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Managing glycaemic control in individuals with type 2 diabetes mellitus: Assessing the influence of exercise timing
Get PDFExercise is a cornerstone of type 2 diabetes (T2D) management and is of paramount importance. Past research has investigated various elements of exercise (frequency, intensity, time, etc.) for optimal glycaemic control in those with T2D. However, the physical activity (PA) levels of those with T2D are still not improving (i.e., time constraints, fear of exercise, etc.). The diurnal timing of exercise is a recent topic of interest, and may be an important exercise variable to manipulate in the hope of improving the management of T2D.
Within this thesis, a systematic review (Chapter 2) was undertaken to understand the effect of exercise timing on both acute and chronic glycaemic control measures in individuals with T2D. The aim of the systematic review was to review the literature associated with diurnal exercise timing and glycaemic control in individuals with T2D. Systematic searches of online data bases for randomized controlled trials published in English were performed from inception to September 2021. The screening of both the title and abstract, and the full-text of all attained sources were carried out by three authors and resolved by a fourth member of the team. Thereafter, three authors independently utilized the Cochrane Collaboration Risk of Bias Assessment Tool Version 2 (RoB2) and The Cochrane Collaboration Data Collection Form for the completion of study quality and data extraction of articles, respectively. A qualitative synthesis was performed on the included studies, with results summarized in tables. Twenty-seven studies (752 participants: 23 crossover and 4 parallel-groups) were included in the final qualitative synthesis. Greater improvements in average glucose concentrations were observed when exercise was performed in the morning compared to evening exercise; however, similar improvements in glucose area under the curve (AUC) were seen for both morning and evening exercise. Based on large study design heterogeneity, the observations were largely based on indirect comparisons given the limited number of studies that directly investigated the timing of exercise. Therefore, although current evidence indicates that there may be an important relationship between diurnal exercise timing and glycaemic control in individuals with T2D, it remains inconclusive whether this link is a viable mean for glycaemic control management; however, future low risk trials are warranted to help distinguish a possible relationship.
The systematic review indicated that the effect of diurnal exercise timing on glycaemic control remains inconclusive, and as such, a Randomised Controlled Trial (RCT) was conducted to investigate the effects of morning vs evening exercise. The study (Chapter 3) pursued to determine the impact of diurnal exercise timing on i) fasting glycaemic control and insulin resistance measures; ii) postprandial glycaemic control and; iii) measures of body anthropometrics/composition and physical activity measures in overweight individuals with T2D enrolled into a 12-week supervised multi-modal exercise training program (3 days per week; each session 4 resistance-based exercises for 3 sets of 8-12 repetitions and 30 minutes walking). Secondarily, the study sought to explore potential mechanisms associated with improved glycaemic control following exercise training in those with T2D; more specifically, through intracellular glucose metabolism pathways. The conducted intervention improved measures of glycaemic control, body composition, body anthropometrics, cardiorespiratory fitness and maximal strength in individuals with T2D; however, this was irrespective of diurnal exercise timing. Although sRAGE, methylglyoxal and L-lactate did not demonstrate a change in their systemic concentrations, further work adopting intracellular measures of these markers will be required to discard their mechanistic involvement. The existing evidence and recommendations support the manipulation of exercise intensity, type and volume (duration and frequency) to help manage glycaemia in individuals with T2D; however, findings from this study suggest that diurnal timing may not be a considerable factor in a holistic management program.
In conclusion, the findings presented in this thesis provide evidence of tactically manipulating the diurnal timing of exercise on glycaemic control in overweight individuals with T2D. Despite this manipulation of diurnal exercise timing not resulting in any additional benefits of glycaemic control, this thesis provides reason that the current exercise guidelines are an effective tool for i) improving glycaemic control; ii) improving cardiovascular health and physical activity and; iii) improving body anthropometric and body compositive measures in individuals with T2D. Results suggesting that the frequency of exercise performance could be a vital component for the management of T2D
The Staphylococcus aureus Network Adaptive Platform Trial Protocol: New Tools for an Old Foe
No full textStaphylococcus aureus bloodstream (SAB) infection is a common and severe infectious disease, with a 90-day mortality of 15%–30%. Despite this, <3000 people have been randomized into clinical trials of treatments for SAB infection. The limited evidence base partly results from clinical trials for SAB infections being difficult to complete at scale using traditional clinical trial methods. Here we provide the rationale and framework for an adaptive platform trial applied to SAB infections. We detail the design features of the Staphylococcus aureus Network Adaptive Platform (SNAP) trial that will enable multiple questions to be answered as efficiently as possible. The SNAP trial commenced enrolling patients across multiple countries in 2022 with an estimated target sample size of 7000 participants. This approach may serve as an exemplar to increase efficiency of clinical trials for other infectious disease syndromes
Molecular and histopathological characterisation of peripheral nerve and immune cell distributions in normal and virus infected mouse tissues
Get PDFBoth nervous and immune systems can exist as two separated systems in terms of function. However, they are considered the main sensory interfaces that have developed to sense the internal and external environmental stimuli to maintain the host homeostasis and survival in healthy and disease states either. Various branches of the peripheral nervous system (PNS), including the sympathetic and parasympathetic together with the sensory nervous system and the enteric nervous system, interact with the immune system to sustain homeostasis and regulate the immune response of secondary lymphoid tissues and organs (SLTO). The neuro-immune molecular communications are mediated by soluble molecules which have pro-inflammatory or anti-inflammatory impacts, namely, cytokines and chemokines released by the immune system, as well as neurotrophins and neuropeptides released by the PNS. Therefore, the study of neuroimmune interactions is crucial to get more knowledge and to understand the cross-regulation between these vital systems within secondary lymphoid tissues and organs (SLTO), and from another aspect is to investigate the influences of respiratory viral infections on the bidirectional cross-talk. Started with, the specificity of mouse anti-neurofilament heavy (NF-H) ( neuronal antibody) and anti-immune cell antibodies which have been applied in this study through the use of immunofluorescent staining (IF) combined with confocal microscopy to demonstrate such innervation of Peyer's patches, thymus, and spleen, further, a type of the reciprocal relationship of these nerve cells with immune cells within these tissues in normal condition was characterized.
As it is Known, the influenza A virus (IAV) is one of the major pathogens of human and animal respiratory tract infections with epidemics causing significant morbidity and mortality worldwide. To evaluate neuro-immune interactions during the viral infection, the murine model was used and only female mice were utilized in this study since that females are more susceptible than males to being infected by IAVs. Moreover, females can produce neutralizing antibodies, cytokines, and chemokines at higher levels than males during IAV infections (Geurs et al., 2012). Further, influenza A/PR/8/34 H1N1 virus (PR8), is a mouse-adapted influenza strain that provokes the destruction of alveolar type II (ATII) cells in mouse alveoli making it a suitable model. Such experiments showed that the molecular mechanism of the reciprocal neuro-immune relationship was influenced by the infection through the emergence of the immune response against the virus, which was characterized by the presence of immune cells and antigen-presenting cells (APCs) in abundance in situ compared with the control tissues.
This project additionally investigated the metabolic signature and gene-expressed changes that occur in the murine host response to lung inflammation generated by influenza A virus infection. Importantly, metabolites are found inside organisms as either amino acids or tryptophan. Amino acids act as a progenitor to various biomolecules and have a major effect on immune and neuronal functions. Induction of changes in plasma amino acid levels is associated with diseases (Kelly & Pearce, 2021). Tryptophan on the other hand is involved in biological pathways such as the control of inflammation, regulation of energy homeostasis, and synthesis of neurotransmitters. A metabolomic study of blood plasma metabolites has been conducted throughout the experimental infection. The best results obtained were at the acute stage (7 dpi) of the infection revealed a significant difference of six amino acids and one tryptophan pathway metabolites between control and infected samples amongst other time points of the disease. Three metabolites were elevated in plasma at peak infection (taurine, 5-Oxoproline, glutamine) and 4 were lower in infection (serine, glycine, citrulline, indole-3-acetic acid). This is indicative of a neuroprotective, antioxidant, and immunostimulatory phenotype.
To identify gene expression patterns in lung, thymus, spleen, and Peyer’s patches, glial fibrillary acidic protein (GFAP), brain-derived neuropeptide factor (BDNF), and haemagglutinin antigen (HA) of IAV genes were chosen. Analytic data revealed that these genes of interest were expressed by lung cells obviously and showed significant changes between infected and control animals in a comparison with other tissues. On the other hand, at a peak of infection, and when we utilized more neural genes on the same tissues as well as the brain, we noticed that there was a significant difference in both the lung and brain.
To investigate differentially expressed genes, RNA-seq analysis was performed utilizing the data of the recovery stage (21 dpi) of infection comparing control and infected samples, which may have been new insights into the molecular pathogenesis of IAV infection and its impact on the reciprocal neuro-immune interaction. The bioinformatic analysis detected upregulation of a majority of Immunoglobulin genes, immune infiltration, nerve cells, and genes encoding components of various signaling pathways.
In conclusion, more characterization and greater understanding of the neuroimmune interaction by which the PNS might affect the SLTO and its responses, and vice versa in health and disease is further required. Consequently, this can control the pathogenesis of many neuro/immunological as well as infectious diseases by the development of novel and beneficial therapies for the treatment of these diseases
A qualitative exploration of the motor skills required for elite triathlon performance
No full textPurpose
The purpose of this research was to investigate the beliefs, attitudes, and experiences of stakeholders in youth triathlon regarding the important motor subskills that are required to be successful at the elite level of triathlon competition.
Method
Twenty-five participants were recruited from five stakeholder groups in triathlon and interviewed via video conference. A constructionist and relativist approach to thematic analysis was used to identify three first order themes and several second order themes.
Results
The first, first order theme was ‘Continuous Motor Skills' which consisted of the invariant features of triathlon's continuous motor skills and the parameterization of continuous motor skills. The second, first order theme was ‘Discrete Motor Skills' and consisted of discrete motor skills involved with cornering and change of direction in each discipline and transition phases in triathlon. The final first order theme was ‘Adaptability in Continuous and Discrete Motor Skills'.
Conclusion
This research provides a novel and more broad understanding of the beliefs, attitudes, and experiences of stakeholders in triathlon regarding important motor skills that are required to succeed at the elite level of the sport. This novel and broad understanding of important triathlon motor skills has theoretical implications for evaluating triathlon performance with skill acquisition as a primary focus. Additionally, this research is practically important for coaches, administrators, and athletic performance staff who design training programs and pathways for young, developing triathletes
Blood pressure interactions with the DASH dietary pattern, sodium, and potassium: The International Study of Macro-/Micronutrients and Blood Pressure (INTERMAP)
Get PDFBackground
Adherence to the Dietary Approaches to Stop Hypertension (DASH) diet enhances potassium intake and reduces sodium intake and blood pressure (BP), but the underlying metabolic pathways are unclear.
Objectives
Among free-living populations, we delineated metabolic signatures associated with the DASH diet adherence, 24-hour urinary sodium and potassium excretions, and the potential metabolic pathways involved.
Methods
We used 24-hour urinary metabolic profiling by proton nuclear magnetic resonance spectroscopy to characterize the metabolic signatures associated with the DASH dietary pattern score (DASH score) and 24-hour excretion of sodium and potassium among participants in the United States (n = 2164) and United Kingdom (n = 496) enrolled in the International Study of Macro- and Micronutrients and Blood Pressure (INTERMAP). Multiple linear regression and cross-tabulation analyses were used to investigate the DASH-BP relation and its modulation by sodium and potassium. Potential pathways associated with DASH adherence, sodium and potassium excretion, and BP were identified using mediation analyses and metabolic reaction networks.
Results
Adherence to the DASH diet was associated with urinary potassium excretion (correlation coefficient, r = 0.42; P < 0.0001). In multivariable regression analyses, a 5-point higher DASH score (range, 7 to 35) was associated with a lower systolic BP by 1.35 mmHg (95% CI, −1.95 to −0.80 mmHg; P = 1.2 × 10−5); control of the model for potassium but not sodium attenuated the DASH-BP relation. Two common metabolites (hippurate and citrate) mediated the potassium-BP and DASH-BP relationships, while 5 metabolites (succinate, alanine, S-methyl cysteine sulfoxide, 4-hydroxyhippurate, and phenylacetylglutamine) were found to be specific to the DASH-BP relation.
Conclusions
Greater adherence to the DASH diet is associated with lower BP and higher potassium intake across levels of sodium intake. The DASH diet recommends greater intake of fruits, vegetables, and other potassium-rich foods that may replace sodium-rich processed foods and thereby influence BP through overlapping metabolic pathways. Possible DASH-specific pathways are speculated but confirmation requires further study. INTERMAP is registered as NCT00005271 at www.clinicaltrials.gov
Climate change and altered fire regimes: Impacts on plant populations, species, and ecosystems in both hemispheres
No full textExtreme fire seasons in both hemispheres in 2019 and 2020 have highlighted the strong link between climate warming and altered fire regimes. While shifts in fire regimes alone can drive profound changes in plant populations, communities, and ecosystems, the direct effects of warming climate conditions can impose added stress on key demographic processes prior to and immediately following fire. Altered survival-, growth-, and reproductive- rates in periods between fires, coupled with post-fire recruitment failure from increasingly stressful environmental conditions (including both heatwave and drought) can pose serious threats for conservation in fire-adapted ecosystems worldwide, raising concerns of ecosystem conversion and state change. In this special issue, a collection of 11 papers from fire-prone ecosystems in both hemispheres documents key insights into how changes are unfolding—and mechanisms underpinning such changes—across a diverse range of species and ecosystems. Here, we synthesize this work that uses latitudinal observational surveys, experiments, and simulation modeling to understand how climate warming and altered fire regimes are reshaping our planet. We place these studies in the context of broader advances, and highlight additional research directions to uncover how altered fire regimes, fires interacting with other disturbances, and pre-and post-fire demographic processes can erode resilience in a warming climate
A review of ecological impacts from recreational SCUBA diving: Current evidence and future practice
No full textGlobal demand for SCUBA diving activities in coastal areas continues to grow. Academic research has acknowledged that SCUBA diving can have ecological impacts. To understand the current state of knowledge this study applied the systematic quantitative literature review method (SQLR) to determine what evidence is available on ecological impacts from recreational SCUBA diving. In total 69 research articles about ecological impacts of SCUBA diving were analysed. This paper explored research trends, geographical distribution of research articles, nature of impact and management recommendations for future practice. The research found that SCUBA diving impacted through diver contact with coral reefs caused breakage, fragmentation and led to disease. 10 coral varieties were identified as impacted including some listed as (critically) endangered or vulnerable by the IUCN. Impacts can be minimized using non-regulatory and regulatory management strategies. We present a novel framework that connects diver characteristics with coral reef impacts and discuss how to apply this framework and guide future studies in this area of SCUBA diving research
Who are the chiropractic students favouring a limitless scope of practice? Exploring the relationship with personality, magical thinking, and academic achievement
Get PDFIntroduction
Some chiropractors seem to have an inflated belief in the powers of spinal manipulation (SMT), for example aiming at preventing future spinal degeneration and health problems, activities that are without supporting evidence. Non-evidenced health beliefs have been shown to be associated with a tendency toward magical thinking. Holding such beliefs about SMT is associated with a limitless scope of practice (LLSoP). Recent studies have shown that “chiropractic conservatism” (ChiroCon) is also associated with such approaches. We wanted to understand ChiroCon and these attitudes toward SMT by exploring three different factors: intolerance to uncertainty, academic achievement, and tendency toward magical thinking and how they relate to ChiroCon and LLSoP.
Method
A cross-sectional survey of 243 chiropractic students from an Australian chiropractic program was conducted in May 2020. Students answered a questionnaire involving a patient case-scenario for LLSoP, levels of ChiroCon, validated questionnaires on (i) Intolerance of uncertainty, (ii) Academic achievement, and (iii) Magical thinking. LLSoP was defined as wanting to treat with SMT a 5-year-old asymptomatic child for future (i) Musculoskeletal (MSK) problems and/or (ii) Non-musculoskeletal diseases. Logistic regression models were used to confirm if there was an association between ChiroCon and LLSoP and to explore associations between LLSoP and (i) Intolerance of uncertainty, (ii) Academic achievement, and (iii) Magical thinking. We repeated the same analyses using ChiroCon as the outcome variable.
Results
We confirmed that chiropractic students in the more extreme ChiroCon group were more likely to want to prevent future spinal disorders in an asymptomatic 5-year-old child as compared to those with lower levels (OR = 3.9, (95%CI 1.97–7.72). This was also the case for the prevention of future diseases in the same child (OR = 6.9, (95%CI 3.11–15.06). Of the three predictor variables, magical belief was positively associated with both ChiroCon and LLSoP.
Conclusion
Not surprisingly, ChiroCon is closely related to LLSoP and both were linked to magical thinking. Therefore, the questionnaire ‘Magical Health Beliefs’ could be a useful instrument to screen future chiropractic students to prevent a mismatch between student and institution. Depending on the outlook of the school, some schools would welcome these students, whereas other institutions would want to avoid them in their education program
The long and the short of it: Mechanisms of synchronous and compensatory dynamics across temporal scales
Get PDFSynchronous dynamics (fluctuations that occur in unison) are universal phenomena with widespread implications for ecological stability. Synchronous dynamics can amplify the destabilizing effect of environmental variability on ecosystem functions such as productivity, whereas the inverse, compensatory dynamics, can stabilize function. Here we combine simulation and empirical analyses to elucidate mechanisms that underlie patterns of synchronous versus compensatory dynamics. In both simulated and empirical communities, we show that synchronous and compensatory dynamics are not mutually exclusive but instead can vary by timescale. Our simulations identify multiple mechanisms that can generate timescale-specific patterns, including different environmental drivers, diverse life histories, dispersal, and non-stationary dynamics. We find that traditional metrics for quantifying synchronous dynamics are often biased toward long-term drivers and may miss the importance of short-term drivers. Our findings indicate key mechanisms to consider when assessing synchronous versus compensatory dynamics and our approach provides a pathway for disentangling these dynamics in natural systems
The effect of necrophagous entomofauna on textile damage during the summer in Western Australia
No full textLearning Overview: After attending this presentation, attendees will have a better understanding of the impact and the artifacts produced by the activity of necrophagous entomofauna on stab-cuts and tear damage on different types of fabric during the postmortem period.
Impact Statement: This presentation will impact the forensic science community by increasing awareness of the effect of carrion insects on clothing and by providing a new body of information that will enhance the investigative role of clothing associated with decomposed and skeletonized remains.
Fatal stabbing incidents are the leading cause of homicides in countries with restricted access to firearms, such as Australia.1 During a stabbing assault, the distinctive characteristics of a sharp implement will deposit specific features.2 When the decomposition process impedes the physical examination of a stab wound, damage analysis of the clothing may provide information about the weapon or the actions that caused the injury.3 Studies have suggested that insect activity associated with decomposition can produce artifacts on textiles, modify perimortem textile damage or produce changes to clothing that imitate indicators of sexual homicides.4-7 However, the extent of such studies is currently limited and have not been conducted in Australia before. The aim of this research was to identify and characterize the effect of carrion insects on textile damage after a decomposition period during summer in Australia.
The effect of insect activity was analyzed on standardized cuts and tears to three different fabrics (100% cotton, 65% polyester-35% cotton, 80% nylon- 20% spandex). Ninety stillborn piglets (Sus scrofa domesticus L.) were wrapped in one type of fabric each. Each clothed piglet was either stabbed by a stabbing apparatus or had its fabric torn. All piglets were placed simultaneously in a decomposition facility alongside controls of each combination of fabric and damage type, including 9 piglets clothed and intact; 6 piglets unclothed and stabbed or intact; 11 piglets enclosed in boxes; 36 field swatches; and 9 laboratory swatches. Over five sampling periods and until complete skeletonization (7, 12, 18, 26, 47 days since placement), 3 piglets of each type were removed, and entomological samples were collected. The fabric of each piglet was removed, photographed, and stored to dry in laboratory conditions before being analyzed. All controls and fabric swatches were collected on the final sampling day.
Data collection was comprehensive of piglet and fabric samples via field assessment, daily photo and video documentation, static camera recording, and direct collection of insect specimens. Analyses performed covered taphonomic aspects (degree of piglet decomposition), entomological (insect species and instar), and textile damage analysis. The collected fabrics were analyzed on different levels of fabric structure using a stereoscope and digital microscope and through photo and video analysis. Fibers of each sample type were collected and examined using optical microscopy and Scanning Electron Microscopy (SEM).
The results of this research show that stab cuts can adopt morphological characteristics over time that may resemble features of tear damage, whereas tear characteristics also tend to fade gradually. Insect interaction with bloodstains resulted in a distortion of the yarns and of the fabric surface after fly feeding. Due to the weakening of the fabric’s structure, insect damage and consequent degradation may occur at the same location. The assessment and comparison of fabrics revealed how parameters such as the type of fabric and elasticity can influence insect damage, with natural fabrics being the most vulnerable. Lastly, this research emphasizes how the presence and the type of fabrics and textile damage affect the interaction of carrion insects with the decomposing medium, and consequently, how the rate of decomposition in a natural environment and in confined spaces is affected