Pub Date : 2010-06-01DOI: 10.1093/BIOHORIZONS/HZQ016
Matthew Smith
Vitamin D is a fundamentally important hormone involved in calcium absorption, bone mineralization and parathyroid hormone production. Vitamin D deficiency may result in a myriad of diseases, such as osteomalacia, rickets and has more recently been identified as a risk factor for diabetes. Accurate determination of serum vitamin D levels is, therefore, paramount when assessing an individual for related pathologies against an appropriate reference range for interpretation. The purpose of this study was to assess vitamin D status between ‘healthy’ Caucasian and ‘healthy’ Asian populations of Peterborough, taking into account seasonal serum vitamin D variation. In addition, we evaluated whether a reference range for serum vitamin D of the local population should be race and/or seasonal specific. Using a Chromsystems high-pressure liquid chromatography vitamin D2/D3 methodology upon Agilent 1100 hardware, serum vitamin D status was assessed in 200 subjects of varying age, gender and ethnicity using summer (n = 106) and winter (n = 94) cohorts. Serum vitamin D3 levels were significantly lower (up to 70%; P ? 0.0001) in both men and women of the Asian population in comparison to the Caucasian population during both the summer and winter periods. Vitamin D3 levels of the Caucasian cohort displayed significant variation between summer and winter (P?0.0001), while the overall Asian population displayed no significant seasonal variation in vitamin D status. The reference range produced by the Caucasian cohorts (8.2–53.7 µg/l) complements published studies, while the Asian cohort displayed significantly lower limits (3.6–26.7 µg/l). Currently, no genetic predisposition to lower vitamin D status in Asians compared with Caucasians has been established. Therefore, the Caucasian range was implemented for all ethnicities, as this conforms to the national consensus of deficiency within the UK. This reference range indicates that 34% of the ‘healthy’ Asian community are vitamin D deficient compared with 2% of Caucasians. Further research is required to increase vitamin D deficiency awareness in Asian communities and highlight the potential role of supplementation.
{"title":"Seasonal, ethnic and gender variations in serum vitamin D3 levels in the local population of Peterborough","authors":"Matthew Smith","doi":"10.1093/BIOHORIZONS/HZQ016","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZQ016","url":null,"abstract":"Vitamin D is a fundamentally important hormone involved in calcium absorption, bone mineralization and parathyroid hormone production. Vitamin D deficiency may result in a myriad of diseases, such as osteomalacia, rickets and has more recently been identified as a risk factor for diabetes. Accurate determination of serum vitamin D levels is, therefore, paramount when assessing an individual for related pathologies against an appropriate reference range for interpretation. The purpose of this study was to assess vitamin D status between ‘healthy’ Caucasian and ‘healthy’ Asian populations of Peterborough, taking into account seasonal serum vitamin D variation. In addition, we evaluated whether a reference range for serum vitamin D of the local population should be race and/or seasonal specific. Using a Chromsystems high-pressure liquid chromatography vitamin D2/D3 methodology upon Agilent 1100 hardware, serum vitamin D status was assessed in 200 subjects of varying age, gender and ethnicity using summer (n = 106) and winter (n = 94) cohorts. Serum vitamin D3 levels were significantly lower (up to 70%; P ? 0.0001) in both men and women of the Asian population in comparison to the Caucasian population during both the summer and winter periods. Vitamin D3 levels of the Caucasian cohort displayed significant variation between summer and winter (P?0.0001), while the overall Asian population displayed no significant seasonal variation in vitamin D status. The reference range produced by the Caucasian cohorts (8.2–53.7 µg/l) complements published studies, while the Asian cohort displayed significantly lower limits (3.6–26.7 µg/l). Currently, no genetic predisposition to lower vitamin D status in Asians compared with Caucasians has been established. Therefore, the Caucasian range was implemented for all ethnicities, as this conforms to the national consensus of deficiency within the UK. This reference range indicates that 34% of the ‘healthy’ Asian community are vitamin D deficient compared with 2% of Caucasians. Further research is required to increase vitamin D deficiency awareness in Asian communities and highlight the potential role of supplementation.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"3 1","pages":"124-131"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZQ016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-01DOI: 10.1093/BIOHORIZONS/HZQ013
Joseph Hancock
The Earth's ecosystems supply human society with a stream of services, the sustained delivery of which remains crucial to our health, economic prosperity and personal and national security. Ecosystem services provide these benefits across a range of geographical scales (local, regional and global) and to many different groups (individuals, businesses and governments). In spite of this, ecosystem services are continually underrepresented and undervalued within decision-making situations. As a result, the capacity of ecosystems to supply a number of services—including the supply of food and freshwater, the regulation of disease and protection from natural hazards—has been degraded worldwide, with serious consequences for human wellbeing. The actions of man are unwittingly depleting the planet's natural capital and putting such strain on the environment that the capacity of Earth's ecosystems to support future generations can no longer be taken for granted. To address this we need a new approach to the way that decisions are made at the interface of the environment and society—one where the benefits and services provided by ecosystems are understood, evaluated and appropriately represented within the decision-making arena. By drawing attention to the failures and consequences of past and present attitudes in decision-making and resource management, this article frames a way forward to help avoid such problems in the future. Specifically, it outlines the rationale behind the need for an ecosystem service approach to decision-making and highlights some of the research needs that will help in selecting policies that sustain ecosystem services.
{"title":"The case for an ecosystem service approach to decision-making: an overview","authors":"Joseph Hancock","doi":"10.1093/BIOHORIZONS/HZQ013","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZQ013","url":null,"abstract":"The Earth's ecosystems supply human society with a stream of services, the sustained delivery of which remains crucial to our health, economic prosperity and personal and national security. Ecosystem services provide these benefits across a range of geographical scales (local, regional and global) and to many different groups (individuals, businesses and governments). In spite of this, ecosystem services are continually underrepresented and undervalued within decision-making situations. As a result, the capacity of ecosystems to supply a number of services—including the supply of food and freshwater, the regulation of disease and protection from natural hazards—has been degraded worldwide, with serious consequences for human wellbeing. The actions of man are unwittingly depleting the planet's natural capital and putting such strain on the environment that the capacity of Earth's ecosystems to support future generations can no longer be taken for granted. To address this we need a new approach to the way that decisions are made at the interface of the environment and society—one where the benefits and services provided by ecosystems are understood, evaluated and appropriately represented within the decision-making arena. By drawing attention to the failures and consequences of past and present attitudes in decision-making and resource management, this article frames a way forward to help avoid such problems in the future. Specifically, it outlines the rationale behind the need for an ecosystem service approach to decision-making and highlights some of the research needs that will help in selecting policies that sustain ecosystem services.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"3 1","pages":"188-196"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZQ013","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-01DOI: 10.1093/BIOHORIZONS/HZQ018
K. Hayer
Transformation is an important tool in modern genetic engineering and artificial methods exist to induce transformation in bacteria. Ultrasound offers the potential advantage of being versatile and less dependent on cell types than traditional methods like electroporation. This study investigated the effect of low-frequency ultrasound exposure on the ability of Escherichia coli (E. coli) to undergo transformation. E. coli HB101 in the presence of pBR322 plasmid was exposed to ultrasound frequencies of 48 kHz for 10-1200 s and monitored over a 24 and 48 h period. The most effective transformation efficiency (148.72 transformants μg −1 of DNA) was observed at 10 s exposure to ultrasound and after 24 h incubation. The ultrasound method was compared with the calcium chloride (CaCl 2 ) method of inducing artificial competence. There was a significant difference between 0.05 mM CaCl 2 induced transformation (4.70 transformants μg −1 of DNA) and 10 s exposure to ultrasound transformation (148.72 transformants μg −1 of DNA) after 24 h incubation. This study highlights the potential of ultrasound as a realistic alternative to induce competence for the genetic manipulation of bacteria.
{"title":"The effect of ultrasound exposure on the transformation efficiency of Escherichia coli HB101","authors":"K. Hayer","doi":"10.1093/BIOHORIZONS/HZQ018","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZQ018","url":null,"abstract":"Transformation is an important tool in modern genetic engineering and artificial methods exist to induce transformation in bacteria. Ultrasound offers the potential advantage of being versatile and less dependent on cell types than traditional methods like electroporation. This study investigated the effect of low-frequency ultrasound exposure on the ability of Escherichia coli (E. coli) to undergo transformation. E. coli HB101 in the presence of pBR322 plasmid was exposed to ultrasound frequencies of 48 kHz for 10-1200 s and monitored over a 24 and 48 h period. The most effective transformation efficiency (148.72 transformants μg −1 of DNA) was observed at 10 s exposure to ultrasound and after 24 h incubation. The ultrasound method was compared with the calcium chloride (CaCl 2 ) method of inducing artificial competence. There was a significant difference between 0.05 mM CaCl 2 induced transformation (4.70 transformants μg −1 of DNA) and 10 s exposure to ultrasound transformation (148.72 transformants μg −1 of DNA) after 24 h incubation. This study highlights the potential of ultrasound as a realistic alternative to induce competence for the genetic manipulation of bacteria.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"3 1","pages":"141-147"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZQ018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764486","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-06-01DOI: 10.1093/BIOHORIZONS/HZQ020
Jacqueline Tawse
Recent years have seen an increase in public concern for farm animal welfare in the UK. However, sales of higher welfare meat and other animal-based food products are typically lower than their standard counterparts. The aim of this study was to determine both the prevalence of concern for farm animal welfare in a population, as well as the reasons for higher concern in some consumers as compared with others. In addition, the study focused on consumer attitudes towards pigs (Sus scrofa scrofa), and concern for their welfare, in particular, in order to identify areas which, if addressed, may help to increase consumer concern for pig welfare on farms, as well as increase consumer demand for higher welfare pork products. A questionnaire was designed with this in mind and disseminated to undergraduate students at the University of Chester. Concern for farm animal welfare, concern for the welfare of pigs on farms and reported willingness to pay extra for higher welfare pork products were all found to be influenced by consumer attitudes towards pigs, participant programme of study, awareness of pork production methods and previous exposure to a conventional pig farm. In addition, the results of the study indicate that a high level of ignorance regarding pork production methods is prevalent amongst UK consumers. In order to increase concern for pig welfare on farms, and thereby increase demand for higher welfare pork products, it was suggested that campaigns should aim to make clear the production methods used in conventional pork production systems in the UK.
{"title":"Consumer attitudes towards farm animals and their welfare: a pig production case study","authors":"Jacqueline Tawse","doi":"10.1093/BIOHORIZONS/HZQ020","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZQ020","url":null,"abstract":"Recent years have seen an increase in public concern for farm animal welfare in the UK. However, sales of higher welfare meat and other animal-based food products are typically lower than their standard counterparts. The aim of this study was to determine both the prevalence of concern for farm animal welfare in a population, as well as the reasons for higher concern in some consumers as compared with others. In addition, the study focused on consumer attitudes towards pigs (Sus scrofa scrofa), and concern for their welfare, in particular, in order to identify areas which, if addressed, may help to increase consumer concern for pig welfare on farms, as well as increase consumer demand for higher welfare pork products. A questionnaire was designed with this in mind and disseminated to undergraduate students at the University of Chester. Concern for farm animal welfare, concern for the welfare of pigs on farms and reported willingness to pay extra for higher welfare pork products were all found to be influenced by consumer attitudes towards pigs, participant programme of study, awareness of pork production methods and previous exposure to a conventional pig farm. In addition, the results of the study indicate that a high level of ignorance regarding pork production methods is prevalent amongst UK consumers. In order to increase concern for pig welfare on farms, and thereby increase demand for higher welfare pork products, it was suggested that campaigns should aim to make clear the production methods used in conventional pork production systems in the UK.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"3 1","pages":"156-165"},"PeriodicalIF":0.0,"publicationDate":"2010-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZQ020","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-03-01DOI: 10.1093/BIOHORIZONS/HZQ009
Ryan Bishop
Fluorescence in situ hybridization (FISH) is a powerful technique used in the detection of chromosomal abnormalities. The high sensi- tivity and specificity of FISH and the speed with which the assays can be performed have made FISH a pivotal cytogenetic technique that has provided significant advances in both the research and diagnosis of haematological malignancies and solid tumours. From a medical perspective, FISH can be applied to detect genetic abnormalities such as characteristic gene fusions, aneuploidy, loss of a chromosomal region or a whole chromosome or to monitor the progression of an aberration serving as a technique that can help in both the diagnosis of a genetic disease or suggesting prognostic outcomes. FISH can also be applied to such research applications as gene mapping or the identification of novel oncogenes or genetic aberrations that contribute towards various cancers. FISH is based on DNA probes annealing to specific target sequence of sample DNA. Attached to the probes are fluorescent reporter molecules which under fluorescence microscopy confirm the presence or absence of a particular genetic aberration when viewed under fluorescence microscopy. The tech- nique has recently evolved to allow screening of the whole genome simultaneously through multicolour whole-chromosome probe techniques such as multiplex FISH or spectral karyotyping, or through an array-based method using comparative genomic hybridization. This simple, yet effective, technique has revolutionized cytogenetics and has become well established in its potential as a diagnostic and discovery tool in the fight against cancer.
{"title":"Applications of fluorescence in situ hybridization (FISH) in detecting genetic aberrations of medical significance","authors":"Ryan Bishop","doi":"10.1093/BIOHORIZONS/HZQ009","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZQ009","url":null,"abstract":"Fluorescence in situ hybridization (FISH) is a powerful technique used in the detection of chromosomal abnormalities. The high sensi- tivity and specificity of FISH and the speed with which the assays can be performed have made FISH a pivotal cytogenetic technique that has provided significant advances in both the research and diagnosis of haematological malignancies and solid tumours. From a medical perspective, FISH can be applied to detect genetic abnormalities such as characteristic gene fusions, aneuploidy, loss of a chromosomal region or a whole chromosome or to monitor the progression of an aberration serving as a technique that can help in both the diagnosis of a genetic disease or suggesting prognostic outcomes. FISH can also be applied to such research applications as gene mapping or the identification of novel oncogenes or genetic aberrations that contribute towards various cancers. FISH is based on DNA probes annealing to specific target sequence of sample DNA. Attached to the probes are fluorescent reporter molecules which under fluorescence microscopy confirm the presence or absence of a particular genetic aberration when viewed under fluorescence microscopy. The tech- nique has recently evolved to allow screening of the whole genome simultaneously through multicolour whole-chromosome probe techniques such as multiplex FISH or spectral karyotyping, or through an array-based method using comparative genomic hybridization. This simple, yet effective, technique has revolutionized cytogenetics and has become well established in its potential as a diagnostic and discovery tool in the fight against cancer.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"3 1","pages":"85-95"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZQ009","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-03-01DOI: 10.1093/BIOHORIZONS/HZQ005
J. Sleigh
Parasitic nematodes pose a significant threat to the health and economic welfare of communities worldwide, both directly through human disease and indirectly through infection of livestock and crop. At present, anthelmintic drugs such as the nicotinic agonists, which target nematode nicotinic acetylcholine receptors (nAChRs), offer a facile and cost-effective method of controlling both human and animal infection. Unfortunately, the continued heavy reliance on such compounds has led to the inevitable emergence of resistance in many different Nematoda species, thus making the subject of nematode nicotinic receptors of great importance. Using various levamisole-resistant, nAChR subunit mutants of the soil-dwelling nematode Caenorhabditis elegans (viz. unc-29, unc-38 and unc-63) and well-established resistance-monitoring assays, the responses of the different strains to the nicotinic agonists levamisole, morantel, oxantel and pyrantel have begun to be characterized. Wild-type adult C. elegans are relatively unaffected by 1 mM oxantel, contrasting with a developmental retardation of larvae. Also, unc-38 mutants appear to be less refractory to the anthelmintics than the unc-29 and unc-63 animals. In preparation for the use of C. elegans as an ectopic transformation system for parasitic receptor DNA, preliminary biolistic transformation experiments were performed using microparticle bombardment. It was found that transformation of unc-38 animals with myo-3::gfp construct has no significant effect on their ability to thrash in suspension. The mutant characterization data may possibly reflect differential expression of nAChRs at various stages of development. The transformation data suggest that microparticle bombardment has little or no effect on C. elegans, which is essential for future transgenic experiments. In summary, important baseline data on C. elegans nicotinic receptors have been generated and a fundamental transgenic control line in unc-38;myo3::gfp has been established. This will allow for exciting rescue experiments using parasitic nematode nAChR DNA.
{"title":"Functional analysis of nematode nicotinic receptors","authors":"J. Sleigh","doi":"10.1093/BIOHORIZONS/HZQ005","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZQ005","url":null,"abstract":"Parasitic nematodes pose a significant threat to the health and economic welfare of communities worldwide, both directly through human disease and indirectly through infection of livestock and crop. At present, anthelmintic drugs such as the nicotinic agonists, which target nematode nicotinic acetylcholine receptors (nAChRs), offer a facile and cost-effective method of controlling both human and animal infection. Unfortunately, the continued heavy reliance on such compounds has led to the inevitable emergence of resistance in many different Nematoda species, thus making the subject of nematode nicotinic receptors of great importance. Using various levamisole-resistant, nAChR subunit mutants of the soil-dwelling nematode Caenorhabditis elegans (viz. unc-29, unc-38 and unc-63) and well-established resistance-monitoring assays, the responses of the different strains to the nicotinic agonists levamisole, morantel, oxantel and pyrantel have begun to be characterized. Wild-type adult C. elegans are relatively unaffected by 1 mM oxantel, contrasting with a developmental retardation of larvae. Also, unc-38 mutants appear to be less refractory to the anthelmintics than the unc-29 and unc-63 animals. In preparation for the use of C. elegans as an ectopic transformation system for parasitic receptor DNA, preliminary biolistic transformation experiments were performed using microparticle bombardment. It was found that transformation of unc-38 animals with myo-3::gfp construct has no significant effect on their ability to thrash in suspension. The mutant characterization data may possibly reflect differential expression of nAChRs at various stages of development. The transformation data suggest that microparticle bombardment has little or no effect on C. elegans, which is essential for future transgenic experiments. In summary, important baseline data on C. elegans nicotinic receptors have been generated and a fundamental transgenic control line in unc-38;myo3::gfp has been established. This will allow for exciting rescue experiments using parasitic nematode nAChR DNA.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"3 1","pages":"29-39"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZQ005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-03-01DOI: 10.1093/BIOHORIZONS/HZQ008
S. Nattrass
Methane is an important greenhouse gas, contributing 22% to the increased radiative forcing over 150 years, and emissions from wetlands are key to its global dynamics. A general model of methane dynamics is presented that emphasizes the impact of external climate factors on methane production and oxidation. The model consists of two uncoupled bacterial populations, each following a logistic growth pattern, and a third differential equation, dependent on these two populations, that represents the concentration of stored methane in wetland soils. This is related to methane emissions into the atmosphere. Several simplified models are also presented to demonstrate the development of the model from the basic processes occurring in the soil. Analysis of the model shows a stable equilibrium point for the methane concentration. This equilibrium is subject to short-term forcing by climate, specifically changes in temperature and water table depth. Parameters for this model are then fitted to real data taken from a wetland site in Teesdale, and this forcing is shown to account for much of the observed variation in methane emissions. An attempt to extend this model to longer time scales is made, by considering the average climate. This extension is shown to be unsuccessful through considering Taylor’s theorem and its implications for the model. Finally, a simplistic approximation to climate change is made, and the consequences of these changes on methane emissions predicted by the model are presented. These consequences are found to include negative feedback, where the change in climate eventually results in lower emissions of methane.
{"title":"A study of the dynamics behind methane emissions from northern wetlands","authors":"S. Nattrass","doi":"10.1093/BIOHORIZONS/HZQ008","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZQ008","url":null,"abstract":"Methane is an important greenhouse gas, contributing 22% to the increased radiative forcing over 150 years, and emissions from wetlands are key to its global dynamics. A general model of methane dynamics is presented that emphasizes the impact of external climate factors on methane production and oxidation. The model consists of two uncoupled bacterial populations, each following a logistic growth pattern, and a third differential equation, dependent on these two populations, that represents the concentration of stored methane in wetland soils. This is related to methane emissions into the atmosphere. Several simplified models are also presented to demonstrate the development of the model from the basic processes occurring in the soil. Analysis of the model shows a stable equilibrium point for the methane concentration. This equilibrium is subject to short-term forcing by climate, specifically changes in temperature and water table depth. Parameters for this model are then fitted to real data taken from a wetland site in Teesdale, and this forcing is shown to account for much of the observed variation in methane emissions. An attempt to extend this model to longer time scales is made, by considering the average climate. This extension is shown to be unsuccessful through considering Taylor’s theorem and its implications for the model. Finally, a simplistic approximation to climate change is made, and the consequences of these changes on methane emissions predicted by the model are presented. These consequences are found to include negative feedback, where the change in climate eventually results in lower emissions of methane.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"3 1","pages":"57-65"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZQ008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-03-01DOI: 10.1093/BIOHORIZONS/HZQ002
Grant English
Macrophage ‘foam cells’ are the hallmark of early, and developing, atherosclerotic lesions. Generation of 27-oxygenated derivatives of cholesterol, one of the most abundant oxysterols in human atheroma, via mitochondrial sterol 27-hydroxylase (CYP27A1), achieves ligand-activation of liver X nuclear receptors (LXR), which marshal cholesterol homeostatic mechanisms leading to cholesterol efflux and nascent high-density lipoprotein generation. The rate-limiting step controlling activity of CYP27A1 is supply of cholesterol from the outer to the inner (cholesterol-poor) mitochondrial membrane, and can be facilitated by steroidogenic acute regulatory protein (StAR). However, LXR activation also exerts indirect control (transrepression) over gene expression of a range of inflammatory mediators, via interference with nuclear factor-kappa B transcription factors, integrating metabolic and inflammatory signalling. Here, we considered the impact of increased cholesterol delivery to CYP27A1 on the expression of inflammatory mediators: Toll-like receptor 3 (Tlr3), Toll-like receptor 6 (Tlr6) and lymphotoxin alpha (Lta). Murine RAW 264.7 macrophages stably transfected with pCMV.5 (empty vector control) and pCMV.5_Stard1 (StAR over-expressing) were challenged for 24 h, in the presence or absence of dibutyryl cAMP (0.3 mM), lipopolysaccharide (LPS; 0.1 mg/ml), LXR agonist (T0901317; 10 mM) and combinations thereof. Following isolation of RNA and cDNA synthesis, qualitative polymerase chain reaction (PCR) was used to determine the presence and expression of StAR (355 bp) and housekeeping gene, glyceraldehyde 3-phosphate dehydrogenase (GAPDH; 410 bp), in each cell line. Levels of Stard1, Tlr3, Tlr6 and Lta mRNA were determined by quantitative PCR and expressed as a ratio to Gapdh. Over-expression of StAR significantly altered expression of genes implicated in the innate immune response, increasing Tlr3, Tlr6 and Lta expression under basal conditions, or following the addition of cAMP to increase StAR activity. Addition of LPS decreased intracellular levels of Stard1 mRNA; preliminary evidence of Tlr6 transrepression was also noted in StAR over-expressing cells following this inflammatory challenge. In contrast, induction of Tlr3 was noted in control following addition of LXR agonist, T0901317, suggesting Tlr3 may be a direct LXR target; Lta expression was also enhanced in StAR over-expressing cells in the presence of this agonist. These results should be considered carefully when developing StAR as a possible therapeutic strategy for human metabolic disease.
{"title":"Mitochondrial cholesterol trafficking: impact on inflammatory mediators","authors":"Grant English","doi":"10.1093/BIOHORIZONS/HZQ002","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZQ002","url":null,"abstract":"Macrophage ‘foam cells’ are the hallmark of early, and developing, atherosclerotic lesions. Generation of 27-oxygenated derivatives of cholesterol, one of the most abundant oxysterols in human atheroma, via mitochondrial sterol 27-hydroxylase (CYP27A1), achieves ligand-activation of liver X nuclear receptors (LXR), which marshal cholesterol homeostatic mechanisms leading to cholesterol efflux and nascent high-density lipoprotein generation. The rate-limiting step controlling activity of CYP27A1 is supply of cholesterol from the outer to the inner (cholesterol-poor) mitochondrial membrane, and can be facilitated by steroidogenic acute regulatory protein (StAR). However, LXR activation also exerts indirect control (transrepression) over gene expression of a range of inflammatory mediators, via interference with nuclear factor-kappa B transcription factors, integrating metabolic and inflammatory signalling. Here, we considered the impact of increased cholesterol delivery to CYP27A1 on the expression of inflammatory mediators: Toll-like receptor 3 (Tlr3), Toll-like receptor 6 (Tlr6) and lymphotoxin alpha (Lta). Murine RAW 264.7 macrophages stably transfected with pCMV.5 (empty vector control) and pCMV.5_Stard1 (StAR over-expressing) were challenged for 24 h, in the presence or absence of dibutyryl cAMP (0.3 mM), lipopolysaccharide (LPS; 0.1 mg/ml), LXR agonist (T0901317; 10 mM) and combinations thereof. Following isolation of RNA and cDNA synthesis, qualitative polymerase chain reaction (PCR) was used to determine the presence and expression of StAR (355 bp) and housekeeping gene, glyceraldehyde 3-phosphate dehydrogenase (GAPDH; 410 bp), in each cell line. Levels of Stard1, Tlr3, Tlr6 and Lta mRNA were determined by quantitative PCR and expressed as a ratio to Gapdh. Over-expression of StAR significantly altered expression of genes implicated in the innate immune response, increasing Tlr3, Tlr6 and Lta expression under basal conditions, or following the addition of cAMP to increase StAR activity. Addition of LPS decreased intracellular levels of Stard1 mRNA; preliminary evidence of Tlr6 transrepression was also noted in StAR over-expressing cells following this inflammatory challenge. In contrast, induction of Tlr3 was noted in control following addition of LXR agonist, T0901317, suggesting Tlr3 may be a direct LXR target; Lta expression was also enhanced in StAR over-expressing cells in the presence of this agonist. These results should be considered carefully when developing StAR as a possible therapeutic strategy for human metabolic disease.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"3 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZQ002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-03-01DOI: 10.1093/BIOHORIZONS/HZQ003
R. Hider
E-learning encourages positive student attitudes and has been shown to have a positive effect on the process of learning. Undergraduate nursing students at the University of Manchester are not provided with any practical haematology experience in their first year, and receive only a single lecture specific to white blood cell structure and function. The aim of the project was to produce an interactive e-learning resource to increase student knowledge of the five major types of white blood cell and the differential white cell count. The production of the resource followed the ADDIE instructional design model with phases of Analysis, Design, Development, Implementation and Evaluation. A scenario-based approach was used in the design phase to illustrate the importance of the different white blood cells in a clinical setting. The development of the resource in Opus Professional allowed interactive features to be incorporated. The null hypothesis stated that the resource would not cause a significant improvement in student knowledge of this area. Assessment questions testing student knowledge were completed by randomly selected participants from the target audience assigned to two independent groups. The pre-resource group (n 1⁄4 29) completed the questions without use of the e-learning resource or any alternative mode of teaching, whereas the post-resource group (n 1⁄4 25) completed the questions after use of the resource. Scores from the preand post-resource groups were then compared in order to assess the effectiveness and functionality of the resource. Overall, there was a significant improvement in participant knowledge after use of the e-learning resource (Mann–Whitney U-test, U 1⁄4 154.500, p 1⁄4 0.000). This allowed the null hypothesis to be rejected and showed that the learning outcomes had been achieved. 92% of participants found the resource enjoyable while 84% thought that the resource was effective in improving their knowledge of this area. This confirms findings from other research that e-learning has positive effects on learning outcomes and that students enjoy this learning methodology.
{"title":"Differential white cell counts: an e-learning resource","authors":"R. Hider","doi":"10.1093/BIOHORIZONS/HZQ003","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZQ003","url":null,"abstract":"E-learning encourages positive student attitudes and has been shown to have a positive effect on the process of learning. Undergraduate nursing students at the University of Manchester are not provided with any practical haematology experience in their first year, and receive only a single lecture specific to white blood cell structure and function. The aim of the project was to produce an interactive e-learning resource to increase student knowledge of the five major types of white blood cell and the differential white cell count. The production of the resource followed the ADDIE instructional design model with phases of Analysis, Design, Development, Implementation and Evaluation. A scenario-based approach was used in the design phase to illustrate the importance of the different white blood cells in a clinical setting. The development of the resource in Opus Professional allowed interactive features to be incorporated. The null hypothesis stated that the resource would not cause a significant improvement in student knowledge of this area. Assessment questions testing student knowledge were completed by randomly selected participants from the target audience assigned to two independent groups. The pre-resource group (n 1⁄4 29) completed the questions without use of the e-learning resource or any alternative mode of teaching, whereas the post-resource group (n 1⁄4 25) completed the questions after use of the resource. Scores from the preand post-resource groups were then compared in order to assess the effectiveness and functionality of the resource. Overall, there was a significant improvement in participant knowledge after use of the e-learning resource (Mann–Whitney U-test, U 1⁄4 154.500, p 1⁄4 0.000). This allowed the null hypothesis to be rejected and showed that the learning outcomes had been achieved. 92% of participants found the resource enjoyable while 84% thought that the resource was effective in improving their knowledge of this area. This confirms findings from other research that e-learning has positive effects on learning outcomes and that students enjoy this learning methodology.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"3 1","pages":"10-20"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZQ003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-03-01DOI: 10.1093/BIOHORIZONS/HZQ004
F. M. Docherty
Fibroblast growth factor-four (FGF4) signalling is essential for embryonic stem (ES) cells to become competent to undergo differentiation and enter lineage commitment pathways. The signalling pathway whereby this occurs is as yet not fully characterized. In this study, high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis was used in conjunction with phosphopeptide enrichment using TiO2 affinity chromatography to detect peptides phosphorylated in response to FGF stimulation of mouse ES cells. Many phosphorylation events were observed in FGF-treated ES cells and some phosphopeptides were unambiguously identified that associate with four different proteins: Lig1, Eif3b, 6430527G18Rik and Sin3a. We propose a novel pathway in which FGF signalling enables differentiation of ES cells via activation of Sin3a, a transcription repressor, which regulates expression of pluripotency genes.
{"title":"The identification of FGF-dependent phosphorylation events in embryonic stem cells using mass spectrometry","authors":"F. M. Docherty","doi":"10.1093/BIOHORIZONS/HZQ004","DOIUrl":"https://doi.org/10.1093/BIOHORIZONS/HZQ004","url":null,"abstract":"Fibroblast growth factor-four (FGF4) signalling is essential for embryonic stem (ES) cells to become competent to undergo differentiation and enter lineage commitment pathways. The signalling pathway whereby this occurs is as yet not fully characterized. In this study, high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis was used in conjunction with phosphopeptide enrichment using TiO2 affinity chromatography to detect peptides phosphorylated in response to FGF stimulation of mouse ES cells. Many phosphorylation events were observed in FGF-treated ES cells and some phosphopeptides were unambiguously identified that associate with four different proteins: Lig1, Eif3b, 6430527G18Rik and Sin3a. We propose a novel pathway in which FGF signalling enables differentiation of ES cells via activation of Sin3a, a transcription repressor, which regulates expression of pluripotency genes.","PeriodicalId":52095,"journal":{"name":"Bioscience Horizons","volume":"3 1","pages":"21-28"},"PeriodicalIF":0.0,"publicationDate":"2010-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/BIOHORIZONS/HZQ004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60764661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：