Carlo Leifert | Newcastle University (original) (raw)

Papers by Carlo Leifert

NJAS - Wageningen Journal of Life Sciences, 2011

In the last decade the main goals of organic dairying have been to attain acceptable levels of mi... more In the last decade the main goals of organic dairying have been to attain acceptable levels of milk production, increase opportunities for animals to perform species own behaviour, resulting in improved animal welfare and animal health, and minimize the use of therapeutic interventions, including the reduction of the (preventive) use of antibiotics. Maintaining animal health without the use of therapeutic interventions is a major challenge for organic dairy farmers. In particular, udder health remains a major problem in both conventional and organic farming. In the QualityLowInputFood (QLIF) project udder health status and management were assessed in different production systems and European regions. These studies suggest that good udder health can be maintained in organic or low-input farming management systems. Novel strategies to control mastitis were evaluated and the potential of using internal teat sealers for the control of environment-associated pathogens was shown. Also oral application of a herd profile based single homeopathic remedy combined with homeopathic silica had a significant effect on cows with a relative low somatic cell count before drying-off. Suckling systems in calf rearing, as an integrated management approach, did not result in better udder health. None of the studies presented identified new variables affecting udder health. QLIF studies also demonstrated the importance of comparing udder health parameters in contrasting organic, low input and conventional production systems, since clear differences in antibiotic use against mastitis could be identified not only between organic and conventional systems, but also among dairy systems used in different EU-countries. Although alternative treatments used in organic systems could not be shown to be fully effective, results suggest that the use of individual or combined alternative strategies to improve udder health on organic or low-input farms warrants further investigation. Based on the results obtained it is recommended that future research should focus on identifying the reasons for variability in udder health between organic farms that use different management protocols to identify 'best current practice' when carrying out this research.

Milicia species (M. excelsa and M. regia, Moraceae, the irokos) are among the most useful indigen... more Milicia species (M. excelsa and M. regia, Moraceae, the irokos) are among the most useful indigenous rain forest tree species in Africa. They are not grown in plantations but extracted from the natural forest at an unsustainable rate. The major constraint on cultivation and afforestation is the gall-forming insect Phytolyma lata, which destroys seedlings through gall formation, causing dieback of the shoot. Genetic diversity studies should aid the design of conservation and resistance-breeding strategies. This study, therefore, aimed to investigate the genetic variability in Milicia from three West African countries and the power of bulk-family DNA in partitioning ofˆgenetic diversity. Genetic variation within and between 5 natural populations of Milicia from Ghana, Cote d'Ivoire and Sierra Leone was investigated using random amplified polymorphic DNA (RAPD) and non-coding chloro-plast DNA sequencing. RAPD analysis of 41 DNA samples with 8 primers produced a total of 74 bands with 40 bands (54.1%) being polymorphic. Dendrogram analysis produced 2 major clusters separating dry and moist / wet ecotypes. Sub-clustering further separated accessions by forest type and / or geographic region. A greater proportion of the total genetic variability was attributed to variation between populations (62.2%) than within Leu populations (37.8%). Sequencing of chloroplast tRNA intron (cptrnL) and intergenic spacer (cpIGS) between Phe cptrnL and tRNA (trnF) did not show any variation. The RAPD analysis suggests that trees from wet / moist sites are mostly M. regia, while those from dry sites are mostly M. excelsa. Sequencing results, however, suggest that the two species are closely related. These results are discussed with reference to conservation strategies.

PROTEOMICS, 2007

Abbreviations: ANOVA, analysis of variance; Hsp, heat shock protein; PCA, principal component ana... more Abbreviations: ANOVA, analysis of variance; Hsp, heat shock protein; PCA, principal component analysis

Journal of Agricultural and Food Chemistry, 2012

In the European integrated research project SAFEFOODS, one of the aims was to further establish t... more In the European integrated research project SAFEFOODS, one of the aims was to further establish the potential of transcriptomics for the assessment of differences between plant varieties grown under different environmental conditions. Making use of the knowledge of cellular processes and interactions is one of the ways to obtain a better understanding of the differences found with transcriptomics. For the present study the potato genotype Santé was grown under both organic and conventional fertilizer, and each combined with either organic or conventional crop protection, giving four different treatments. Samples were derived from the European project QualityLowInputFood (QLIF). Microarray data were analyzed using different statistical tools (multivariate, principal components analysis (PCA); univariate, analysis of variance (ANOVA)) and with pathway analysis (hypergeometric distribution (HGD) and gene set enrichment analysis (GSEA)). Several biological processes were implicated as a result of the different treatments of the plants. Most obvious were the lipoxygenase pathway, with higher expression in organic fertilizer and lower expression in organic crop protection; the starch synthase pathway, with higher expression in both organic crop protection and fertilizer; and the biotic stress pathway, with higher expression in organic fertilizer. This study confirmed that gene expression profiling in combination with pathway analysis can identify and characterize differences between plants grown under different environmental conditions.

Managing Risks of Nitrates to Humans and the Environment, 1999

... Hong Li, Callum Duncan, Michael Golden and Carlo Leifert 267 found on all five sections of pi... more ... Hong Li, Callum Duncan, Michael Golden and Carlo Leifert 267 found on all five sections of pig tongue, explaining the uniformity of nitrite production over the tongue surface. ... Pharm., 1995, 39, 460 3. Duncan, C., H. Dougall, P. Johnston, S. Green, R. Brogan, C. Leifert, L. Smith. ...

Managing Risks of Nitrates to Humans and the Environment, 1999

... Callum Duncan, Hong Li, Denise Kelly, Michael Golden and Carlo Leifert 293 " Nitrate... more ... Callum Duncan, Hong Li, Denise Kelly, Michael Golden and Carlo Leifert 293 " Nitrate concentration • lOOjiM rf= 0.917 200| iM A 4 (M (| lM • SOOuM ... Means and SEM are from five determinations 3. Duncan, C., H. Dougall, P. Johnston, S. Green, R. Brogan, C. Leifert, L. Smith, ...

BMC Research Notes, 2011

Endogenous nitric oxide (NO) kills bacteria and other organisms as part of the innate immune resp... more Endogenous nitric oxide (NO) kills bacteria and other organisms as part of the innate immune response. When nitrite is exposed to low pH, NO is generated and has been used as an NO delivery system to treat skin infections. We demonstrated eradication of MRSA carriage from wounds using a topical formulation of citric acid (4.5%) and sodium nitrite (3%) creams co-applied for 5 days to 15 wounds in an observational prospective pilot study of 8 patients. Following treatment with topical citric acid and sodium nitrite, 9 of 15 wounds (60%) and 3 of 8 patients (37%) were cleared of infection. MRSA isolates from these patients were all sensitive to acidified nitrite in vitro compared to methicillin-sensitive S. aureus and a reference strain of MRSA. Nitric oxide and acidified nitrite offer a novel therapy for control of MRSA in wounds. Wounds that were not cleared of infection may have been re-contaminated or the bioavailability of acidified nitrite impaired by local factors in the tissue.

In this workshop, we will summarize the results of the QLIF project on food safety issues. The pa... more In this workshop, we will summarize the results of the QLIF project on food safety issues. The participants discuss safety problems related to organic and low input standards and techniques for both animal and plant products. They will relate the findings to consumers’ perception and concern. Improved production and processing techniques will be suggested.

Der Einfluß von Infektionen mit Phytophthora infestans auf den Ertrag und die Qualität des ökolog... more Der Einfluß von Infektionen mit Phytophthora infestans auf den Ertrag und die Qualität des ökologischen Kartoffelanbaus ist sehr variabel. Die Verluste reichen von geringen Effekten bis zu vollständigen Ertragsverlusten. Der Einfluß der Phytophthora-Infektion auf den Ertrag ist u. U. bei der Wahl der „richtigen Sorte“ von geringerer Bedeutung, wenn durch eine systemimmanente Stickstoffakkumulation und –angebot die Kartoffeln in der Knollenbildungsphase Mitte Juni - Anf. Juli gut mit Stickstoff versorgt sind, um eine hohe Knollenbildung und –ausbildung zu gewährleisten. Im Rahmen eines EU-Projektes werden in 2-jährigen Feldversuchen (2002/2003) an zwei Standorten (Deutschland und Niederlande) Untersuchungen zum Effekt der Fruchtfolgestellung von Kartoffeln verschiedenen Kollenansatztyps mit Kleegras als Vorfrucht oder Vorvorfrucht(Vorfrucht Weizen) in Wechselwirkung zum Befall mit P. infestans vorgenommen sowie in Großbritannien umfangreiche Düngeversuche angelegt. Ziel ist es, die A...

The British journal of nutrition, Jan 16, 2016

Demand for organic milk is partially driven by consumer perceptions that it is more nutritious. H... more Demand for organic milk is partially driven by consumer perceptions that it is more nutritious. However, there is still considerable uncertainty over whether the use of organic production standards affects milk quality. Here we report results of meta-analyses based on 170 published studies comparing the nutrient content of organic and conventional bovine milk. There were no significant differences in total SFA and MUFA concentrations between organic and conventional milk. However, concentrations of total PUFA and n-3 PUFA were significantly higher in organic milk, by an estimated 7 (95 % CI ���1, 15) % and 56 (95 % CI 38, 74) %, respectively. Concentrations of ��-linolenic acid (ALA), very long-chain n-3 fatty acids (EPA+DPA+DHA) and conjugated linoleic acid were also significantly higher in organic milk, by an 69 (95 % CI 53, 84) %, 57 (95 % CI 27, 87) % and 41 (95 % CI 14, 68) %, respectively. As there were no significant differences in total n-6 PUFA and linoleic acid (LA) concen...

The British journal of nutrition, Jan 16, 2016

Demand for organic meat is partially driven by consumer perceptions that organic foods are more n... more Demand for organic meat is partially driven by consumer perceptions that organic foods are more nutritious than non-organic foods. However, there have been no systematic reviews comparing specifically the nutrient content of organic and conventionally produced meat. In this study, we report results of a meta-analysis based on sixty-seven published studies comparing the composition of organic and non-organic meat products. For many nutritionally relevant compounds (e.g. minerals, antioxidants and most individual fatty acids (FA)), the evidence base was too weak for meaningful meta-analyses. However, significant differences in FA profiles were detected when data from all livestock species were pooled. Concentrations of SFA and MUFA were similar or slightly lower, respectively, in organic compared with conventional meat. Larger differences were detected for total PUFA and n-3 PUFA, which were an estimated 23 (95 % CI 11, 35) % and 47 (95 % CI 10, 84) % higher in organic meat, respectiv...

Soil samples containing resting structures of fungal crop pathogens (Verticillium dahliae, Sclero... more Soil samples containing resting structures of fungal crop pathogens (Verticillium dahliae, Sclerotinia sclerotiorum, Sclerotium cepivorum, Pythium ultimum), potato cyst nematodes ( Globodera rostochiensis and Globodera pallida) and weeds (Chenopodium album and Agropyron repens) were treated with aerated steam in the laboratory at temperatures ranging from 50-80 o C in a specially constructed apparatus. Steaming at 50 or 60 o C for three minutes, followed by an eight-minute resting period in the steamed soil and immediate removal from the soil thereafter, resulted in 100% kill of all weeds, fungi and nematodes. Low temperature/ short duration soil steaming could become a sustainable alternative to chemical or high-temperature steam soil disinfestation.

Oral Microbiology and Immunology, Feb 1, 2007

Thompson, I.; Carter, P.; Whiteley, A.; Bailey, M.; Leifert, C.; Killham, K.. 2007 Salivary nitra... more Thompson, I.; Carter, P.; Whiteley, A.; Bailey, M.; Leifert, C.; Killham, K.. 2007 Salivary nitrate -An ecological factor in reducing oral acidity. Oral Microbiology and Immunology, 22 (1). Background/aims: Human oral cavities represent a novel environment with a constant supply of concentrated nitrate. For humans, over eighty percent of dietary nitrate originates from fruit and vegetables. With a healthy, balanced diet rich in fruit and vegetables, the concentration of nitrate in saliva can reach up to more than three times the European drinking water standard. The physiological function of the active excretion of salivary nitrate is unknown. Furthermore, little is known of the ecological function of oral nitrate and the effect on the oral environment during its subsequent oral microbial conversions. The objectives of the research were to investigate the effect on salivary pH coupled with oral microbial nitrate and/or nitrite reduction. Methods: Human saliva samples were incubated anaerobically in the presence of 111.0 mM glucose (2%), with and without 1.5 mM nitrate/nitrite, and with pH and nitrate/nitrite consumption measured during the time course of the incubations.

Agricultural and Forest Entomology, 2015

1 The decline of bumblebees in Europe has been linked primarily to agricultural intensification, ... more 1 The decline of bumblebees in Europe has been linked primarily to agricultural intensification, although climate change also has the potential to disrupt plant-pollinator interactions, partly through an increased frequency of extreme short-term weather events. There have been few attempts to use time-series models to determine meteorological variables affecting forager activity at hourly time periods over several months. 2 Time-series models require large datasets to be reliable. We describe the use of infrared detectors at nest entrances to record forager exits/returns from 36 captive colonies of Bombus terrestris audax on a mixed farm in northern England, recording over a 78-day period. 3 Over 1.73 million individual records of forager activity were obtained. These were aggregated into 1872 hourly blocks and analyzed with autoregressive time-series models that used nine meteorological factors as explanatory variables. 4 Forager activity was positively linked to air temperature and solar elevation, and negatively associated with rainfall, humidity and wind-speed. The effects of increased variability in meteorological conditions are considered in the context of these results. The time-series models that we describe will be useful in future analyses of the large datasets of foraging behaviour that are becoming available through new technologies such as radio-frequency identification and video tracking.

NJAS - Wageningen Journal of Life Sciences, 2011

In the last decade the main goals of organic dairying have been to attain acceptable levels of mi... more In the last decade the main goals of organic dairying have been to attain acceptable levels of milk production, increase opportunities for animals to perform species own behaviour, resulting in improved animal welfare and animal health, and minimize the use of therapeutic interventions, including the reduction of the (preventive) use of antibiotics. Maintaining animal health without the use of therapeutic interventions is a major challenge for organic dairy farmers. In particular, udder health remains a major problem in both conventional and organic farming. In the QualityLowInputFood (QLIF) project udder health status and management were assessed in different production systems and European regions. These studies suggest that good udder health can be maintained in organic or low-input farming management systems. Novel strategies to control mastitis were evaluated and the potential of using internal teat sealers for the control of environment-associated pathogens was shown. Also oral application of a herd profile based single homeopathic remedy combined with homeopathic silica had a significant effect on cows with a relative low somatic cell count before drying-off. Suckling systems in calf rearing, as an integrated management approach, did not result in better udder health. None of the studies presented identified new variables affecting udder health. QLIF studies also demonstrated the importance of comparing udder health parameters in contrasting organic, low input and conventional production systems, since clear differences in antibiotic use against mastitis could be identified not only between organic and conventional systems, but also among dairy systems used in different EU-countries. Although alternative treatments used in organic systems could not be shown to be fully effective, results suggest that the use of individual or combined alternative strategies to improve udder health on organic or low-input farms warrants further investigation. Based on the results obtained it is recommended that future research should focus on identifying the reasons for variability in udder health between organic farms that use different management protocols to identify 'best current practice' when carrying out this research.

Milicia species (M. excelsa and M. regia, Moraceae, the irokos) are among the most useful indigen... more Milicia species (M. excelsa and M. regia, Moraceae, the irokos) are among the most useful indigenous rain forest tree species in Africa. They are not grown in plantations but extracted from the natural forest at an unsustainable rate. The major constraint on cultivation and afforestation is the gall-forming insect Phytolyma lata, which destroys seedlings through gall formation, causing dieback of the shoot. Genetic diversity studies should aid the design of conservation and resistance-breeding strategies. This study, therefore, aimed to investigate the genetic variability in Milicia from three West African countries and the power of bulk-family DNA in partitioning ofˆgenetic diversity. Genetic variation within and between 5 natural populations of Milicia from Ghana, Cote d'Ivoire and Sierra Leone was investigated using random amplified polymorphic DNA (RAPD) and non-coding chloro-plast DNA sequencing. RAPD analysis of 41 DNA samples with 8 primers produced a total of 74 bands with 40 bands (54.1%) being polymorphic. Dendrogram analysis produced 2 major clusters separating dry and moist / wet ecotypes. Sub-clustering further separated accessions by forest type and / or geographic region. A greater proportion of the total genetic variability was attributed to variation between populations (62.2%) than within Leu populations (37.8%). Sequencing of chloroplast tRNA intron (cptrnL) and intergenic spacer (cpIGS) between Phe cptrnL and tRNA (trnF) did not show any variation. The RAPD analysis suggests that trees from wet / moist sites are mostly M. regia, while those from dry sites are mostly M. excelsa. Sequencing results, however, suggest that the two species are closely related. These results are discussed with reference to conservation strategies.

PROTEOMICS, 2007

Abbreviations: ANOVA, analysis of variance; Hsp, heat shock protein; PCA, principal component ana... more Abbreviations: ANOVA, analysis of variance; Hsp, heat shock protein; PCA, principal component analysis

Journal of Agricultural and Food Chemistry, 2012

In the European integrated research project SAFEFOODS, one of the aims was to further establish t... more In the European integrated research project SAFEFOODS, one of the aims was to further establish the potential of transcriptomics for the assessment of differences between plant varieties grown under different environmental conditions. Making use of the knowledge of cellular processes and interactions is one of the ways to obtain a better understanding of the differences found with transcriptomics. For the present study the potato genotype Santé was grown under both organic and conventional fertilizer, and each combined with either organic or conventional crop protection, giving four different treatments. Samples were derived from the European project QualityLowInputFood (QLIF). Microarray data were analyzed using different statistical tools (multivariate, principal components analysis (PCA); univariate, analysis of variance (ANOVA)) and with pathway analysis (hypergeometric distribution (HGD) and gene set enrichment analysis (GSEA)). Several biological processes were implicated as a result of the different treatments of the plants. Most obvious were the lipoxygenase pathway, with higher expression in organic fertilizer and lower expression in organic crop protection; the starch synthase pathway, with higher expression in both organic crop protection and fertilizer; and the biotic stress pathway, with higher expression in organic fertilizer. This study confirmed that gene expression profiling in combination with pathway analysis can identify and characterize differences between plants grown under different environmental conditions.

Managing Risks of Nitrates to Humans and the Environment, 1999

... Hong Li, Callum Duncan, Michael Golden and Carlo Leifert 267 found on all five sections of pi... more ... Hong Li, Callum Duncan, Michael Golden and Carlo Leifert 267 found on all five sections of pig tongue, explaining the uniformity of nitrite production over the tongue surface. ... Pharm., 1995, 39, 460 3. Duncan, C., H. Dougall, P. Johnston, S. Green, R. Brogan, C. Leifert, L. Smith. ...

Managing Risks of Nitrates to Humans and the Environment, 1999

... Callum Duncan, Hong Li, Denise Kelly, Michael Golden and Carlo Leifert 293 " Nitrate... more ... Callum Duncan, Hong Li, Denise Kelly, Michael Golden and Carlo Leifert 293 " Nitrate concentration • lOOjiM rf= 0.917 200| iM A 4 (M (| lM • SOOuM ... Means and SEM are from five determinations 3. Duncan, C., H. Dougall, P. Johnston, S. Green, R. Brogan, C. Leifert, L. Smith, ...

BMC Research Notes, 2011

Endogenous nitric oxide (NO) kills bacteria and other organisms as part of the innate immune resp... more Endogenous nitric oxide (NO) kills bacteria and other organisms as part of the innate immune response. When nitrite is exposed to low pH, NO is generated and has been used as an NO delivery system to treat skin infections. We demonstrated eradication of MRSA carriage from wounds using a topical formulation of citric acid (4.5%) and sodium nitrite (3%) creams co-applied for 5 days to 15 wounds in an observational prospective pilot study of 8 patients. Following treatment with topical citric acid and sodium nitrite, 9 of 15 wounds (60%) and 3 of 8 patients (37%) were cleared of infection. MRSA isolates from these patients were all sensitive to acidified nitrite in vitro compared to methicillin-sensitive S. aureus and a reference strain of MRSA. Nitric oxide and acidified nitrite offer a novel therapy for control of MRSA in wounds. Wounds that were not cleared of infection may have been re-contaminated or the bioavailability of acidified nitrite impaired by local factors in the tissue.

In this workshop, we will summarize the results of the QLIF project on food safety issues. The pa... more In this workshop, we will summarize the results of the QLIF project on food safety issues. The participants discuss safety problems related to organic and low input standards and techniques for both animal and plant products. They will relate the findings to consumers’ perception and concern. Improved production and processing techniques will be suggested.

Der Einfluß von Infektionen mit Phytophthora infestans auf den Ertrag und die Qualität des ökolog... more Der Einfluß von Infektionen mit Phytophthora infestans auf den Ertrag und die Qualität des ökologischen Kartoffelanbaus ist sehr variabel. Die Verluste reichen von geringen Effekten bis zu vollständigen Ertragsverlusten. Der Einfluß der Phytophthora-Infektion auf den Ertrag ist u. U. bei der Wahl der „richtigen Sorte“ von geringerer Bedeutung, wenn durch eine systemimmanente Stickstoffakkumulation und –angebot die Kartoffeln in der Knollenbildungsphase Mitte Juni - Anf. Juli gut mit Stickstoff versorgt sind, um eine hohe Knollenbildung und –ausbildung zu gewährleisten. Im Rahmen eines EU-Projektes werden in 2-jährigen Feldversuchen (2002/2003) an zwei Standorten (Deutschland und Niederlande) Untersuchungen zum Effekt der Fruchtfolgestellung von Kartoffeln verschiedenen Kollenansatztyps mit Kleegras als Vorfrucht oder Vorvorfrucht(Vorfrucht Weizen) in Wechselwirkung zum Befall mit P. infestans vorgenommen sowie in Großbritannien umfangreiche Düngeversuche angelegt. Ziel ist es, die A...

The British journal of nutrition, Jan 16, 2016

Demand for organic milk is partially driven by consumer perceptions that it is more nutritious. H... more Demand for organic milk is partially driven by consumer perceptions that it is more nutritious. However, there is still considerable uncertainty over whether the use of organic production standards affects milk quality. Here we report results of meta-analyses based on 170 published studies comparing the nutrient content of organic and conventional bovine milk. There were no significant differences in total SFA and MUFA concentrations between organic and conventional milk. However, concentrations of total PUFA and n-3 PUFA were significantly higher in organic milk, by an estimated 7 (95 % CI ���1, 15) % and 56 (95 % CI 38, 74) %, respectively. Concentrations of ��-linolenic acid (ALA), very long-chain n-3 fatty acids (EPA+DPA+DHA) and conjugated linoleic acid were also significantly higher in organic milk, by an 69 (95 % CI 53, 84) %, 57 (95 % CI 27, 87) % and 41 (95 % CI 14, 68) %, respectively. As there were no significant differences in total n-6 PUFA and linoleic acid (LA) concen...

The British journal of nutrition, Jan 16, 2016

Demand for organic meat is partially driven by consumer perceptions that organic foods are more n... more Demand for organic meat is partially driven by consumer perceptions that organic foods are more nutritious than non-organic foods. However, there have been no systematic reviews comparing specifically the nutrient content of organic and conventionally produced meat. In this study, we report results of a meta-analysis based on sixty-seven published studies comparing the composition of organic and non-organic meat products. For many nutritionally relevant compounds (e.g. minerals, antioxidants and most individual fatty acids (FA)), the evidence base was too weak for meaningful meta-analyses. However, significant differences in FA profiles were detected when data from all livestock species were pooled. Concentrations of SFA and MUFA were similar or slightly lower, respectively, in organic compared with conventional meat. Larger differences were detected for total PUFA and n-3 PUFA, which were an estimated 23 (95 % CI 11, 35) % and 47 (95 % CI 10, 84) % higher in organic meat, respectiv...

Soil samples containing resting structures of fungal crop pathogens (Verticillium dahliae, Sclero... more Soil samples containing resting structures of fungal crop pathogens (Verticillium dahliae, Sclerotinia sclerotiorum, Sclerotium cepivorum, Pythium ultimum), potato cyst nematodes ( Globodera rostochiensis and Globodera pallida) and weeds (Chenopodium album and Agropyron repens) were treated with aerated steam in the laboratory at temperatures ranging from 50-80 o C in a specially constructed apparatus. Steaming at 50 or 60 o C for three minutes, followed by an eight-minute resting period in the steamed soil and immediate removal from the soil thereafter, resulted in 100% kill of all weeds, fungi and nematodes. Low temperature/ short duration soil steaming could become a sustainable alternative to chemical or high-temperature steam soil disinfestation.

Oral Microbiology and Immunology, Feb 1, 2007

Thompson, I.; Carter, P.; Whiteley, A.; Bailey, M.; Leifert, C.; Killham, K.. 2007 Salivary nitra... more Thompson, I.; Carter, P.; Whiteley, A.; Bailey, M.; Leifert, C.; Killham, K.. 2007 Salivary nitrate -An ecological factor in reducing oral acidity. Oral Microbiology and Immunology, 22 (1). Background/aims: Human oral cavities represent a novel environment with a constant supply of concentrated nitrate. For humans, over eighty percent of dietary nitrate originates from fruit and vegetables. With a healthy, balanced diet rich in fruit and vegetables, the concentration of nitrate in saliva can reach up to more than three times the European drinking water standard. The physiological function of the active excretion of salivary nitrate is unknown. Furthermore, little is known of the ecological function of oral nitrate and the effect on the oral environment during its subsequent oral microbial conversions. The objectives of the research were to investigate the effect on salivary pH coupled with oral microbial nitrate and/or nitrite reduction. Methods: Human saliva samples were incubated anaerobically in the presence of 111.0 mM glucose (2%), with and without 1.5 mM nitrate/nitrite, and with pH and nitrate/nitrite consumption measured during the time course of the incubations.

Agricultural and Forest Entomology, 2015

1 The decline of bumblebees in Europe has been linked primarily to agricultural intensification, ... more 1 The decline of bumblebees in Europe has been linked primarily to agricultural intensification, although climate change also has the potential to disrupt plant-pollinator interactions, partly through an increased frequency of extreme short-term weather events. There have been few attempts to use time-series models to determine meteorological variables affecting forager activity at hourly time periods over several months. 2 Time-series models require large datasets to be reliable. We describe the use of infrared detectors at nest entrances to record forager exits/returns from 36 captive colonies of Bombus terrestris audax on a mixed farm in northern England, recording over a 78-day period. 3 Over 1.73 million individual records of forager activity were obtained. These were aggregated into 1872 hourly blocks and analyzed with autoregressive time-series models that used nine meteorological factors as explanatory variables. 4 Forager activity was positively linked to air temperature and solar elevation, and negatively associated with rainfall, humidity and wind-speed. The effects of increased variability in meteorological conditions are considered in the context of these results. The time-series models that we describe will be useful in future analyses of the large datasets of foraging behaviour that are becoming available through new technologies such as radio-frequency identification and video tracking.