Electronic energy transfer in synthetic polymers : a reinvestigation

Imperial Users onl

Experiences influencing walking football initiation in 55-75 year-old adults

Adults aged 55 and older are least likely to play sport. Despite research suggesting this population experiences physical and psychological benefits when doing so, limited research focuses on older adult sport initiation, especially in “adapted sports” such as walking football. The aim of this study was to explore initiation experiences of walking football players between 55 and 75 years old. Semistructured interviews took place with 17 older adults playing walking football for 6 months minimum ( Mage = 64). Inductive analysis revealed six higher order themes representing preinitiation influences. Eight further higher order themes were found, relating to positive and negative experiences during initiation. Fundamental influences preinitiation included previous sporting experiences and values and perceptions. Emergent positive experiences during initiation included mental development and social connections. Findings highlight important individual and social influences when initiating walking football, which should be considered when encouraging 55- to 75-year-old adults to play adapted sport. Policy and practice recommendations are discussed

Biological control of Leptosphaeria maculans on Brassica napus and quantification of the microbes in planta using qPCR

Brassica napus is a commercially important crop worldwide and its use is quickly increasing due to its beneficial oil products and biofuel demands. Yield can be lost through infection by a fungal pathogen, Leptosphaeria maculans, the causal agent of stem canker (blackleg). An early indication of the presence of stem canker is a lesion (leaf spot) on the cotyledons or early leaves. The leaf spot stage of the disease was used in this work to ascertain if biological control agents applied both individually and in combination decreased the lesion area and also to quantify the amount of L. maculans DNA present using quantitative polymerase chain reaction (qPCR). The natural production of antibiotics by some bacteria is a commonly found form of antagonistic biological control. Bacillus amyloliquefaciens and Pseudomonas chlororaphis spp. aureofaciens 30.84 evaluated in this work both produce antibiotics and were assayed for their ability to provide control of Leptosphaeria maculans. Known active strains and field isolates of Bacillus and Pseudomonas were tested as potential biocontrol agents in vitro and then used in in planta assays. The in planta assays using bacterial isolates applied individually indicated that all the bacteria gave statistically significant control of L. maculans at the leaf spot stage. Those isolates with highest activity were further evaluated in combination, to determine if improved control of leaf spot occurred. Firstly, however, it was important to confirm the two bacteria would be compatible and antibiotics would be produced. To this aim, an in vitro assay using mutant Chromobacterium violaceum confirmed Pseudomonas chlororaphis spp. aureofaciens upregulated antibiotic production using acyl-homoserine lactones, signalling molecules. Consequently, it was vital that the Bacillus applied with it did not produce lactonase which would denature these molecules. PCR was used to confirm the enzyme was not present. It was, however, shown using in planta assays that combinations of Bacillus and Pseudomonas did not halt the infection or growth of L. maculans, but appeared to lead to increased lesion size. Colonisation of the cotyledons by the bacterial biological control agents applied onto the cotyledons was monitored by washing recovery, serial dilution, plating and colony counting along with qPCR of the DNA. All bacteria colonised successfully when applied individually. However, the populations decreased from the quantity at time zero when they were applied in combination, indicating they were unable to colonise the cotyledons successfully under those circumstances. To quantify Leptosphaeria infection, the concentration of ergosterol, a fungal sterol, was quantified to measure the colonisation of cotyledons. Concentrations were assessed using high performance liquid chromatography (HPLC). This assay was not successful no free ergosterol could be detected. This was probably due to L. maculans either having small amounts of ergosterol in its cell membranes, or having most of the ergosterol esterfied and unsuitable for quantification using this method. Polymerase chain reaction (PCR) was used to ascertain the presence of fungal hyphae within asymptomatic regions of cotyledons. It was found that the fungal DNA was detected within all areas of the cotyledon irrespective of whether the leaf spot could be seen. This result highlights the unreliability of the common method of visually assessing the presence and/or severity of L. maculans infection using leaf spot area. To monitor the populations of bacteria and the fungus in real time, DNA was extracted from the cotyledons and quantified using quantitative PCR (qPCR). The amount of L. maculans DNA isolated decreased when the BCAs were applied individually, and increased when the BCAs were applied in combination (when compared with the amount isolated from the control cotyledons). These results confirmed earlier, non-molecular assessments. To provide a benchmark for biocontrol activity, fungicides used in the control of leaf spot on oilseed rape were tested under the standard experimental conditions. Whilst control was obtained, it was not as effective as when used in the field, probably due to the formulations being optimised for field conditions. Fungicides targeted at wheat pathogens were also tested for control against L. maculans. Field application rates of these fungicides were not successful, as all damaged the epidermis of the cotyledon, resulting in death of the plant. Application of ¼ field rate still induced epidermal damage in all cotyledons except those sprayed with Q8Y78 (now called Refinzar®), where a necrotic lesion could be seen without pycnidia, at day 15 after inoculation

Walking football initiation and maintenance in older adults: a mixed-methods investigation

For older adults, physical activity (PA) is important to maintain a healthy lifestyle, and benefits include higher mobility and less healthcare needs (Age UK, 2018; Guzman-Castillo et al., 2017; Hambrook et al., 2020). Despite this, there are still a large number of older adults in the United Kingdom (UK) who are inactive (Sport England, 2020a), and research suggests few older adults maintain PA long-term (Kendrick et al., 2018; Van Der Deijl et al., 2014). Interventions to increase PA in older adults include sport, the benefits of which include managing mental health conditions, and reporting less sedentary behaviour in older adulthood (Eime et al., 2010; Gayman et al., 2017). Adapted sports such as walking football have also gained popularity (Lloyd, 2019), and understanding the experiences of those participating could inform design of accessible sport interventions to increase levels of older adult PA. A mixed-methods programme of research was undertaken. Studies one and two explored initiation and maintenance experiences of 55-75 year-old walking football players. Influences related to initiation of walking football included sporting identity, player values, and empowering players to cognitively and socially develop in older age. Influences related to maintenance of walking football included awareness of walking football benefits, positive walking football culture and availability of maintenance resources. Informed by study one and two findings, an empirically grounded survey was developed in study three to investigate differences in walking football initiation and maintenance influences, across key respondent characteristics in 50-75 year-old adults (chapter six). Further analysis investigated what characteristics and influences contribute to players returning to walking football after the Coronavirus-19 pandemic. Analysis found significant differences in social influences in initiation and maintenance across the number of health conditions. Regression analyses found walking football culture and maintenance resources (e.g. scheduling sessions) during maintenance contributed to the intention to continue playing after Coronavirus-19 pandemic restrictions were eased. Findings highlight the complex nature of older adult walking football participation, but show support for encouraging social interactions in those with health conditions, and creating a positive walking football culture and encouraging older adults to increase maintenance resources, in order to continue walking football play. The thesis provides club, coach and sporting body recommendations, and recommends that future research focuses on exploring the walking football culture in more detail, and the implementation of maintenance resources in aiding older adults to successfully maintain the sport

Biological control of Leptosphaeria maculans on Brassica napus and quantification of the microbes in planta using qPCR

Brassica napus is a commercially important crop worldwide and its use is quickly increasing due to its beneficial oil products and biofuel demands. Yield can be lost through infection by a fungal pathogen, Leptosphaeria maculans, the causal agent of stem canker (blackleg). An early indication of the presence of stem canker is a lesion (leaf spot) on the cotyledons or early leaves. The leaf spot stage of the disease was used in this work to ascertain if biological control agents applied both individually and in combination decreased the lesion area and also to quantify the amount of L. maculans DNA present using quantitative polymerase chain reaction (qPCR). The natural production of antibiotics by some bacteria is a commonly found form of antagonistic biological control. Bacillus amyloliquefaciens and Pseudomonas chlororaphis spp. aureofaciens 30.84 evaluated in this work both produce antibiotics and were assayed for their ability to provide control of Leptosphaeria maculans. Known active strains and field isolates of Bacillus and Pseudomonas were tested as potential biocontrol agents in vitro and then used in in planta assays. The in planta assays using bacterial isolates applied individually indicated that all the bacteria gave statistically significant control of L. maculans at the leaf spot stage. Those isolates with highest activity were further evaluated in combination, to determine if improved control of leaf spot occurred. Firstly, however, it was important to confirm the two bacteria would be compatible and antibiotics would be produced. To this aim, an in vitro assay using mutant Chromobacterium violaceum confirmed Pseudomonas chlororaphis spp. aureofaciens upregulated antibiotic production using acyl-homoserine lactones, signalling molecules. Consequently, it was vital that the Bacillus applied with it did not produce lactonase which would denature these molecules. PCR was used to confirm the enzyme was not present. It was, however, shown using in planta assays that combinations of Bacillus and Pseudomonas did not halt the infection or growth of L. maculans, but appeared to lead to increased lesion size. Colonisation of the cotyledons by the bacterial biological control agents applied onto the cotyledons was monitored by washing recovery, serial dilution, plating and colony counting along with qPCR of the DNA. All bacteria colonised successfully when applied individually. However, the populations decreased from the quantity at time zero when they were applied in combination, indicating they were unable to colonise the cotyledons successfully under those circumstances. To quantify Leptosphaeria infection, the concentration of ergosterol, a fungal sterol, was quantified to measure the colonisation of cotyledons. Concentrations were assessed using high performance liquid chromatography (HPLC). This assay was not successful no free ergosterol could be detected. This was probably due to L. maculans either having small amounts of ergosterol in its cell membranes, or having most of the ergosterol esterfied and unsuitable for quantification using this method. Polymerase chain reaction (PCR) was used to ascertain the presence of fungal hyphae within asymptomatic regions of cotyledons. It was found that the fungal DNA was detected within all areas of the cotyledon irrespective of whether the leaf spot could be seen. This result highlights the unreliability of the common method of visually assessing the presence and/or severity of L. maculans infection using leaf spot area. To monitor the populations of bacteria and the fungus in real time, DNA was extracted from the cotyledons and quantified using quantitative PCR (qPCR). The amount of L. maculans DNA isolated decreased when the BCAs were applied individually, and increased when the BCAs were applied in combination (when compared with the amount isolated from the control cotyledons). These results confirmed earlier, non-molecular assessments. To provide a benchmark for biocontrol activity, fungicides used in the control of leaf spot on oilseed rape were tested under the standard experimental conditions. Whilst control was obtained, it was not as effective as when used in the field, probably due to the formulations being optimised for field conditions. Fungicides targeted at wheat pathogens were also tested for control against L. maculans. Field application rates of these fungicides were not successful, as all damaged the epidermis of the cotyledon, resulting in death of the plant. Application of ¼ field rate still induced epidermal damage in all cotyledons except those sprayed with Q8Y78 (now called Refinzar®), where a necrotic lesion could be seen without pycnidia, at day 15 after inoculation

Onset of Mild Cognitive Impairment in Parkinson Disease

Objective: Characterize the onset and timing of cognitive decline in Parkinson disease (PD) from the first recognizable stage of cognitively symptomatic PD-mild cognitive impairment (PD-MCI) to PD dementia (PDD). Thirty-nine participants progressed from PD to PDD and 25 remained cognitively normal. Methods: Bayesian-estimated disease-state models described the onset of an individual’s cognitive decline across 12 subtests with a change point. Results: Subtests measuring working memory, visuospatial processing ability, and crystalized memory changed significantly 3 to 5 years before their first nonzero Clinical Dementia Rating and progressively worsened from PD to PD-MCI to PDD. Crystalized memory deficits were the hallmark feature of imminent conversion of cognitive status. Episodic memory tasks were not sensitive to onset of PD-MCI. For cognitively intact PD, all 12 subtests showed modest linear decline without evidence of a change point. Conclusions: Longitudinal disease-state models support a prodromal dementia stage (PD-MCI) marked by early declines in working memory and visuospatial processing beginning 5 years before clinical diagnosis of PDD. Cognitive declines in PD affect motor ability (bradykinesia), working memory, and processing speed (bradyphrenia) resulting in PD-MCI where visuospatial imagery and memory retrieval deficits manifest before eventual development of overt dementia. Tests of episodic memory may not be sufficient to detect and quantify cognitive decline in PD

Cerebrospinal Fluid α-Synuclein Predicts Cognitive Decline in Parkinson Disease Progression in the DATATOP Cohort

Most patients with Parkinson disease (PD) develop both cognitive and motor impairment, and biomarkers for progression are urgently needed. Although α-synuclein is altered in cerebrospinal fluid of patients with PD, it is not known whether it predicts motor or cognitive deterioration. We examined clinical data and α-synuclein in >300 unmedicated patients with PD who participated in the deprenyl and tocopherol antioxidative therapy of parkinsonism (DATATOP) study, with up to 8 years of follow-up. Longitudinal measures of motor and cognitive function were studied before (phase 1) and during (phase 2) levodopa therapy; cerebrospinal fluid was collected at the beginning of each phase. Correlations and linear mixed models were used to assess α-synuclein association with disease severity and prediction of progression in the subsequent follow-up period. Despite decreasing α-synuclein (phase 1 to phase 2 change of −0.05 ± 0.21 log-transformed values, P < 0.001), no correlations were observed between α-synuclein and motor symptoms. Longitudinally, lower α-synuclein predicted better preservation of cognitive function by several measures [Selective Reminding Test total recall α-synuclein × time interaction effect coefficient, −0.12 (P = 0.037); delayed recall, −0.05 (P = 0.002); New Dot Test, −0.03 (P = 0.002)]. Thus, α-synuclein, although not clinically useful for motor progression, might predict cognitive decline, and future longitudinal studies should include this outcome for further validation

Differences in older adult walking football initiation and maintenance influences across respondent characteristics: A cross-sectional survey

Despite health benefits gained from physical activity and sport participation, older adults are less likely to be active. This study investigates what influences 50–75-year-olds (N=439) to initiate and maintain walking football, across gender, socioeconomic status, number of health conditions and physical activity level. It also considers relationships between participant characteristics and influences, and intentions to play after a forced break (COVID-19). Results of a UK online cross-sectional survey found those with two or more health conditions rated social influences significantly higher in initiation and maintenance, than participants with no health conditions. Multiple regression analysis found a positive walking football culture and perceived use of maintenance resources contributed significantly to intentions to return to play after COVID-19 restrictions eased. Practitioners should consider providing opportunities for social connection, foster a positive walking football culture, and encourage players to utilise maintenance resources (e.g., scheduling sessions) in older adult walking football sessions. Keywords: behaviour change, soccer, physical activity, survey research, older adult