Showing papers by "University of Bedfordshire published in 2001"
TL;DR: The minimum inhibitory concentration of oregano essential oil and two of its principle components, i.e. thymol and carvacrol, against Pseudomonas aeruginosa and Staphylococcus aureus was assessed by using an innovative technique.
Abstract: Aims: The minimum inhibitory concentration (MIC) of oregano essential oil (OEO) and two of its principle components, i.e. thymol and carvacrol, against Pseudomonas aeruginosa and Staphylococcus aureus was assessed by using an innovative technique. The mechanism of action of the above substances was also investigated. Methods and Results: The applied technique uses 100-well microtitre plate and collects turbidimetric growth data. To produce the inhibition profiles, a wide range of concentrations were tested for each of the three compounds, as well as for carvacrol‐thymol mixtures. Following a specific mathematical analysis of the observed inhibition profiles from all compounds, it was suggested that mixtures of carvacrol and thymol gave an additive effect and that the overall inhibition by OEO can be attributed mainly to the additive antimicrobial action of these two compounds. Addition of low amounts of each additive: (a) increased permeability of cells to the nuclear stain EB, (b) dissipated pH gradients as indicated by the CFDA-SE fluorescent probe irrespective of glucose availability and (c) caused leakage of inorganic ions. Conclusions: Mixing carvacrol and thymol at proper amounts may exert the total inhibition that is evident by oregano essential oil. Such inhibition is due to damage in membrane integrity, which further affects pH homeostasis and equilibrium of inorganic ions. Significance and Impact of the Study: The knowledge of extent and mode of inhibition of specific compounds, which are present in plant extracts, may contribute to the successful application of such natural preservatives in foods, since certain combinations of carvacrol‐ thymol provide as high inhibition as oregano essential oil with a smaller flavour impact.
2,207 citations
TL;DR: The current nursing shortage, high hospital nurse job dissatisfaction, and reports of uneven quality of hospital care are not uniquely American phenomena. as mentioned in this paper presents reports from 43,000 nurses from more than 700 hospitals in the United States, Canada, England, Scotland, and Germany in 1998-1999.
Abstract: The current nursing shortage, high hospital nurse job dissatisfaction, and reports of uneven quality of hospital care are not uniquely American phenomena. This paper presents reports from 43,000 nurses from more than 700 hospitals in the United States, Canada, England, Scotland, and Germany in 1998-1999. Nurses in countries with distinctly different health care systems report similar shortcomings in their work environments and the quality of hospital care. While the competence of and relation between nurses and physicians appear satisfactory, core problems in work design and workforce management threaten the provision of care. Resolving these issues, which are amenable to managerial intervention, is essential to preserving patient safety and care of consistently high quality.
1,539 citations
TL;DR: This study confirms the importance of cardiovascular disease as the major cause of death in people with both types of diabetes and confirms the low excess mortality in the Tokyo cohort could have implications for the possible reduction of the burden of mortality associated with diabetes in other parts of the world.
Abstract: We aimed to examine the mortality rates, excess mortality and causes of death in diabetic patients from ten centres throughout the world. A mortality follow-up of 4713 WHO Multinational Study of Vascular Disease in Diabetes (WHO MSVDD) participants from ten centres was carried out, causes of death were ascertained and age-adjusted mortality rates were calculated by centre, sex and type of diabetes. Excess mortality, compared with the background population, was assessed in terms of standardised mortality ratios (SMRs) for each of the 10 cohorts. Cardiovascular disease was the most common underlying cause of death, accounting for 44 % of deaths in Type I (insulin-dependent) diabetes mellitus and 52 % of deaths in Type II (non-insulin-dependent) diabetes mellitus. Renal disease accounted for 21 % of deaths in Type I diabetes and 11 % in Type II diabetes. For Type I diabetes, all-cause mortality rates were highest in Berlin men and Warsaw women, and lowest in London men and Zagreb women. For Type II diabetes, rates were highest in Warsaw men and Oklahoma women and lowest in Tokyo men and women. Age adjusted mortality rates and SMRs were generally higher in patients with Type I diabetes compared with those with Type II diabetes. Men and women in the Tokyo cohort had a very low excess mortality when compared with the background population. This study confirms the importance of cardiovascular disease as the major cause of death in people with both types of diabetes. The low excess mortality in the Japanese cohort could have implications for the possible reduction of the burden of mortality associated with diabetes in other parts of the world. [Diabetologia (2001) 44 [Suppl 2]: S 14–S 21]
1,170 citations
TL;DR: In this paper, an overview of recent work on some particular aspects of the behavior of biopolymer solution and gel mixtures, the focus being on aspects that are of particular relevance to the materials found in food systems.
261 citations
Book•
14 Dec 2001TL;DR: The concept of the "Role Model" was introduced by as mentioned in this paper, who argued that the poxy swan is the wrong way in a poxy swimming pool and pointed out the need for a role model.
Abstract: 1. Introduction. Part One: The Tales they Tell of Men... 2. Discourses of crisis in masculinity 3. The developments of media sports 4. Heroes and stars 5. Narrativity and biography 6. Sporting masculinities Part Two: From Sporting Print to Satellite 7. The birth of the sport star: Pre War Fame 8. Good Boys: Stars, Nations and Respectability in the 1950s 9. Pretty Boys, the 1960s and pop culture 10. Bad boys and the work ethic Part Three: The Restless Vortex of Celebrity 11. Celebration, punishment, redemption and self-discipline 12. Moralities, masculinities and violence 13. Identities: "race", nation and masculinity 14. Performances, appearances, identitites and post-modernities 15. Voretextuality and conspicious consumption 16. Conclusion: So what if the poxy swan is the wrong way? Appendices. 1. Bibliographical Notes 2. The concept of the "Role Model" - critical notes 3. Notes on the Methodological Issues. Bibliography.
257 citations
TL;DR: In this paper, a review of research on occupational stressors and strains amongst academics working in UK universities is provided, with four major themes considered: (a) the prevalence of self-reported occupational stress and strain; (b) the features of academic work that are potentially stressful; (c) the impact of these stressors; and (d) observed differences between gender, age and grade.
Abstract: This paper reviews research on occupational stressors and strains amongst academics working in UK universities. A brief history of research conducted in this field in the USA, Australia and the UK is provided. Four major themes are considered: (a) the prevalence of self-reported occupational stress and strain; (b) the features of academic work that are potentially stressful; (c) the impact of these stressors; and (d) observed differences between gender, age and grade. Studies reviewed here suggest that, in comparison to other professionals and community samples, academic staff experience less job satisfaction and extremely low levels of psychological health. Potential explanations for the rise in levels of self-reported stressors and strains are explored, as are the implications of the research findings reported here. Some recommendations for future research are highlighted.
219 citations
TL;DR: A complementary battery of short- and long-term in vitro and in vivo assays that assess both receptor and non-receptor mediated mechanisms of action seems the most appropriate way at present of assessing the potential endocrine disrupting activities of chemicals.
161 citations
TL;DR: It is concluded that coagulation with downstream microfiltration offers a cost-effective means of removing natural organic matter, achieving a THMFP removal of around 80% at the optimum dose.
159 citations
TL;DR: The contribution of the media to the creation of the climate of fear, blame and mistrust which seems to have become endemic within the field of child protection is explored in this article, which suggests that damaging distortions have been introduced into the child protection system as a result of the defensive responses of the relevant authorities at both national and local level.
Abstract: Summary During the 1970s, 1980s and 1990s, sensationalist coverage of a series of celebrated child abuse scandals in England and Wales resulted in the repeated vilification in the mass media of those child welfare agencies deemed culpable for the deaths of the children involved. This paper explores the contribution of the media to the creation of the climate of fear, blame and mistrust which seems to have become endemic within the field of child protection. It suggests that damaging distortions have been introduced into the child protection system as a result of the defensive responses of the relevant authorities at both national and local level to the media onslaught. A more strategic approach to understanding and managing media coverage of this difficult field is outlined.
154 citations
TL;DR: Fluorescent staining methods used in the authors' laboratories have led to a functional classification of the physiological state of individual microbial cells based on reproductive activity, metabolic activity, and membrane integrity.
Abstract: Background
When using traditional microbiological techniques to monitor cell proliferation and viability, stressed, sublethally injured, or otherwise “viable but nonculturable” cells often go undetected. Because of this, such cells often are not considered by mathematical models used to predict bioprocess performance on scale-up and inaccuracies result. Therefore, analytical techniques, decoupled from postsampling growth, are desirable to rapidly monitor individual cell physiologic states during microbial fermentations.
Methods
Microbial cells, including Escherichia coli, Rhodococus sp., and Sacharomyces cerevisiae, were taken at various stages from a range of fermentation processes and stained with one of three mixtures of fluorescent stains: rhodamine 123/propidium iodide, bis-oxonol/propidium iodide, or bis-oxonol/ethidium bromide/propidium iodide. An individual cell's physiologic state was assessed with a Coulter Epics Elite analyzer based on the differential uptakes of these fluorescent stains.
Results
It was possible to resolve an individual cell's physiologic state beyond culturability based on the functionality of dye extrusion pumps and the presence or absence of an intact polarized cytoplasmic membrane, enabling assessment of population heterogeneity. This approach allows the simultaneous differentiation of at least four functional subpopulations in microbial populations.
Conclusions
Fluorescent staining methods used in our laboratories have led to a functional classification of the physiological state of individual microbial cells based on reproductive activity, metabolic activity, and membrane integrity. We have used these techniques extensively for monitoring the stress responses of microorganisms in such diverse areas as bioremediation, biotransformation, food processing, and microbial fermentation; microbial fermentation is discussed in this article. Cytometry 44:179–187, 2001. © 2001 Wiley-Liss, Inc.
147 citations
TL;DR: Support is provided for a model of germination in which, in order to initiate germination, germinant has to permeate the coat and cortex of the spore and bind to a germination receptor located in the inner membrane.
Abstract: A spore germination response requires the interaction of the germinant with a specific receptor on the spore (17). The gerA operon of Bacillus subtilis, required for germination in l-alanine (19, 33, 34), was the first characterized of a family of operons that is present in all spore formers so far examined; multiple family members are present in each genome. B. subtilis also contains the gerB (6) and gerK (10) operons required for germination in the alternative germinative combination of an amino acid, such as l-alanine or l-asparagine, in combination with sugars. Both gerA and gerB operons have been shown to be expressed in the developing forespore under the control of sigma G-associated RNA polymerase (5, 7). The gerA operon encodes three proteins: GerAA, which is predicted to comprise both hydrophobic and hydrophilic domains; GerAB, which is predicted to be an integral membrane protein and is a member of the single-component amino acid/polyamine/organocation transporter superfamily (11); and GerAC, a predicted lipoprotein. Spores of triple mutants in the gerA, gerB, and gerK operons will not germinate on nutrient media (22). Two other homologous operons in the B. subtilis genome (12) presumably encode components that respond to as-yet-unidentified germinants. In addition to the five operons in B. subtilis, there are homologues of demonstrated importance to inosine germination in B. cereus (4) and to germination in macrophages, encoded in the virulence cluster of plasmid pXO1 of B. anthracis (8). The levels of expression from gerA-lacZ fusions are very low and are only detectable by using fluorogenic substrates for β-galactosidase (7). If the Ger proteins are expressed only at a low level during sporulation, it is not likely to be practicable to detect the location of these proteins in spores by immunogold labeling. Fractionation of spores provides an alternative approach to defining their position(s) in the spore. The definition of the location of these proteins in the spore is of crucial importance to our formulation of models for the mechanism of spore germination.
TL;DR: A prevalidation study on in vitro tests for acute skin irritation was conducted during 1999 and 2000 as discussed by the authors, which specifically addressed aspects of: protocol refinement (phase I), protocol transfer (phase II), and protocol performance (phase III), in accordance with the prevalidation scheme defined by the European Centre for the Validation of Alternative Methods.
TL;DR: The assembly and use of a 1877-member microarray representing cDNA clones from a range of prostate cancer stages and grades, precursor lesions and normal tissue is described, and analysis of expression patterns identified many up-regulated transcripts.
Abstract: The identification of novel genes or groups of genes expressed in prostate cancer may allow earlier diagnosis or more accurate staging of the disease. We describe the assembly and use of a 1877-member microarray representing cDNA clones from a range of prostate cancer stages and grades, precursor lesions and normal tissue. Using labelled cDNA from tumour samples obtained from TURP or radical prostatectomy, analysis of expression patterns identified many up-regulated transcripts. Cell lines were found to over-express fewer genes than diseased tissue samples. 17 known genes were found to over-express more than 4-fold in 4 or more cancers out of 15 cancers. Only 2 genes were over-expressed in 6 out of 15 cancers or more, whilst no genes were consistently found to be over-expressed in all cancer samples. Novel prostate cancer associations for several well characterized genes or full length cDNAs were identified, including PLRP1, JM27, human UbcM2, dynein light intermediate chain 2 and human homologue of rat sec61. Novel associations with high-grade PIN include: breast carcinoma fatty acid synthase and cDNA DKFZp434B0335. We shortlist and discuss the most significant over-expressed genes in prostate cancer and PIN, and highlight expression differences between malignant and benign samples. © 2001 Cancer Research Campaign http://www.bjcancer.com
TL;DR: The results show that CYP-dependent metabolism can be preserved or even activated in immortalized keratinocytes, and indicate presence of several CYPs of which some may contribute to significant xenobiotic metabolism in human buccal epithelium.
Abstract: Constituents in food and fluids, tobacco chemicals and many drugs are candidates for oral absorption and oxidative metabolism. On this basis, the expression of cytochrome P450 isozymes (CYPs) and the conversion of CYP substrates were analysed in reference to buccal mucosa. A RT-PCR based analysis of human buccal tissue from 13 individuals demonstrated consistent expression of mRNA for the CYPs 1A1, 1A2, 2C, 2E1, 3A4/7 and 3A5. CYP 2D6 was expressed in six out of the 13 specimens, whereas all samples were negative for 2A6 and 2B6. Serum-free monolayer cultures of the Siman virus 40 large T-antigen-immortalized SVpgC2a and the carcinoma SqCC/Y1 buccal keratinocyte lines expressed the same CYPs as tissue except 3A4/7 and 3A5 (SVpgC2a), and 2C, 2D6 and 3A4/7 (SqCC/Y1). Dealkylation of ethoxyresorufin and methoxyresorufin in both normal and transformed cells indicated functional 1A1 and 1A2, respectively. SVpgC2a showed similar activity as normal keratinocytes for both substrates, whereas SqCC/Y1 showed about 2-fold lower 7-ethoxyresorufin O-deethylation and 7-methoxyresorufin O-demethylation activities. SVpgC2a showed detectable and many-fold higher activity than the other cell types towards chlorzoxazone, a substrate for 2E1. Absent or minute catalytic activity of 2C9, 2D6 and 3A4 in the various cell types was indicated by lack of detectable diclofenac, dextromethorphan and testosterone metabolism (<0.2-0.5 pmol/min/mg). Metabolic activation of the tobacco-specific N-nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and the mycotoxin aflatoxin B1 (AFB1) to covalently bound adducts was indicated by autoradiographic analysis of both monolayer and organotypic cultures of SVpgC2a. In contrast, SqCC/Y1 showed lower or absent metabolic activity for these substrates. Finally, measurements of various non-reactive AFB1 metabolites indicated rates of formation <0.1 pmol/min/mg in both normal and transformed cells. The results indicate presence of several CYPs of which some may contribute to significant xenobiotic metabolism in human buccal epithelium. Notably, metabolic activation of AFB1 was not previously implicated for oral mucosa. Further, the results show that CYP-dependent metabolism can be preserved or even activated in immortalized keratinocytes. Metabolic activity in SVpgC2a under both monolayer and organotypic culture conditions suggests that this cell line may be useful to pharmaco-toxicological and carcinogenesis studies.
TL;DR: The results strongly suggest that different mechanisms of hepatotoxicity may be associated with specific patterns of gene expression, while some genes associated with common cellular responses may be useful as early markers of toxicity.
TL;DR: The data suggest that the mechanism of glucocorticoid action in suppressing interleukin-1 beta-stimulated GM-CSF release in A549 cells may involve modulation of CBP-mediated histone-acetylase activity and DNA methylation.
TL;DR: In this paper, the authors used tracer gas and pressure difference across ventilation openings to estimate the ammonia emission rate in cattle buildings in the United Kingdom and found a good correlation between the measured and the actual release rates.
TL;DR: In this paper, the authors consider the different approaches available at a local level to meet one of the more pressing targets in the Directive, which aims to reduce ultimately the disposal of biodegradable municipal waste (BMW) in the UK to 35% of 1995 levels.
Abstract: Despite its lowly position on the waste hierarchy, landfill remains the predominant method of disposal in the UK. It currently accounts for disposal of 85% of municipal solid waste, despite the presence of national policies and targets to increase recycling and divert waste from landfill. However, the implementation of the EU Landfill Directive into the UK legislation in 2001 will place increasing pressure on the householder to participate in more sustainable waste management practices. This research will consider the different approaches available at a local level to meet one of the more pressing targets in the Directive — to reduce ultimately the disposal of biodegradable municipal waste (BMW) in the UK to 35% of 1995 levels. Significant changes in practice are required if the targets are to be met. This will require an increase in the availability of alternative options such as recycling and composting and place greater pressure on the householder to respond positively. At present there is little incentive for the householder in the UK to divert waste from disposal, as there is no penalty for non-participation in recycling schemes, and ease of disposal has generated apathy towards more time consuming alternative management options. International case studies have shown that direct charging is one approach that can produce dramatic results in terms of increased recycling and waste minimisation. Pay-as-you-throw (PAYT) schemes place responsibility on the householder to manage their waste in a more sustainable manner, with economics being the motivator. Reluctance to incorporate such an approach, and its applicability in the UK, form the focus of discussion and alternatives are considered with respect to changing behaviour, increasing participation and meeting the BMW waste targets.
TL;DR: In this paper, the authors examine the strategies developed within and around government to achieve a homogeneous youth justice service in England and Wales and examine the ways in which political imperatives...
Abstract: This article examines the strategies developed within and around government to achieve a homogeneous youth justice service in England and Wales. It examines the ways in which political imperatives ...
TL;DR: The results of the present study support the utility of EC3 determinations in the LLNA as a measure of the relative potency of a contact allergen.
Abstract: The murine local lymph node assay (LLNA) assesses skin sensitization potential as a function of proliferative responses induced in lymph nodes draining the site of topical exposure to test chemical. It has been shown that interpolation of LLNA dose-response data to define the concentration of test chemical required to induce a 3-fold stimulation of proliferation (EC3) offers the prospect of a quantitative index of the relative potency of a contact allergen. Initial studies have demonstrated that there exists a strong (inverse) correlation between EC3 values and contact allergenic potency in humans. Thus, materials with a low EC3 value were more potent contact allergens in humans. However, it is necessary to examine a wide range of allergens to demonstrate that such correlations are generally true. Thus, in the present study, 10 aldehydes of varying degrees of allergenicity in man were evaluated in the LLNA and their EC3 values derived. Formaldehyde was regarded as the strongest allergen in man and also had the lowest EC3 value, 0.35% (equivalent to 0.93% formalin). In contrast, the extremely weak allergen vanillin and the non-sensitizer ethyl vanillin both had EC3 values of >50%. For the remaining 7 aldehydes, there was a close similarity between what is judged to be their rank order of allergenicity in humans and EC3 values derived from analysis of LLNA data. These results support further the utility of EC3 determinations in the LLNA as a measure of the relative potency of a contact allergen.
TL;DR: Positive behavioural effects have been described with several of the new anticonvulsants, particularly gabapentin, lamotrigine and oxcarbazepine; all of these drugs may have mood-levelling effects that could be of value in treating affective disorders.
Abstract: Of the 9 new anticonvulsants that have been marketed recently in the UK or US, a number appear to have either adverse or beneficial effects on behaviour. There is now a considerable database of information, in terms of the number of patients treated and/or the number of published reports, on vigabatrin, lamotrigine, gabapentin and topiramate. Oxcarbazepine has been available in some centres for several years and there is extensive experience with the drug in Scandinavia. It appears that the profile of adverse and beneficial effects is similar to that of carbamazepine.
TL;DR: The present results suggest that pigs from both treatment groups employed olfactory cues in social recognition, but that chronic exposure to ammonia did not interfere with this ability, and ammonia treatment seemingly affected social preferences.
TL;DR: It would appear that while it is possible to elicit robust IgE responses by gavage exposure of BALB/c strain mice to some protein allergens, such responses are generally weaker and less consistent than those provoked by i.p. administration, this method may provide one approach to the identification of potentialprotein allergens.
TL;DR: The method has been used to guide a mechanical hoe in winter wheat with an RMS positional error of 15.6 mm at a speed of 1.6 ms −1 , despite the presence of complex shadows cast by the tractor in the imaged area.
TL;DR: It is demonstrated that chemical allergens do stimulate consistent changes in IL‐1β mRNA expression in the proportion of donors who have a responsive phenotype, and that such responses are apparently selective for allergen using the relatively narrow range of materials assessed to date.
Abstract: The development of in vitro methods for the identification of skin sensitizers based upon analysis of Langerhans cell (LC) function has been constrained by the fact that these cells represent only a minority population in the skin that, once isolated, alter their phenotype spontaneously and rapidly. Methods have been developed recently that allow the expansion in culture using appropriate cytokine conditions of LC-like dendritic cells (DCs) from certain tissues, including human peripheral blood. It has been demonstrated that culture of human blood-derived LC-like cells with selected potent contact allergens such as 2,4-dinitrofluorobenzene (DNFB) stimulates selective phenotypic changes, including the up-regulation of interleukin 1 beta (IL-1 beta) mRNA expression, under conditions where skin irritants are without effect. However, in our own previous investigations, we have observed that there appear to be differences between blood donors with respect to the responsiveness of DCs to DNFB-induced changes in IL-1 beta expression, differences that could compromise the utility of this approach as a screening method for contact allergens. We have therefore investigated donor variability in DC responsiveness to a panel of known human contact allergens (DNFB; paraphenylene diamine, PPD; methyl- chloroisothiazolinone/methylisothiazolinone, CMIT), to the skin irritant benzalkonium chloride and to the mitogen phorbol myristate acetate (PMA). Dendritic cells derived from all donors expressed IL-1 beta mRNA constitutively. Treatment of DCs isolated from donors with a responder phenotype to DNFB with PPD or CMIT resulted also in up-regulation of IL-1 beta mRNA expression, although such changes were always comparatively modest, generally resulting in a twofold induction compared with vehicle-treated controls. Dendritic cells derived from donors with a non-responder phenotype to DNFB failed also to respond to these additional contact allergens under conditions where the mitogen PMA caused similar increases in IL-1 beta expression to those observed for allergen-responsive donors. Benzalkonium chloride failed to provoke changes in the expression of this cytokine in any donor examined, irrespective of their responder phenotype. The temporal stability of the responder/non-responder DC phenotype was confirmed, with stable phenotypes with respect to DNFB-induced changes in IL-1 beta mRNA expression observed over a period of some 18 months. Fifty per cent (6/12) of donors tested over this period displayed a responder phenotype. These data demonstrate that chemical allergens do stimulate consistent changes in IL-1 beta mRNA expression in the proportion of donors who have a responsive phenotype, and that such responses are apparently selective for allergen using the relatively narrow range of materials assessed to date. However, the modest response to very strong contact allergens, coupled with the difficulties of responder/non-responder phenotypes, means that in its present form this approach does not lend itself to the routine assessment of skin sensitizing activity.
TL;DR: In this article, the authors describe research which demonstrates that robotic harvesting of high-quality mushrooms, for the fresh market, is entirely feasible and demonstrate that a robotic harvester for high quality mushrooms can be constructed and used on a commercial farm.
TL;DR: The suitability of hexyl cinnamic aldehyde (HCA), a recommended positive control for skin sensitization testing, is examined as a calibrant for comparing the consistency of LLNA responses with time, and between laboratories, and thus for the routine assessment of assay reliability.
Abstract: The murine local lymph node assay (LLNA) for the prospective identification of contact allergens assesses skin sensitization potential as a function of proliferative activity induced in lymph nodes draining the site of topical exposure to test chemical. This method has been endorsed recently as a stand alone test for the identification of contact allergens. We have now examined the suitability of hexyl cinnamic aldehyde (HCA), a recommended positive control for skin sensitization testing, as a calibrant for comparing the consistency of LLNA responses with time, and between laboratories, and thus for the routine assessment of assay reliability. Standard LLNAs were performed with CBA strain mice in 3 independent laboratories over a period of 8 years. Dose-response curves were used to derive mathematically the EC3 value (the estimated concentration of chemical necessary to cause a stimulation index (SI) of 3 compared with proliferation induced by concurrent vehicle controls). In each laboratory, 6 separate experiments were conducted using a single concentration of HCA (25%). Very similar stimulation indices were achieved, with mean values of 9.0, 6.5 and 6.6 recorded. A total of 10 dose-response experiments were performed independently in the 3 laboratories and these revealed that there was very little inter-laboratory, or temporal, variation in EC3 values. These data confirm that HCA responses in the LLNA are very stable and demonstrate that HCA provides a suitable calibrant for determining assay sensitivity and performance.
TL;DR: In this article, the authors examine the physics of the fracture processes involved in breaking different food types, ranging widely from brittle fracture in dry cereal foods, nuts, and fresh vegetables, to the complex defibrillation and tensile failure in cooked meats.
Abstract: Most foods have solid-like properties and therefore must be size reduced in the mouth before swallowing. In this paper we will examine the physics of the fracture processes involved in breaking different food types. These range widely from brittle fracture in dry cereal foods, nuts, and fresh vegetables, to the complex defibrillation and tensile failure in cooked meats. We will examine how the differences in fracture and failure processes correlate with our perception of quality in various food types. This allows deduction of an overall model for the mastication process and how consumers may develop preferences for particular foods. The real stresses and strains exerted in the mouth are difficult to identify in local, spacial detail. Recent work is beginning to define how mouth motion controls the fracture process, and the impact of saliva on the mechanism of swallowing. Les mecanismes des fractures subies par differents aliments sont etudies: de l'emiettement des cereales jusqu'au phenomene complexe de desassemblage des fibres dans la viande. Un modele de mastication est deduit ainsi que les explications des preferences des consommateurs pour certains produits. Les differences dans les fractures peuvent etre correlees avec la perception de qualite.
TL;DR: In this paper, the moment transformations of the population balances taking into account the chemical and crystallization kinetics are integrated into a CFD solver to describe the generation and transportation of the crystal phase.
Abstract: To better understand the complicated phenomena in a precipitation process, computational fluid dynamics (CFD) is utilized to account for reactions, crystallization, mixing, and their interactions. The moment transformations of the population balances taking into account the chemical and crystallization kinetics are integrated into a CFD solver to describe the generation and transportation of the crystal phase. The current work applies this CFD tool to simulate the reactive precipitation process in a semibatch crystallizer, which is widely used in chemical and pharmaceutical industries. BaSO4 precipitation is employed as an example system. The influence of hydrodynamics in the stirred tank, as characterized by the impeller speed and feed location, on the distribution of supersaturation and the subsequent crystal size distribution is investigated. The numerical predictions are validated with measurements and can be used as an aid in the optimization of semibatch precipitator design.
TL;DR: The aim is to provide evidence to support or refute the hypothesis that cross‐resistance between antibiotics and biocides can occur.
Abstract: Aims: To provide evidence to support or refute the hypothesis that cross-resistance between antibiotics and biocides can occur.
Methods and Results: Fifty-five strains of Pseudomonas aeruginosa were tested for their resistance to anti-pseudomonal antibacterials. Twenty clinical, 19 industrial and 16 culture collection isolates were used. The MIC was found for the antibiotics amikacin, ceftazidime, ciprofloxacin, gentamycin, ticarcillin, tobramycin, imipenem and polymyxin B. The MIC was also found for the biocides benzalkonium chloride and chlorhexidine. The analysis of the data was based on the production of a normal distribution of the log (MIC) plots for each antimicrobial. Strains were then labelled as resistant, intermediate or sensitive based on the mean and standard deviation of the distributions.
Conclusions: In general the clinical isolates were the most recalcitrant organisms, with the industrial isolates being the most sensitive.
Significance and Impact of the Study: The work shows that antibiotic/biocide correlations do occur, especially with clinical strains. That such correlations were not found with industrial isolates suggests that the clinical environment is responsible for the correlation. We could infer that it is the selective pressure of antibiotic usage that differentiates the clinical environment from the industrial.