297 research outputs found
The Role of Morphosyntactic Awareness in Conventional Lexical Segmentation
Starting with the alphabetic stage of writing acquisition, the learner struggles with issues related to spelling, including the segmentation of writing in graphic words. This study examined the conventional segmentation of words and its relation to morphosyntactic awareness in a sample of students in the 4th and 5th years of elementary education in public schools. Results reveal a discrepancy between the oral identification of words and performance in the segmentation of writing, with three criteria being used by students to define âwordâ: (1st) full meaning; (2nd) sequence of letters, not only one or two; (3rd) frequency of word use. Statistical analyses revealed significant positive correlations between conventional segmentation and morphosyntactic awareness. It is inferred that morphosyntactic skills support the establishment of the conventional notion of the word, and it is suggested that teachers promote the development of these skills, in order to ensure a greater command of the written language
Gene expression changes and community turnover differentially shape the global ocean metatranscriptome
Ocean microbial communities strongly influence the biogeochemistry, food webs, and climate of our planet. Despite recent advances in understanding their taxonomic and genomic compositions, little is known about how their transcriptomes vary globally. Here, we present a dataset of 187 metatranscriptomes and 370 metagenomes from 126 globally distributed sampling stations and establish a resource of 47 million genes to study community-level transcriptomes across depth layers from pole-to-pole. We examine gene expression changes and community turnover as the underlying mechanisms shaping community transcriptomes along these axes of environmental variation and show how their individual contributions differ for multiple biogeochemically relevant processes. Furthermore, we find the relative contribution of gene expression changes to be significantly lower in polar than in non-polar waters and hypothesize that in polar regions, alterations in community activity in response to ocean warming will be driven more strongly by changes in organismal composition than by gene regulatory mechanisms
Directional electrodes in deep brain stimulation: results of a survey by the European Association of Neurosurgical Societies (EANS)
Introduction
Directional Leads (dLeads) represent a new technical tool in Deep Brain Stimulation (DBS), and a rapidly growing population of patients receive dLeads.
Research question
The European Association of Neurosurgical Societies(EANS) functional neurosurgery Task Force on dLeads conducted a survey of DBS specialists in Europe to evaluate their use, applications, advantages, and disadvantages.
Material and methods
EANS functional neurosurgery and European Society for Stereotactic and Functional Neurosurgery (ESSFN) members were asked to complete an online survey with 50 multiple-choice and open questions on their use of dLeads in clinical practice.
Results
Forty-nine respondents from 16 countries participated in the survey (nâŻ=âŻ38 neurosurgeons, nâŻ=âŻ8 neurologists, nâŻ=âŻ3 DBS nurses). Five had not used dLeads. All users reported that dLeads provided an advantage (nâŻ=âŻ23 minor, nâŻ=âŻ21 major). Most surgeons (nâŻ=âŻ35) stated that trajectory planning does not differ when implanting dLeads or conventional leads. Most respondents selected dLeads for the ability to optimize stimulation parameters (nâŻ=âŻ41). However, the majority (nâŻ=âŻ24), regarded time-consuming programming as the main disadvantage of this technology. Innovations that were highly valued by most participants included full 3T MRI compatibility, remote programming, and closed loop technology.
Discussion and conclusion
Directional leads are widely used by European DBS specialists. Despite challenges with programming time, users report that dLeads have had a positive impact and maintain an optimistic view of future technological advances
Extensive Conserved Synteny of Genes between the Karyotypes of Manduca sexta and Bombyx mori Revealed by BAC-FISH Mapping
BACKGROUND: Genome sequencing projects have been completed for several species representing four highly diverged holometabolous insect orders, Diptera, Hymenoptera, Coleoptera, and Lepidoptera. The striking evolutionary diversity of insects argues a need for efficient methods to apply genome information from such models to genetically uncharacterized species. Constructing conserved synteny maps plays a crucial role in this task. Here, we demonstrate the use of fluorescence in situ hybridization with bacterial artificial chromosome probes as a powerful tool for physical mapping of genes and comparative genome analysis in Lepidoptera, which have numerous and morphologically uniform holokinetic chromosomes. METHODOLOGY/PRINCIPAL FINDINGS: We isolated 214 clones containing 159 orthologs of well conserved single-copy genes of a sequenced lepidopteran model, the silkworm, Bombyx mori, from a BAC library of a sphingid with an unexplored genome, the tobacco hornworm, Manduca sexta. We then constructed a BAC-FISH karyotype identifying all 28 chromosomes of M. sexta by mapping 124 loci using the corresponding BAC clones. BAC probes from three M. sexta chromosomes also generated clear signals on the corresponding chromosomes of the convolvulus hawk moth, Agrius convolvuli, which belongs to the same subfamily, Sphinginae, as M. sexta. CONCLUSIONS/SIGNIFICANCE: Comparison of the M. sexta BAC physical map with the linkage map and genome sequence of B. mori pointed to extensive conserved synteny including conserved gene order in most chromosomes. Only a few rearrangements, including three inversions, three translocations, and two fission/fusion events were estimated to have occurred after the divergence of Bombycidae and Sphingidae. These results add to accumulating evidence for the stability of lepidopteran genomes. Generating signals on A. convolvuli chromosomes using heterologous M. sexta probes demonstrated that BAC-FISH with orthologous sequences can be used for karyotyping a wide range of related and genetically uncharacterized species, significantly extending the ability to develop synteny maps for comparative and functional genomics
Incidence and prognostic value of tumour cells detected by RTâPCR in peripheral blood stem cell collections from patients with Ewing tumour
To retrospectively evaluate the incidence of tumour cell contamination of peripheral blood stem cell (PBSC) collections and to correlate these data with the clinical outcome after high-dose chemotherapy (HDCT) with stem cell rescue in patients with a high-risk Ewing tumour. Peripheral blood stem cell collections obtained from 171 patients were analysed. Tumour contamination was assessed by reverse transcriptaseâpolymerase chain reaction (RTâPCR). The files of 88 patients who underwent HDCT followed by PBSC reinfusion were reviewed in detail, and their outcome compared to the PBSC RTâPCR results. Seven of 88 PBSC collections (8%) contained tumour cells as detected by RTâPCR. Peripheral blood stem cells were collected after a median of five cycles of chemotherapy. No clinical factor predictive of tumour cell contamination of PBSC harvest could be identified. Event-free survival (EFS) and overall survival (OS) of the whole study population were 45.3 % and 51.8 % at 3 years from the date of the graft, respectively. Forty-five patients relapsed with a median time of 15 months after graft, only four of whom had tumour cell contamination of the PBSC harvest. Tumour cell contamination of PBSC collection is rare and does not seem to be associated with a significantly poorer EFS or OS in this high-risk population
The genetic architecture of a host shift: An adaptive walk protected an aphid and its endosymbiont from plant chemical defenses
This is the final version. Available from American Association for the Advancement of Science via the DOI in this record.âŻThe RNA and DNA sequence data generated in this study have been deposited with NCBI under accession number PRJNA574571. The sequence of RPS11/ADAMTS9 has been deposited under NCBI accession number MF1555663, and the accession numbers of other genes characterized in this study can be found in data file S1. All other data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. Additional data related to this paper may be requested from the authors.Host shifts can lead to ecological speciation and the emergence of new pests and pathogens. However, the mutational events that facilitate the exploitation of novel hosts are poorly understood. Here, we characterize an adaptive walk underpinning the host shift of the aphid Myzus persicae to tobacco, including evolution of mechanisms that overcame tobacco chemical defenses. A series of mutational events added as many as 1.5 million nucleotides to the genome of the tobacco-adapted subspecies, M. p. nicotianae, and yielded profound increases in expression of an enzyme that efficiently detoxifies nicotine, both in aphid gut tissue and in the bacteriocytes housing the obligate aphid symbiont Buchnera aphidicola. This dual evolutionary solution overcame the challenge of preserving fitness of a mutualistic symbiosis during adaptation to a toxic novel host. Our results reveal the intricate processes by which genetic novelty can arise and drive the evolution of key innovations required for ecological adaptation.European Union Horizon 2020Czech Science FoundationCzech Science FoundationEuropean Social Fund and the state budget of the Czech RepublicBiotechnology and Biological Sciences Research Council (BBSRC
Epilepsy, hippocampal sclerosis and febrile seizures linked by common genetic variation around SCN1A
Epilepsy comprises several syndromes, amongst the most common being mesial temporal lobe epilepsy with hippocampal sclerosis. Seizures in mesial temporal lobe epilepsy with hippocampal sclerosis are typically drug-resistant, and mesial temporal lobe epilepsy with hippocampal sclerosis is frequently associated with important co-morbidities, mandating the search for better understanding and treatment. The cause of mesial temporal lobe epilepsy with hippocampal sclerosis is unknown, but there is an association with childhood febrile seizures. Several rarer epilepsies featuring febrile seizures are caused by mutations in SCN1A, which encodes a brain-expressed sodium channel subunit targeted by many anti-epileptic drugs. We undertook a genome-wide association study in 1018 people with mesial temporal lobe epilepsy with hippocampal sclerosis and 7552 control subjects, with validation in an independent sample set comprising 959 people with mesial temporal lobe epilepsy with hippocampal sclerosis and 3591 control subjects. To dissect out variants related to a history of febrile seizures, we tested cases with mesial temporal lobe epilepsy with hippocampal sclerosis with (overall n = 757) and without (overall n = 803) a history of febrile seizures. Meta-analysis revealed a genome-wide significant association for mesial temporal lobe epilepsy with hippocampal sclerosis with febrile seizures at the sodium channel gene cluster on chromosome 2q24.3 [rs7587026, within an intron of the SCN1A gene, P = 3.36 Ă 10â9, odds ratio (A) = 1.42, 95% confidence interval: 1.26-1.59]. In a cohort of 172 individuals with febrile seizures, who did not develop epilepsy during prospective follow-up to age 13 years, and 6456 controls, no association was found for rs7587026 and febrile seizures. These findings suggest SCN1A involvement in a common epilepsy syndrome, give new direction to biological understanding of mesial temporal lobe epilepsy with hippocampal sclerosis with febrile seizures, and open avenues for investigation of prognostic factors and possible prevention of epilepsy in some children with febrile seizure
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