioning in plant defense responses against biotic and abiotic stresses. However, the roles of ERFs during plant adapting to ROS stress have not yet been well documented. Our studies previously reported that a tomato ERF transcription factor TERF1 functions in the regulation of plant ethylene responses and stress tolerance. Here, we report our findings regarding the roles of TERF1 in ROS scavenging. In this study, we revealed that the transcription of TERF1 is regulated by upstream EIN3-like (EIN3, ethylene-insensitive 3) regulators LeEIL3 and LeEIL4 in tomato (Solanum lycopersicum), and is also inducible by exogenous applied ROS-generating reagents. Ectopic expression of TERF1 in tobacco promoted the expression of genes involved in oxidative stress responses, including carbonic anhydrase functioning in hypersensitive defense, catalase and glutathione peroxidase catalyzing oxidative reactions, and GDP-D-mannose pyrophosphorylase functioning in ascorbic acid biosynthesis, reduced the ROS content induced by ethylene treatment, and enhanced stress tolerance of tobacco seedlings to hydrogen peroxide (H2O2). Cumulatively, these findings suggest that TERF1 is an ethylene inducible factor regulating ROS scavenging during stress responses.
Stimuli-Responsive DNA-Based Hydrogels: From Basic Principles to Applications.

PubMed

Kahn, Jason S; Hu, Yuwei; Willner, Itamar

2017-04-18

The base sequence of nucleic acids encodes structural and functional information into the DNA biopolymer. External stimuli such as metal ions, pH, light, or added nucleic acid fuel strands provide triggers to reversibly switch nucleic acid structures such as metal-ion-bridged duplexes, i-motifs, triplex nucleic acids, G-quadruplexes, or programmed double-stranded hybrids of oligonucleotides (DNA). The signal-triggered oligonucleotide structures have been broadly applied to develop switchable DNA nanostructures and DNA machines, and these stimuli-responsive assemblies provide functional scaffolds for the rapidly developing area of DNA nanotechnology. Stimuli-responsive hydrogels undergoing signal-triggered hydrogel-to-solution transitions or signal-controlled stiffness changes attract substantial interest as functional matrices for controlled drug delivery, materials exhibiting switchable mechanical properties, acting as valves or actuators, and "smart" materials for sensing and information processing. The integration of stimuli-responsive oligonucleotides with hydrogel-forming polymers provides versatile means to exploit the functional information encoded in the nucleic acid sequences to yield stimuli-responsive hydrogels exhibiting switchable physical, structural, and chemical properties. Stimuli-responsive DNA-based nucleic acid structures are integrated in acrylamide polymer chains and reversible, switchable hydrogel-to-solution transitions of the systems are demonstrated by applying external triggers, such as metal ions, pH-responsive strands, G-quadruplex, and appropriate counter triggers that bridge and dissociate the polymer chains. By combining stimuli-responsive nucleic acid bridges with thermosensitive poly(N-isopropylacrylamide) (pNIPAM) chains, systems undergoing reversible solution ↔ hydrogel ↔ solid transitions are demonstrated. Specifically, by bridging acrylamide polymer chains by two nucleic acid functionalities, where one type of bridging unit provides a stimuli-responsive element and the second unit acts as internal "bridging memory", shape-memory hydrogels undergoing reversible and switchable transitions between shaped hydrogels and shapeless quasi-liquid states are demonstrated. By using stimuli-responsive hydrogel cross-linking units that can assemble the bridging units by two different input signals, the orthogonally-triggered functions of the shape-memory were shown. Furthermore, a versatile approach to assemble stimuli-responsive DNA-based acrylamide hydrogel films on surfaces is presented. The method involves the activation of the hybridization chain-reaction (HCR) by a surface-confined promoter strand, in the presence of acrylamide chains modified with two DNA hairpin structures and appropriate stimuli-responsive tethers. The resulting hydrogel-modified surfaces revealed switchable stiffness properties and signal-triggered catalytic functions. By applying the method to assemble the hydrogel microparticles, substrate-loaded, stimuli-responsive microcapsules are prepared. The signal-triggered DNA-based hydrogel microcapsules are applied as drug carriers for controlled release. The different potential applications and future perspectives of stimuli responsive hydrogels are discussed. Specifically, the use of these smart materials and assemblies as carriers for controlled drug release and as shape-memory matrices for information storage and inscription and the use of surface-confined stimuli-responsive hydrogels, exhibiting switchable stiffness properties, for catalysis and controlled growth of cells are discussed.
AESOP- INTERACTIVE DESIGN OF LINEAR QUADRATIC REGULATORS AND KALMAN FILTERS

NASA Technical Reports Server (NTRS)

Lehtinen, B.

1994-01-01

AESOP was developed to solve a number of problems associated with the design of controls and state estimators for linear time-invariant systems. The systems considered are modeled in state-variable form by a set of linear differential and algebraic equations with constant coefficients. Two key problems solved by AESOP are the linear quadratic regulator (LQR) design problem and the steady-state Kalman filter design problem. AESOP is designed to be used in an interactive manner. The user can solve design problems and analyze the solutions in a single interactive session. Both numerical and graphical information are available to the user during the session. The AESOP program is structured around a list of predefined functions. Each function performs a single computation associated with control, estimation, or system response determination. AESOP contains over sixty functions and permits the easy inclusion of user defined functions. The user accesses these functions either by inputting a list of desired functions in the order they are to be performed, or by specifying a single function to be performed. The latter case is used when the choice of function and function order depends on the results of previous functions. The available AESOP functions are divided into several general areas including: 1) program control, 2) matrix input and revision, 3) matrix formation, 4) open-loop system analysis, 5) frequency response, 6) transient response, 7) transient function zeros, 8) LQR and Kalman filter design, 9) eigenvalues and eigenvectors, 10) covariances, and 11) user-defined functions. The most important functions are those that design linear quadratic regulators and Kalman filters. The user interacts with AESOP when using these functions by inputting design weighting parameters and by viewing displays of designed system response. Support functions obtain system transient and frequency responses, transfer functions, and covariance matrices. AESOP can also provide the user with open-loop system information including stability, controllability, and observability. The AESOP program is written in FORTRAN IV for interactive execution and has been implemented on an IBM 3033 computer using TSS 370. As currently configured, AESOP has a central memory requirement of approximately 2 Megs of 8 bit bytes. Memory requirements can be reduced by redimensioning arrays in the AESOP program. Graphical output requires adaptation of the AESOP plot routines to whatever device is available. The AESOP program was developed in 1984.
Emotional Responses to Odors in Children with High-Functioning Autism: Autonomic Arousal, Facial Behavior and Self-Report

ERIC Educational Resources Information Center

Legisa, Jasna; Messinger, Daniel S.; Kermol, Enzo; Marlier, Luc

2013-01-01

Although emotional functioning is impaired in children with autism, it is unclear if this impairment is due to difficulties with facial expression, autonomic responsiveness, or the verbal description of emotional states. To shed light on this issue, we examined responses to pleasant and unpleasant odors in eight children (8-14 years) with…
An Examination of the Literature on the Function and Responsibilities of Board of Directors in Not for Profit Organizations.

ERIC Educational Resources Information Center

Weis, Suzanne; Wynn, Patricia

A review of the literature on the functions and responsibilities of the board of trustees in nonprofit organizations shows the following as major areas of responsibility: (1) determinatlon of agency policy and assumption of the ongoing role of monitoring performance against established policies; (2) allocation of the organization's resources,…
Person Response Functions and the Definition of Units in the Social Sciences

ERIC Educational Resources Information Center

Engelhard, George, Jr.; Perkins, Aminah F.

2011-01-01

Humphry (this issue) has written a thought-provoking piece on the interpretation of item discrimination parameters as scale units in item response theory. One of the key features of his work is the description of an item response theory (IRT) model that he calls the logistic measurement function that combines aspects of two traditions in IRT that…
25 CFR 12.1 - Who is responsible for the Bureau of Indian Affairs law enforcement function?

Code of Federal Regulations, 2010 CFR

2010-04-01

..., the Deputy Commissioner, is responsible for Bureau of Indian Affairs-operated and contracted law... 25 Indians 1 2010-04-01 2010-04-01 false Who is responsible for the Bureau of Indian Affairs law enforcement function? 12.1 Section 12.1 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND...
Exercise, oxidants, and antioxidants change the shape of the bell-shaped hormesis curve.

PubMed

Radak, Zsolt; Ishihara, Kazunari; Tekus, Eva; Varga, Csaba; Posa, Aniko; Balogh, Laszlo; Boldogh, Istvan; Koltai, Erika

2017-08-01

It is debated whether exercise-induced ROS production is obligatory to cause adaptive response. It is also claimed that antioxidant treatment could eliminate the adaptive response, which appears to be systemic and reportedly reduces the incidence of a wide range of diseases. Here we suggest that if the antioxidant treatment occurs before the physiological function-ROS dose-response curve reaches peak level, the antioxidants can attenuate function. On the other hand, if the antioxidant treatment takes place after the summit of the bell-shaped dose response curve, antioxidant treatment would have beneficial effects on function. We suggest that the effects of antioxidant treatment are dependent on the intensity of exercise, since the adaptive response, which is multi pathway dependent, is strongly influenced by exercise intensity. It is further suggested that levels of ROS concentration are associated with peak physiological function and can be extended by physical fitness level and this could be the basis for exercise pre-conditioning. Physical inactivity, aging or pathological disorders increase the sensitivity to oxidative stress by altering the bell-shaped dose response curve. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
KAOS/LIB-V: A library of nuclear response functions generated by KAOS-V code from ENDF/B-V and other data files

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

Farawila, Y.; Gohar, Y.; Maynard, C.

1989-04-01

KAOS/LIB-V: A library of processed nuclear responses for neutronics analyses of nuclear systems has been generated. The library was prepared using the KAOS-V code and nuclear data from ENDF/B-V. The library includes kerma (kinetic energy released in materials) factors and other nuclear response functions for all materials presently of interest in fusion and fission applications for 43 nonfissionable and 15 fissionable isotopes and elements. The nuclear response functions include gas production and tritium-breeding functions, and all important reaction cross sections. KAOS/LIB-V employs the VITAMIN-E weighting function and energy group structure of 174 neutron groups. Auxiliary nuclear data bases, e.g., themore » Japanese evaluated nuclear data library JENDL-2 were used as a source of isotopic cross sections when these data are not provided in ENDF/B-V files for a natural element. These are needed mainly to estimate average quantities such as effective Q-values for the natural element. This analysis of local energy deposition was instrumental in detecting and understanding energy balance deficiencies and other problems in the ENDF/B-V data. Pertinent information about the library and a graphical display of the main nuclear response functions for all materials in the library are given. 35 refs.« less
Influence of dexmedetomidine on cognitive function in volunteers.

PubMed

Yatabe, Tomoaki; Tamura, Takahiko; Yamashita, Koichi; Yokoyama, Masataka

2016-09-01

Some outpatient procedures are performed under sedation with dexmedetomidine, although the effect of dexmedetomidine on cognitive function remains unclear. This study investigated the effect of dexmedetomidine on cognitive function in healthy volunteers. Observation study in volunteers. University-affiliated teaching hospital. Six healthy volunteers. After infusion of a 6-μg/kg per hour loading dose of dexmedetomidine for 10 minutes, a maintenance infusion of 0.4 μg/kg per hour was administered for 4 hours. Cognitive function was evaluated before infusion (baseline) and at 2, 4, 6, and 8 hours after infusion. Cognitive function, response speed, accuracy, and consistency were measured by CogHealth. Depth of sedation was evaluated at 1-hour intervals by evaluating the Bispectral Index. Data are presented as the change from baseline. The Bispectral Index value was significantly lower from 10 minutes to 6 hours after infusion versus the pre-infusion value. Response speed was also significantly lower at 2 hours and 4 hours after infusion (92 ± 8%, P< .0001; 93 ± 6%, P< .0001), as was consistency (96 ± 7%, P= .0009; 96 ± 5%, P= .0003). Response accuracy was unaltered by the infusion. Dexmedetomidine slightly reduced response speed and consistency, but did not affect response accuracy. Cognitive function was restored to pre-administration values 2 hours after the infusion of dexmedetomidine was discontinued. Copyright © 2016 Elsevier Inc. All rights reserved.
B cell function in the immune response to helminths

PubMed Central

Harris, Nicola

2010-01-01

Similar T helper (Th)2-type immune responses are generated against different helminths parasites, but the mechanisms that initiate Th2 immunity, and the specific immune components that mediate protection against these parasites, can vary greatly. B cells are increasingly recognized as important during the Th2-type immune response to helminths, and B cell activation might be a target for effective vaccine development. Antibody production is a function of B cells during helminth infection and understanding how polyclonal and antigen-specific antibodies contribute should provide important insights into how protective immunity develops. In addition, B cells might also contribute to the host response against helminths through antibody-independent functions including, antigen-presentation, as well as regulatory and effector activity. In this review, we examine the role of B cells during Th2-type immune response to these multicellular parasites. PMID:21159556
Predator-dependent functional response in wolves: from food limitation to surplus killing.

PubMed

Zimmermann, Barbara; Sand, Håkan; Wabakken, Petter; Liberg, Olof; Andreassen, Harry Peter

2015-01-01

The functional response of a predator describes the change in per capita kill rate to changes in prey density. This response can be influenced by predator densities, giving a predator-dependent functional response. In social carnivores which defend a territory, kill rates also depend on the individual energetic requirements of group members and their contribution to the kill rate. This study aims to provide empirical data for the functional response of wolves Canis lupus to the highly managed moose Alces alces population in Scandinavia. We explored prey and predator dependence, and how the functional response relates to the energetic requirements of wolf packs. Winter kill rates of GPS-collared wolves and densities of cervids were estimated for a total of 22 study periods in 15 wolf territories. The adult wolves were identified as the individuals responsible for providing kills to the wolf pack, while pups could be described as inept hunters. The predator-dependent, asymptotic functional response models (i.e. Hassell-Varley type II and Crowley-Martin) performed best among a set of 23 competing linear, asymptotic and sigmoid models. Small wolf packs acquired >3 times as much moose biomass as required to sustain their field metabolic rate (FMR), even at relatively low moose abundances. Large packs (6-9 wolves) acquired less biomass than required in territories with low moose abundance. We suggest the surplus killing by small packs is a result of an optimal foraging strategy to consume only the most nutritious parts of easy accessible prey while avoiding the risk of being detected by humans. Food limitation may have a stabilizing effect on pack size in wolves, as supported by the observed negative relationship between body weight of pups and pack size. © 2014 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

Trade Spaces in Crewed Spacecraft Atmosphere Revitalization System Development

NASA Technical Reports Server (NTRS)

Perry, Jay L.; Bagdigian, Robert M.; Carrasquillo, Robyn L.

2010-01-01

Developing the technological response to realizing an efficient atmosphere revitalization system for future crewed spacecraft and space habitats requires identifying and describing functional trade spaces. Mission concepts and requirements dictate the necessary functions; however, the combination and sequence of those functions possess significant flexibility. Us-ing a closed loop environmental control and life support (ECLS) system architecture as a starting basis, a functional unit operations approach is developed to identify trade spaces. Generalized technological responses to each trade space are discussed. Key performance parameters that apply to functional areas are described.
The Role of Inhibition in Age-related Off-Topic Verbosity: Not Access but Deletion and Restraint Functions

PubMed Central

Yin, Shufei; Peng, Huamao

2016-01-01

The speech of older adults is commonly described as verbose and off-topic, which is thought to influence their social communication. This study investigated the role of inhibition in age-related off-topic verbosity (OTV). Inhibition consists of three functions: access, deletion, and restraint. The access function is responsible for preventing irrelevant information from accessing the attention center (pre-mechanism of inhibition); The deletion function is responsible for deleting previously relevant but currently irrelevant information from working memory, and the restraint function is responsible for restraining strong but inappropriate responses (post-mechanisms of inhibition). A referential communication task was used to determine whether OTV was influenced by the pre-mechanism of inhibition. A self-involved event interview task was used to investigate the effect of the post-mechanisms of inhibition on OTV. Results showed that the OTV of the elderly participants was associated with an age-related decline in the post-mechanisms of inhibition, while the OTV exhibited by young adults was most likely due to deficits in the pre-mechanism function of inhibition. This research contributed to fill gaps in the existing knowledge about the potential relationship between specific functions of inhibition and age-related OTV. PMID:27199793
Brain dynamics in ASD during movie-watching show idiosyncratic functional integration and segregation.

PubMed

Bolton, Thomas A W; Jochaut, Delphine; Giraud, Anne-Lise; Van De Ville, Dimitri

2018-06-01

To refine our understanding of autism spectrum disorders (ASD), studies of the brain in dynamic, multimodal and ecological experimental settings are required. One way to achieve this is to compare the neural responses of ASD and typically developing (TD) individuals when viewing a naturalistic movie, but the temporal complexity of the stimulus hampers this task, and the presence of intrinsic functional connectivity (FC) may overshadow movie-driven fluctuations. Here, we detected inter-subject functional correlation (ISFC) transients to disentangle movie-induced functional changes from underlying resting-state activity while probing FC dynamically. When considering the number of significant ISFC excursions triggered by the movie across the brain, connections between remote functional modules were more heterogeneously engaged in the ASD population. Dynamically tracking the temporal profiles of those ISFC changes and tying them to specific movie subparts, this idiosyncrasy in ASD responses was then shown to involve functional integration and segregation mechanisms such as response inhibition, background suppression, or multisensory integration, while low-level visual processing was spared. Through the application of a new framework for the study of dynamic experimental paradigms, our results reveal a temporally localized idiosyncrasy in ASD responses, specific to short-lived episodes of long-range functional interplays. © 2018 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
The role of the mesolimbic dopamine system in the formation of blood-oxygen-level dependent responses in the medial prefrontal/anterior cingulate cortex during high-frequency stimulation of the rat perforant pathway.

PubMed

Helbing, Cornelia; Brocka, Marta; Scherf, Thomas; Lippert, Michael T; Angenstein, Frank

2016-12-01

Several human functional magnetic resonance imaging studies point to an activation of the mesolimbic dopamine system during reward, addiction and learning. We previously found activation of the mesolimbic system in response to continuous but not to discontinuous perforant pathway stimulation in an experimental model that we now used to investigate the role of dopamine release for the formation of functional magnetic resonance imaging responses. The two stimulation protocols elicited blood-oxygen-level dependent responses in the medial prefrontal/anterior cingulate cortex and nucleus accumbens. Inhibition of dopamine D 1/5 receptors abolished the formation of functional magnetic resonance imaging responses in the medial prefrontal/anterior cingulate cortex during continuous but not during discontinuous pulse stimulations, i.e. only when the mesolimbic system was activated. Direct electrical or optogenetic stimulation of the ventral tegmental area caused strong dopamine release but only electrical stimulation triggered significant blood-oxygen level-dependent responses in the medial prefrontal/anterior cingulate cortex and nucleus accumbens. These functional magnetic resonance imaging responses were not affected by the D 1/5 receptor antagonist SCH23390 but reduced by the N-methyl-D-aspartate receptor antagonist MK801. Therefore, glutamatergic ventral tegmental area neurons are already sufficient to trigger blood-oxygen-level dependent responses in the medial prefrontal/anterior cingulate cortex and nucleus accumbens. Although dopamine release alone does not affect blood-oxygen-level dependent responses it can act as a switch, permitting the formation of blood-oxygen-level dependent responses. © The Author(s) 2015.
Child pain catastrophizing mediates the relation between parent responses to pain and disability in youth with functional abdominal pain.

PubMed

Cunningham, Natoshia R; Lynch-Jordan, Anne; Barnett, Kimberly; Peugh, James; Sil, Soumitri; Goldschneider, Kenneth; Kashikar-Zuck, Susmita

2014-12-01

Functional abdominal pain (FAP) in youth is associated with substantial impairment in functioning, and prior research has shown that overprotective parent responses can heighten impairment. Little is known about how a range of parental behaviors (overprotection, minimizing, and/or encouragement) in response to their child's pain interact with child coping characteristics (eg, catastrophizing) to influence functioning in youth with FAP. In this study, it was hypothesized that the relation between parenting factors and child disability would be mediated by children's levels of maladaptive coping (ie, pain catastrophizing). Seventy-five patients with FAP presenting to a pediatric pain clinic and their caregivers participated in the study. Youth completed measures of pain intensity (Numeric Rating Scale), pain catastrophizing (Pain Catastrophizing Scale), and disability (Functional Disability Inventory). Caregivers completed measures of parent pain catastrophizing (Pain Catastrophizing Scale), and parent responses to child pain behaviors (Adult Responses to Child Symptoms: Protection, Minimizing, and Encouragement/Monitoring subscales). Increased functional disability was significantly related to higher child pain intensity, increased child and parent pain catastrophizing, and higher levels of encouragement/monitoring and protection. Parent minimization was not related to disability. Child pain catastrophizing fully mediated the relation between parent encouragement/monitoring and disability and partially mediated the relation between parent protectiveness and disability. The impact of parenting behaviors in response to FAP on child disability is determined, in part, by the child's coping style. Findings highlight a more nuanced understanding of the parent-child interaction in determining pain-related disability levels, which should be taken into consideration in assessing and treating youth with FAP.
Study of cumulative fatigue damage detection for used parts with nonlinear output frequency response functions based on NARMAX modelling

NASA Astrophysics Data System (ADS)

Huang, Honglan; Mao, Hanying; Mao, Hanling; Zheng, Weixue; Huang, Zhenfeng; Li, Xinxin; Wang, Xianghong

2017-12-01

Cumulative fatigue damage detection for used parts plays a key role in the process of remanufacturing engineering and is related to the service safety of the remanufactured parts. In light of the nonlinear properties of used parts caused by cumulative fatigue damage, the based nonlinear output frequency response functions detection approach offers a breakthrough to solve this key problem. First, a modified PSO-adaptive lasso algorithm is introduced to improve the accuracy of the NARMAX model under impulse hammer excitation, and then, an effective new algorithm is derived to estimate the nonlinear output frequency response functions under rectangular pulse excitation, and a based nonlinear output frequency response functions index is introduced to detect the cumulative fatigue damage in used parts. Then, a novel damage detection approach that integrates the NARMAX model and the rectangular pulse is proposed for nonlinear output frequency response functions identification and cumulative fatigue damage detection of used parts. Finally, experimental studies of fatigued plate specimens and used connecting rod parts are conducted to verify the validity of the novel approach. The obtained results reveal that the new approach can detect cumulative fatigue damages of used parts effectively and efficiently and that the various values of the based nonlinear output frequency response functions index can be used to detect the different fatigue damages or working time. Since the proposed new approach can extract nonlinear properties of systems by only a single excitation of the inspected system, it shows great promise for use in remanufacturing engineering applications.
Individual variation in functional response parameters is explained by body size but not by behavioural types in a poeciliid fish.

PubMed

Schröder, Arne; Kalinkat, Gregor; Arlinghaus, Robert

2016-12-01

Functional responses are per-capita feeding rate models whose parameters often scale with individual body size but the parameters may also be further influenced by behavioural traits consistently differing among individuals, i.e. behavioural types or animal personalities. Behavioural types may intrinsically lead to lower feeding rates when consistently shy, inactive and easily stressed individuals cannot identify or respond to risk-free environments or need less food due to lower metabolic rates linked to behaviour. To test how much variation in functional response parameters is explained by body size and how much by behavioural types, we estimated attack rate and handling time individually for differently sized female least killifish (Heterandria formosa) and repeatedly measured behavioural traits for each individual. We found that individual fish varied substantially in their attack rate and in their handling time. Behavioural traits were stable over time and varied consistently among individuals along two distinct personality axes. The individual variation in functional responses was explained solely by body size, and contrary to our expectations, not additionally by the existing behavioural types in exploration activity and coping style. While behavioural trait-dependent functional responses may offer a route to the understanding of the food web level consequences of behavioural types, our study is so far only the second one on this topic. Importantly, our results indicate in contrast to that previous study that behavioural types do not per se affect individual functional responses assessed in the absence of external biotic stressors.
Right ventricular pressure response to exercise in adults with isolated ventricular septal defect closed in early childhood.

PubMed

Moller, Thomas; Lindberg, Harald; Lund, May Brit; Holmstrom, Henrik; Dohlen, Gaute; Thaulow, Erik

2018-06-01

We previously demonstrated an abnormally high right ventricular systolic pressure response to exercise in 50% of adolescents operated on for isolated ventricular septal defect. The present study investigated the prevalence of abnormal right ventricular systolic pressure response in 20 adult (age 30-45 years) patients who underwent surgery for early ventricular septal defect closure and its association with impaired ventricular function, pulmonary function, or exercise capacity. The patients underwent cardiopulmonary tests, including exercise stress echocardiography. Five of 19 patients (26%) presented an abnormal right ventricular systolic pressure response to exercise ⩾ 52 mmHg. Right ventricular systolic function was mixed, with normal tricuspid annular plane systolic excursion and fractional area change, but abnormal tricuspid annular systolic motion velocity (median 6.7 cm/second) and isovolumetric acceleration (median 0.8 m/second2). Left ventricular systolic and diastolic function was normal at rest as measured by the peak systolic velocity of the lateral wall and isovolumic acceleration, early diastolic velocity, and ratio of early diastolic flow to tissue velocity, except for ejection fraction (median 53%). The myocardial performance index was abnormal for both the left and right ventricle. Peak oxygen uptake was normal (mean z score -0.4, 95% CI -2.8-0.3). There was no association between an abnormal right ventricular systolic pressure response during exercise and right or left ventricular function, pulmonary function, or exercise capacity. Abnormal right ventricular pressure response is not more frequent in adult patients compared with adolescents. This does not support the theory of progressive pulmonary vascular disease following closure of left-to-right shunts.
Application of response surface techniques to helicopter rotor blade optimization procedure

NASA Technical Reports Server (NTRS)

Henderson, Joseph Lynn; Walsh, Joanne L.; Young, Katherine C.

1995-01-01

In multidisciplinary optimization problems, response surface techniques can be used to replace the complex analyses that define the objective function and/or constraints with simple functions, typically polynomials. In this work a response surface is applied to the design optimization of a helicopter rotor blade. In previous work, this problem has been formulated with a multilevel approach. Here, the response surface takes advantage of this decomposition and is used to replace the lower level, a structural optimization of the blade. Problems that were encountered and important considerations in applying the response surface are discussed. Preliminary results are also presented that illustrate the benefits of using the response surface.
Plant functional group responses to fire frequency and tree canopy cover gradients in oak savannas and woodlands.

Treesearch

D.W. Peterson; P.B. Reich; K.J. Wrage

2007-01-01

We measured plant functional group cover and tree canopy cover on permanent plots within a long-term prescribed fire frequency experiment and used hierarchical linear modeling to assess plant functional group responses to fire frequency and tree canopy cover. Understory woody plant cover was highest in unburned woodlands and was negatively correlated with fire...
A Functional Analysis of Non-Vocal Verbal Behavior of a Young Child with Autism

ERIC Educational Resources Information Center

Normand, M. P.; Severtson, E. S.; Beavers, G. A.

2008-01-01

The functions of an American Sign Language response were experimentally evaluated with a young boy diagnosed with autism. A functional analysis procedure based on that reported by Lerman et al. (2005) was used to evaluate whether the target sign response would occur under mand, tact, mimetic, or control conditions. The target sign was observed…
Association Between Brain Activation and Functional Connectivity.

PubMed

Tomasi, Dardo; Volkow, Nora D

2018-04-13

The origin of the "resting-state" brain activity recorded with functional magnetic resonance imaging (fMRI) is still uncertain. Here we provide evidence for the neurovascular origins of the amplitude of the low-frequency fluctuations (ALFF) and the local functional connectivity density (lFCD) by comparing them with task-induced blood-oxygen level dependent (BOLD) responses, which are considered a proxy for neuronal activation. Using fMRI data for 2 different tasks (Relational and Social) collected by the Human Connectome Project in 426 healthy adults, we show that ALFF and lFCD have linear associations with the BOLD response. This association was significantly attenuated by a novel task signal regression (TSR) procedure, indicating that task performance enhances lFCD and ALFF in activated regions. We also show that lFCD predicts BOLD activation patterns, as was recently shown for other functional connectivity metrics, which corroborates that resting functional connectivity architecture impacts brain activation responses. Thus, our findings indicate a common source for BOLD responses, ALFF and lFCD, which is consistent with the neurovascular origin of local hemodynamic synchrony presumably reflecting coordinated fluctuations in neuronal activity. This study also supports the development of task-evoked functional connectivity density mapping.
On the Relationship Between Transfer Function-derived Response Times and Hydrograph Analysis Timing Parameters: Are there Similarities?

NASA Astrophysics Data System (ADS)

Bansah, S.; Ali, G.; Haque, M. A.; Tang, V.

2017-12-01

The proportion of precipitation that becomes streamflow is a function of internal catchment characteristics - which include geology, landscape characteristics and vegetation - and influence overall storage dynamics. The timing and quantity of water discharged by a catchment are indeed embedded in event hydrographs. Event hydrograph timing parameters, such as the response lag and time of concentration, are important descriptors of how long it takes the catchment to respond to input precipitation and how long it takes the latter to filter through the catchment. However, the extent to which hydrograph timing parameters relate to average response times derived from fitting transfer functions to annual hydrographs is unknown. In this study, we used a gamma transfer function to determine catchment average response times as well as event-specific hydrograph parameters across a network of eight nested watersheds ranging from 0.19 km2 to 74.6 km2 prairie catchments located in south central Manitoba (Canada). Various statistical analyses were then performed to correlate average response times - estimated using the parameters of the fitted gamma transfer function - to event-specific hydrograph parameters. Preliminary results show significant interannual variations in response times and hydrograph timing parameters: the former were in the order of a few hours to days, while the latter ranged from a few days to weeks. Some statistically significant relationships were detected between response times and event-specific hydrograph parameters. Future analyses will involve the comparison of statistical distributions of event-specific hydrograph parameters with that of runoff response times and baseflow transit times in order to quantity catchment storage dynamics across a range of temporal scales.
Intrinsic functional defects of type 2 innate lymphoid cells impair innate allergic inflammation in promyelocytic leukemia zinc finger (PLZF)-deficient mice.

PubMed

Verhoef, Philip A; Constantinides, Michael G; McDonald, Benjamin D; Urban, Joseph F; Sperling, Anne I; Bendelac, Albert

2016-02-01

The transcription factor promyelocytic leukemia zinc finger (PLZF) is transiently expressed during development of type 2 innate lymphoid cells (ILC2s) but is not present at the mature stage. We hypothesized that PLZF-deficient ILC2s have functional defects in the innate allergic response and represent a tool for studying innate immunity in a mouse with a functional adaptive immune response. We determined the consequences of PLZF deficiency on ILC2 function in response to innate and adaptive immune stimuli by using PLZF(-/-) mice and mixed wild-type:PLZF(-/-) bone marrow chimeras. PLZF(-/-) mice, wild-type littermates, or mixed bone marrow chimeras were treated with the protease allergen papain or the cytokines IL-25 and IL-33 or infected with the helminth Nippostrongylus brasiliensis to induce innate type 2 allergic responses. Mice were sensitized with intraperitoneal ovalbumin-alum, followed by intranasal challenge with ovalbumin alone, to induce adaptive TH2 responses. Lungs were analyzed for immune cell subsets, and alveolar lavage fluid was analyzed for ILC2-derived cytokines. In addition, ILC2s were stimulated ex vivo for their capacity to release type 2 cytokines. PLZF-deficient lung ILC2s exhibit a cell-intrinsic defect in the secretion of IL-5 and IL-13 in response to innate stimuli, resulting in defective recruitment of eosinophils and goblet cell hyperplasia. In contrast, the adaptive allergic inflammatory response to ovalbumin and alum was unimpaired. PLZF expression at the innate lymphoid cell precursor stage has a long-range effect on the functional properties of mature ILC2s and highlights the importance of these cells for innate allergic responses in otherwise immunocompetent mice. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. All rights reserved.
End-to-end test of the electron-proton spectrometer

NASA Technical Reports Server (NTRS)

Cash, B. L.

1972-01-01

A series of end-to-end tests were performed to demonstrate the proper functioning of the complete Electron-Proton Spectrometer (EPS). The purpose of the tests was to provide experimental verification of the design and to provide a complete functional performance check of the instrument from the excitation of the sensors to and including the data processor and equipment test set. Each of the channels of the EPS was exposed to a calibrated beam of energetic particles, and counts were accumulated for a predetermined period of time for each of several energies. The counts were related to the known flux of particles to give a monodirectional response function for each channel. The measured response function of the test unit was compared to the response function determined for the calibration sensors from the data taken from the calibration program.
[Ventricular tachycardia in a patient with rate-responsive cardiac pacemaker].

PubMed

Himbert, C; Lascault, G; Tonet, J; Coutte, R; Busquet, P; Frank, R; Grosgogeat, Y

1992-11-01

The authors report a case of syncopal ventricular tachycardia in a patient with a respiratory-dependent rate responsive pacemaker, followed-up for valvular heart disease with severe left ventricular dysfunction and sustained atrial and ventricular arrhythmias. The introduction of low dose betablocker therapy with reinforcement of the treatment of cardiac failure controlled the ventricular arrhythmia, after suppression of the data responsive function had been shown to be ineffective. The authors discuss the role of the rate responsive function in the triggering of the ventricular tachycardias.
Nanoparticle-based B-cell targeting vaccines: Tailoring of humoral immune responses by functionalization with different TLR-ligands.

PubMed

Zilker, Claudia; Kozlova, Diana; Sokolova, Viktoriya; Yan, Huimin; Epple, Matthias; Überla, Klaus; Temchura, Vladimir

2017-01-01

Induction of an appropriate type of humoral immune response during vaccination is essential for protection against viral and bacterial infections. We recently observed that biodegradable calcium phosphate (CaP) nanoparticles coated with proteins efficiently targeted and activated naïve antigen-specific B-cells in vitro. We now compared different administration routes for CaP-nanoparticles and demonstrated that intramuscular immunization with such CaP-nanoparticles induced stronger immune responses than immunization with monovalent antigen. Additional functionalization of the CaP-nanoparticles with TRL-ligands allowed modulating the IgG subtype response and the level of mucosal IgA antibodies. CpG-containing CaP-nanoparticles were as immunogenic as a virus-like particle vaccine. Functionalization of CaP-nanoparticles with T-helper cell epitopes or CpG also allowed overcoming lack of T-cell help. Thus, our results indicate that CaP-nanoparticle-based B-cell targeting vaccines functionalized with TLR-ligands can serve as a versatile platform for efficient induction and modulation of humoral immune responses in vivo. Copyright © 2016 Elsevier Inc. All rights reserved.
Plant hydraulic diversity buffers forest ecosystem responses to drought

NASA Astrophysics Data System (ADS)

Anderegg, W.; Konings, A. G.; Trugman, A. T.; Pacala, S. W.; Yu, K.; Sulman, B. N.; Sperry, J.; Bowling, D. R.

2017-12-01

Drought impacts carbon, water, and energy cycles in forests and may pose a fundamental threat to forests in future climates. Plant hydraulic transport of water is central to tree drought responses, including curtailing of water loss and the risk of mortality during drought. The effect of biodiversity on ecosystem function has typically been examined in grasslands, yet the diversity of plant hydraulic strategies may influence forests' response to drought. In a combined analysis of eddy covariance measurements, remote-sensing data of plant water content variation, model simulations, and plant hydraulic trait data, we test the degree to which plant water stress schemes influence the carbon cycle and how hydraulic diversity within and across ecosystems affects large-scale drought responses. We find that current plant functional types are not well-suited to capture hydraulic variation and that higher hydraulic diversity buffers ecosystem variation during drought. Our results demonstrate that tree functional diversity, particularly hydraulic diversity, may be critical to simulate in plant functional types in current land surface model projections of future vegetation's response to climate extremes.
A Potential Function Derivation of a Constitutive Equation for Inelastic Material Response

NASA Technical Reports Server (NTRS)

Stouffer, D. C.; Elfoutouh, N. A.

1983-01-01

Physical and thermodynamic concepts are used to develop a potential function for application to high temperature polycrystalline material response. Inherent in the formulation is a differential relationship between the potential function and constitutive equation in terms of the state variables. Integration of the differential relationship produces a state variable evolution equation that requires specification of the initial value of the state variable and its time derivative. It is shown that the initial loading rate, which is directly related to the initial hardening rate, can significantly influence subsequent material response. This effect is consistent with observed material behavior on the macroscopic and microscopic levels, and may explain the wide scatter in response often found in creep testing.
Sensitive subgroups and normal variation in pulmonary function response to air pollution episodes.

PubMed Central

Brunekreef, B; Kinney, P L; Ware, J H; Dockery, D; Speizer, F E; Spengler, J D; Ferris, B G

1991-01-01

The Clean Air Act requires that sensitive subgroups of exposed populations be protected from adverse health effects of air pollution exposure. Hence, data suggesting the existence of sensitive subgroups can have an important impact on regulatory decisions. Some investigators have interpreted differences among individuals in observed pulmonary function response to air pollution episodes as evidence that individuals differ in their sensitivity. An alternative explanation is that the differences are due entirely to normal variation in repeated pulmonary function measurements. This paper investigates this question by reanalyzing data from three studies of children exposed to air pollution episodes to determine whether the observed variability in pulmonary function response indicates differences in sensitivity or natural interoccasion variability. One study investigated exposures to total suspended particulates (TSP), the other two investigated exposure to ozone. In all studies, each child's response to air pollution exposures was summarized by regressing that child's set of pulmonary function measurements on the air pollution concentrations on the day or days before measurement. The within-child and between-child variances of these slopes were used to test the hypothesis of variable sensitivity. Regression slopes did not vary significantly among children exposed to episodes of high TSP concentration, but there was evidence of heterogeneity in both studies of ozone exposures. The finding of heterogeneous response to ozone exposure is consistent with the epidemiologic and chamber studies of ozone exposures, but the lack of evidence for heterogeneous response to TSP exposures implies that observed variation in response can be explained by sampling variability rather than the presence of sensitive subgroup. PMID:2050060

Functional characterization of blue-light-induced responses and PHOTOTROPIN 1 gene in Welwitschia mirabilis.

PubMed

Ishishita, Kazuhiro; Suetsugu, Noriyuki; Hirose, Yuki; Higa, Takeshi; Doi, Michio; Wada, Masamitsu; Matsushita, Tomonao; Gotoh, Eiji

2016-03-01

The blue light (BL) receptor phototropin (phot) is specifically found in green plants; it regulates various BL-induced responses such as phototropism, chloroplast movement, stomatal opening, and leaf flattening. In Arabidopsis thaliana, two phototropins--phot1 and phot2--respond to blue light in overlapping but distinct ways. These BL-receptor-mediated responses enhance the photosynthetic activity of plants under weak light and minimize photodamage under strong light conditions. Welwitschia mirabilis Hook.f. found in the Namib Desert, and it has adapted to severe environmental stresses such as limiting water and strong sunlight. Although the plant has physiologically and ecologically unique features, it is unknown whether phototropin is functional in this plant. In this study, we assessed the functioning of phot-mediated BL responses in W. mirabilis. BL-dependent phototropism and stomatal opening was observed but light-dependent chloroplast movement was not detected. We performed a functional analysis of the PHOT1 gene of W. mirabilis, WmPHOT1, in Arabidopsis thaliana. We generated transgenic A. thaliana lines expressing WmPHOT1 in a phot1 phot2 double mutant background. Several Wmphot1 transgenic plants showed normal growth, although phot1 phot2 double mutant plants showed stunted growth. Furthermore, Wmphot1 transgenic plants showed normal phot1-mediated responses including phototropism, chloroplast accumulation, stomatal opening, and leaf flattening, but lacked the chloroplast avoidance response that is specifically mediated by phot2. Thus, our findings indicate that W. mirabilis possesses typical phot-mediated BL responses that were at least partially mediated by functional phototropin 1, an ortholog of Atphot1.
Gender-related Changes in Dorsal Hand and Foot Vein Function Following 60 Days of Head Down Bed Rest

NASA Technical Reports Server (NTRS)

Westby, Christian M.; Phillips, Tiffany; Stenger, Michael B.; Platts, Steven H.

2009-01-01

It is well known that female astronauts are more likely to experience post-flight orthostatic hypotension and presyncope compared to male astronauts. It has been suggested that the disproportionally higher incidence of presyncope (83% of female vs. 20% male crewmembers) may be due to sex-related differences in vascular function between the upper and lower limbs. However, much of this evidence is specific to changes in resistance vessels. Given that more than 70% of the circulating blood volume resides in compliance vessels, it is conceivable that even small changes in venous function may contribute to post-flight orthostatic hypotension. In spite of this, little is currently known regarding the influence of microgravity exposure on venous function between males and females. PURPOSE: To determine the influence of 60 days of HDBR on dorsal foot and hand vein function between healthy males (M) and females (F). METHODS: Using 2-D ultrasound, dorsal hand and foot vein diameter responses to intravenous infusions phenylephrine (PE), acetylcholine (ACh), and nitroglycerine (NTG) were determined in 26 adults; 10 females (age:37 +/- 2 yr ) and 16 males (age:34 +/- 2 yr ). Changes in venous function were calculated as the difference between diameter at baseline and following each venoactive drug. Differences in venous function between limb and sexes across HDBR were determined using mixed-effects linear regression. RESULTS: In response to 60 days of HDBR, the change in venousconstrictor response to PE in the dorsal hand veins was not significantly different between M and F. Interestingly, the change in constrictor response in the dorsal foot veins (compared to pre HDBR) was approximately 30% greater in the F, whereas the constrictor response was approximately 45% less in the M (p=0.026). HDBR had no influence on the change in dilator response to ACh, or NTG between M and F and between vascular beds. CONCLUSION: These results demonstrate that 60 days of HDBR contributes to sex-related differences in venous function. Importantly, the changes are specific to dorsal foot veins and do not appear to be related to changes in endothelial or smooth muscle function. Previous data from our laboratory indicate that females have an impaired sympathetic response following HDBR. However, the results from the current investigation imply that F maintain the ability to respond to sympathetic stimulation but may not be able to adequately activate a proper response following HDBR.
Numerical integration of detector response functions via Monte Carlo simulations

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

Kelly, Keegan John; O'Donnell, John M.; Gomez, Jaime A.

Calculations of detector response functions are complicated because they include the intricacies of signal creation from the detector itself as well as a complex interplay between the detector, the particle-emitting target, and the entire experimental environment. As such, these functions are typically only accessible through time-consuming Monte Carlo simulations. Furthermore, the output of thousands of Monte Carlo simulations can be necessary in order to extract a physics result from a single experiment. Here we describe a method to obtain a full description of the detector response function using Monte Carlo simulations. We also show that a response function calculated inmore » this way can be used to create Monte Carlo simulation output spectra a factor of ~1000× faster than running a new Monte Carlo simulation. A detailed discussion of the proper treatment of uncertainties when using this and other similar methods is provided as well. Here, this method is demonstrated and tested using simulated data from the Chi-Nu experiment, which measures prompt fission neutron spectra at the Los Alamos Neutron Science Center.« less
Nonparametric Hierarchical Bayesian Model for Functional Brain Parcellation

PubMed Central

Lashkari, Danial; Sridharan, Ramesh; Vul, Edward; Hsieh, Po-Jang; Kanwisher, Nancy; Golland, Polina

2011-01-01

We develop a method for unsupervised analysis of functional brain images that learns group-level patterns of functional response. Our algorithm is based on a generative model that comprises two main layers. At the lower level, we express the functional brain response to each stimulus as a binary activation variable. At the next level, we define a prior over the sets of activation variables in all subjects. We use a Hierarchical Dirichlet Process as the prior in order to simultaneously learn the patterns of response that are shared across the group, and to estimate the number of these patterns supported by data. Inference based on this model enables automatic discovery and characterization of salient and consistent patterns in functional signals. We apply our method to data from a study that explores the response of the visual cortex to a collection of images. The discovered profiles of activation correspond to selectivity to a number of image categories such as faces, bodies, and scenes. More generally, our results appear superior to the results of alternative data-driven methods in capturing the category structure in the space of stimuli. PMID:21841977
Numerical integration of detector response functions via Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Kelly, K. J.; O'Donnell, J. M.; Gomez, J. A.; Taddeucci, T. N.; Devlin, M.; Haight, R. C.; White, M. C.; Mosby, S. M.; Neudecker, D.; Buckner, M. Q.; Wu, C. Y.; Lee, H. Y.

2017-09-01

Calculations of detector response functions are complicated because they include the intricacies of signal creation from the detector itself as well as a complex interplay between the detector, the particle-emitting target, and the entire experimental environment. As such, these functions are typically only accessible through time-consuming Monte Carlo simulations. Furthermore, the output of thousands of Monte Carlo simulations can be necessary in order to extract a physics result from a single experiment. Here we describe a method to obtain a full description of the detector response function using Monte Carlo simulations. We also show that a response function calculated in this way can be used to create Monte Carlo simulation output spectra a factor of ∼ 1000 × faster than running a new Monte Carlo simulation. A detailed discussion of the proper treatment of uncertainties when using this and other similar methods is provided as well. This method is demonstrated and tested using simulated data from the Chi-Nu experiment, which measures prompt fission neutron spectra at the Los Alamos Neutron Science Center.
Numerical integration of detector response functions via Monte Carlo simulations

DOE PAGES

Kelly, Keegan John; O'Donnell, John M.; Gomez, Jaime A.; ...

2017-06-13

Calculations of detector response functions are complicated because they include the intricacies of signal creation from the detector itself as well as a complex interplay between the detector, the particle-emitting target, and the entire experimental environment. As such, these functions are typically only accessible through time-consuming Monte Carlo simulations. Furthermore, the output of thousands of Monte Carlo simulations can be necessary in order to extract a physics result from a single experiment. Here we describe a method to obtain a full description of the detector response function using Monte Carlo simulations. We also show that a response function calculated inmore » this way can be used to create Monte Carlo simulation output spectra a factor of ~1000× faster than running a new Monte Carlo simulation. A detailed discussion of the proper treatment of uncertainties when using this and other similar methods is provided as well. Here, this method is demonstrated and tested using simulated data from the Chi-Nu experiment, which measures prompt fission neutron spectra at the Los Alamos Neutron Science Center.« less
Increased auditory startle reflex in children with functional abdominal pain.

PubMed

Bakker, Mirte J; Boer, Frits; Benninga, Marc A; Koelman, Johannes H T M; Tijssen, Marina A J

2010-02-01

To test the hypothesis that children with abdominal pain-related functional gastrointestinal disorders have a general hypersensitivity for sensory stimuli. Auditory startle reflexes were assessed in 20 children classified according to Rome III classifications of abdominal pain-related functional gastrointestinal disorders (13 irritable bowel syndrome [IBS], 7 functional abdominal pain syndrome; mean age, 12.4 years; 15 girls) and 23 control subjects (14 girls; mean age, 12.3 years) using a case-control design. The activity of 6 left-sided muscles and the sympathetic skin response were obtained by an electromyogram. We presented sudden loud noises to the subjects through headphones. Both the combined response of 6 muscles and the blink response proved to be significantly increased in patients with abdominal pain compared with control subjects. A significant increase of the sympathetic skin response was not found. Comorbid anxiety disorders (8 patients with abdominal pain) or Rome III subclassification did not significantly affect these results. This study demonstrates an objective hyperresponsivity to nongastrointestinal stimuli. Children with abdominal pain-related functional gastrointestinal disorders may have a generalized hypersensitivity of the central nervous system. Copyright 2010 Mosby, Inc. All rights reserved.
Test procedures and performance measures sensitive to automobile steering dynamics. [considering operator/vehicle responses

NASA Technical Reports Server (NTRS)

Klein, R. H.; Mcruer, D. T.; Weir, D.

1975-01-01

A maneuver complex and related performance measures used to evaluate driver/vehicle system responses as effected by variations in the directional response characteristics of passenger cars are described. The complex consists of normal and emergency maneuvers (including random and discrete disturbances) which, taken as a whole, represent all classes of steering functions and all modes of driver response behavior. Measures of driver/vehicle system response and performance in regulation tasks included direct describing function measurements and rms yaw velocity. In transient maneuvers, measures such as steering activity and cone strikes were used.
Conceptual DFT: the chemical relevance of higher response functions.

PubMed

Geerlings, P; De Proft, F

2008-06-07

In recent years conceptual density functional theory offered a perspective for the interpretation/prediction of experimental/theoretical reactivity data on the basis of a series of response functions to perturbations in the number of electrons and/or external potential. This approach has enabled the sharp definition and computation, from first principles, of a series of well-known but sometimes vaguely defined chemical concepts such as electronegativity and hardness. In this contribution, a short overview of the shortcomings of the simplest, first order response functions is illustrated leading to a description of chemical bonding in a covalent interaction in terms of interacting atoms or groups, governed by electrostatics with the tendency to polarize bonds on the basis of electronegativity differences. The second order approach, well known until now, introduces the hardness/softness and Fukui function concepts related to polarizability and frontier MO theory, respectively. The introduction of polarizability/softness is also considered in a historical perspective in which polarizability was, with some exceptions, mainly put forward in non covalent interactions. A particular series of response functions, arising when the changes in the external potential are solely provoked by changes in nuclear configurations (the "R-analogues") are also systematically considered. The main part of the contribution is devoted to third order response functions which, at first sight, may be expected not to yield chemically significant information, as turns out to be for the hyperhardness. A counterexample is the dual descriptor and its R analogue, the initial hardness response, which turns out to yield a firm basis to regain the Woodward-Hoffmann rules for pericyclic reactions based on a density-only basis, i.e. without involving the phase, sign, symmetry of the wavefunction. Even the second order nonlinear response functions are shown possibly to bear interesting information, e.g. on the local and global polarizability. Its derivatives may govern the influence of charge on the polarizability, the R-analogues being the nuclear Fukui function and the quadratic and cubic force constants. Although some of the higher order derivatives may be difficult to evaluate a comparison with the energy expansion used in spectroscopy in terms of nuclear displacements, nuclear magnetic moments, electric and magnetic fields leads to the conjecture that, certainly cross terms may contain new, intricate information for understanding chemical reactivity.
Non-linear non-local molecular electrodynamics with nano-optical fields.

PubMed

Chernyak, Vladimir Y; Saurabh, Prasoon; Mukamel, Shaul

2015-10-28

The interaction of optical fields sculpted on the nano-scale with matter may not be described by the dipole approximation since the fields may vary appreciably across the molecular length scale. Rather than incrementally adding higher multipoles, it is advantageous and more physically transparent to describe the optical process using non-local response functions that intrinsically include all multipoles. We present a semi-classical approach for calculating non-local response functions based on the minimal coupling Hamiltonian. The first, second, and third order response functions are expressed in terms of correlation functions of the charge and the current densities. This approach is based on the gauge invariant current rather than the polarization, and on the vector potential rather than the electric and magnetic fields.
Frequency response function (FRF) based updating of a laser spot welded structure

NASA Astrophysics Data System (ADS)

Zin, M. S. Mohd; Rani, M. N. Abdul; Yunus, M. A.; Sani, M. S. M.; Wan Iskandar Mirza, W. I. I.; Mat Isa, A. A.

2018-04-01

The objective of this paper is to present frequency response function (FRF) based updating as a method for matching the finite element (FE) model of a laser spot welded structure with a physical test structure. The FE model of the welded structure was developed using CQUAD4 and CWELD element connectors, and NASTRAN was used to calculate the natural frequencies, mode shapes and FRF. Minimization of the discrepancies between the finite element and experimental FRFs was carried out using the exceptional numerical capability of NASTRAN Sol 200. The experimental work was performed under free-free boundary conditions using LMS SCADAS. Avast improvement in the finite element FRF was achieved using the frequency response function (FRF) based updating with two different objective functions proposed.
76 FR 62420 - Statement of Organization, Functions and Delegations of Authority

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-07

... leadership, consultation, training, and management services for HRSA's enterprise computing environment; (2... responsibility with improved security management capabilities and improved alignment of current security... responsible for the organization, management, and administrative functions necessary to carry out the...
7 CFR 11.22 - Functions.

Code of Federal Regulations, 2010 CFR

2010-01-01

.... (a) Director. Provides executive direction for NAD. The Director is responsible for developing and... respond to all FOIA requests concerning appeal decisions and case records maintained by NAD. (b) Deputy Director for Hearings and Administration. Responsible for all administrative functions of NAD, including...
Cole-Davidson dynamics of simple chain models.

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

Dotson, Taylor C.; McCoy, John Dwane; Adolf, Douglas Brian

2008-10-01

Rotational relaxation functions of the end-to-end vector of short, freely jointed and freely rotating chains were determined from molecular dynamics simulations. The associated response functions were obtained from the one-sided Fourier transform of the relaxation functions. The Cole-Davidson function was used to fit the response functions with extensive use being made of Cole-Cole plots in the fitting procedure. For the systems studied, the Cole-Davidson function provided remarkably accurate fits [as compared to the transform of the Kohlrausch-Williams-Watts (KWW) function]. The only appreciable deviations from the simulation results were in the high frequency limit and were due to ballistic or freemore » rotation effects. The accuracy of the Cole-Davidson function appears to be the result of the transition in the time domain from stretched exponential behavior at intermediate time to single exponential behavior at long time. Such a transition can be explained in terms of a distribution of relaxation times with a well-defined longest relaxation time. Since the Cole-Davidson distribution has a sharp cutoff in relaxation time (while the KWW function does not), it makes sense that the Cole-Davidson would provide a better frequency-domain description of the associated response function than the KWW function does.« less
Improved response functions for gamma-ray skyshine analyses

NASA Astrophysics Data System (ADS)

Shultis, J. K.; Faw, R. E.; Deng, X.

1992-09-01

A computationally simple method, based on line-beam response functions, is refined for estimating gamma skyshine dose rates. Critical to this method is the availability of an accurate approximation for the line-beam response function (LBRF). In this study, the LBRF is evaluated accurately with the point-kernel technique using recent photon interaction data. Various approximations to the LBRF are considered, and a three parameter formula is selected as the most practical approximation. By fitting the approximating formula to point-kernel results, a set of parameters is obtained that allows the LBRF to be quickly and accurately evaluated for energies between 0.01 and 15 MeV, for source-to-detector distances from 1 to 3000 m, and for beam angles from 0 to 180 degrees. This re-evaluation of the approximate LBRF gives better accuracy, especially at low energies, over a greater source-to-detector range than do previous LBRF approximations. A conical beam response function is also introduced for application to skyshine sources that are azimuthally symmetric about a vertical axis. The new response functions are then applied to three simple skyshine geometries (an open silo geometry, an infinite wall, and a rectangular four-wall building) and the results are compared to previous calculations and benchmark data.
A meta-analysis of context-dependency in plant response to inoculation with mycorrhizal fungi.

PubMed

Hoeksema, Jason D; Chaudhary, V Bala; Gehring, Catherine A; Johnson, Nancy Collins; Karst, Justine; Koide, Roger T; Pringle, Anne; Zabinski, Catherine; Bever, James D; Moore, John C; Wilson, Gail W T; Klironomos, John N; Umbanhowar, James

2010-03-01

Ecology Letters (2010) 13: 394-407 Abstract Mycorrhizal fungi influence plant growth, local biodiversity and ecosystem function. Effects of the symbiosis on plants span the continuum from mutualism to parasitism. We sought to understand this variation in symbiotic function using meta-analysis with information theory-based model selection to assess the relative importance of factors in five categories: (1) identity of the host plant and its functional characteristics, (2) identity and type of mycorrhizal fungi (arbuscular mycorrhizal vs. ectomycorrhizal), (3) soil fertility, (4) biotic complexity of the soil and (5) experimental location (laboratory vs. field). Across most subsets of the data, host plant functional group and N-fertilization were surprisingly much more important in predicting plant responses to mycorrhizal inoculation ('plant response') than other factors. Non-N-fixing forbs and woody plants and C(4) grasses responded more positively to mycorrhizal inoculation than plants with N-fixing bacterial symbionts and C(3) grasses. In laboratory studies of the arbuscular mycorrhizal symbiosis, plant response was more positive when the soil community was more complex. Univariate analyses supported the hypothesis that plant response is most positive when plants are P-limited rather than N-limited. These results emphasize that mycorrhizal function depends on both abiotic and biotic context, and have implications for plant community theory and restoration ecology.
The impact of executive function on response to cognitive behavioral therapy in late-life depression.

PubMed

Goodkind, Madeleine S; Gallagher-Thompson, Dolores; Thompson, Larry W; Kesler, Shelli R; Anker, Lauren; Flournoy, John; Berman, Mika P; Holland, Jason M; O'Hara, Ruth M

2016-04-01

Late-life depression (LLD) is a common and debilitating condition among older adults. Cognitive behavioral therapy (CBT) has strong empirical support for the treatment of depression in all ages, including in LLD. In teaching patients to identify, monitor, and challenge negative patterns in their thinking, CBT for LLD relies heavily on cognitive processes and, in particular, executive functioning, such as planning, sequencing, organizing, and selectively inhibiting information. It may be that the effectiveness of CBT lies in its ability to train these cognitive areas. Participants with LLD completed a comprehensive neuropsychological battery before enrolling in CBT. The current study examined the relationship between neuropsychological function prior to treatment and response to CBT. When using three baseline measures of executive functioning that quantify set shifting, cognitive flexibility, and response inhibition to predict treatment response, only baseline Wisconsin Card Sort Task performance was associated with a significant drop in depression symptoms after CBT. Specifically, worse performance on the Wisconsin Card Sort Task was associated with better treatment response. These results suggest that CBT, which teaches cognitive techniques for improving psychiatric symptoms, may be especially beneficial in LLD if relative weaknesses in specific areas of executive functioning are present. Copyright © 2015 John Wiley & Sons, Ltd.
Tapered Optical Fiber Functionalized with Palladium Nanoparticles by Drop Casting and Laser Radiation for H2 and Volatile Organic Compounds Sensing Purposes

PubMed Central

González-Sierra, Nancy Elizabeth; Gómez-Pavón, Luz del Carmen; Pérez-Sánchez, Gerardo Francisco; Luis-Ramos, Arnulfo; Zaca-Morán, Plácido; Chávez-Ramírez, Fernando

2017-01-01

A comparative study on the sensing properties of a tapered optical fiber pristine and functionalized with the palladium nanoparticles to hydrogen and volatile organic compounds (VOCs), is presented. The sensor response and, response/recovery times were extracted from the measurements of the transient response of the device. The tapered optical fiber sensor was fabricated using a single-mode optical fiber by the flame-brushing technique. Functionalization of the optical fiber was performed using an aqueous solution of palladium chloride by drop-casting technique assisted for laser radiation. The detection principle of the sensor is based on the changes in the optical properties of palladium nanoparticles when exposed to reducing gases, which causes a variation in the absorption of evanescent waves. A continuous wave laser diode operating at 1550 nm is used for the sensor characterization. The sensor functionalized with palladium nanoparticles by this technique is viable for the sensing of hydrogen and VOCs, since it shows an enhancement in sensor response and response time compared to the sensor based on the pristine optical microfiber. The results show that the fabricated sensor is competitive with other fiber optic sensors functionalized with palladium nanoparticles to the hydrogen. PMID:28878161
Polyfunctional analysis of Gag and Nef specific CD8+ T-cell responses in HIV-1 infected Indian individuals.

PubMed

Mendiratta, Sanjay; Vajpayee, Madhu; Mojumdar, Kamalika; Chauhan, Neeraj K; Sreenivas, Vishnubhatla

2011-02-01

Polyfunctional CD8+ T-cells have been described as most competent in controlling viral replication. We studied the impact of antigen persistence on the polyfunctional immune responses of CD8+ T-lymphocytes to HIV Gag and Nef peptides and polyclonal stimuli in 40 ART naïve HIV infected individuals and analyzed the alterations in T-cell functionality in early and late stages of infection. Significantly elevated level of global response and polyfunctional profile of CD8+ T-cells were observed to polyclonal stimulation, than HIV specific antigens in chronically infected individuals. However no key differences were observed in CD8+ T-cell functional profile in any of the 15 unique subsets for Gag and Nef specific antigens. The subjects in early stage of infection (defined as a gap of 6 months or less between seroconversion and enrolment and with no apparent clinical symptoms) had a higher degree of response functionality (4+ or 3+ different functions simultaneously) than in the late stage infection (defined as time duration since seroconversion greater than 6 months). The data suggest that persistence of antigen during chronic infection leads to functional impairment of HIV specific responses. Copyright Â© 2010 Elsevier Ltd. All rights reserved.
A synthesis of AOT40-based response functions and critical levels of ozone for agricultural and horticultural crops

NASA Astrophysics Data System (ADS)

Mills, G.; Buse, A.; Gimeno, B.; Bermejo, V.; Holland, M.; Emberson, L.; Pleijel, H.

Crop-response data from over 700 published papers and conference proceedings have been analysed with the aim of establishing ozone dose-response functions for a wide range of European agricultural and horticultural crops. Data that met rigorous selection criteria (e.g. field-based, ozone concentrations within European range, full season exposure period) were used to derive AOT40-yield response functions for 19 crops by first converting the published ozone concentration data into AOT40 (AOT40 is the hourly mean ozone concentration accumulated over a threshold ozone concentration of 40 ppb during daylight hours, units ppm h). For any individual crop, there were no significant differences in the linear response functions derived for experiments conducted in the USA or Europe, or for individual cultivars. Three statistically independent groups were identified: ozone sensitive crops (wheat, water melon, pulses, cotton, turnip, tomato, onion, soybean and lettuce); moderately sensitive crops (sugar beet, potato, oilseed rape, tobacco, rice, maize, grape and broccoli) and ozone resistant (barley and fruit represented by plum and strawberry). Critical levels of a 3 month AOT40 of 3 ppm h and a 3.5 month AOT40 of 6 ppm h were derived from the functions for wheat and tomato, respectively.

The Richness of Task-Evoked Hemodynamic Responses Defines a Pseudohierarchy of Functionally Meaningful Brain Networks

PubMed Central

Orban, Pierre; Doyon, Julien; Petrides, Michael; Mennes, Maarten; Hoge, Richard; Bellec, Pierre

2015-01-01

Functional magnetic resonance imaging can measure distributed and subtle variations in brain responses associated with task performance. However, it is unclear whether the rich variety of responses observed across the brain is functionally meaningful and consistent across individuals. Here, we used a multivariate clustering approach that grouped brain regions into clusters based on the similarity of their task-evoked temporal responses at the individual level, and then established the spatial consistency of these individual clusters at the group level. We observed a stable pseudohierarchy of task-evoked networks in the context of a delayed sequential motor task, where the fractionation of networks was driven by a gradient of involvement in motor sequence preparation versus execution. In line with theories about higher-level cognitive functioning, this gradient evolved in a rostro-caudal manner in the frontal lobe. In addition, parcellations in the cerebellum and basal ganglia matched with known anatomical territories and fiber pathways with the cerebral cortex. These findings demonstrate that subtle variations in brain responses associated with task performance are systematic enough across subjects to define a pseudohierarchy of task-evoked networks. Such networks capture meaningful functional features of brain organization as shaped by a given cognitive context. PMID:24729172
Tapered Optical Fiber Functionalized with Palladium Nanoparticles by Drop Casting and Laser Radiation for H₂ and Volatile Organic Compounds Sensing Purposes.

PubMed

González-Sierra, Nancy Elizabeth; Gómez-Pavón, Luz Del Carmen; Pérez-Sánchez, Gerardo Francisco; Luis-Ramos, Arnulfo; Zaca-Morán, Plácido; Muñoz-Pacheco, Jesús Manuel; Chávez-Ramírez, Francisco

2017-09-06

A comparative study on the sensing properties of a tapered optical fiber pristine and functionalized with the palladium nanoparticles to hydrogen and volatile organic compounds (VOCs), is presented. The sensor response and, response/recovery times were extracted from the measurements of the transient response of the device. The tapered optical fiber sensor was fabricated using a single-mode optical fiber by the flame-brushing technique. Functionalization of the optical fiber was performed using an aqueous solution of palladium chloride by drop-casting technique assisted for laser radiation. The detection principle of the sensor is based on the changes in the optical properties of palladium nanoparticles when exposed to reducing gases, which causes a variation in the absorption of evanescent waves. A continuous wave laser diode operating at 1550 nm is used for the sensor characterization. The sensor functionalized with palladium nanoparticles by this technique is viable for the sensing of hydrogen and VOCs, since it shows an enhancement in sensor response and response time compared to the sensor based on the pristine optical microfiber. The results show that the fabricated sensor is competitive with other fiber optic sensors functionalized with palladium nanoparticles to the hydrogen.
Improved response functions for gamma-ray skyshine analyses

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

Shultis, J.K.; Faw, R.E.; Deng, X.

1992-09-01

A computationally simple method, based on line-beam response functions, is refined for estimating gamma skyshine dose rates. Critical to this method is the availability of an accurate approximation for the line-beam response function (LBRF). In this study the LBRF is evaluated accurately with the point-kernel technique using recent photon interaction data. Various approximations to the LBRF are considered, and a three parameter formula is selected as the most practical approximation. By fitting the approximating formula to point-kernel results, a set of parameters is obtained that allows the LBRF to be quickly and accurately evaluated for energies between 0.01 and 15more » MeV, for source-to-detector distances from 1 to 3000 m, and for beam angles from 0 to 180 degrees. This reevaluation of the approximate LBRF gives better accuracy, especially at low energies, over a greater source-to-detector range than do previous LBRF approximations. A conical beam response function is also introduced for application to skyshine sources that are azimuthally symmetric about a vertical axis. The new response functions are then applied to three simple skyshine geometries (an open silo geometry, an infinite wall, and a rectangular four-wall building) and the results compared to previous calculations and benchmark data.« less
Oscillatory frontal theta responses are increased upon bisensory stimulation.

PubMed

Sakowitz, O W; Schürmann, M; Başar, E

2000-05-01

To investigate the functional correlation of oscillatory EEG components with the interaction of sensory modalities following simultaneous audio-visual stimulation. In an experimental study (15 subjects) we compared auditory evoked potentials (AEPs) and visual evoked potentials (VEPs) to bimodal evoked potentials (BEPs; simultaneous auditory and visual stimulation). BEPs were assumed to be brain responses to complex stimuli as a marker for intermodal associative functioning. Frequency domain analysis of these EPs showed marked theta-range components in response to bimodal stimulation. These theta components could not be explained by linear addition of the unimodal responses in the time domain. Considering topography the increased theta-response showed a remarkable frontality in proximity to multimodal association cortices. Referring to methodology we try to demonstrate that, even if various behavioral correlates of brain oscillations exist, common patterns can be extracted by means of a systems-theoretical approach. Serving as an example of functionally relevant brain oscillations, theta responses could be interpreted as an indicator of associative information processing.
Attentional and physiological processing of food images in functional dyspepsia patients: A pilot study.

PubMed

Lee, In-Seon; Preissl, Hubert; Giel, Katrin; Schag, Kathrin; Enck, Paul

2018-01-23

The food-related behavior of functional dyspepsia has been attracting more interest of late. This pilot study aims to provide evidence of the physiological, emotional, and attentional aspects of food processing in functional dyspepsia patients. The study was performed in 15 functional dyspepsia patients and 17 healthy controls after a standard breakfast. We measured autonomic nervous system activity using skin conductance response and heart rate variability, emotional response using facial electromyography, and visual attention using eyetracking during the visual stimuli of food/non-food images. In comparison to healthy controls, functional dyspepsia patients showed a greater craving for food, a decreased intake of food, more dyspeptic symptoms, lower pleasantness rating of food images (particularly of high fat), decreased low frequency/high frequency ratio of heart rate variability, and suppressed total processing time of food images. There were no significant differences of skin conductance response and facial electromyography data between groups. The results suggest that high level cognitive functions rather than autonomic and emotional mechanisms are more liable to function differently in functional dyspepsia patients. Abnormal dietary behavior, reduced subjective rating of pleasantness and visual attention to food should be considered as important pathophysiological characteristics in functional dyspepsia.
The Adaptive Calibration Model of stress responsivity

PubMed Central

Ellis, Bruce J.; Shirtcliff, Elizabeth A.

2010-01-01

This paper presents the Adaptive Calibration Model (ACM), an evolutionary-developmental theory of individual differences in the functioning of the stress response system. The stress response system has three main biological functions: (1) to coordinate the organism’s allostatic response to physical and psychosocial challenges; (2) to encode and filter information about the organism’s social and physical environment, mediating the organism’s openness to environmental inputs; and (3) to regulate the organism’s physiology and behavior in a broad range of fitness-relevant areas including defensive behaviors, competitive risk-taking, learning, attachment, affiliation and reproductive functioning. The information encoded by the system during development feeds back on the long-term calibration of the system itself, resulting in adaptive patterns of responsivity and individual differences in behavior. Drawing on evolutionary life history theory, we build a model of the development of stress responsivity across life stages, describe four prototypical responsivity patterns, and discuss the emergence and meaning of sex differences. The ACM extends the theory of biological sensitivity to context (BSC) and provides an integrative framework for future research in the field. PMID:21145350
Water immersion decreases sympathetic skin response during color–word Stroop test

PubMed Central

Yamazaki, Yudai; Takahashi, Akari; Uetake, Yoshihito; Nakano, Saki; Iguchi, Kaho; Baba, Yasuhiro; Nara, Rio; Shimoyama, Yoshimitsu

2017-01-01

Water immersion alters the autonomic nervous system (ANS) response in humans. The effect of water immersion on executive function and ANS responses related to executive function tasks was unknown. Therefore, this study aimed to determine whether water immersion alters ANS response during executive tasks. Fourteen healthy participants performed color–word-matching Stroop tasks before and after non-immersion and water immersion intervention for 15 min in separate sessions. The Stroop task-related skin conductance response (SCR) was measured during every task. In addition, the skin conductance level (SCL) and electrocardiograph signals were measured over the course of the experimental procedure. The main findings of the present study were as follows: 1) water immersion decreased the executive task-related sympathetic nervous response, but did not affect executive function as evaluated by Stroop tasks, and 2) decreased SCL induced by water immersion was maintained for at least 15 min after water immersion. In conclusion, the present results suggest that water immersion decreases the sympathetic skin response during the color–word Stroop test without altering executive performance. PMID:28742137
WRKY transcription factors in plant responses to stresses.

PubMed

Jiang, Jingjing; Ma, Shenghui; Ye, Nenghui; Jiang, Ming; Cao, Jiashu; Zhang, Jianhua

2017-02-01

The WRKY gene family is among the largest families of transcription factors (TFs) in higher plants. By regulating the plant hormone signal transduction pathway, these TFs play critical roles in some plant processes in response to biotic and abiotic stress. Various bodies of research have demonstrated the important biological functions of WRKY TFs in plant response to different kinds of biotic and abiotic stresses and working mechanisms. However, very little summarization has been done to review their research progress. Not just important TFs function in plant response to biotic and abiotic stresses, WRKY also participates in carbohydrate synthesis, senescence, development, and secondary metabolites synthesis. WRKY proteins can bind to W-box (TGACC (A/T)) in the promoter of its target genes and activate or repress the expression of downstream genes to regulate their stress response. Moreover, WRKY proteins can interact with other TFs to regulate plant defensive responses. In the present review, we focus on the structural characteristics of WRKY TFs and the research progress on their functions in plant responses to a variety of stresses. © 2016 Institute of Botany, Chinese Academy of Sciences.
Water immersion decreases sympathetic skin response during color-word Stroop test.

PubMed

Sato, Daisuke; Yamazaki, Yudai; Takahashi, Akari; Uetake, Yoshihito; Nakano, Saki; Iguchi, Kaho; Baba, Yasuhiro; Nara, Rio; Shimoyama, Yoshimitsu

2017-01-01

Water immersion alters the autonomic nervous system (ANS) response in humans. The effect of water immersion on executive function and ANS responses related to executive function tasks was unknown. Therefore, this study aimed to determine whether water immersion alters ANS response during executive tasks. Fourteen healthy participants performed color-word-matching Stroop tasks before and after non-immersion and water immersion intervention for 15 min in separate sessions. The Stroop task-related skin conductance response (SCR) was measured during every task. In addition, the skin conductance level (SCL) and electrocardiograph signals were measured over the course of the experimental procedure. The main findings of the present study were as follows: 1) water immersion decreased the executive task-related sympathetic nervous response, but did not affect executive function as evaluated by Stroop tasks, and 2) decreased SCL induced by water immersion was maintained for at least 15 min after water immersion. In conclusion, the present results suggest that water immersion decreases the sympathetic skin response during the color-word Stroop test without altering executive performance.
Thrips developmental stage-specific transcriptome response to tomato spotted wilt virus during the virus infection cycle in Frankliniella occidentalis, the primary vector.

PubMed

Schneweis, Derek J; Whitfield, Anna E; Rotenberg, Dorith

2017-01-01

Tomato spotted wilt virus (TSWV) is transmitted by Frankliniella occidentalis in a circulative-propagative manner. Little is known about thrips vector response to TSWV during the infection process from larval acquisition to adult inoculation of plants. Whole-body transcriptome response to virus infection was determined for first-instar larval, pre-pupal and adult thrips using RNA-Seq. TSWV responsive genes were identified using preliminary sequence of a draft genome of F. occidentalis as a reference and three developmental-stage transcriptomes were assembled. Processes and functions associated with host defense, insect cuticle structure and development, metabolism and transport were perturbed by TSWV infection as inferred by ontologies of responsive genes. The repertoire of genes responsive to TSWV varied between developmental stages, possibly reflecting the link between thrips development and the virus dissemination route in the vector. This study provides the foundation for exploration of tissue-specific expression in response to TSWV and functional analysis of thrips gene function. Copyright Â© 2016 Elsevier Inc. All rights reserved.
Intrapixel measurement techniques on large focal plane arrays for astronomical applications: a comparative study

NASA Astrophysics Data System (ADS)

Ketchazo, C.; Viale, T.; Boulade, O.; de la Barrière, F.; Dubreuil, D.; Mugnier, L.; Moreau, V.; Guérineau, N.; Mulet, P.; Druart, G.; Delisle, C.

2017-09-01

The intrapixel response is the signal detected by a single pixel illuminated by a Dirac distribution as a function of the position of this Dirac inside this pixel. It is also known as the pixel response function (PRF). This function measures the sensitivity variation at the subpixel scale and gives a spatial map of the sensitivity across a pixel.
Thermal Density Functional Theory: Time-Dependent Linear Response and Approximate Functionals from the Fluctuation-Dissipation Theorem

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

Pribram-Jones, Aurora; Grabowski, Paul E.; Burke, Kieron

We present that the van Leeuwen proof of linear-response time-dependent density functional theory (TDDFT) is generalized to thermal ensembles. This allows generalization to finite temperatures of the Gross-Kohn relation, the exchange-correlation kernel of TDDFT, and fluctuation dissipation theorem for DFT. Finally, this produces a natural method for generating new thermal exchange-correlation approximations.
Thermal Density Functional Theory: Time-Dependent Linear Response and Approximate Functionals from the Fluctuation-Dissipation Theorem

DOE PAGES

Pribram-Jones, Aurora; Grabowski, Paul E.; Burke, Kieron

2016-06-08

We present that the van Leeuwen proof of linear-response time-dependent density functional theory (TDDFT) is generalized to thermal ensembles. This allows generalization to finite temperatures of the Gross-Kohn relation, the exchange-correlation kernel of TDDFT, and fluctuation dissipation theorem for DFT. Finally, this produces a natural method for generating new thermal exchange-correlation approximations.
Responses of susceptible subpopulations to nitrogen dioxide. Research report, June 1983-January 1988

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

Morrow, P.E.; Utell, M.J.

1989-02-01

Symptom responses and changes in pulmonary function were investigated in people with asthma or chronic obstructive pulmonary disease (COPD) exposed to 0.3 ppm nitrogen dioxide (NO{sub 2}) for four hours. Nonrespiratory-impaired (normal) subjects of comparable ages constituted the control groups. All exposures included periods of exercise and pulmonary function measurements. No significant symptomatic or physiological responses to NO{sub 2} could be detected in either the young or elderly control group. The asthmatic group did not manifest significant reductions in lung function after exposure to 0.3 ppm NO{sub 2}, compared to their preexposure baseline data or to their responses after amore » comparable four-hour exposure to air. During light exercise, subjects with COPD were progressively responsive to 0.3 ppm NO{sub 2}. Subgroup analyses within the asthmatic, COPD, and elderly normal subject groups and intergroup comparisons yielded significant findings and associations.« less
Bioelectronic Sensors and Devices

NASA Astrophysics Data System (ADS)

Reed, Mark

Nanoscale electronic devices have recently enabled the ability to controllably probe biological systems, from the molecular to the cellular level, opening up new applications and understanding of biological function and response. This talk reviews some of the advances in the field, ranging from diagnostic and therapeutic applications, to cellular manipulation and response, to the emulation of biological response. In diagnostics, integrated nanodevice biosensors compatible with CMOS technology have achieved unprecedented sensitivity, enabling a wide range of label-free biochemical and macromolecule sensing applications down to femtomolar concentrations. These systems have demonstrated integrated assays of biomarkers at clinically important concentrations for both diagnostics and as a quantitative tool for drug design and discovery. Cellular level response can also be observed, including immune response function and dynamics. Finally, the field is beginning to create devices that emulate function, and the demonstration of a solid state artificial ion channel will be discussed.
Identifying gnostic predictors of the vaccine response.

PubMed

Haining, W Nicholas; Pulendran, Bali

2012-06-01

Molecular predictors of the response to vaccination could transform vaccine development. They would allow larger numbers of vaccine candidates to be rapidly screened, shortening the development time for new vaccines. Gene-expression based predictors of vaccine response have shown early promise. However, a limitation of gene-expression based predictors is that they often fail to reveal the mechanistic basis of their ability to classify response. Linking predictive signatures to the function of their component genes would advance basic understanding of vaccine immunity and also improve the robustness of vaccine prediction. New analytic tools now allow more biological meaning to be extracted from predictive signatures. Functional genomic approaches to perturb gene expression in mammalian cells permit the function of predictive genes to be surveyed in highly parallel experiments. The challenge for vaccinologists is therefore to use these tools to embed mechanistic insights into predictors of vaccine response. Copyright © 2012 Elsevier Ltd. All rights reserved.
Identifying gnostic predictors of the vaccine response

PubMed Central

Haining, W. Nicholas; Pulendran, Bali

2012-01-01

Molecular predictors of the response to vaccination could transform vaccine development. They would allow larger numbers of vaccine candidates to be rapidly screened, shortening the development time for new vaccines. Gene-expression based predictors of vaccine response have shown early promise. However, a limitation of gene-expression based predictors is that they often fail to reveal the mechanistic basis for their ability to classify response. Linking predictive signatures to the function of their component genes would advance basic understanding of vaccine immunity and also improve the robustness of outcome classification. New analytic tools now allow more biological meaning to be extracted from predictive signatures. Functional genomic approaches to perturb gene expression in mammalian cells permit the function of predictive genes to be surveyed in highly parallel experiments. The challenge for vaccinologists is therefore to use these tools to embed mechanistic insights into predictors of vaccine response. PMID:22633886
The Role of Civil Society Organizations in Monitoring the Global AIDS Response.

PubMed

Smith, Julia; Mallouris, Christoforos; Lee, Kelley; Alfvén, Tobias

2017-07-01

Civil society organizations (CSOs) are recognized as playing an exceptional role in the global AIDS response. However, there is little detailed research to date on how they contribute to specific governance functions. This article uses Haas' framework on global governance functions to map CSO's participation in the monitoring of global commitments to the AIDS response by institutions and states. Drawing on key informant interviews and primary documents, it focuses specifically on CSO participation in Global AIDS Response Progress Reporting and in Global Fund to Fight AIDS, Tuberculosis and Malaria processes. It argues that the AIDS response is unique within global health governance, in that CSOs fulfill both formal and informal monitoring functions, and considers the strengths and weaknesses of these contributions. It concludes that future global health governance arrangements should include provisions and resources for monitoring by CSOs because their participation creates more inclusive global health governance and contributes to strengthening commitments to human rights.
Stimuli-Responsive Polymer Brushes for Flow Control through Nanopores

PubMed Central

Adiga, Shashishekar P.; Brenner, Donald W.

2012-01-01

Responsive polymers attached to the inside of nano/micro-pores have attracted great interest owing to the prospect of designing flow-control devices and signal responsive delivery systems. An intriguing possibility involves functionalizing nanoporous materials with smart polymers to modulate biomolecular transport in response to pH, temperature, ionic concentration, light or electric field. These efforts open up avenues to develop smart medical devices that respond to specific physiological conditions. In this work, an overview of nanoporous materials functionalized with responsive polymers is given. Various examples of pH, temperature and solvent responsive polymers are discussed. A theoretical treatment that accounts for polymer conformational change in response to a stimulus and the associated flow-control effect is presented. PMID:24955529
Attenuation of Frontostriatal Connectivity During Reward Processing Predicts Response to Psychotherapy in Major Depressive Disorder.

PubMed

Walsh, Erin; Carl, Hannah; Eisenlohr-Moul, Tory; Minkel, Jared; Crowther, Andrew; Moore, Tyler; Gibbs, Devin; Petty, Chris; Bizzell, Josh; Smoski, Moria J; Dichter, Gabriel S

2017-03-01

There are few reliable predictors of response to antidepressant treatments. In the present investigation, we examined pretreatment functional brain connectivity during reward processing as a potential predictor of response to Behavioral Activation Treatment for Depression (BATD), a validated psychotherapy that promotes engagement with rewarding stimuli and reduces avoidance behaviors. Thirty-three outpatients with major depressive disorder (MDD) and 20 matched controls completed two runs of the monetary incentive delay task during functional magnetic resonance imaging after which participants with MDD received up to 15 sessions of BATD. Seed-based generalized psychophysiological interaction analyses focused on task-based connectivity across task runs, as well as the attenuation of connectivity from the first to the second run of the task. The average change in Beck Depression Inventory-II scores due to treatment was 10.54 points, a clinically meaningful response. Groups differed in seed-based functional connectivity among multiple frontostriatal regions. Hierarchical linear modeling revealed that improved treatment response to BATD was predicted by greater connectivity between the left putamen and paracingulate gyrus during reward anticipation. In addition, MDD participants with greater attenuation of connectivity between several frontostriatal seeds, and midline subcallosal cortex and left paracingulate gyrus demonstrated improved response to BATD. These findings indicate that pretreatment frontostriatal functional connectivity during reward processing is predictive of response to a psychotherapy modality that promotes improving approach-related behaviors in MDD. Furthermore, connectivity attenuation among reward-processing regions may be a particularly powerful endophenotypic predictor of response to BATD in MDD.

Guanfacine modulates the influence of emotional cues on prefrontal cortex activation for cognitive control.

PubMed

Schulz, Kurt P; Clerkin, Suzanne M; Fan, Jin; Halperin, Jeffrey M; Newcorn, Jeffrey H

2013-03-01

Functional interactions between limbic regions that process emotions and frontal networks that guide response functions provide a substrate for emotional cues to influence behavior. Stimulation of postsynaptic α₂ adrenoceptors enhances the function of prefrontal regions in these networks. However, the impact of this stimulation on the emotional biasing of behavior has not been established. This study tested the effect of the postsynaptic α₂ adrenoceptor agonist guanfacine on the emotional biasing of response execution and inhibition in prefrontal cortex. Fifteen healthy young adults were scanned twice with functional magnetic resonance imaging while performing a face emotion go/no-go task following counterbalanced administration of single doses of oral guanfacine (1 mg) and placebo in a double-blind, cross-over design. Lower perceptual sensitivity and less response bias for sad faces resulted in fewer correct responses compared to happy and neutral faces but had no effect on correct inhibitions. Guanfacine increased the sensitivity and bias selectively for sad faces, resulting in response accuracy comparable to happy and neutral faces, and reversed the valence-dependent variation in response-related activation in left dorsolateral prefrontal cortex (DLPFC), resulting in enhanced activation for response execution cued by sad faces relative to happy and neutral faces, in line with other frontoparietal regions. These results provide evidence that guanfacine stimulation of postsynaptic α₂ adrenoceptors moderates DLPFC activation associated with the emotional biasing of response execution processes. The findings have implications for the α₂ adrenoceptor agonist treatment of attention-deficit hyperactivity disorder.
INCA- INTERACTIVE CONTROLS ANALYSIS

NASA Technical Reports Server (NTRS)

Bauer, F. H.

1994-01-01

The Interactive Controls Analysis (INCA) program was developed to provide a user friendly environment for the design and analysis of linear control systems, primarily feedback control systems. INCA is designed for use with both small and large order systems. Using the interactive graphics capability, the INCA user can quickly plot a root locus, frequency response, or time response of either a continuous time system or a sampled data system. The system configuration and parameters can be easily changed, allowing the INCA user to design compensation networks and perform sensitivity analysis in a very convenient manner. A journal file capability is included. This stores an entire sequence of commands, generated during an INCA session into a file which can be accessed later. Also included in INCA are a context-sensitive help library, a screen editor, and plot windows. INCA is robust to VAX-specific overflow problems. The transfer function is the basic unit of INCA. Transfer functions are automatically saved and are available to the INCA user at any time. A powerful, user friendly transfer function manipulation and editing capability is built into the INCA program. The user can do all transfer function manipulations and plotting without leaving INCA, although provisions are made to input transfer functions from data files. By using a small set of commands, the user may compute and edit transfer functions, and then examine these functions by using the ROOT_LOCUS, FREQUENCY_RESPONSE, and TIME_RESPONSE capabilities. Basic input data, including gains, are handled as single-input single-output transfer functions. These functions can be developed using the function editor or by using FORTRAN- like arithmetic expressions. In addition to the arithmetic functions, special functions are available to 1) compute step, ramp, and sinusoid functions, 2) compute closed loop transfer functions, 3) convert from S plane to Z plane with optional advanced Z transform, and 4) convert from Z plane to W plane and back. These capabilities allow the INCA user to perform block diagram algebraic manipulations quickly for functions in the S, Z, and W domains. Additionally, a versatile digital control capability has been included in INCA. Special plane transformations allow the user to easily convert functions from one domain to another. Other digital control capabilities include: 1) totally independent open loop frequency response analyses on a continuous plant, discrete control system with a delay, 2) advanced Z-transform capability for systems with delays, and 3) multirate sampling analyses. The current version of INCA includes Dynamic Functions (which change when a parameter changes), standard filter generation, PD and PID controller generation, incorporation of the QZ-algorithm (function addition, inverse Laplace), and describing functions that allow the user to calculate the gain and phase characteristics of a nonlinear device. The INCA graphic modes provide the user with a convenient means to document and study frequency response, time response, and root locus analyses. General graphics features include: 1) zooming and dezooming, 2) plot documentation, 3) a table of analytic computation results, 4) multiple curves on the same plot, and 5) displaying frequency and gain information for a specific point on a curve. Additional capabilities in the frequency response mode include: 1) a full complement of graphical methods Bode magnitude, Bode phase, Bode combined magnitude and phase, Bode strip plots, root contour plots, Nyquist, Nichols, and Popov plots; 2) user selected plot scaling; and 3) gain and phase margin calculation and display. In the time response mode, additional capabilities include: 1) support for inverse Laplace and inverse Z transforms, 2) support for various input functions, 3) closed loop response evaluation, 4) loop gain sensitivity analyses, 5) intersample time response for discrete systems using the advanced Z transform, and 6) closed loop time response using mixed plane (S, Z, W) operations with delay. A Graphics mode command was added to the current version of INCA, version 3.13, to produce Metafiles (graphic files) of the currently displayed plot. The metafile can be displayed and edited using the QPLOT Graphics Editor and Replotter for Metafiles (GERM) program included with the INCA package. The INCA program is written in Pascal and FORTRAN for interactive or batch execution and has been implemented on a DEC VAX series computer under VMS. Both source code and executable code are supplied for INCA. Full INCA graphics capabilities are supported for various Tektronix 40xx and 41xx terminals; DEC VT graphics terminals; many PC and Macintosh terminal emulators; TEK014 hardcopy devices such as the LN03 Laserprinter; and bit map graphics external hardcopy devices. Also included for the TEK4510 rasterizer users are a multiple copy feature, a wide line feature, and additional graphics fonts. The INCA program was developed in 1985, Version 2.04 was released in 1986, Version 3.00 was released in 1988, and Version 3.13 was released in 1989. An INCA version 2.0X conversion program is included.
Ca2+ Responses in Enteric Glia are Mediated by Connexin-43 Hemichannels and Modulate Colonic Transit in Mice

PubMed Central

Fried, David; Gomez-Suarez, Roberto A.; Leinninger, Gina M.; Sévigny, Jean; Parpura, Vladimir; Gulbransen, Brian D.

2014-01-01

Background & Aims In the enteric nervous system, neurotransmitters initiate changes in Ca2+ (Ca2+ responses) in glia, but it is not clear how this process affects intestinal function. We investigated whether Ca2+-mediated responses in enteric glial are required to maintain gastrointestinal function. Methods We used in situ Ca2+ imaging to monitor glial Ca2+ responses, which were manipulated with pharmacologic agents or via glia-specific disruption of the gene encoding connexin-43 (Cx43) (hGFAP::creERT2+/−/Cx43f/f mice). Gastrointestinal function was assessed based on pellet output, total gut transit, colonic bead expulsion, and muscle tension recordings. Proteins were localized and quantified by immunohistochemistry, immunoblot, and reverse transcription PCR analyses. Results Ca2+ responses in enteric glia of mice were mediated by Cx43 hemichannels. Cx43 immunoreactivity was confined to enteric glia within the myenteric plexus of the mouse colon; the Cx43 inhibitors carbenoxolone and 43Gap26 inhibited the ability of enteric glia to propagate Ca2+ responses. In vivo attenuation of Ca2+ responses in the enteric glial network slowed gut transit overall and delayed colonic transit—these changes are also observed during normal aging. Altered motility with increasing age was associated with reduced glial Ca2+-mediated responses and changes in glial expression of Cx43 mRNA and protein. Conclusions Ca2+-mediated responses in enteric glia regulate gastrointestinal function in mice. Altered intercellular signaling between enteric glia and neurons might contribute to motility disorders. PMID:24211490
Interactions between the cytomegalovirus promoter and the estrogen response element: implications for design of estrogen-responsive reporter plasmids.

PubMed

Derecka, K; Wang, C K; Flint, A P F

2006-07-01

We aimed to produce an estrogen-responsive reporter plasmid that would permit monitoring of estrogen receptor function in the uterus in vivo. The plasmid pBL-tk-CAT(+)ERE was induced by estrogen in bovine endometrial stromal cells. When the CAT gene was replaced by the secreted alkaline phosphatase SeAP, the resulting construct pBL-tk-SeAP(+)ERE remained estrogen responsive. However when the tk promoter was replaced by the cytomegalovirus (cmv) promoter, the resulting plasmid (pBL-cmv-SeAP(+)ERE) was not estrogen responsive. Inhibition of ERE function was not due to an effect in trans or due to lack of estrogen receptor. It was not due to an interaction between the cmv promoter and the SeAP gene. cmv promoter function was dependent on NF-kappaB, and mutagenesis in the NF-kappaB sites reduced basal reporter expression without imparting responsiveness to estrogen. A mutation in the TATA box also failed to impart estrogen responsiveness. Modeling of DNA accessibility indicated the ERE was inserted at a site accessible to transcription factors. We conclude that the cmv promoter inhibits ERE function in cis when the two sequences are located in the same construct, and that this effect does not involve an interaction between cmv and reporter gene, NF-kappaB sites or the TATA box, or DNA inaccessibility.
Individuals with increased inflammatory response to ozone demonstrate muted signaling of immune cell trafficking pathways

EPA Science Inventory

Background Exposure to ozone activates innate immune function and causes neutrophilic (PMN) airway inflammation that in some individuals is robustly elevated. The interplay between immunoinflammatory function and genomic signaling in those with heightened inflammatory responsive...
32 CFR 300.8 - Initial determinations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... OF INFORMATION ACT PROGRAM DEFENSE LOGISTICS AGENCY FREEDOM OF INFORMATION ACT PROGRAM FOIA Request... make the determination for records within their area of functional responsibility. If a request involves records from more than one functional area, consultation will be done with all responsible IDAs...
24 CFR 582.340 - Other Federal requirements.

Code of Federal Regulations, 2011 CFR

2011-04-01

... appointed official of the recipient and who exercises or has exercised any functions or responsibilities... or gain inside information with regard to such activities, may obtain a personal or financial... has withdrawn from his or her functions or responsibilities, or the decisionmaking process with...
24 CFR 582.340 - Other Federal requirements.

Code of Federal Regulations, 2013 CFR

2013-04-01

... appointed official of the recipient and who exercises or has exercised any functions or responsibilities... or gain inside information with regard to such activities, may obtain a personal or financial... has withdrawn from his or her functions or responsibilities, or the decisionmaking process with...
24 CFR 891.400 - Responsibilities of owner.

Code of Federal Regulations, 2012 CFR

2012-04-01

... DISABILITIES PROGRAM) SUPPORTIVE HOUSING FOR THE ELDERLY AND PERSONS WITH DISABILITIES Project Management § 891... unleased units or residential spaces. (b) Management and maintenance. The Owner is responsible for all management functions. These functions include selection and admission of tenants, required reexaminations of...
24 CFR 891.400 - Responsibilities of owner.

Code of Federal Regulations, 2013 CFR

2013-04-01

... DISABILITIES PROGRAM) SUPPORTIVE HOUSING FOR THE ELDERLY AND PERSONS WITH DISABILITIES Project Management § 891... unleased units or residential spaces. (b) Management and maintenance. The Owner is responsible for all management functions. These functions include selection and admission of tenants, required reexaminations of...
Unique roles of glucagon and glucagon-like peptides: Parallels in understanding the functions of adipokinetic hormones in stress responses in insects.

PubMed

Bednářová, Andrea; Kodrík, Dalibor; Krishnan, Natraj

2013-01-01

Glucagon is conventionally regarded as a hormone, counter regulatory in function to insulin and plays a critical anti-hypoglycemic role by maintaining glucose homeostasis in both animals and humans. Glucagon performs this function by increasing hepatic glucose output to the blood by stimulating glycogenolysis and gluconeogenesis in response to starvation. Additionally it plays a homeostatic role by decreasing glycogenesis and glycolysis in tandem to try and maintain optimal glucose levels. To perform this action, it also increases energy expenditure which is contrary to what one would expect and has actions which are unique and not entirely in agreement with its role in protection from hypoglycemia. Interestingly, glucagon-like peptides (GLP-1 and GLP-2) from the major fragment of proglucagon (in non-mammalian vertebrates, as well as in mammals) may also modulate response to stress in addition to their other physiological actions. These unique modes of action occur in response to psychological, metabolic and other stress situations and mirror the role of adipokinetic hormones (AKHs) in insects which perform a similar function. The findings on the anti-stress roles of glucagon and glucagon-like peptides in mammalian and non-mammalian vertebrates may throw light on the multiple stress responsive mechanisms which operate in a concerted manner under regulation by AKH in insects thus functioning as a stress responsive hormone while also maintaining organismal homeostasis. Copyright © 2012 Elsevier Inc. All rights reserved.
Infant differential behavioral responding to discrete emotions.

PubMed

Walle, Eric A; Reschke, Peter J; Camras, Linda A; Campos, Joseph J

2017-10-01

Emotional communication regulates the behaviors of social partners. Research on individuals' responding to others' emotions typically compares responses to a single negative emotion compared with responses to a neutral or positive emotion. Furthermore, coding of such responses routinely measure surface level features of the behavior (e.g., approach vs. avoidance) rather than its underlying function (e.g., the goal of the approach or avoidant behavior). This investigation examined infants' responding to others' emotional displays across 5 discrete emotions: joy, sadness, fear, anger, and disgust. Specifically, 16-, 19-, and 24-month-old infants observed an adult communicate a discrete emotion toward a stimulus during a naturalistic interaction. Infants' responses were coded to capture the function of their behaviors (e.g., exploration, prosocial behavior, and security seeking). The results revealed a number of instances indicating that infants use different functional behaviors in response to discrete emotions. Differences in behaviors across emotions were clearest in the 24-month-old infants, though younger infants also demonstrated some differential use of behaviors in response to discrete emotions. This is the first comprehensive study to identify differences in how infants respond with goal-directed behaviors to discrete emotions. Additionally, the inclusion of a function-based coding scheme and interpersonal paradigms may be informative for future emotion research with children and adults. Possible developmental accounts for the observed behaviors and the benefits of coding techniques emphasizing the function of social behavior over their form are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Intrinsic functional connectivity of the central nucleus of the amygdala and bed nucleus of the stria terminalis.

PubMed

Gorka, Adam X; Torrisi, Salvatore; Shackman, Alexander J; Grillon, Christian; Ernst, Monique

2018-03-01

The central nucleus of the amygdala (CeA) and bed nucleus of the stria terminalis (BNST), two nuclei within the central extended amygdala, function as critical relays within the distributed neural networks that coordinate sensory, emotional, and cognitive responses to threat. These structures have overlapping anatomical projections to downstream targets that initiate defensive responses. Despite these commonalities, researchers have also proposed a functional dissociation between the CeA and BNST, with the CeA promoting responses to discrete stimuli and the BNST promoting responses to diffuse threat. Intrinsic functional connectivity (iFC) provides a means to investigate the functional architecture of the brain, unbiased by task demands. Using ultra-high field neuroimaging (7-Tesla fMRI), which provides increased spatial resolution, this study compared the iFC networks of the CeA and BNST in 27 healthy individuals. Both structures were coupled with areas of the medial prefrontal cortex, hippocampus, thalamus, and periaqueductal gray matter. Compared to the BNST, the bilateral CeA was more strongly coupled with the insula and regions that support sensory processing, including thalamus and fusiform gyrus. In contrast, the bilateral BNST was more strongly coupled with regions involved in cognitive and motivational processes, including the dorsal paracingulate gyrus, posterior cingulate cortex, and striatum. Collectively, these findings suggest that responses to sensory stimulation are preferentially coordinated by the CeA and cognitive and motivational responses are preferentially coordinated by the BNST. Published by Elsevier Inc.
Feeding behaviour of the nauplii of the marine calanoid copepod Paracartia grani Sars: Functional response, prey size spectrum, and effects of the presence of alternative prey.

PubMed

Helenius, Laura K; Saiz, Enric

2017-01-01

Laboratory feeding experiments were conducted to study the functional response and prey size spectrum of the young naupliar stages of the calanoid copepod Paracartia grani Sars. Experiments were conducted on a range of microalgal prey of varying sizes and motility patterns. Significant feeding was found in all prey of a size range of 4.5-19.8 μm, with Holling type III functional responses observed for most prey types. The highest clearance rates occurred when nauplii fed on the dinoflagellate Heterocapsa sp. and the diatom Thalassiosira weissflogii (respectively, 0.61 and 0.70 mL ind-1 d-1), suggesting an optimal prey:predator ratio of 0.09. Additional experiments were conducted to examine the effects of the presence of alternative prey (either Heterocapsa sp. or Gymnodinium litoralis) on the functional response to the haptophyte Isochrysis galbana. In the bialgal mixtures, clearance and ingestion rates of I. galbana along the range of the functional response were significantly reduced as a result of selectivity towards the larger, alternative prey. Paradoxically, relatively large prey trigger a perception response in the nauplii, but most likely such prey cannot be completely ingested and a certain degree of sloppy feeding may occur. Our results are further evidence of the complex prey-specific feeding interactions that are likely to occur in natural assemblages with several available prey types.
The effects of stress hormones on immune function may be vital for the adaptive reconfiguration of the immune system during fight-or-flight behavior.

PubMed

Adamo, Shelley A

2014-09-01

Intense, short-term stress (i.e., robust activation of the fight-or-flight response) typically produces a transient decline in resistance to disease in animals across phyla. Chemical mediators of the stress response (e.g., stress hormones) help induce this decline, suggesting that this transient immunosuppression is an evolved response. However, determining the function of stress hormones on immune function is difficult because of their complexity. Nevertheless, evidence suggests that stress hormones help maintain maximal resistance to disease during the physiological changes needed to optimize the body for intense physical activity. Work on insects demonstrates that stress hormones both shunt resources away from the immune system during fight-or-flight responses as well as reconfigure the immune system. Reconfiguring the immune system minimizes the impact of the loss of these resources and reduces the increased costs of some immune functions due to the physiological changes demanded by the fight-or-flight response. For example, during the stress response of the cricket Gryllus texensis, some molecular resources are shunted away from the immune system and toward lipid transport, resulting in a reduction in resistance to disease. However, insects' immune cells (hemocytes) have receptors for octopamine (the insect stress neurohormone). Octopamine increases many hemocyte functions, such as phagocytosis, and these changes would tend to mitigate the decline in immunity due to the loss of molecular resources. Moreover, because the stress response generates oxidative stress, some immune responses are probably more costly when activated during a stress response (e.g., those that produce reactive molecules). Some of these immune responses are depressed during stress in crickets, while others, whose costs are probably not increased during a stress response, are enhanced. Some effects of stress hormones on immune systems may be better understood as examples of reconfiguration rather than as mediating a trade-off. © The Author 2014. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.
Computer method for identification of boiler transfer functions

NASA Technical Reports Server (NTRS)

Miles, J. H.

1971-01-01

An iterative computer method is described for identifying boiler transfer functions using frequency response data. An objective penalized performance measure and a nonlinear minimization technique are used to cause the locus of points generated by a transfer function to resemble the locus of points obtained from frequency response measurements. Different transfer functions can be tried until a satisfactory empirical transfer function to the system is found. To illustrate the method, some examples and some results from a study of a set of data consisting of measurements of the inlet impedance of a single tube forced flow boiler with inserts are given.
Versatile functional roles of horizontal cells in the retinal circuit.

PubMed

Chaya, Taro; Matsumoto, Akihiro; Sugita, Yuko; Watanabe, Satoshi; Kuwahara, Ryusuke; Tachibana, Masao; Furukawa, Takahisa

2017-07-17

In the retinal circuit, environmental light signals are converted into electrical signals that can be decoded properly by the brain. At the first synapse of the visual system, information flow from photoreceptors to bipolar cells is modulated by horizontal cells (HCs), however, their functional contribution to retinal output and individual visual function is not fully understood. In the current study, we investigated functional roles for HCs in retinal ganglion cell (RGC) response properties and optokinetic responses by establishing a HC-depleted mouse line. We observed that HC depletion impairs the antagonistic center-surround receptive field formation of RGCs, supporting a previously reported HC function revealed by pharmacological approaches. In addition, we found that HC loss reduces both the ON and OFF response diversities of RGCs, impairs adjustment of the sensitivity to ambient light at the retinal output level, and alters spatial frequency tuning at an individual level. Taken together, our current study suggests multiple functional aspects of HCs crucial for visual processing.
Linear response theory for annealing of radiation damage in semiconductor devices

NASA Technical Reports Server (NTRS)

Litovchenko, Vitaly

1988-01-01

A theoretical study of the radiation/annealing response of MOS ICs is described. Although many experiments have been performed in this field, no comprehensive theory dealing with radiation/annealing response has been proposed. Many attempts have been made to apply linear response theory, but no theoretical foundation has been presented. The linear response theory outlined here is capable of describing a broad area of radiation/annealing response phenomena in MOS ICs, in particular, both simultaneous irradiation and annealing, as well as short- and long-term annealing, including the case when annealing is nearing completion. For the first time, a simple procedure is devised to determine the response function from experimental radiation/annealing data. In addition, this procedure enables us to study the effect of variable temperature and dose rate, effects which are of interest in spaceflight. In the past, the shift in threshold potential due to radiation/annealing has usually been assumed to depend on one variable: the time lapse between an impulse dose and the time of observation. While such a suggestion of uniformity in time is certainly true for a broad range of radiation annealing phenomena, it may not hold for some ranges of the variables of interest (temperature, dose rate, etc.). A response function is projected which is dependent on two variables: the time of observation and the time of the impulse dose. This dependence on two variables allows us to extend the theory to the treatment of a variable dose rate. Finally, the linear theory is generalized to the case in which the response is nonlinear with impulse dose, but is proportional to some impulse function of dose. A method to determine both the impulse and response functions is presented.
Policing the intestinal epithelial barrier: Innate immune functions of intraepithelial lymphocytes.

PubMed

Hu, Madeleine D; Jia, Luo; Edelblum, Karen L

2018-03-01

This review will explore the contribution of IELs to mucosal innate immunity and highlight the similarities in IEL functional responses to bacteria, viruses and protozoan parasite invasion. IELs rapidly respond to microbial invasion by activating host defense responses, including the production of mucus and antimicrobial peptides to prevent microbes from reaching the epithelial surface. During active infection, IELs promote epithelial cytolysis, cytokine and chemokine production to limit pathogen invasion, replication and dissemination. Commensal-induced priming of IEL effector function or continuous surveillance of the epithelium may be important contributing factors to the rapidity of response. Impaired microbial recognition, dysregulated innate immune signaling or microbial dysbiosis may limit the protective function of IELs and increase susceptibility to disease. Further understanding of the mechanisms regulating IEL surveillance and sentinel function may provide insight into the development of more effective targeted therapies designed to reinforce the mucosal barrier.
Robots in food systems: a review and assessment of potential uses.

PubMed

Adams, E A; Messersmith, A M

1986-04-01

Management personnel in foodservice, food processing, and robot industries were surveyed to evaluate potential job functions for robots in the food industry. The survey instrument listed 64 different food-related job functions that participants were asked to assess as appropriate or not appropriate for robotic implementation. Demographic data were collected from each participant to determine any positive or negative influence on job function responses. The survey responses were statistically evaluated using frequencies and the chi-square test of significance. Sixteen of the 64 job functions were identified as appropriate for robot implementation in food industries by both robot manufacturing and food managers. The study indicated, first, that food managers lack knowledge about robots and robot manufacturing managers lack knowledge about food industries. Second, robots are not currently being used to any extent in the food industry. Third, analysis of the demographic data in relation to the 16 identified job functions showed no significant differences in responses.

Gain-of-function human STAT1 mutations impair IL-17 immunity and underlie chronic mucocutaneous candidiasis.

PubMed

Liu, Luyan; Okada, Satoshi; Kong, Xiao-Fei; Kreins, Alexandra Y; Cypowyj, Sophie; Abhyankar, Avinash; Toubiana, Julie; Itan, Yuval; Audry, Magali; Nitschke, Patrick; Masson, Cécile; Toth, Beata; Flatot, Jérome; Migaud, Mélanie; Chrabieh, Maya; Kochetkov, Tatiana; Bolze, Alexandre; Borghesi, Alessandro; Toulon, Antoine; Hiller, Julia; Eyerich, Stefanie; Eyerich, Kilian; Gulácsy, Vera; Chernyshova, Ludmyla; Chernyshov, Viktor; Bondarenko, Anastasia; Grimaldo, Rosa María Cortés; Blancas-Galicia, Lizbeth; Beas, Ileana Maria Madrigal; Roesler, Joachim; Magdorf, Klaus; Engelhard, Dan; Thumerelle, Caroline; Burgel, Pierre-Régis; Hoernes, Miriam; Drexel, Barbara; Seger, Reinhard; Kusuma, Theresia; Jansson, Annette F; Sawalle-Belohradsky, Julie; Belohradsky, Bernd; Jouanguy, Emmanuelle; Bustamante, Jacinta; Bué, Mélanie; Karin, Nathan; Wildbaum, Gizi; Bodemer, Christine; Lortholary, Olivier; Fischer, Alain; Blanche, Stéphane; Al-Muhsen, Saleh; Reichenbach, Janine; Kobayashi, Masao; Rosales, Francisco Espinosa; Lozano, Carlos Torres; Kilic, Sara Sebnem; Oleastro, Matias; Etzioni, Amos; Traidl-Hoffmann, Claudia; Renner, Ellen D; Abel, Laurent; Picard, Capucine; Maródi, László; Boisson-Dupuis, Stéphanie; Puel, Anne; Casanova, Jean-Laurent

2011-08-01

Chronic mucocutaneous candidiasis disease (CMCD) may be caused by autosomal dominant (AD) IL-17F deficiency or autosomal recessive (AR) IL-17RA deficiency. Here, using whole-exome sequencing, we identified heterozygous germline mutations in STAT1 in 47 patients from 20 kindreds with AD CMCD. Previously described heterozygous STAT1 mutant alleles are loss-of-function and cause AD predisposition to mycobacterial disease caused by impaired STAT1-dependent cellular responses to IFN-γ. Other loss-of-function STAT1 alleles cause AR predisposition to intracellular bacterial and viral diseases, caused by impaired STAT1-dependent responses to IFN-α/β, IFN-γ, IFN-λ, and IL-27. In contrast, the 12 AD CMCD-inducing STAT1 mutant alleles described here are gain-of-function and increase STAT1-dependent cellular responses to these cytokines, and to cytokines that predominantly activate STAT3, such as IL-6 and IL-21. All of these mutations affect the coiled-coil domain and impair the nuclear dephosphorylation of activated STAT1, accounting for their gain-of-function and dominance. Stronger cellular responses to the STAT1-dependent IL-17 inhibitors IFN-α/β, IFN-γ, and IL-27, and stronger STAT1 activation in response to the STAT3-dependent IL-17 inducers IL-6 and IL-21, hinder the development of T cells producing IL-17A, IL-17F, and IL-22. Gain-of-function STAT1 alleles therefore cause AD CMCD by impairing IL-17 immunity.
Functional response and population dynamics for fighting predator, based on activity distribution.

PubMed

Garay, József; Varga, Zoltán; Gámez, Manuel; Cabello, Tomás

2015-03-07

The classical Holling type II functional response, describing the per capita predation as a function of prey density, was modified by Beddington and de Angelis to include interference of predators that increases with predator density and decreases the number of killed prey. In the present paper we further generalize the Beddington-de Angelis functional response, considering that all predator activities (searching and handling prey, fight and recovery) have time duration, the probabilities of predator activities depend on the encounter probabilities, and hence on the prey and predator abundance, too. Under these conditions, the aim of the study is to introduce a functional response for fighting the predator and to analyse the corresponding dynamics, when predator-predator-prey encounters also occur. From this general approach, the Holling type functional responses can also be obtained as particular cases. In terms of the activity distribution, we give biologically interpretable sufficient conditions for stable coexistence. We consider two-individual (predator-prey) and three-individual (predator-predator-prey) encounters. In the three-individual encounter model there is a relatively higher fighting rate and a lower killing rate. Using numerical simulation, we surprisingly found that when the intrinsic prey growth rate and the conversion rate are small enough, the equilibrium predator abundance is higher in the three-individual encounter case. The above means that, when the equilibrium abundance of the predator is small, coexistence appears first in the three-individual encounter model. Copyright © 2014 Elsevier Ltd. All rights reserved.
Validation study of a web-based assessment of functional recovery after radical prostatectomy.

PubMed

Vickers, Andrew J; Savage, Caroline J; Shouery, Marwan; Eastham, James A; Scardino, Peter T; Basch, Ethan M

2010-08-05

Good clinical care of prostate cancer patients after radical prostatectomy depends on careful assessment of post-operative morbidities, yet physicians do not always judge patient symptoms accurately. Logistical problems associated with using paper questionnaire limit their use in the clinic. We have implemented a web-interface ("STAR") for patient-reported outcomes after radical prostatectomy. We analyzed data on the first 9 months of clinical implementation to evaluate the validity of the STAR questionnaire to assess functional outcomes following radical prostatectomy. We assessed response rate, internal consistency within domains, and the association between survey responses and known predictors of sexual and urinary function, including age, time from surgery, nerve sparing status and co-morbidities. Of 1581 men sent an invitation to complete the instrument online, 1235 responded for a response rate of 78%. Cronbach's alpha was 0.84, 0.86 and 0.97 for bowel, urinary and sexual function respectively. All known predictors of sexual and urinary function were significantly associated with survey responses in the hypothesized direction. We have found that web-based assessment of functional recovery after radical prostatectomy is practical and feasible. The instrument demonstrated excellent psychometric properties, suggested that validity is maintained when questions are transferred from paper to electronic format and when patients give responses that they know will be seen by their doctor and added to their clinic record. As such, our system allows ready implementation of patient-reported outcomes into routine clinical practice.
Convergence in the temperature response of leaf respiration across biomes and plant functional types

PubMed Central

Heskel, Mary A.; O’Sullivan, Odhran S.; Reich, Peter B.; Tjoelker, Mark G.; Weerasinghe, Lasantha K.; Penillard, Aurore; Egerton, John J. G.; Creek, Danielle; Bloomfield, Keith J.; Xiang, Jen; Sinca, Felipe; Stangl, Zsofia R.; Martinez-de la Torre, Alberto; Griffin, Kevin L.; Huntingford, Chris; Hurry, Vaughan; Meir, Patrick; Turnbull, Matthew H.; Atkin, Owen K.

2016-01-01

Plant respiration constitutes a massive carbon flux to the atmosphere, and a major control on the evolution of the global carbon cycle. It therefore has the potential to modulate levels of climate change due to the human burning of fossil fuels. Neither current physiological nor terrestrial biosphere models adequately describe its short-term temperature response, and even minor differences in the shape of the response curve can significantly impact estimates of ecosystem carbon release and/or storage. Given this, it is critical to establish whether there are predictable patterns in the shape of the respiration–temperature response curve, and thus in the intrinsic temperature sensitivity of respiration across the globe. Analyzing measurements in a comprehensive database for 231 species spanning 7 biomes, we demonstrate that temperature-dependent increases in leaf respiration do not follow a commonly used exponential function. Instead, we find a decelerating function as leaves warm, reflecting a declining sensitivity to higher temperatures that is remarkably uniform across all biomes and plant functional types. Such convergence in the temperature sensitivity of leaf respiration suggests that there are universally applicable controls on the temperature response of plant energy metabolism, such that a single new function can predict the temperature dependence of leaf respiration for global vegetation. This simple function enables straightforward description of plant respiration in the land-surface components of coupled earth system models. Our cross-biome analyses shows significant implications for such fluxes in cold climates, generally projecting lower values compared with previous estimates. PMID:27001849
[Functional analysis of Grp and Iris, the gag and env domesticated errantivirus genes, in the Drosophila melanogaster genome].

PubMed

Makhnovskii, P A; Kuzmin, I V; Nefedova, L N; Kima, A I

2016-01-01

Drosophila melanogaster is the only invertebrate that contains endogenous retroviruses, which are called errantiviruses. Two domesticated genes, Grp and Iris, which originate from errantivirus gag and env, respectively, have been found in the D. melanogaster genome. The functions performed by the genes in Drosophila are still unclear. To identify the functions of domesticated gag and env in the D. melanogaster genome, expression of Iris and Grp was studied in strains differing by the presence or absence of the functional gypsy errantivirus. In addition, the expression levels were measured after injection of gram-positive and gram-negative bacteria, which activate different immune response pathways, and exposure to various abiotic stress factors. The presence of functional D. melanogaster retrovirus gypsy was found to increase the Grp expression level in somatic tissues of the carcass, while exerting no effect on the Iris expression level. Activation of the immune response in D. melanogaster by bacteria Bacillus cereus increased the Grp expression level and did not affect Iris expression. As for the effects of abiotic stress factors (oxidative stress, starvation, and heat and cold stress), the Grp expression level increased in response to starvation in D. melanogaster females, and the Iris expression level was downregulated in heat shock and oxidative stress. Based on the findings, Grp was assumed to play a direct role in the immune response in D. melanogaster; Iris is not involved in immune responses, but and apparently performs a cell function that is inhibited in stress.
Validation study of a web-based assessment of functional recovery after radical prostatectomy

PubMed Central

2010-01-01

Background Good clinical care of prostate cancer patients after radical prostatectomy depends on careful assessment of post-operative morbidities, yet physicians do not always judge patient symptoms accurately. Logistical problems associated with using paper questionnaire limit their use in the clinic. We have implemented a web-interface ("STAR") for patient-reported outcomes after radical prostatectomy. Methods We analyzed data on the first 9 months of clinical implementation to evaluate the validity of the STAR questionnaire to assess functional outcomes following radical prostatectomy. We assessed response rate, internal consistency within domains, and the association between survey responses and known predictors of sexual and urinary function, including age, time from surgery, nerve sparing status and co-morbidities. Results Of 1581 men sent an invitation to complete the instrument online, 1235 responded for a response rate of 78%. Cronbach's alpha was 0.84, 0.86 and 0.97 for bowel, urinary and sexual function respectively. All known predictors of sexual and urinary function were significantly associated with survey responses in the hypothesized direction. Conclusions We have found that web-based assessment of functional recovery after radical prostatectomy is practical and feasible. The instrument demonstrated excellent psychometric properties, suggested that validity is maintained when questions are transferred from paper to electronic format and when patients give responses that they know will be seen by their doctor and added to their clinic record. As such, our system allows ready implementation of patient-reported outcomes into routine clinical practice. PMID:20687938
Convergence in the temperature response of leaf respiration across biomes and plant functional types.

PubMed

Heskel, Mary A; O'Sullivan, Odhran S; Reich, Peter B; Tjoelker, Mark G; Weerasinghe, Lasantha K; Penillard, Aurore; Egerton, John J G; Creek, Danielle; Bloomfield, Keith J; Xiang, Jen; Sinca, Felipe; Stangl, Zsofia R; Martinez-de la Torre, Alberto; Griffin, Kevin L; Huntingford, Chris; Hurry, Vaughan; Meir, Patrick; Turnbull, Matthew H; Atkin, Owen K

2016-04-05

Plant respiration constitutes a massive carbon flux to the atmosphere, and a major control on the evolution of the global carbon cycle. It therefore has the potential to modulate levels of climate change due to the human burning of fossil fuels. Neither current physiological nor terrestrial biosphere models adequately describe its short-term temperature response, and even minor differences in the shape of the response curve can significantly impact estimates of ecosystem carbon release and/or storage. Given this, it is critical to establish whether there are predictable patterns in the shape of the respiration-temperature response curve, and thus in the intrinsic temperature sensitivity of respiration across the globe. Analyzing measurements in a comprehensive database for 231 species spanning 7 biomes, we demonstrate that temperature-dependent increases in leaf respiration do not follow a commonly used exponential function. Instead, we find a decelerating function as leaves warm, reflecting a declining sensitivity to higher temperatures that is remarkably uniform across all biomes and plant functional types. Such convergence in the temperature sensitivity of leaf respiration suggests that there are universally applicable controls on the temperature response of plant energy metabolism, such that a single new function can predict the temperature dependence of leaf respiration for global vegetation. This simple function enables straightforward description of plant respiration in the land-surface components of coupled earth system models. Our cross-biome analyses shows significant implications for such fluxes in cold climates, generally projecting lower values compared with previous estimates.
Child pain catastrophizing mediates the relationship between parent responses to pain and disability in youth with functional abdominal pain

PubMed Central

Cunningham, Natoshia Raishevich; Lynch-Jordan, Anne; Barnett, Kimberly; Peugh, James; Sil, Soumitri; Goldschneider, Kenneth; Kashikar-Zuck, Susmita

2014-01-01

Objectives Functional abdominal pain (FAP) in youth is associated with substantial impairment in functioning and prior research has shown that overprotective parent responses can heighten impairment. Little is known about how a range of parental behaviors in response to their child’s pain (overprotection, minimizing and/or encouragement) interact with child coping characteristics (e.g., catastrophizing) to influence functioning in youth with FAP. In this study, it was hypothesized that the relationship between parenting factors and child disability would be mediated by children’s level of maladaptive coping (i.e., pain catastrophizing). Methods Seventy-five patients with FAP presenting to a pediatric pain clinic and their caregivers participated. Youth completed measures of pain intensity (Numeric Rating Scale), pain catastrophizing (Pain Catastrophizing Scale), and disability (Functional Disability Inventory). Caregivers completed measures of parent pain catastrophizing (Pain Catastrophizing Scale), and parent responses to child pain behaviors (Adult Responses to Child Symptoms: protection, minimizing, and encouragement/monitoring subscales). Results Increased functional disability was significantly related to higher child pain intensity, increased child and parent pain catastrophizing, and higher levels of encouragement/monitoring and protection. Parent minimization was not related to disability. Child pain catastrophizing fully mediated the relationship between parent encouragement/monitoring and disability and partially mediated the relationship between parent protectiveness and disability. Conclusions The impact of parenting behaviors in response to FAP on child disability is determined in part by the child’s coping style. Findings highlight a more nuanced understanding of the parent-child interaction in determining pain-related disability levels, which should be taken into consideration in assessing and treating youth with FAP. PMID:25121521
Genomic, genetic and functional dissection of bitter taste responses to artificial sweeteners.

PubMed

Roudnitzky, Natacha; Bufe, Bernd; Thalmann, Sophie; Kuhn, Christina; Gunn, Howard C; Xing, Chao; Crider, Bill P; Behrens, Maik; Meyerhof, Wolfgang; Wooding, Stephen P

2011-09-01

Bitter taste perception is initiated by TAS2R receptors, which respond to agonists by triggering depolarization of taste bud cells. Mutations in TAS2Rs are known to affect taste phenotypes by altering receptor function. Evidence that TAS2Rs overlap in ligand specificity suggests that they may also contribute joint effects. To explore this aspect of gustation, we examined bitter perception of saccharin and acesulfame K, widely used artificial sweeteners with aversive aftertastes. Both substances are agonists of TAS2R31 and -43, which belong to a five-member subfamily (TAS2R30-46) responsive to a diverse constellation of compounds. We analyzed sequence variation and linkage structure in the ∼140 kb genomic region encoding TAS2R30-46, taste responses to the two sweeteners in subjects, and functional characteristics of receptor alleles. Whole-gene sequences from TAS2R30-46 in 60 Caucasian subjects revealed extensive diversity including 34 missense mutations, two nonsense mutations and high-frequency copy-number variants. Thirty markers, including non-synonymous variants in all five genes, were associated (P< 0.001) with responses to saccharin and acesulfame K. However, linkage disequilibrium (LD) in the region was high (D', r(2) > 0.95). Haplotype analyses revealed that most associations were spurious, arising from LD with variants in TAS2R31. In vitro assays confirmed the functional importance of four TAS2R31 mutations, which had independent effects on receptor response. The existence of high LD spanning functionally distinct TAS2R loci predicts that bitter taste responses to many compounds will be strongly correlated even when they are mediated by different genes. Integrative approaches combining phenotypic, genetic and functional analysis will be essential in dissecting these complex relationships.
Intra- and interspecific responses to Rafinesque’s big-eared bat (Corynorhinus rafinesquii) social calls

Treesearch

S. Loeb; E. Britzke

2010-01-01

Bats respond to the calls of conspecifics as well as to calls of other species; however, few studies have attempted to quantify these responses or understand the functions of these calls. We tested the response of Rafinesqueâs big-eared bats (Corynorhinus rafinesquii) to social calls as a possible method to increase capture success and to understand the function of...
Level-tolerant duration selectivity in the auditory cortex of the velvety free-tailed bat Molossus molossus.

PubMed

Macías, Silvio; Hernández-Abad, Annette; Hechavarría, Julio C; Kössl, Manfred; Mora, Emanuel C

2015-05-01

It has been reported previously that in the inferior colliculus of the bat Molossus molossus, neuronal duration tuning is ambiguous because the tuning type of the neurons dramatically changes with the sound level. In the present study, duration tuning was examined in the auditory cortex of M. molossus to describe if it is as ambiguous as the collicular tuning. From a population of 174 cortical 104 (60 %) neurons did not show duration selectivity (all-pass). Around 5 % (9 units) responded preferentially to stimuli having longer durations showing long-pass duration response functions, 35 (20 %) responded to a narrow range of stimulus durations showing band-pass duration response functions, 24 (14 %) responded most strongly to short stimulus durations showing short-pass duration response functions and two neurons (1 %) responded best to two different stimulus durations showing a two-peaked duration-response function. The majority of neurons showing short- (16 out of 24) and band-pass (24 out 35) selectivity displayed "O-shaped" duration response areas. In contrast to the inferior colliculus, duration tuning in the auditory cortex of M. molossus appears level tolerant. That is, the type of duration selectivity and the stimulus duration eliciting the maximum response were unaffected by changing sound level.
Peripheral functional organisation of vagally evoked gastric motor responses in the ferret.

PubMed Central

Andrews, P L; Lawes, I N; Bower, A J

1980-01-01

The aims of the present study were to determine the relative amplitudes of intragastric motor responses evoked by different vagal branches and to establish whether the effects of acute or chronic vagotomy could be predicted from these data. Intragastric pressure responses to electrical stimulation of the vagus were measured in urethane-anaesthetised ferrets and acute or chronic vagotomies were performed. The results show that the left and right cervical vagi were equipotential and fully overlaped each other. Their contributions to the dorsal trunk were equipotential and fully overlapping and so were their contributions to the ventral trunk. The dorsal trunk was more effective than the ventral trunk and there was total functional overlap between these two trunks. Vagal evoked gastric motor responses of the ferret are apparently organised in a different way from vagally induced acid secretion or hormone release in the cat. Acute removal of a trunk led to a reduction in evoked responses that was not linear function of the effect of stimulation of that trunk. In contrast, chronic removal caused a relative increase in evoked responses that ws inversely related to the decrease caused by acute removal. The implications of total functional overlap and neuromuscular reorganisation after chronic vagotomy are discussed. PMID:7439800
Surgical inflammatory stress: the embryo takes hold of the reins again

PubMed Central

2013-01-01

The surgical inflammatory response can be a type of high-grade acute stress response associated with an increasingly complex trophic functional system for using oxygen. This systemic neuro-immune-endocrine response seems to induce the re-expression of 2 extraembryonic-like functional axes, i.e. coelomic-amniotic and trophoblastic-yolk-sac-related, within injured tissues and organs, thus favoring their re-development. Accordingly, through the up-regulation of two systemic inflammatory phenotypes, i.e. neurogenic and immune-related, a gestational-like response using embryonic functions would be induced in the patient’s injured tissues and organs, which would therefore result in their repair. Here we establish a comparison between the pathophysiological mechanisms that are produced during the inflammatory response and the physiological mechanisms that are expressed during early embryonic development. In this way, surgical inflammation could be a high-grade stress response whose pathophysiological mechanisms would be based on the recapitulation of ontogenic and phylogenetic-related functions. Thus, the ultimate objective of surgical inflammation, as a gestational process, is creating new tissues/organs for repairing the injured ones. Since surgical inflammation and early embryonic development share common production mechanisms, the factors that hamper the wound healing reaction in surgical patients could be similar to those that impair the gestational process. PMID:23374964
Amplitude, Latency, and Peak Velocity in Accommodation and Disaccommodation Dynamics

PubMed Central

Papadatou, Eleni; Ferrer-Blasco, Teresa; Montés-Micó, Robert

2017-01-01

The aim of this work was to ascertain whether there are differences in amplitude, latency, and peak velocity of accommodation and disaccommodation responses when different analysis strategies are used to compute them, such as fitting different functions to the responses or for smoothing them prior to computing the parameters. Accommodation and disaccommodation responses from four subjects to pulse changes in demand were recorded by means of aberrometry. Three different strategies were followed to analyze such responses: fitting an exponential function to the experimental data; fitting a Boltzmann sigmoid function to the data; and smoothing the data. Amplitude, latency, and peak velocity of the responses were extracted. Significant differences were found between the peak velocity in accommodation computed by fitting an exponential function and smoothing the experimental data (mean difference 2.36 D/s). Regarding disaccommodation, significant differences were found between latency and peak velocity, calculated with the two same strategies (mean difference of 0.15 s and −3.56 D/s, resp.). The strategy used to analyze accommodation and disaccommodation responses seems to affect the parameters that describe accommodation and disaccommodation dynamics. These results highlight the importance of choosing the most adequate analysis strategy in each individual to obtain the parameters that characterize accommodation and disaccommodation dynamics. PMID:29226128
Linear-response time-dependent density-functional theory with pairing fields.

PubMed

Peng, Degao; van Aggelen, Helen; Yang, Yang; Yang, Weitao

2014-05-14

Recent development in particle-particle random phase approximation (pp-RPA) broadens the perspective on ground state correlation energies [H. van Aggelen, Y. Yang, and W. Yang, Phys. Rev. A 88, 030501 (2013), Y. Yang, H. van Aggelen, S. N. Steinmann, D. Peng, and W. Yang, J. Chem. Phys. 139, 174110 (2013); D. Peng, S. N. Steinmann, H. van Aggelen, and W. Yang, J. Chem. Phys. 139, 104112 (2013)] and N ± 2 excitation energies [Y. Yang, H. van Aggelen, and W. Yang, J. Chem. Phys. 139, 224105 (2013)]. So far Hartree-Fock and approximated density-functional orbitals have been utilized to evaluate the pp-RPA equation. In this paper, to further explore the fundamentals and the potential use of pairing matrix dependent functionals, we present the linear-response time-dependent density-functional theory with pairing fields with both adiabatic and frequency-dependent kernels. This theory is related to the density-functional theory and time-dependent density-functional theory for superconductors, but is applied to normal non-superconducting systems for our purpose. Due to the lack of the proof of the one-to-one mapping between the pairing matrix and the pairing field for time-dependent systems, the linear-response theory is established based on the representability assumption of the pairing matrix. The linear response theory justifies the use of approximated density-functionals in the pp-RPA equation. This work sets the fundamentals for future density-functional development to enhance the description of ground state correlation energies and N ± 2 excitation energies.
Influenza A virus-dependent remodeling of pulmonary clock function in a mouse model of COPD

PubMed Central

Sundar, Isaac K.; Ahmad, Tanveer; Yao, Hongwei; Hwang, Jae-woong; Gerloff, Janice; Lawrence, B. Paige; Sellix, Michael T.; Rahman, Irfan

2015-01-01

Daily oscillations of pulmonary function depend on the rhythmic activity of the circadian timing system. Environmental tobacco/cigarette smoke (CS) disrupts circadian clock leading to enhanced inflammatory responses. Infection with influenza A virus (IAV) increases hospitalization rates and death in susceptible individuals, including patients with Chronic Obstructive Pulmonary Disease (COPD). We hypothesized that molecular clock disruption is enhanced by IAV infection, altering cellular and lung function, leading to severity in airway disease phenotypes. C57BL/6J mice exposed to chronic CS, BMAL1 knockout (KO) mice and wild-type littermates were infected with IAV. Following infection, we measured diurnal rhythms of clock gene expression in the lung, locomotor activity, pulmonary function, inflammatory, pro-fibrotic and emphysematous responses. Chronic CS exposure combined with IAV infection altered the timing of clock gene expression and reduced locomotor activity in parallel with increased lung inflammation, disrupted rhythms of pulmonary function, and emphysema. BMAL1 KO mice infected with IAV showed pronounced detriments in behavior and survival, and increased lung inflammatory and pro-fibrotic responses. This suggests that remodeling of lung clock function following IAV infection alters clock-dependent gene expression and normal rhythms of lung function, enhanced emphysematous and injurious responses. This may have implications for the pathobiology of respiratory virus-induced airway disease severity and exacerbations. PMID:25923474
Quadratic response functions in the relativistic four-component Kohn-Sham approximation

NASA Astrophysics Data System (ADS)

Henriksson, Johan; Saue, Trond; Norman, Patrick

2008-01-01

A formulation and implementation of the quadratic response function in the adiabatic four-component Kohn-Sham approximation is presented. The noninteracting reference state is time-reversal symmetric and formed from Kramers pair spinors, and the energy density is gradient corrected. Example calculations are presented for the optical properties of disubstituted halobenzenes in their meta and ortho conformations. It is demonstrated that correlation and relativistic effects are not additive, and it is shown that relativity alone reduces the μβ¯-response signal by 62% and 75% for meta- and ortho-bromobenzene, respectively, and enhances the same response by 17% and 21% for meta- and ortho-iodobenzene, respectively. Of the employed functionals, CAM-B3LYP shows the best performance and gives hyperpolarizabilities β distinctly different from B3LYP.
Modelling a stochastic HIV model with logistic target cell growth and nonlinear immune response function

NASA Astrophysics Data System (ADS)

Wang, Yan; Jiang, Daqing; Alsaedi, Ahmed; Hayat, Tasawar

2018-07-01

A stochastic HIV viral model with both logistic target cell growth and nonlinear immune response function is formulated to investigate the effect of white noise on each population. The existence of the global solution is verified. By employing a novel combination of Lyapunov functions, we obtain the existence of the unique stationary distribution for small white noises. We also derive the extinction of the virus for large white noises. Numerical simulations are performed to highlight the effect of white noises on model dynamic behaviour under the realistic parameters. It is found that the small intensities of white noises can keep the irregular blips of HIV virus and CTL immune response, while the larger ones force the virus infection and immune response to lose efficacy.
Shear mode ER transfer function for robotic applications

NASA Astrophysics Data System (ADS)

Tan, K. P.; Stanway, R.; Bullough, W. A.

2005-06-01

Electro-rheological (ER) fluids are becoming popular in modern industrial applications. The advantage of employing ER devices is due to the ease of energizing the ER fluids at fast speeds of response. One innovation in ER applications could be in the positioning control of the robotic arm using an ER clutch. In order to actuate the manipulator, the ER output torque response is required. However, the behaviour of this ER torque response at different input conditions is not clearly understood. Therefore, in this paper, a sample study of the ER output torque is conducted. The ER output torque responses at different input parameters are studied carefully for the establishment of an appropriate ER transfer function in shear mode. This transfer function will serve as an important feature in future ER-actuated robot arm's control process.
Self-regulating chemo-mechano-chemical systems

DOEpatents

Aizenberg, Joanna; He, Ximin; Aizenberg, Michael

2017-05-16

A chemo-mechano-chemical (C.sub.1-M-C.sub.2) system includes a base supporting an actuatable structure, said structure comprising a functionalized portion and being embedded in an environmentally responsive gel capable of volume change in response to an environmental stimulus; a first fluid layer disposed over the base and in contact with the actuatable structure, said first fluid layer comprising the environmentally responsive gel; and a second fluid layer in contact with the actuatable structure, wherein the layers are positioned such that the functionalized portion is in contact with the second layer in a first relaxed state and in contact with the first layer in a second actuated state and wherein the functionalized portion interacts with at least one of the layers to provide a chemical or physical response.

The Hepatic Response to Thermal Injury: Is the Liver Important for Postburn Outcomes?

PubMed Central

Jeschke, Marc G

2009-01-01

Thermal injury produces a profound hypermetabolic and hypercatabolic stress response characterized by increased endogenous glucose production via gluconeogenesis and glycogenolysis, lipolysis, and proteolysis. The liver is the central body organ involved in these metabolic responses. It is suggested that the liver, with its metabolic, inflammatory, immune, and acute phase functions, plays a pivotal role in patient survival and recovery by modulating multiple pathways following thermal injury. Studies have evaluated the role and function of the liver during the postburn response and showed that liver integrity and function are essential for survival, and that hepatic acute phase proteins are strong predictors for postburn survival. This review discusses these studies and delineates the pivotal role of the liver in patients following severe thermal injury. PMID:19603107
Laser-based irradiation apparatus and method to measure the functional dose-rate response of semiconductor devices

DOEpatents

Horn, Kevin M [Albuquerque, NM

2008-05-20

A broad-beam laser irradiation apparatus can measure the parametric or functional response of a semiconductor device to exposure to dose-rate equivalent infrared laser light. Comparisons of dose-rate response from before, during, and after accelerated aging of a device, or from periodic sampling of devices from fielded operational systems can determine if aging has affected the device's overall functionality. The dependence of these changes on equivalent dose-rate pulse intensity and/or duration can be measured with the apparatus. The synchronized introduction of external electrical transients into the device under test can be used to simulate the electrical effects of the surrounding circuitry's response to a radiation exposure while exposing the device to dose-rate equivalent infrared laser light.
Different Signal Enhancement Pathways of Attention and Consciousness Underlie Perception in Humans.

PubMed

van Boxtel, Jeroen J A

2017-06-14

It is not yet known whether attention and consciousness operate through similar or largely different mechanisms. Visual processing mechanisms are routinely characterized by measuring contrast response functions (CRFs). In this report, behavioral CRFs were obtained in humans (both males and females) by measuring afterimage durations over the entire range of inducer stimulus contrasts to reveal visual mechanisms behind attention and consciousness. Deviations relative to the standard CRF, i.e., gain functions, describe the strength of signal enhancement, which were assessed for both changes due to attentional task and conscious perception. It was found that attention displayed a response-gain function, whereas consciousness displayed a contrast-gain function. Through model comparisons, which only included contrast-gain modulations, both contrast-gain and response-gain effects can be explained with a two-level normalization model, in which consciousness affects only the first level and attention affects only the second level. These results demonstrate that attention and consciousness can effectively show different gain functions because they operate through different signal enhancement mechanisms. SIGNIFICANCE STATEMENT The relationship between attention and consciousness is still debated. Mapping contrast response functions (CRFs) has allowed (neuro)scientists to gain important insights into the mechanistic underpinnings of visual processing. Here, the influence of both attention and consciousness on these functions were measured and they displayed a strong dissociation. First, attention lowered CRFs, whereas consciousness raised them. Second, attention manifests itself as a response-gain function, whereas consciousness manifests itself as a contrast-gain function. Extensive model comparisons show that these results are best explained in a two-level normalization model in which consciousness affects only the first level, whereas attention affects only the second level. These findings show dissociations between both the computational mechanisms behind attention and consciousness and the perceptual consequences that they induce. Copyright © 2017 the authors 0270-6474/17/375912-11$15.00/0.
Impact of Sofosbuvir-Based Regimens for the Treatment of Hepatitis C After Liver Transplant on Renal Function: Results of a Canadian National Retrospective Study.

PubMed

Faisal, Nabiha; Bilodeau, Marc; Aljudaibi, Bandar; Hirch, Geri; Yoshida, Eric M; Hussaini, Trana; Ghali, Maged P; Congly, Stephen E; Ma, Mang M; Lilly, Leslie B

2018-04-04

We assessed the impact of sofosbuvir-based regimens on renal function in liver transplant recipients with recurrent hepatitis C virus and the role of renal function on the efficacy and safety of these regimens. In an expanded pan-Canadian cohort, 180 liver transplant recipients were treated with sofosbuvir-based regimens for hepatitis C virus recurrence from January 2014 to May 2015. Mean age was 58 ± 6.85 years, and 50% had F3/4 fibrosis. Patients were stratified into 4 groups based on baseline estimated glomerular filtration rate (calculated by the Modification of Diet in Renal Disease formula): < 30, 30 to 45, 46 to 60, and > 60 mL/min/173 m2. The primary outcome was posttreatment changes in renal function from baseline. Secondary outcomes included sustained virologic response at 12 weeks posttreatment and anemia-related and serious adverse events. Posttreatment renal function was improved in most patients (58%). Renal function declined in 22% of patients, which was more marked in those with estimated glomerular filtration rate < 30 mL/min/173 m2, advanced cirrhosis (P = .05), and aggressive hepatitis C virus/fibrosing cholestatic hepatitis (P < .05). High rates (80%-88%) of sustained virologic response at 12 weeks posttreatment were seen across all renal function strata. Cirrhotic patients with glomerular filtration rates < 30 mL/min/173 m2 had sustained virologic response rates at 12 weeks posttreatment comparable to the overall patient group. Rates of anemia-related adverse events and transfusion requirements increased across decreasing estimated glomerular filtration rate groups, with notably more occurrences with ribavirin-based regimens. Sofosbuvir-based regimens improved overall renal function in liver transplant recipients, with sustained virologic response, suggesting an association of subclinical hepatitis C virus-related renal disease. Sustained virologic response rates at 12 weeks posttreatment (80%-88%) were comparable regardless of baseline renal function but lower in cirrhosis.
Unfolded protein response (UPR) signaling regulates arsenic trioxide-mediated macrophage innate immune function disruption

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

Srivastava, Ritesh K.; Li, Changzhao; Chaudhary, Sandeep C.

Arsenic exposure is known to disrupt innate immune functions in humans and in experimental animals. In this study, we provide a mechanism by which arsenic trioxide (ATO) disrupts macrophage functions. ATO treatment of murine macrophage cells diminished internalization of FITC-labeled latex beads, impaired clearance of phagocytosed fluorescent bacteria and reduced secretion of pro-inflammatory cytokines. These impairments in macrophage functions are associated with ATO-induced unfolded protein response (UPR) signaling pathway characterized by the enhancement in proteins such as GRP78, p-PERK, p-eIF2α, ATF4 and CHOP. The expression of these proteins is altered both at transcriptional and translational levels. Pretreatment with chemical chaperon,more » 4-phenylbutyric acid (PBA) attenuated the ATO-induced activation in UPR signaling and afforded protection against ATO-induced disruption of macrophage functions. This treatment also reduced ATO-mediated reactive oxygen species (ROS) generation. Interestingly, treatment with antioxidant N-acetylcysteine (NAC) prior to ATO exposure, not only reduced ROS production and UPR signaling but also improved macrophage functions. These data demonstrate that UPR signaling and ROS generation are interdependent and are involved in the arsenic-induced pathobiology of macrophage. These data also provide a novel strategy to block the ATO-dependent impairment in innate immune responses. - Highlights: • Inorganic arsenic to humans and experimental animals disrupt innate immune responses. • The mechanism underlying arsenic impaired macrophage functions involves UPR signaling. • Chemical chaperon attenuates arsenic-mediated macrophage function impairment. • Antioxidant, NAC blocks impairment in arsenic-treated macrophage functions.« less
Enhanced Response Time of Electrowetting Lenses with Shaped Input Voltage Functions.

PubMed

Supekar, Omkar D; Zohrabi, Mo; Gopinath, Juliet T; Bright, Victor M

2017-05-16

Adaptive optical lenses based on the electrowetting principle are being rapidly implemented in many applications, such as microscopy, remote sensing, displays, and optical communication. To characterize the response of these electrowetting lenses, the dependence upon direct current (DC) driving voltage functions was investigated in a low-viscosity liquid system. Cylindrical lenses with inner diameters of 2.45 and 3.95 mm were used to characterize the dynamic behavior of the liquids under DC voltage electrowetting actuation. With the increase of the rise time of the input exponential driving voltage, the originally underdamped system response can be damped, enabling a smooth response from the lens. We experimentally determined the optimal rise times for the fastest response from the lenses. We have also performed numerical simulations of the lens actuation with input exponential driving voltage to understand the variation in the dynamics of the liquid-liquid interface with various input rise times. We further enhanced the response time of the devices by shaping the input voltage function with multiple exponential rise times. For the 3.95 mm inner diameter lens, we achieved a response time improvement of 29% when compared to the fastest response obtained using single-exponential driving voltage. The technique shows great promise for applications that require fast response times.
32 CFR 344.5 - Relationships.

Code of Federal Regulations, 2011 CFR

2011-07-01

... CHARTERS ASSISTANT SECRETARY OF DEFENSE FOR RESERVE AFFAIRS (ASD(RA)) § 344.5 Relationships. (a) In the performance of assigned functions and responsibilities, the ASD(RA) shall serve under the authority, direction... ASD(RA) on all matters related to the responsibilities and functions cited in § 344.4. ...
A Scale for Assessing Family Dysfunction-Function

ERIC Educational Resources Information Center

Genthner, Robert W.; Veltkamp, Lane J.

1977-01-01

This paper assumes that the level of personal responsibility of family members for the performance of family tasks and family identity influences the level of function or dysfunction in the family. The more behavior is dysfunctional, the greater the denial of responsibility of family members. (Author)
Altered neural activation during prepotent response inhibition in breast cancer survivors treated with chemotherapy: an fMRI study.

PubMed

Kam, Julia W Y; Boyd, Lara A; Hsu, Chun L; Liu-Ambrose, Teresa; Handy, Todd C; Lim, Howard J; Hayden, Sherri; Campbell, Kristin L

2016-09-01

While impairments in executive functions have been reported in breast cancer survivors (BCS) who have undergone adjuvant chemotherapy, only a limited number of functional neuroimaging studies have associated alterations in cerebral activity with executive functions deficits in BCS. Using fMRI, the current study assessed the neural basis underlying a specific facet of executive function, namely prepotent response inhibition. 12 BCS who self-reported cognitive problems up to 3 years following cancer treatment and 12 female healthy comparisons (HC) performed the Stroop task. We compared their neural activation between the incongruent and neutral experimental conditions. Relative to the HC group, BCS showed lower blood-oxygen level dependent signal in several frontal regions, including the anterior cingulate cortex, a region critical for response inhibition. Our data indicates reduced neural activation in BCS during a prepotent response inhibition task, providing support for the prevailing notion of neural alterations observed in BCS treated with chemotherapy.
LANDSAT-D investigations in snow hydrology

NASA Technical Reports Server (NTRS)

Dozier, J. (Principal Investigator)

1982-01-01

Snow reflectance in all 6 TM reflective bands, i.e., 1, 2, 3, 4, 5, and 7 was simulated using a delta-Eddington model. Snow reflectance in bands 4, 5, and 7 appear sensitive to grain size. It appears that the TM filters resemble a ""square-wave'' closely enough that a square-wave can be assumed in calculations. Integrated band reflectance over the actual response functions was calculated using sensor data supplied by Santa Barbara Research Center. Differences between integrating over the actual response functions and the equivalent square wave were negligible. Tables are given which show (1) sensor saturation radiance as a percentage of the solar constant, integrated through the band response function; (2) comparisons of integrations through the sensor response function with integrations over the equivalent square wave; and (3) calculations of integrated reflectance for snow over all reflective TM bands, and water and ice clouds with thickness of 1 mm water equivalent over TM bands 5 and 7. These calculations look encouraging for snow/cloud discrimination with TM bands 5 and 7.
From Whole-Brain Data to Functional Circuit Models: The Zebrafish Optomotor Response.

PubMed

Naumann, Eva A; Fitzgerald, James E; Dunn, Timothy W; Rihel, Jason; Sompolinsky, Haim; Engert, Florian

2016-11-03

Detailed descriptions of brain-scale sensorimotor circuits underlying vertebrate behavior remain elusive. Recent advances in zebrafish neuroscience offer new opportunities to dissect such circuits via whole-brain imaging, behavioral analysis, functional perturbations, and network modeling. Here, we harness these tools to generate a brain-scale circuit model of the optomotor response, an orienting behavior evoked by visual motion. We show that such motion is processed by diverse neural response types distributed across multiple brain regions. To transform sensory input into action, these regions sequentially integrate eye- and direction-specific sensory streams, refine representations via interhemispheric inhibition, and demix locomotor instructions to independently drive turning and forward swimming. While experiments revealed many neural response types throughout the brain, modeling identified the dimensions of functional connectivity most critical for the behavior. We thus reveal how distributed neurons collaborate to generate behavior and illustrate a paradigm for distilling functional circuit models from whole-brain data. Copyright © 2016 Elsevier Inc. All rights reserved.
Parent Prediction of Child Mood and Emotional Resilience: The Role of Parental Responsiveness and Psychological Control

PubMed Central

Boughton, Kristy L.; Lumley, Margaret N.

2011-01-01

Research consistently shows low to moderate agreement between parent and child reports of child mood, suggesting that parents are not always the best predictors of child emotional functioning. This study examines parental responsiveness and psychological control for improving prediction of early adolescent mood and emotional resilience beyond parent report of child emotional functioning. Participants were 268 early adolescents administered measures of depression symptoms, emotional resilience, and perceptions of parenting. Parents of participating youth completed measures of youth emotional functioning. Parental responsiveness and psychological control each emerged as family variables that may be of value for predicting child emotional functioning beyond parent reports. Specifically, responsiveness explained significant variance in child depression and resilience after accounting for parent reports, while parental psychological control increased prediction of child mood alone. Results generally suggest that parenting behaviours may be an important consideration when children and parents provide discrepant reports of child emotional well-being. Conceptual and clinical implications of these results are discussed. PMID:22110912
Assessment of Rod, Cone, and Intrinsically Photosensitive Retinal Ganglion Cell Contributions to the Canine Chromatic Pupillary Response.

PubMed

Yeh, Connie Y; Koehl, Kristin L; Harman, Christine D; Iwabe, Simone; Guzman, José M; Petersen-Jones, Simon M; Kardon, Randy H; Komáromy, András M

2017-01-01

The purpose of this study was to evaluate a chromatic pupillometry protocol for specific functional assessment of rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs) in dogs. Chromatic pupillometry was tested and compared in 37 dogs in different stages of primary loss of rod, cone, and combined rod/cone and optic nerve function, and in 5 wild-type (WT) dogs. Eyes were stimulated with 1-s flashes of dim (1 cd/m2) and bright (400 cd/m2) blue light (for scotopic conditions) or bright red (400 cd/m2) light with 25-cd/m2 blue background (for photopic conditions). Canine retinal melanopsin/Opn4 was cloned, and its expression was evaluated using real-time quantitative reverse transcription-PCR and immunohistochemistry. Mean ± SD percentage of pupil constriction amplitudes induced by scotopic dim blue (scDB), scotopic bright blue (scBB), and photopic bright red (phBR) lights in WT dogs were 21.3% ± 10.6%, 50.0% ± 17.5%, and 19.4% ± 7.4%, respectively. Melanopsin-mediated responses to scBB persisted for several minutes (7.7 ± 4.6 min) after stimulus offset. In dogs with inherited retinal degeneration, loss of rod function resulted in absent scDB responses, followed by decreased phBR responses with disease progression and loss of cone function. Primary loss of cone function abolished phBR responses but preserved those responses to blue light (scDB and scBB). Although melanopsin/Opn4 expression was diminished with retinal degeneration, melanopsin-expressing ipRGCs were identified for the first time in both WT and degenerated canine retinas. Pupil responses elicited by light stimuli of different colors and intensities allowed differential functional assessment of canine rods, cones, and ipRGCs. Chromatic pupillometry offers an effective tool for diagnosing retinal and optic nerve diseases.
Clinical responsiveness of self-report functional assessment measures for children with juvenile idiopathic arthritis undergoing intraarticular corticosteroid injections.

PubMed

Brown, G Ted; Wright, F Virginia; Lang, Bianca A; Birdi, Nina; Oen, Kim; Stephens, Derek; McComas, Joan; Feldman, Brian M

2005-12-15

The Childhood Health Assessment Questionnaire (CHAQ), Juvenile Arthritis Functional Assessment Report (JAFAR), and Juvenile Arthritis Functional Status Index (JASI) are widely used functional measures for juvenile idiopathic arthritis (JIA) that differ in content, format, and completion time. We compared the responsiveness and child-parent agreement of the JAFAR, CHAQ, and JASI in a prospective, multicenter study. Children and adolescents from 5 rheumatology centers were enrolled. Subjects were about to undergo therapy (intraarticular corticosteroid injections [IAS] and methotrexate or hip surgery (MTX/hip]) expected to produce a functional improvement. All subjects were studied before the intervention and at 6 weeks and 6 months posttreatment. At each study visit, the 3 measures were administered in randomized, balanced order to both parents and children. A total of 92 subjects (mean age 12.8 years) were enrolled in the study, 74 of which were in the IAS group. The responsiveness of all 3 measures was moderate to strong. The standardized response mean at 6 weeks for the IAS group on the JAFAR, CHAQ, and JASI was 0.41 (95% confidence interval [95% CI] 0.18, 0.64), 0.70 (95% CI 0.47, 0.93), and 0.36 (95% CI 0.13, 0.59), respectively. The CHAQ was somewhat more responsive to change at 6 weeks (IAS group: relative efficiency 0.34 [JAFAR], 0.27 [JASI]), but less responsive at 6 months (MTX/hip group: relative efficiency 5.1 [JAFAR], 3.9 [JASI]). All 3 questionnaires showed acceptable parent-child agreement, and overall, there were few differences between the 3 questionnaires. The functional outcome measures currently used for JIA are all adequately responsive for use in trials or in the clinic setting. The choice of which measure to use should therefore be based on the time available for completion, the intended clinical/research use, and the depth of content required.
Comparison of Response Surface Construction Methods for Derivative Estimation Using Moving Least Squares, Kriging and Radial Basis Functions

NASA Technical Reports Server (NTRS)

Krishnamurthy, Thiagarajan

2005-01-01

Response construction methods using Moving Least Squares (MLS), Kriging and Radial Basis Functions (RBF) are compared with the Global Least Squares (GLS) method in three numerical examples for derivative generation capability. Also, a new Interpolating Moving Least Squares (IMLS) method adopted from the meshless method is presented. It is found that the response surface construction methods using the Kriging and RBF interpolation yields more accurate results compared with MLS and GLS methods. Several computational aspects of the response surface construction methods also discussed.
Planning for Reform of the Governance of the Military Health System

DTIC Science & Technology

2012-03-02

functions that are determined to be assigned to the ASD(HA). In addition, the DHA will assume responsibility for shared services , functions, and...operational capability for the DHA, the shared services and other functions and activities for which the DHA will have responsibility, the potential use of...and business processes and the consolidation and standardization of various shared services . They are also informed by a recognition that there
Bacterial endophyte communities of three agricultural important grass species differ in their response towards management regimes

NASA Astrophysics Data System (ADS)

Wemheuer, Franziska; Kaiser, Kristin; Karlovsky, Petr; Daniel, Rolf; Vidal, Stefan; Wemheuer, Bernd

2017-01-01

Endophytic bacteria are critical for plant growth and health. However, compositional and functional responses of bacterial endophyte communities towards agricultural practices are still poorly understood. Hence, we analyzed the influence of fertilizer application and mowing frequency on bacterial endophytes in three agriculturally important grass species. For this purpose, we examined bacterial endophytic communities in aerial plant parts of Dactylis glomerata L., Festuca rubra L., and Lolium perenne L. by pyrotag sequencing of bacterial 16S rRNA genes over two consecutive years. Although management regimes influenced endophyte communities, observed responses were grass species-specific. This might be attributed to several bacteria specifically associated with a single grass species. We further predicted functional profiles from obtained 16S rRNA data. These profiles revealed that predicted abundances of genes involved in plant growth promotion or nitrogen metabolism differed between grass species and between management regimes. Moreover, structural and functional community patterns showed no correlation to each other indicating that plant species-specific selection of endophytes is driven by functional rather than phylogenetic traits. The unique combination of 16S rRNA data and functional profiles provided a holistic picture of compositional and functional responses of bacterial endophytes in agricultural relevant grass species towards management practices.
Dung beetles as drivers of ecosystem multifunctionality: Are response and effect traits interwoven?

PubMed

Piccini, Irene; Nervo, Beatrice; Forshage, Mattias; Celi, Luisella; Palestrini, Claudia; Rolando, Antonio; Roslin, Tomas

2018-03-01

Rapid biodiversity loss has emphasized the need to understand how biodiversity affects the provisioning of ecological functions. Of particular interest are species and communities with versatile impacts on multiple parts of the environment, linking processes in the biosphere, lithosphere, and atmosphere to human interests in the anthroposphere (in this case, cattle farming). In this study, we examine the role of a specific group of insects - beetles feeding on cattle dung - on multiple ecological functions spanning these spheres (dung removal, soil nutrient content and greenhouse gas emissions). We ask whether the same traits which make species prone to extinction (i.e. response traits) may also affect their functional efficiency (as effect traits). To establish the link between response and effect traits, we first evaluated whether two traits (body mass and nesting strategy, the latter categorized as tunnelers or dwellers) affected the probability of a species being threatened. We then tested for a relationship between these traits and ecosystem functioning. Across Scandinavian dung beetle species, 75% of tunnelers and 30% of dwellers are classified as threatened. Hence, nesting strategy significantly affects the probability of a species being threatened, and constitutes a response trait. Effect traits varied with the ecological function investigated: density-specific dung removal was influenced by both nesting strategy and body mass, whereas methane emissions varied with body mass and nutrient recycling with nesting strategy. Our findings suggest that among Scandinavian dung beetles, nesting strategy is both a response and an effect trait, with tunnelers being more efficient in providing several ecological functions and also being more sensitive to extinction. Consequently, functionally important tunneler species have suffered disproportionate declines, and species not threatened today may be at risk of becoming so in the near future. This linkage between effect and response traits aggravates the consequences of ongoing biodiversity loss. Copyright © 2017 Elsevier B.V. All rights reserved.
Comprehensive evaluation of poly(I:C) induced inflammatory response in an airway epithelial model

PubMed Central

Lever, Amanda R; Park, Hyoungshin; Mulhern, Thomas J; Jackson, George R; Comolli, James C; Borenstein, Jeffrey T; Hayden, Patrick J; Prantil-Baun, Rachelle

2015-01-01

Respiratory viruses invade the upper airway of the lung, triggering a potent immune response that often exacerbates preexisting conditions such as asthma and COPD. Poly(I:C) is a synthetic analog of viral dsRNA that induces the characteristic inflammatory response associated with viral infection, such as loss of epithelial integrity, and increased production of mucus and inflammatory cytokines. Here, we explore the mechanistic responses to poly(I:C) in a well-defined primary normal human bronchial epithelial (NHBE) model that recapitulates in vivo functions and responses. We developed functional and quantifiable methods to evaluate the physiology of our model in both healthy and inflamed states. Through gene and protein expression, we validated the differentiation state and population of essential cell subtypes (i.e., ciliated, goblet, club, and basal cells) as compared to the human lung. Assays for total mucus production, cytokine secretion, and barrier function were used to evaluate in vitro physiology and response to viral insult. Cells were treated apically with poly(I:C) and evaluated 48 h after induction. Results revealed a dose-dependent increase in goblet cell differentiation, as well as, an increase in mucus production relative to controls. There was also a dose-dependent increase in secretion of IL-6, IL-8, TNF-α, and RANTES. Epithelial barrier function, as measured by TEER, was maintained at 1501 ± 355 Ω*cm² postdifferentiation, but dropped significantly when challenged with poly(I:C). This study provides first steps toward a well-characterized model with defined functional methods for understanding dsRNA stimulated inflammatory responses in a physiologically relevant manner. PMID:25847914
Changes in leisure-time physical activity and physical and mental health functioning: a follow-up study.

PubMed

Holstila, A; Mänty, M; Rahkonen, O; Lahelma, E; Lahti, J

2017-12-01

Functioning will be an increasingly important issue in Finland over the coming decades as the proportion of the population aged 65 and older is growing significantly. However, the associations between changes in physical activity and subsequent health functioning are poorly understood. The aim of this study was to examine how changes in physical activity relate to concurrent and prospective levels of health functioning. Cohort data from the Helsinki Health Study were used. Phase 1 (n = 8960, response rate 67%, 80% women) was conducted among 40- to 60-year-old employees of the City of Helsinki in 2000-2002, phase 2 in 2007 (n = 7332, response rate 83%), and phase 3 in 2012 (n = 6814, response rate 79%). Linear mixed models were used as the main statistical method. Increasing physical activity was associated with higher concurrent and prospective levels of physical health functioning, whereas decreasing activity was associated with lower levels of physical health functioning. The associations were stronger with physical than with mental health functioning. Promoting physical activity among aging people may help to maintain their level of health functioning. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Attention enhances contrast appearance via increased input baseline of neural responses

PubMed Central

Cutrone, Elizabeth K.; Heeger, David J.; Carrasco, Marisa

2014-01-01

Covert spatial attention increases the perceived contrast of stimuli at attended locations, presumably via enhancement of visual neural responses. However, the relation between perceived contrast and the underlying neural responses has not been characterized. In this study, we systematically varied stimulus contrast, using a two-alternative, forced-choice comparison task to probe the effect of attention on appearance across the contrast range. We modeled performance in the task as a function of underlying neural contrast-response functions. Fitting this model to the observed data revealed that an increased input baseline in the neural responses accounted for the enhancement of apparent contrast with spatial attention. PMID:25549920
Objective Measures of Visual Function in Papilledema

PubMed Central

Moss, Heather E.

2016-01-01

Synopsis Visual function is an important parameter to consider when managing patients with papilledema. Though the current standard of care uses standard automated perimetry (SAP) to obtain this information, this test is inherently subjective and prone to patient errors. Objective visual function tests including the visual evoked potential, pattern electroretinogram, photopic negative response of the full field electroretinogram, and pupillary light response have the potential to replace or supplement subjective visual function tests in papilledema management. This article reviews the evidence for use of objective visual function tests to assess visual function in papilledema and discusses future investigations needed to develop them as clinically practical and useful measures for this purpose. PMID:28451649
Exploring a regulatory role for mast cells: 'MCregs'?

PubMed

Frossi, Barbara; Gri, Giorgia; Tripodo, Claudio; Pucillo, Carlo

2010-03-01

Regulatory cells can mould the fate of the immune response by direct suppression of specific subsets of effector cells, or by redirecting effectors against invading pathogens and infected or neoplastic cells. These functions have been classically, although not exclusively, ascribed to different subsets of T cells. Recently, mast cells have been shown to regulate physiological and pathological immune responses, and thus to act at the interface between innate and adaptive immunity assuming different functions and behaviors at discrete stages of the immune response. Here, we focus on these poorly defined, and sometimes apparently conflicting, functions of mast cells. Copyright 2010 Elsevier Ltd. All rights reserved.
Transfer function analysis of the autonomic response to respiratory activity during random interval breathing

NASA Technical Reports Server (NTRS)

Chen, M. H.; Berger, R. D.; Saul, J. P.; Stevenson, K.; Cohen, R. J.

1987-01-01

We report a new method for the noninvasive characterization of the frequency response of the autonomic nervous system (ANS) in mediating fluctuations in heart rate (HR). The approach entails computation of the transfer function magnitude and phase between instantaneous lung volume and HR. Broad band fluctuations in lung volume were initiated when subjects breathed on cue to a sequence of beeps spaced randomly in time. We studied 10 subjects in both supine and standing positions. The transfer function, averaged among all the subjects, showed systematic differences between the two postures, reflecting the differing frequency responses of the sympathetic and parasympathetic divisions of the ANS.
ROS is Required for Alternatively Activated Macrophage Differentiation | Center for Cancer Research

Cancer.gov

Macrophages are key regulators in host inflammatory responses. Granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF) are responsible for inducing macrophage differentiation from monocytes. GM-CSF or M-CSF-differentiated macrophages can be further differentiated, or polarized, to more specialized cells. Classically activated, or M1, macrophages have immune-stimulatory properties and cytotoxic function against tumor cells. Alternatively activated, or M2, macrophages have low cytotoxic function but high tissue-remodeling activity. There are also M2-like cells called tumor-associated macrophages (TAMs) that are responsible for many tumor-promoting activities. Blocking the function of TAMs inhibits tumorigenesis.
The role of nerve monitoring to predict postoperative recurrent laryngeal nerve function in thyroid and parathyroid surgery.

PubMed

Eid, Issam; Miller, Frank R; Rowan, Stephanie; Otto, Randal A

2013-10-01

To determine the role and efficacy of intraoperative recurrent laryngeal nerve (RLN) stimulation in the prediction of early and permanent postoperative nerve function in thyroid and parathyroid surgery. A retrospective review of thyroid and parathyroid surgeries was performed with calculation of sensitivity and specificity of the response of intraoperative stimulation for different pathological groups. Normal electromyography (EMG) response with 0.5 mAmp stimulation was considered a positive stimulation response with postoperative function determined by laryngoscopy. No EMG response at >1-2 mAmps was considered a negative response. The rates of early and permanent paralysis, as well as sensitivity, specificity, and positive and negative predictive values for postoperative nerve function were calculated for separate pathological groups. The number of nerves at risk analyzed was 909. The overall early and permanent paralysis rates were 3.1% and 1.2%, respectively, with the highest rate being for Grave's disease cases. The overall sensitivity was 98.4%. The specificity was lower at 62.5% but acceptable in thyroid carcinoma and Grave's disease patients. The majority of nerves with a positive stimulation result and postoperative paralysis on laryngoscopy recovered function in 3 to 12 weeks, showing positive stimulation to be a good predictor of eventual recovery. Stimulation of the RLN during thyroid and parathyroid surgery is a useful tool in predicting postoperative RLN function. The sensitivity of stimulation is high, showing positive stimulation to be an excellent predictor of normal nerve function. Negative stimulation is more predictive of paralysis in cases of thyroid carcinoma and Grave's disease. 2b. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.
Cross-cultural adaptation, validation, and responsiveness of the Korean version of the AUSCAN Osteoarthritis Index.

PubMed

Moon, Ki Won; Lee, Shin-Seok; Kim, Jin Hyun; Song, Ran; Lee, Eun Young; Song, Yeong Wook; Bellamy, Nicholas; Lee, Eun Bong

2012-11-01

The Australian/Canadian Osteoarthritis Hand Index (AUSCAN) is a patient self-reported 15-item questionnaire measuring the severity of hand osteoarthritis symptoms in the respect of pain, stiffness, and function. In this study, we developed a Korean version of the AUSCAN Index (K-AUSCAN) and confirmed its reliability, validity, and responsiveness. The AUSCAN Index was translated into Korean by 3 translators and translated back into English by 3 different translators. In a group of 53 patients with clinical hand osteoarthritis (mean age 58.3 ± 7.6 years), validity was evaluated against other outcome measures, including the Functional Index for Hand Osteoarthritis (FIHOA) and Multidimensional Health Assessment Questionnaire (MDHAQ). Test-retest reliability was assessed at a 2-weeks interval in 51 patients. Internal consistency of K-AUSCAN was evaluated by Cronbach's α. Responsiveness was measured by standardized response mean (SRM). The test-retest reliability of K-AUSCAN yielded intraclass correlation coefficient of 0.46 for pain, 0.58 for stiffness, and 0.67 for function. The internal consistency of K-AUSCAN was satisfactory with Cronbach's α of 0.89 for pain and 0.93 for function. The K-AUSCAN index showed good correlation with other measures (r (2) was 0.67 for K-AUSCAN pain and MDHAQ pain; r (2) was 0.72 for K-AUSCAN function and FIHOA). The pain and function of K-AUSCAN correlated substantially with each other and moderately with stiffness subscale. The average SRM for K-AUSCAN pain, stiffness, and function was -0.92, -0.48, and -0.84, respectively. The Korean version of the AUSCAN Index is a valid, reliable, and responsive tool for the assessment of hand osteoarthritis symptoms.
The added value of impedance-pH monitoring to Rome III criteria in distinguishing functional heartburn from non-erosive reflux disease.

PubMed

Savarino, Edoardo; Marabotto, Elisa; Zentilin, Patrizia; Frazzoni, Marzio; Sammito, Giorgio; Bonfanti, Daria; Sconfienza, Luca; Assandri, Lorenzo; Gemignani, Lorenzo; Malesci, Alberto; Savarino, Vincenzo

2011-07-01

Functional heartburn is defined by Rome III criteria as an endoscopy-negative condition with normal oesophageal acid exposure time, negative symptom association to acid reflux and unsatisfactory response to proton pump inhibitors. These criteria underestimated the role of non-acid reflux. To assess the contribution of impedance-pH with symptom association probability (SAP) analysis in identifying endoscopy-negative patients with reflux disease and separating them from functional heartburn. Consecutive endoscopy-negative patients treated with proton pump inhibitors (n=219) undergoing impedance-pH monitoring off-therapy were analysed. Distal acid exposure time, reflux episodes, SAP and symptomatic response to proton pump inhibitors were measured. Based on impedance-pH/SAP, 67 (31%) patients were pH+/SAP+, 6 (2%) pH+/SAP-, 83 (38%) hypersensitive oesophagus and 63 (29%) functional heartburn. According to pH-metry alone/response to proton pump inhibitors, 62 (28%) were pH+/SAP+, 11 (5%) pH+/SAP-, 61 (28%) hypersensitive oesophagus and 85 (39%) functional heartburn. In the normal-acid exposure population the contribution of impedance-pH/SAP compared to pH-metry alone/response to proton pump inhibitors in identifying patients with reflux disease and functional heartburn resulted to be 10%. In patients with abnormal-acid exposure, the contribution of impedance-pH/SAP increased by 3%. Comparing impedance-pH testing with pH-metry alone plus the response to proton pump inhibitor therapy demonstrated that the latter ones cause underestimation of reflux disease patients and overestimation of functional heartburn patients. Copyright © 2011 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.
24 CFR 92.356 - Conflict of interest.

Code of Federal Regulations, 2014 CFR

2014-04-01

... functions or responsibilities with respect to activities assisted with HOME funds or who are in a position to participate in a decision-making process or gain inside information with regard to these... affected person has withdrawn from his or her functions or responsibilities, or the decisionmaking process...
24 CFR 92.356 - Conflict of interest.

Code of Federal Regulations, 2013 CFR

2013-04-01

... functions or responsibilities with respect to activities assisted with HOME funds or who are in a position to participate in a decisionmaking process or gain inside information with regard to these activities... affected person has withdrawn from his or her functions or responsibilities, or the decisionmaking process...
24 CFR 92.356 - Conflict of interest.

Code of Federal Regulations, 2012 CFR

2012-04-01

... functions or responsibilities with respect to activities assisted with HOME funds or who are in a position to participate in a decisionmaking process or gain inside information with regard to these activities... affected person has withdrawn from his or her functions or responsibilities, or the decisionmaking process...
24 CFR 574.625 - Conflict of interest.

Code of Federal Regulations, 2013 CFR

2013-04-01

... functions or responsibilities with respect to assisted activities, or who is in a position to participate in a decision making process or gain inside information with regard to such activities, may obtain a... the affected person has withdrawn from his or her functions or responsibilities, or the decisionmaking...
24 CFR 574.625 - Conflict of interest.

Code of Federal Regulations, 2014 CFR

2014-04-01

... functions or responsibilities with respect to assisted activities, or who is in a position to participate in a decision making process or gain inside information with regard to such activities, may obtain a... the affected person has withdrawn from his or her functions or responsibilities, or the decisionmaking...
24 CFR 574.625 - Conflict of interest.

Code of Federal Regulations, 2011 CFR

2011-04-01

... functions or responsibilities with respect to assisted activities, or who is in a position to participate in a decision making process or gain inside information with regard to such activities, may obtain a... the affected person has withdrawn from his or her functions or responsibilities, or the decisionmaking...
24 CFR 92.356 - Conflict of interest.

Code of Federal Regulations, 2011 CFR

2011-04-01

... functions or responsibilities with respect to activities assisted with HOME funds or who are in a position to participate in a decisionmaking process or gain inside information with regard to these activities... affected person has withdrawn from his or her functions or responsibilities, or the decisionmaking process...
24 CFR 574.625 - Conflict of interest.

Code of Federal Regulations, 2012 CFR

2012-04-01

... functions or responsibilities with respect to assisted activities, or who is in a position to participate in a decision making process or gain inside information with regard to such activities, may obtain a... the affected person has withdrawn from his or her functions or responsibilities, or the decisionmaking...
Final state interactions and inclusive nuclear collisions

NASA Technical Reports Server (NTRS)

Cucinotta, Francis A.; Dubey, Rajendra R.

1993-01-01

A scattering formalism is developed in a multiple scattering model to describe inclusive momentum distributions for high-energy projectiles. The effects of final state interactions on response functions and momentum distributions are investigated. Calculations for high-energy protons that include shell model response functions are compared with experiments.
Functional networks in parallel with cortical development associate with executive functions in children.

PubMed

Zhong, Jidan; Rifkin-Graboi, Anne; Ta, Anh Tuan; Yap, Kar Lai; Chuang, Kai-Hsiang; Meaney, Michael J; Qiu, Anqi

2014-07-01

Children begin performing similarly to adults on tasks requiring executive functions in late childhood, a transition that is probably due to neuroanatomical fine-tuning processes, including myelination and synaptic pruning. In parallel to such structural changes in neuroanatomical organization, development of functional organization may also be associated with cognitive behaviors in children. We examined 6- to 10-year-old children's cortical thickness, functional organization, and cognitive performance. We used structural magnetic resonance imaging (MRI) to identify areas with cortical thinning, resting-state fMRI to identify functional organization in parallel to cortical development, and working memory/response inhibition tasks to assess executive functioning. We found that neuroanatomical changes in the form of cortical thinning spread over bilateral frontal, parietal, and occipital regions. These regions were engaged in 3 functional networks: sensorimotor and auditory, executive control, and default mode network. Furthermore, we found that working memory and response inhibition only associated with regional functional connectivity, but not topological organization (i.e., local and global efficiency of information transfer) of these functional networks. Interestingly, functional connections associated with "bottom-up" as opposed to "top-down" processing were more clearly related to children's performance on working memory and response inhibition, implying an important role for brain systems involved in late childhood. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Dual function of CD70 in viral infection: modulator of early cytokine responses and activator of adaptive responses1

PubMed Central

Allam, Atef; Swiecki, Melissa; Vermi, William; Ashwell, Jonathan D.; Colonna, Marco

2014-01-01

The role of the tumor necrosis factor family member CD70 in adaptive T cell responses has been intensively studied but its function in innate responses is still under investigation. Here we show that CD70 inhibits the early innate response to murine cytomegalovirus (MCMV) but is essential for the optimal generation of virus-specific CD8 T cells. CD70-/- mice reacted to MCMV infection with a robust type I interferon and proinflammatory cytokine response. This response was sufficient for initial control of MCMV, although at later time points, CD70-/- mice became more susceptible to MCMV infection. The heightened cytokine response during the early phase of MCMV infection in CD70-/- mice was paralleled by a reduction in regulatory T cells (Treg). Treg from naïve CD70-/- mice were not as efficient at suppressing T cell proliferation compared to Treg from naïve WT mice and depletion of Treg during MCMV infection in Foxp3-DTR mice or in WT mice recapitulated the phenotype observed in CD70-/- mice. Our study demonstrates that while CD70 is required for the activation of the antiviral adaptive response, it has a regulatory role in early cytokine responses to viruses such as MCMV, possibly through maintenance of Treg survival and function. PMID:24913981
Generalized fluid impulse functions for oscillating marine structures

NASA Astrophysics Data System (ADS)

Janardhanan, K.; Price, W. G.; Wu, Y.

1992-03-01

A selection of generalized impulse response functions is presented for a variety of rigid and flexible marine structures (i.e. mono-hull, SWATH, floating drydock and twin dock, fixed flexible pile). These functions are determined from calculated and experimental frequency-dependent hydrodynamic data, and the characteristics of these data depend on the type of structure considered. This information is reflected in the shape and duration of the generalized impulse response functions which are pre-requisites for a generalized integro-differential mathematical model describing the dynamic behaviour of the structures to seaway excitation.

Functional response of sport divers to lobsters with application to fisheries management.

PubMed

Eggleston, David B; Parsons, Darren M; Kellison, G Todd; Plaia, Gayle R; Johnson, Eric G

2008-01-01

Fishery managers must understand the dynamics of fishers and their prey to successfully predict the outcome of management actions. We measured the impact of a two-day exclusively recreational fishery on Caribbean spiny lobster in the Florida Keys, USA, over large spatial scales (>100 km) and multiple years and used a theoretical, predator-prey functional response approach to identify whether or not sport diver catch rates were density-independent (type I) or density-dependent (type II or III functional response), and if catch rates were saturated (i.e., reached an asymptote) at relatively high lobster densities. We then describe how this predator-prey framework can be applied to fisheries management for spiny lobster and other species. In the lower Keys, divers exhibited a type-I functional response, whereby they removed a constant and relatively high proportion of lobsters (0.74-0.84) across all pre-fishing-season lobster densities. Diver fishing effort increased in a linear manner with lobster prey densities, as would be expected with a type-I functional response, and was an order of magnitude lower in the upper Keys than lower Keys. There were numerous instances in the upper Keys where the density of lobsters actually increased from before to after the fishing season, suggesting some type of "spill-in effect" from surrounding diver-disturbed areas. With the exception of isolated reefs in the upper Keys, the proportion of lobsters removed by divers was density independent (type-I functional response) and never reached saturation at natural lobster densities. Thus, recreational divers have a relatively simple predatory response to spiny lobster, whereby catch rates increase linearly with lobster density such that catch is a reliable indicator of abundance. Although diver predation is extremely high (approximately 80%), diver predation pressure is not expected to increase proportionally with a decline in lobster density (i.e., a depensatory response), which could exacerbate local extinction. Furthermore, management actions that reduce diver effort should have a concomitant and desired reduction in catch. The recreational diver-lobster predator-prey construct in this study provides a useful predictive framework to apply to both recreational and commercial fisheries, and on which to build as management actions are implemented.
Contrasting patterns of leaf trait variation among and within species during tropical dry forest succession in Costa Rica.

PubMed

Derroire, Géraldine; Powers, Jennifer S; Hulshof, Catherine M; Cárdenas Varela, Luis E; Healey, John R

2018-01-10

A coordinated response to environmental drivers amongst individual functional traits is central to the plant strategy concept. However, whether the trait co-ordination observed at the global scale occurs at other ecological scales (especially within species) remains an open question. Here, for sapling communities of two tropical dry forest types in Costa Rica, we show large differences amongst traits in the relative contribution of species turnover and intraspecific variation to their directional changes in response to environmental changes along a successional gradient. We studied the response of functional traits associated with the leaf economics spectrum and drought tolerance using intensive sampling to analyse inter- and intra-specific responses to environmental changes and ontogeny. Although the overall functional composition of the sapling communities changed during succession more through species turnover than through intraspecific trait variation, their relative contributions differed greatly amongst traits. For instance, community mean specific leaf area changed mostly due to intraspecific variation. Traits of the leaf economics spectrum showed decoupled responses to environmental drivers and ontogeny. These findings emphasise how divergent ecological mechanisms combine to cause great differences in changes of individual functional traits over environmental gradients and ecological scales.
Kruppel-like factor 15 is required for the cardiac adaptive response to fasting.

PubMed

Sugi, Keiki; Hsieh, Paishiun N; Ilkayeva, Olga; Shelkay, Shamanthika; Moroney, Bridget; Baadh, Palvir; Haynes, Browning; Pophal, Megan; Fan, Liyan; Newgard, Christopher B; Prosdocimo, Domenick A; Jain, Mukesh K

2018-01-01

Cardiac metabolism is highly adaptive in response to changes in substrate availability, as occur during fasting. This metabolic flexibility is essential to the maintenance of contractile function and is under the control of a group of select transcriptional regulators, notably the nuclear receptor family of factors member PPARα. However, the diversity of physiologic and pathologic states through which the heart must sustain function suggests the possible existence of additional transcriptional regulators that play a role in matching cardiac metabolism to energetic demand. Here we show that cardiac KLF15 is required for the normal cardiac response to fasting. Specifically, we find that cardiac function is impaired upon fasting in systemic and cardiac specific Klf15-null mice. Further, cardiac specific Klf15-null mice display a fasting-dependent accumulation of long chain acylcarnitine species along with a decrease in expression of the carnitine translocase Slc25a20. Treatment with a diet high in short chain fatty acids relieves the KLF15-dependent long chain acylcarnitine accumulation and impaired cardiac function in response to fasting. Our observations establish KLF15 as a critical mediator of the cardiac adaptive response to fasting through its regulation of myocardial lipid utilization.
An investigation of the validity of six measures of physical function in people awaiting joint replacement surgery of the hip or knee.

PubMed

Gill, Stephen D; de Morton, Natalie A; Mc Burney, Helen

2012-10-01

To assess and compare the validity of six physical function measures in people awaiting hip or knee joint replacement. Eighty-two people awaiting hip or knee replacement were assessed using six physical function measures including the WOMAC Function scale, SF-36 Physical Function scale, SF-36 Physical Component Summary scale, Patient Specific Functional Scale, 30-second chair stand test, and 50-foot timed walk. Validity was assessed using a head-to-head comparison design. Convergent validity was demonstrated with significant correlations between most measures (Spearman's rho 0.22 to 0.71). The Patient Specific Functional Scale had the lowest correlations with other measures of physical function. Discriminant validity was demonstrated with low correlations between mental health and physical function scores (Spearman's rho -0.12 to 0.33). Only the WOMAC Function scale, 30-second chair stand test, and 50-foot timed walk demonstrated known groups validity when scores for participants who walked with a gait aid were compared with those who did not. Standardized response means and Guyatt's responsiveness indexes indicated that the SF-36 was the least responsive measure. For those awaiting joint replacement surgery of the hip or knee, the current investigation found that the WOMAC Function scale, 30-second chair stand test, and 50-foot timed walk demonstrated the most evidence of validity. The Patient Specific Functional Scale might complement other measures by capturing a different aspect of physical function.
Flow-mediated changes in pulse wave velocity: a new clinical measure of endothelial function.

PubMed

Naka, Katerina K; Tweddel, Ann C; Doshi, Sagar N; Goodfellow, Jonathan; Henderson, Andrew H

2006-02-01

To test whether measuring hyperaemic changes in pulse wave velocity (PWV) could be used as a new method of assessing endothelial function for use in clinical practice. Flow-mediated changes in vascular tone may be used to assess endothelial function and may be induced by distal hyperaemia, while endothelium-mediated changes in vascular tone can influence PWV. These three known principles were combined to provide and test a novel method of measuring endothelial function by the acute effects of distal hyperaemia on upper and lower limb PWV (measured by a recently developed method). Flow-mediated changes in upper and lower limb PWV were compared in 17 healthy subjects and seven patients with stable chronic heart failure (CHF), as a condition where endothelial function is impaired but endothelium-independent dilator responses are retained. Corroborative measurements of PWV and brachial artery diameter responses to endothelium-dependent and -independent pharmacological stimuli were performed in a further eight healthy subjects. Flow-mediated reduction of PWV (by 14% with no change in blood pressure) was found in normal subjects but was almost abolished in patients with CHF. PWV responses appear to be inversely related to and relatively greater than brachial artery diameter responses. The method may offer potential advantages of practical use and sensitivity over conduit artery diameter responses to measure endothelial dysfunction.
Early disrupted neurovascular coupling and changed event level hemodynamic response function in type 2 diabetes: an fMRI study.

PubMed

Duarte, João V; Pereira, João M S; Quendera, Bruno; Raimundo, Miguel; Moreno, Carolina; Gomes, Leonor; Carrilho, Francisco; Castelo-Branco, Miguel

2015-10-01

Type 2 diabetes (T2DM) patients develop vascular complications and have increased risk for neurophysiological impairment. Vascular pathophysiology may alter the blood flow regulation in cerebral microvasculature, affecting neurovascular coupling. Reduced fMRI signal can result from decreased neuronal activation or disrupted neurovascular coupling. The uncertainty about pathophysiological mechanisms (neurodegenerative, vascular, or both) underlying brain function impairments remains. In this cross-sectional study, we investigated if the hemodynamic response function (HRF) in lesion-free brains of patients is altered by measuring BOLD (Blood Oxygenation Level-Dependent) response to visual motion stimuli. We used a standard block design to examine the BOLD response and an event-related deconvolution approach. Importantly, the latter allowed for the first time to directly extract the true shape of HRF without any assumption and probe neurovascular coupling, using performance-matched stimuli. We discovered a change in HRF in early stages of diabetes. T2DM patients show significantly different fMRI response profiles. Our visual paradigm therefore demonstrated impaired neurovascular coupling in intact brain tissue. This implies that functional studies in T2DM require the definition of HRF, only achievable with deconvolution in event-related experiments. Further investigation of the mechanisms underlying impaired neurovascular coupling is needed to understand and potentially prevent the progression of brain function decrements in diabetes.
Viral and cellular SOS-regulated motor proteins: dsDNA translocation mechanisms with divergent functions.

PubMed

Wolfe, Annie; Phipps, Kara; Weitao, Tao

2014-01-01

DNA damage attacks on bacterial cells have been known to activate the SOS response, a transcriptional response affecting chromosome replication, DNA recombination and repair, cell division and prophage induction. All these functions require double-stranded (ds) DNA translocation by ASCE hexameric motors. This review seeks to delineate the structural and functional characteristics of the SOS response and the SOS-regulated DNA translocases FtsK and RuvB with the phi29 bacteriophage packaging motor gp16 ATPase as a prototype to study bacterial motors. While gp16 ATPase, cellular FtsK and RuvB are similarly comprised of hexameric rings encircling dsDNA and functioning as ATP-driven DNA translocases, they utilize different mechanisms to accomplish separate functions, suggesting a convergent evolution of these motors. The gp16 ATPase and FtsK use a novel revolution mechanism, generating a power stroke between subunits through an entropy-DNA affinity switch and pushing dsDNA inward without rotation of DNA and the motor, whereas RuvB seems to employ a rotation mechanism that remains to be further characterized. While FtsK and RuvB perform essential tasks during the SOS response, their roles may be far more significant as SOS response is involved in antibiotic-inducible bacterial vesiculation and biofilm formation as well as the perspective of the bacteria-cancer evolutionary interaction.
Interplay between grain structure and protein adsorption on functional response of osteoblasts: ultrafine-grained versus coarse-grained substrates.

PubMed

Misra, R D K; Nune, C; Pesacreta, T C; Somani, M C; Karjalainen, L P

2013-01-01

The rapid adsorption of proteins is the starting and primary biological response that occurs when a biomedical device is implanted in the physiological system. The biological response, however, depends on the surface characteristics of the device. Considering the significant interest in nano-/ultrafine surfaces and nanostructured coatings, we describe here, the interplay between grain structure and protein adsorption (bovine serum albumin: BSA) on osteoblasts functions by comparing nanograined/ultrafine-grained (NG/UFG) and coarse-grained (CG: grain size in the micrometer range) substrates by investigating cell-substrate interactions. The protein adsorption on NG/UFG surface was beneficial in favorably modulating biological functions including cell attachment, proliferation, and viability, whereas the effect was less pronounced on protein adsorbed CG surface. Additionally, immunofluorescence studies demonstrated stronger vinculin signals associated with actin stress fibers in the outer regions of the cells and cellular extensions on protein adsorbed NG/UFG surface. The functional response followed the sequence: NG/UFG(BSA) > NG/UFG > CG(BSA) > CG. The differences in the cellular response on bare and protein adsorbed NG/UFG and CG surfaces are attributed to cumulative contribution of grain structure and degree of hydrophilicity. The study underscores the potential advantages of protein adsorption on artificial biomedical devices to enhance the bioactivity and regulate biological functions. Copyright © 2012 Wiley Periodicals, Inc.
Open-Ended Recursive Approach for the Calculation of Multiphoton Absorption Matrix Elements

PubMed Central

2015-01-01

We present an implementation of single residues for response functions to arbitrary order using a recursive approach. Explicit expressions in terms of density-matrix-based response theory for the single residues of the linear, quadratic, cubic, and quartic response functions are also presented. These residues correspond to one-, two-, three- and four-photon transition matrix elements. The newly developed code is used to calculate the one-, two-, three- and four-photon absorption cross sections of para-nitroaniline and para-nitroaminostilbene, making this the first treatment of four-photon absorption in the framework of response theory. We find that the calculated multiphoton absorption cross sections are not very sensitive to the size of the basis set as long as a reasonably large basis set with diffuse functions is used. The choice of exchange–correlation functional, however, significantly affects the calculated cross sections of both charge-transfer transitions and other transitions, in particular, for the larger para-nitroaminostilbene molecule. We therefore recommend the use of a range-separated exchange–correlation functional in combination with the augmented correlation-consistent double-ζ basis set aug-cc-pVDZ for the calculation of multiphoton absorption properties. PMID:25821415
Kinetic damping in the spectra of the spherical impedance probe

NASA Astrophysics Data System (ADS)

Oberrath, J.

2018-04-01

The impedance probe is a measurement device to measure plasma parameters, such as electron density. It consists of one electrode connected to a network analyzer via a coaxial cable and is immersed into a plasma. A bias potential superposed with an alternating potential is applied to the electrode and the response of the plasma is measured. Its dynamical interaction with the plasma in an electrostatic, kinetic description can be modeled in an abstract notation based on functional analytic methods. These methods provide the opportunity to derive a general solution, which is given as the response function of the probe–plasma system. It is defined by the matrix elements of the resolvent of an appropriate dynamical operator. Based on the general solution, a residual damping for vanishing pressure can be predicted and can only be explained by kinetic effects. In this paper, an explicit response function of the spherical impedance probe is derived. Therefore, the resolvent is determined by its algebraic representation based on an expansion in orthogonal basis functions. This allows one to compute an approximated response function and its corresponding spectra. These spectra show additional damping due to kinetic effects and are in good agreement with former kinetically determined spectra.
An investigation of soil-structure interaction effects observed at the MIT Green Building

USGS Publications Warehouse

Taciroglu, Ertugrul; Çelebi, Mehmet; Ghahari, S. Farid; Abazarsa, Fariba

2016-01-01

The soil-foundation impedance function of the MIT Green Building is identified from its response signals recorded during an earthquake. Estimation of foundation impedance functions from seismic response signals is a challenging task, because: (1) the foundation input motions (FIMs) are not directly measurable, (2) the as-built properties of the super-structure are only approximately known, and (3) the soil-foundation impedance functions are inherently frequency-dependent. In the present study, aforementioned difficulties are circumvented by using, in succession, a blind modal identification (BMID) method, a simplified Timoshenko beam model (TBM), and a parametric updating of transfer functions (TFs). First, the flexible-base modal properties of the building are identified from response signals using the BMID method. Then, a flexible-base TBM is updated using the identified modal data. Finally, the frequency-dependent soil-foundation impedance function is estimated by minimizing the discrepancy between TFs (of pairs instrumented floors) that are (1) obtained experimentally from earthquake data and (2) analytically from the updated TBM. Using the fully identified flexible-base TBM, the FIMs as well as building responses at locations without instruments can be predicted, as demonstrated in the present study.
A model-independent comparison of the rates of uptake and short term retention of 47Ca and 85Sr by the skeleton.

PubMed

Reeve, J; Hesp, R

1976-12-22

1. A method has been devised for comparing the impulse response functions of the skeleton for two or more boneseeking tracers, and for estimating the contribution made by measurement errors to the differences between any pair of impulse response functions. 2. Comparisons were made between the calculated impulse response functions for 47Ca and 85Sr obtained in simultaneous double tracer studies in sixteen subjects. Collectively the differences between the 47Ca and 85Sr functions could be accounted for entirely by measurement errors. 3. Because the calculation of an impulse response function requires fewer a priori assumptions than other forms of mathematical analysis, and automatically corrects for differences induced by recycling of tracer and non-identical rates of excretory plasma clearance of tracer, it is concluded that differences shown in previous in vivo studies between the fluxes of Ca and Sr into bone can be fully accounted for by undetermined oversimplifications in the various mathematical models used to analyse the results of those studies. 85Sr is therefore an adequate tracer for bone calcium in most in vivo studies.
Responsiveness of physical function outcomes following physiotherapy intervention for osteoarthritis of the knee: an outcome comparison study.

PubMed

French, Helen P; Fitzpatrick, Martina; FitzGerald, Oliver

2011-12-01

To compare the responsiveness of two self-report measures and three physical performance measures of function following physiotherapy for osteoarthritis of the knee. Single centre study in acute hospital setting. Patients referred for physiotherapy with osteoarthritis of the knee were recruited. The Western Ontario and McMaster Universities (WOMAC), Lequesne Algofunctional Index (LAI), timed-up-and-go test (TUGT), timed-stand test (TST) and six-minute walk test (6MWT) were administered at first and final physiotherapy visits. Wilcoxon Signed Rank tests were used to determine the effect of physiotherapy on each outcome. Responsiveness was calculated using effect size, standardised response mean and a median-based measure of responsiveness due to some outlying data. Thirty-nine patients with a mean age of 65.3 (standard deviation 6.9) years were investigated before and after a course of exercise-based physiotherapy. There was a significant improvement in all outcomes except the WOMAC scores. All measures demonstrated small effect sizes for all statistics (<0.50), except the 6MWT which was in the moderate range for one of the indices (standardised response mean 0.54). The LAI was more responsive than the WOMAC total score and the WOMAC physical function subscale for all responsiveness statistics, whilst the 6MWT was more responsive than the TST and the TUGT. The median-based effect size index produced the smallest effect sizes for all measures (0.1 to 0.43). These results can be used to guide decision making about which physical function outcome measures should be used to evaluate effectiveness of rehabilitation of people with osteoarthritis of the knee at group level in a clinical setting. Copyright Â© 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.
Sustained and transient attention in the continuous performance task.

PubMed

Smid, H G O M; de Witte, M R; Homminga, I; van den Bosch, R J

2006-08-01

One of the most frequently applied methods to study abnormal cognition is the Continuous Performance Task (CPT). It is unclear, however, which cognitive functions are engaged in normal CPT performance. The aims of the present study were to identify the neurocognitive functions engaged in the main variants of the CPT and to determine to what extent these variants differentially engage these functions. We hypothesized that the main CPT versions (CPT-X, CPT-AX, CPT-Identical Pairs) can be distinguished by whether they demand sustained or transient attention and sustained or transient response preparation. Transient attention to objects like letters or digits, that is, the need to switch attention to different objects from trial to trial, impairs target detection accuracy relative to sustained attention to a single object. Transient response preparation, that is, the possibility to switch response preparation on and off from trial to trial, improves response speed relative to having to sustain response preparation across all trials. Comparison of task performance and Event-Related brain Potentials (ERPs) of healthy participants obtained in the main CPT variants confirmed these hypotheses. Behavioral and ERP measures indicated worse target detection in the CPT-AX than in the CPT-X, consistent with a higher demand on transient attention in that task. In contrast, behavioral and ERP measures indicated higher response speed in the CPT-AX than in the CPT-X, associated with more response preparation in advance of the targets. This supports the idea of increased transient response preparation in the CPT-AX. We conclude that CPTs differ along at least two task variables that each influences a different cognitive function.
Mammalian TRPV4 (VR-OAC) directs behavioral responses to osmotic and mechanical stimuli in Caenorhabditis elegans

PubMed Central

Liedtke, Wolfgang; Tobin, David M.; Bargmann, Cornelia I.; Friedman, Jeffrey M.

2003-01-01

All animals detect osmotic and mechanical stimuli, but the molecular basis for these responses is incompletely understood. The vertebrate transient receptor potential channel vanilloid subfamily 4 (TRPV4) (VR-OAC) cation channel has been suggested to be an osmo/mechanosensory channel. To assess its function in vivo, we expressed TRPV4 in Caenorhabditis elegans sensory neurons and examined its ability to generate behavioral responses to sensory stimuli. C. elegans ASH neurons function as polymodal sensory neurons that generate a characteristic escape behavior in response to mechanical, osmotic, or olfactory stimuli. These behaviors require the TRPV channel OSM-9 because osm-9 mutants do not avoid nose touch, high osmolarity, or noxious odors. Expression of mammalian TRPV4 in ASH neurons of osm-9 worms restored avoidance responses to hypertonicity and nose touch, but not the response to odorant repellents. Mutations known to reduce TRPV4 channel activity also reduced its ability to direct nematode avoidance behavior. TRPV4 function in ASH required the endogenous C. elegans osmotic and nose touch avoidance genes ocr-2, odr-3, osm-10, and glr-1, indicating that TRPV4 is integrated into the normal ASH sensory apparatus. The osmotic and mechanical avoidance responses of TRPV4-expressing animals were different in their sensitivity and temperature dependence from the responses of wild-type animals, suggesting that the TRPV4 channel confers its characteristic properties on the transgenic animals' behavior. These results provide evidence that TRPV4 can function as a component of an osmotic/mechanical sensor in vivo. PMID:14581619
Threshold responses of Amazonian stream fishes to timing and extent of deforestation.

PubMed

Brejão, Gabriel L; Hoeinghaus, David J; Pérez-Mayorga, María Angélica; Ferraz, Silvio F B; Casatti, Lilian

2017-12-06

Deforestation is a primary driver of biodiversity change through habitat loss and fragmentation. Stream biodiversity may not respond to deforestation in a simple linear relationship. Rather, threshold responses to extent and timing of deforestation may occur. Identification of critical deforestation thresholds is needed for effective conservation and management. We tested for threshold responses of fish species and functional groups to degree of watershed and riparian zone deforestation and time since impact in 75 streams in the western Brazilian Amazon. We used remote sensing to assess deforestation from 1984 to 2011. Fish assemblages were sampled with seines and dip nets in a standardized manner. Fish species (n = 84) were classified into 20 functional groups based on ecomorphological traits associated with habitat use, feeding, and locomotion. Threshold responses were quantified using threshold indicator taxa analysis. Negative threshold responses to deforestation were common and consistently occurred at very low levels of deforestation (<20%) and soon after impact (<10 years). Sensitive species were functionally unique and associated with complex habitats and structures of allochthonous origin found in forested watersheds. Positive threshold responses of species were less common and generally occurred at >70% deforestation and >10 years after impact. Findings were similar at the community level for both taxonomic and functional analyses. Because most negative threshold responses occurred at low levels of deforestation and soon after impact, even minimal change is expected to negatively affect biodiversity. Delayed positive threshold responses to extreme deforestation by a few species do not offset the loss of sensitive taxa and likely contribute to biotic homogenization. © 2017 Society for Conservation Biology.
Identification of boiler inlet transfer functions and estimation of system parameters

NASA Technical Reports Server (NTRS)

Miles, J. H.

1972-01-01

An iterative computer method is described for identifying boiler transfer functions using frequency response data. An objective penalized performance measure and a nonlinear minimization technique are used to cause the locus of points generated by a transfer function to resemble the locus of points obtained from frequency response measurements. Different transfer functions can be tried until a satisfactory empirical transfer function of the system is found. To illustrate the method, some examples and some results from a study of a set of data consisting of measurements of the inlet impedance of a single tube forced flow boiler with inserts are given.
Assessment of platelet function in healthy cats in response to commonly prescribed antiplatelet drugs using three point-of-care platelet function tests.

PubMed

Ho, Kimberly K; Abrams-Ogg, Anthony Cg; Wood, R Darren; O'Sullivan, M Lynne; Kirby, Gordon M; Blois, Shauna L

2017-06-01

Objectives The objective was to determine if decreased platelet function could be detected after treatment with aspirin and/or clopidogrel in healthy cats using three point-of-care platelet function tests that evaluate platelet function by different methods: Multiplate (by impedance), Platelet Function Analyzer 100 (by mechanical aperture closure) and Plateletworks (by platelet counting). Methods Thirty-six healthy cats were randomly assigned to receive one of three oral treatments over an 8 day period: (1) aspirin 5 mg q72h; (2) aspirin 20.25 mg q72h; or (3) clopidogrel 18.75 mg q24h. Cats treated with 5 and 20.25 mg aspirin also received clopidogrel on days 4-8. Platelet aggregation in response to adenosine diphosphate and collagen ± arachidonic acid was assessed on days 1 (baseline), 4 and 8. Aspirin and clopidogrel metabolites were measured by high-performance liquid chromatography. Platelet function in response to treatment was analyzed by ANCOVA, linear regression and Spearman correlation. Results The only solitary aspirin effect was detected using Plateletworks with collagen in cats treated with 20.25 mg. The only effect detected by Multiplate was using arachidonic acid in cats treated with both aspirin 20.25 mg and clopidogrel. All clopidogrel treatment effects were detected by Platelet Function Analyzer 100, Plateletworks (adenosine diphosphate) and Plateletworks (collagen). Drug metabolites were present in all cats, but concentrations were minimally correlated to platelet function test results. Conclusions and relevance Platelet Function Analyzer 100 and Plateletworks using adenosine diphosphate ± collagen agonists may be used to detect decreased platelet function in response to clopidogrel treatment. Either aspirin is not as effective an antiplatelet drug as clopidogrel, or the tests used were not optimal to measure aspirin effect. Cats with heart disease are commonly prescribed antiplatelet drugs to decrease the risk of aortic thromboembolism. Platelet Function Analyzer 100 and Plateletworks may be useful for confirming clopidogrel treatment in these cats.
Arabidopsis nph1 and npl1: blue light receptors that mediate both phototropism and chloroplast relocation.

PubMed

Sakai, T; Kagawa, T; Kasahara, M; Swartz, T E; Christie, J M; Briggs, W R; Wada, M; Okada, K

2001-06-05

UV-A/blue light acts to regulate a number of physiological processes in higher plants. These include light-driven chloroplast movement and phototropism. The NPH1 gene of Arabidopsis encodes an autophosphorylating protein kinase that functions as a photoreceptor for phototropism in response to low-intensity blue light. However, nph1 mutants have been reported to exhibit normal phototropic curvature under high-intensity blue light, indicating the presence of an additional phototropic receptor. A likely candidate is the nph1 homologue, npl1, which has recently been shown to mediate the avoidance response of chloroplasts to high-intensity blue light in Arabidopsis. Here we demonstrate that npl1, like nph1, noncovalently binds the chromophore flavin mononucleotide (FMN) within two specialized PAS domains, termed LOV domains. Furthermore, when expressed in insect cells, npl1, like nph1, undergoes light-dependent autophosphorylation, indicating that npl1 also functions as a light receptor kinase. Consistent with this conclusion, we show that a nph1 npl1 double mutant exhibits an impaired phototropic response under both low- and high-intensity blue light. Hence, npl1 functions as a second phototropic receptor under high fluence rate conditions and is, in part, functionally redundant to nph1. We also demonstrate that both chloroplast accumulation in response to low-intensity light and chloroplast avoidance movement in response to high-intensity light are lacking in the nph1 npl1 double mutant. Our findings therefore indicate that nph1 and npl1 show partially overlapping functions in two different responses, phototropism and chloroplast relocation, in a fluence rate-dependent manner.
Dose-response relationships for environmentally mediated infectious disease transmission models

PubMed Central

Eisenberg, Joseph N. S.

2017-01-01

Environmentally mediated infectious disease transmission models provide a mechanistic approach to examining environmental interventions for outbreaks, such as water treatment or surface decontamination. The shift from the classical SIR framework to one incorporating the environment requires codifying the relationship between exposure to environmental pathogens and infection, i.e. the dose–response relationship. Much of the work characterizing the functional forms of dose–response relationships has used statistical fit to experimental data. However, there has been little research examining the consequences of the choice of functional form in the context of transmission dynamics. To this end, we identify four properties of dose–response functions that should be considered when selecting a functional form: low-dose linearity, scalability, concavity, and whether it is a single-hit model. We find that i) middle- and high-dose data do not constrain the low-dose response, and different dose–response forms that are equally plausible given the data can lead to significant differences in simulated outbreak dynamics; ii) the choice of how to aggregate continuous exposure into discrete doses can impact the modeled force of infection; iii) low-dose linear, concave functions allow the basic reproduction number to control global dynamics; and iv) identifiability analysis offers a way to manage multiple sources of uncertainty and leverage environmental monitoring to make inference about infectivity. By applying an environmentally mediated infectious disease model to the 1993 Milwaukee Cryptosporidium outbreak, we demonstrate that environmental monitoring allows for inference regarding the infectivity of the pathogen and thus improves our ability to identify outbreak characteristics such as pathogen strain. PMID:28388665

Rod Electroretinograms Elicited by Silent Substitution Stimuli from the Light-Adapted Human Eye

PubMed Central

Maguire, John; Parry, Neil R. A.; Kremers, Jan; Kommanapalli, Deepika; Murray, Ian J.; McKeefry, Declan J.

2016-01-01

Purpose To demonstrate that silent substitution stimuli can be used to generate electroretinograms (ERGs) that effectively isolate rod photoreceptor function in humans without the need for dark adaptation, and that this approach constitutes a viable alternative to current clinical standard testing protocols. Methods Rod-isolating and non-isolating sinusoidal flicker stimuli were generated on a 4 primary light-emitting diode (LED) Ganzfeld stimulator to elicit ERGs from participants with normal and compromised rod function who had not undergone dark-adaptation. Responses were subjected to Fourier analysis, and the amplitude and phase of the fundamental were used to examine temporal frequency and retinal illuminance response characteristics. Results Electroretinograms elicited by rod-isolating silent substitution stimuli exhibit low-pass temporal frequency response characteristics with an upper response limit of 30 Hz. Responses are optimal between 5 and 8 Hz and between 10 and 100 photopic trolands (Td). There is a significant correlation between the response amplitudes obtained with the silent substitution method and current standard clinical protocols. Analysis of signal-to-noise ratios reveals significant differences between subjects with normal and compromised rod function. Conclusions Silent substitution provides an effective method for the isolation of human rod photoreceptor function in subjects with normal as well as compromised rod function when stimuli are used within appropriate parameter ranges. Translational Relevance This method of generating rod-mediated ERGs can be achieved without time-consuming periods of dark adaptation, provides improved isolation of rod- from cone-based activity, and will lead to the development of faster clinical electrophysiologic testing protocols with improved selectivity. PMID:27617180
Development of the Parent Responses to School Functioning Questionnaire.

PubMed

Barber Garcia, Brittany N; Gray, Laura S; Simons, Laura E; Logan, Deirdre E

2017-10-01

Parents play an important role in supporting school functioning in youth with chronic pain, but no validated tools exists to assess parental responses to child and adolescent pain behaviors in the school context. Such a tool would be useful in identifying targets of change to reduce pain-related school impairment. The goal of this study was to develop and preliminarily validate the Parent Responses to School Functioning Questionnaire (PRSF), a parent self-report measure of this construct. After initial expert review and pilot testing, the measure was administered to 418 parents of children (ages 6-17 years) seen for initial multidisciplinary chronic pain clinic evaluation. The final 16-item PRSF showed evidence of good internal consistency (α = .82) and 2-week test-retest reliability (intraclass correlation coefficient = .87). Criterion validity was demonstrated by significant correlations with school absence rates and overall school functioning, and construct validity was demonstrated by correlations with general parental responses to pain. Three subscales emerged capturing parents' personal distress, parents' level of distrust of the school, and parents' expectations and behaviors related to their child's management of challenging school situations. These results provide preliminary support for the PRSF as a psychometrically sound tool to assess parents' responses to child pain in the school setting. The 16-item PRSF measures parental responses to their child's chronic pain in the school context. The clinically useful measure can inform interventions aimed reducing functional disability in children with chronic pain by enhancing parents' ability to respond adaptively to child pain behaviors. Copyright © 2017 American Pain Society. Published by Elsevier Inc. All rights reserved.
Abnormal cardiovascular response to exercise in hypertension: contribution of neural factors.

PubMed

Mitchell, Jere H

2017-06-01

During both dynamic (e.g., endurance) and static (e.g., strength) exercise there are exaggerated cardiovascular responses in hypertension. This includes greater increases in blood pressure, heart rate, and efferent sympathetic nerve activity than in normal controls. Two of the known neural factors that contribute to this abnormal cardiovascular response are the exercise pressor reflex (EPR) and functional sympatholysis. The EPR originates in contracting skeletal muscle and reflexly increases sympathetic efferent nerve activity to the heart and blood vessels as well as decreases parasympathetic efferent nerve activity to the heart. These changes in autonomic nerve activity cause an increase in blood pressure, heart rate, left ventricular contractility, and vasoconstriction in the arterial tree. However, arterial vessels in the contracting skeletal muscle have a markedly diminished vasoconstrictor response. The markedly diminished vasoconstriction in contracting skeletal muscle has been termed functional sympatholysis. It has been shown in hypertension that there is an enhanced EPR, including both its mechanoreflex and metaboreflex components, and an impaired functional sympatholysis. These conditions set up a positive feedback or vicious cycle situation that causes a progressively greater decrease in the blood flow to the exercising muscle. Thus these two neural mechanisms contribute significantly to the abnormal cardiovascular response to exercise in hypertension. In addition, exercise training in hypertension decreases the enhanced EPR, including both mechanoreflex and metaboreflex function, and improves the impaired functional sympatholysis. These two changes, caused by exercise training, improve the muscle blood flow to exercising muscle and cause a more normal cardiovascular response to exercise in hypertension. Copyright © 2017 the American Physiological Society.
Aging and response conflict solution: Behavioural and functional connectivity changes

PubMed Central

Cieslik, Edna C.; Behrwind, Simone D.; Roski, Christian; Caspers, Svenja; Amunts, Katrin; Eickhoff, Simon B.

2014-01-01

Healthy aging has been found associated with less efficient response conflict solution, but the cognitive and neural mechanisms remain elusive. In a two-experiment study, we first examined the behavioural consequences of this putative age-related decline for conflicts induced by spatial stimulus–response incompatibility. We then used resting-state functional magnetic resonance imaging data from a large, independent sample of adults (n = 399; 18–85 years) to investigate age differences in functional connectivity between the nodes of a network previously found associated with incompatibility-induced response conflicts in the very same paradigm. As expected, overcoming interference from conflicting response tendencies took longer in older adults, even after accounting for potential mediator variables (general response speed and accuracy, motor speed, visuomotor coordination ability, and cognitive flexibility). Experiment 2 revealed selective age-related decreases in functional connectivity between bilateral anterior insula, pre-supplementary motor area, and right dorsolateral prefrontal cortex. Importantly, these age effects persisted after controlling for regional gray-matter atrophy assessed by voxel-based morphometry. Meta-analytic functional profiling using the BrainMap database showed these age-sensitive nodes to be more strongly linked to highly abstract cognition, as compared with the remaining network nodes, which in turn were more strongly linked to action-related processing. These findings indicate changes in interregional coupling with age among task-relevant network nodes that are not specifically associated with conflict resolution per se. Rather, our behavioural and neural data jointly suggest that healthy aging is associated with difficulties in properly activating non-dominant but relevant task schemata necessary to exert efficient cognitive control over action. PMID:24718622
Aging and response conflict solution: behavioural and functional connectivity changes.

PubMed

Langner, Robert; Cieslik, Edna C; Behrwind, Simone D; Roski, Christian; Caspers, Svenja; Amunts, Katrin; Eickhoff, Simon B

2015-01-01

Healthy aging has been found associated with less efficient response conflict solution, but the cognitive and neural mechanisms have remained elusive. In a two-experiment study, we first examined the behavioural consequences of this putative age-related decline for conflicts induced by spatial stimulus-response incompatibility. We then used resting-state functional magnetic resonance imaging data from a large, independent sample of adults (n = 399; 18-85 years) to investigate age differences in functional connectivity between the nodes of a network previously found associated with incompatibility-induced response conflicts in the very same paradigm. As expected, overcoming interference from conflicting response tendencies took longer in older adults, even after accounting for potential mediator variables (general response speed and accuracy, motor speed, visuomotor coordination ability, and cognitive flexibility). Experiment 2 revealed selective age-related decreases in functional connectivity between bilateral anterior insula, pre-supplementary motor area, and right dorsolateral prefrontal cortex. Importantly, these age effects persisted after controlling for regional grey-matter atrophy assessed by voxel-based morphometry. Meta-analytic functional profiling using the BrainMap database showed these age-sensitive nodes to be more strongly linked to highly abstract cognition, as compared with the remaining network nodes, which were more strongly linked to action-related processing. These findings indicate changes in interregional coupling with age among task-relevant network nodes that are not specifically associated with conflict resolution per se. Rather, our behavioural and neural data jointly suggest that healthy aging is associated with difficulties in properly activating non-dominant but relevant task schemata necessary to exert efficient cognitive control over action.
Functional divisions for visual processing in the central brain of flying Drosophila

PubMed Central

Weir, Peter T.; Dickinson, Michael H.

2015-01-01

Although anatomy is often the first step in assigning functions to neural structures, it is not always clear whether architecturally distinct regions of the brain correspond to operational units. Whereas neuroarchitecture remains relatively static, functional connectivity may change almost instantaneously according to behavioral context. We imaged panneuronal responses to visual stimuli in a highly conserved central brain region in the fruit fly, Drosophila, during flight. In one substructure, the fan-shaped body, automated analysis revealed three layers that were unresponsive in quiescent flies but became responsive to visual stimuli when the animal was flying. The responses of these regions to a broad suite of visual stimuli suggest that they are involved in the regulation of flight heading. To identify the cell types that underlie these responses, we imaged activity in sets of genetically defined neurons with arborizations in the targeted layers. The responses of this collection during flight also segregated into three sets, confirming the existence of three layers, and they collectively accounted for the panneuronal activity. Our results provide an atlas of flight-gated visual responses in a central brain circuit. PMID:26324910
Iterated intracochlear reflection shapes the envelopes of basilar-membrane click responses

PubMed Central

Shera, Christopher A.

2015-01-01

Multiple internal reflection of cochlear traveling waves has been argued to provide a plausible explanation for the waxing and waning and other temporal structures often exhibited by the envelopes of basilar-membrane (BM) and auditory-nerve responses to acoustic clicks. However, a recent theoretical analysis of a BM click response measured in chinchilla concludes that the waveform cannot have arisen via any equal, repetitive process, such as iterated intracochlear reflection [Wit and Bell (2015), J. Acoust. Soc. Am. 138, 94–96]. Reanalysis of the waveform contradicts this conclusion. The measured BM click response is used to derive the frequency-domain transfer function characterizing every iteration of the loop. The selfsame transfer function that yields waxing and waning of the BM click response also captures the spectral features of ear-canal stimulus-frequency otoacoustic emissions measured in the same animal, consistent with the predictions of multiple internal reflection. Small shifts in transfer-function phase simulate results at different measurement locations and reproduce the heterogeneity of BM click response envelopes observed experimentally. PMID:26723327
Functional divisions for visual processing in the central brain of flying Drosophila.

PubMed

Weir, Peter T; Dickinson, Michael H

2015-10-06

Although anatomy is often the first step in assigning functions to neural structures, it is not always clear whether architecturally distinct regions of the brain correspond to operational units. Whereas neuroarchitecture remains relatively static, functional connectivity may change almost instantaneously according to behavioral context. We imaged panneuronal responses to visual stimuli in a highly conserved central brain region in the fruit fly, Drosophila, during flight. In one substructure, the fan-shaped body, automated analysis revealed three layers that were unresponsive in quiescent flies but became responsive to visual stimuli when the animal was flying. The responses of these regions to a broad suite of visual stimuli suggest that they are involved in the regulation of flight heading. To identify the cell types that underlie these responses, we imaged activity in sets of genetically defined neurons with arborizations in the targeted layers. The responses of this collection during flight also segregated into three sets, confirming the existence of three layers, and they collectively accounted for the panneuronal activity. Our results provide an atlas of flight-gated visual responses in a central brain circuit.
Identification of visual evoked response parameters sensitive to pilot mental state

NASA Technical Reports Server (NTRS)

Zacharias, G. L.

1988-01-01

Systems analysis techniques were developed and demonstrated for modeling the electroencephalographic (EEG) steady state visual evoked response (ssVER), for use in EEG data compression and as an indicator of mental workload. The study focused on steady state frequency domain stimulation and response analysis, implemented with a sum-of-sines (SOS) stimulus generator and an off-line describing function response analyzer. Three major tasks were conducted: (1) VER related systems identification material was reviewed; (2) Software for experiment control and data analysis was developed and implemented; and (3) ssVER identification and modeling was demonstrated, via a mental loading experiment. It was found that a systems approach to ssVER functional modeling can serve as the basis for eventual development of a mental workload indicator. The review showed how transient visual evoked response (tVER) and ssVER research are related at the functional level, the software development showed how systems techniques can be used for ssVER characterization, and the pilot experiment showed how a simple model can be used to capture the basic dynamic response of the ssVER, under varying loads.
Field camera measurements of gradient and shim impulse responses using frequency sweeps.

PubMed

Vannesjo, S Johanna; Dietrich, Benjamin E; Pavan, Matteo; Brunner, David O; Wilm, Bertram J; Barmet, Christoph; Pruessmann, Klaas P

2014-08-01

Applications of dynamic shimming require high field fidelity, and characterizing the shim field dynamics is therefore necessary. Modeling the system as linear and time-invariant, the purpose of this work was to measure the impulse response function with optimal sensitivity. Frequency-swept pulses as inputs are analyzed theoretically, showing that the sweep speed is a key factor for the measurement sensitivity. By adjusting the sweep speed it is possible to achieve any prescribed noise profile in the measured system response. Impulse response functions were obtained for the third-order shim system of a 7 Tesla whole-body MR scanner. Measurements of the shim fields were done with a dynamic field camera, yielding also cross-term responses. The measured shim impulse response functions revealed system characteristics such as response bandwidth, eddy currents and specific resonances, possibly of mechanical origin. Field predictions based on the shim characterization were shown to agree well with directly measured fields, also in the cross-terms. Frequency sweeps provide a flexible tool for shim or gradient system characterization. This may prove useful for applications involving dynamic shimming by yielding accurate estimates of the shim fields and a basis for setting shim pre-emphasis. Copyright © 2013 Wiley Periodicals, Inc.
Manipulating neural activity in physiologically classified neurons: triumphs and challenges

PubMed Central

Gore, Felicity; Schwartz, Edmund C.; Salzman, C. Daniel

2015-01-01

Understanding brain function requires knowing both how neural activity encodes information and how this activity generates appropriate responses. Electrophysiological, imaging and immediate early gene immunostaining studies have been instrumental in identifying and characterizing neurons that respond to different sensory stimuli, events and motor actions. Here we highlight approaches that have manipulated the activity of physiologically classified neurons to determine their role in the generation of behavioural responses. Previous experiments have often exploited the functional architecture observed in many cortical areas, where clusters of neurons share response properties. However, many brain structures do not exhibit such functional architecture. Instead, neurons with different response properties are anatomically intermingled. Emerging genetic approaches have enabled the identification and manipulation of neurons that respond to specific stimuli despite the lack of discernable anatomical organization. These approaches have advanced understanding of the circuits mediating sensory perception, learning and memory, and the generation of behavioural responses by providing causal evidence linking neural response properties to appropriate behavioural output. However, significant challenges remain for understanding cognitive processes that are probably mediated by neurons with more complex physiological response properties. Currently available strategies may prove inadequate for determining how activity in these neurons is causally related to cognitive behaviour. PMID:26240431
34 CFR 364.57 - What functions and responsibilities may the State delegate?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 2 2010-07-01 2010-07-01 false What functions and responsibilities may the State delegate? 364.57 Section 364.57 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION STATE...
34 CFR 364.57 - What functions and responsibilities may the State delegate?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 34 Education 2 2011-07-01 2010-07-01 true What functions and responsibilities may the State delegate? 364.57 Section 364.57 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION STATE...
33 CFR 155.1045 - Response plan requirements for vessels carrying oil as a secondary cargo.

Code of Federal Regulations, 2014 CFR

2014-07-01

... must include the following functional areas and must further include information for key components within each functional area: (i) Command and control; (ii) Public information; (iii) Safety; (iv) Liaison with government agencies; (v) Spill response operations; (vi) Planning; (vii) Logistics support; and...
33 CFR 155.1045 - Response plan requirements for vessels carrying oil as a secondary cargo.

Code of Federal Regulations, 2012 CFR

2012-07-01

... must include the following functional areas and must further include information for key components within each functional area: (i) Command and control; (ii) Public information; (iii) Safety; (iv) Liaison with government agencies; (v) Spill response operations; (vi) Planning; (vii) Logistics support; and...
33 CFR 155.1045 - Response plan requirements for vessels carrying oil as a secondary cargo.

Code of Federal Regulations, 2013 CFR

2013-07-01

... must include the following functional areas and must further include information for key components within each functional area: (i) Command and control; (ii) Public information; (iii) Safety; (iv) Liaison with government agencies; (v) Spill response operations; (vi) Planning; (vii) Logistics support; and...
33 CFR 155.1045 - Response plan requirements for vessels carrying oil as a secondary cargo.

Code of Federal Regulations, 2011 CFR

2011-07-01

... must include the following functional areas and must further include information for key components within each functional area: (i) Command and control; (ii) Public information; (iii) Safety; (iv) Liaison with government agencies; (v) Spill response operations; (vi) Planning; (vii) Logistics support; and...
Calmodulin gene expression in response to mechanical wounding and Botrytis cinerea infection in tomato fruit

USDA-ARS?s Scientific Manuscript database

Calmodulin, a ubiquitous calcium sensor, plays an important role in decoding the stress-triggered intracellular calcium changes and regulates the functions of numerous target proteins involved in various physiological responses in plants. To determine the functional significance of calmodulin in fl...
The Linkage between Community Services and College Development.

ERIC Educational Resources Information Center

Mays, Sylvia A.; Vogler, Daniel E.

1985-01-01

Provides a summary of a 1984 study of the importance of 40 functions for community college resource development officers. Concludes that development officers are responsible for making friends for the college in the community, sharing this responsibility with others. Sees a role for community services personnel in development functions. (AYC)
Amplitude Frequency Response Measurement: A Simple Technique

ERIC Educational Resources Information Center

Satish, L.; Vora, S. C.

2010-01-01

A simple method is described to combine a modern function generator and a digital oscilloscope to configure a setup that can directly measure the amplitude frequency response of a system. This is achieved by synchronously triggering both instruments, with the function generator operated in the "Linear-Sweep" frequency mode, while the oscilloscope…

Groundwater response to changing water-use practices in sloping aquifers using convolution of transient response functions

USDA-ARS?s Scientific Manuscript database

This study examines the impact of a sloping base on the movement of transients through groundwater systems. Dimensionless variables and regression of model results are employed to develop functions relating the transient change in saturated thickness to the distance upgradient and downgradient from ...
24 CFR 576.404 - Conflicts of interest.

Code of Federal Regulations, 2013 CFR

2013-04-01

... section who exercises or has exercised any functions or responsibilities with respect to activities assisted under the ESG program, or who is in a position to participate in a decision-making process or gain... withdrawn from his or her functions, responsibilities or the decision-making process with respect to the...
24 CFR 1003.606 - Conflict of interest.

Code of Federal Regulations, 2013 CFR

2013-04-01

... functions or responsibilities with respect to ICDBG activities assisted under this part or who are in a position to participate in a decision-making process or gain inside information with regard to such... his or her functions or responsibilities, or from the decision-making process, with reference to the...
24 CFR 585.503 - Conflict of interest.

Code of Federal Regulations, 2012 CFR

2012-04-01

... any functions or responsibilities with respect to assisted activities, or who is in a position to participate in a decision-making process or gain inside information with regard to such activities, may obtain... withdrawn from his or her functions or responsibilities, or the decision-making process, with respect to the...
24 CFR 1003.606 - Conflict of interest.

Code of Federal Regulations, 2011 CFR

2011-04-01

... functions or responsibilities with respect to ICDBG activities assisted under this part or who are in a position to participate in a decision-making process or gain inside information with regard to such... his or her functions or responsibilities, or from the decision-making process, with reference to the...
24 CFR 576.57 - Other Federal requirements.

Code of Federal Regulations, 2011 CFR

2011-04-01

... amounts and (ii) Who exercises or has exercised any functions or responsibilities with respect to assisted activities, or (2) Who is in a position to participate in a decisionmaking process or gain inside information... be the responsible entity, and the State will assume HUD's functions with regard to the release of...
24 CFR 585.503 - Conflict of interest.

Code of Federal Regulations, 2013 CFR

2013-04-01

... any functions or responsibilities with respect to assisted activities, or who is in a position to participate in a decision-making process or gain inside information with regard to such activities, may obtain... withdrawn from his or her functions or responsibilities, or the decision-making process, with respect to the...
24 CFR 1003.606 - Conflict of interest.

Code of Federal Regulations, 2014 CFR

2014-04-01

... functions or responsibilities with respect to ICDBG activities assisted under this part or who are in a position to participate in a decision-making process or gain inside information with regard to such... his or her functions or responsibilities, or from the decision-making process, with reference to the...
24 CFR 585.503 - Conflict of interest.

Code of Federal Regulations, 2014 CFR

2014-04-01

... any functions or responsibilities with respect to assisted activities, or who is in a position to participate in a decision-making process or gain inside information with regard to such activities, may obtain... withdrawn from his or her functions or responsibilities, or the decision-making process, with respect to the...
24 CFR 1003.606 - Conflict of interest.

Code of Federal Regulations, 2012 CFR

2012-04-01

... functions or responsibilities with respect to ICDBG activities assisted under this part or who are in a position to participate in a decision-making process or gain inside information with regard to such... his or her functions or responsibilities, or from the decision-making process, with reference to the...
24 CFR 585.503 - Conflict of interest.

Code of Federal Regulations, 2011 CFR

2011-04-01

... any functions or responsibilities with respect to assisted activities, or who is in a position to participate in a decision-making process or gain inside information with regard to such activities, may obtain... withdrawn from his or her functions or responsibilities, or the decision-making process, with respect to the...
Helping as a Function of Empathic Responses and Sociopathy.

ERIC Educational Resources Information Center

Marks, Edward L.; And Others

1982-01-01

Investigated helping as a function of empathic anxiety (anxiety in response to modeled distress) and individual differences in sociopathic tendencies. Results indicated modeled distress produces increases in anxiety which are positively associated with helping and sociopathic individuals are less likely to help than are nonsociopathic individuals.…
Correlates of endothelial function and the peak systolic blood pressure response to a graded maximal exercise test.

PubMed

Olson, Kayla M; Augeri, Amanda L; Seip, Richard L; Tsongalis, Gregory J; Thompson, Paul D; Pescatello, Linda S

2012-05-01

An elevated systolic blood pressure (SBP) response to a graded maximal exercise stress test (GEST) may be a predictor of endothelial dysfunction and hypertension. We examined relationships among the GEST peak SBP response and indicators of endothelial function. Men (n=48, 43.7±1.4 yr) with high BP (145.1±1.5/85.5±1.1 mmHg) completed a GEST. Peak SBP was the highest SBP achieved during the GEST. Blood samples were taken for fasting glucose and insulin, nitric oxide (NO), and DNA. Endothelial nitric oxide synthase (NOS3, rs2070744) -786 T>C genotyping was determined by PCR. NOS3 genotypes were combined using a dominant model [TT (n=24); TC/CC (n=24)]. Brachial artery reactivity (BAR) was determined via ultrasound before, 1 min, and 3 min post occlusion and calculated as % change. Analysis of variance (ANOVA) tested changes in the peak SBP GEST response by NOS3 genotype. Multiple variable regression analyses examined relationships among the GEST peak SBP response and measures of endothelial function. %BAR change at 1 min (r(2)=0.093, p=0.020), glucose (r(2)=0.062, p=0.014), NOS3 -786 T>C (r(2)=0.040, p=0.024), NO (r(2)=0.037, p=0.064), and age (r(2)=0.009, p=0.014) explained 24.1% of the GEST peak SBP response (p=0.043). The GEST peak SBP change from baseline was 11.1±5.0 mmHg higher among those with the NOS3 C allele (92.4 mmHg+3.8) than the NOS3 TT genotype (81.3 mmHg+3.2) (p=0.03). Indicators of endothelial function appear to explain a clinically significant portion of the GEST peak SBP response. Further investigation is needed to unravel the mechanisms by which endothelial function influences the GEST peak SBP response. Published by Elsevier Ireland Ltd.
The effect of streptozotocin-induced diabetes on the EDHF-type relaxation and cardiac function in rats.

PubMed

Absi, Mais; Oso, Hani; Khattab, Marwan

2013-07-01

The endothelium-derived hyperpolarizing factor (EDHF) response is a critical for the functioning of small blood vessels. We investigated the effect of streptozotocin-induced diabetes on the EDHF response and its possible role in the regulation of cardiac function. The vasorelaxant response to ACh- or NS309- (direct opener endothelial small- (SKCa)- and intermediate-conductance (IKCa) calcium-activated potassium channels; main components of EDHF response) were measured in pressurized mesenteric arteries (diameter 300-350 μm). The response to 1 μM ACh was reduced in diabetes (84.8 ± 2.8% control vs 22.5 ± 5.8% diabetics; n ⩾ 8; P < 0.001). NS309 (1 μM) relaxations were also decreased in diabetic arteries (78.5 ± 8.7% control vs 32.1 ± 5.8% diabetics; n ⩾ 5; P < 0.001). SKCa and IKCa-mediated EDHF relaxations in response ACh or NS309 were also significantly reduced by diabetes. Ruthenium red, RuR, a blocker of TRP channels, strongly depress the response to ACh and NS309 in control and diabetic arteries. RuR decreased SKCa and IKCa-mediated EDHF vasodilatation in response to NS309 but not to ACh. An elevation in systolic blood pressure was observed in diabetic animals. ECG recording of control hearts showed shortening of PR interval. RuR reduced PR interval and R wave amplitude in diabetic hearts. In conclusion, the reduced EDHF-type relaxations in STZ-induced diabetes is due impairment of KCa channels function. TRP channels possibly contribute to EDHF vasodilatation via direct opening of endothelial KCa. It is possible that EDHF and TRP channels contribute to the regulation of cardiac function and therefore can be considered as therapeutic targets to improve cardiovascular complications of diabetes.
Impact of cardiac resynchronization therapy on inflammatory biomarkers and cardiac remodeling: The paradox of functional and echocardiographic response.

PubMed

Almeida-Morais, Luís; Abreu, Ana; Oliveira, Mário; Silva Cunha, Pedro; Rodrigues, Inês; Portugal, Guilherme; Rio, Pedro; Soares, Rui; Mota Carmo, Miguel; Cruz Ferreira, Rui

2018-02-01

Response to cardiac resynchronization therapy (CRT) can currently be assessed by clinical or echocardiographic criteria, and there is no strong evidence supporting the use of one rather than the other. Reductions in B-type natriuretic peptide (BNP) and C-reactive protein (CRP) have been shown to be associated with CRT response. This study aims to assess variation in BNP and CRP six months after CRT and to correlate this variation with criteria of functional and echocardiographic response. Patients undergoing CRT were prospectively enrolled between 2011 and 2014. CRT response was defined by echocardiography (15% reduction in left ventricular end-systolic volume) and by cardiopulmonary exercise testing (10% increase in peak oxygen consumption) from baseline to six months after device implantation. A total of 115 patients were enrolled (68.7% male, mean age 68.6±10.5 years). Echocardiographic response was seen in 51.4% and 59.2% were functional responders. There was no statistical correlation between the two. Functional response was associated with a significantly greater reduction in BNP (-167.6±264.1 vs. -24.9±269.4 pg/ml; p=0.044) and CRP levels (-1.6±4.4 vs. 2.4±9.9 mg/l; p=0.04). Nonetheless, a non-significant reduction in BNP and CRP was observed in echocardiographic responders (BNP -144.7±260.2 vs. -66.1±538.2 pg/ml and CRP -7.1±24.3 vs. 0.8±10.3 mg/l; p>0.05). An increase in exercise capacity after CRT implantation is associated with improvement in myocardial remodeling and inflammatory biomarkers. This finding highlights the importance of improvement in functional capacity after CRT implantation, not commonly considered a criterion of CRT response. Copyright © 2018 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.
The effect of streptozotocin-induced diabetes on the EDHF-type relaxation and cardiac function in rats

PubMed Central

Absi, Mais; Oso, Hani; Khattab, Marwan

2012-01-01

The endothelium-derived hyperpolarizing factor (EDHF) response is a critical for the functioning of small blood vessels. We investigated the effect of streptozotocin-induced diabetes on the EDHF response and its possible role in the regulation of cardiac function. The vasorelaxant response to ACh- or NS309- (direct opener endothelial small- (SKCa)- and intermediate-conductance (IKCa) calcium-activated potassium channels; main components of EDHF response) were measured in pressurized mesenteric arteries (diameter 300–350 μm). The response to 1 μM ACh was reduced in diabetes (84.8 ± 2.8% control vs 22.5 ± 5.8% diabetics; n ⩾ 8; P < 0.001). NS309 (1 μM) relaxations were also decreased in diabetic arteries (78.5 ± 8.7% control vs 32.1 ± 5.8% diabetics; n ⩾ 5; P < 0.001). SKCa and IKCa-mediated EDHF relaxations in response ACh or NS309 were also significantly reduced by diabetes. Ruthenium red, RuR, a blocker of TRP channels, strongly depress the response to ACh and NS309 in control and diabetic arteries. RuR decreased SKCa and IKCa-mediated EDHF vasodilatation in response to NS309 but not to ACh. An elevation in systolic blood pressure was observed in diabetic animals. ECG recording of control hearts showed shortening of PR interval. RuR reduced PR interval and R wave amplitude in diabetic hearts. In conclusion, the reduced EDHF-type relaxations in STZ-induced diabetes is due impairment of KCa channels function. TRP channels possibly contribute to EDHF vasodilatation via direct opening of endothelial KCa. It is possible that EDHF and TRP channels contribute to the regulation of cardiac function and therefore can be considered as therapeutic targets to improve cardiovascular complications of diabetes. PMID:25685443
Occupational Safety and Health System for Workers Engaged in Emergency Response Operations in the USA.

PubMed

Toyoda, Hiroyuki; Kubo, Tatsuhiko; Mori, Koji

2016-12-03

To study the occupational safety and health systems used for emergency response workers in the USA, we performed interviews with related federal agencies and conducted research on related studies. We visited the Federal Emergency Management Agency (FEMA) and National Institute for Occupational Safety and Health (NIOSH) in the USA and performed interviews with their managers on the agencies' roles in the national emergency response system. We also obtained information prepared for our visit from the USA's Occupational Safety and Health Administration (OSHA). In addition, we conducted research on related studies and information on the website of the agencies. We found that the USA had an established emergency response system based on their National Incident Management System (NIMS). This enabled several organizations to respond to emergencies cooperatively using a National Response Framework (NRF) that clarifies the roles and cooperative functions of each federal agency. The core system in NIMS was the Incident Command System (ICS), within which a Safety Officer was positioned as one of the command staff supporting the commander. All ICS staff were required to complete a training program specific to their position; in addition, the Safety Officer was required to have experience. The All-Hazards model was commonly used in the emergency response system. We found that FEMA coordinated support functions, and OSHA and NIOSH, which had specific functions to protect workers, worked cooperatively under NRF. These agencies employed certified industrial hygienists that play a professional role in safety and health. NIOSH recently executed support activities during disasters and other emergencies. The USA's emergency response system is characterized by functions that protect the lives and health of emergency response workers. Trained and experienced human resources support system effectiveness. The findings provided valuable information that could be used to improve the occupational safety and health function in the Japanese system.
42 CFR 493.1413 - Standard; Technical consultant responsibilities.

Code of Federal Regulations, 2013 CFR

2013-10-01

... consultant responsibilities. The technical consultant is responsible for the technical and scientific... of performance of instrument maintenance and function checks; (v) Assessment of test performance...
42 CFR 493.1413 - Standard; Technical consultant responsibilities.

Code of Federal Regulations, 2014 CFR

2014-10-01

... consultant responsibilities. The technical consultant is responsible for the technical and scientific... of performance of instrument maintenance and function checks; (v) Assessment of test performance...
Left dorsal premotor cortex and supramarginal gyrus complement each other during rapid action reprogramming

PubMed Central

Hartwigsen, Gesa; Bestmann, Sven; Ward, Nick S.; Woerbel, Saskia; Mastroeni, Claudia; Granert, Oliver; Siebner, Hartwig R.

2013-01-01

The ability to discard a prepared action plan in favor of an alternative action is critical when facing sudden environmental changes. We tested whether the functional contribution of left supramarginal gyrus (SMG) during action reprogramming depends on the functional integrity of left dorsal premotor cortex (PMd). Adopting a dual-site repetitive transcranial magnetic stimulation (rTMS) strategy, we first transiently disrupted PMd with “offline” 1Hz rTMS and then applied focal “online” rTMS to SMG whilst human subjects performed a spatially-precued reaction time task. Effective online rTMS of SMG but not sham rTMS of SMG increased errors when subjects had to reprogram their action in response to an invalid precue regardless of the type of preceding offline rTMS. This suggests that left SMG primarily contributes to the online updating of actions by suppressing invalidly prepared responses. Online rTMS of SMG additionally increased reaction times for correct responses in invalidly-precued trials, but only after offline rTMS of PMd. We infer that offline rTMS caused an additional dysfunction of PMd which increased the functional relevance of SMG for rapid activation of the correct response, and sensitized SMG to the disruptive effects of online rTMS. These results not only provide causal evidence that left PMd and SMG jointly contribute to action reprogramming, but also that the respective functional weight of these areas can be rapidly redistributed. This mechanism might constitute a generic feature of functional networks that allows for rapid functional compensation in response to focal dysfunctions. PMID:23152600

Gain-of-function human STAT1 mutations impair IL-17 immunity and underlie chronic mucocutaneous candidiasis

PubMed Central

Liu, Luyan; Okada, Satoshi; Kong, Xiao-Fei; Kreins, Alexandra Y.; Cypowyj, Sophie; Abhyankar, Avinash; Toubiana, Julie; Itan, Yuval; Audry, Magali; Nitschke, Patrick; Masson, Cécile; Toth, Beata; Flatot, Jérome; Migaud, Mélanie; Chrabieh, Maya; Kochetkov, Tatiana; Bolze, Alexandre; Borghesi, Alessandro; Toulon, Antoine; Hiller, Julia; Eyerich, Stefanie; Eyerich, Kilian; Gulácsy, Vera; Chernyshova, Ludmyla; Chernyshov, Viktor; Bondarenko, Anastasia; María Cortés Grimaldo, Rosa; Blancas-Galicia, Lizbeth; Madrigal Beas, Ileana Maria; Roesler, Joachim; Magdorf, Klaus; Engelhard, Dan; Thumerelle, Caroline; Burgel, Pierre-Régis; Hoernes, Miriam; Drexel, Barbara; Seger, Reinhard; Kusuma, Theresia; Jansson, Annette F.; Sawalle-Belohradsky, Julie; Belohradsky, Bernd; Jouanguy, Emmanuelle; Bustamante, Jacinta; Bué, Mélanie; Karin, Nathan; Wildbaum, Gizi; Bodemer, Christine; Lortholary, Olivier; Fischer, Alain; Blanche, Stéphane; Al-Muhsen, Saleh; Reichenbach, Janine; Kobayashi, Masao; Rosales, Francisco Espinosa; Lozano, Carlos Torres; Kilic, Sara Sebnem; Oleastro, Matias; Etzioni, Amos; Traidl-Hoffmann, Claudia; Renner, Ellen D.; Abel, Laurent; Picard, Capucine; Maródi, László; Boisson-Dupuis, Stéphanie

2011-01-01

Chronic mucocutaneous candidiasis disease (CMCD) may be caused by autosomal dominant (AD) IL-17F deficiency or autosomal recessive (AR) IL-17RA deficiency. Here, using whole-exome sequencing, we identified heterozygous germline mutations in STAT1 in 47 patients from 20 kindreds with AD CMCD. Previously described heterozygous STAT1 mutant alleles are loss-of-function and cause AD predisposition to mycobacterial disease caused by impaired STAT1-dependent cellular responses to IFN-γ. Other loss-of-function STAT1 alleles cause AR predisposition to intracellular bacterial and viral diseases, caused by impaired STAT1-dependent responses to IFN-α/β, IFN-γ, IFN-λ, and IL-27. In contrast, the 12 AD CMCD-inducing STAT1 mutant alleles described here are gain-of-function and increase STAT1-dependent cellular responses to these cytokines, and to cytokines that predominantly activate STAT3, such as IL-6 and IL-21. All of these mutations affect the coiled-coil domain and impair the nuclear dephosphorylation of activated STAT1, accounting for their gain-of-function and dominance. Stronger cellular responses to the STAT1-dependent IL-17 inhibitors IFN-α/β, IFN-γ, and IL-27, and stronger STAT1 activation in response to the STAT3-dependent IL-17 inducers IL-6 and IL-21, hinder the development of T cells producing IL-17A, IL-17F, and IL-22. Gain-of-function STAT1 alleles therefore cause AD CMCD by impairing IL-17 immunity. PMID:21727188
Effects of childhood trauma on left inferior frontal gyrus function during response inhibition across psychotic disorders.

PubMed

Quidé, Y; O'Reilly, N; Watkeys, O J; Carr, V J; Green, M J

2018-07-01

Childhood trauma is a risk factor for psychosis. Deficits in response inhibition are common to psychosis and trauma-exposed populations, and associated brain functions may be affected by trauma exposure in psychotic disorders. We aimed to identify the influence of trauma-exposure on brain activation and functional connectivity during a response inhibition task. We used functional magnetic resonance imaging to examine brain function within regions-of-interest [left and right inferior frontal gyrus (IFG), right dorsolateral prefrontal cortex, right supplementary motor area, right inferior parietal lobule and dorsal anterior cingulate cortex], during the performance of a Go/No-Go Flanker task, in 112 clinical cases with psychotic disorders and 53 healthy controls (HCs). Among the participants, 71 clinical cases and 21 HCs reported significant levels of childhood trauma exposure, while 41 clinical cases and 32 HCs did not. In the absence of effects on response inhibition performance, childhood trauma exposure was associated with increased activation in the left IFG, and increased connectivity between the left IFG seed region and the cerebellum and calcarine sulcus, in both cases and healthy individuals. There was no main effect of psychosis, and no trauma-by-psychosis interaction for any other region-of-interest. Within the clinical sample, the effects of trauma-exposure on the left IFG activation were mediated by symptom severity. Trauma-related increases in activation of the left IFG were not associated with performance differences, or dependent on clinical diagnostic status; increased IFG functionality may represent a compensatory (overactivation) mechanism required to exert adequate inhibitory control of the motor response.
Aging and the interaction of sensory cortical function and structure.

PubMed

Peiffer, Ann M; Hugenschmidt, Christina E; Maldjian, Joseph A; Casanova, Ramon; Srikanth, Ryali; Hayasaka, Satoru; Burdette, Jonathan H; Kraft, Robert A; Laurienti, Paul J

2009-01-01

Even the healthiest older adults experience changes in cognitive and sensory function. Studies show that older adults have reduced neural responses to sensory information. However, it is well known that sensory systems do not act in isolation but function cooperatively to either enhance or suppress neural responses to individual environmental stimuli. Very little research has been dedicated to understanding how aging affects the interactions between sensory systems, especially cross-modal deactivations or the ability of one sensory system (e.g., audition) to suppress the neural responses in another sensory system cortex (e.g., vision). Such cross-modal interactions have been implicated in attentional shifts between sensory modalities and could account for increased distractibility in older adults. To assess age-related changes in cross-modal deactivations, functional MRI studies were performed in 61 adults between 18 and 80 years old during simple auditory and visual discrimination tasks. Results within visual cortex confirmed previous findings of decreased responses to visual stimuli for older adults. Age-related changes in the visual cortical response to auditory stimuli were, however, much more complex and suggested an alteration with age in the functional interactions between the senses. Ventral visual cortical regions exhibited cross-modal deactivations in younger but not older adults, whereas more dorsal aspects of visual cortex were suppressed in older but not younger adults. These differences in deactivation also remained after adjusting for age-related reductions in brain volume of sensory cortex. Thus, functional differences in cortical activity between older and younger adults cannot solely be accounted for by differences in gray matter volume. (c) 2007 Wiley-Liss, Inc.
Identifying functional groups for response to disturbance in an abandoned pasture

NASA Astrophysics Data System (ADS)

Lavorel, Sandra; Touzard, Blaise; Lebreton, Jean-Dominique; Clément, Bernard

1998-06-01

In an abandoned pasture in Brittany, we compared artificial small-scale disturbances to natural disturbances by wild boar and undisturbed vegetation. We developed a multivariate statistical approach which analyses how species biological attributes explain the response of community composition to disturbances. This technique, which reconciles the inductive and deductive approaches for functional classifications, identifies groups of species with similar responses to disturbance and characterizes their biological profiles. After 5 months of recolonization, artificial disturbances had a greater species richness than undisturbed vegetation as a result of recruitment of new species without the exclusion of pre-existing matrix species. Species morphology, described by canopy structure, canopy height and lateral spread, explained a large part (16 %) of community response to disturbance. Regeneration strategies, described by life history, seed mass, dispersal agent, dormancy and the existence of vegetative multiplication, explained a smaller part of community response to disturbance (8 %). Artificial disturbances were characterized by therophyte and compact rosettes with moderately dormant seeds, including a number of Asteraceae and other early successional species. Natural disturbances were colonized by leafy guerrilla species without seed dormancy. Few species were tightly related to undisturbed vegetation and were essentially grasses with a phalanx rosette morphology. The functional classification obtained is consistent with the classification of the community into fugitives, regenerators and persistors. These groups are structured according to Grubb's model for temperate grasslands, with regenerators and persistors in the matrix and fugitives taking advantage of gaps open by small-scale disturbances. The conjunction of functional diversity and species diversity within functional groups is the key to resilience to disturbance, an important ecosystem function.
Mouse neutrophils lacking lamin B receptor expression exhibit aberrant development and lack critical functional responses

PubMed Central

Gaines, Peter; Tien, Chiung W.; Olins, Ada L.; Olins, Donald E.; Shultz, Leonard D.; Carney, Lisa; Berliner, Nancy

2008-01-01

Objective The capacity of neutrophils to eradicate bacterial infections is dependent on normal development and the activation of functional responses, which include chemotaxis and the generation of oxygen radicals during the respiratory burst. A unique feature of the neutrophil is its highly lobulated nucleus, which is thought to facilitate chemotaxis but may also play a role in other critical neutrophil functions. Nuclear lobulation is dependent on the expression of the inner nuclear envelope protein, the lamin B receptor (LBR), mutations of which cause hypolobulated neutrophil nuclei in human Pelger-Huët anomaly (PHA) and the "ichthyosis" (ic) phenotype in mice. In this study we have investigated roles for LBR in mediating neutrophil development and the activation of multiple neutrophil functions, including chemotaxis and the respiratory burst. Materials and Methods A progenitor EML cell line was generated from an ic/ic mouse, and derived cells that lacked LBR expression were induced to mature neutrophils and then examined for abnormal morphology and functional responses. Results Neutrophils derived from EML-ic/ic cells exhibited nuclear hypolobulation identical to that observed in ichthyosis mice. The ic/ic neutrophils also displayed abnormal chemotaxis, supporting the notion that nuclear segmentation augments neutrophil extravasation. Furthermore, promyelocytic forms of ic/ic cells displayed decreased proliferative responses and produced a deficient respiratory burst upon terminal maturation. Conclusions Our studies of promyelocytes that lack LBR expression have identified roles for LBR in regulating not only the morphologic maturation of the neutrophil nucleus but also proliferative and functional responses that are critical to innate immunity. PMID:18550262
Comparing light sensitivity, linearity and step response of electronic cameras for ophthalmology.

PubMed

Kopp, O; Markert, S; Tornow, R P

2002-01-01

To develop and test a procedure to measure and compare light sensitivity, linearity and step response of electronic cameras. The pixel value (PV) of digitized images as a function of light intensity (I) was measured. The sensitivity was calculated from the slope of the P(I) function, the linearity was estimated from the correlation coefficient of this function. To measure the step response, a short sequence of images was acquired. During acquisition, a light source was switched on and off using a fast shutter. The resulting PV was calculated for each video field of the sequence. A CCD camera optimized for the near-infrared (IR) spectrum showed the highest sensitivity for both, visible and IR light. There are little differences in linearity. The step response depends on the procedure of integration and read out.
Estimating neural response functions from fMRI

PubMed Central

Kumar, Sukhbinder; Penny, William

2014-01-01

This paper proposes a methodology for estimating Neural Response Functions (NRFs) from fMRI data. These NRFs describe non-linear relationships between experimental stimuli and neuronal population responses. The method is based on a two-stage model comprising an NRF and a Hemodynamic Response Function (HRF) that are simultaneously fitted to fMRI data using a Bayesian optimization algorithm. This algorithm also produces a model evidence score, providing a formal model comparison method for evaluating alternative NRFs. The HRF is characterized using previously established “Balloon” and BOLD signal models. We illustrate the method with two example applications based on fMRI studies of the auditory system. In the first, we estimate the time constants of repetition suppression and facilitation, and in the second we estimate the parameters of population receptive fields in a tonotopic mapping study. PMID:24847246
Black light - How sensors filter spectral variation of the illuminant

NASA Technical Reports Server (NTRS)

Brainard, David H.; Wandell, Brian A.; Cowan, William B.

1989-01-01

Visual sensor responses may be used to classify objects on the basis of their surface reflectance functions. In a color image, the image data are represented as a vector of sensor responses at each point in the image. This vector depends both on the surface reflectance functions and on the spectral power distribution of the ambient illumination. Algorithms designed to classify objects on the basis of their surface reflectance functions typically attempt to overcome the dependence of the sensor responses on the illuminant by integrating sensor data collected from multiple surfaces. In machine vision applications, it is shown that it is often possible to design the sensor spectral responsivities so that the vector direction of the sensor responses does not depend upon the illuminant. The conditions under which this is possible are given and an illustrative calculation is performed. In biological systems, where the sensor responsivities are fixed, it is shown that some changes in the illumination cause no change in the sensor responses. Such changes in illuminant are called black illuminants. It is possible to express any illuminant as the sum of two unique components. One component is a black illuminant. The second component is called the visible component. The visible component of an illuminant completely characterizes the effect of the illuminant on the vector of sensor responses.
Intracranial mapping of auditory perception: event-related responses and electrocortical stimulation.

PubMed

Sinai, A; Crone, N E; Wied, H M; Franaszczuk, P J; Miglioretti, D; Boatman-Reich, D

2009-01-01

We compared intracranial recordings of auditory event-related responses with electrocortical stimulation mapping (ESM) to determine their functional relationship. Intracranial recordings and ESM were performed, using speech and tones, in adult epilepsy patients with subdural electrodes implanted over lateral left cortex. Evoked N1 responses and induced spectral power changes were obtained by trial averaging and time-frequency analysis. ESM impaired perception and comprehension of speech, not tones, at electrode sites in the posterior temporal lobe. There was high spatial concordance between ESM sites critical for speech perception and the largest spectral power (100% concordance) and N1 (83%) responses to speech. N1 responses showed good sensitivity (0.75) and specificity (0.82), but poor positive predictive value (0.32). Conversely, increased high-frequency power (>60Hz) showed high specificity (0.98), but poorer sensitivity (0.67) and positive predictive value (0.67). Stimulus-related differences were observed in the spatial-temporal patterns of event-related responses. Intracranial auditory event-related responses to speech were associated with cortical sites critical for auditory perception and comprehension of speech. These results suggest that the distribution and magnitude of intracranial auditory event-related responses to speech reflect the functional significance of the underlying cortical regions and may be useful for pre-surgical functional mapping.
Intracranial mapping of auditory perception: Event-related responses and electrocortical stimulation

PubMed Central

Sinai, A.; Crone, N.E.; Wied, H.M.; Franaszczuk, P.J.; Miglioretti, D.; Boatman-Reich, D.

2010-01-01

Objective We compared intracranial recordings of auditory event-related responses with electrocortical stimulation mapping (ESM) to determine their functional relationship. Methods Intracranial recordings and ESM were performed, using speech and tones, in adult epilepsy patients with subdural electrodes implanted over lateral left cortex. Evoked N1 responses and induced spectral power changes were obtained by trial averaging and time-frequency analysis. Results ESM impaired perception and comprehension of speech, not tones, at electrode sites in the posterior temporal lobe. There was high spatial concordance between ESM sites critical for speech perception and the largest spectral power (100% concordance) and N1 (83%) responses to speech. N1 responses showed good sensitivity (0.75) and specificity (0.82), but poor positive predictive value (0.32). Conversely, increased high-frequency power (>60 Hz) showed high specificity (0.98), but poorer sensitivity (0.67) and positive predictive value (0.67). Stimulus-related differences were observed in the spatial-temporal patterns of event-related responses. Conclusions Intracranial auditory event-related responses to speech were associated with cortical sites critical for auditory perception and comprehension of speech. Significance These results suggest that the distribution and magnitude of intracranial auditory event-related responses to speech reflect the functional significance of the underlying cortical regions and may be useful for pre-surgical functional mapping. PMID:19070540
Contributions of structural connectivity and cerebrovascular parameters to functional magnetic resonance imaging signals in mice at rest and during sensory paw stimulation.

PubMed

Schroeter, Aileen; Grandjean, Joanes; Schlegel, Felix; Saab, Bechara J; Rudin, Markus

2017-07-01

Previously, we reported widespread bilateral increases in stimulus-evoked functional magnetic resonance imaging signals in mouse brain to unilateral sensory paw stimulation. We attributed the pattern to arousal-related cardiovascular changes overruling cerebral autoregulation thereby masking specific signal changes elicited by local neuronal activity. To rule out the possibility that interhemispheric neuronal communication might contribute to bilateral functional magnetic resonance imaging responses, we compared stimulus-evoked functional magnetic resonance imaging responses to unilateral hindpaw stimulation in acallosal I/LnJ, C57BL/6, and BALB/c mice. We found bilateral blood-oxygenation-level dependent signal changes in all three strains, ruling out a dominant contribution of transcallosal communication as reason for bilaterality. Analysis of functional connectivity derived from resting-state functional magnetic resonance imaging, revealed that bilateral cortical functional connectivity is largely abolished in I/LnJ animals. Cortical functional connectivity in all strains correlated with structural connectivity in corpus callosum as revealed by diffusion tensor imaging. Given the profound influence of systemic hemodynamics on stimulus-evoked functional magnetic resonance imaging outcomes, we evaluated whether functional connectivity data might be affected by cerebrovascular parameters, i.e. baseline cerebral blood volume, vascular reactivity, and reserve. We found that effects of cerebral hemodynamics on functional connectivity are largely outweighed by dominating contributions of structural connectivity. In contrast, contributions of transcallosal interhemispheric communication to the occurrence of ipsilateral functional magnetic resonance imaging response of equal amplitude to unilateral stimuli seem negligible.
Assessing Mand Topography Preference When Developing a Functional Communication Training Intervention.

PubMed

Kunnavatana, S Shanun; Wolfe, Katie; Aguilar, Alexandra N

2018-05-01

Functional communication training (FCT) is a common function-based behavioral intervention used to decrease problem behavior by teaching an alternative communication response. Therapists often arbitrarily select the topography of the alternative response, which may influence long-term effectiveness of the intervention. Assessing individual mand topography preference may increase treatment effectiveness and promote self-determination in the development of interventions. This study sought to reduce arbitrary selection of FCT mand topography by determining preference during response training and acquisition for two adults with autism who had no functional communication skills. Both participants demonstrated a clear preference for one mand topography during choice probes, and the preferred topography was then reinforced during FCT to reduce problem behavior and increase independent communication. The implications of the results for future research on mand selection during FCT are discussed.
In Search of a Visual-cortical Describing Function: a Summary of Work in Progress

NASA Technical Reports Server (NTRS)

Junker, A. M.; Peio, K. J.

1984-01-01

The thrust of the present work is to explore the utility of using a sum of sinusoids (seven or more) to obtain an evoked response and, furthermore, to see if the response is sensitive to changes in cognitive processing. Within the field of automatic control system technology, a mathematical input/output relationship for a sinusoidally stimulated nonlinear system is defined as describing function. Applying this technology, sum of sines inputs to yield describing functions for the visual-cortical response have been designed. What follows is a description of the method used to obtain visual-cortical describing functions. A number of measurement system redesigns were necessary to achieve the desired frequency resolution. Results that guided and came out of the redesigns are presented. Preliminary results of stimulus parameter effects (average intensity and depth of modulation) are also shown.
A Noise Level Prediction Method Based on Electro-Mechanical Frequency Response Function for Capacitors

PubMed Central

Zhu, Lingyu; Ji, Shengchang; Shen, Qi; Liu, Yuan; Li, Jinyu; Liu, Hao

2013-01-01

The capacitors in high-voltage direct-current (HVDC) converter stations radiate a lot of audible noise which can reach higher than 100 dB. The existing noise level prediction methods are not satisfying enough. In this paper, a new noise level prediction method is proposed based on a frequency response function considering both electrical and mechanical characteristics of capacitors. The electro-mechanical frequency response function (EMFRF) is defined as the frequency domain quotient of the vibration response and the squared capacitor voltage, and it is obtained from impulse current experiment. Under given excitations, the vibration response of the capacitor tank is the product of EMFRF and the square of the given capacitor voltage in frequency domain, and the radiated audible noise is calculated by structure acoustic coupling formulas. The noise level under the same excitations is also measured in laboratory, and the results are compared with the prediction. The comparison proves that the noise prediction method is effective. PMID:24349105
Autonomic control of adrenal function.

PubMed Central

Edwards, A V; Jones, C T

1993-01-01

Recent studies of adrenal function in conscious calves are reviewed. These have involved collecting the whole of the adrenal effluent blood from the right adrenal gland at intervals and, where necessary, prior functional hypophysectomy by destruction of the pituitary stalk under general halothane anaesthesia 3 d previously. The adrenal medulla was found to release numerous neuropeptides, in addition to catecholamines, in response to stimulation of the peripheral end of the right splanchnic nerve, which was carried out below behavioural threshold. Many of these responses were enhanced by stimulating intermittently at a relatively high frequency. Intra-aortic infusions of a relatively low dose of acetylcholine (4.5 nmol min-1 kg-1) elicited similar responses. In the adrenal cortex, agonists which either potentiated the steroidogenic response to ACTH or exerted a direct steroidogenic action included VIP, CGRP, CRF and ACh acting via muscarinic receptors. Stimulation of the peripheral end of the right splanchnic nerve strongly potentiated the steroidogenic response to ACTH and there is compelling evidence that the innervation normally plays an important part in cortisol secretion. PMID:8300417
Response Surface Modeling Using Multivariate Orthogonal Functions

NASA Technical Reports Server (NTRS)

Morelli, Eugene A.; DeLoach, Richard

2001-01-01

A nonlinear modeling technique was used to characterize response surfaces for non-dimensional longitudinal aerodynamic force and moment coefficients, based on wind tunnel data from a commercial jet transport model. Data were collected using two experimental procedures - one based on modem design of experiments (MDOE), and one using a classical one factor at a time (OFAT) approach. The nonlinear modeling technique used multivariate orthogonal functions generated from the independent variable data as modeling functions in a least squares context to characterize the response surfaces. Model terms were selected automatically using a prediction error metric. Prediction error bounds computed from the modeling data alone were found to be- a good measure of actual prediction error for prediction points within the inference space. Root-mean-square model fit error and prediction error were less than 4 percent of the mean response value in all cases. Efficacy and prediction performance of the response surface models identified from both MDOE and OFAT experiments were investigated.
The Role of Common Motor Responses in Stimulus Categorization by Preschool Children

PubMed Central

Mahoney, Amanda M; Miguel, Caio F; Ahearn, William H; Bell, Julianne

2011-01-01

The purpose of this study was to assess the role of common motor responses as the “speaker” behavior on stimulus class formation, and the emergence of functional classes. Experiment 1 examined whether training one motor response to a set of three stimuli and a second motor response to another set of three stimuli would result in correct category-sort responses for 5 typically developing preschool children. Three of the children passed the categorization tests. Experiment 2 examined whether the classes formed in Experiment 1 were functional classes, and whether participants who did not pass categorization tests in Experiment 1 would do so following common vocal tact training. The 2 participants who failed categorization tests in Experiment 1 passed these tests in Experiment 2, although none of the participants passed the tests for functional classes. The results of the current study did not unequivocally support the naming hypothesis. Future research should therefore evaluate other possible sources of control that aid in stimulus categorization. PMID:21541124
Mixed-effects Gaussian process functional regression models with application to dose-response curve prediction.

PubMed

Shi, J Q; Wang, B; Will, E J; West, R M

2012-11-20

We propose a new semiparametric model for functional regression analysis, combining a parametric mixed-effects model with a nonparametric Gaussian process regression model, namely a mixed-effects Gaussian process functional regression model. The parametric component can provide explanatory information between the response and the covariates, whereas the nonparametric component can add nonlinearity. We can model the mean and covariance structures simultaneously, combining the information borrowed from other subjects with the information collected from each individual subject. We apply the model to dose-response curves that describe changes in the responses of subjects for differing levels of the dose of a drug or agent and have a wide application in many areas. We illustrate the method for the management of renal anaemia. An individual dose-response curve is improved when more information is included by this mechanism from the subject/patient over time, enabling a patient-specific treatment regime. Copyright © 2012 John Wiley & Sons, Ltd.
Bicarbonate Induced Redox Proteome Changes in Arabidopsis Suspension Cells.

PubMed

Yin, Zepeng; Balmant, Kelly; Geng, Sisi; Zhu, Ning; Zhang, Tong; Dufresne, Craig; Dai, Shaojun; Chen, Sixue

2017-01-01

Climate change as a result of increasing atmospheric CO 2 affects plant growth and productivity. CO 2 is not only a carbon donor for photosynthesis but also an environmental signal that can perturb cellular redox homeostasis and lead to modifications of redox-sensitive proteins. Although redox regulation of protein functions has emerged as an important mechanism in several biological processes, protein redox modifications and how they function in plant CO 2 response remain unclear. Here a new iodoTMTRAQ proteomics technology was employed to analyze changes in protein redox modifications in Arabidopsis thaliana suspension cells in response to bicarbonate (mimic of elevated CO 2 ) in a time-course study. A total of 47 potential redox-regulated proteins were identified with functions in carbohydrate and energy metabolism, transport, ROS scavenging, cell structure modulation and protein turnover. This inventory of previously unknown redox responsive proteins in Arabidopsis bicarbonate responses lays a foundation for future research toward understanding the molecular mechanisms underlying plant CO 2 responses.
Bicarbonate Induced Redox Proteome Changes in Arabidopsis Suspension Cells

PubMed Central

Yin, Zepeng; Balmant, Kelly; Geng, Sisi; Zhu, Ning; Zhang, Tong; Dufresne, Craig; Dai, Shaojun; Chen, Sixue

2017-01-01

Climate change as a result of increasing atmospheric CO2 affects plant growth and productivity. CO2 is not only a carbon donor for photosynthesis but also an environmental signal that can perturb cellular redox homeostasis and lead to modifications of redox-sensitive proteins. Although redox regulation of protein functions has emerged as an important mechanism in several biological processes, protein redox modifications and how they function in plant CO2 response remain unclear. Here a new iodoTMTRAQ proteomics technology was employed to analyze changes in protein redox modifications in Arabidopsis thaliana suspension cells in response to bicarbonate (mimic of elevated CO2) in a time-course study. A total of 47 potential redox-regulated proteins were identified with functions in carbohydrate and energy metabolism, transport, ROS scavenging, cell structure modulation and protein turnover. This inventory of previously unknown redox responsive proteins in Arabidopsis bicarbonate responses lays a foundation for future research toward understanding the molecular mechanisms underlying plant CO2 responses. PMID:28184230

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