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1.
Bull Math Biol ; 84(7): 72, 2022 06 10.
Article in English | MEDLINE | ID: mdl-35689123

ABSTRACT

Multiscale modeling of marine and aerial plankton has traditionally been difficult to address holistically due to the challenge of resolving individual locomotion dynamics while being carried with larger-scale flows. However, such problems are of paramount importance, e.g., dispersal of marine larval plankton is critical for the health of coral reefs, and aerial plankton (tiny arthropods) can be used as effective agricultural biocontrol agents. Here we introduce the open-source, agent-based modeling software Planktos targeted at 2D and 3D fluid environments in Python. Agents in this modeling framework are relatively tiny organisms in sufficiently low densities that their effect on the surrounding fluid motion can be considered negligible. This library can be used for scientific exploration and quantification of collective and emergent behavior, including interaction with immersed structures. In this paper, we detail the implementation and functionality of the library along with some illustrative examples. Functionality includes arbitrary agent behavior obeying either ordinary differential equations, stochastic differential equations, or coded movement algorithms, all under the influence of time-dependent fluid velocity fields generated by computational fluid dynamics, experiments, or analytical models in domains with static immersed mesh structures with sliding or sticky collisions. In addition, data visualization tools provide images or animations with kernel density estimation and velocity field analysis with respect to deterministic agent behavior via the finite-time Lyapunov exponent.


Subject(s)
Mathematical Concepts , Models, Biological , Coral Reefs , Locomotion , Plankton , Systems Analysis
2.
J Plast Reconstr Aesthet Surg ; 71(12): 1777-1784, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30245017

ABSTRACT

Despite the potential negative impact of facial palsy, major gaps in understanding persist surrounding the treatment and care of those affected. This collaborative three-round Delphi process aimed to identify priorities for future facial palsy research, from the perspective of clinicians, researchers, patients and carers. It also determined whether the research priorities of patients and carers aligned with those of health professionals and researchers. In Round 1, participants (n = 85) were asked to generate research questions by focus groups or an online or postal survey. In Rounds 2 (n = 72) and 3 (n = 78), participants were asked to rate the priorities identified on a 5-point ordinal scale. Thirty-six questions reached the definition of 'high priority' consensus. Seven of each groups' top ten research priorities were shared. Prioritised questions included the provision and pathways of care, the psychosocial impact of living with facial palsy and the effective management of side effects. Establishing the research priorities in the field of facial palsy is a significant first step in ensuring that the future research agenda is focussed on topics that are considered important by both patients and health professionals.


Subject(s)
Facial Paralysis/therapy , Research , Attitude of Health Personnel , Attitude to Health , Caregivers/psychology , Consensus , Delphi Technique , Facial Paralysis/psychology , Female , Focus Groups , Humans , Male , Middle Aged , Research Personnel/psychology , United Kingdom
3.
Article in English | MEDLINE | ID: mdl-23020628

ABSTRACT

Esters of 2 - and 3-monochloropropane-1,2-diol (MCPD) and glycidol esters are important contaminants of processed edible oils used as foods or food ingredients. This review describes the occurrence and analysis of MCPD esters and glycidol esters in vegetable oils and some other foods. The focus is on the analytical methods based on both direct and indirect methods. Methods of analysis applied to oils and lipid extracts of foods have been based on transesterification to free MCPD and determination by gas chromatography-mass spectrometry (indirect methods) and by high-performance liquid chromatography-mass spectrometry (direct methods). The evolution and performance of the different methods is described and their advantages and disadvantages are discussed. The application of direct and indirect methods to the analysis of foods and to research studies is described. The metabolism and fate of MCPD esters and glycidol esters in biological systems and the methods used to study these in body tissues studies are described. A clear understanding of the chemistry of the methods is important when choosing those suitable for the desired application, and will contribute to the mitigation of these contaminants.


Subject(s)
Carcinogens/toxicity , Epoxy Compounds/chemistry , Esters/toxicity , Food Analysis/methods , Food Contamination , Plant Oils/chemistry , Propanols/chemistry , Carcinogens/chemistry , Esters/chemistry
4.
Food Addit Contam ; 24 Suppl 1: 47-59, 2007.
Article in English | MEDLINE | ID: mdl-17687699

ABSTRACT

In March 2006, a joint workshop was organized by the European Commission and the Confederation of EU Food and Drink Industries (CIAA) to discuss current knowledge and achievements in the reduction of acrylamide levels. This paper focuses on the progress made with cereal products. At present, the reduction options available are applicable to a limited number of cereal products and are product-specific. The following are the most promising: * Adjustment of time and temperature during baking. * Extend fermentation times where feasible. * Substitution of ammonium bicarbonate with alternatives where feasible. * Avoid or minimise use of reducing sugars where possible. * Maintenance of uniform control of the colour and avoidance of very high baking temperature where possible. The most promising near-term technical solution is the use of asparaginase. This enzyme has the potential to achieve a 60-90% reduction for some products made from dough or batter, which can be held for a time. In the longer term, the optimisation of agronomy and plant breeding for wheat has the potential to reduce acrylamide in all foods on any scale, whether domestic or industrial. Importantly, nutritional and toxicological issues, other than acrylamide, must also be considered so as to ensure that the steps taken to reduce acrylamide levels do not have other adverse effects on diet.


Subject(s)
Acrylamide/analysis , Carcinogens, Environmental/analysis , Edible Grain/chemistry , Food Contamination/analysis , Asparaginase/metabolism , Asparagine/analysis , Bread/analysis , Cooking/methods , Fermentation , Food Contamination/prevention & control , Food Handling/methods , Nutrition Assessment , Risk Assessment/methods
5.
Food Addit Contam ; 22(7): 616-23, 2005 Jul.
Article in English | MEDLINE | ID: mdl-16019837

ABSTRACT

A major precursor of 3-monochloropropanediol (3-MCPD) in leavened cereal products is glycerol, which is formed as a natural by-product of yeast fermentation. However, yeast metabolism is affected by stresses such as low osmotic pressure from, for example, the incorporation of sugar or salt in the dough recipe. Tests with model doughs have shown that glycerol production was proportional to yeast mass and limited by available sugars, but that high levels of yeast inhibited 3-MCPD formation. The yeast fraction responsible for the inhibition of 3-MCPD in model dough was shown to be the soluble cytosol proteins, and the inhibition mechanism could be explained by the known reactions of 3-MCPD and/or its precursors with ammonia/amino acids (from yeast proteins). Added glucose did not increase the production of glycerol by yeast but it did promote the generation of 3-MCPD in cooked doughs. The latter effect was attributed to the removal of 3-MCPD inhibitors such as ammonia and amino acids by their reactions with added glucose (e.g. Maillard). The thermal generation of organic acids from added glucose also reduced the pH of cooked doughs, so the effect of pH and short-chain organic acids on 3-MCPD generation in dough was measured. There was a good correlation between initial dough pH and the level of 3-MCPD generated. The effect was weaker than that predicted by simple kinetic modelling, suggesting that the involvement of H+ and/or the organic acid was catalytic. The results showed that modifications to dough recipes involving the addition of reducing sugars and/or organic acids can have a significant impact on 3-MPCD generation in bakery products.


Subject(s)
Flour , Glycerol/analogs & derivatives , Yeasts/metabolism , Amino Acids/metabolism , Cooking , Food Contamination , Food Handling/methods , Fungal Proteins/metabolism , Glucose/metabolism , Glycerol/antagonists & inhibitors , Glycerol/metabolism , Hot Temperature , Hydrogen-Ion Concentration , Models, Biological , alpha-Chlorohydrin
6.
Food Addit Contam ; 19(7): 619-31, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12113657

ABSTRACT

A critical review of the occurrence of 3-chloro-propane-1,2-diol (3-MCPD) in foods not known to contain hydrolysed vegetable proteins is presented. The review covers the properties and chemistry of 3-MCPD and the current methods of analysis in foodstuffs. The results of UK surveys of 3-MCPD occurrence in both retail foods and commercial food ingredients are discussed with particular reference to cereal, meat and dairy products. The possible mechanisms for the formation and decay of 3-MCPD in foods are suggested. The review does not cover the detailed toxicology of 3-MCPD and its occurrence in hydrolysed vegetable proteins, which have been considered elsewhere, nor possible issues such as in-vivo formation.


Subject(s)
Food Contamination/analysis , alpha-Chlorohydrin/analysis , Edible Grain/chemistry , Food Analysis/methods , Food Handling , Humans , alpha-Chlorohydrin/chemistry
7.
Food Addit Contam ; 19(1): 15-21, 2002 Jan.
Article in English | MEDLINE | ID: mdl-11817372

ABSTRACT

A survey of 3-monochloropropane-1,2-diol (3-MCPD) in a range of food ingredients available in the UK is reported. The survey was conducted for the Food Standards Agency to assess the progress made by manufacturers in reducing levels of 3-MCPD in food ingredients in line with the UK Food Advisory Committee's recommendation, i.e. that 3-MCPD is undetectable (i.e. < 0.010 mg kg(-1) in foods and where technologically feasible, in food ingredients as well. Sixty-three samples of food ingredients available in the UK were analysed using a validated method of analysis with a limit of quantification of 0.010 mg kg(-1). Samples included breadcrumbs, caramels, enzyme-hydrolysed vegetable proteins, gelatines, malt products (malt extracts, malt flours and other malt-based in gredients), meat extracts, modified starches, and yeast extracts. 3-MCPD was not quantified in 49 (78%) of the samples analysed. The remaining 14 samples (22%) contained levels of 3-MCPD between 0.014 and 0.488 mg kg(-1), the highest level being in a maize yellow dextrin. Malt-based ingredients accounted for the majority of samples containing 3-MCPD > 0.010 mg kg(-1), with nine of these 24 samples (38%) having quantifiable levels of 3-MCPD.


Subject(s)
Chemosterilants/analysis , Food Contamination/analysis , alpha-Chlorohydrin/analysis , Edible Grain/chemistry , Food Analysis/methods , Humans , United Kingdom
8.
J Digit Imaging ; 12(2 Suppl 1): 119-21, 1999 May.
Article in English | MEDLINE | ID: mdl-10342186

ABSTRACT

We regard the delivery of radiological information as an interactive multimedia report. We use a multimedia report model based on Extensible Markup Language (XML), rather than a traditional workstation model. Others have suggested a similar document-based approach. This display presentation includes image-related and text-based information and may contain interactive components (e.g., window, level and zoom). Using XML as a foundation for this multimedia presentation, we achieve flexibility and platform independence at a lower cost. XML allows for the separation of content and form. Content information, defined as elements (e.g., images, radiologic reports, and demographic information), is treated as independent information objects. The behavior of the elements can be changed for different users and tasks. In addition, by separating format detail from content, the appearance of the elements within the report can be modified. XML does not replace existing standards (i.e., Digital Imaging and Communications in Medicine [DICOM], Transmission Control Protocol/Internet Protocol [TCP/IP]). Instead, it provides a powerful framework that is used in combination with existing standards to allow system designers to modify display characteristics based on user need. We describe our application of XML to the clinical display of radiologic information.


Subject(s)
Data Display , Diagnostic Imaging , Multimedia , Radiology Information Systems , Computer Systems , Costs and Cost Analysis , Data Display/economics , Database Management Systems , Humans , Information Storage and Retrieval , Multimedia/classification , Multimedia/economics , Programming Languages , Systems Integration
9.
Food Addit Contam ; 15(4): 451-65, 1998.
Article in English | MEDLINE | ID: mdl-9764216

ABSTRACT

The EC Scientific Committee for Foods and more recently the Food Advisory Committee in the UK have proposed that levels of 3-chloro-1,2-propanediol (3-MCPD) in foods and ingredients should be reduced to the lowest possible. This paper reports on the development of methods for the determination of parts-per-billion (microgram/kg) levels of 3-MCPD in hydrolysed vegetable protein (HVP), flour, bread, meat and starch products using gas chromatography/ion-trap tandem mass spectrometry (GC/ITMS/MS). Mass spectrometer conditions for detecting 3-MCPD and the stable isotope internal standard (3-chloro-1,2-propandiol-d7) were established. Candidate extraction methods were initially evaluated for recovery and repeatability by spiking selected commodities at a level of 100 micrograms/kg. Extracts of ingredients and foods prepared by the candidate extraction methods were examined by GC/ITMS/MS using samples spiked at a level of 25 micrograms/kg. The results showed that detection limits of between 3 and 5 micrograms/kg could be achieved for all commodities.


Subject(s)
Carcinogens/analysis , Food Contamination/analysis , Plant Proteins, Dietary/chemistry , alpha-Chlorohydrin/analysis , Bread , Chromatography, Gas , Flour , Humans , Isomerism , Mass Spectrometry , Meat , Reproducibility of Results , Sensitivity and Specificity , Starch
10.
J Appl Behav Anal ; 17(4): 553-7, 1984.
Article in English | MEDLINE | ID: mdl-16795682

ABSTRACT

Many experimenters and practitioners regard eye contact between instructor and learner as a facilitator, if not a prerequisite, to the effective instruction of sighted people. Without scientifically supporting the practice of demanding eye contact, experimenters, nonetheless, advocate its use and offer a variety of procedures to promote its acquisition. To justify the widespread use of demanded eye contact and to explain its role functionally, one experiment and data from six replications with nine subjects are presented. The primary experiment provides an empirical base for the training of eye contact prior to instruction. In a multiple-baseline design across two students demanded eye contact resulted in levels of compliance that were double and triple those of baseline. A tentative functional analysis of demanded eye contact is presented, followed by a discussion of the relationship of eye contact to attending.

11.
s.l; American Public Health Association; 1974. 129 p.
Monography in English | MedCarib | ID: med-14648
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