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1.
Nat Commun ; 14(1): 1863, 2023 04 03.
Article in English | MEDLINE | ID: mdl-37012228

ABSTRACT

Schistosomiasis is a parasitic disease affecting over 200 million people in multiple organs, including the lungs. Despite this, there is little understanding of pulmonary immune responses during schistosomiasis. Here, we show type-2 dominated lung immune responses in both patent (egg producing) and pre-patent (larval lung migration) murine Schistosoma mansoni (S. mansoni) infection. Human pre-patent S. mansoni infection pulmonary (sputum) samples revealed a mixed type-1/type-2 inflammatory cytokine profile, whilst a case-control study showed no significant pulmonary cytokine changes in endemic patent infection. However, schistosomiasis induced expansion of pulmonary type-2 conventional dendritic cells (cDC2s) in human and murine hosts, at both infection stages. Further, cDC2s were required for type-2 pulmonary inflammation in murine pre-patent or patent infection. These data elevate our fundamental understanding of pulmonary immune responses during schistosomiasis, which may be important for future vaccine design, as well as for understanding links between schistosomiasis and other lung diseases.


Subject(s)
Pneumonia , Schistosomiasis mansoni , Schistosomiasis , Humans , Mice , Animals , Schistosoma mansoni/physiology , Case-Control Studies , Schistosomiasis/parasitology , Cytokines , Dendritic Cells
2.
Arch Pediatr ; 29(8): 548-553, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36283887

ABSTRACT

AIMS: During adolescence, a minority of adolescents with type 1 diabetes have persistent and serious poor metabolic control. The main cause of poorly controlled diabetes during adolescence seems to be poor adherence to therapy. The reasons are intertwined between social, family, psychological, and other factors. The aim of our qualitative study was to describe the characteristics of adolescents with chronic poorly controlled diabetes and those of their families. METHODS: We conducted 10 semi-structured interviews with adolescents aged 12-18 years and whose annual average hemoglobin A1c was greater than or equal to 9.5%. Six semi-structured interviews were conducted with parents (either with both or one parent). Interviews were then analyzed according to the comprehensive microanalysis method. RESULTS: We selected three recurrent themes: family life and diabetes, diabetes care and issues, and negative representations of the disease. Family situations were often complex, with limited involvement by fathers and many conflicts regarding medical care. Adolescents were disinvested from day-to-day care although they were aware of the possible long-term complications. Adolescents and their families had a very negative outlook of and experience with diabetes. CONCLUSION: The study highlighted family issues and difficult disease-related experiences among adolescents with persistent and poorly controlled diabetes. As a part of a comprehensive medical approach, it seems necessary to take into consideration the daily care of patients with diabetes within their unique family dynamic.


Subject(s)
Diabetes Mellitus, Type 1 , Humans , Adolescent , Diabetes Mellitus, Type 1/therapy , Diabetes Mellitus, Type 1/psychology , Glycated Hemoglobin/analysis , Qualitative Research , Parents/psychology
3.
Arch Pediatr ; 25(6): 383-388, 2018 Aug.
Article in English | MEDLINE | ID: mdl-30041886

ABSTRACT

OBJECTIVES: Mortality rates of very preterm infants may vary considerably between healthcare facilities depending on the neonates' place of inclusion in the cohort study. The objective of this study was to compare the mortality rates of live-born extremely preterm neonates observed in two French tertiary referral hospitals, taking into account the occurrence of neonatal death both in the delivery room and in the neonatal intensive care unit (NICU). METHODS: Retrospective observational study including all pregnancy terminations, stillbirths and live-born infants within a 22- to 26-week 0/6 gestational age range was registered by two French level 3 university centers between 2009 and 2013. The mortality rates were compared between the two centers according to two places of inclusion: either the delivery room or the NICU. RESULTS: A total of 344 infants were born at center A and 160 infants were born at center B. Among the live-born neonates, the rates of neonatal death were similar in center A (54/125, 43.2%) and center B (33/69, 47.8%; P=0.54). However, neonatal death occurred significantly more often in the delivery room at center A (31/54, 57.4%) than at center B (6/33, 18.2%; P<0.001). Finally, the neonatal death rate of live-born very preterm neonates admitted to the NICU was significantly lower in center A (25/94, 26.6%) than in center B (27/63, 42.9%; P=0.03). CONCLUSIONS: This study points out how the inclusion of deaths in the delivery room when comparing neonatal death rates can lead to a substantial bias in benchmarking studies. Center A and center B each endorsed one of the two models of preferential place of neonatal death (delivery room or NICU) detailed in European studies. The reasons behind the two different models and their impact on how parents perceive supporting their neonate need further investigation.


Subject(s)
Delivery Rooms/statistics & numerical data , Infant Mortality , Intensive Care Units, Neonatal/statistics & numerical data , Female , France , Humans , Infant , Infant, Extremely Premature , Infant, Newborn , Pregnancy , Registries , Retrospective Studies , Tertiary Care Centers/statistics & numerical data
4.
Space Weather ; 16(11): 1644-1667, 2018 Oct 17.
Article in English | MEDLINE | ID: mdl-32021590

ABSTRACT

In this paper we present an assessment of the status of models of the global Solar Wind in the inner heliosphere. We limit our discussion to the class of models designed to provide solar wind forecasts, excluding those designed for the purpose of testing physical processes in idealized configurations. In addition, we limit our discussion to modeling of the 'ambient' wind in the absence of coronal mass ejections. In this assessment we cover use of the models both in forecast mode and as tools for scientific research. We present a brief history of the development of these models, discussing the range of physical approximations in use. We discuss the limitations of the data inputs available to these models and its impact on their quality. We also discuss current model development trends.

5.
Nat Commun ; 8(1): 1510, 2017 11 15.
Article in English | MEDLINE | ID: mdl-29142230

ABSTRACT

Spondyloarthritis encompasses a group of common inflammatory diseases thought to be driven by IL-17A-secreting type-17 lymphocytes. Here we show increased numbers of GM-CSF-producing CD4 and CD8 lymphocytes in the blood and joints of patients with spondyloarthritis, and increased numbers of IL-17A+GM-CSF+ double-producing CD4, CD8, γδ and NK cells. GM-CSF production in CD4 T cells occurs both independently and in combination with classical Th1 and Th17 cytokines. Type 3 innate lymphoid cells producing predominantly GM-CSF are expanded in synovial tissues from patients with spondyloarthritis. GM-CSF+CD4+ cells, isolated using a triple cytokine capture approach, have a specific transcriptional signature. Both GM-CSF+ and IL-17A+GM-CSF+ double-producing CD4 T cells express increased levels of GPR65, a proton-sensing receptor associated with spondyloarthritis in genome-wide association studies and pathogenicity in murine inflammatory disease models. Silencing GPR65 in primary CD4 T cells reduces GM-CSF production. GM-CSF and GPR65 may thus serve as targets for therapeutic intervention of spondyloarthritis.


Subject(s)
CD4-Positive T-Lymphocytes/metabolism , Granulocyte-Macrophage Colony-Stimulating Factor/genetics , Spondylarthritis/genetics , Transcriptome , Adult , Aged , Aged, 80 and over , Animals , Female , Genome-Wide Association Study , Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Humans , Male , Mice , Middle Aged , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism , Spondylarthritis/metabolism , Young Adult
6.
Ann Rheum Dis ; 76(3): 620-625, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28039186

ABSTRACT

OBJECTIVE: To determine the microRNA (miR) signature in ankylosing spondylitis (AS) T helper (Th)17 cells. METHODS: Interleukin (IL)-17A-producing CD4+ T cells from patients with AS and healthy controls were FACS-sorted for miR sequencing and qPCR validation. miR-10b function was determined by miR mimic expression followed by cytokine measurement, transcriptome analysis, qPCR and luciferase assays. RESULTS: AS Th17 cells exhibited a miR signature characterised by upregulation of miR-155-5p, miR-210-3p and miR-10b. miR-10b has not been described previously in Th17 cells and was selected for further characterisation. miR-10b is transiently induced in in vitro differentiated Th17 cells. Transcriptome, qPCR and luciferase assays suggest that MAP3K7 is targeted by miR-10b. Both miR-10b overexpression and MAP3K7 silencing inhibited production of IL-17A by both total CD4 and differentiating Th17 cells. CONCLUSIONS: AS Th17 cells have a specific miR signature and upregulate miR-10b in vitro. Our data suggest that miR-10b is upregulated by proinflammatory cytokines and may act as a feedback loop to suppress IL-17A by targeting MAP3K7. miR-10b is a potential therapeutic candidate to suppress pathogenic Th17 cell function in patients with AS.


Subject(s)
Interleukin-17/biosynthesis , MAP Kinase Kinase Kinases/antagonists & inhibitors , MicroRNAs/genetics , MicroRNAs/metabolism , Th17 Cells/metabolism , Up-Regulation , Adult , Aged , CD4-Positive T-Lymphocytes/metabolism , Case-Control Studies , Cells, Cultured , Female , Gene Silencing , Humans , Interleukin-6/pharmacology , MAP Kinase Kinase Kinases/genetics , MAP Kinase Kinase Kinases/metabolism , Male , Middle Aged , Spondylitis, Ankylosing , Transcriptome/drug effects , Tumor Necrosis Factor-alpha/pharmacology , Young Adult
7.
J Econ Entomol ; 109(6): 2561-2571, 2016 12.
Article in English | MEDLINE | ID: mdl-27986943

ABSTRACT

The flight of the lesser grain borer, Rhyzopertha dominica (F.), near grain storages and at distances from them, was investigated to assess the potential of these beetles to infest grain and spread insecticide resistance genes. We caught R. dominica in pheromone-baited flight traps (and blank controls) set at storages, in fields away from storages, and in native vegetation across a 12-mo period. A functional set of highly polymorphic microsatellite markers was developed, enabling population genetic analyses on the trapped beetles. Pheromone-baited traps caught just as many R. dominica adults at least 1 km from grain storages as were caught adjacent to grain storages. Samples of beetles caught were genetically homogeneous across the study area (over 7,000 km2) in South Queensland, Australia. However, a change in genetic structure was detected at one bulk storage site. Subsequent analysis detected a heterozygous excess, which indicated a population bottleneck. Only a few beetles were caught during the winter months of June and July. To assess the mating status and potential fecundity of dispersing R. dominica females, we captured beetles as they left grain storages and quantified offspring production and life span in the laboratory. Nearly all (95%) of these dispersing females had mated and these produced an average of 242 offspring. We demonstrated that R. dominica populations in the study area display a high degree of connectivity and this is a result of the active dispersal of mated individuals of high potential fecundity.


Subject(s)
Animal Distribution , Coleoptera/physiology , Genetic Variation , Sexual Behavior, Animal , Animals , Coleoptera/genetics , Female , Fertility , Insect Control , Male , Pheromones/pharmacology , Queensland , Spatio-Temporal Analysis
8.
J Econ Entomol ; 109(5): 2221-8, 2016 10.
Article in English | MEDLINE | ID: mdl-27515594

ABSTRACT

Effective pest management relies on accurate delimitation of species and, beyond this, on accurate species identification. Mitochondrial COI sequences are useful for providing initial indications in delimiting species but, despite acknowledged limitations in the method, many studies involving COI sequences and species problems remain unresolved. Here we illustrate how such impasses can be resolved with microsatellite and nuclear sequence data, to assess more directly the amount of gene flow between divergent lineages. We use a population genetics approach to test for random mating between two 8 ± 2% divergent COI lineages of the rusty grain beetle, Cryptolestes ferrugineus (Stephens). This species has become strongly resistant to phosphine, a fumigant used worldwide for disinfesting grain. The possibility of cryptic species would have significant consequences for resistance management, especially if resistance was confined to one mitochondrial lineage. We find no evidence of restricted gene flow or nonrandom mating across the two COI lineages of these beetles, rather we hypothesize that historic population structure associated with early Pleistocene climate changes likely contributed to divergent lineages within this species.


Subject(s)
Coleoptera/physiology , Genetic Variation , Insecticide Resistance , Insecticides/pharmacology , Phosphines/pharmacology , Sexual Behavior, Animal , Animals , Coleoptera/drug effects , Coleoptera/genetics , Electron Transport Complex IV/genetics , Insect Proteins/genetics , Microsatellite Repeats , Mitochondrial Proteins/genetics , Phylogeny , Sequence Analysis, DNA
9.
Avian Pathol ; 45(5): 559-68, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27171857

ABSTRACT

Data on husbandry practices, performance, disease and drug use were collected during a cross-sectional survey of 89 poultry meat farms in England and Wales to provide information on possible risk factors for the occurrence of fluoroquinolone (FQ)-resistant bacteria. Faeces samples were used to classify farms as "affected" or "not affected" by FQ-resistant (FQr) Escherichia coli or Campylobacter spp. Risk factor analysis identified the use of FQ on the farms as having by far the strongest association, among the factors considered, with the occurrence of FQr bacteria. Resistant E. coli and/or Campylobacter spp. were found on 86% of the farms with a history of FQ use. However, a substantial proportion of farms with no history of FQ use also yielded FQr organisms, suggesting that resistant bacteria may transfer between farms. Further analysis suggested that for Campylobacter spp., on-farm hygiene, cleaning and disinfection between batches of birds and wildlife control were of most significance. By contrast, for E. coli biosecurity from external contamination was of particular importance, although the modelling indicated that other factors were likely to be involved. Detailed studies on a small number of sites showed that FQr E. coli can survive routine cleaning and disinfection. It appears difficult to avoid the occurrence of resistant bacteria when FQ are used on a farm, but the present findings provide evidence to support recommendations to reduce the substantial risk of the incidental acquisition of such resistance by farms where FQ are not used.


Subject(s)
Anti-Bacterial Agents/pharmacology , Campylobacter/drug effects , Escherichia coli/drug effects , Fluoroquinolones/pharmacology , Poultry Diseases/microbiology , Poultry/microbiology , Animal Husbandry , Animals , Campylobacter/isolation & purification , Cross-Sectional Studies , England/epidemiology , Escherichia coli/isolation & purification , Farms , Feces/microbiology , Poultry Diseases/epidemiology , Prevalence , Risk Factors , Wales/epidemiology
10.
Proc Biol Sci ; 280(1760): 20130558, 2013 Jun 07.
Article in English | MEDLINE | ID: mdl-23576792

ABSTRACT

One theory to explain the existence of conspicuous solicitation is that it is a way for young to 'blackmail' carers into provisioning them, by threatening their own destruction. Fledgling birds offer a unique opportunity to investigate the 'blackmail theory', as their mobility enables them to influence the predation risk they face. We investigated a novel solicitation behaviour in fledgling pied babblers (Turdoides bicolor), where fledglings use their location to influence provisioning rates. We show that fledglings face a trade-off: the ground is a much more profitable location in terms of provisioning rate from adult carers, but they are at greater risk from predators owing to their limited flying ability and slow response to alarm calls. Young babbler fledglings move to the ground when hungry, signalling their state, and this stimulates adults to increase their provisioning rates. Once satiated, fledglings return to the safety of cover. By experimentally increasing terrestrial predation risk, we found that adults increased their provisioning rate to terrestrial but not arboreal fledglings. Thus, by moving to a riskier location, fledglings revealed their need and were able to manipulate adults to achieve higher provisioning rates. These results provide support for the 'blackmail theory'.


Subject(s)
Appetitive Behavior/physiology , Conflict, Psychological , Models, Biological , Nesting Behavior/physiology , Passeriformes/physiology , Age Factors , Animals , Linear Models , Observation , Predatory Behavior , South Africa
11.
J Microsc ; 251(3): 242-9, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23488932

ABSTRACT

Rho GTPases are well known to regulate cell motility through activation of a variety of downstream effector proteins, including enzymes, adaptor proteins and actin nucleators. The three closely related Rho GTPases RhoA, RhoB and RhoC all have the potential to interact with the same downstream effectors, yet they have substantially different effects on cell shape and migratory properties. Here I review the different ways in which RhoA, RhoB and RhoC expression is regulated in cancer and how they play distinct roles in cancer progression. I describe their main effectors known to contribute to cell motility. Recent results from our laboratory and others indicate that RhoA, RhoB and RhoC can be activated by specific stimuli and act through different effectors to control distinct aspects of cancer cell migration and invasion. This suggests that they each make unique contributions to cancer by participating in different protein complexes.


Subject(s)
Cell Movement , Gene Expression Regulation, Neoplastic , Neoplasms/pathology , rho GTP-Binding Proteins/metabolism , rhoA GTP-Binding Protein/metabolism , rhoB GTP-Binding Protein/metabolism , Cell Line, Tumor , Humans , Male , Prostate , rhoC GTP-Binding Protein
12.
Oncogene ; 32(2): 198-208, 2013 Jan 10.
Article in English | MEDLINE | ID: mdl-22349824

ABSTRACT

NOTCH1 is frequently mutated in T-cell acute lymphoblastic leukaemia (T-ALL), and can stimulate T-ALL cell survival and proliferation. Here we explore the hypothesis that Notch1 also alters T-ALL cell migration. Rho GTPases are well known to regulate cell adhesion and migration. We have analysed the expression levels of Rho GTPases in primary T-ALL samples compared with normal T cells by quantitative PCR. We found that 5 of the 20 human Rho genes are highly and consistently upregulated in T-ALL, and 3 further Rho genes are expressed in T-ALL but not detectable in normal T cells. Of these, RHOU expression is highly correlated with the expression of the Notch1 target DELTEX-1. Inhibition of Notch1 signalling with a γ-secretase inhibitor (GSI) or Notch1 RNA interference reduced RhoU expression in T-ALL cells, whereas constitutively active Notch1 increased RhoU expression. In addition, Notch1 or RhoU depletion, or GSI treatment, inhibits T-ALL cell adhesion, migration and chemotaxis. These results indicate that NOTCH1 mutation stimulates T-ALL cell migration through RhoU upregulation that could contribute to the leukaemia cell dissemination.


Subject(s)
Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/metabolism , Receptor, Notch1/metabolism , rho GTP-Binding Proteins/metabolism , Amyloid Precursor Protein Secretases/antagonists & inhibitors , Amyloid Precursor Protein Secretases/metabolism , Cell Adhesion , Cell Line, Tumor , Cell Movement , Cell Proliferation , Humans , Oligopeptides/pharmacology , RNA Interference , RNA, Small Interfering , Receptor, Notch1/genetics , Signal Transduction , Up-Regulation
14.
Vet Microbiol ; 159(3-4): 390-6, 2012 Oct 12.
Article in English | MEDLINE | ID: mdl-22565009

ABSTRACT

Detection and enumeration of Campylobacter spp. in broiler chicken flocks are key components of research and surveillance studies aimed at reducing Campylobacter infections in people. Direct culture of caecal contents onto selective agar is the typical method used to confirm flock colonisation. Modified charcoal cefoperazone deoxycholate agar (mCCDA) is commonly used for this method, although alternative selective media have been used. Additionally, PCR methods to detect Campylobacter DNA from caecal contents may provide a rapid alternative. However comparative performance data for these methods is limited and therefore required to ensure optimal detection methods for this sample type. In this study, 306 broiler caeca were tested for Campylobacter using direct culture on mCCDA, Skirrows and Preston agars and two real-time PCR methods, one specific for mapA/ceuE regions and another for the flaA gene region. Additionally, the suitability of spread plating and spiral plating methods for enumeration of Campylobacter and the impact of sample storage were assessed. This study confirmed modified CCDA as an optimal media for detection of Campylobacter in broiler caeca. It was significantly more sensitive than Skirrows or Preston agars. This study also demonstrated that the mapA/ceuE PCR had excellent agreement with culture on mCCDA and is a genuine alternative method. Spread plating and spiral plating methods were suitable for enumeration although spiral plating appeared more sensitive for stored samples (72 h). A 1 log reduction in viable Campylobacters was observed in stored samples, therefore storage effects should be considered for quantitative studies with broiler caeca.


Subject(s)
Bacterial Load/methods , Campylobacter Infections/veterinary , Campylobacter/isolation & purification , Chickens , Agar , Animals , Campylobacter/growth & development , Campylobacter/physiology , Cecum/microbiology , Polymerase Chain Reaction/methods , Real-Time Polymerase Chain Reaction
15.
Epidemiol Infect ; 140(5): 916-24, 2012 May.
Article in English | MEDLINE | ID: mdl-21781366

ABSTRACT

Campylobacter is the most common known source of human bacterial enteritis in the developed world and poultry is considered the main source. Broilers often become colonized with Campylobacter during rearing, and then contaminate the farm environment. The objective of this study was to identify Campylobacter-positive environmental reservoirs on farms, as these pose a risk to broiler flocks becoming colonized with Campylobacter. We considered the temporal aspects of exposure and colonization. A longitudinal study monitored six conventional rearing farms over 2 years. The broiler flocks, catchers' equipment, vehicles, shed surrounds, shed entrance, other equipment, farm entrance, other animals, puddles, dead birds, mains water and drinkers were systematically sampled 2-4 times per flock. A multivariable generalized estimating equation model was used to assess associations between contaminated environmental sites and colonized broiler flocks. The associations were adjusted for confounders and other known risk factors. To further assess temporality of contamination, the sequence of contamination of the different environmental sites and the flocks was established. Contaminated shed entrances and anterooms, contaminated drinkers and shedding of Campylobacter by other animals such as cattle, dogs, wildlife and rodents were significantly associated with positive flocks. The reservoir of 'other animals' was also the reservoir most commonly positive before the flock became colonized. The other sites usually became contaminated after the flock was colonized.


Subject(s)
Campylobacter Infections/epidemiology , Campylobacter Infections/veterinary , Campylobacter/isolation & purification , Chickens , Disease Reservoirs , Environmental Microbiology , Poultry Diseases/epidemiology , Animals , Cattle , Dogs , Humans , Longitudinal Studies , Risk Factors
16.
J Appl Microbiol ; 111(1): 233-44, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21535329

ABSTRACT

AIMS: To test the efficacy of enhanced biosecurity measures on poultry farms for reducing environmental contamination with Campylobacter during partial depopulation of broiler flocks prior to normal slaughter age. The study has also evaluated the risk of infection from live-bird transport crates that are routinely cleaned at the slaughterhouse, but may remain contaminated. METHODS AND RESULTS: On-farm sampling and Campylobacter isolation was undertaken to compare the prevalence of contamination on vehicles, equipment and catching personnel during farm visits that took place under normal or enhanced biosecurity. Campylobacters were found in almost all types of sample examined and enhanced biosecurity reduced the prevalence. However, the additional measures failed to prevent colonisation of the flocks. For transport crates, challenge trials involved exposure of broilers to commercially cleaned crates and genotyping of any campylobacters isolated. The birds were rapidly colonised with the same genotypes as those isolated from the cleaned crates. CONCLUSIONS: The enhanced biosecurity measures were insufficient to prevent flock colonisation, and the problem was exacerbated by inadequate cleaning of transport crates at the slaughterhouse. SIGNIFICANCE AND IMPACT OF THE STUDY: Current commercial practices in the United Kingdom facilitate the spread of campylobacters among broiler chicken flocks. Prevention of flock infection appears to require more stringent biosecurity than that studied here.


Subject(s)
Campylobacter Infections/veterinary , Campylobacter/isolation & purification , Chickens , Meat/microbiology , Poultry Diseases/epidemiology , Poultry Diseases/microbiology , Abattoirs , Animals , Campylobacter/classification , Campylobacter/genetics , Campylobacter Infections/epidemiology , Campylobacter Infections/microbiology , Prevalence , United Kingdom
17.
Mol Ecol ; 20(8): 1635-46, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21375637

ABSTRACT

Tribolium castaneum (Herbst) has been used as a model organism to develop and test important ecological and evolutionary concepts and is also a major pest of grain and grain products globally. This beetle species is assumed to be a good colonizer of grain storages through anthropogenic movement of grain, and active dispersal by flight is considered unlikely. Studies using T. castaneum have therefore used confined or walking insects. We combine an ecological study of dispersal with an analysis of gene flow using microsatellites to investigate the spatiotemporal dynamics and adult flight of T. castaneum in an ecological landscape in eastern Australia. Flying beetles were caught in traps at grain storages and in fields at least 1 km from the nearest stored grain at regular intervals for an entire year. Significantly more beetles were trapped at storages than in fields, and almost no beetles were caught in native vegetation reserves many kilometres from the nearest stored grain. Genetic differentiation between beetles caught at storages and in fields was low, indicating that although T. castaneum is predominantly aggregated around grain storages, active dispersal takes place to the extent that significant gene flow occurs between them, mitigating founder effects and genetic drift. By combining ecological and molecular techniques, we reveal much higher levels of active dispersal through adult flight in T. castaneum than previously thought. We conclude that the implications of adult flight to previous and future studies on this model organism warrant consideration.


Subject(s)
Flight, Animal , Gene Flow , Genetic Variation , Tribolium/genetics , Agriculture , Animals , Australia , Environment , Female , Founder Effect , Genotype , Male , Microsatellite Repeats , Seasons
18.
J Theor Biol ; 280(1): 34-42, 2011 Jul 07.
Article in English | MEDLINE | ID: mdl-21439300

ABSTRACT

Endothelial cells respond to fluid flow by elongating in the direction of flow. Cytoskeletal changes and activation of signalling molecules have been extensively studied in this response, including: activation of receptors by mechano-transduction, actin filament alignment in the direction of flow, changes to cell-substratum adhesions, actin-driven lamellipodium extension, and localised activation of Rho GTPases. To study this process we model the force over a single cell and couple this to a model of the Rho GTPases, Rac and Rho, via a Kelvin-body model of mechano-transduction. It is demonstrated that a mechano-transducer can respond to the normal component of the force is likely to be a necessary component of the signalling network in order to establish polarity. Furthermore, the rate-limiting step of Rac1 activation is predicted to be conversion of Rac-GDP to Rac-GTP, rather than activation of upstream components. Modelling illustrates that the aligned endothelial cell morphology could attenuate the signalling network.


Subject(s)
Endothelial Cells/enzymology , Mechanotransduction, Cellular/physiology , Models, Biological , rac1 GTP-Binding Protein/metabolism , Actin Cytoskeleton/metabolism , Animals , Cell Polarity/physiology , Enzyme Activation , Humans , Pseudopodia/metabolism
19.
Br Poult Sci ; 52(1): 30-9, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21337195

ABSTRACT

1. Because thermophilic Campylobacter spp. are common in chicken flocks reared extensively, cross-sectional and longitudinal studies were carried out on organic and free-range farms to determine the onset of colonisation (lag phase) and likely sources of flock infection. 2. For 14 organic and 14 free range flocks, there was a difference in lag phases, with the former being colonized at a mean of 14·1 d in comparison with 31·6 d for the latter. Whereas most free-range flocks became colonized when released on to pasture, those reared organically were usually colonized at the housed brooding stage. 3. Further study of organic flocks on three farms over 7 successive crop cycles confirmed that colonisation was strongly influenced by the prevailing husbandry conditions and was not a consequence of the length of the rearing period. 4. Molecular epidemiological investigations on a farm showing the shortest lag phase, using PFGE typing with two different restriction enzymes (SmaI and KpnI) and flaA SVR sequence typing, revealed that potential sources of colonisation for organic chickens were already present on the farm at the time of chick placement. Such sources included the ante area of the brooding house, surrounding pasture and other livestock being kept on the farm. 5. Overall, the study demonstrated that, under UK conditions, the prevalence of colonisation was greater in extensive flocks (95-100%) than it was for conventional broilers (55%), similar to the situation in other countries, but all three management systems showed comparable levels of caecal carriage in positive birds (log(10)/g 6·2-6·7).


Subject(s)
Campylobacter Infections/veterinary , Chickens/microbiology , Poultry Diseases/transmission , Animal Husbandry/methods , Animals , Campylobacter/isolation & purification , Campylobacter Infections/transmission , Organic Agriculture/methods , Poultry Diseases/microbiology , Time Factors , United Kingdom
20.
J Intellect Disabil Res ; 55(4): 385-91, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21265903

ABSTRACT

BACKGROUND: Although children with intellectual disabilities (ID) often provide accurate witness testimony, jurors tend to perceive their witness statements to be inherently unreliable. METHOD: The current study explored the free recall transcripts of child witnesses with ID who had watched a video clip, relative to those of typically developing (TD) age-matched children, and assessed how mock jurors perceived these transcripts in the absence of knowledge of group (ID or TD) membership. A further aim of this research was to determine whether perceptions of credibility were associated with levels of free recall and witness characteristics (anxiety and mental age). RESULTS: Mock jurors rated the testimony of children with ID as less credible than that of a TD age-matched comparison group. This was largely because of the transcripts of the children with ID containing fewer details than those of the TD children. Anxiety and mental age were found to have no effect on perceived levels of credibility. CONCLUSIONS: It appears that even in the absence of knowledge of whether a child does or does not have ID, this factor still affects perceptions of credibility among mock jurors. Our findings suggest that fundamental differences in the quality of the witness transcripts lead to lower perceptions of credibility for children with ID.


Subject(s)
Intellectual Disability/psychology , Jurisprudence , Mental Recall , Social Perception , Truth Disclosure , Adolescent , Adult , Aged , Analysis of Variance , Attitude , Case-Control Studies , Child , Disabled Children , Female , Humans , Male , Matched-Pair Analysis , Mental Competency , Middle Aged , Reference Values , Single-Blind Method
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