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1.
Toxins (Basel) ; 15(9)2023 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-37755980

RESUMO

The farming of shellfish plays an important role in providing sustainable economic growth in coastal, rural communities in Scotland and acts as an anchor industry, supporting a range of ancillary jobs in the processing, distribution and exporting industries. The Scottish Government is encouraging shellfish farmers to double their economic contribution by 2030. These farmers face numerous challenges to reach this goal, among which is the problem caused by toxin-producing microplankton that can contaminate their shellfish, leading to harvesting site closure and the recall of product. Food Standards Scotland, a non-ministerial department of the Scottish Government, carries out a monitoring programme for both the toxin-producing microplankton and the toxins in shellfish flesh, with farms being closed when official thresholds for any toxin are breached. The farm remains closed until testing for the problematic toxin alone, often diarrhetic shellfish toxin (DST), shows the site to have dropped below the regulatory threshold. While this programme has proved to be robust, questions remain regarding the other toxins that may be present at a closed site. In this study, we tested archival material collected during site closures but only tested for DSTs as part of the official control monitoring. We found the presence of amnesic shellfish toxin (AST) in low concentrations in the majority of sites tested. In one case, the level of AST breached the official threshold. This finding has implications for AST monitoring programmes around Europe.


Assuntos
Diatomáceas , Toxinas Marinhas , Toxinas Marinhas/toxicidade , Frutos do Mar/análise , Alimentos Marinhos , Aquicultura
2.
JMIR Med Educ ; 8(2): e32597, 2022 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-35380542

RESUMO

Traditional funding models must change as governments decrease funding and often freeze tuition at a domestic level. As a result, universities face an increasing need to diversify their business models, including revenue streams. Therefore, interest in raising significant funds from other sources is stronger than ever, leading to the need for a fundraising approach that is more sophisticated. Medical educators and health professionals are some of the most trusted members of society, and with this paper, the authors aim to raise awareness of the critical role they play in helping universities with their global impact and fundraising efforts.

3.
Ambio ; 51(2): 333-344, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34845624

RESUMO

The changing Arctic environment is affecting zooplankton that support its abundant wildlife. We examined how these changes are influencing a key zooplankton species, Calanus finmarchicus, principally found in the North Atlantic but expatriated to the Arctic. Close to the ice-edge in the Fram Strait, we identified areas that, since the 1980s, are increasingly favourable to C. finmarchicus. Field-sampling revealed part of the population there to be capable of amassing enough reserves to overwinter. Early developmental stages were also present in early summer, suggesting successful local recruitment. This extension to suitable C. finmarchicus habitat is most likely facilitated by the long-term retreat of the ice-edge, allowing phytoplankton to bloom earlier and for longer and through higher temperatures increasing copepod developmental rates. The increased capacity for this species to complete its life-cycle and prosper in the Fram Strait can change community structure, with large consequences to regional food-webs.


Assuntos
Copépodes , Animais , Regiões Árticas , Ecossistema , Cadeia Alimentar , Zooplâncton
4.
J Environ Qual ; 51(4): 589-601, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34115402

RESUMO

Manure generated from livestock production could represent an important source of plant nutrients in substitution of synthetic fertilizer. To evaluate the sustainability of partially substituting synthetic fertilizer with soil organic amendments (OAs) in horticulture, an economic and greenhouse gas (GHG) budget was developed. The boundary for analysis included manure processing (stockpiling vs. composting) and transport and spreading of manure and compost (feedlot and chicken) in intensively cultivated horticultural fields. The OA field application rates were calculated based on the nitrogen supplied by OAs. The GHG budget based on directly measured emissions indicates that the application of composted manure, in combination with reduced fertilizer rate, was always superior to stockpiled manures. Compost treatments showed from 9 to 90% less GHG emissions than stockpiled manure treatments. However, higher costs associated with the purchase and transport of composted manure (three times higher) generated a greater economic burden compared with stockpiled manure and synthetic fertilizer application. The plant nutrient replacement value of the OAs was considered only for the first year of application, and if long-term nutrient release from OAs is taken into account, additional savings are possible. Because the income from soil carbon sequestration initiatives in response to OA application is unlikely to bridge this financial gap, particularly in the short term, this study proposes that future policy should develop methodologies for avoided GHG emissions from OA application. The combined income from soil carbon sequestration and potentially avoided GHG initiatives could incentivize farmers to adopt OAs as a substitute for synthetic fertilizers, thereby promoting more sustainable farming practices.


Assuntos
Compostagem , Gases de Efeito Estufa , Fertilizantes/análise , Humanos , Esterco , Nitrogênio/análise , Solo
5.
Glob Chang Biol ; 27(20): 5383-5391, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34288295

RESUMO

More than 10% of Australia's 49 M ha of grassland is considered degraded, prompting widespread interest in the management of these ecosystems to increase soil carbon (C) sequestration-with an emphasis on long-lived C storage. We know that management practices that increase plant biomass also increase C inputs to the soil, but we lack a quantitative understanding of the fate of soil C inputs into different soil organic carbon (SOC) fractions that have fundamentally different formation pathways and persistence in the soil. Our understanding of the factors that constrain SOC formation in these fractions is also limited, particularly within tropical climates. We used isotopically labelled residue (13 C) to determine the fate of residue C inputs into short-lived particulate organic matter (POM) and more persistent mineral-associated organic matter (MAOM) across a broad climatic gradient (ΔMAT 10°C) with varying soil properties. Climate was the primary driver of aboveground residue mass loss which corresponded to higher residue-derived POM formation. In contrast, MAOM formation efficiency was constrained by soil properties. The differential controls on POM and MAOM formation highlight that a targeted approach to grassland restoration is required; we must identify priority regions for improved grazing management in soils that have a relatively high silt+clay content and cation exchange capacity, with a low C saturation in the silt+clay fraction to deliver long-term SOC sequestration.


Assuntos
Carbono , Solo , Sequestro de Carbono , Ecossistema , Pradaria
6.
PLoS One ; 15(2): e0223031, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32084137

RESUMO

Blue mussels (Mytilus edulis L. 1758) are important components of coastal ecosystems and in the economy of rural and coastal areas. The understanding of their physiological processes at key life stages is important both within food production systems and in the management of wild populations. Lipids are crucial molecules for bivalve growth, but their diversity and roles have not been fully characterised. In this study, traditional lipid profiling techniques, such as fatty acid (FA) and lipid class analysis, are combined to untargeted lipidomics to elucidate the lipid metabolism in newly settled spat fed on a range of diets. The evaluated diets included single strains treatments (Cylindrotheca fusiformis CCAP 1017/2 -CYL, Isochrysis galbana CCAP 927/1- ISO, Monodopsis subterranean CCAP 848/1 -MONO, Nannochloropsis oceanica CCAP 849/10- NANNO) and a commercial algae paste (SP). Spat growth was influenced by the diets, which, according to their efficacy were ranked as follows: ISO>NANNO/CYL>SP>MONO. A higher triacylglycerols (TG) content, ranging from 4.23±0.82 µg mgashfree Dry weight (DW)-1 at the beginning of the trial (T0) to 51±15.3 µg mgashfreeDW-1 in ISO, characterised significant growth in the spat, whereas, a reduction of TG (0.3±0.08 µg mgashfreeDW-1 in MONO), mono unsaturated FA-MUFA (from 8.52±1.02 µg mgFAashfreeDW-1 at T0 to 2.81±1.02 µg mgFAashfreeDW-1 in MONO) and polyunsaturated FA-PUFA (from 17.57±2.24 µg mgFAashfreeDW-1 at T0 to 6.19±2.49 µg mgFAashfreeDW-1 in MONO) content characterised poor performing groups. Untargeted lipidomics evidenced how the availability of dietary essential PUFA did not influence only neutral lipids but also the membrane lipids, with changes in lipid molecular species in relation to the essential PUFA provided via the diet. Such changes have the potential to affect spat production cycle and their ability to respond to the surrounding environment. This study evidenced the advantages of coupling different lipid analysis techniques, as each technique disclosed relevant information on nutritional requirements of M. edulis juveniles, expanding the existing knowledge on the physiology of this important species.


Assuntos
Ecologia/economia , Lipidômica/métodos , Mytilus edulis/química , Necessidades Nutricionais , Animais , Dieta/métodos , Ecossistema , Ácidos Graxos Insaturados/análise , Metabolismo dos Lipídeos
7.
J Theor Biol ; 468: 27-44, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-30753839

RESUMO

Transcription factors are important molecules which control the levels of mRNA and proteins within cells by modulating the process of transcription (the mechanism by which mRNA is produced within cells) and hence translation (the mechanism by which proteins are produced within cells). Transcription factors are part of a wider family of molecular interaction networks known as gene regulatory networks (GRNs) which play an important role in key cellular processes such as cell division and apoptosis (e.g. the p53-Mdm2, NFκB pathways). Transcription factors exert control over molecular levels through feedback mechanisms, with proteins binding to gene sites in the nucleus and either up-regulating or down-regulating production of mRNA. In many GRNs, there is a negative feedback in the network and the transcription rate is reduced. Typically, this leads to the mRNA and protein levels oscillating over time and also spatially between the nucleus and cytoplasm. When experimental data for such systems is analysed, it is observed to be noisy and in many cases the actual numbers of molecules involved are quite low. In order to model such systems accurately and connect with the data in a quantitative way, it is therefore necessary to adopt a stochastic approach as well as take into account the spatial aspect of the problem. In this paper, we extend previous work in the area by formulating and analysing stochastic spatio-temporal models of synthetic GRNs e.g. repressilators and activator-repressor systems.


Assuntos
Redes Reguladoras de Genes , Genes Sintéticos , Modelos Genéticos , Simulação por Computador , Difusão , Regiões Promotoras Genéticas/genética , Proteínas Repressoras/metabolismo , Processos Estocásticos
8.
Toxins (Basel) ; 10(10)2018 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-30274219

RESUMO

Diarrhetic shellfish toxins produced by the dinoflagellate genus Dinophysis are a major problem for the shellfish industry worldwide. Separate species of the genus have been associated with the production of different analogues of the okadaic acid group of toxins. To evaluate the spatial and temporal variability of Dinophysis species and toxins in the important shellfish-harvesting region of the Scottish west coast, we analysed data collected from 1996 to 2017 in two contrasting locations: Loch Ewe and the Clyde Sea. Seasonal studies were also undertaken, in Loch Ewe in both 2001 and 2002, and in the Clyde in 2015. Dinophysis acuminata was present throughout the growing season during every year of the study, with blooms typically occurring between May and September at both locations. The appearance of D. acuta was interannually sporadic and, when present, was most abundant in the late summer and autumn. The Clyde field study in 2015 indicated the importance of a temperature front in the formation of a D. acuta bloom. A shift in toxin profiles of common mussels (Mytilus edulis) tested during regulatory monitoring was evident, with a proportional decrease in okadaic acid (OA) and dinophysistoxin-1 (DTX1) and an increase in dinophysistoxin-2 (DTX2) occurring when D. acuta became dominant. Routine enumeration of Dinophysis to species level could provide early warning of potential contamination of shellfish with DTX2 and thus determine the choice of the most suitable kit for effective end-product testing.


Assuntos
Bivalves/química , Dinoflagellida/isolamento & purificação , Toxinas Marinhas/análise , Ácido Okadáico/análise , Piranos/análise , Poluentes da Água/análise , Animais , Monitoramento Ambiental , Contaminação de Alimentos/análise , Escócia , Alimentos Marinhos/análise , Intoxicação por Frutos do Mar
9.
FEMS Microbiol Ecol ; 94(10)2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30084997

RESUMO

Recent observations in polar marine waters have shown that a large fraction of primary production may be lost to respiration by planktonic bacteria due to very low bacterial growth efficiencies in cold waters. Here we report that sea temperature may be a key factor (but not the only one) influencing the interaction between bacteria and primary production in North Atlantic and Arctic waters, suggesting that low primary production rates could not sustain bacterial carbon demand in the coldest Arctic waters. The use of freshly produced phytoplankton exudate by bacteria in early- and mid-summer was assessed, together with the bacterial uptake of dissolved inorganic nitrogen (DIN = nitrate and ammonium), in surface waters along a latitudinal gradient from the North Sea to the Arctic sea ice. Bacterial production was independent of the low primary production measured in the coldest waters. Under these conditions, heterotrophic bacteria can consume a large fraction of DIN and N-rich organic matter, making them strong contributors to N fluxes in these waters.


Assuntos
Bactérias/crescimento & desenvolvimento , Fitoplâncton/crescimento & desenvolvimento , Água do Mar/microbiologia , Regiões Árticas , Bactérias/metabolismo , Carbono/metabolismo , Processos Heterotróficos , Interações Microbianas , Nitrogênio/metabolismo , Mar do Norte , Fitoplâncton/metabolismo , Estações do Ano
10.
Bull Math Biol ; 80(5): 1366-1403, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28634857

RESUMO

In this paper, we present two mathematical models related to different aspects and scales of cancer growth. The first model is a stochastic spatiotemporal model of both a synthetic gene regulatory network (the example of a three-gene repressilator is given) and an actual gene regulatory network, the NF-[Formula: see text]B pathway. The second model is a force-based individual-based model of the development of a solid avascular tumour with specific application to tumour cords, i.e. a mass of cancer cells growing around a central blood vessel. In each case, we compare our computational simulation results with experimental data. In the final discussion section, we outline how to take the work forward through the development of a multiscale model focussed at the cell level. This would incorporate key intracellular signalling pathways associated with cancer within each cell (e.g. p53-Mdm2, NF-[Formula: see text]B) and through the use of high-performance computing be capable of simulating up to [Formula: see text] cells, i.e. the tissue scale. In this way, mathematical models at multiple scales would be combined to formulate a multiscale computational model.


Assuntos
Modelos Biológicos , Neoplasias/patologia , Animais , Simulação por Computador , Redes Reguladoras de Genes , Humanos , Conceitos Matemáticos , Neoplasias/genética , Transdução de Sinais , Análise Espaço-Temporal , Processos Estocásticos
11.
Harmful Algae ; 69: 1-17, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-29122238

RESUMO

Fjordic coastlines provide an ideal protected environment for both finfish and shellfish aquaculture operations. This study reports the results of a cruise to the Scottish Clyde Sea, and associated fjordic sea lochs, that coincided with blooms of the diarrhetic shellfish toxin producing dinoflagellate Dinophysis acuta and the diatom genus Chaetoceros, that can generate finfish mortalities. Unusually, D. acuta reached one order of magnitude higher cell abundance in the water column (2840cellsL-1) than the more common Dinophysis acuminata (200cellsL-1) and was linked with elevated shellfish toxicity (maximum 601±237µg OA eq/kg shellfish flesh) which caused shellfish harvesting closures in the region. Significant correlations between D. acuta abundance and that of Mesodinium rubrum were also observed across the cruise transect potentially supporting bloom formation of the mixotrophic D. acuta. Significant spatial variability in phytoplankton that was related to physical characteristics of the water column was observed, with a temperature-driven frontal region at the mouth of Loch Fyne being important in the development of the D. acuta, but not the Chaetoceros bloom. The front also provided important protection to the aquaculture located within the loch, with neither of the blooms encroaching within it. Analysis based on a particle-tracking model confirms the importance of the front to cell transport and shows significant inter-annual differences in advection within the region, that are important to the harmful algal bloom risk therein.


Assuntos
Conservação dos Recursos Naturais , Diatomáceas/isolamento & purificação , Dinoflagellida/isolamento & purificação , Proliferação Nociva de Algas/fisiologia , Água , Geografia , Análise Multivariada , Oceanografia , Fitoplâncton/metabolismo , Pigmentos Biológicos/análise , Salinidade , Comunicações Via Satélite , Escócia , Temperatura
12.
Biogeochemistry ; 134(1): 125-145, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-32025070

RESUMO

Dissolved organic nitrogen (DON) is recognised as an important N source for phytoplankton. However, its relative importance for phytoplankton nutrition and community composition has not been studied comprehensively. This study, conducted in a typical Scottish fjord, representative of near-pristine coastal environments, evaluates the utilisation of DON and dissolved inorganic nitrogen (DIN) by different microbial size fractions and the relationship of phytoplankton community composition with DON and other parameters. The study demonstrated that DON was important in supporting phytoplankton throughout the yearly production cycle. The higher-than-expected urea uptake rates and large fraction of the spring bloom production supported by DON suggested that organic N not only contributes to regenerated production and to the nutrition of the small phytoplankton fraction, but can also contribute substantially to new production of the larger phytoplankton in coastal waters. Multivariate statistical techniques revealed two phytoplankton assemblages with peaks in abundance at different times of the year: a spring group dominated by Skeletonema spp., Thalassiosira spp., and Pseudo-nitzschia spp. group delicatissima; and a summer/autumn group dominated by Chaetoceros spp., Scrippsiella spp., and Pseudo-nitzschia spp. group seriata. The multivariate pattern in community composition and abundance of these taxa was significantly correlated with the multivariate pattern of DON, urea, dissolved free amino acids, DIN, temperature, salinity, and daylength, with daylength and urea being particularly important, suggesting both physical and chemical controls on community composition.

13.
J Feline Med Surg ; 18(3): 250, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27379364
15.
Acta Obstet Gynecol Scand ; 92(12): 1383-7, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24111562

RESUMO

OBJECTIVE: To compare obstetric morbidity of midwife-performed instrumental vaginal deliveries with those performed by doctors. DESIGN: Retrospective cohort study. SETTING: University Hospital, UK. POPULATION: Women undergoing an instrumental vaginal delivery of a singleton infant outside of the operating theater in Aberdeen Maternity Hospital, between June 2005 and June 2010. METHODS: Prospectively entered data were obtained from the hospital data management system. Obstetric outcomes of deliveries by midwives were compared with those performed by any doctor and, in a secondary analysis, with those by junior doctors (fewer than two years at 'registrar' level). Sociodemographic characteristics and clinical outcomes were compared using the chi-squared test, Mann-Whitney U-test and independent sample t-test. MAIN OUTCOME MEASURES: Third- or fourth-degree tears. RESULTS: Among 2540 women identified, 330 (13%) were delivered by midwives. Maternal and clinical characteristics were comparable in each group. Midwives were more likely to use ventouse as their instrument of choice. Women delivered by midwives were less likely to suffer a third- or fourth-degree tears than those delivered by doctors and junior doctors. This difference did not reach statistical significance once adjusted for instrument used: odds ratio 0.6 (95% confidence interval: 0.3-1.2) and odds ratio 0.6 (95% confidence interval: 0.3-1.1), respectively. CONCLUSIONS: Instrumental vaginal deliveries performed by trained midwives are associated with equivalent maternal morbidity to those performed by doctors once adjusted for midwives' preference for the ventouse. This study highlights the potential contribution of an advanced role for midwives in the labor ward.


Assuntos
Parto Obstétrico/métodos , Extração Obstétrica/instrumentação , Tocologia/instrumentação , Complicações do Trabalho de Parto/terapia , Períneo/lesões , Adulto , Estudos de Coortes , Parto Obstétrico/efeitos adversos , Extração Obstétrica/efeitos adversos , Feminino , Humanos , Obstetrícia , Gravidez , Estudos Retrospectivos , Escócia , Estatísticas não Paramétricas
16.
Protist ; 156(1): 45-62, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16048132

RESUMO

Laboratory experiments were conducted to study nitrogen (N) regeneration by the heterotrophic marine dinoflagellate Oxyrrhis marina when ingesting phytoplankton prey of two different species and of two alternative carbon:nitrogen (C:N) ratios. Experiments were conducted in the presence of L-methionine sulfoximine (MSX) which acts as a glutamine synthetase inhibitor. Utilisation by phytoplankton of N regenerated by protozoans and other organisms drives secondary production in marine food webs. However, the rapid utilisation of this N by phytoplankton has previously hampered accurate assessment of the efficiency of protozoan N regeneration. This phenomenon is particularly problematic when the phytoplankton are nutrient stressed and most likely to rapidly utilise N. The use of MSX prevented significant utilisation by phytoplankton of protozoan regenerated N. Hence, by removing the normal pathway of N cycling, we were able to determine the N regeneration efficiency (NRE) of the protozoan. The results suggested that predator NRE could be explained in terms of the relative CN stoichiometry of prey and predator. Using a mathematical model we demonstrated that changing the method used to simulate the NRE of the protozoan trophic level has the potential to markedly modify the predicted dynamics of the simulated microbial food web.


Assuntos
Eucariotos/fisiologia , Nitrogênio/metabolismo , Fitoplâncton/metabolismo , Animais , Disponibilidade Biológica , Eucariotos/metabolismo , Modelos Biológicos , Fitoplâncton/citologia , Fitoplâncton/crescimento & desenvolvimento
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