JURNAL AGROTEKNOLOGI
Not a member yet
63896 research outputs found
Sort by
A method to remove the influence of fixative concentration on postmortem T2 maps using a kinetic tensor model
No full textFormalin fixation has been shown to substantially reduce T2 estimates, primarily driven by the presence of fixative in tissue. Prior to scanning, post-mortem samples are often placed into a fluid that has more favourable imaging properties. This study investigates whether there is evidence for a change in T2 in regions close to the tissue surface due to fixative outflux into this surrounding fluid. Furthermore, we investigate whether a simulated spatial map of fixative concentration can be used as a confound regressor to reduce T2 inhomogeneity. To achieve this, T2 maps and diffusion tensor estimates were obtained in 14 whole, formalin-fixed post-mortem brains placed in Fluorinert approximately 48 hr prior to scanning. Seven brains were fixed with 10% formalin and seven brains were fixed with 10% neutral buffered formalin (NBF). Fixative outflux was modelled using a proposed kinetic tensor (KT) model, which incorporates voxelwise diffusion tensor estimates to account for diffusion anisotropy and tissue-specific diffusion coefficients. Brains fixed with 10% NBF revealed a spatial T2 pattern consistent with modelled fixative outflux. Confound regression of fixative concentration reduced T2 inhomogeneity across both white and grey matter, with the greatest reduction attributed to the KT model versus simpler models of fixative outflux. No such effect was observed in brains fixed with 10% formalin. Correlations between the transverse relaxation rate R2 and ferritin/myelin proteolipid protein (PLP) histology lead to an increased similarity for the relationship between R2 and PLP for the two fixative types after KT correction
Assessing psychological well-being measures among South African adults in the birth to twenty plus cohort
No full textMental health and substance use disorders account for a significant proportion of disability worldwide. In many developing countries like South Africa, mental healthcare services are often inadequate, forcing people to find their own way of coping with distress and give meaning to their experiences. Therefore, this situation necessitates the conceptualisation and characterisation of the quality-of-life indicators, as well as psychosocial strategies to promote mental well-being. The objectives of this study were to assess the psychometric properties of psychological well-being (PWB) measures in the context of urban Soweto. Data were collected from participants in the Birth to Twenty Plus cohort (n = 1327), in 2018–2019. Exploratory and Confirmatory Factor Analyses conducted for measures of hope, faith, social support, general self-efficacy, and life satisfaction were taken from the National Institutes of Health (NIH) Toolbox Emotion Battery. Cronbach’s alpha was used to determine internal consistencies; discriminant validity was assessed using Pearson correlations. Test-retest reliability analysis was conducted on a subset of participants at three time points which were at least 2 months apart. Overall, the measures of PWB were characterised as having unidimensional factor structures, good model fit indices, high internal consistency and reliability to the paragraph. This study demonstrated that the PWB measures evaluated here are psychometrically sound, and suitable to be used in the South African context
Machine learning to predict the source of campylobacteriosis using whole genome data
No full textCampylobacteriosis is among the world's most common foodborne illnesses, caused predominantly by the bacterium Campylobacter jejuni. Effective interventions require determination of the infection source which is challenging as transmission occurs via multiple sources such as contaminated meat, poultry, and drinking water. Strain variation has allowed source tracking based upon allelic variation in multi-locus sequence typing (MLST) genes allowing isolates from infected individuals to be attributed to specific animal or environmental reservoirs. However, the accuracy of probabilistic attribution models has been limited by the ability to differentiate isolates based upon just 7 MLST genes. Here, we broaden the input data spectrum to include core genome MLST (cgMLST) and whole genome sequences (WGS), and implement multiple machine learning algorithms, allowing more accurate source attribution. We increase attribution accuracy from 64% using the standard iSource population genetic approach to 71% for MLST, 85% for cgMLST and 78% for kmerized WGS data using the classifier we named aiSource. To gain insight beyond the source model prediction, we use Bayesian inference to analyse the relative affinity of C. jejuni strains to infect humans and identified potential differences, in source-human transmission ability among clonally related isolates in the most common disease causing lineage (ST-21 clonal complex). Providing generalizable computationally efficient methods, based upon machine learning and population genetics, we provide a scalable approach to global disease surveillance that can continuously incorporate novel samples for source attribution and identify fine-scale variation in transmission potential
“Unusual, unstable, complicated, unreliable and temporary” reinterpreting the ebb and flow of globalization
No full textIn 1919, John Maynard Keynes wrote his famous tract The Economic Consequences of the Peace. In that work, he anticipated the collapse of the first era of globalization that began in the mid-nineteenth century. He admonished the short-sighted assumption that these years of relative peace and prosperity for many was a permanent norm, interrupted only briefly by the Great War. The diplomatic failures, lapses in leadership, and promotion of narrow interests and vision outlined by Keynes underpinned his prediction of a backslash of economic nationalism, trade protectionism, and recession.
The paper revisits the turning points in the evolution of the global economic system since 1919 by focusing primarily on the evolution of the international monetary system and policy cooperation/coordination. We identify three disruptions and examine how each prompted a change in the underlying ideology about how the international monetary system should organize: World War I, Bretton Woods, 1970s Great Inflation and Managed Floating. Each turning point was characterized by different forms and institutions of cooperation, how rules (either explicit or implicit) were designed and implemented, and the crucial importance of the historical context
Connecting the spots: Leopard print fashion and Panthera pardus conservation
No full textLeopard print is a proliferating fashion design with perpetual, cross–market appeal. But as demand for textiles replicating the leopard’s pattern soar, leopards themselves have disappeared from more than 75 % of the historic range. This study quantifies the fashion interest in leopard print to evaluate whether its popularity reflects an interest in wildlife, specifically in leopards or spotted cats, and whether this has contributed, or has the potential to contribute, to conservation. Global interest is documented and quantified by leveraging user–generated internet data (Google Trends Index), the traditional editorial media (Lexis Nexis), and social media (Instagram). The results suggest little correlation between interest in leopard print and interest (or concern) over leopards in the wild. In this context, conservation and fashion preferences may currently be linked only tenuously by most consumers, presenting a challenge, and potentially great opportunity, if they could be connected in ways making the relationship become mutually beneficial. As one way of achieving this, we conclude by proposing a wildlife royalties funding mechanism whereby the fashion print would benefit leopards through a payment scheme for rights of use for commercial purposes
Extended follow-up of a short total diet replacement programme: results of the Doctor Referral of Overweight People to Low Energy total diet replacement Treatment (DROPLET) randomised controlled trial at 3 years
No full textObjectives
To test the long-term effectiveness of a total diet replacement programme (TDR) for routine treatment of obesity in a primary care setting.
Methods
This study was a pragmatic, two-arm, parallel-group, open-label, individually randomised controlled trial in adults with obesity. The outcomes were change in weight and biomarkers of diabetes and cardiovascular disease risk from baseline to 3 years, analysed as intention-to-treat with mixed effects models.
Interventions
The intervention was TDR for 8 weeks, followed by food-reintroduction over 4 weeks. Behavioural support was provided weekly for 8 weeks, bi-weekly for the next 4 weeks, then monthly for 3 months after which no further support was provided. The usual care (UC) group received dietary advice and behavioural support from a practice nurse for up to 3 months.
Results
Outcome measures were collected from 179 (66%) participants. Compared with baseline, at 3 years the TDR group lost −6.2 kg (SD 9.1) and usual care −2.7 kg (SD 7.7); adjusted mean difference −3.3 kg (95% CI: −5.2, −1.5), p
Conclusions
Treatment of people with obesity with a TDR programme compared with support from a practice nurse leads to greater weight loss which persists to at least 3 years, but there was only evidence of sustained improvements in BP and not in other aspects of cardiometabolic risk
Influenza and respiratory virus surveillance, vaccine uptake, and effectiveness at a time of cocirculating COVID-19: Protocol for the English primary care Sentinel system for 2020-2021
No full textBackground:
The Oxford–Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) and Public Health England (PHE) are commencing their 54th season of collaboration at a time when SARS-CoV-2 infections are likely to be cocirculating with the usual winter infections.
Objective:
The aim of this study is to conduct surveillance of influenza and other monitored respiratory conditions and to report on vaccine uptake and effectiveness using nationally representative surveillance data extracted from primary care computerized medical records systems. We also aim to have general practices collect virology and serology specimens and to participate in trials and other interventional research.
Methods:
The RCGP RSC network comprises over 1700 general practices in England and Wales. We will extract pseudonymized data twice weekly and are migrating to a system of daily extracts. First, we will collect pseudonymized, routine, coded clinical data for the surveillance of monitored and unexpected conditions; data on vaccine exposure and adverse events of interest; and data on approved research study outcomes. Second, we will provide dashboards to give general practices feedback about levels of care and data quality, as compared to other network practices. We will focus on collecting data on influenza-like illness, upper and lower respiratory tract infections, and suspected COVID-19. Third, approximately 300 practices will participate in the 2020-2021 virology and serology surveillance; this will include responsive surveillance and long-term follow-up of previous SARS-CoV-2 infections. Fourth, member practices will be able to recruit volunteer patients to trials, including early interventions to improve COVID-19 outcomes and point-of-care testing. Lastly, the legal basis for our surveillance with PHE is Regulation 3 of the Health Service (Control of Patient Information) Regulations 2002; other studies require appropriate ethical approval.
Results:
The RCGP RSC network has tripled in size; there were previously 100 virology practices and 500 practices overall in the network and we now have 322 and 1724, respectively. The Oxford–RCGP Clinical Informatics Digital Hub (ORCHID) secure networks enable the daily analysis of the extended network; currently, 1076 practices are uploaded. We are implementing a central swab distribution system for patients self-swabbing at home in addition to in-practice sampling. We have converted all our primary care coding to Systematized Nomenclature of Medicine Clinical Terms (SNOMED CT) coding. Throughout spring and summer 2020, the network has continued to collect specimens in preparation for the winter or for any second wave of COVID-19 cases. We have collected 5404 swabs and detected 623 cases of COVID-19 through extended virological sampling, and 19,341 samples have been collected for serology. This shows our preparedness for the winter season.
Conclusions:
The COVID-19 pandemic has been associated with a groundswell of general practices joining our network. It has also created a permissive environment in which we have developed the capacity and capability of the national primary care surveillance systems and our unique public health institute, the RCGP and University of Oxford collaboration
Enhancing security in VLC systems through beamforming
No full textThis paper proposes a novel zero-forcing (ZF) beamforming strategy that can simultaneously cope with active and passive eavesdroppers (EDs) in visible light communication systems. A related optimization problem is formulated to maximize the signal-to-noise ratio (SNR) of the legitimate user (UE) while suppressing the SNR of active ED to zero and constraining the average SNR of passive EDs. The proposed beamforming directs the transmission along a particular eigenmode related to the null space of the active ED channel and the intensity of the passive ED point process. An inverse free preconditioned Krylov subspace projection method is used to find the eigenmode. The numerical results show that the proposed ZF beamforming scheme yields better performance relative to a traditional ZF beamforming scheme in the sense of increasing the SNR of the UE and reducing the secrecy outage probability
Preconception and diabetes information (PADI) app for women with pregestational diabetes: a feasibility and acceptability study
No full textDiabetes mellitus increases the risk of adverse maternal and fetal outcomes. Preconception care is vital to minimise complications; however, preconception care service provision is hindered by inadequate knowledge, resources and care fragmentation. Mobile health technology, particularly smartphone apps, could improve preconception care and pregnancy outcomes for women with diabetes. The aim of this study is to co-create a preconception and diabetes information app with healthcare professionals and women with diabetes and explore the feasibility, acceptability and preliminary effects of the app. A mixed-methods study design employing questionnaires and semi-structured interviews was used to assess preliminary outcome estimates (preconception care knowledge, attitudes and behaviours), and user acceptability. Data analysis included thematic analysis, descriptive statistics and non-parametric tests. Improvements were recorded in knowledge and attitudes to preconception care and patient activation measure following the 3-month app usage. Participants found the app acceptable (satisfaction rating was 72%), useful and informative. The app’s usability and usefulness facilitated usage while manual data input and competing priorities were barriers which participants felt could be overcome via personalisation, automation and use of daily reminders. This is the first study to explore the acceptability and feasibility of a preconception and diabetes information app for women with diabetes. Triangulated data suggest that the app has potential to improve preconception care knowledge, attitudes and behaviours. However, in order for women with DM to realise the full potential of the app intervention, particularly improved maternal and fetal outcomes, further development and evaluation is required
Different B cell subpopulations show distinct patterns in their IgH repertoire metrics
No full textSeveral human B cell subpopulations are recognised in the peripheral blood, which play distinct roles in the humoral immune response. These cells undergo developmental and maturational changes involving VDJ recombination, somatic hypermutation and class switch recombination, altogether shaping their immunoglobulin heavy chain (IgH) repertoire. Here, we sequenced the IgH repertoire of naïve, marginal zone, switched and plasma cells from 10 healthy adults along with matched unsorted and in silico separated CD19+ bulk B cells. Using advanced bioinformatic analysis and machine learning, we show that sorted B cell subpopulations are characterised by distinct repertoire characteristics on both the individual sequence and the repertoire level. Sorted subpopulations shared similar repertoire characteristics with their corresponding in silico separated subsets. Furthermore, certain IgH repertoire characteristics correlated with the position of the constant region on the IgH locus. Overall, this study provides unprecedented insight over mechanisms of B cell repertoire control in peripherally circulating B cell subpopulations