Search

The Gorgon CO2 project (The Gorgon Project is operated by Chevron Australia and is a joint venture of the Australian subsidiaries of Chevron (47.3%), ExxonMobil (25%), Shell (25%), Osaka Gas (1.25%), Tokyo Gas (1%) and JERA (0.417%)) is the world’s largest operational Carbon Capture and Storage (CCS) project dedicated to greenhouse gas abatement. Since starting injection in 2019 it has successfully sequestered more than 7.5 million tonnes of CO2 equivalent (as at 31 January 2023). A comprehensive surveillance program – including reservoir pressure monitoring, 4D seismic, microseismic monitoring, distributed temperature and acoustic sensing, and InSAR surface displacement measurement – provides a wealth of data for developing history-matched static, dynamic and geomechanical models that are instrumental in the operation and development planning of the field. In comparison to modelling of conventional hydrocarbon reservoirs, in which maximising production and ultimate recovery are typically the focus, developing and selecting a suite of representative CCS models requires consideration of an additional set of factors. These factors include modelling CO2 plume movement, managing reservoir pressure at key locations and accommodating geomechanical constraints. This paper will explore these differences, and how the various sources of surveillance data have been integrated into the modelling process to better understand and predict the dynamic behaviour of the Dupuy reservoir.

To investigate whether participation in sport during the developmental stages of life is associated with cardiorespiratory fitness (CRF) in adulthood.Observational longitudinal study.Participants were Generation 2 of the Raine Study. Questionnaires related to participation in sport were administered at ages 5, 8, 10, 14 and 17 years. These data were used to develop sex-specific trajectories of sports participation: (for males) Consistent Participators, Drop-Outs and Joiners; and (females) Consistent Participators, Non-Participators and Drop-Outs. At age 28.3 ± 0.6 years, participants completed a graded maximal exercise test (i.e. V̇O402 participants n = 231 (57.5%) male, n = 171 (42.5%) female were included in the study. In males, Consistent Participators (all p 0.001) and Joiners (p 0.050) had greater fitness than Drop-Outs. In females, Consistent Participators had greater fitness than Non-Participators (p 0.050), but there were no significant differences in fitness between Consistent Participators and Drop-Outs (p 0.050) or Non-Participators and Drop-Outs (p 0.050).Participation in sport during childhood and adolescence is associated with greater fitness in adulthood, compared to individuals who never participate or those that cease participation in adolescence. A simple dichotomous question regarding sports participation over the childhood and adolescent period can be implemented to predict better fitness outcomes in young adulthood. Childhood and adolescence could be an opportune stage in life for parents, schools and governments to facilitate participation in sport and prevent drop out, as it may have an impact on long term risk reduction, with associated health and economic benefits.

PRECIS Higher physical working capacity (PWC) at age 17 was associated with thicker peripapillary retinal nerve fiber layer (pRNFL) at age 20, suggesting a mechanistic link between cardiovascular fitness and neuroretinal integrity. PURPOSE Physical activity and cardiovascular fitness have been linked with lower odds of developing glaucoma. We tested the hypothesis that early beneficial effects of physical activity and cardiovascular fitness can be observed by measuring the pRNFL thickness in young healthy adults. METHODS The Raine Study is a longitudinal study that has followed a cohort since before their births in 1989-1992. Parent-reported physical activity was collected between 8 and 17 years, and latent class analysis was used to identify the participants' physical activity trajectories. At the 20-year follow-up (participants' mean age=20.1±0.4 y), participants' metabolic equivalent of task-minutes/week was determined using self-reported physical activity data. Participants' PWC was assessed at the 14- and 17-year follow-ups to estimate their level of cardiovascular fitness. An eye examination, which included spectral-domain optical coherence tomography imaging, was conducted at the 20-year follow-up for 1344 participants. RESULTS Parent-reported or participant-reported physical activity was not associated with pRNFL thickness. However, higher PWC at 17 years was associated with thicker pRNFL globally [by 0.3 µm; 95% confidence interval (CI)=0.2-0.6; P

Although child mortality has decreased over the last few decades, around 4,500 infants and children die in the UK every year, many of whom require palliative care. There is, however, little evidence on paediatric end-of-life care services. The current National Institute for Health and Care Excellence (NICE) guidance provides recommendations about what should be offered, but these are based on low quality evidence. The ENHANCE study aims to identify and investigate the different models of existing end-of-life care provision for infants, children, and young people in the UK, including an assessment of the outcomes and experiences for children and parents, and the cost implications to families and healthcare providers.This mixed methods study will use three linked workstreams and a cross-cutting health economics theme to examine end-of-life care models in three exemplar clinical settings: infant, children and young adult cancer services (PTCs), paediatric intensive care units (PICUs), and neonatal units (NNUs).Workstream 1 (WS1) will survey current practice in each setting and will result in an outline of the different models of care used. WS2 is a qualitative comparison of the experiences of staff, parents and patients across the different models identified. WS3 is a quantitative assessment of the outcomes, resource use and costs across the different models identified.Results from this study will contribute to an understanding of how end-of-life care can provide the greatest benefit for children at the end of their lives. It will also allow us to understand the likely benefits of additional funding in end-of-life care in terms of patient outcomes.

PURPOSE: Endothelial dysfunction is an early and integral atherogenic event. Interventions that improve endothelial function also reduce cardiovascular risk. Due largely to the direct hemodynamic effects of repetitive exercise on the artery wall, exercise training has shown to enhance endothelial function. Land walking (LW) and water walking (WW) induce distinct hemodynamic responses, so the comparison of their effects provides an approach to study shear stress effects on endothelial function. We hypothesized that LW and WW training would have different effects on peripheral artery endothelial function. METHODS: Fifty-one sedentary, older (age = 61.9 ± 6.6 yr, 23.5% male) individuals were randomized into one of three groups: control (n = 16), or one of two exercise groups consisting of 3 × 50 min supervised and individually tailored walking sessions per week for 24 consecutive weeks, performed either on LW (n = 17) or on WW (n = 18). Brachial artery endothelial function (flow-mediated dilation) and smooth muscle cell function (glyceryl trinitrate administration) were tested in all participants before (week 0) and after (week 24) the intervention. RESULTS: Differences were apparent in flow-mediated dilation change between the LW group (week 0, 5.39% ± 0.71%, to week 24, 7.77% ± 0.78%; P = 0.009) and the control group (week 0, 5.87% ± 0.73%, to week 24, 5.78% ± 0.78%). No differences in artery dilation response were found after glyceryl trinitrate administration (all P > 0.05). CONCLUSION: This study suggests that 6-month center-based LW may be superior to WW in terms of improvement in arterial endothelial function in older sedentary individuals.

Objectives Increasing physical activity is a priority worldwide, including for older adults who may have difficulty performing traditional forms of exercise, and for whom retention of muscle mass is an important consideration. Water-based exercise may provide an alternative if benefits are comparable. We compared the impact on body composition of 24-week water- versus land-walking interventions in healthy but inactive older adults. Design Randomised, controlled trial. Methods 72 participants (62.5 ± 6.8 yr) were randomised to a land-walking (LW), water-walking (WW) or control (C) group in a supervised centre-based program. The exercise groups trained 3 times/week at matched intensity (%HRR), increasing from 40–45% to 55–65% heart rate reserve (HRR). Height, weight, body mass index (BMI), waist and hip girths were recorded; dual X-ray absorptiometry (DXA) provided fat and lean tissue masses. Participants were re-assessed 24 weeks after completion of the intervention. Results There were no significant changes in body mass or BMI following either exercise protocol, however central adiposity was reduced in both exercise groups, and the WW group increased lower limb lean mass. These benefits did not persist over the follow-up period. Conclusions Exercise can confer beneficial effects on body composition which are not evident when examining weight or BMI. Both WW and LW improved body composition. Water walking can be recommended as an exercise strategy for this age group due to its beneficial effects on body composition which are similar to, or exceed, those associated with land-walking. For benefits to persist, it appears that exercise needs to be maintained.

The pathophysiology and time course of impairment in cutaneous microcirculatory function and structure remain poorly understood in people with diabetes, partly due to the lack of investigational tools capable of directly imaging and quantifying the microvasculature in vivo. We applied a new optical coherence tomography (OCT) technique, at rest and during reactive hyperemia (RH), to assess the skin microvasculature in people with diabetes with foot ulcers (DFU, n = 13), those with diabetes without ulcers (DNU, n = 9), and matched healthy controls (CON, n = 13). OCT images were obtained from the dorsal part of the foot at rest and following 5 min of local ischemia induced by inflating a cuff around the thigh at suprasystolic level (220 mmHg). One-way ANOVA was used to compare the OCT-derived parameters (diameter, speed, flow rate, and density) at rest and in response to RH, with repeated-measures two-way ANOVA performed to analyze main and interaction effects between groups. Data are means ± SD. At rest, microvascular diameter in the DFU (84.89 ± 14.84 µm) group was higher than CON (71.25 ± 7.6 µm, P = 0.012) and DNU (71.33 ± 12.04 µm, P = 0.019) group. Speed in DFU (65.56 ± 4.80 µm/s, P = 0.002) and DNU (63.22 ± 4.35 µm/s, P = 0.050) were higher than CON (59.58 ± 3.02 µm/s). Microvascular density in DFU (22.23 ± 13.8%) was higher than in CON (9.83 ± 2.94%, P = 0.008), but not than in the DNU group (14.8 ± 10.98%, P = 0.119). All OCT-derived parameters were significantly increased in response to RH in the CON group (all P < 0.01) and DNU group (all P < 0.05). Significant increase in the DFU group was observed in speed ( P = 0.031) and density ( P = 0.018). The change in density was lowest in the DFU group (44 ± 34.1%) compared with CON (199.2 ± 117.5%, P = 0.005) and DNU (148.1 ± 98.4, P = 0.054). This study proves that noninvasive OCT microvascular imaging is feasible in people with diabetes, provides powerful new physiological insights, and can distinguish between healthy individuals and patients with diabetes with distinct disease severity.

Endothelial dysfunction is an early and integral atherogenic event. Interventions that improve endothelial function also reduce cardiovascular risk. Due largely to the direct hemodynamic effects of repetitive exercise on the artery wall, exercise training has shown to enhance endothelial function. Land walking (LW) and water walking (WW) induce distinct hemodynamic responses, so the comparison of their effects provides an approach to study shear stress effects on endothelial function. We hypothesized that LW and WW training would have different effects on peripheral artery endothelial function.Fifty-one sedentary, older (age = 61.9 ± 6.6 yr, 23.5% male) individuals were randomized into one of three groups: control (n = 16), or one of two exercise groups consisting of 3 × 50 min supervised and individually tailored walking sessions per week for 24 consecutive weeks, performed either on LW (n = 17) or on WW (n = 18). Brachial artery endothelial function (flow-mediated dilation) and smooth muscle cell function (glyceryl trinitrate administration) were tested in all participants before (week 0) and after (week 24) the intervention.Differences were apparent in flow-mediated dilation change between the LW group (week 0, 5.39% ± 0.71%, to week 24, 7.77% ± 0.78%; P = 0.009) and the control group (week 0, 5.87% ± 0.73%, to week 24, 5.78% ± 0.78%). No differences in artery dilation response were found after glyceryl trinitrate administration (all P0.05).This study suggests that 6-month center-based LW may be superior to WW in terms of improvement in arterial endothelial function in older sedentary individuals.

Optical coherence tomography (OCT) is a novel high-resolution imaging technique capable of visualizing in vivo structures at a resolution of ~10 μm. We have developed specialized OCT-based approaches that quantify diameter, speed, and flow rate in human cutaneous microvessels. In this study, we hypothesized that OCT-based microvascular assessments would possess comparable levels of reliability when compared with those derived using conventional laser Doppler flowmetry (LDF).Speckle decorrelation images (OCT) and red blood cell flux (LDF) measures were collected from adjacent forearm skin locations on 2 d (48 h apart), at baseline, and after a 30-min rapid local heating protocol (30°C-44°C) in eight healthy young individuals. OCT postprocessing quantified cutaneous microvascular diameter, speed, flow rate, and density (vessel recruitment) within a region of interest, and data were compared between days.Forearm skin LDF (13 ± 4 to 182 ± 31 AU, P0.05) and OCT-derived diameter (41.8 ± 6.6 vs 64.5 ± 6.9 μm), speed (68.4 ± 9.5 vs 89.0 ± 7.3 μm·s), flow rate (145.0 ± 60.6 vs 485 ± 132 pL·s), and density (9.9% ± 4.9% vs 45.4% ± 5.9%) increased in response to local heating. The average OCT-derived microvascular flow response (pL·s) to heating (234% increase) was lower (P0.05) than the LDF-derived change (AU) (1360% increase). Pearson correlation was significant for between-day local heating responses in terms of OCT flow (r = 0.93, P0.01), but not LDF (P = 0.49). Bland-Altman analysis revealed that between-day baseline OCT-derived flow rates were less variable than LDF-derived flux.Our findings indicate that OCT, which directly visualizes human microvessels, not only allows microvascular quantification of diameter, speed, flow rate, and vessel recruitment but also provides outputs that are highly reproducible. OCT is a promising novel approach that enables a comprehensive assessment of cutaneous microvascular structure and function in humans.

Purpose The purpose of this paper is to provide an analysis of the market abuse regulation to determine whether the general assumption that it has made little difference to the pre-existing UK law on market abuse is accurate. In particular, the potential impact on compliance and behaviour in financial services firms and those who potentially receive inside information is considered. Design/methodology/approach The methodology adopted is a combination of critical analysis and black letter law utilised to determine the content and potential impact of the market abuse regulation. A process of discovery made more important by the limited assistance given by the European Securities and Markets Authority and the Financial Conduct Authority in terms of the guidance and definitions they have provided. Findings The new Regulation has a wider definition of insider dealing than under the previous law, has a wider application in terms of the financial instruments that it applies to, has triggered significant new compliance and disclosure requirements and it also extends the law to new markets. Research limitations/implications There are limitations in that the relevant regulatory bodies, ESMA and the FCA have made little effort to clarify how they interpret the new Regulation. This is a serious problem because in the case of the FCA, their view will impact on the approach they will take in future enforcement actions. Practical implications This paper provides the first real analysis of the market abuse regulation’s effect and shows that, if carefully analysed in context, it has a significant impact on firms in the financial services sector and those engaged in activities which can put them in receipt of inside information. It will cause an increase in relevant compliance and has significant cost implications for affected firms. Social implications This is not really relevant here. There will be necessary changes to compliance procedures. Originality/value The originality stems from the fact that there appears to be little else published which has engaged in a sustained analysis of the impact and effect of the EU market abuse regulation on the UK’s financial markets and those other firms who receive inside information.

Research has found that both compassion for others (CfO) and personal sense of uniqueness (PSU) are positively associated with subjective well-being (SWB). We conducted two studies, one with an emerging adult sample (N = 470), and the other with another emerging adult sample (N = 300) and a middle-aged adult sample (N = 169), investigating whether PSU mediated the relationship between CfO and SWB. In addition to utilizing different age groups for each study, the Satisfaction with Life Scale and the Positive Affect Negative Affect Schedule were used as a measure of SWB for Study 1 and 2, respectively. The proposed mediation model was supported within both studies: PSU was a significant mediator of the relationship between CfO and both components of SWB in emerging adults and the affective component of SWB in middle-aged adults. The implications of the findings and suggestions for future research are highlighted.

Displaying compassion for others (CFO) and utilizing friendship maintenance (FM) behaviors are positively associated with happiness. Two studies investigated FM as a mediator of the relationship between CFO and happiness (Study 1: N = 273; Study 2: N = 368). FM mediated the CFO-Happiness relationship in both studies regardless of the way happiness was measured. Although women had higher scores on both CFO and FM, the model was supported for both genders. The implications of the findings are discussed and suggestions for future research are provided.

Evidence-based guidelines recommend exercise therapy for patients with chronic heart failure (CHF). Such patients have increased atherothrombotic risk. Exercise can transiently increase platelet activation and reactivity and decrease vascular function in healthy participants, although data in CHF are scant. Eccentric (ECC) cycling is a novel exercise modality that may be particularly suited to patients with CHF, but the acute impacts of ECC cycling on platelet and vascular function are currently unknown. Our null hypothesis was that ECC and concentric (CON) cycling, performed at matched external workloads, would not induce changes in platelet or vascular function in patients with CHF. Eleven patients with heart failure with reduced ejection fraction (HFrEF) took part in discrete bouts of ECC and CON cycling. Before and immediately after exercise, vascular function was assessed by measuring diameter and flow-mediated dilation (FMD) of the brachial artery. Platelet function was measured by the flow cytometric determination of glycoprotein IIb/IIIa activation and granule exocytosis in the presence and absence of platelet agonists. ECC cycling increased baseline artery diameter (pre: 4.0 ± 0.8 mm vs. post: 4.2 ± 0.7 mm; P = 0.04) and decreased FMD%. When changes in baseline artery diameter were accounted for, the decrease in FMD post-ECC cycling was no longer significant. No changes were apparent after CON. Neither ECC nor CON cycling resulted in changes to any platelet-function measures (all P > 0.05). These results suggest that both ECC and CON cycling, at a moderate intensity and short duration, can be performed by patients with HFrEF without detrimental impacts on vascular or platelet function. NEW & NOTEWORTHY This is the first evidence to indicate that eccentric (ECC) cycling can be performed relatively safely by patients with chronic heart failure (CHF), as it did not result in impaired vascular or platelet function compared with conventional cycling. This is important, as acute exercise can transiently increase atherothrombotic risk, and ECC cycling is a novel exercise modality that may be particularly suited to patients with CHF.

INTRODUCTION: Chronic heart failure (CHF) is characterized by dyspnea and poor exercise tolerance, which decreases aerobic capacity (V˙O2peak), a measure strongly correlated with quality of life and mortality. In healthy populations, eccentric (ECC) cycling can be performed at a lower oxygen demand for matched workload, compared to concentric (CON) cycling, but few studies have previously investigated ECC cycling in CHF. We hypothesized that, when matched for external workload (Watts), an ECC cycling bout would be performed at a lower cardiorespiratory load (V˙O2) than CON in patients with CHF. METHODS: Eleven CHF patients (10 males) with impaired left ventricular systolic function (ejection fraction 31±12%) completed a CON V˙O2peak test, with the subsequent ECC and CON protocols set at 70% of individual maximal CON power (Watts). Oxygen consumption (V˙O2), respiratory exchange ratio (RER), minute ventilation (V˙E), heart rate (HR) and rate pressure product (RPP) were compared between conditions. RESULTS: ECC was performed at a lower V˙O2 (12.3±1.3 vs. 14.1±0.8 mL.kgmin, P=0.01), RER (0.92±0.02 vs. 0.96±0.01, P=0.01) and V˙E (36.5±4.4 vs. 40.2±2.0 L/min, P=0.04) in comparison to CON, despite both conditions being performed at matched workloads. Heart rate (101±5 vs. 96±1 bpm; P=0.06) and RPP (13,539±788 vs. 11,911±227 bpm.mmHg, P=0.15) were not significantly different between conditions. CONCLUSION: When matched for external workload, ECC cycling can be performed with a lower oxygen demand than CON in patients with CHF. Eccentric cycling is a promising modality for cardiac rehabilitation in severely deconditioned patients with CHF.

Increases in arterial carbon dioxide tension (hypercapnia) elicit potent vasodilation of cerebral arterioles. Recent studies have also reported vasodilation of the internal carotid artery during hypercapnia, but the mechanism(s) mediating this extracranial vasoreactivity are unknown. Hypercapnia increases carotid shear stress, a known stimulus to vasodilation in other conduit arteries. To explore the hypothesis that shear stress contributes to hypercapnic internal carotid dilation in humans, temporal changes in internal and common carotid shear rate and diameter, along with changes in middle cerebral artery velocity, were simultaneously assessed in 18 subjects at rest and during hypercapnia (6% carbon dioxide). Middle cerebral artery velocity increased significantly (69±10–103±17 cm/s; P P P P r =0.68; P

Five studies ( N = 5,150) relying on an exhaustive procedure addressed whether volunteer bias (VB) exists in friendship research among emerging adults (EAs). Consistently, the studies showed that women are more willing than men to participate in research on same-sex best friendship (SSBF). Studies 2 through 5 showed that friendship duration is not related to volunteering. Studies 3 and 4 showed that the friendships of volunteers were higher in positive friendship experiences compared to nonvolunteers. Finally, Study 5 showed that a significant portion of nonvolunteers ended up participating in research on SSBF. VB in research on friendship is an artifact that presents a concern for the generalizability and validity of findings relative to the friendship experiences of EAs. Recruitment strategies that could alleviate this problem are discussed.

Emerging adults share the positive events in their lives with their friends, a process that is related to higher levels of happiness when they perceive their friends’ responses as more positive and less negative. What might explain this association? The four studies (N = 2997) in this research tested the proposal that positive friendship experiences mediate the relationship between perceived responses to capitalization attempts (PRCA) and happiness. Study 1 showed that same-sex friendship quality mediated the relationship between PRCA and happiness. Study 2 supported the model for cross-sex friendships. Study 3 tested the generalizability of the model for the immediate social network of emerging adults and showed that the model was only applicable to best friendships. Study 4 documented that satisfaction of basic psychological needs in a same-sex friendship was another mediator of the PRCA-happiness link. Although the friendship experiences and PRCA scores of women were higher compared to men in every study, the associations of PRCA with friendship experiences and happiness were generally similar and the model was supported for both men and women. The implications of the findings were discussed and suggestions for future research were provided.

Adoptive transfer of tumor infiltrating lymphocytes (TIL) has generated objective clinical responses in patients with advanced metastatic cancers. Therapeutic exploitation of neoantigens as targets can potentially lead to safer and more effective treatment modalities with reduced toxicities. The Achilles Therapeutics trial NCT03517917 enabled the acquisition of matched tumor specimens and peripheral blood samples from patients undergoing routine surgery and facilitated the development of the proprietary VELOSTM manufacturing process, generating a personalized clonal neoantigen specific T cell product. An in-depth characterization of T cells expanded with the VELOSTM process was performed and compared to a standard TIL product. Samples were obtained from patients with primary NSCLC or metastatic melanoma. TIL were expanded from tumor fragments after dissection in the presence of IL-2. Peptide pools corresponding to the clonal mutations that were identified using the PELEUSTM bioinformatics platform were used to pulse dendritic cells (DC) generated from peripheral blood monocytes from each patient. Clonal neoantigen specific T cells (cNeT) were expanded using the VELOSTM process by co-culture of TIL with the peptide-pulsed autologous DC. As a comparison, TIL were expanded with a rapid expansion protocol (REP-TIL) in the presence of allogeneic feeders, anti-CD3 antibody and high-dose IL-2. Intracellular cytokine staining was performed following rechallenge with individual peptide pools encoding the clonal mutations. Single peptide reactivities were identified using ELISPOT and extended flow cytometric analysis of markers associated with T cell fitness or dysfunction was performed to phenotypically characterize the cNeT, TIL and REP-TIL. Analysis of the immune cell composition showed that cNeT, TIL and REP-TIL have similar CD3+ T cell content (median cNeT 90.2%, TIL 87.3%, REP-TIL 95%, n=6) and are composed of CD4+ and CD8+ T cells (median CD4:CD8 ratio- cNeT 11.1, TIL 2.03 and REP-TIL 4.7, n=6). cNeT showed superior clonal neoantigen specificity compared to TIL or REP-TIL. The proportion of CD3+ T cells responding to clonal neoantigen rechallenge was increased in cNeT (median 24.3%) compared to TIL (median 0.6%) and REP-TIL (median 1.8%) (n=5). The VELOSTM process incorporating the PELEUSTM platform for prediction of clonal neoantigens generates T cell products enriched for clonal neoantigen reactivities and superior phenotypic characteristics compared to conventional TIL. The VELOSTM process is currently being used to manufacture cNeT for two first-in-human studies including NSCLC and melanoma patients (NCT04032847, NCT03997474). Ethical approval: The samples for the study were collected under an ethically approved protocol (NCT03517917). Citation Format: Eleni Kotsiou, Tie Zheng Hou, Joseph Robinson, Sonal Varsani, Theres Oakes, Pablo D. Becker, Shreenal Patel, Jennine Mootien, Andrew Craig, Jane Robertson, Edward Samuel, James Reading, Lyra Del Rosario, Andrew Haynes, Samra Turajlic, Farah Islam, David Lawrence, Mariam Jamal-Hanjani, Martin Foster, Sergio A. Quezada, Katy Newton. Next generation clonal neoantigen targeting T cells, generated using the PELEUSTM bioinformatics platform and the VELOSTM manufacturing method show superior reactivity and phenotypic characteristics than classical TIL products [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 875.

Platelet activation, including the formation of monocyte platelet aggregates (MPAs), contributes to atherosclerosis, thrombus formation, and acute coronary syndromes. Regular participation in exercise can lower cardiovascular risk, but little is known regarding the impact of exercise training on platelet function. We investigated the effect of 6 mo of walking exercise on platelet function in sedentary older adults without significant cardiovascular disease. Twenty-seven participants were randomly allocated to 6 mo of either: no-exercise ( n = 13) or 3 × 50 min/wk of supervised center-based walking ( n = 14). Circulating and agonist-induced MPAs were assessed using flow cytometry before [ month 0 (0M)] and after [ month 6 (6M)] the intervention. Circulating MPAs increased from 0M (3.7 ± 1.0%) to 6M (4.7 ± 1.6%) in the no-exercise group ( P = 0.009), whereas a nonsignificant decrease was observed in the walking group (0M 4.3 ± 1.7 vs. 6M 3.7 ± 1.2 %, P = 0.052). The change in MPAs between groups was significant ( P = 0.001). There were no differences between groups in platelet responses to agonists across the interventions (all P > 0.05). Collectively, these data suggest that the absence of regular exercise may increase MPAs, which are cellular mediators involved in atherosclerosis, while regular walking inhibits such increases. The thrombotic function of platelets appears to be relatively unaltered by exercise training. This study provides novel data related to the cardioprotective effects associated with participation in exercise.NEW & NOTEWORTHY Monocyte-platelet aggregates contribute to atherosclerosis and exercise can lower cardiovascular risk. This is the first study to discover that a lack of regular physical activity is associated with increased monocyte-platelet aggregates over a 6-mo intervention period. In contrast, walking exercise inhibits increased monocyte-platelet aggregates in the circulation. This study highlights a novel pathway by which regular participation in exercise exerts its cardioprotective effects.