Constructing Wildebeest Density Distributions by Spatio-temporal Smoothing of Ordinal Categorical Data Using GAMs

Spatio-temporal smoothing of large ecological datasets describing species distributions can be made challenging by high computational costs and deficiencies in the available data. We present an application of a GAM-based smoothing method to a large ordinal categorical dataset on the distribution of wildebeest in the Serengeti ecosystem

Inference of the drivers of collective movement in two cell types: Dictyostelium and melanoma

Collective cell movement is a key component of many important biological processes, including wound healing, the immune response and the spread of cancers. To understand and influence these movements, we need to be able to identify and quantify the contribution of their different underlying mechanisms. Here, we define a set of six candidate models—formulated as advection–diffusion–reaction partial differential equations—that incorporate a range of cell movement drivers. We fitted these models to movement assay data from two different cell types: Dictyostelium discoideum and human melanoma. Model comparison using widely applicable information criterion suggested that movement in both of our study systems was driven primarily by a self-generated gradient in the concentration of a depletable chemical in the cells' environment. For melanoma, there was also evidence that overcrowding influenced movement. These applications of model inference to determine the most likely drivers of cell movement indicate that such statistical techniques have potential to support targeted experimental work in increasing our understanding of collective cell movement in a range of systems

'A Sentence of Last Resort': the order for lifelong restriction and the sentencing of dangerous offenders in Scotland

This thesis is a critical analysis of the order for lifelong restriction (OLR). The OLR is a risk-based indeterminate sentence of imprisonment. It is imposed when the offender satisfies certain statutory risk criteria for the protection of the public. This thesis has four main aims: (1) to identify an appropriate theoretical basis for the imposition of preventive detention that is capable of supporting an ethically defensible model of preventive sentencing, and of serving as an analytical model for application to the OLR; (2) to give a detailed and critical account of the OLR’s operational framework; (3) to assess the extent to which the current statutory framework conforms to the requirements identified in the analytical model proposed in relation to the first aim; and (4) in light of this to propose amendments to the relevant legislation. The thesis concludes that preventive sentencing is best conceptualised as a punitive form of societal self-defence, the right of which is engaged when an offender exercises his autonomy such as to violate the rights of others in a way that threatens lasting physical or psychological harm. Since the need to consider preventive detention has arisen from fault on the offender’s part, it is morally permissible to require him to bear the burden of any uncertainty as to repeat offending. The derogation from the principle of desert-proportionality requires to be tempered with threat-proportionality. This means that the offences to which preventive sentences may apply must be restricted to serious offences against the person, or other offences which threaten physical harm to persons – this has the effect of excluding property offences that do not endanger others. Finally, it is concluded that, while the OLR is, in general terms, an ethically defensible model of preventive detention, some modifications to the procedural framework ought to be considered in order to restrict its scope

Modelling collective movement across scales: from cells to wildebeest

Collective movements are ubiquitous in biological systems, occurring at all scales; from the sub-organismal movements of groups of cells, to the far-ranging movements of bird flocks and herds of large herbivores. Movement patterns at these vastly different scales often exhibit surprisingly similar patterns, suggesting that mathematically similar mechanisms may drive collective movements across many systems. The aims of this study were three-fold. First, to develop mechanistic movement models capable of producing the observed wealth of spatial patterns. Second, to tailor statistical inference approaches to these models that are capable of identifying drivers of collective movement that could be applied to a wide range of study systems. Third, to validate the approaches by fitting the mechanistic models to data from diverse biological systems. These study systems included two small-scale in vitro cellular systems, involving movement of groups of human melanoma cells and Dictyostelium discoideum (slime mould) cells, and a third much larger-scale system, involving wildebeest in the Serengeti ecosystem. I developed a series of mechanistic movement models, based on advection-diffusion partial differential equations and integro-differential equations, that describe changes in the spatio-temporal distribution of the study population as a consequence of various movement drivers, including environmental gradients, environmental depletion, social behaviour, and spatial and temporal heterogeneity in the response of the individuals to these drivers. I also developed a number of approaches to statistical inference (comprising both parameter estimation and model comparison) for these models that ranged from frequentist, to pseudo-Bayesian, to fully Bayesian. These inference approaches also varied in whether they required numerical solutions of the models, or whether the need for numerical solutions was bypassed by using gradient matching methods. The inference methods were specifically designed to be effective in the face of the many difficulties presented by advection-diffusion models, particularly high computational costs and instabilities in numerical model solutions, which have previously prevented these models from being fitted to data. It was also necessary for these inference methods to be able to cope with data of different qualities; the cellular data provided accurate information on the locations of all individuals through time, while the wildebeest data consisted of coarse ordinal abundance categories on a spatial grid at monthly intervals. By applying the developed models and inference methods to data from each study system, I drew a number of conclusions about the mechanisms driving movement in these systems. In all three systems, for example, there was evidence of a saturating response to an environmental gradient in a resource or chemical attractant that the individuals could deplete locally. I also found evidence of temporal dependence in the movement parameters for all systems. This indicates that the simplifying assumption that behaviour is constant, which has been made by many previous studies that have modelled movement, is unlikely to be justified. Differences between the systems were also demonstrated, such as overcrowding affecting the movements of melanoma and wildebeest, but not Dictyostelium, and wildebeest having a much greater range of perception than cells, and thus being able to respond to environmental conditions tens of kilometres away. The toolbox of methods developed in this thesis could be applied to increase understanding of the mechanisms underlying collective movement in a wide range of systems. In their current form, these methods are capable of producing very close matches between models and data for our simple cell systems, and also produce a relatively good model fit in the more complex wildebeest system, where there is, however, still some room for improvement. While more work is required to make the models generalisable to all taxa, particularly through the addition of memory-driven movement, inter-individual differences in behaviour, and more complex social dynamics, the advection-diffusion modelling framework is flexible enough for these additional behaviours to be incorporated in the future. A greater understanding of what drives collective movements in different systems could allow management of these movements to prevent the collapse of important migrations, control pest species, or prevent the spread of cancer

How Stressed are Students and What Can We Do About It? Findings from a Self-report Survey of Contract Cheating Behaviours and the Stressful Events College Students Experience

Empirical research on contract cheating in Canada has been limited (Eaton, 2022) and tends to focus on the university (Eaton, 2019; Stoesz & Los, 2019; Thacker, 2022) while there has been relatively little research on academic integrity and contract cheating in community colleges and other non-university higher education institutions (Bretag & Harper, 2020). To address this gap, in 2021, researchers collected data on student engagement in academic integrity violation behaviour and the stress they experienced as they were completing their programs at one Canadian community college. Using self-report survey methodology and utilizing students as partners in research, we found students engaged in a variety of contract cheating behaviours, and experienced a myriad of stressful events both in and outside the college context, including traumatic life events. In this presentation, we explore the link between stress and contract cheating behaviour and address how we can respond at all levels of our institutions to better support students and promote academic integrity.    &nbsp

Adaptation of New Colombian Food-based Complementary Feeding Recommendations Using Linear Programming.

OBJECTIVE: The aim of the study was to use linear programming (LP) analyses to adapt New Complementary Feeding Guidelines (NCFg) designed for infants aged 6 to 12 months living in poor socioeconomic circumstances in Bogota to ensure dietary adequacy for young children aged 12 to 23 months. DESIGN: A secondary data analysis was performed using dietary and anthropometric data collected from 12-month-old infants (n = 72) participating in a randomized controlled trial. LP analyses were performed to identify nutrients whose requirements were difficult to achieve using local foods as consumed; and to test and compare the NCFg and alternative food-based recommendations (FBRs) on the basis of dietary adequacy, for 11 micronutrients, at the population level. RESULTS: Thiamine recommended nutrient intakes for these young children could not be achieved given local foods as consumed. NCFg focusing only on meat, fruits, vegetables, and breast milk ensured dietary adequacy at the population level for only 4 micronutrients, increasing to 8 of 11 modelled micronutrients when the FBRs promoted legumes, dairy, vitamin A-rich vegetables, and chicken giblets. None of the FBRs tested ensured population-level dietary adequacy for thiamine, niacin, and iron unless a fortified infant food was recommended. CONCLUSIONS: The present study demonstrated the value of using LP to adapt NCFg for a different age group than the one for which they were designed. Our analyses suggest that to ensure dietary adequacy for 12- to 23-month olds these adaptations should include legumes, dairy products, vitamin A-rich vegetables, organ meat, and a fortified food

Context-specific complementary feeding recommendations developed using Optifood could improve the diets of breast-fed infants and young children from diverse livelihood groups in northern Kenya.

OBJECTIVE: To formulate age- and context-specific complementary feeding recommendations (CFR) for infants and young children (IYC) and to compare the potential of filling population-level nutrient gaps using common sets of CFR across age groups. DESIGN: Linear programming was used to develop CFR using locally available and acceptable foods based on livelihood- and age-group-specific dietary patterns observed through 24 h dietary recalls. Within each livelihood group, the nutrient potential of age-group-specific v. consolidated CFR across the three age groups was tested. SETTING: Three food-insecure counties in northern Kenya; namely, settled communities from Isiolo (n 300), pastoralist communities from Marsabit (n 283) and agro-pastoralist communities from Turkana (n 299). SUBJECTS: Breast-fed IYC aged 6-23 months (n 882). RESULTS: Age-specific CFR could achieve adequacy for seven to nine of eleven modelled micronutrients, except among 12-23-month-old children in agro-pastoralist communities. Contribution of Fe, Zn and niacin remained low for most groups, and thiamin, vitamin B6 and folate for some groups. Age-group-consolidated CFR could not reach the same level of nutrient adequacy as age-specific sets among the settled and pastoralist communities. CONCLUSIONS: Context- and age-specific CFR could ensure adequate levels of more modelled nutrients among settled and pastoralist IYC than among agro-pastoralist communities where use of nutrient-dense foods was limited. Adequacy of all eleven modelled micronutrients was not achievable and additional approaches to ensure adequate diets are required. Consolidated messages should be easier to implement as part of a behaviour change strategy; however, they would likely not achieve the same improvements in population-level dietary adequacy as age-specific CFR

How to Strengthen the CMAM programme in Northern Nigeria and reduce rates of programme defaulting

This report presents findings from the operations research (OR) study which was conducted to identify barriers to attendance of the Maternal Neonatal and Child Health Weeks programme (MNCHW), in two states of northern Nigeria – Jigawa and Zamfara States. The work was a collaborative project between the London School of Hygiene & Tropical Medicine, Food Basket Foundation International and Oxford Policy Management. The treatment and prevention of severe acute malnutrition via the Community Management of Acute Malnutrition programme (CMAM) is one of four outputs of the DFID-funded development project “Working to Improve Nutrition in Northern Nigeria” (WINNN). This output aims to deliver, in the five WINNN supported northern states, effective treatment for severe acute malnutrition through local health systems. WINNN is implemented by UNICEF, Action Against Hunger (ACF) and Save the Children International (SCI), in partnership with the five state governments. SCI is responsible for its implementation in Zamfara, Kebbi and Katsina states, and ACF is responsible for its implementation in Jigawa and Yobe states. The CMAM services include: (1) Community outreach, for the early identification and referral of severe acute malnutrition (SAM) and later follow-up; (2) Outpatient care for children with SAM without medical complications at health facilities and at home (Outpatient Therapeutic Programme, OTP); (3) Inpatient care for children with SAM, and medical complications or no appetite (Inpatient Therapeutic Programme, ITP)

Rates of common communicable illnesses in non-anaemic 12-24 month old South Island, New Zealand children

Aims : To describe the incidence of parentally reported illness in otherwise healthy South Island toddlers; characterise the predictors of illness; and determine whether there was a relationship between teething and illness in this population.Methods : A 20-week randomised controlled trial was conducted on 1-year-old children (n=225) from Otago and Southland between February 2004 and December 2005. Information on symptoms of morbidity, occurrence of teething, and childcare attendance were recorded daily throughout the intervention period. Morbidity symptoms were categorised into respiratory illness (RI), gastrointestinal illness (GII), ear infection, and total illness, and the number and duration of events were determined.Results : The mean (SD) number of total illnesses was 3.4 (2.3) per 20 weeks, with an average duration of 4.5 days. Episodes of RI were most common (50% of total illness events), and tended to be the longest in duration (mean of 3.7 days). Having siblings aged less than 5 years (23% increase, 95%CI 6%&ndash;42%, p=0.007) and attending childcare (72% increase, 95%CI 38%&ndash;113%, p&lt;0.001)), were positively associated with the number of total illness events but not duration. In addition, teething was positively associated with total events (OR 1.94, 95%CI 1.45&ndash;2.60, p&lt;0.001), RI events (OR 2.03, 95%CI 1.41&ndash;2.93, p&lt;0.001) and GII events (OR 1.90, 95%CI 1.36&ndash;2.67, p&lt;0.001). Conclusion : This study has shown that illness (particularly RI) is common in the second year of life. It has also confirmed that attending childcare and having siblings aged under 5 years increases the number of illness events. An association between teething and the occurrence of illness was also seen but the exact nature of this relationship requires verification. <br /

How to strengthen an Infant and Young Child Feeding programme in Northern Nigeria

This four-page research summary brief highlights findings and recommendations from operations research into how to strengthen the implementation of an Infant and Young Child Feeding (IYCF) programme and to motivate behaviour change to improve IYCF practices in northern Nigeria. The research found that the IYCF programme was viewed positively by a range of beneficiaries and stakeholders, including family members, traditional birth attendants, IYCF programme community volunteers, health workers and state government officials, because of the perceived visibility of the health benefits, including less episodes of diarrhoea, and consequent savings on health care. Recommendations for the IYCF programme include review strategies for CV training and strengthen supportive supervision, especially in relation to counselling techniques and facilitation of support groups; reinforce and strengthen the use of examples of real healthy children who have been exclusively breastfed to enhance the acceptability of the messages and adoption of the behaviour change; and adopt multiple behaviour change techniques, including food demonstrations and professionally developed mass media