The Experts below are selected from a list of 270726 Experts worldwide ranked by ideXlab platform
Michael L Romero - One of the best experts on this subject based on the ideXlab platform.
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the effects of chronic psychological and Physical Stress on feather replacement in european starlings sturnus vulgaris
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2008Co-Authors: David E Strochlic, Michael L RomeroAbstract:Corticosterone (CORT) is seasonally modulated in many passerines, with plasma CORT concentrations lowest during the prebasic molt, when all feathers are replaced. Recent evidence indicating that CORT implants slow the rate of feather regrowth in molting birds suggests that plasma CORT concentrations are downregulated during molt in order to avoid the inhibition of feather growth caused by the protein catabolic activity of CORT. To further test this hypothesis, we examined whether endogenous CORT release, stimulated by exposure to either psychological Stress or Physical Stress (food restriction), could inhibit feather regrowth rates or decrease feather quality in birds undergoing an induced molt (feather replacement after plucking). European starlings (Sturnus vulgaris) were exposed to chronic psychological Stress or food restriction for three weeks of the feather regrowth period. Throughout this time, the length of growing primary, secondary, and tail feathers was measured and blood samples were collected to measure baseline and Stress-induced CORT concentrations. Upon completion of growth, feather quality was analyzed via measurements of mass, rachis length, feather area, and presence of fault bars. Both psychological and Physical Stress protocols elevated circulating plasma CORT but significantly less than implants from an earlier study did. Psychological Stress had no effect on feather regrowth rates or feather quality. Food restriction had no effect on feather growth rate but caused asynchronous feather replacement. When combined with psychological Stress, Physical Stress also resulted in smaller feather area. Results indicate that CORT implants may not accurately represent chronic Stress physiology. Additionally, the purpose for downregulating CORT concentrations during molt appears to be more complicated than simply protecting feather production from CORT's catabolic effects.
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the effects of chronic psychological and Physical Stress on feather replacement in european starlings sturnus vulgaris
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2008Co-Authors: David E Strochlic, Michael L RomeroAbstract:Corticosterone (CORT) is seasonally modulated in many passerines, with plasma CORT concentrations lowest during the prebasic molt, when all feathers are replaced. Recent evidence indicating that CORT implants slow the rate of feather regrowth in molting birds suggests that plasma CORT concentrations are downregulated during molt in order to avoid the inhibition of feather growth caused by the protein catabolic activity of CORT. To further test this hypothesis, we examined whether endogenous CORT release, stimulated by exposure to either psychological Stress or Physical Stress (food restriction), could inhibit feather regrowth rates or decrease feather quality in birds undergoing an induced molt (feather replacement after plucking). European starlings (Sturnus vulgaris) were exposed to chronic psychological Stress or food restriction for three weeks of the feather regrowth period. Throughout this time, the length of growing primary, secondary, and tail feathers was measured and blood samples were collected to measure baseline and Stress-induced CORT concentrations. Upon completion of growth, feather quality was analyzed via measurements of mass, rachis length, feather area, and presence of fault bars. Both psychological and Physical Stress protocols elevated circulating plasma CORT but significantly less than implants from an earlier study did. Psychological Stress had no effect on feather regrowth rates or feather quality. Food restriction had no effect on feather growth rate but caused asynchronous feather replacement. When combined with psychological Stress, Physical Stress also resulted in smaller feather area. Results indicate that CORT implants may not accurately represent chronic Stress physiology. Additionally, the purpose for downregulating CORT concentrations during molt appears to be more complicated than simply protecting feather production from CORT's catabolic effects.
Mark Hallett - One of the best experts on this subject based on the ideXlab platform.
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alteration of brain functional network at rest and in response to ymca Physical Stress test in concussed athletes rsfmri study
NeuroImage, 2011Co-Authors: Semyon Slobounov, Kai Zhang, Brian Johnson, D Pennell, Wayne J Sebastianelli, Silvina G Horovitz, Mark HallettAbstract:Abstract There is still controversy in the literature whether a single episode of mild traumatic brain injury (mTBI) results in short- and/or long-term functional and structural deficits in the concussed brain. With the inability of traditional brain imaging techniques to properly assess the severity of brain damage induced by a concussive blow, there is hope that more advanced applications such as resting state functional magnetic resonance imaging (rsFMRI) will be more specific in accurately diagnosing mTBI. In this rsFMRI study, we examined 17 subjects 10 ± 2 days post-sports-related mTBI and 17 age-matched normal volunteers (NVs) to investigate the possibility that the integrity of the resting state brain network is disrupted following a single concussive blow. We hypothesized that advanced brain imaging techniques may reveal subtle alterations of functional brain connections in asymptomatic mTBI subjects. There are several findings of interest. All mTBI subjects were asymptomatic based upon clinical evaluation and neuropsychological (NP) assessments prior to the MRI session. The mTBI subjects revealed a disrupted functional network both at rest and in response to the YMCA Physical Stress test. Specifically, interhemispheric connectivity was significantly reduced in the primary visual cortex, hippocampal and dorsolateral prefrontal cortex networks (p
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alteration of brain functional network at rest and in response to ymca Physical Stress test in concussed athletes rsfmri study
NeuroImage, 2011Co-Authors: Semyon Slobounov, Kai Zhang, D Pennell, Wayne J Sebastianelli, Silvina G Horovitz, Brian F G Johnson, Mark HallettAbstract:There is still controversy in the literature whether a single episode of mild traumatic brain injury (mTBI) results in short- and/or long-term functional and structural deficits in the concussed brain. With the inability of traditional brain imaging techniques to properly assess the severity of brain damage induced by a concussive blow, there is hope that more advanced applications such as resting state functional magnetic resonance imaging (rsFMRI) will be more specific in accurately diagnosing mTBI. In this rsFMRI study, we examined 17 subjects 10±2 days post-sports-related mTBI and 17 age-matched normal volunteers (NVs) to investigate the possibility that the integrity of the resting state brain network is disrupted following a single concussive blow. We hypothesized that advanced brain imaging techniques may reveal subtle alterations of functional brain connections in asymptomatic mTBI subjects. There are several findings of interest. All mTBI subjects were asymptomatic based upon clinical evaluation and neuropsychological (NP) assessments prior to the MRI session. The mTBI subjects revealed a disrupted functional network both at rest and in response to the YMCA Physical Stress test. Specifically, interhemispheric connectivity was significantly reduced in the primary visual cortex, hippocampal and dorsolateral prefrontal cortex networks (p<0.05). The YMCA Physical Stress induced nonspecific and similar changes in brain network connectivity patterns in both the mTBI and NV groups. These major findings are discussed in relation to underlying mechanisms, clinical assessment of mTBI, and current debate regarding functional brain connectivity in a clinical population. Overall, our major findings clearly indicate that functional brain alterations in the acute phase of injury are overlooked when conventional clinical and neuropsychological examinations are used.
David E Strochlic - One of the best experts on this subject based on the ideXlab platform.
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the effects of chronic psychological and Physical Stress on feather replacement in european starlings sturnus vulgaris
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2008Co-Authors: David E Strochlic, Michael L RomeroAbstract:Corticosterone (CORT) is seasonally modulated in many passerines, with plasma CORT concentrations lowest during the prebasic molt, when all feathers are replaced. Recent evidence indicating that CORT implants slow the rate of feather regrowth in molting birds suggests that plasma CORT concentrations are downregulated during molt in order to avoid the inhibition of feather growth caused by the protein catabolic activity of CORT. To further test this hypothesis, we examined whether endogenous CORT release, stimulated by exposure to either psychological Stress or Physical Stress (food restriction), could inhibit feather regrowth rates or decrease feather quality in birds undergoing an induced molt (feather replacement after plucking). European starlings (Sturnus vulgaris) were exposed to chronic psychological Stress or food restriction for three weeks of the feather regrowth period. Throughout this time, the length of growing primary, secondary, and tail feathers was measured and blood samples were collected to measure baseline and Stress-induced CORT concentrations. Upon completion of growth, feather quality was analyzed via measurements of mass, rachis length, feather area, and presence of fault bars. Both psychological and Physical Stress protocols elevated circulating plasma CORT but significantly less than implants from an earlier study did. Psychological Stress had no effect on feather regrowth rates or feather quality. Food restriction had no effect on feather growth rate but caused asynchronous feather replacement. When combined with psychological Stress, Physical Stress also resulted in smaller feather area. Results indicate that CORT implants may not accurately represent chronic Stress physiology. Additionally, the purpose for downregulating CORT concentrations during molt appears to be more complicated than simply protecting feather production from CORT's catabolic effects.
-
the effects of chronic psychological and Physical Stress on feather replacement in european starlings sturnus vulgaris
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2008Co-Authors: David E Strochlic, Michael L RomeroAbstract:Corticosterone (CORT) is seasonally modulated in many passerines, with plasma CORT concentrations lowest during the prebasic molt, when all feathers are replaced. Recent evidence indicating that CORT implants slow the rate of feather regrowth in molting birds suggests that plasma CORT concentrations are downregulated during molt in order to avoid the inhibition of feather growth caused by the protein catabolic activity of CORT. To further test this hypothesis, we examined whether endogenous CORT release, stimulated by exposure to either psychological Stress or Physical Stress (food restriction), could inhibit feather regrowth rates or decrease feather quality in birds undergoing an induced molt (feather replacement after plucking). European starlings (Sturnus vulgaris) were exposed to chronic psychological Stress or food restriction for three weeks of the feather regrowth period. Throughout this time, the length of growing primary, secondary, and tail feathers was measured and blood samples were collected to measure baseline and Stress-induced CORT concentrations. Upon completion of growth, feather quality was analyzed via measurements of mass, rachis length, feather area, and presence of fault bars. Both psychological and Physical Stress protocols elevated circulating plasma CORT but significantly less than implants from an earlier study did. Psychological Stress had no effect on feather regrowth rates or feather quality. Food restriction had no effect on feather growth rate but caused asynchronous feather replacement. When combined with psychological Stress, Physical Stress also resulted in smaller feather area. Results indicate that CORT implants may not accurately represent chronic Stress physiology. Additionally, the purpose for downregulating CORT concentrations during molt appears to be more complicated than simply protecting feather production from CORT's catabolic effects.
Semyon Slobounov - One of the best experts on this subject based on the ideXlab platform.
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alteration of brain functional network at rest and in response to ymca Physical Stress test in concussed athletes rsfmri study
NeuroImage, 2011Co-Authors: Semyon Slobounov, Kai Zhang, Brian Johnson, D Pennell, Wayne J Sebastianelli, Silvina G Horovitz, Mark HallettAbstract:Abstract There is still controversy in the literature whether a single episode of mild traumatic brain injury (mTBI) results in short- and/or long-term functional and structural deficits in the concussed brain. With the inability of traditional brain imaging techniques to properly assess the severity of brain damage induced by a concussive blow, there is hope that more advanced applications such as resting state functional magnetic resonance imaging (rsFMRI) will be more specific in accurately diagnosing mTBI. In this rsFMRI study, we examined 17 subjects 10 ± 2 days post-sports-related mTBI and 17 age-matched normal volunteers (NVs) to investigate the possibility that the integrity of the resting state brain network is disrupted following a single concussive blow. We hypothesized that advanced brain imaging techniques may reveal subtle alterations of functional brain connections in asymptomatic mTBI subjects. There are several findings of interest. All mTBI subjects were asymptomatic based upon clinical evaluation and neuropsychological (NP) assessments prior to the MRI session. The mTBI subjects revealed a disrupted functional network both at rest and in response to the YMCA Physical Stress test. Specifically, interhemispheric connectivity was significantly reduced in the primary visual cortex, hippocampal and dorsolateral prefrontal cortex networks (p
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alteration of brain functional network at rest and in response to ymca Physical Stress test in concussed athletes rsfmri study
NeuroImage, 2011Co-Authors: Semyon Slobounov, Kai Zhang, D Pennell, Wayne J Sebastianelli, Silvina G Horovitz, Brian F G Johnson, Mark HallettAbstract:There is still controversy in the literature whether a single episode of mild traumatic brain injury (mTBI) results in short- and/or long-term functional and structural deficits in the concussed brain. With the inability of traditional brain imaging techniques to properly assess the severity of brain damage induced by a concussive blow, there is hope that more advanced applications such as resting state functional magnetic resonance imaging (rsFMRI) will be more specific in accurately diagnosing mTBI. In this rsFMRI study, we examined 17 subjects 10±2 days post-sports-related mTBI and 17 age-matched normal volunteers (NVs) to investigate the possibility that the integrity of the resting state brain network is disrupted following a single concussive blow. We hypothesized that advanced brain imaging techniques may reveal subtle alterations of functional brain connections in asymptomatic mTBI subjects. There are several findings of interest. All mTBI subjects were asymptomatic based upon clinical evaluation and neuropsychological (NP) assessments prior to the MRI session. The mTBI subjects revealed a disrupted functional network both at rest and in response to the YMCA Physical Stress test. Specifically, interhemispheric connectivity was significantly reduced in the primary visual cortex, hippocampal and dorsolateral prefrontal cortex networks (p<0.05). The YMCA Physical Stress induced nonspecific and similar changes in brain network connectivity patterns in both the mTBI and NV groups. These major findings are discussed in relation to underlying mechanisms, clinical assessment of mTBI, and current debate regarding functional brain connectivity in a clinical population. Overall, our major findings clearly indicate that functional brain alterations in the acute phase of injury are overlooked when conventional clinical and neuropsychological examinations are used.
Wayne J Sebastianelli - One of the best experts on this subject based on the ideXlab platform.
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alteration of brain functional network at rest and in response to ymca Physical Stress test in concussed athletes rsfmri study
NeuroImage, 2011Co-Authors: Semyon Slobounov, Kai Zhang, Brian Johnson, D Pennell, Wayne J Sebastianelli, Silvina G Horovitz, Mark HallettAbstract:Abstract There is still controversy in the literature whether a single episode of mild traumatic brain injury (mTBI) results in short- and/or long-term functional and structural deficits in the concussed brain. With the inability of traditional brain imaging techniques to properly assess the severity of brain damage induced by a concussive blow, there is hope that more advanced applications such as resting state functional magnetic resonance imaging (rsFMRI) will be more specific in accurately diagnosing mTBI. In this rsFMRI study, we examined 17 subjects 10 ± 2 days post-sports-related mTBI and 17 age-matched normal volunteers (NVs) to investigate the possibility that the integrity of the resting state brain network is disrupted following a single concussive blow. We hypothesized that advanced brain imaging techniques may reveal subtle alterations of functional brain connections in asymptomatic mTBI subjects. There are several findings of interest. All mTBI subjects were asymptomatic based upon clinical evaluation and neuropsychological (NP) assessments prior to the MRI session. The mTBI subjects revealed a disrupted functional network both at rest and in response to the YMCA Physical Stress test. Specifically, interhemispheric connectivity was significantly reduced in the primary visual cortex, hippocampal and dorsolateral prefrontal cortex networks (p
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alteration of brain functional network at rest and in response to ymca Physical Stress test in concussed athletes rsfmri study
NeuroImage, 2011Co-Authors: Semyon Slobounov, Kai Zhang, D Pennell, Wayne J Sebastianelli, Silvina G Horovitz, Brian F G Johnson, Mark HallettAbstract:There is still controversy in the literature whether a single episode of mild traumatic brain injury (mTBI) results in short- and/or long-term functional and structural deficits in the concussed brain. With the inability of traditional brain imaging techniques to properly assess the severity of brain damage induced by a concussive blow, there is hope that more advanced applications such as resting state functional magnetic resonance imaging (rsFMRI) will be more specific in accurately diagnosing mTBI. In this rsFMRI study, we examined 17 subjects 10±2 days post-sports-related mTBI and 17 age-matched normal volunteers (NVs) to investigate the possibility that the integrity of the resting state brain network is disrupted following a single concussive blow. We hypothesized that advanced brain imaging techniques may reveal subtle alterations of functional brain connections in asymptomatic mTBI subjects. There are several findings of interest. All mTBI subjects were asymptomatic based upon clinical evaluation and neuropsychological (NP) assessments prior to the MRI session. The mTBI subjects revealed a disrupted functional network both at rest and in response to the YMCA Physical Stress test. Specifically, interhemispheric connectivity was significantly reduced in the primary visual cortex, hippocampal and dorsolateral prefrontal cortex networks (p<0.05). The YMCA Physical Stress induced nonspecific and similar changes in brain network connectivity patterns in both the mTBI and NV groups. These major findings are discussed in relation to underlying mechanisms, clinical assessment of mTBI, and current debate regarding functional brain connectivity in a clinical population. Overall, our major findings clearly indicate that functional brain alterations in the acute phase of injury are overlooked when conventional clinical and neuropsychological examinations are used.
