The Seasonal Prevalence and Impact of Emerging Infectious Diseases on Virginia Salamander Populations

Undergraduate Theoretica

An exploration of the relationship between cardiovascular health, lifestyle factors and platelet function.

Introduction Platelets are small, anucleate, cells which travel as resting discoid fragments in the blood circulation. Upon contact with an injured blood vessel, they prevent blood loss through processes of adhesion, activation and aggregation. Platelets play a central role in cardiovascular disease (CVD), both in the development of atherosclerosis and in the development of acute thrombotic events. CVD risk factors can be classed as modifiable or non-modifiable. This thesis focuses on the effect of the modifiable risk factors (physical inactivity, overweight/obesity and low cardiorespiratory fitness (CRF)) on platelet function. We investigate the role of acute exercise on platelet function, and the impact of CRF on platelet responses to acute exercise. We also explore the role of microRNA (miRNA), a subset of small non-coding RNA, in regulating platelet function in response to physical inactivity. Hypothesis Physical inactivity, overweight/obesity and low CRF adversely impact platelet function. miRNA expression could influence and modulate the platelet function response to physical inactivity. Results We performed a cross-sectional study to investigate the relationship between platelet function and lifestyle factors. High platelet counts and plateletcrit were associated with less favourable cardiovascular risk profiles, in particular with measures of overweight. Platelet adhesion was significantly increased in subjects with an overweight BMI compared to those with a healthy weight BMI. Acute strenuous aerobic exercise resulted in increased platelet adhesion and aggregation in adults and adolescents. This increase was more pronounced in those with a low CRF, particularly in adolescent subjects. Using a Dry Immersion (DI) model, we investigated the effect of acute physical inactivity on platelet function in 12 healthy males. Three days of DI resulted in significant increases in platelet count, plateletcrit, platelet adhesion, aggregation, and an elevation of platelet reactivity index (PRI) and microvesicle concentration. We identified 15 cardiovascular and inflammatory protein biomarkers whose expression levels were altered after physical inactivity. We also identified a set of 22 ‘physical inactivity’ related miRNA, which have potential targets involved in pathways associated with platelet function. Conclusion Modifiable CVD risk factors of overweight/obesity and physical inactivity elicit a prothrombotic platelet profile. CRF levels affect the platelet response to acute exercise, suggesting that habitual physical activity influences platelet function. miRNA expression can influence and modulate the platelet function response to physical inactivity by negative regulation of gene expression and could act as markers of megakaryocyte epigenetic drift

An Affordance-Based Methodology for Package Design

The term affordance describes an object\u27s utilitarian function or actionable possibilities. Product designers have taken great interest in the concept of affordances because of the bridge they provide relating to design, the interpretation of design and, ultimately, functionality in the hands of consumers. These concepts have been widely studied and applied in the field of psychology but have had limited formal application to packaging design and evaluation. We believe that the concepts related to affordances will reveal novel opportunities for packaging innovation. To catalyse this, presented work had the following objectives: (a) to propose a method by which packaging designers can purposefully consider affordances during the design process; (b) to explain this method in the context of a packaging-related case study; and (c) to measure the effect on package usability when an affordance-based design approach is employed

Measuring the effect of affordances on a crash cart medicine packaging

Abstract: In the United States, most drugs stored in crash carts of emergency rooms are packaged in folding cartons with opening mechanisms that involve pressing and tearing the bottom of the package. Anecdotal evidence and a previous study conducted by the research team suggest that these packages are counterintuitive for lay users. The concept of affordances, how design features communicate actionable possibilities, can be applied to improve the usability of packaging. In order to measure the effect of individual design features and previous experience on opening time and error frequency during first opening attempt, a commercially available package for epinephrine was redesigned and tested with two panels of participants; 33 lay users and 17 healthcare providers. Each experiment was conducted as a randomized complete block design with three factors: location of opening mechanism (top or bottom), type of opening mechanism (press-in or tab), and colour contrast in opening area (with and without). By crossing all possible conditions (2x2x2), eight different folding carton designs resulted. Each participant was treated as a block and presented all eight designs in a random order. Participants stood behind a counter of a fixed height and completed eight opening tasks in a lab facility (lay users) and an emergency room (healthcare providers). They were instructed to imagine an emergency scenario where they needed to remove all contents from each package as quickly as possible. Results show that colour contrast had no significant effect on opening time, having a tab significantly reduces time to open. More specifically, tabs cued the user as to the correct end containing the opening feature regardless of it was positioned on the top or bottom of the package. When there was no tab, then having the opening at the top resulted in a significant reduction in time to open, compared to having the opening at the bottom. In an analysis comparing the eight designs, the actual commercial packages ranked as the worst designs in terms of opening time and error frequency. Findings have critical implications for designing packages that are more usable and for eliminating errors during product use

Platelets: Functional Biomarkers of Epigenetic Drift

Cardiovascular disease (CVD) risk factors can be classed as modifiable or non-modifiable. Physical inactivity and obesity represent major behavioural risk factors for the initiation, development and progression of CVD. Platelet dysfunction is pivotal to the aetiology of CVD, a chronic vascular inflammatory condition, which is characterised by a lag time between onset and clinical manifestation. This indicates the role of epigenetic drift, defined by stochastic patterns of gene expression not dependent on dynamic changes in coding DNA. The epigenome, a collection of chemical marks on DNA and histones, is established during embryogenesis and modified by age and lifestyle. Biogenesis and effector function of non-coding RNA, such as microRNA, play a regulatory role in gene expression and thus the epigenetic mechanism. In this chapter, we will focus on the effect of the modifiable risk factors of physical activity/inactivity and overweight/obesity on platelet function, via epigenetic changes in both megakaryocytopoiesis and thrombopoiesis. We will also discuss the role of acute exercise on platelet function and the impact of cardiorespiratory fitness (CRF) on platelet responses to acute exercise. This chapter will highlight the potential role of platelets as circulating functional biomarkers of epigenetic drift to implement, optimise and monitor CVD preventive management strategies

Platelets: From Formation to Function

Platelets are small, anucleate cells that travel as resting discoid fragments in the circulation. Their average circulating life span is 8–9 days, and their formation is an elegant and finely orchestrated series of cellular processes known as megakaryocytopoiesis and thrombopoiesis. This involves the commitment of haematopoietic stem cells, proliferation, terminal differentiation of megakaryocytic progenitors and maturation of megakaryocytes to produce functional platelets. This complex process occurs in specialised endosteal and vascular niches in the bone marrow where megakaryocytes form proplatelet projections, releasing platelets into the circulation. Upon contact with an injured blood vessel, they prevent blood loss through processes of adhesion, activation and aggregation. Platelets play a central role in cardiovascular disease (CVD), both in the development of atherosclerosis and as the cellular mediator in the development of thrombosis. Platelets have diverse roles not limited to thrombosis/haemostasis, also being involved in many vascular inflammatory conditions. Depending on the physiological context, platelet functions may be protective or contribute to adverse thrombotic and inflammatory outcomes. In this chapter, we will discuss platelets in context of their formation and function. Because of their multifaceted role in maintaining physiological homeostasis, current and development of platelet function testing platforms will be discussed

The context, contribution and consequences of addressing the COVID-19 pandemic : A qualitative exploration of executive nurses' perspectives

Aims To explore (1) the context in which nursing executives were working, (2) nursing's contribution to the healthcare response and (3) the impact from delivering healthcare in response to the pandemic. Design Retrospective, constructivist qualitative study. Methods Individual interviews using a semi-structured interview guide were conducted between 12 February and 29 March 2021. Participants were purposively sampled from the Victorian Metropolitan Executive Directors of Nursing and Midwifery Group, based in Melbourne, Victoria the epi-centre of COVID-19 in Australia during 2020. All members were invited; 14/16 executive-level nurse leaders were participated. Individual interviews were recorded with participant consent, transcribed and analysed using thematic analysis. Results Four inter-related themes (with sub-themes) were identified: (1) rapid, relentless action required (preparation insufficient, extensive information and communication flow, expanded working relationships, constant change, organizational barriers removed); (2) multi-faceted contribution (leadership activities, flexible work approach, knowledge development and dissemination, new models of care, workforce numbers); (3) unintended consequences (negative experiences, mix of emotions, difficult conditions, negative outcomes for executives and workforce) and (4) silver linings (expanded ways of working, new opportunities, strengthened clinical practice, deepened working relationships). Conclusion Responding to the COIVD-19 health crisis required substantial effort, but historical and industrial limits on nursing practice were removed. With minimal information and constantly changing circumstances, nursing executives spearheaded change with leadership skills including a flexible approach, courageous decision-making and taking calculated risks. Opportunities for innovative work practices were taken, with nursing leading policy development and delivery of care models in new and established healthcare settings, supporting patient and staff safety. Impact Nursing comprises the majority of the healthcare workforce, placing executive nurse leaders in a key role for healthcare responses to the COVID-19 pandemic. Nursing's contribution was multi-faceted, and advantages gained for nursing practice must be maintained and leveraged. Recommendations for how nursing can contribute to current and future widespread health emergencies are provided

Interactions between visual and semantic processing during object recognition revealed by modulatory effects of age of acquisition

The age of acquisition (AoA) of objects and their names is a powerful determinant of processing speed in adulthood, with early-acquired objects being recognized and named faster than late-acquired objects. Previous research using fMRI (Ellis et al., 2006. Traces of vocabulary acquisition in the brain: evidence from covert object naming. NeuroImage 33, 958–968) found that AoA modulated the strength of BOLD responses in both occipital and left anterior temporal cortex during object naming. We used magnetoencephalography (MEG) to explore in more detail the nature of the influence of AoA on activity in those two regions. Covert object naming recruited a network within the left hemisphere that is familiar from previous research, including visual, left occipito-temporal, anterior temporal and inferior frontal regions. Region of interest (ROI) analyses found that occipital cortex generated a rapid evoked response (~ 75–200 ms at 0–40 Hz) that peaked at 95 ms but was not modulated by AoA. That response was followed by a complex of later occipital responses that extended from ~ 300 to 850 ms and were stronger to early- than late-acquired items from ~ 325 to 675 ms at 10–20 Hz in the induced rather than the evoked component. Left anterior temporal cortex showed an evoked response that occurred significantly later than the first occipital response (~ 100–400 ms at 0–10 Hz with a peak at 191 ms) and was stronger to early- than late-acquired items from ~ 100 to 300 ms at 2–12 Hz. A later anterior temporal response from ~ 550 to 1050 ms at 5–20 Hz was not modulated by AoA. The results indicate that the initial analysis of object forms in visual cortex is not influenced by AoA. A fastforward sweep of activation from occipital and left anterior temporal cortex then results in stronger activation of semantic representations for early- than late-acquired objects. Top-down re-activation of occipital cortex by semantic representations is then greater for early than late acquired objects resulting in delayed modulation of the visual response

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson