Barriers to initiating and maintaining participation in parkrun.

Interventions that increase population physical activity are required to promote health and wellbeing. parkrun delivers community-based, 5 km events worldwide yet 43% who register never participate in a parkrun event. This research had two objectives; i) explore the demographics of people who register for parkrun in United Kingdom, Australia, Ireland, and don't initiate or maintain participation ii) understand the barriers to participating in parkrun amongst these people. Mandatory data at parkrun registration provided demographic characteristics of parkrun registrants. A bespoke online survey distributed across the three countries captured the reasons for not participating or only participating once. Of 680,255 parkrun registrants between 2017 and 19, 293,542 (43%) did not participate in any parkrun events and 147,148 (22%) only participated in one parkrun event. Females, 16-34 years and physically inactive were more likely to not participate or not return to parkrun. Inconvenient start time was the most frequently reported barrier to participating, with females more likely than males to report the psychological barrier of feeling too unfit to participate. Co-creating strategies with and for people living with a chronic disease, women, young adults, and physically inactive people, could increase physical activity participation within parkrun.

Gender inclusive sporting environments: the proportion of women in non-player roles over recent years.

BACKGROUND: Throughout the ecosystem of sport, women have been and continue to be underrepresented at all levels compared to men. The capacity of community-level sport is heavily reliant on the many non-player roles including governance, as well as administration, coaching and officiating. Recently there has been increased attention to improving the gender balance in sport. The aim of this study is to investigate the proportions of women engaged in non-playing roles in sport (2016-2018). METHODS: This study involved secondary analysis of the AusPlay survey, a national population survey, funded by Sport Australia. This study utilised data from people aged 15-years or older about their involvement in non-playing roles in sport, and their demographic data. Survey respondents were asked "During the last 12 months, have you been involved with any sports in a nonplaying role, such as official, coach, referee, administrator, etc?" Analysis of non-player role responses focussed specifically on the top four non-player role categories; coach, official, administrator and manager. Frequency analysis concentrated on the distribution of men and women involvement in a non-player capacity for the three years, with detailed analysis of the most recent year (2018). RESULTS: In this study of 61,578 Australians there was a higher proportion of men in non-player roles in sport compared to women, across each of the three years (2018: men 55 %, women 46 %). Involvement of women in coaching increased significantly from 38 % to 2016 to 44 % in 2018 (p < 0.001). The proportion of women involved in administration roles significantly decreased from a peak of 51 % in 2017 to 46 % in 2018 (p < 0.001). CONCLUSIONS: Aligned with strategic policy and investment strategies, there are gradual increased representation of women in non-playing sport, coaching roles. Women are still underrepresented in terms of coaches, officials and administrators, but are more likely to be managers. It is recommended that there is continued mentoring, identification and emphasising of female role models, and further strategies to increase female presence in non-playing roles. We recommend that future research, in line with appropriate gender and cultural-change theories, investigates and discusses the progress of gender equality throughout playing and non-playing role in sport.

Reducing financial barriers through the implementation of voucher incentives to promote children's participation in community sport in Australia.

BACKGROUND: Participation in organised sport and physical activity contributes to health-enhancing levels of leisure time physical activity. In Australia, 58% of children aged 0-14 years participated at least once a week in October 2015 - December 2017. To overcome the frequently cited cost barrier, sports voucher incentives have been widely implemented across Australia. METHOD: The financial value of jurisdictional vouchers and the National median financial value were used to calculate the proportion of total annual expenditure on children's participation in sport supported by sports vouchers. Participation rates using AusPlay data were estimated by age, sex and socio-economic index (SEIFA) at state and national level for children aged 0-14 years. RESULTS: Five States and Territories implemented sports vouchers from 2011 to 2018, with a median value of AU$150. Nationally, median annual expenditure for children's sport participation was AU$447 (IQR $194.2-936), with 27% reported expenditure supported by a sports voucher. The proportion of financial support from sports vouchers increased considerably with social disadvantage, rising to over 60% of total expenditure in the most disadvantaged populations. CONCLUSIONS: Socio-economic status was associated with sports-related expenditure and sports participation amongst children. Sport vouchers should target children in the most disadvantaged areas to promote participation in organised sport and physical activity.

Intra-gastric balloon as an adjunct to lifestyle support in severely obese adolescents; impact on weight, physical activity, cardiorespiratory fitness and psychosocial well-being.

BACKGROUND: Severe adolescent obesity (body mass index (BMI) >99.6th centile) is a significant public health challenge. Current non-invasive treatments, including community-based lifestyle interventions, are often of limited effectiveness in this population, with NICE guidelines suggesting the use of bariatric surgery as the last line of treatment. Health professionals are understandably reluctant to commission bariatric surgery and as an alternative, the use of an intra-gastric balloon as an adjunct to a lifestyle programme might offer a reversible, potentially safer and less invasive option. OBJECTIVES: Explore the use of an intra-gastric balloon as an adjunct to a lifestyle support programme, to promote weight loss in severely obese adolescents. Outcomes included weight loss, waist and hip measurements, psychosocial outcomes including health-related quality of life (HRQoL) and physical self perceptions, physical activity and cardiorespiratory fitness. METHOD: Non-randomised pilot study. RESULTS: Twelve severely obese adolescents (5 males, 7 females; mean age 15 years; BMI >3.5 s.d.; puberty stage 4 or more) and their families were recruited. Mean weight loss at 12 months (n=9) was 3.05 kg±14.69; d=0.002, P=0.550, and a BMI Z-score (n=12) change of 0.2 s.d.; d=0.7, P=0.002 was observed at 6 months with a large effect, but was not sustained at 12 months (mean change 0.1 s.d.; d=0.3, P=0.146). At 24 months (n=10), there was a weight gain from baseline of +9.9 kg±1.21 (d=0.4; P=0.433). Adolescent and parent HRQoL scores exceeded the minimal clinical important difference between baseline and 12 months for all domains but showed some decline at 24 months. CONCLUSION: An intra-gastric balloon as an adjunct to a lifestyle support programme represents a safe and well-tolerated treatment approach in severely obese adolescents, with short-term effects on weight change. Improvements in psychosocial health, physical activity and cardiorespiratory fitness were maintained at 12 months, with varying results at 24 months.

Kidney Exchange to Overcome Financial Barriers to Kidney Transplantation.

Organ shortage is the major limitation to kidney transplantation in the developed world. Conversely, millions of patients in the developing world with end-stage renal disease die because they cannot afford renal replacement therapy-even when willing living kidney donors exist. This juxtaposition between countries with funds but no available kidneys and those with available kidneys but no funds prompts us to propose an exchange program using each nation's unique assets. Our proposal leverages the cost savings achieved through earlier transplantation over dialysis to fund the cost of kidney exchange between developed-world patient-donor pairs with immunological barriers and developing-world patient-donor pairs with financial barriers. By making developed-world health care available to impoverished patients in the developing world, we replace unethical transplant tourism with global kidney exchange-a modality equally benefitting rich and poor. We report the 1-year experience of an initial Filipino pair, whose recipient was transplanted in the United states with an American donor's kidney at no cost to him. The Filipino donor donated to an American in the United States through a kidney exchange chain. Follow-up care and medications in the Philippines were supported by funds from the United States. We show that the logistical obstacles in this approach, although considerable, are surmountable.

Historical Matching Strategies in Kidney Paired Donation: The 7-Year Evolution of a Web-Based Virtual Matching System.

Failure to convert computer-identified possible kidney paired donation (KPD) exchanges into transplants has prohibited KPD from reaching its full potential. This study analyzes the progress of exchanges in moving from "offers" to completed transplants. Offers were divided into individual segments called 1-way transplants in order to calculate success rates. From 2007 to 2014, the Alliance for Paired Donation performed 243 transplants, 31 in collaboration with other KPD registries and 194 independently. Sixty-one of 194 independent transplants (31.4%) occurred via cycles, while the remaining 133 (68.6%) resulted from nonsimultaneous extended altruistic donor (NEAD) chains. Thirteen of 35 (37.1%) NEAD chains with at least three NEAD segments accounted for 68% of chain transplants (8.6 tx/chain). The "offer" and 1-way success rates were 21.9 and 15.5%, respectively. Three reasons for failure were found that could be prospectively prevented by changes in protocol or software: positive laboratory crossmatch (28%), transplant center declined donor (17%) and pair transplanted outside APD (14%). Performing a root cause analysis on failures in moving from offer to transplant has allowed the APD to improve protocols and software. These changes have improved the success rate and the number of transplants performed per year.

Onset of optic nerve conduction and synaptic potentials in superior colliculus of fetal rats studied in vitro.

This article describes the onset of electrical excitability and synaptic transmission in the retinocollicular pathway of the fetal and early postnatal rat, utilizing a novel in vitro preparation. Although the optic nerve is visible in embryonic day (E) 14 brain, its stimulation produced no response in the superior colliculus (SC) until E16 when a low voltage simple negative wave was evoked. At E17 these potentials were blocked rapidly, completely, and reversibly when choline was substituted for sodium or with the addition of cobalt ions. In the course of establishing the block with either of the above agents the latency of response increased, indicating an action on axonal transmission. By E20 the collicular evoked potential showed a short followed by a longer latency wave. The latter was blocked by the glutamate antagonist kynurenic acid, with latency unaffected. Further examination of potentials with the addition of glutamatergic receptor subtype blockers aminophosphonopentanoic acid (APV) and 6-cyano-7-nitroquinoxaline-2,3-dione/6,7-dinitroquinoxaline- 2,3-dione (CNQX/DNQX) showed a clear abolition of the elicited potentials by E20 and older. Thus, fetal rat optic nerve fibers are capable of conduction in response to electrical stimulation as soon as they reach the SC at E16. Both sodium and calcium are involved. GABA-mediated modulation of axonal conduction is evident by E18. Glutaminergic synaptic transmission is established by E20. The timetable of fetal onset of capability to conduct and support synaptic transmission in the retinocollicular pathway is earlier than had previously been reported in vivo in the rat in which the superior colliculus neurones are said not to be driven by the optic nerve until 6 days post natal. This has relevance to the possible role of impulse activity in development of the pathway.

Long-term plasticity at excitatory synapses on aspinous interneurons in area CA1 lacks synaptic specificity.

The synaptic specificity of long-term potentiation (LTP) was examined at synapses formed on aspinous dendrites of interneurons whose somata were located in the pyramidal cell layer of hippocampal area CA1. Intracellular recordings from slices prepared from rats were used to monitor excitatory postsynaptic potentials (EPSPs) elicited by extracellular stimulation in stratum radiatum. Two synaptic inputs were evoked at 0.5 Hz by stimulating axons adjacent to stratum pyramidale and s. lacunosum-moleculare. After obtaining baseline recordings (>/=10 min), one of the EPSPs was conditioned. The protocol involved tetanic stimulation, sometimes combined with somatic depolarization. Low-frequency stimulation of the two pathways was then resumed and EPSPs were recorded for <30 min. We observed both homosynaptic and heterosynaptic changes in synaptic strength. LTP and long-term depression (LTD) were seen in both pathways and all possible combinations of changes in the two EPSPs were observed, including heterosynaptic LTP associated with either homosynaptic LTP or LTD. Intracellular 1,2-bis (2-aminophenoxy)-ethane-N,N,N',N'-tetraacetic acid (10 mM) abolished alterations in synaptic strength. When axons in s. radiatum synapse onto a spiny pyramidal cell, synaptic specificity of LTP is preserved. However the results obtained from aspinous interneurons show that synaptic specificity of LTP is lost. These results are consistent with the hypothesis that spines provide postsynaptic mechanism(s) for conferring specificity to LTP.

Zinc induces hyperexcitability in the hippocampus.

The effects of zinc on neuronal excitability in rodent hippocampal slices were examined. In a paired-pulse protocol, the second population spike increased appreciably in the presence of zinc, whereas the first spike and the size of both population excitatory post-synaptic potentials remained unaffected. Changes in the second population spike produced by zinc were most pronounced when the afferents were stimulated with paired-pulses separated by 8-40 ms. The magnitude of altered excitability increased with the concentration of zinc in the perfusate. A long exposure to zinc in physiological concentration caused an epileptiform discharge followed by a period of depression. The effects of zinc could be mimicked with 1-3 microM bicuculline. We conclude that the integrity of the hippocampal inhibitory system is particularly vulnerable to zinc.

Effects of cholinergic agonists on two non-pyramidal cell types in rat hippocampal slices.

In the hippocampus, pyramidal cells (PCs) are not the only cell type sensitive to cholinergic stimulation. Two non-pyramidal cell types from animals as young as 8 days demonstrated clear, direct responses to application of cholinergic agonists. These cholinergic actions are excitatory, mostly blocked by muscarinic antagonists, and persist under conditions which block synaptic transmission (TTX, low Ca2+/high Mg2+). Cholinergic agonists may affect different conductances in interneurons than in PCs, sometimes resulting in rapid depolarization. Demonstration of direct excitatory cholinergic effects on inhibitory interneurons supports the view that cholinergically-evoked hyperpolarizations in PCs are due to local circuit interactions.

Construction of a synthetic gene for an R-plasmid-encoded dihydrofolate reductase and studies on the role of the N-terminus in the protein.

R67 dihydrofolate reductase (DHFR) is a novel protein that provides clinical resistance to the antibacterial drug trimethoprim. The crystal structure of a dimeric form of R67 DHFR indicates the first 16 amino acids are disordered [Matthews et al. (1986) Biochemistry 25, 4194-4204]. To investigate whether these amino acids are necessary for protein function, the first 16 N-terminal residues have been cleaved off by chymotrypsin. The truncated protein is fully active with kcat = 1.3 s-1, Km(NADPH) = 3.0 microM, and Km(dihydrofolate) = 5.8 microM. This result suggests the functional core of the protein resides in the beta-barrel structure defined by residues 27-78. To study this protein further, synthetic genes coding for full-length and truncated R67 DHFRs were constructed. Surprisingly, the gene coding for truncated R67 DHFR does not produce protein in vivo or confer trimethoprim resistance upon Escherichia coli. Therefore, the relative stabilities of native and truncated R67 DHFR were investigated by equilibrium unfolding studies. Unfolding of dimeric native R67 DHFR is protein concentration dependent and can be described by a two-state model involving native dimer and unfolded monomer. Using absorbance, fluorescence, and circular dichroism techniques, an average delta GH2O of 13.9 kcal mol-1 is found for native R67 DHFR. In contrast, an average delta GH2O of 11.3 kcal mol-1 is observed for truncated R67 DHFR. These results indicate native R67 DHFR is 2.6 kcal mol-1 more stable than truncated protein. This stability difference may be part of the reason why protein from the truncated gene is not found in vivo in E. coli.

Effects of cholinergic agonists on immature rat hippocampal neurons.

We have investigated the effects of acetylcholine (ACh) and the cholinergic agonist carbachol on several cell types in the developing rat hippocampus. Pyramidal cells were responsive to cholinergic applications on the first day examined (postnatal day 2), indicating that postsynaptic cholinoceptivity develops early, perhaps before functional cholinergic innervation is present. These drugs, which induce a membrane depolarization and a conductance decrease in mature pyramidal cells, had similar effects (both magnitude and pharmacology) on most immature neurons. However, a minority of cells in immature tissue exhibited decreased input resistance (Rin) during the cholinergic-induced depolarization. This response is likely a product of cholinergic action on local circuit neurons: non-pyramidal-type cells from animals as young as 8 days demonstrated excitatory responses to application of cholinergic agonists. The study revealed a number of other features of immature cells which may have functional significance. Lucifer yellow injections showed significant dye coupling among CA3 (but not CA1) pyramidal cells in immature tissue, suggesting close metabolic and/or electrotonic coupling between those cells during development. Mature CA3 cells showed less dye coupling, but increased anomalous rectification, and longer time constant. Developmental changes in intrinsic cell properties, coupled to alterations in local circuit interactions, may alter tissue responsiveness to neurotransmitters such as acetylcholine, even if the receptor-mediated drug action remains stable.

Nicotine exerts differential effects on different CA1 hippocampal cell types.

The effects of (-) nicotine hydrogen tartrate (NHT) were examined on several cell types in the CA1 region of rat hippocampus. The results indicate that nicotine may have a preferential net inhibitory effect on basket cells and an excitatory effect on oriens/alveus interneurons. The resultant effects of nicotine on pyramidal cells may thus be a product of complex local circuit interactions.