Biology subjects

Fanning, J.

Publications and source records attributed to Fanning, J..

5 recordsLinked to original sources

bioRxiv2021

Desire and Craving ratings vary significantly for healthy alcohol consumers: Differences in semantic interpretation?

Craving is a central concept in alcohol, and other substance, research. Beginning in 1955 the World Health Organization outlined a working definition of the term to be used in research and clinical settings. However, the semantic interpretation of "craving" as a concept is not widely agreed upon. Since the publication of this first craving definition, a handful of studies have been conducted to investigate differences in operational definitions of "craving", and have demonstrated a lack of agreement between studies and across research subjects. With this background as evidence, our research group investigated, when left to their own semantic understanding of the terms, if regular alcohol consumers would rate craving for alcohol and desire for alcohol in similar ways using related descriptors. Thirty-nine healthy, non-binging regular alcohol consumers were studied across periods of their typical alcohol consumption and imposed alcohol abstinence, collecting ratings of desire and craving for alcohol approximately every two hours across the two experimental periods, and during neutral and alcohol related imagery viewing. Among these non-binging regular drinkers, ratings of desire and craving for alcohol are consistently different while drinking according to a persons typical routine or abstaining, throughout the day, and when viewing alcohol cue imagery.

neuroscience↗

bioRxiv2021

Differential momentary reports of stress and affect associated with alcohol consumption in middle-aged versus younger adults

ObjectiveStress is a motivator to consume alcohol, a well-documented relapse risk, and is known to differentially affect biological and psychological processes as people age. Because alcohol consumption is known to decrease stress and increase affect, this study examined differences in ratings of stress and affect across the day in middle-aged versus younger adults who regularly consumed alcohol. MethodsA sample of males and females including younger (n=17) and middle-aged (n=18) drinkers was studied across two experimental periods: a 3-day period of usual drinking and a 3-day period of abstinence from alcohol. We also measured resting levels of respiratory sinus arrhythmia (RSArest), since it is a well-documented biomarker of stress and known to decrease with age. Ecological momentary assessment (EMA) ratings across periods of normal drinking and abstinence were modeled using hierarchical regression to assess differences in stress and affect throughout days of abstinence and normal drinking between the two age groups. ResultsAs anticipated, middle-aged participants had lower RSArest than those who were younger. Our analyses showed that middle-aged adults experienced a significant reduction in stress following drinking while no such effect was observed in the younger adults. Although the middle-aged adults showed overall lower stress, generally they also expressed higher affect than younger adults. ConclusionsDespite the mitigating role of alcohol on stress in the middle-aged group and the fact that they had higher affect than the younger adults, their lower levels of RSArest and higher daily reports of stress could pose a risk for chronic alcohol consumption.

neuroscience↗

bioRxiv2021

Brain structure and function predict adherence to an exercise intervention in older adults

Individualized and precision medicine approaches to exercise for cognitive and brain health in aging have the potential to improve intervention efficacy. Predicting adherence to an exercise intervention in older adults prior to its commencement will allow for adaptive and optimized approaches that could save time (no need to demonstrate failure before changing course) and money (cost of de-implementing approaches that do not work for certain individuals) which ultimately could improve health outcomes (e.g., preventative medicine approaches prior to the onset of symptoms). Individual differences in brain structure and function in older adults are potential proxies of brain and brain reserve or maintenance and may provide strong predictions of adherence. We hypothesized that brain-based measures would predict adherence to a six-month randomized controlled trial of exercise in older adults, alone and in combination with psychosocial, cognitive and health measures. In 131 older adults (aged 65.79 {+/-} 4.65 years, 63% female) we found, using regularized elastic net regression within a nested cross-validation framework, that brain structure (cortical thickness and cortical surface area) in somatosensory, inferior temporal, and inferior frontal regions and functional connectivity (degree count) in primary information processing (somatosensory, visual), executive control, default, and attentional networks, predicted exercise adherence (R2 = 0.15, p < 0.001). Traditional survey and clinical measures such as gait and walking self-efficacy, biological sex and perceived stress also predicted adherence (R2 = 0.06, p = 0.001) but a combined multimodal model achieved the highest predictive strength (R2 = 0.22, p <0.001). Neuroimaging features alone can predict adherence to a structured group-based exercise intervention in older adults which suggests there is substantial utility of these measures for future research into precision medicine approaches. The best performing model contained multimodal features suggesting that each modality provided independent relevant information in the prediction of exercise adherence.

neuroscience↗

bioRxiv2021

Resting State Functional Connectivity Predicts Future Changes in Sedentary Behavior

Information about a persons available energy resources is integrated in daily behavioral choices that weigh motor costs against expected rewards. It has been posited that humans have an innate attraction towards effort minimization and that executive control is required to overcome this prepotent disposition. With sedentary behaviors increasing at the cost of millions of dollars spent in health care and productivity losses due to physical inactivity-related deaths, understanding the predictors of sedentary behaviors will improve future intervention development and precision medicine approaches. In 64 healthy older adults participating in a 6-month aerobic exercise intervention, we use neuroimaging (resting state functional connectivity), baseline measures of executive function and accelerometer measures of time spent sedentary to predict future changes in objectively measured time spent sedentary in daily life. Using cross-validation and bootstrap resampling, our results demonstrate that functional connectivity between 1) the anterior cingulate cortex and the supplementary motor area and 2) the right anterior insula and the left temporoparietal/temporooccipital junction, predict changes in time spent sedentary, whereas baseline cognitive, behavioral and demographic measures do not. Previous research has shown activation in and between the anterior cingulate and supplementary motor area as well as in the right anterior insula during effort avoidance and tasks that integrate motor costs and reward benefits in effort-based decision making. Our results add important knowledge toward understanding mechanistic associations underlying complex sedentary behaviors.

neuroscience↗

bioRxiv2020

The role of conidia in the dispersal of Ascochyta rabiei

Ascochyta rabiei asexual spores (conidia) were assumed to spread over short distances ([~]10 m) in a combination of rain and strong wind. The potential distance of conidial spread was investigated in three rainfall and three sprinkler irrigation events. Chickpea trap plants were distributed at the distances of 0, 10, 25, 50 and 75 m from infected chickpea plots before scheduled irrigation and forecast rainfall events. Trap plants were transferred to a controlled temperature room (20 {degrees}C) for 48 h (100% humidity) after being exposed in the field for 2-6 days for rainfall events, and for one day for irrigation events. After a 48 h incubation period, trap plants were transferred to a glasshouse (20 {degrees}C) to allow lesion development. Lesions on all plant parts were counted after two weeks, which gave an estimate of the number of conidia released and the distance travelled. Trap plants at all distances were infected in all sprinkler irrigation and rainfall events. The highest number of lesions on trap plants were recorded closest to the infected plots - the numbers decreased as the distance from the infected plots increased. There was a positive relationship between the amount of rainfall and the number of lesions recorded. A generalised additive model was developed that efficiently described spatial patterns of conidial spread. With further development, the model can be used to predict the spread of A. rabiei. This is the first systematic study to show that conidia distribute A. rabiei over longer distances than previously reported.

plant biology↗