Search results for "Response"

Neural Mechanisms Underlying Human Auditory Evoked Responses Revealed By Human Neocortical Neurosolver

2022

Funding Information: This study was supported by National Institutes of Health (Grant Nos. NIBIB RO1 EB022889, NIMH RO1 MH106174). Publisher Copyright: © 2021, The Author(s). Auditory evoked fields (AEFs) are commonly studied, yet their underlying neural mechanisms remain poorly understood. Here, we used the biophysical modelling software Human Neocortical Neurosolver (HNN) whose foundation is a canonical neocortical circuit model to interpret the cell and network mechanisms contributing to macroscale AEFs elicited by a simple tone, measured with magnetoencephalography. We found that AEFs can be reproduced by activating the neocortical circuit through a layer specific sequence of feedforwar…

A correction method for dynamic analysis of linear continuous systems

2005

A method to improve the dynamic response analysis of continuous classically damped linear system is proposed. As in fact usually, following a classical approach, a reduced number of eigenfunctions are accounted for and the response is evaluated by integrating the uncoupled differential equations of motion in modal space, neglecting the contribution of high frequency modes (truncation procedure). Here, starting from the given system, it is proposed to set up two differential equations governing the motion of two new continuous systems: the first one contains only the first m non-zero eigenvalues of the given system and the second one contains the remainder non-zero infinity - m eigenvalues. …

Prophenoloxidase activating system in tunicate hemolymph

1996

The activation sequence and related factors of the prophenoloxidase activating system in crustaceans was compared with the equivalent system in tunicates. Both solitary and colonial ascidians present in their hemolymph a copper-dependent phenoloxidase activity that may be inhibited by tropolone and phenylthiourea. Carbohydrates are able, to various extents, to trigger proPO system which requires serine protease cleavage for activation to phenoloxidase (PO). In some ascidians, hemocytes called ≪morula cells≫ show PO activity, while in Ciona intestinalis the ≪univacuolar refractile granulocytes≫ are positive after cytochemical staining with L-dopa. The relationships between proPO system and d…

Epidemiological analysis of Salmonella enterica from beef sampled in the slaughterhouse and retailers in Dakar (Senegal) using pulsed-field gel elect…

2007

Seventy-eight isolates of Salmonella spp. isolated from beef sampled from the official city slaughterhouse and from retailers in Dakar, Senegal were analyzed using serotyping, antimicrobial testing and macrorestriction profiling by Pulsed-Field Gel Electrophoresis (PFGE). These analyses were done to identify clonal relationships and potential transmission routes in beef channel. XbaI macrorestriction allowed defining 17 genotypes among the six main analyzed serotypes: Salmonella bredeney (3 genotypes), S. muenster (6), S. waycross (1), S. corvallis (3), S. kentucky (1) and S. brandenburg (3). The cross analysis of PFGE profiles and origin of the beef samples reveals a wide range of contamin…

Serum Response Factor-Mediated Gene Regulation in a Drosophila Visual Working Memory

2013

Summary Background Navigation through the environment requires a working memory for the chosen target and path integration facilitating an approach when the target becomes temporarily hidden. We have previously shown that this visual orientation memory resides in the ellipsoid body, which is part of the central complex in the Drosophila brain. Former analysis of  foraging and ignorant mutants have revealed that a hierarchical PKG and RSKII kinase signaling cascade in a subset of the ellipsoid-body ring neurons is required for this type of working memory in flies. Results Here we show that mutants in the ellipsoid body open  ( ebo ) gene, which encodes the actin-binding protein Exportin 6, e…

Different hormonal response to continuous and intermittent exercise in middle-distance and marathon runners

2008

In order to study the effects of different athletic backgrounds on exercise-induced hormonal responses, serum testosterone, luteinizing hormone, follicle-stimulating hormone and cortisol concentrations were measured before and after intensive continuous and intermittent running in well-trained middle-distance runners (MID) and marathon runners (MAR). They performed two 40-min exercises on a treadmill: a continuous run at an intensity of 80% [tempo run (TR)] and an intermittent run (IR) at an intensity of 100% of the velocity associated with VO(2max). The testosterone response to IR and the cortisol response to TR was higher (P<0.05) in MID compared with MAR. The testosterone response to IR …

The role of chemical cues in the host finding behaviour of Trissolcus basalis from a Conservation Biological Control perspective

In assessing successful biological control programs by parasitoids, the knowledge of important traits, such as the host finding capability, i.e. the ability to find host and food resources, play the key role. Moreover, parasitoids in their natural environment parasitoids deal with a variable mixtures of natural cues. Some chemical cues are used by the wasps to locate their hosts, some ones drive wasps to feeding resources. The parasitoid response to these cues can fluctuate according to biotic factors and abiotic condition. This dissertation focus in details on the role of two important tools, such as selective flowering plants as food resources to add within a crop area and the traces left…

Bacillus thuringiensis treatment alters larval growth, hemocytes and modulation of Hsp70 in Rhynchophorus ferrugineus

2011

To study the pathogen-host relationship, we used the model of the entomopathogenic bacterium Bacillus thuringiensis (Bt) and Rhynchophorus ferrugineus, a quarantine pest that attacks the palm trees. In particular, we focused on the Bt stress-induced infections. We studied the effect of Bt on larval growth, on hemocytes and on the expression of the heat shock proteins (Hsp70). HSPs are rapidly synthesized in the cells after a stress exposition including pathogens. The Hsp70 was evaluated in the supernatant of the hemocyte lysate (HLS) obtained from larvae fed with Bt. This is the first time that the presence of Hsp70 has been recorded in R. ferrugineus. Bt has negative effects on larval grow…

Effects of Grazing on the Behaviour, Oxidative and Immune Status, and Production of Organic Dairy Cows

2019

This study compared the effects of a short daily grazing time with those of permanent free-stall housing on the behaviour, oxidative status, immune response, and milk production of organically reared cows. During a 63-day period, two homogeneous groups of eight lactating Brown cows were allocated to either housing (H) in a free-stall building for 24 h/day. Feeding was based on a total mixed ration or grazing (G) on barley grass for 5 h/day, and housing in a free-stall structure with feeding was based on the same total mixed ration offered to the H group. With regard to behaviour, H cows spent more time idling, walking, drinking, and self-grooming, whereas G cows showed a greater intent to e…

Thermal adaptation and physiological responses to environmental stress in tunicates

2017

Understanding the multifaceted nature of environmental fluctuations is crucial to predicting the physiological adjustments utilised by organisms in resisting or adapting to changes over time. Here we investigate the effects of 2 environmental stressors on tunicates, whose fitness can have important repercussions on the quality of habitat. Specifically, we report respiration rate (RR), clearance rate (CR), and assimilation efficiency (AE) of the ascidian Styela plicata in response to a range of temperatures and varying food availability. Temperature-dependent RR was observed only within a portion of the thermal window of the species. Significant differences in clearance rates were detected a…