26013 research outputs found
Sort by
A novel critical distance-based homogenised material approach to estimate fatigue lifetime of plain/notched polylactide 3D-printed with different in-fill levels
Get PDFThis study presents a novel approach to predict the fatigue life of plain and notched polylactide (PLA) components 3D-printed with different in-fill levels. The proposed method models 3D-printed PLA with manufacturing voids as a continuous, homogeneous, linear-elastic, isotropic material weakened by equivalent cracks that scale with the size of the voids. This allows for accurate estimation of both plain material strength and notched component fatigue life, considering various in-fill levels. The proposed design method's accuracy and reliability were validated against extensive fatigue testing data from plain and notched specimens, fabricated with varying in-fill levels and raster angles. The strong correlation between predicted and experimental fatigue lives confirms that the method accurately assesses the fatigue strength of additively manufactured PLA components, even without explicitly modelling fabrication voids
How many ways are there to measure a tree? – An experiment in cross-disciplinarity
Get PDFThis article takes a transdisciplinary approach to a relatively simple-sounding task – tree measuring. It asks the question, ‘How many ways are there to measure a tree?’, in order to provoke a discussion of our different ways of knowing. It attempts to engage a reader in thinking about disciplines and what they do. It does so by sharing insights from a project in which diverse scholars, practitioners and children came together for the common purpose of producing engaged knowledge. The experience of reading the article should prompt questions about whose knowledge counts and why, and the value of university research that is engaged and grounded. We conclude with a question of what kinds of measurements matter and why. The article takes the reader through different disciplinary perspectives, from science to social science to poetry, and, in that process, engages with the ‘how’ of disciplines in terms of real-world problems
Factors that influence mental health prescriber decision making in the initiation and maintenance of antipsychotic treatment: a mixed methods systematic review
No full textAn observational study of intergenerational sex differences in mortality in Aotearoa New Zealand
Get PDFInternationally, there are observable sex differentials in mortality in many countries, most notably in affluent countries, with women living longer than men. To understand if this is also the case in Aotearoa New Zealand (NZ), we visualise the precise nature and evolution of sex differentials in mortality by age over time, within a wider context of increasing life expectancy and falling mortality. This allows us to determine if NZ mirrors other affluent countries in having a male/female inequality in mortality, and how the inequality has evolved over several generations in NZ. We use newly available single-year mortality data by sex in NZ to visualise and analyse the sex differentials in mortality using an observational study design. Sex and age-specific mortality data were obtained from the human mortality database from 1948 to 2021 for NZ. The data were then processed to create a smoothed data series using a geometric mean of those two years older and younger as well as aggregating the single-year age groups over 90 into a single category due to small numbers. The processed data was then visualised using a lexis diagram. There are clear patterns of elevated mortality ratios at younger ages (18-30) for males compared to females. The relative difference in mortality inequality between the sexes grew between 1950 and 1980 in NZ, before converging between 2000 and 2020. There is a consistent gap of at least 3 years in life expectancy across the study period by sex. Particularly striking is the longstanding nature of this inequality in mortality by sex in NZ and the relative lack of focus from policymakers. This focus on one country, NZ, allows examination of this specific context to understand how policy changes may have exacerbated or ameliorated trends in male/female mortality inequality
Pattern recognition in SARS cases: insights from t -SNE and k-means clustering applied to COVID-19 symptomatology
Get PDFIntroduction: Despite the end of the SARS-CoV-2 pandemic, the medical field continues to address several lasting effects, the most notable being long COVID. However, COVID-19 presents another specific challenge that complicates diagnosis: the similarity of its symptoms with those of other viral diseases, particularly among various SARS strains. This overlap makes it difficult to identify distinct and meaningful symptom patterns as they develop. This study proposes a dimensionality reduction approach combined with a clustering technique to visually analyse structural similarities among SARS-infected individuals, aiming to determine whether aspects such as case progression and diagnosis impact these patterns. Methods: This analysis utilised the t-Distributed Stochastic Neighbour Embedding (t-SNE) algorithm for dimensionality reduction, combined with Gower's distance to handle categorical data, and k-means clustering. The study focused on symptoms, case progression, and diagnoses of SARS-CoV-2 and unspecified SARS cases using data from the Brazilian SARS dataset for São Paulo State during 2020 and 2021. The process began with a visual analysis aimed at identifying structural patterns in the symptom data, highlighting potential similarities between COVID-19 patients and those diagnosed with unspecified SARS. Following this, an intra-cluster analysis was performed to investigate the common features that defined each cluster, providing insights into shared characteristics among grouped individuals. Results: The analysis revealed that both diagnoses share substantial similarities, particularly in the presence or absence of COVID-19-related symptoms, even when the majority of individuals were diagnosed with unspecified SARS. Discussion: The analysis is crucial, as Brazil was one of the countries most severely affected by the pandemic, experiencing profound impacts across multiple dimensions
Fuelling gold medals: developing a ‘periodised nutrition system’ for elite athletes and applying it in practice
Get PDFThe concept of periodised nutrition is well-established within performance nutrition support to appropriately fuel elite athletes while maximising the adaptative response from training. Despite this, there may still be little planning and integration of training prescription and nutrition between the performance nutritionist and multi-disciplinary team. Consequently, the aim of this case study was to (1) propose a ‘Periodised Nutrition System’ which can be utilised by performance nutrition practitioners when working with athletes, through amalgamating previously published literature, tools, and approaches in the literature; (2) discuss how this can be administered in practice, collaborating with the coach, multidisciplinary team and athlete; (3) present a case study of the proposed ‘Periodised Nutrition System’ and its utilisation with a world class swimmer leading into the 2024 Paris Summer Olympic Games. The ‘Periodised Nutrition System’ presents different ‘performance plates’, quantities of different foods to fit into the ‘performance plates’ to aid recipe development, and how they may practically fit into an athlete’s training periodisation alongside theoretical rationale. The case study demonstrates a ‘real world’ scenario of its utilisation with an elite swimmer, transitioning through three separate performance goals while reducing body mass by 1.9 kg, sum of eight skinfolds by 20.1 mm, predicted fat mass by 2.6 kg and an increase in predicted lean mass by 0.6 kg over a six-week mesocycle. The study highlights that the ‘Periodised Nutrition System’ enables the practitioner to develop a structure to their support, aligning nutritional strategies with the training periodisation of the athlete, allowing for an individualised approach, specific to the athlete’s performance goal(s) and the desired adaptation of a training session
Global, regional, and national burden of suicide, 1990-2021: a systematic analysis for the Global Burden of Disease Study 2021
Get PDFBackgroundDeaths from suicide are a tragic yet preventable cause of mortality. Quantifying the burden of suicide to understand its geographical distribution, temporal trends, and variation by age and sex is an essential step in suicide prevention. We aimed to present a comprehensive set of global, regional, and national estimates of suicide burden.MethodsWe produced estimates of the number of deaths and age-standardised mortality rates of suicide globally, regionally, and for 204 countries and territories from 1990 to 2021, and disaggregated these results by age and sex. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 estimates of deaths attributable to suicide were broken down into two comprehensive categories: those by firearms and those by other specified means. For this analysis, we also produced estimates of mean age at the time of death from suicide, incidence of suicide attempts compared with deaths, and age-standardised rates of suicide by firearm. We acquired data from vital registration, verbal autopsy, and mortality surveillance that included 23 782 study-location-years of data from GBD 2021. Point estimates were calculated from the average of 1000 randomly selected possible values of deaths from suicide by age, sex, and geographical location. 95% uncertainty intervals (UIs) were derived from the 2·5th and 97·5th percentiles from a 1000-draw distribution.FindingsGlobally, 746 000 deaths (95% UI 692 000-800 000) from suicide occurred in 2021, including 519 000 deaths (485 000-556 000) among males and 227 000 (200 000-255 000) among females. The age-standardised mortality rate has declined over time, from 14·9 deaths (12·8-15·7) per 100 000 population in 1990 to 9·0 (8·3-9·6) per 100 000 in 2021. Regionally, mortality rates due to suicide were highest in eastern Europe (19·2 [17·5-20·8] per 100 000), southern sub-Saharan Africa (16·1 [14·0-18·3] per 100 000), and central sub-Saharan Africa (14·4 [11·0-19·1] per 100 000). The mean age at which individuals died from suicide progressively increased during the study period. For males, the mean age at death by suicide in 1990 was 43·0 years (38·0-45·8), increasing to 47·0 years (43·5-50·6) in 2021. For females, it was 41·9 years (30·9-46·7) in 1990 and 46·9 years (41·2-52·8) in 2021. The incidence of suicide attempts requiring medical care was consistently higher at the regional level for females than for males. The number of deaths by suicide using firearms was higher for males than for females, and substantially varied by country and region. The countries with the highest age-standardised rate of suicides attributable to firearms in 2021 were the USA, Uruguay, and Venezuela.InterpretationDeaths from suicide remain variable by age and sex and across geographical locations, although population mortality rates have continued to improve globally since the 1990s. This study presents, for the first time in GBD, a quantification of the mean age at the time of suicide death, alongside comprehensive estimates of the burden of suicide throughout the world. These analyses will help guide future approaches to reduce suicide mortality that consider a public health framework for prevention.FundingBill & Melinda Gates Foundation
Sectoral productivity and real exchange rate effects of remittances: evidence from Nigeria
Get PDFThis study examines the impact of remittances on Nigeria’s real exchange rate and the productivity of its tradable and non-tradable sectors. Drawing on the Dutch Disease Model and the Balassa–Samuelson Effect, the research investigates how remittance inflows influence economic dynamics in a developing, oil-dependent economy. Using annual data from 1980 to 2022 obtained from the World Development Indicators and the Central Bank of Nigeria, the study employs the Autoregressive Distributed Lag (ARDL) approach to analyse both short- and long-term effects. The results reveal a complex relationship that challenges traditional expectations. In the short term, remittances decrease productivity in the tradable sector while improving productivity in the non-tradable sector. However, over time, the tradable sector recovers and experiences sustained gains, whereas the non-tradable sector experiences declines in productivity. Contrary to the Dutch Disease hypothesis, remittances do not exert a long-term impact on the real exchange rate. Other factors, including trade openness, inflation, and terms of trade, also significantly influence the real exchange rate and tradable sector. The findings suggest that Nigeria should avoid over-reliance on remittances as a tool for exchange rate stabilisation. Instead, efforts should prioritise strengthening the capital market, curbing capital flight, and promoting export growth. By shedding new light on the intricate effects of remittances, this study provides valuable insights for policymakers in Nigeria and other developing economies
A multimodal mass spectrometry imaging workflow for ballpoint pen ink analysis and “forgery” detection †
Get PDFInks, including ballpoint, gel, fountain pen, laser toner, inkjet, and security inks, have unique chemical formulations and require specific examination methods based on their properties and the surfaces they are deposited on. Despite the increasing use of digital signatures, ballpoint pens are still used for signing legal documents. Common forensic approaches involving visual examination are crucial in forensic analysis due to their non-destructive nature. However, often their effectiveness can rely on the expertise of the forensic analyst. Other common approaches, such as thin layer chromatography (TLC), require sample extraction which is destructive. This work shows a multimodal imaging workflow, including the application (in order of increasing destructiveness) of Desorption Electrospray Ionisation Mass Spectrometry Imaging (DESI MSI) followed by Matrix Assisted Laser Desorption Ionisation Mass Spectrometry Imaging (MALDI MSI) enabling comprehensive ink and substrate analysis in situ. It is important to note that this work was performed in preparation for a real casework study submitted to our group for analysis. The application of DESI MSI in negative ion mode and MALDI MSI in positive ion mode in principle allows for detection and mapping of diverse chemical species (e.g. dyes, polymers, etc.), providing a comprehensive understanding of the chemical composition of the sample. Indeed, it is well documented that each ionisation technique can enable targeting of different molecular species. Statistical approaches used to interrogate the data, allows in-depth analysis of ink/substrates. This approach offers a robust and reliable methodology, which can complement or offer additional information for forgery determination in forensic cases, where the results obtained from conventional methodologies may have not been successful