79 research outputs found
The impact of early and late literacy on the functional connectivity of vision and
Introduction: Learning to read leads to functional and structural changes in the cortical regions related to
vision and language. The visual word-form area (VWFA) is though to play a key role in the interaction between
these two systems (Dehaene et al. 2015). For instance, the VWFA is activated not only from bottom-up during
reading but also in a top-down manner during speech listening without visual stimulation (Dehaene et al. 2010).
The objective of this study was twofolded: how literacy acquisition affects four intrinsic functional connectivity
networks related to vision and language (a dorsal language [DLN], a bilateral auditory [AN], a low-level
[LLVN] and a high-level visual [HLVN] networks); and to explore the role of the VWFA as an interface between
high-level vision and language functions.
Methods: Independent component analysis (ICA) was applied to functional magnetic resonance imaging data
from 40 adult participants with variable levels of literacy (illiterate, late literate and early literate). The four
functional connectivity networks were compared across groups using dual-regression (Filippini et al. 2009). In
addition, we directly explored the functional connectivity between the VWFA and each of the studied networks.
Finally, the strengh of connectivity between the VWFA and each network was compared across groups and
correlated with individual reading fluency scores.
Results: ICA produced 40 networks, and spatial crosscorrelation was used to identify the four networks of
interest. Literacy was positively correlated with increased connectivity within the four networks. A major
difference separating early literate from illiterate and late literate subjects was found. The connectivity between
the VWFA and the DLN increased with literacy. Conversely, the strength of connectivity between the VWFA and
the HLVN correlated negatively with literacy. Finally, , the HLVN-VWFA connectivity was negatively correlated
with reading scores while the connectivity between the DLN-VWFA was positively correlated with reading
scores.
Discussion:Literacy has a strong influence on the visual and language functional networks. Literacy modifies
the VWFA connectivity, by making it functionally closer to the language system, and more distinct from other
associative visual areas that do not contribute to the reading process. The current results suggest that early
acquisition of literacy plays a critical role for the tuning of the functional brain architecture.
References: -Dehaene S et al. Nat Rev Neurosci.(2015)16:234 244
-Dehaene S et al. Science.(2010)330:1359â1364
-Filippini N et al. PNAS.(2009)106, 7209â7214Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
Unraveling and exploitation of diversity for resistance to Mycosphaerella graminicola and Fusarium graminearum in wheat and its progenitors
La fusariose et la septoriose sont deux maladies trĂšs dommageables (chute de rendement, toxicitĂ©) pour le blĂ©. Il est important d'identifier de nouvelles sources de rĂ©sistance efficaces contre des isolats de septoriose trĂšs virulents et contre la fusariose Fusarium graminearum (majoritairement prĂ©sente en France). Ainsi, ce projet nous a permis d'identifier de nouvelles sources de rĂ©sistance Ă la fusariose et Ă la septoriose. Parmi celles-ci, les plus intĂ©ressantes ont Ă©tĂ© retenues pour ĂȘtre les parents de nouvelles populations (HD) d'Ă©tude. ParallĂšlement, une population de 235 lignĂ©es HD Apache/Balance (ApBa) a Ă©tĂ© Ă©tudiĂ©e pour identifier des QTL de rĂ©sistance Ă la fusariose qui offrent la possibilitĂ© au sĂ©lectionneur d'identifier plus efficacement, dans leur matĂ©riel, les caractĂšres de rĂ©sistance issus d'Apach
The pandemic toll and post-acute sequelae of SARS-CoV-2 in healthcare workers at a Swiss University Hospital.
Healthcare workers have potentially been among the most exposed to SARS-CoV-2 infection as well as the deleterious toll of the pandemic. This study has the objective to differentiate the pandemic toll from post-acute sequelae of SARS-CoV-2 infection in healthcare workers compared to the general population. The study was conducted between April and July 2021 at the Geneva University Hospitals, Switzerland. Eligible participants were all tested staff, and outpatient individuals tested for SARS-CoV-2 at the same hospital. The primary outcome was the prevalence of symptoms in healthcare workers compared to the general population, with measures of COVID-related symptoms and functional impairment, using prevalence estimates and multivariable logistic regression models. Healthcare workers (n=3,083) suffered mostly from fatigue (25.5%), headache (10.0%), difficulty concentrating (7.9%), exhaustion/burnout (7.1%), insomnia (6.2%), myalgia (6.7%) and arthralgia (6.3%). Regardless of SARS-CoV-2 infection, all symptoms were significantly higher in healthcare workers than the general population (n=3,556). SARS-CoV-2 infection in healthcare workers was associated with loss or change in smell, loss or change in taste, palpitations, dyspnea, difficulty concentrating, fatigue, and headache. Functional impairment was more significant in healthcare workers compared to the general population (aOR 2.28; 1.76-2.96), with a positive association with SARS-CoV-2 infection (aOR 3.81; 2.59-5.60). Symptoms and functional impairment in healthcare workers were increased compared to the general population, and potentially related to the pandemic toll as well as post-acute sequelae of SARS-CoV-2 infection. These findings are of concern, considering the essential role of healthcare workers in caring for all patients including and beyond COVID-19
COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study
Background:
The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms.
Methods:
International, prospective observational study of 60â109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms.
Results:
âTypicalâ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (â€â18 years: 69, 48, 23; 85%), older adults (â„â70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each Pâ<â0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country.
Interpretation:
This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men
Concise synthesis of di- and trisaccharides related to the O-antigens from Shigella flexneri serotypes 6 and 6a, based on late stage mono-O-acetylation and/or site-selective oxidation
International audienceShigella flexneri serotypes 6 and 6a are closely related bacteria causing shigellosis in humans. Their O-antigens are {â4)-ÎČ-d-GalpA-(1â3)-ÎČ-d-GalpNAc-(1â2)-[3Ac/4Ac]-α-l-Rhap-(1â2)-α-l-Rhap-(1â}n acidic polysaccharides ({ABAcCD}n), which only differ in the degree of O-acetylation. A concise synthesis of two disaccharides (BC, BAcC) and four trisaccharides, representing portions and/or analogs of the O-antigens, is described. A protected intermediate compatible with late stage 3C-O-acetylation, and/or galactosyl (A°) to galacturonic acid (A) conversion, was designed and assembled from trichloroacetimidate and thioglycoside donors tuned for high yielding glycosylation and excellent stereocontrol. The galacturonic moiety was efficiently introduced from galactose using a TEMPO/NaOCl/NaClO2-based oxidation protocol optimized for full compatibility with sensitive moieties, such as allyl ethers and acetates. Final Pd/C-mediated deprotection provided the targets, including the propyl glycoside ABAcC, its non O-acetylated counterpart ABC, and the non acidic analogs A°BAcC and A°BC. The BC and ABC oligosaccharides are also portions of the O-antigen from Escherichia coli O147, which causes diarrhea in pigs
Preparation of synthetic glycoconjugates as potential vaccines against Shigella flexneri serotype 2a disease.
International audienceThe synthesis of three neoglycopeptides incorporating carbohydrate haptens, differing in length, covalently linked to a non natural universal T helper peptide is disclosed. They were synthesized according to a blockwise strategy based on the condensation of appropriate di-, tri-, and tetrasaccharide trichloroacetimidate donors onto an azidoethyl 2-acetamido-2-deoxybeta-D-glucopyranoside acceptor. Use of thiol-maleimide coupling chemistry allowed site-selective efficient conjugation
- âŠ