465 research outputs found
Pathogenicity of the root-knot nematode Meloidogyne javanica on potato
Host–parasite relationships and pathogenicity of
Meloidogyne javanica
on potatoes (newly recorded from Malta) were
studied under glasshouse and natural conditions. Potato cvs Cara and Spunta showed a typical susceptible reaction to
M. javanica
under natural and artificial infections, respectively. In potato tubers,
M. javanica
induced feeding sites that
consisted of three to four hypertrophied giant cells per adult female. Infection of feeder roots by the nematode resulted
in mature large galls which usually contained at least one mature female and egg mass. In both tubers and roots, feeding
sites were characterized by giant cells containing granular cytoplasm and many hypertrophied nuclei. Cytoplasm in giant
cells was aggregated alongside the thickened cell walls. Stelar tissues within galls appeared disorganized. The relationship
between initial nematode population density (
P
) [0–64 eggs + second-stage juveniles (J2s) per cm
3
soil] and growth of
cv. Spunta potato seedlings was tested under glasshouse conditions. A Seinhorst model [
y = m
+ (1
−
m
)
z
(
P
−
T
)
] was fitted
to fresh shoot weight and shoot height data of nematode-inoculated and control plants. Tolerance limits (
T
) for fresh
shoot weight and shoot height of cv. Spunta plants infected with
M. javanica
were 0·50 and 0·64 eggs + J2s per cm
3
soil,
respectively. The
m
parameter in that model (i.e. the minimum possible
y
-values) for fresh shoot weight and shoot height
were 0·60 and 0·20, respectively, at
P
= 64 eggs + J2s per cm
3
soil. Root galling was proportional to the initial nematode
population density. Maximum nematode reproduction rate was 51·2 at a moderate initial population density (
P
= 4
eggs + J2s per cm
3
soil).peer-reviewe
Risk of psychotic disorders in migrants to Australia
BACKGROUND: Certain migrant groups are at an increased risk of psychotic disorders compared to the native-born population; however, research to date has mainly been conducted in Europe. Less is known about whether migrants to other countries, with different histories and patterns of migration, such as Australia, are at an increased risk for developing a psychotic disorder. We tested this for first-generation migrants in Melbourne, Victoria. METHODS: This study included all young people aged 15-24 years, residing in a geographically-defined catchment area of north western Melbourne who presented with a first episode of psychosis (FEP) to the Early Psychosis Prevention and Intervention Centre (EPPIC) between 1 January 2011 and 31 December 2016. Data pertaining to the at-risk population were obtained from the Australian 2011 Census and incidence rate ratios were calculated and adjusted for age, sex and social deprivation. RESULTS: In total, 1220 young people presented with an FEP during the 6-year study period, of whom 24.5% were first-generation migrants. We found an increased risk for developing psychotic disorder in migrants from the following regions: Central and West Africa (adjusted incidence rate ratio [aIRR] = 3.53, 95% CI 1.58-7.92), Southern and Eastern Africa (aIRR = 3.06, 95% CI 1.99-4.70) and North Africa (aIRR = 5.03, 95% CI 3.26-7.76). Migrants from maritime South East Asia (aIRR = 0.39, 95% CI 0.23-0.65), China (aIRR = 0.25, 95% CI 0.13-0.48) and Southern Asia (aIRR = 0.44, 95% CI 0.26-0.76) had a decreased risk for developing a psychotic disorder. CONCLUSION: This clear health inequality needs to be addressed by sufficient funding and accessible mental health services for more vulnerable groups. Further research is needed to determine why migrants have an increased risk for developing psychotic disorders
Remotely acting SMCHD1 gene regulatory elements: in silico prediction and identification of potential regulatory variants in patients with FSHD
Background: Facioscapulohumeral dystrophy (FSHD) is commonly associated with contraction of the D4Z4 macro-satellite repeat on chromosome 4q35 (FSHD1) or mutations in the SMCHD1 gene (FSHD2). Recent studies have shown that the clinical manifestation of FSHD1 can be modified by mutations in the SMCHD1 gene within a given family. The absence of either D4Z4 contraction or SMCHD1 mutations in a small cohort of patients suggests that the disease could also be due to disruption of gene regulation. In this study, we postulated that mutations responsible for exerting a modifier effect on FSHD might reside within remotely acting regulatory elements that have the potential to interact at a distance with their cognate gene promoter via chromatin looping. To explore this postulate, genome-wide Hi-C data were used to identify genomic fragments displaying the strongest interaction with the SMCHD1 gene. These fragments were then narrowed down to shorter regions using ENCODE and FANTOM data on transcription factor binding sites and epigenetic marks characteristic of promoters, enhancers and silencers
Recurrent mutation of IGF signalling genes and distinct patterns of genomic rearrangement in osteosarcoma
Osteosarcoma is a primary malignancy of bone that affects children and adults. Here, we present the largest sequencing study of osteosarcoma to date, comprising 112 childhood and adult tumours encompassing all major histological subtypes. A key finding of our study is the identification of mutations in insulin-like growth factor (IGF) signalling genes in 8/112 (7%) of cases. We validate this observation using fluorescence in situ hybridization (FISH) in an additional 87 osteosarcomas, with IGF1 receptor (IGF1R) amplification observed in 14% of tumours. These findings may inform patient selection in future trials of IGF1R inhibitors in osteosarcoma. Analysing patterns of mutation, we identify distinct rearrangement profiles including a process characterized by chromothripsis and amplification. This process operates recurrently at discrete genomic regions and generates driver mutations. It may represent an age-independent mutational mechanism that contributes to the development of osteosarcoma in children and adults alike
Teaching and learning in a multilingual Europe: findings from a cross-European study
School classrooms within the EU are multilingual learning environments. The diversity of pupils in classrooms raises significant challenges for teachers, but to date, there are no data from large-scale surveys that compare views within and across European countries. A bespoke questionnaire was designed to examine views of current classroom learning environments with respect to the multilingualism. The questionnaire was piloted and subsequently completed by 2792 teachers across different European countries. Eleven countries provided sufficient data for analyses. Results from structural equation modelling showed that teachers’ attitudes could be reliably measured across Europe with the use of carefully devised questionnaire, whose loading and factor structure remained invariant across countries. Teachers’ views about multilingualism were most challenged by the numbers of children in their classes, not the percentage of multilingual pupils in the class. Countries differed in how they perceived multilingualism, with their differences leading to distinctive country clusters. Gender and education level (elementary vs. secondary) differences were also observed irrespective of country. These findings enhance our understanding of the role that the characteristics of teachers and their classrooms play in a multilingual setting across diverse European settings. The practical relevance of the results and new opportunities for teacher training are discussed
Correction: Teaching and learning in a multilingual Europe: findings from a cross-European study
The original version of the article unfortunately contained an error. In author’s personal details, middle names were not included in author Hanne B. Søndergaard Knudsen’s name, and the listed articles were therefore incorrect
Teaching and learning in a multilingual Europe: findings from a cross-european study
School classrooms within the EU are multilingual learning environments. The diversity of pupils in classrooms raises significant challenges for teachers, but to date, there are no data from large-scale surveys that compare views within and across European countries. A bespoke questionnaire was designed to examine views of current classroom learning environments with respect to the multilingualism. The questionnaire was piloted and subsequently completed by 2792 teachers across different European countries. Eleven countries provided sufficient data for analyses. Results from structural equation model- ling showed that teachers’ attitudes could be reliably measured across Europe with the use of carefully devised questionnaire, whose loading and factor structure remained invariant across countries. Teachers’ views about multilingualism were most challenged by the numbers of children in their classes, not the percentage of multilingual pupils in the class. Countries differed in how they perceived multilingualism, with their differences leading to distinctive country clusters. Gender and education level (elementary vs. secondary) differences were also observed irrespective of country. These findings enhance our understanding of the role that the characteristics of teachers and their classrooms play in a multilingual setting across diverse European settings. The practical relevance of the results and new opportunities for teacher training are discussed
Mid-IR and VUV spectroscopic characterisation of thermally processed and electron irradiated CO2 astrophysical ice analogues
Attenuation of visual evoked responses to hand and saccade-initiated flashes
Sensory attenuation refers to reduced brain responses to self-initiated sensations relative to those produced by the external world. It is a low-level process that may be linked to higher-level cognitive tasks such as reality monitoring. The phenomenon is often explained by prediction error mechanisms of universal applicability to sensory modality; however, it is most widely reported for auditory stimuli resulting from self-initiated hand movements. The present series of event-related potential (ERP) experiments explored the generalizability of sensory attenuation to the visual domain by exposing participants to flashes initiated by either their own button press or volitional saccade and comparing these conditions to identical, computer-initiated stimuli. The key results showed that the largest reduction of anterior visual N1 amplitude occurred for saccade-initiated flashes, while button press-initiated flashes evoked an intermediary response between the saccade-initiated and externally initiated conditions. This indicates that sensory attenuation occurs for visual stimuli and suggests that the degree of electrophysiological attenuation may relate to the causal likelihood of pairings between the type of motor action and the modality of its sensory response
Thirty loci identified for heart rate response to exercise and recovery implicate autonomic nervous system.
Impaired capacity to increase heart rate (HR) during exercise (ΔHRex), and a reduced rate of recovery post-exercise (ΔHRrec) are associated with higher cardiovascular mortality rates. Currently, the genetic basis of both phenotypes remains to be elucidated. We conduct genome-wide association studies (GWASs) for ΔHRex and ΔHRrec in ~40,000 individuals, followed by replication in ~27,000 independent samples, all from UK Biobank. Six and seven single-nucleotide polymorphisms for ΔHRex and ΔHRrec, respectively, formally replicate. In a full data set GWAS, eight further loci for ΔHRex and nine for ΔHRrec are genome-wide significant (P ≤ 5 × 10-8). In total, 30 loci are discovered, 8 being common across traits. Processes of neural development and modulation of adrenergic activity by the autonomic nervous system are enriched in these results. Our findings reinforce current understanding of HR response to exercise and recovery and could guide future studies evaluating its contribution to cardiovascular risk prediction.This research has been conducted using the UK Biobank Resource (application 8256—Understanding genetic influences in the response of the cardiac electrical system to exercise) and is supported by Medical Research Council grant MR/N025083/1. We also wish to acknowledge the support of the NIHR Cardiovascular Biomedical Research Centre at Barts and Queen Mary University of London, UK. J.R. acknowledges support from the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement no. 608765. P.D.L. acknowledges support from the UCLH Biomedicine NIHR, Barts Heart Centre BRC. M.O. is supported by an IEF 2013 Marie Curie fellowship. B.M. holds an MRC eMedLab Medical Bioinformatics Career Development Fellowship, funded from award MR/L016311/1. This project was enabled through access to the MRC eMedLab Medical Bioinformatics infrastructure, award MR/L016311/1
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