Emma Knight - Academia.edu (original) (raw)

Papers by Emma Knight

Proceedings of the Royal Society B: Biological Sciences, 2011

Animal social behaviour is not static with regard to environmental change. Flexibility in coopera... more Animal social behaviour is not static with regard to environmental change. Flexibility in cooperative resource use may be an important response to resource decline, mediating the impacts of resource availability on fitness and demography. In forest ecosystems, hollow trees are key den resources for many species, but are declining worldwide owing to forestry. Altered patterns of den sharing may mediate the effects of the decline of this resource. We studied den-sharing interactions among hollow-dependent Australian mountain brushtail possums to investigate how spatial variation in hollow tree availability affects resource sharing and kin selection. Under reduced den availability, individuals used fewer dens and shared them less often. This suggests increased territoriality in the presence of resource competition. Further, there was a switch from kin avoidance to kin preference with decreasing hollow tree availability. This was driven primarily by a change in den sharing among sibling...

Genetics, 2005

Marker-based methods for estimating heritability and genetic correlation in the wild have attract... more Marker-based methods for estimating heritability and genetic correlation in the wild have attracted interest because traditional methods may be impractical or introduce bias via G × E effects, mating system variation, and sampling effects. However, they have not been widely used, especially in plants. A regression-based approach, which uses a continuous measure of genetic relatedness, promises to be particularly appropriate for use in plants with mixed-mating systems and overlapping generations. Using this method, we found significant narrow-sense heritability of foliar defense chemicals in a natural population of Eucalyptus melliodora. We also demonstrated a genetic basis for the phenotypic correlation underlying an ecological example of conditioned flavor aversion involving different biosynthetic pathways. Our results revealed that heritability estimates depend on the spatial scale of the analysis in a way that offers insight into the distribution of genetic and environmental vari...

Diversity and Distributions, 2012

AimManagement practices in the landscape matrix can have significant effects on the spatial distr... more AimManagement practices in the landscape matrix can have significant effects on the spatial distribution of animals within adjacent protected areas. This has been well established in agricultural and forested areas, but less is known about how management of the suburban matrix affects adjacent reserves. We argue that it is critically important to understand the impact of suburban management on reserves, as flawed planning decisions can have negative conservation outcomes and waste limited resources.LocationCanberra, Australian Capital Territory, Australia.MethodsWe examined bird distribution patterns in suburbs and adjacent reserves to the effects of two suburban management practices: (1) street tree planting and (2) boundary design. We focused on three groups of birds with known responses to urbanization: native urban‐intolerant species (native avoiders), native urban‐tolerant species (native adapters) and exotic urban‐tolerant species (exotic adapters).ResultsWe found that suburbs...

Biological Conservation, 2010

Large-scale vegetation clearing accompanying agricultural development has been a major driver of ... more Large-scale vegetation clearing accompanying agricultural development has been a major driver of biodiversity loss. Efforts to reverse this problem have often included revegetation, but the value of revegetated areas for biodiversity is poorly known. We addressed aspects of this knowledge gap using a case study in southeastern Australia. We quantified relationships between bird species richness and the probability of detection for eight individual bird species and: (i) the context of a planting, i.e. the types of the vegetation cover in the neighborhood of a planting, (ii) the configuration of a planting, i.e. the location and geometry of a planting, and, (iii) the content of planting, i.e. the vegetation features of a planting. The presence and nature of the effects of these explanatory variables varied with each of our response variables. A combination of context, configuration and content variables were needed to explain the variability in species richness and the presence of individual species. Context effects were highly significant, particularly the amount of planted and remnant native vegetation surrounding plantings. We speculate that when the area surrounding a planting was potentially suitable, recognition of planting ''patch" boundaries disappeared and, correspondingly, configuration effects such as planting size were limited. Our results suggest that maximizing the value of planted areas for bird biota requires consideration not only of the features of the vegetation within a planting, but also where a planting is placed.

Nutrients, 2022

The Australian Feeding Infants and Toddler Study 2021 (OzFITS 2021) is a nationwide survey of Aus... more The Australian Feeding Infants and Toddler Study 2021 (OzFITS 2021) is a nationwide survey of Australian caregivers’ infant and toddler feeding practices. Here, we describe breastfeeding rates and duration, use of breastmilk substitutes, and introduction of complementary (solid) foods, including common food allergens. Caregivers (n = 1140) were recruited by a digital marketing company and were interviewed using a structured telephone questionnaire to obtain information. Breastfeeding was initiated in 98% of infants, but the duration of exclusive breastfeeding to six months was less than 1%. Nearly 40% of children continued to receive breastmilk beyond one year, with 10% of toddlers receiving breastmilk at two years. One-quarter of infants were introduced to solid foods between 4 to 5 months, and nearly all infants had received solid foods by 7 months. New guidelines encourage the early introduction of potential food allergens to reduce the risk of allergy, and by 12 months, over 90%...

JAMA Network Open

IMPORTANCE Maternal milk feeding may have unique long-term neurodevelopmental benefits in very pr... more IMPORTANCE Maternal milk feeding may have unique long-term neurodevelopmental benefits in very preterm infants. OBJECTIVE To examine the extent to which maternal milk feeding after very preterm birth is associated with cognitive, academic, and behavioral outcomes at school age. DESIGN, SETTING, AND PARTICIPANTS This prospective cohort study assessed 586 infants born at less than 33 weeks' gestation at 5 Australian perinatal centers and enrolled in the Docosahexaenoic

Analysis of interactions between longline and recreational gamefish fisheries taking or tagging s... more Analysis of interactions between longline and recreational gamefish fisheries taking or tagging striped marlin off NSW

Frontiers in Pharmacology, 2021

The lungs have evolved complex physical, biological and immunological defences to prevent foreign... more The lungs have evolved complex physical, biological and immunological defences to prevent foreign material from entering the airway epithelial cells. These mechanisms can also affect both viral and non-viral gene transfer agents, and significantly diminish the effectiveness of airway gene-addition therapies. One strategy to overcome the physical barrier properties of the airway is to transiently disturb the integrity of the epithelium prior to delivery of the gene transfer vector. In this study, chemical (lysophosphatidylcholine, LPC) and physical epithelium disruption using wire abrasion were compared for their ability to improve airway-based lentiviral (LV) vector mediated transduction and reporter gene expression in rats. When luciferase expression was assessed at 1-week post LV delivery, LPC airway conditioning significantly enhanced gene expression levels in rat lungs, while a long-term assessment in a separate cohort of rats at 12 months revealed that LPC conditioning did not ...

The Australian Government acting through the Bureau of Rural Sciences has exercised due care and ... more The Australian Government acting through the Bureau of Rural Sciences has exercised due care and skill in the preparation and compilation of the information and data set out in this publication. Notwithstanding, the Bureau of Rural Sciences, its employees and advisers disclaim all liability, including liability for negligence, for any loss, damage, injury, expense or cost incurred by any person as a result of accessing, using or relying upon any of the information or data set out in this publication to the maximum extent permitted by law.

Medical Journal of Australia, 2020

annabis is the most frequently used illicit drug in Australia, probably because of its increasing... more annabis is the most frequently used illicit drug in Australia, probably because of its increasing social and medical acceptance, as well as the recent legalisation of cannabis use in many parts of the world. 1 According to the 2016 National Drug Strategy Household Survey, more than 10% of women of reproductive age had used cannabis during the preceding 12 months. 2 The findings of studies evaluating neonatal outcomes associated with cannabis use by women during pregnancy have been mixed. 3,4 A recent meta-analysis found a significant association between prenatal cannabis exposure and reduced birthweight, as well as increased risk for infants of admission to intensive care. 4 Many studies, however, did not take concurrent cigarette smoking or other illicit substance use into account, and some did not report the time or frequency of cannabis exposure. The largest and most recent study of self-reported cannabis use during pregnancy found increased risks of pre-term birth (adjusted risk ratio [aRR], 1.41, 95% confidence interval [CI], 1.36-1.47), small-for-gestational age (aRR, 1.41, 95% CI, 1.36-1.45), and neonatal intensive care unit admission (aRR, 1.40; 95% CI, 1.36-1.44). 5 Once again, however, the number of cigarettes smoked each day and the time and duration of cannabis use were not assessed. High quality information about the effect of cannabis use during pregnancy on important neonatal outcomes linked to immediate and long term health and wellbeing is needed for informing clinical practice and improving the education of women and health care providers about the potential risks. The aim of our study was therefore to assess associations between duration and frequency of cannabis use during pregnancy on infant birthweight, head circumference, birth length, gestational age, and neonatal morbidity and mortality. Methods Study population The primary aim of the Screening for Pregnancy Endpoints (SCOPE) study, a multicentre prospective cohort study, is to develop screening tests for predicting pre-eclampsia, spontaneous pre-term birth, and small for gestational age babies. 6 A total of 5628 nulliparous women without common risk factors for pregnancy complications were recruited between November 2004 and February 2011 in Adelaide (Australia), Auckland (New Zealand), Cork (Ireland), and Leeds, London and Manchester (United Kingdom). 7 Research midwives collected information on demographic and lifestyle characteristics and medical history from participants at 14-16 weeks of pregnancy. Women were excluded from our analysis if their pregnancy ended earlier than 20 weeks (Supporting Information, figure). Cannabis use by participants The research nurse asked women about the duration and frequency of cannabis use from 3 months before until 15 weeks into their pregnancy. Women were allocated to four categories: never used cannabis, used cannabis but quit before pregnancy, used cannabis but quit during early pregnancy (by 15 weeks), and continued to use cannabis at 15 weeks of pregnancy. Women were also classified according to whether they used cannabis up to once or more than once a week, consistent with previous

The American Journal of Pathology, 2020

Animal models of cystic fibrosis (CF) are essential for investigating disease mechanisms and tria... more Animal models of cystic fibrosis (CF) are essential for investigating disease mechanisms and trialing potential therapeutics. This study generated two CF rat models using clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeatseassociated protein 9 gene editing. One rat model carries the common human Phe508del (DF508) CF transmembrane conductance regulator (CFTR) mutation, whereas the second is a CFTR knockout model. Phenotype was characterized using a range of functional and histologic assessments, including nasal potential difference to measure electrophysiological function in the upper airways, RNAscope in situ hybridization and quantitative PCR to assess CFTR mRNA expression in the lungs, immunohistochemistry to localize CFTR protein in the airways, and histopathologic assessments in a range of tissues. Both rat models revealed a range of CF manifestations, including reduced survival, intestinal obstruction, bioelectric defects in the nasal epithelium, histopathologic changes in the trachea, large intestine, and pancreas, and abnormalities in the development of the male reproductive tract. The CF rat models presented herein will prove useful for longitudinal assessments of pathophysiology and therapeutics.

Magnitude-based inference (MBI) is a controversial statistical method that has been used in hundr... more Magnitude-based inference (MBI) is a controversial statistical method that has been used in hundreds of papers in sports science despite criticism from statisticians. To better understand how this method has been applied in practice, we systematically reviewed 232 papers that used MBI. We extracted data on study design, sample size, and choice of MBI settings and parameters. Median sample size was 10 per group (interquartile range, IQR: 8 – 15) for multi-group studies and 14 (IQR: 10 – 24) for single-group studies; few studies reported a priori sample size calculations (15%). Authors predominantly applied MBI’s default settings and chose “mechanistic/non-clinical” rather than “clinical” MBI even when testing clinical interventions (only 14 studies out of 232 used clinical MBI). Using these data, we can estimate the Type I error rates for the typical MBI study. Authors frequently made dichotomous claims about effects based on the MBI criterion of a “likely” effect and sometimes based...

PLOS ONE, 2015

Cycling is recognised as a sport in which there is a high incidence of poor bone health. Sweat ca... more Cycling is recognised as a sport in which there is a high incidence of poor bone health. Sweat calcium losses may contribute to this. Purpose To examine whether a calcium-rich pre-exercise meal attenuates exercise-induced perturbations of bone calcium homeostasis caused by maintenance of sweat calcium losses. Methods Using a randomized, counterbalanced crossover design, 32 well-trained female cyclists completed two 90 min cycling trials separated by 1 day. Exercise trials were preceded 2 hours by either a calcium-rich (1352 ± 53 mg calcium) dairy based meal (CAL) or a control meal (CON; 46 ± 7 mg calcium). Blood was sampled pre-trial; pre-exercise; and immediately, 40 min, 100 min and 190 min post-exercise. Blood was analysed for ionized calcium and biomarkers of bone resorption (Cross Linked C-Telopeptide of Type I Collagen (CTX-I), Cross Linked C-Telopeptide of Type II Collagen (CTX-II), Parathyroid Hormone (PTH), and bone formation (Procollagen I N-Terminal Propeptide (PINP)) using the established enzyme-linked immunosorbent assay technique. Results PTH and CTX-I increased from pre-exercise to post-exercise in both conditions but was attenuated in CAL (p < 0.001). PTH was 1.55 [1.20, 2.01] times lower in CAL immediately post-exercise and 1.45 [1.12, 1.88] times lower at 40 min post-exercise. CTX-I was 1.40

Journal of sports science & medicine, 2015

The reliability and accuracy of five portable blood lactate (BLa) analysers (Lactate Pro, Lactate... more The reliability and accuracy of five portable blood lactate (BLa) analysers (Lactate Pro, Lactate Pro2, Lactate Scout+, Xpress™, and Edge) and one handheld point-of-care analyser (i-STAT) were compared to a criterion (Radiometer ABL90). Two devices of each brand of analyser were assessed using 22 x 6 mL blood samples taken from five subjects at rest and during exercise who generated lactate ranging ~1-23 mM. Each sample was measured simultaneously ~6 times on each device. Reliability was assessed as the within-sample standard deviation (wsSD) of the six replicates; accuracy as the bias compared with the ABL90; and overall error (the root mean squared error (√MSE)) was calculated as the square root of (wsSD(2) and bias(2)). The √MSE indicated that both the Edge and Xpress had low total error (~0-2 mM) for lactate concentrations <15 mM, whereas the Edge and Lactate Pro2 were the better of the portable analysers for concentrations >15 mM. In all cases, bias (negative) was the maj...

Critical care and resuscitation : journal of the Australasian Academy of Critical Care Medicine, 2006

To determine the safety and efficacy of an intensive insulin regimen compared with a conventional... more To determine the safety and efficacy of an intensive insulin regimen compared with a conventional insulin regimen in general intensive care unit patients. A phase II, randomised controlled trial was conducted in 70 critically ill patients in a closed multidisciplinary ICU of a university-affiliated tertiary hospital. We assessed patient characteristics at baseline. Trial process measures included number of blood glucose measurements per day and number in target range, type and quantity of caloric intake, patient outcome and insulin dosing. The primary outcome was the median blood glucose concentration. Secondary outcome measures were incidence of hypoglycaemia (blood glucose level < 2.2 mmol/L), clinical sequelae of hypoglycaemia and hospital mortality. Thirty-five patients were randomised to each of the two groups. More blood glucose samples were taken per day in the intensive insulin group (16 versus 9), but the number of samples in the normoglycaemic range was 48.5%, compared ...

Medicine & Science in Sports & Exercise, 2015

Purpose: We consider ''magnitude-based inference'' and its interpretation by examining in detail ... more Purpose: We consider ''magnitude-based inference'' and its interpretation by examining in detail its use in the problem of comparing two means. Methods: We extract from the spreadsheets, which are provided to users of the analysis (http:// www.sportsci.org/), a precise description of how ''magnitude-based inference'' is implemented. We compare the implemented version of the method with general descriptions of it and interpret the method in familiar statistical terms. Results and Conclusions: We show that ''magnitude-based inference'' is not a progressive improvement on modern statistics. The additional probabilities introduced are not directly related to the confidence interval but, rather, are interpretable either as P values for two different nonstandard tests (for different null hypotheses) or as approximate Bayesian calculations, which also lead to a type of test. We also discuss sample size calculations associated with ''magnitude-based inference'' and show that the substantial reduction in sample sizes claimed for the method (30% of the sample size obtained from standard frequentist calculations) is not justifiable so the sample size calculations should not be used. Rather than using ''magnitude-based inference,'' a better solution is to be realistic about the limitations of the data and use either confidence intervals or a fully Bayesian analysis.

Journal of Science and Medicine in Sport, 2014

ABSTRACT Introduction: The AlterG treadmill was designed in 2009 with the assistance of NASA in o... more ABSTRACT Introduction: The AlterG treadmill was designed in 2009 with the assistance of NASA in order to mimic the effects of anti-gravity running. Currently, literature asserts that the relationship between speed, body weight and load on the treadmill is linear. However, this body of work is with a small sample size and does not include running. As a result, current rehabilitation prescription is not evidence based. Clinical use of the AlterG suggests that there is a non-linear relationship between body weight, speed and load in running. The purpose of this study was aimed to determine the relationship between these three variables, thus allowing clinicians to use an algorithm by which they can prescribe rehabilitation sessions on the AlterG treadmill. Methods: Elite (n=6) and sub-elite (n=4) athletes gave written informed consent. Ethical approval was granted by Australian Institute of Sport Ethics Committee. The testing protocol consisted of 45 second running intervals ranging from 10km/h to 20km/h with 2km/h increments. This protocol was competed at 100% - 50% of bodyweight (BW) as indicated on the AlterG. The ViPerform (DorsaVi Ltd, Australia) was used to measure athletes lower limb loads (arbitrary units) for the varying speed and levels of body weight. These values were normalised to percentage of load at 100% BW for analysis. Multiple trials were recorded at 10%BW intervals (between 50-100%) for each speed. To determine the independent relationships between height, weight, age and gender with load, a mixed-effect restricted maximum likelihood (REML) univariate regression was utilised with height, weight, age or gender as a fixed effect and random effects for participant. The relationship of the load with speed and bodyweight percentage was analysed by mixed-effect REML multivariate regression with fixed effects of speed, bodyweight setting and random effects for participant. Results: Univariate analyses showed body weight increment to have a significant effect on load (p=0.00) whereas speed (p=0.75), height (p=0.23), age (p=0.27), gender (p=0.15) and weight (p=0.09) were not found to have non-significant effect on load. Multivariate analyses showed significant effects between each body weight (p=0.00) and speed (p=0.00) increments on load. The multivariate equation was Relative load (%) = -51.90+1.50*(%BW)+0.14*Speed. Discussion: Our results indicate that body weight has a greater effect on load that speed on the AlterG treadmill. This suggests that, within a rehabilitation session, speed should be the first progression and then increasing body weight when clinicians are concerned with the amount of impact.