Weeds in a changing climate : Vulnerabilities, consequences, and implications for future weed management
- Ramesh, Kulasekaran, Matloob, Amar, Aslam, Farhena, Florentine, Singarayer, Chauhan, Bhagirath
- Authors: Ramesh, Kulasekaran , Matloob, Amar , Aslam, Farhena , Florentine, Singarayer , Chauhan, Bhagirath
- Date: 2017
- Type: Text , Journal article
- Relation: Frontiers in Plant Science Vol. 8, no. (2017), p. 1-13
- Full Text:
- Reviewed:
- Description: Whilst it is agreed that climate change will impact on the long-term interactions between crops and weeds, the results of this impact are far from clear. We suggest that a thorough understanding of weed dominance and weed interactions, depending on crop and weed ecosystems and crop sequences in the ecosystem, will be the key determining factor for successful weed management. Indeed, we claim that recent changes observed throughout the world within the weed spectrum in different cropping systems which were ostensibly related to climate change, warrant a deeper examination of weed vulnerabilities before a full understanding is reached. For example, the uncontrolled establishment of weeds in crops leads to a mixed population, in terms of C3 and C4 pathways, and this poses a considerable level of complexity for weed management. There is a need to include all possible combinations of crops and weeds while studying the impact of climate change on crop-weed competitive interactions, since, from a weed management perspective, C4 weeds would flourish in the increased temperature scenario and pose serious yield penalties. This is particularly alarming as a majority of the most competitive weeds are C4 plants. Although CO2 is considered as a main contributing factor for climate change, a few Australian studies have also predicted differing responses of weed species due to shifts in rainfall patterns. Reduced water availability, due to recurrent and unforeseen droughts, would alter the competitive balance between crops and some weed species, intensifying the crop-weed competition pressure. Although it is recognized that the weed pressure associated with climate change is a significant threat to crop production, either through increased temperatures, rainfall shift, and elevated CO2 levels, the current knowledge of this effect is very sparse. A few models that have attempted to predict these interactions are discussed in this paper, since these models could play an integral role in developing future management programs for future weed threats. This review has presented a comprehensive discussion of the recent research in this area, and has identified key deficiencies which need further research in crop-weed eco-systems to formulate suitable control measures before the real impacts of climate change set in. © 2017 Ramesh, Matloob, Aslam, Florentine and Chauhan.
- Authors: Ramesh, Kulasekaran , Matloob, Amar , Aslam, Farhena , Florentine, Singarayer , Chauhan, Bhagirath
- Date: 2017
- Type: Text , Journal article
- Relation: Frontiers in Plant Science Vol. 8, no. (2017), p. 1-13
- Full Text:
- Reviewed:
- Description: Whilst it is agreed that climate change will impact on the long-term interactions between crops and weeds, the results of this impact are far from clear. We suggest that a thorough understanding of weed dominance and weed interactions, depending on crop and weed ecosystems and crop sequences in the ecosystem, will be the key determining factor for successful weed management. Indeed, we claim that recent changes observed throughout the world within the weed spectrum in different cropping systems which were ostensibly related to climate change, warrant a deeper examination of weed vulnerabilities before a full understanding is reached. For example, the uncontrolled establishment of weeds in crops leads to a mixed population, in terms of C3 and C4 pathways, and this poses a considerable level of complexity for weed management. There is a need to include all possible combinations of crops and weeds while studying the impact of climate change on crop-weed competitive interactions, since, from a weed management perspective, C4 weeds would flourish in the increased temperature scenario and pose serious yield penalties. This is particularly alarming as a majority of the most competitive weeds are C4 plants. Although CO2 is considered as a main contributing factor for climate change, a few Australian studies have also predicted differing responses of weed species due to shifts in rainfall patterns. Reduced water availability, due to recurrent and unforeseen droughts, would alter the competitive balance between crops and some weed species, intensifying the crop-weed competition pressure. Although it is recognized that the weed pressure associated with climate change is a significant threat to crop production, either through increased temperatures, rainfall shift, and elevated CO2 levels, the current knowledge of this effect is very sparse. A few models that have attempted to predict these interactions are discussed in this paper, since these models could play an integral role in developing future management programs for future weed threats. This review has presented a comprehensive discussion of the recent research in this area, and has identified key deficiencies which need further research in crop-weed eco-systems to formulate suitable control measures before the real impacts of climate change set in. © 2017 Ramesh, Matloob, Aslam, Florentine and Chauhan.
Muscle-enriched MicroRNAs isolated from whole blood are regulated by exercise and are potential biomarkers of cardiorespiratory fitness
- Denham, Joshua, Prestes, Priscilla
- Authors: Denham, Joshua , Prestes, Priscilla
- Date: 2016
- Type: Text , Journal article
- Relation: Frontiers in Genetics Vol. 7, no. NOV (2016), p. 1-8
- Full Text:
- Reviewed:
- Description: MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression post-transcriptionally. Evidence indicating miRNAs influence exercise-induced health and performance adaptations is mounting. Circulating miRNAs are responsible for intercellular communication and could serve as biomarkers for disease and exercise-related traits. Such biomarkers would contribute to exercise screening, monitoring, and the development of personalized exercise prescription. Accordingly, we investigated the impact of long-term strenuous aerobic exercise training and a single bout of maximal aerobic exercise on five muscle-enriched miRNAs implicated in exercise adaptations (miR-1, miR-133a, miR-181a, miR-486, and miR-494). We also determined linear correlations between miRNAs, resting heart rate, and maximum oxygen uptake (V˙O2 max). We used TaqMan assay quantitative polymerase chain reaction to analyze the abundance of miR-1, miR-133a, miR-181a, miR-486, and miR-494 in resting whole blood of 67 endurance athletes and 61 healthy controls. Relative to controls, endurance athletes exhibited increased miR-1, miR-486, and miR-494 content (1.26- to 1.58-fold change, all p < 0.05). miR-1, miR-133a, and miR-486 were decreased immediately after maximal aerobic exercise (0.64- to 0.76-fold change, all p < 0.01) performed by 19 healthy, young men (20.7 ± 2.4 years). Finally, we observed positive correlations between miRNA abundance and V˙ O2 max (miR-1 and miR-486) and an inverse correlation between miR-486 and resting heart rate. Therefore, muscle-enriched miRNAs isolated from whole blood are regulated by acute and long-term aerobic exercise training and could serve as biomarkers of cardiorespiratory fitness. © 2016 Denham and Prestes.
- Authors: Denham, Joshua , Prestes, Priscilla
- Date: 2016
- Type: Text , Journal article
- Relation: Frontiers in Genetics Vol. 7, no. NOV (2016), p. 1-8
- Full Text:
- Reviewed:
- Description: MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression post-transcriptionally. Evidence indicating miRNAs influence exercise-induced health and performance adaptations is mounting. Circulating miRNAs are responsible for intercellular communication and could serve as biomarkers for disease and exercise-related traits. Such biomarkers would contribute to exercise screening, monitoring, and the development of personalized exercise prescription. Accordingly, we investigated the impact of long-term strenuous aerobic exercise training and a single bout of maximal aerobic exercise on five muscle-enriched miRNAs implicated in exercise adaptations (miR-1, miR-133a, miR-181a, miR-486, and miR-494). We also determined linear correlations between miRNAs, resting heart rate, and maximum oxygen uptake (V˙O2 max). We used TaqMan assay quantitative polymerase chain reaction to analyze the abundance of miR-1, miR-133a, miR-181a, miR-486, and miR-494 in resting whole blood of 67 endurance athletes and 61 healthy controls. Relative to controls, endurance athletes exhibited increased miR-1, miR-486, and miR-494 content (1.26- to 1.58-fold change, all p < 0.05). miR-1, miR-133a, and miR-486 were decreased immediately after maximal aerobic exercise (0.64- to 0.76-fold change, all p < 0.01) performed by 19 healthy, young men (20.7 ± 2.4 years). Finally, we observed positive correlations between miRNA abundance and V˙ O2 max (miR-1 and miR-486) and an inverse correlation between miR-486 and resting heart rate. Therefore, muscle-enriched miRNAs isolated from whole blood are regulated by acute and long-term aerobic exercise training and could serve as biomarkers of cardiorespiratory fitness. © 2016 Denham and Prestes.
Yes : The symptoms of OCD and depression are discrete and not exclusively negative affectivity
- Moore, Kathleen, Howell, Jacqui
- Authors: Moore, Kathleen , Howell, Jacqui
- Date: 2017
- Type: Text , Journal article
- Relation: Frontiers in Psychology Vol. 8, no. MAY (2017), p. 1-10
- Full Text:
- Reviewed:
- Description: Although Obsessive-Compulsive Disorder (OCD) and Depression are classified as separate disorders, the high incidence of co-morbidity and the strong correlations between measures of each has led to debate about the nature of their relationship. Some authors have proposed that OCD is in fact a mood disorder while others have suggested that the two disorders are grounded in negative affectivity. A third proposition is that depression is an essential part of OCD but that OCD is a separate disorder from depression. The aim in this study was to investigate these diverse propositions in a non-clinical sample and also to determine whether factors implicated in each, that is anxious and depressive cognitions, hopelessness, and self-criticism, would demonstrate commonality as predictors of the symptoms of OCD and of depression. Two hundred participants (59% female) (M age = 34 years, SD = 16) completed the Padua Inventory, Carroll Rating Scale, Cognitions Checklist, Self-Criticism Scale, Beck Hopelessness Scale, Buss-Durkee Hostility Inventory-Revised and a Negative Affectivity Schedule. Results indicated a strong correlation between OCD and depression, depression, and negative affectivity but a weaker relationship between OCD and negative affectivity. Path analyses revealed that both anxious and depressive cognitions, as well as hostility predicted both disorders but the Beta-weights were stronger on OCD. Self-criticism predicted only depression while hopelessness failed to predict either disorder but was itself predicted by depressive cognitions. Depression was a stronger indicator of negative affect than OCD and while OCD positively predicted depression, depression was a negative indicator of OCD. These results support the hypothesis that OCD and depression are discrete disorders and indicate that while depression is implicated in OCD, the reverse does not hold. While both disorders are related to negative affectivity, this relationship is much stronger for depression thus failing to confirm that both are subsumed by a common factor, in this case, negative affectivity. The proposition that depression is part of OCD but that OCD is not necessarily implicated in depression and is, in fact, a separate disorder, is supported by the current model. Further research is required to support the utility of the model in clinical samples. © 2017 Moore and Howell.
- Authors: Moore, Kathleen , Howell, Jacqui
- Date: 2017
- Type: Text , Journal article
- Relation: Frontiers in Psychology Vol. 8, no. MAY (2017), p. 1-10
- Full Text:
- Reviewed:
- Description: Although Obsessive-Compulsive Disorder (OCD) and Depression are classified as separate disorders, the high incidence of co-morbidity and the strong correlations between measures of each has led to debate about the nature of their relationship. Some authors have proposed that OCD is in fact a mood disorder while others have suggested that the two disorders are grounded in negative affectivity. A third proposition is that depression is an essential part of OCD but that OCD is a separate disorder from depression. The aim in this study was to investigate these diverse propositions in a non-clinical sample and also to determine whether factors implicated in each, that is anxious and depressive cognitions, hopelessness, and self-criticism, would demonstrate commonality as predictors of the symptoms of OCD and of depression. Two hundred participants (59% female) (M age = 34 years, SD = 16) completed the Padua Inventory, Carroll Rating Scale, Cognitions Checklist, Self-Criticism Scale, Beck Hopelessness Scale, Buss-Durkee Hostility Inventory-Revised and a Negative Affectivity Schedule. Results indicated a strong correlation between OCD and depression, depression, and negative affectivity but a weaker relationship between OCD and negative affectivity. Path analyses revealed that both anxious and depressive cognitions, as well as hostility predicted both disorders but the Beta-weights were stronger on OCD. Self-criticism predicted only depression while hopelessness failed to predict either disorder but was itself predicted by depressive cognitions. Depression was a stronger indicator of negative affect than OCD and while OCD positively predicted depression, depression was a negative indicator of OCD. These results support the hypothesis that OCD and depression are discrete disorders and indicate that while depression is implicated in OCD, the reverse does not hold. While both disorders are related to negative affectivity, this relationship is much stronger for depression thus failing to confirm that both are subsumed by a common factor, in this case, negative affectivity. The proposition that depression is part of OCD but that OCD is not necessarily implicated in depression and is, in fact, a separate disorder, is supported by the current model. Further research is required to support the utility of the model in clinical samples. © 2017 Moore and Howell.
Structure of the Wechsler intelligence scale for children - Fourth edition in a group of children with ADHD
- Gomez, Rapson, Vance, Alasdair, Watson, Shaun
- Authors: Gomez, Rapson , Vance, Alasdair , Watson, Shaun
- Date: 2016
- Type: Text , Journal article
- Relation: Frontiers in Psychology Vol. 7, no. MAY (2016), p. 1-11
- Full Text:
- Reviewed:
- Description: Objective: This study used confirmatory factor analysis to examine the factor structure for the 10 core WISC-IV subtests in a group of children (N = 812) with ADHD. Method: The study examined oblique four- and five-factor models, higher order models with one general secondary factor and four and five primary factors, and a bifactor model with a general factor and four specific factors. Results: The findings supported all models tested, with the bifactor model being the optimum model. For this model, only the general factor had high explained common variance and omega hierarchical value, and it predicted reading and arithmetic abilities. Conclusion: The findings favor the use of the FSIQ scores of the WISC-IV, but not the subscale index scores. © 2016 Gomez, Vance and Watson.
- Authors: Gomez, Rapson , Vance, Alasdair , Watson, Shaun
- Date: 2016
- Type: Text , Journal article
- Relation: Frontiers in Psychology Vol. 7, no. MAY (2016), p. 1-11
- Full Text:
- Reviewed:
- Description: Objective: This study used confirmatory factor analysis to examine the factor structure for the 10 core WISC-IV subtests in a group of children (N = 812) with ADHD. Method: The study examined oblique four- and five-factor models, higher order models with one general secondary factor and four and five primary factors, and a bifactor model with a general factor and four specific factors. Results: The findings supported all models tested, with the bifactor model being the optimum model. For this model, only the general factor had high explained common variance and omega hierarchical value, and it predicted reading and arithmetic abilities. Conclusion: The findings favor the use of the FSIQ scores of the WISC-IV, but not the subscale index scores. © 2016 Gomez, Vance and Watson.
Confirmatory factor analysis of the combined social phobia scale and social interaction anxiety scale : Support for a bifactor model
- Gomez, Rapson, Watson, Shaun
- Authors: Gomez, Rapson , Watson, Shaun
- Date: 2017
- Type: Text , Journal article
- Relation: Frontiers in Psychology Vol. 8, no. (2017), p. 1-13
- Full Text:
- Reviewed:
- Description: For the Social Phobia Scale (SPS) and the Social Interaction Anxiety Scale (SIAS) together, this study examined support for a bifactor model, and also the internal consistency reliability and external validity of the factors in this model. Participants (N = 526) were adults from the general community who completed the SPS and SIAS. Confirmatory factor analysis (CFA) of their ratings indicated good support for the bifactor model. For this model, the loadings for all but six items were higher on the general factor than the specific factors. The three positively worded items had negligible loadings on the general factor. The general factor explained most of the common variance in the SPS and SIAS, and demonstrated good model-based internal consistency reliability (omega hierarchical) and a strong association with fear of negative evaluation and extraversion. The practical implications of the findings for the utilization of the SPS and SIAS, and the theoretical and clinical implications for social anxiety are discussed. © 2017 Gomez and Watson.
- Authors: Gomez, Rapson , Watson, Shaun
- Date: 2017
- Type: Text , Journal article
- Relation: Frontiers in Psychology Vol. 8, no. (2017), p. 1-13
- Full Text:
- Reviewed:
- Description: For the Social Phobia Scale (SPS) and the Social Interaction Anxiety Scale (SIAS) together, this study examined support for a bifactor model, and also the internal consistency reliability and external validity of the factors in this model. Participants (N = 526) were adults from the general community who completed the SPS and SIAS. Confirmatory factor analysis (CFA) of their ratings indicated good support for the bifactor model. For this model, the loadings for all but six items were higher on the general factor than the specific factors. The three positively worded items had negligible loadings on the general factor. The general factor explained most of the common variance in the SPS and SIAS, and demonstrated good model-based internal consistency reliability (omega hierarchical) and a strong association with fear of negative evaluation and extraversion. The practical implications of the findings for the utilization of the SPS and SIAS, and the theoretical and clinical implications for social anxiety are discussed. © 2017 Gomez and Watson.
Glyphosate Resistance of C-3 and C-4 Weeds under Rising Atmospheric CO2
- Fernando, Nimesha, Manalil, Sudheesh, Florentine, Singarayer, Chauhan, Bhagirath, Seneweera, Saman
- Authors: Fernando, Nimesha , Manalil, Sudheesh , Florentine, Singarayer , Chauhan, Bhagirath , Seneweera, Saman
- Date: 2016
- Type: Text , Journal article , Review
- Relation: Frontiers in Plant Science Vol. 7, no. (Jun 2016), p. 1-11
- Full Text:
- Reviewed:
- Description: The present paper reviews current knowledge on how changes of plant metabolism under elevated CO2 concentrations (e[CO2]) can affect the development of the glyphosate resistance of C-3 and C-4 weeds. Among the chemical herbicides, glyphosate, which is a non-selective and post-emergence herbicide, is currently the most widely used herbicide in global agriculture. As a consequence, glyphosate resistant weeds, particularly in major field crops, are a widespread problem and are becoming a significant challenge to future global food production. Of particular interest here it is known that the biochemical processes involved in photosynthetic pathways of C-3 and C-4 plants are different, which may have relevance to their competitive development under changing environmental conditions. It has already been shown that plant anatomical, morphological, and physiological changes under e[CO2] can be different, based on (i) the plant's functional group, (ii) the available soil nutrients, and (iii) the governing water status. In this respect, C-3 species are likely to have a major developmental advantage under a CO2 rich atmosphere, by being able to capitalize on the overall stimulatory effect of e[CO2]. For example, many tropical weed grass species fix CO2 from the atmosphere via the C-4 photosynthetic pathway, which is a complex anatomical and biochemical variant of the C-3 pathway. Thus, based on our current knowledge of CO2 fixing, it would appear obvious that the development of a glyphosate-resistant mechanism would be easier under an e[CO2] in C-3 weeds which have a simpler photosynthetic pathway, than for C-4 weeds. However, notwithstanding this logical argument, a better understanding of the biochemical, genetic, and molecular measures by which plants develop glyphosate resistance and how e[CO2] affects these measures will be important before attempting to innovate sustainable technology to manage the glyphosate-resistant evolution of weeds under e[CO2]. Such information will be of essential in managing weed control by herbicide use, and to thus ensure an increase in global food production in the event of increased atmospheric [CO2] levels.
- Authors: Fernando, Nimesha , Manalil, Sudheesh , Florentine, Singarayer , Chauhan, Bhagirath , Seneweera, Saman
- Date: 2016
- Type: Text , Journal article , Review
- Relation: Frontiers in Plant Science Vol. 7, no. (Jun 2016), p. 1-11
- Full Text:
- Reviewed:
- Description: The present paper reviews current knowledge on how changes of plant metabolism under elevated CO2 concentrations (e[CO2]) can affect the development of the glyphosate resistance of C-3 and C-4 weeds. Among the chemical herbicides, glyphosate, which is a non-selective and post-emergence herbicide, is currently the most widely used herbicide in global agriculture. As a consequence, glyphosate resistant weeds, particularly in major field crops, are a widespread problem and are becoming a significant challenge to future global food production. Of particular interest here it is known that the biochemical processes involved in photosynthetic pathways of C-3 and C-4 plants are different, which may have relevance to their competitive development under changing environmental conditions. It has already been shown that plant anatomical, morphological, and physiological changes under e[CO2] can be different, based on (i) the plant's functional group, (ii) the available soil nutrients, and (iii) the governing water status. In this respect, C-3 species are likely to have a major developmental advantage under a CO2 rich atmosphere, by being able to capitalize on the overall stimulatory effect of e[CO2]. For example, many tropical weed grass species fix CO2 from the atmosphere via the C-4 photosynthetic pathway, which is a complex anatomical and biochemical variant of the C-3 pathway. Thus, based on our current knowledge of CO2 fixing, it would appear obvious that the development of a glyphosate-resistant mechanism would be easier under an e[CO2] in C-3 weeds which have a simpler photosynthetic pathway, than for C-4 weeds. However, notwithstanding this logical argument, a better understanding of the biochemical, genetic, and molecular measures by which plants develop glyphosate resistance and how e[CO2] affects these measures will be important before attempting to innovate sustainable technology to manage the glyphosate-resistant evolution of weeds under e[CO2]. Such information will be of essential in managing weed control by herbicide use, and to thus ensure an increase in global food production in the event of increased atmospheric [CO2] levels.
Duration-dependent effects of the BDNF Val66Met polymorphism on anodal tDCS induced motor cortex plasticity in older adults : A group and individual perspective
- Puri, Rohan, Hinder, Mark, Fujiyama, Hakuei, Gomez, Rapson, Carson, Richard, Summers, Jeff
- Authors: Puri, Rohan , Hinder, Mark , Fujiyama, Hakuei , Gomez, Rapson , Carson, Richard , Summers, Jeff
- Date: 2015
- Type: Text , Journal article
- Relation: Frontiers in Aging Neuroscience Vol. 7, no. JUN (2015), p. 1-10
- Full Text:
- Reviewed:
- Description: The brain derived neurotrophic factor (BDNF) Val66Met polymorphism and stimulation duration are thought to play an important role in modulating motor cortex plasticity induced by non-invasive brain stimulation (NBS). In the present study we sought to determine whether these factors interact or exert independent effects in older adults. Fifty-four healthy older adults (mean age = 66.85 years) underwent two counterbalanced sessions of 1.5 mA anodal transcranial direct current stimulation (atDCS), applied over left M1 for either 10 or 20 min. Single pulse transcranial magnetic stimulation (TMS) was used to assess corticospinal excitability (CSE) before and every 5 min for 30 min following atDCS. On a group level, there was an interaction between stimulation duration and BDNF genotype, with Met carriers (n = 13) showing greater post-intervention potentiation of CSE compared to Val66Val homozygotes homozygotes (n = 37) following 20 min (p = 0.002) but not 10 min (p = 0.219) of stimulation. Moreover, Met carriers, but not Val/Val homozygotes, exhibited larger responses to TMS (p = 0.046) after 20 min atDCS, than following 10 min atDCS. On an individual level, two-step cluster analysis revealed a considerable degree of inter-individual variability, with under half of the total sample (42%) showing the expected potentiation of CSE in response to atDCS across both sessions. Intra-individual variability in response to different durations of atDCS was also apparent, with one-third of the total sample (34%) exhibiting LTP-like effects in one session but LTD-like effects in the other session. Both the inter-individual (p = 0.027) and intra-individual (p = 0.04) variability was associated with BDNF genotype. In older adults, the BDNF Val66Met polymorphism along with stimulation duration appears to play a role in modulating tDCS-induced motor cortex plasticity. The results may have implications for the design of NBS protocols for healthy and diseased aged populations. © 2015 Puri, Hinder, Fujiyama, Gomez, Carson and Summers.
- Authors: Puri, Rohan , Hinder, Mark , Fujiyama, Hakuei , Gomez, Rapson , Carson, Richard , Summers, Jeff
- Date: 2015
- Type: Text , Journal article
- Relation: Frontiers in Aging Neuroscience Vol. 7, no. JUN (2015), p. 1-10
- Full Text:
- Reviewed:
- Description: The brain derived neurotrophic factor (BDNF) Val66Met polymorphism and stimulation duration are thought to play an important role in modulating motor cortex plasticity induced by non-invasive brain stimulation (NBS). In the present study we sought to determine whether these factors interact or exert independent effects in older adults. Fifty-four healthy older adults (mean age = 66.85 years) underwent two counterbalanced sessions of 1.5 mA anodal transcranial direct current stimulation (atDCS), applied over left M1 for either 10 or 20 min. Single pulse transcranial magnetic stimulation (TMS) was used to assess corticospinal excitability (CSE) before and every 5 min for 30 min following atDCS. On a group level, there was an interaction between stimulation duration and BDNF genotype, with Met carriers (n = 13) showing greater post-intervention potentiation of CSE compared to Val66Val homozygotes homozygotes (n = 37) following 20 min (p = 0.002) but not 10 min (p = 0.219) of stimulation. Moreover, Met carriers, but not Val/Val homozygotes, exhibited larger responses to TMS (p = 0.046) after 20 min atDCS, than following 10 min atDCS. On an individual level, two-step cluster analysis revealed a considerable degree of inter-individual variability, with under half of the total sample (42%) showing the expected potentiation of CSE in response to atDCS across both sessions. Intra-individual variability in response to different durations of atDCS was also apparent, with one-third of the total sample (34%) exhibiting LTP-like effects in one session but LTD-like effects in the other session. Both the inter-individual (p = 0.027) and intra-individual (p = 0.04) variability was associated with BDNF genotype. In older adults, the BDNF Val66Met polymorphism along with stimulation duration appears to play a role in modulating tDCS-induced motor cortex plasticity. The results may have implications for the design of NBS protocols for healthy and diseased aged populations. © 2015 Puri, Hinder, Fujiyama, Gomez, Carson and Summers.
The shame and guilt scales of the Test of Self-Conscious Affect-Adolescent (TOSCA-A) : Psychometric properties for responses from children, and measurement invariance across children and adolescents
- Watson, Shaun, Gomez, Rapson, Gullone, Eleonora
- Authors: Watson, Shaun , Gomez, Rapson , Gullone, Eleonora
- Date: 2016
- Type: Text , Journal article
- Relation: Frontiers in Psychology Vol. 7, no. MAY (2016), p. 1-10
- Full Text:
- Reviewed:
- Description: This study examined various psychometric properties of the items comprising the shame and guilt scales of the Test of Self-Conscious Affect-Adolescent (TOSCA-A) in a group children between 8 and 11 years of age. A total of 699 children (367 females and 332 males) completed these scales, and also measures of depression and empathy. Confirmatory factor analysis (CFA) provided support for an oblique two-factor model, with the originally proposed shame and guilt items comprising shame and guilt factors, respectively. There was good internal consistency reliability for the shame and guilt scales, with omega coefficient values of 0.77 and 0.81 for shame and guilt, respectively. Also, shame correlated with depression symptoms positively (0.34, p < 0.001) and had no relation with empathy (-0.07, ns). Guilt correlated with depression symptoms negatively (-0.28, p < 0.001), and with empathy positively (0.13. p < 0.05). Thus there was support for the convergent and discriminant validity of the shame and guilt factors. Multiple-group CFA comparing this group of children with a separate group of adolescents (320 females and 242 males), based on the chi-square difference test, supported full metric invariance, the intercept invariance of 17 of the 30 shame and guilt items, and higher latent mean scores among children for both shame and guilt. The non-equivalency for intercepts and mean scores were of small effect sizes. Comparisons based on the difference in root mean squared error of approximation values supported full measurement invariance and no group difference for latent mean scores. The findings in the current study support the use of the TOSCA-A in children and the valid comparison of scores between children and adolescents, thereby opening up the possibility of evaluating change in the TOSCA-A shame and guilt factors over these developmental age groups. © 2016 Watson, Gomez and Gullone.
- Authors: Watson, Shaun , Gomez, Rapson , Gullone, Eleonora
- Date: 2016
- Type: Text , Journal article
- Relation: Frontiers in Psychology Vol. 7, no. MAY (2016), p. 1-10
- Full Text:
- Reviewed:
- Description: This study examined various psychometric properties of the items comprising the shame and guilt scales of the Test of Self-Conscious Affect-Adolescent (TOSCA-A) in a group children between 8 and 11 years of age. A total of 699 children (367 females and 332 males) completed these scales, and also measures of depression and empathy. Confirmatory factor analysis (CFA) provided support for an oblique two-factor model, with the originally proposed shame and guilt items comprising shame and guilt factors, respectively. There was good internal consistency reliability for the shame and guilt scales, with omega coefficient values of 0.77 and 0.81 for shame and guilt, respectively. Also, shame correlated with depression symptoms positively (0.34, p < 0.001) and had no relation with empathy (-0.07, ns). Guilt correlated with depression symptoms negatively (-0.28, p < 0.001), and with empathy positively (0.13. p < 0.05). Thus there was support for the convergent and discriminant validity of the shame and guilt factors. Multiple-group CFA comparing this group of children with a separate group of adolescents (320 females and 242 males), based on the chi-square difference test, supported full metric invariance, the intercept invariance of 17 of the 30 shame and guilt items, and higher latent mean scores among children for both shame and guilt. The non-equivalency for intercepts and mean scores were of small effect sizes. Comparisons based on the difference in root mean squared error of approximation values supported full measurement invariance and no group difference for latent mean scores. The findings in the current study support the use of the TOSCA-A in children and the valid comparison of scores between children and adolescents, thereby opening up the possibility of evaluating change in the TOSCA-A shame and guilt factors over these developmental age groups. © 2016 Watson, Gomez and Gullone.
A brief review of exercise, bipolar disorder, and mechanistic pathways
- Thomson, Daniel, Turner, Alyna, Lauder, Sue, Gigler, Margaret, Berk, Lesley, Singh, Ajeet, Pasco, Julie, Berk, Michael, Sylvia, Louisa
- Authors: Thomson, Daniel , Turner, Alyna , Lauder, Sue , Gigler, Margaret , Berk, Lesley , Singh, Ajeet , Pasco, Julie , Berk, Michael , Sylvia, Louisa
- Date: 2015
- Type: Text , Journal article , Review
- Relation: Frontiers in Psychology Vol. 6, no. (2015), p. 1-10
- Full Text:
- Reviewed:
- Description: Despite evidence that exercise has been found to be effective in the treatment of depression, it is unclear whether these data can be extrapolated to bipolar disorder. Available evidence for bipolar disorder is scant, with no existing randomized controlled trials having tested the impact of exercise on depressive, manic or hypomanic symptomatology. Although exercise is often recommended in bipolar disorder, this is based on extrapolation from the unipolar literature, theory and clinical expertise and not empirical evidence. In addition, there are currently no available empirical data on program variables, with practical implications on frequency, intensity and type of exercise derived from unipolar depression studies. The aim of the current paper is to explore the relationship between exercise and bipolar disorder and potential mechanistic pathways. Given the high rate of medical co-morbidities experienced by people with bipolar disorder, it is possible that exercise is a potentially useful and important intervention with regard to general health benefits; however, further research is required to elucidate the impact of exercise on mood symptomology. © 2015 Thomson, Turner, Lauder, Gigler, Berk, Singh, Pasco, Berk and Sylvia.
- Authors: Thomson, Daniel , Turner, Alyna , Lauder, Sue , Gigler, Margaret , Berk, Lesley , Singh, Ajeet , Pasco, Julie , Berk, Michael , Sylvia, Louisa
- Date: 2015
- Type: Text , Journal article , Review
- Relation: Frontiers in Psychology Vol. 6, no. (2015), p. 1-10
- Full Text:
- Reviewed:
- Description: Despite evidence that exercise has been found to be effective in the treatment of depression, it is unclear whether these data can be extrapolated to bipolar disorder. Available evidence for bipolar disorder is scant, with no existing randomized controlled trials having tested the impact of exercise on depressive, manic or hypomanic symptomatology. Although exercise is often recommended in bipolar disorder, this is based on extrapolation from the unipolar literature, theory and clinical expertise and not empirical evidence. In addition, there are currently no available empirical data on program variables, with practical implications on frequency, intensity and type of exercise derived from unipolar depression studies. The aim of the current paper is to explore the relationship between exercise and bipolar disorder and potential mechanistic pathways. Given the high rate of medical co-morbidities experienced by people with bipolar disorder, it is possible that exercise is a potentially useful and important intervention with regard to general health benefits; however, further research is required to elucidate the impact of exercise on mood symptomology. © 2015 Thomson, Turner, Lauder, Gigler, Berk, Singh, Pasco, Berk and Sylvia.
Renal denervation promotes atherosclerosis in hypertensive apolipoprotein E-Deficient mice infused with angiotensin II
- Wang, Yutang, Dinh, Tam, Nield, Alex, Krishna, Smriti, Denton, Kate, Golledge, Jonathan
- Authors: Wang, Yutang , Dinh, Tam , Nield, Alex , Krishna, Smriti , Denton, Kate , Golledge, Jonathan
- Date: 2017
- Type: Text , Journal article
- Relation: Frontiers in Physiology Vol. 8, no. (2017), p. 1-9
- Relation: http://purl.org/au-research/grants/nhmrc/1062671
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- Reviewed:
- Description: Objective: To determine the effect of renal denervation (RDN) on the severity of atherosclerosis and aortic aneurysm in hypertensive mice. Methods: Hypertension, atherosclerosis and aortic aneurysm were induced by subcutaneous infusion of angiotensin II (1 μg/kg/min) for 28 days in apolipoprotein E-deficient mice. RDN was conducted using combined surgical and local chemical denervation. The norepinephrine concentration in the kidney was measured by high-performance liquid chromatography. Blood pressure was measured by the tail-cuff method. Atherosclerosis was assessed by Sudan IV staining of the aortic arch. The aortic diameter was measured by the morphometric method. The mRNA expression of genes associated with atherosclerosis and aortic aneurysm were analyzed by quantitative PCR. Results: RDN decreased the median norepinephrine content in the kidney by 93.4% (n = 5-7, P = 0.003) 5 days after the procedure, indicating that the RDN procedure was successful. RDN decreased systolic blood pressure in apolipoprotein E-deficient mice. Mice that had RDN had more severe aortic arch atherosclerosis (median percentage of Sudan IV positive area: 13.2% in control mice, n = 12, and 25.4% in mice having RDN, n = 12, P = 0.028). The severity of the atherosclerosis was negatively correlated with the renal norepinephrine content (spearman r = -0.6557, P = 0.005). RDN did not affect the size of aortic aneurysms formed or the incidence of aortic rupture in mice receiving angiotensin II. RDN significantly increased the aortic mRNA expression of matrix metalloproteinase-2 (MMP-2). Conclusion: RDN promoted atherosclerosis in apolipoprotein E-deficient mice infused with angiotensin II associated with upregulation of MMP-2. The higher MMP-2 expression could be the results of the greater amount of atheroma in the RDN mice. The findings suggest further research is needed to assess potentially deleterious effects of RDN in patients. © 2017 Wang, Dinh, Nield, Krishna, Denton and Golledge.
- Authors: Wang, Yutang , Dinh, Tam , Nield, Alex , Krishna, Smriti , Denton, Kate , Golledge, Jonathan
- Date: 2017
- Type: Text , Journal article
- Relation: Frontiers in Physiology Vol. 8, no. (2017), p. 1-9
- Relation: http://purl.org/au-research/grants/nhmrc/1062671
- Full Text:
- Reviewed:
- Description: Objective: To determine the effect of renal denervation (RDN) on the severity of atherosclerosis and aortic aneurysm in hypertensive mice. Methods: Hypertension, atherosclerosis and aortic aneurysm were induced by subcutaneous infusion of angiotensin II (1 μg/kg/min) for 28 days in apolipoprotein E-deficient mice. RDN was conducted using combined surgical and local chemical denervation. The norepinephrine concentration in the kidney was measured by high-performance liquid chromatography. Blood pressure was measured by the tail-cuff method. Atherosclerosis was assessed by Sudan IV staining of the aortic arch. The aortic diameter was measured by the morphometric method. The mRNA expression of genes associated with atherosclerosis and aortic aneurysm were analyzed by quantitative PCR. Results: RDN decreased the median norepinephrine content in the kidney by 93.4% (n = 5-7, P = 0.003) 5 days after the procedure, indicating that the RDN procedure was successful. RDN decreased systolic blood pressure in apolipoprotein E-deficient mice. Mice that had RDN had more severe aortic arch atherosclerosis (median percentage of Sudan IV positive area: 13.2% in control mice, n = 12, and 25.4% in mice having RDN, n = 12, P = 0.028). The severity of the atherosclerosis was negatively correlated with the renal norepinephrine content (spearman r = -0.6557, P = 0.005). RDN did not affect the size of aortic aneurysms formed or the incidence of aortic rupture in mice receiving angiotensin II. RDN significantly increased the aortic mRNA expression of matrix metalloproteinase-2 (MMP-2). Conclusion: RDN promoted atherosclerosis in apolipoprotein E-deficient mice infused with angiotensin II associated with upregulation of MMP-2. The higher MMP-2 expression could be the results of the greater amount of atheroma in the RDN mice. The findings suggest further research is needed to assess potentially deleterious effects of RDN in patients. © 2017 Wang, Dinh, Nield, Krishna, Denton and Golledge.
The role of ion channels in microglial activation and proliferation - a complex interplay between ligand-gated ion channels, K+ channels, and intracellular Ca2+
- Stebbing, Martin, Cottee, Jennifer, Rana, Indrajeetsinh
- Authors: Stebbing, Martin , Cottee, Jennifer , Rana, Indrajeetsinh
- Date: 2015
- Type: Text , Journal article
- Relation: Frontiers in Immunology Vol. 6, no. OCT (2015), p. 1-7
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- Reviewed:
- Description: Microglia are often referred to as the immune cells of the brain. They are most definitely involved in immune responses to invading pathogens and inflammatory responses to tissue damage. However, recent results suggest microglia are vital for normal functioning of the brain. Neuroinflammation, as well as more subtle changes, in microglial function has been implicated in the pathogenesis of many brain diseases and disorders. Upon sensing alterations in their local environment, microglia change their shape and release factors that can modify the excitability of surrounding neurons. During neuroinflammation, microglia proliferate and release NO, reactive oxygen species, cytokines and chemokines. If inflammation resolves then their numbers normalize again via apoptosis. Microglia express a wide array of ion channels and different types are implicated in all of the cellular processes listed above. Modulation of microglial ion channels has shown great promise as a therapeutic strategy in several brain disorders. In this review, we discuss recent advances in our knowledge of microglial ion channels and their roles in responses of microglia to changes in the extracellular milieu. © 2015 Stebbing, Cottee and Rana.
- Authors: Stebbing, Martin , Cottee, Jennifer , Rana, Indrajeetsinh
- Date: 2015
- Type: Text , Journal article
- Relation: Frontiers in Immunology Vol. 6, no. OCT (2015), p. 1-7
- Full Text:
- Reviewed:
- Description: Microglia are often referred to as the immune cells of the brain. They are most definitely involved in immune responses to invading pathogens and inflammatory responses to tissue damage. However, recent results suggest microglia are vital for normal functioning of the brain. Neuroinflammation, as well as more subtle changes, in microglial function has been implicated in the pathogenesis of many brain diseases and disorders. Upon sensing alterations in their local environment, microglia change their shape and release factors that can modify the excitability of surrounding neurons. During neuroinflammation, microglia proliferate and release NO, reactive oxygen species, cytokines and chemokines. If inflammation resolves then their numbers normalize again via apoptosis. Microglia express a wide array of ion channels and different types are implicated in all of the cellular processes listed above. Modulation of microglial ion channels has shown great promise as a therapeutic strategy in several brain disorders. In this review, we discuss recent advances in our knowledge of microglial ion channels and their roles in responses of microglia to changes in the extracellular milieu. © 2015 Stebbing, Cottee and Rana.
Cannabis use and anxiety : Is stress the missing piece of the puzzle?
- Temple, Elizabeth, Driver, Matthew, Brown, Rhonda
- Authors: Temple, Elizabeth , Driver, Matthew , Brown, Rhonda
- Date: 2014
- Type: Text , Journal article
- Relation: Frontiers in Psychiatry Vol. 5, no. (2014), p. 1-13
- Full Text:
- Reviewed:
- Description: Objective: Comorbidity between anxiety and cannabis use is common yet the nature of the association between these conditions is not clear. Four theories were assessed, and a fifth hypothesis tested to determine if the misattribution of stress symptomology plays a role in the association between state-anxiety and cannabis. Methods: Three-hundred-sixteen participants ranging in age from 18 to 71 years completed a short online questionnaire asking about their history of cannabis use and symptoms of stress and anxiety. Results: Past and current cannabis users reported higher incidence of lifetime anxiety than participants who had never used cannabis; however, these groups did not differ in state-anxiety, stress, or age of onset of anxiety. State-anxiety and stress were not associated with frequency of cannabis use, but reported use to self-medicate for anxiety was positively associated with all three. Path analyses indicated two different associations between anxiety and cannabis use, pre-existing and high state-anxiety was associated with (i) higher average levels of intoxication and, in turn, acute anxiety responses to cannabis use; (ii) frequency of cannabis use via the mediating effects of stress and self-medication. Conclusion: None of the theories was fully supported by the findings. However, as cannabis users reporting self-medication for anxiety were found to be self-medicating stress symptomology, there was some support for the stress-misattribution hypothesis. With reported self-medication for anxiety being the strongest predictor of frequency of use, it is suggested that researchers, clinicians, and cannabis users pay greater attention to the overlap between stress and anxiety symptomology and the possible misinterpretation of these related but distinct conditions. © 2014 Temple, Driver and Brown.
- Authors: Temple, Elizabeth , Driver, Matthew , Brown, Rhonda
- Date: 2014
- Type: Text , Journal article
- Relation: Frontiers in Psychiatry Vol. 5, no. (2014), p. 1-13
- Full Text:
- Reviewed:
- Description: Objective: Comorbidity between anxiety and cannabis use is common yet the nature of the association between these conditions is not clear. Four theories were assessed, and a fifth hypothesis tested to determine if the misattribution of stress symptomology plays a role in the association between state-anxiety and cannabis. Methods: Three-hundred-sixteen participants ranging in age from 18 to 71 years completed a short online questionnaire asking about their history of cannabis use and symptoms of stress and anxiety. Results: Past and current cannabis users reported higher incidence of lifetime anxiety than participants who had never used cannabis; however, these groups did not differ in state-anxiety, stress, or age of onset of anxiety. State-anxiety and stress were not associated with frequency of cannabis use, but reported use to self-medicate for anxiety was positively associated with all three. Path analyses indicated two different associations between anxiety and cannabis use, pre-existing and high state-anxiety was associated with (i) higher average levels of intoxication and, in turn, acute anxiety responses to cannabis use; (ii) frequency of cannabis use via the mediating effects of stress and self-medication. Conclusion: None of the theories was fully supported by the findings. However, as cannabis users reporting self-medication for anxiety were found to be self-medicating stress symptomology, there was some support for the stress-misattribution hypothesis. With reported self-medication for anxiety being the strongest predictor of frequency of use, it is suggested that researchers, clinicians, and cannabis users pay greater attention to the overlap between stress and anxiety symptomology and the possible misinterpretation of these related but distinct conditions. © 2014 Temple, Driver and Brown.
- Lu, Lei, Robinson, Mark, Tan, Ying, Goonewardena, Kusal, Guo, Xinliang, Mareels, Iven, Oetomo, Denny
- Authors: Lu, Lei , Robinson, Mark , Tan, Ying , Goonewardena, Kusal , Guo, Xinliang , Mareels, Iven , Oetomo, Denny
- Date: 2020
- Type: Text , Journal article
- Relation: Frontiers in physiology Vol. 11, no. (2020), p. 541974-541974
- Full Text: false
- Reviewed:
- Description: A forward head and rounded shoulder posture is a poor posture that is widely seen in everyday life. It is known that sitting in such a poor posture with long hours will bring health issues such as muscle pain. However, it is not known whether sitting in this poor posture for a short period of time will affect human activities. This paper investigates the effects of a short-duration poor posture before some typical physical activities such as push-ups. The experiments are set up as follows. Fourteen male subjects are asked to do push-ups until fatigue with two surface electromyography (sEMG) at the upper limb. Two days later, they are asked to sit in this poor posture for 15 min with eight sEMG sensors located at given back muscles. Then they do the push-ups after the short-duration poor posture. The observations from the median frequency of sEMG signals at the upper limb indicate that the short-duration poor posture does affect the fatigue procedure of push-ups. A significant decreasing trend of the performance of push-ups is obtained after sitting in this poor posture. Such effects indicate that some parts of the back muscles indeed get fatigued with only 15 min sitting in this poor posture. By further investigating the time-frequency components of sEMG of back muscles, it is observed that the low and middle frequencies of sEMG signals from the infraspinatus muscle of the dominant side are demonstrated to be more prone to fatigue with the poor posture. Although this study focuses only on push-ups, similar experiments can be arranged for other physical exercises as well. This study provides new insights into the effect of a short-duration poor posture before physical activities. These insights can be used to guide athletes to pay attention to postures before physical activities to improve performance and reduce the risk of injury.
Single-session anodal tDCS with small-size stimulating electrodes over frontoparietal superficial sites does not affect motor sequence learning
- Hashemirad, Fahimeh, Fitzgerald, Paul, Zoghi, Maryam, Jaberzadeh, Shapour
- Authors: Hashemirad, Fahimeh , Fitzgerald, Paul , Zoghi, Maryam , Jaberzadeh, Shapour
- Date: 2017
- Type: Text , Journal article
- Relation: Frontiers in Human Neuroscience Vol. 11, no. (2017), p. 153-153
- Full Text:
- Reviewed:
- Description: Due to the potential of anodal transcranial direct current stimulation (a-tDCS) for enhancement of fine sequenced movements and increasing interest in achieving high level of fine movements in the trained and untrained hands especially at initial stage of learning, we designed this study to investigate whether the application of single-session a-tDCS with small-size stimulating electrodes over FPN sites, such as dorsolateral prefrontal cortex (DLPFC), primary motor cortex (M1) or posterior parietal cortex (PPC) could enhance sequence learning with the trained hand and these effects are transferred into the untrained hand or not. A total of 51 right-handed healthy participants were randomly assigned to one of the four stimulation groups: a-tDCS of left M1, DLPFC, PPC, or sham. Stimulation was applied for 20 min during a sequential visual isometric pinch task (SVIPT). Eight blocks of training using SVIPT were completed with the right hand during stimulation. Two blocks of sequence training with each hand were performed by participants as assessment blocks at three time points: baseline, 15 min and one day following the intervention. Behavioral outcomes including movement time, error rate and skill were assessed in all assessment blocks across three time points. We also measured corticospinal excitability, short-interval intracortical inhibition, and intracortical facilitation using single- and paired-pulse transcranial magnetic stimulation. The results indicated that the behavioral outcomes were significantly improved with the right trained hand, but this learning effect was not modulated by a-tDCS with small-size stimulating electrodes over the FPN. Transfer of learning into the untrained hand was observed in all four groups for movement time but not for the error rate or skill. Our results suggest that sequential learning in SVIPT and its transfer into the untrained hand were not sensitive to a single-session a-tDCS with small-size stimulating electrodes over left M1, DLPFC or PPC in young healthy participants.
- Authors: Hashemirad, Fahimeh , Fitzgerald, Paul , Zoghi, Maryam , Jaberzadeh, Shapour
- Date: 2017
- Type: Text , Journal article
- Relation: Frontiers in Human Neuroscience Vol. 11, no. (2017), p. 153-153
- Full Text:
- Reviewed:
- Description: Due to the potential of anodal transcranial direct current stimulation (a-tDCS) for enhancement of fine sequenced movements and increasing interest in achieving high level of fine movements in the trained and untrained hands especially at initial stage of learning, we designed this study to investigate whether the application of single-session a-tDCS with small-size stimulating electrodes over FPN sites, such as dorsolateral prefrontal cortex (DLPFC), primary motor cortex (M1) or posterior parietal cortex (PPC) could enhance sequence learning with the trained hand and these effects are transferred into the untrained hand or not. A total of 51 right-handed healthy participants were randomly assigned to one of the four stimulation groups: a-tDCS of left M1, DLPFC, PPC, or sham. Stimulation was applied for 20 min during a sequential visual isometric pinch task (SVIPT). Eight blocks of training using SVIPT were completed with the right hand during stimulation. Two blocks of sequence training with each hand were performed by participants as assessment blocks at three time points: baseline, 15 min and one day following the intervention. Behavioral outcomes including movement time, error rate and skill were assessed in all assessment blocks across three time points. We also measured corticospinal excitability, short-interval intracortical inhibition, and intracortical facilitation using single- and paired-pulse transcranial magnetic stimulation. The results indicated that the behavioral outcomes were significantly improved with the right trained hand, but this learning effect was not modulated by a-tDCS with small-size stimulating electrodes over the FPN. Transfer of learning into the untrained hand was observed in all four groups for movement time but not for the error rate or skill. Our results suggest that sequential learning in SVIPT and its transfer into the untrained hand were not sensitive to a single-session a-tDCS with small-size stimulating electrodes over left M1, DLPFC or PPC in young healthy participants.
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