Fucose Sensing Regulates Bacterial Intestinal Colonization

The mammalian gastrointestinal (GI) tract provides a complex and competitive environment for the microbiota1. Successful colonization by pathogens depends on scavenging nutrients, sensing chemical signals, competing with the resident bacteria, and precisely regulating expression of virulence genes2. The GI pathogen enterohemorrhagic E.coli (EHEC) relies on inter-kingdom chemical sensing systems to regulate virulence gene expression3–4. Here we show that these systems control the expression of a novel two-component signal transduction system, named FusKR, where FusK is the histidine sensor kinase (HK), and FusR the response regulator (RR). FusK senses fucose and controls expression of virulence and metabolic genes. This fucose-sensing system is required for robust EHEC colonization of the mammalian intestine. Fucose is highly abundant in the intestine5. Bacteroides thetaiotaomicron (B.theta) produces multiple fucosidases that cleave fucose from host glycans, resulting in high fucose availability in the gut lumen6. During growth in mucin, B.theta contributes to EHEC virulence by cleaving fucose from mucin, thereby activating the FusKR signaling cascade, modulating EHEC’s virulence gene expression. Our findings suggest that EHEC uses fucose, a host-derived signal made available by the microbiota, to modulate EHEC pathogenicity and metabolism

MOVIMENTOS SOCIAIS, PROTAGONISMO DE MULHERES E A LUTA CONTRA A FOME NA PANDEMIA DE COVID-19

This work deals with the activisms around the struggles for cash transfer and the fight against hunger during the Covid-19 pandemic in Brazil, between 2020 and 2021. We investigated the strategies used by activists to obtain emergency income and to operate solidarity brigades to fight hunger. We analyzed the actions of social movements, especially in the "Basic Income We Want" campaign. For our analysis, we conducted interviews and examined documents from social movements and government research institutes. Our hypothesis is that the authoritarian political context of the Bolsonaro government, as well as the country's deep economic and social crisis, has driven social movements of multiple origins and traditions to unite around the fight against deep social injustice in Brazil. As a result, we observed that the struggles for cash transfer and the fight against hunger in the Covid-19 pandemic in Brazil articulated a significant confrontation with the authoritarian Bolsonaro government.Este trabalho trata dos ativismos em torno das lutas por transferência de renda e de combate à fome na pandemia da Covid-19 no Brasil, entre 2020 e 2021. Investigamos as estratégias utilizadas por ativistas para a conquista da renda emergencial e para o funcionamento de brigadas de solidariedade de combate à fome. Analisamos a ação dos movimentos sociais, em especial na campanha “Renda Básica que Queremos”. Para nossa análise, realizamos entrevistas e examinamos documentos dos movimentos sociais e de institutos de pesquisa governamental. A nossa hipótese é que o contexto político autoritário do governo Bolsonaro, assim como a profunda crise econômica e social do país, impulsionou movimentos sociais de origens e tradições diversificadas a se unirem em torno do combate à profunda injustiça social no Brasil. Como resultado, observamos que as lutas por transferência de renda e combate à fome na pandemia da Covid-19 no Brasil articularam um afrontamento significativo ao autoritário governo Bolsonaro

Birds, montane forest, state of Rio de Janeiro, Southeastern Brazil

Field surveys in montane Atlantic forest of Rio de Janeiro state, Brazil, provided a list of 82 bird species in four sites visited. Our protocol relied on standardized use of mist nets and observations. The birds recorded include 40 Atlantic forest endemics, three globally and two nationally Vulnerable species, and two regionally Endangered species. Data on species elevation are included and discussed. This work enhances baseline knowledge of these species to assist future studies in these poorly understood, but biologically important areas

Strain Engineering a 4a×3a4a\times\sqrt{3}a Charge Density Wave Phase in Transition Metal Dichalcogenide 1T-VSe2_2

We report a rectangular charge density wave (CDW) phase in strained 1T-VSe$_2$ thin films synthesized by molecular beam epitaxy on c-sapphire substrates. The observed CDW structure exhibits an unconventional rectangular 4a{\times}{\sqrt{3a}} periodicity, as opposed to the previously reported hexagonal $4a\times4a$ structure in bulk crystals and exfoliated thin layered samples. Tunneling spectroscopy shows a strong modulation of the local density of states of the same $4a\times\sqrt{3}a$ CDW periodicity and an energy gap of $2\Delta_{CDW}=(9.1\pm0.1)$ meV. The CDW energy gap evolves into a full gap at temperatures below 500 mK, indicating a transition to an insulating phase at ultra-low temperatures. First-principles calculations confirm the stability of both $4a\times4a$ and $4a\times\sqrt{3}a$ structures arising from soft modes in the phonon dispersion. The unconventional structure becomes preferred in the presence of strain, in agreement with experimental findings

User requirements for national research and education networks for research in West and Central Africa

National research and education networks (NRENs) play a critical role in the development of communication network infrastructure and networked services for researchers and educators. They help close ‘digital divides’ between and within countries and are an essential factor for national and international development. In collaboration with the West and Central African Research and Education Network (WACREN), the TANDEM project has developed a roadmap for the development of NRENs in the region. This was based on the results of a survey that was conducted to investigate user requirements of networked services. The analysis of the 561 responses to a three-part questionnaire divided into 11 education, 22 research and 2 technical management questions identified key educational and research service needs. This article reports on the results of the survey with respect to research services. Highlights include respondents wanting regular access to online conference and academic articles (89%), a range of research services including online library resources, video conferencing, collaboration tools, online data access and storage, online library resources and inter-university login (>87%), access to remote computing facilities (80%) and high performance computing facilities (77%). A desire to share data with others online (74%) was also identified. Respondents also indicated that they would like to access research services through a range of device types–Laptops (96%), Fixed PC (86%) and Mobile Devices (81%). Poor network connectivity was consistently identified as being a major barrier to research in the region.H2020 TransAfrican Network Development (TANDEM) and the H2020 Energising Scientific Endeavou

Association between diabetes and cognitive function at baseline in the Brazilian Longitudinal Study of Adult Health (ELSA- Brasil)

Diabetes has been associated with cognitive changes and an increased risk of vascular dementia and Alzheimer’s disease, but it is unclear whether there are associations between diabetes and early alterations in cognitive performance. The present study consisted of a cross-section analysis of 14,444 participants aged 35–74 years and from a developing country at baseline in the Brazilian Longitudinal Study of Adult Health (ELSA–Brasil); these participants were recruited between 2008 and 2010. We investigated whether there was an association between diabetes and early changes in the cognitive performance of this Brazilian population. To assess cognitive domains, we used the word-list learning, word-list delayed recall and word recognition tests along. Phonemic verbal fuency tests included semantic phonemic test (animals) and a phonemic test (words beginning with the letter F). Executive functions associated with attention, concentration and psychomotor speed were evaluated using the Trail Making Test B. The exposure variable in the study was defned as diabetes. Multiple linear regression was used to estimate the association between diabetes and cognitive performance. The results were adjusted for age, sex, education, hypertension, coronary disease, depression, physical activity, smoking, alcohol consumption, and the cholesterol/HDL-C ratio. We found a signifcant association between diabetes and decreased memory, language and executive function (attention, concentration and psychomotor speed) performance in this population from a country with a distinct epidemiological profle, even after adjusting for the main intervening variables

Genetic Ablation of the Isoform γ of PI3K Decreases Antidepressant Efficacy of Ketamine in Male Mice

About one-third of major depressive disorder (MDD) patients demonstrate unresponsiveness to classic antidepressants, and even the clinical efficacy of fast-acting drugs such as ketamine varies significantly among patients with treatment-resistant depression. Nevertheless, the lack of suitable animal models that mimic a possible ketamine-resistant phenotype challenges the understanding of resistance to drug treatment. In this study, we showed that PI3Kγ knock-out (KO) mice do not respond to classical doses of ketamine and classical antidepressants. PI3Kγ KO mice were unresponsive to both the rapid and sustained antidepressant-like effects of a single dose of ketamine in the forced swimming test. Additionally, they were unresponsive to the antidepressant-like effects induced by the tricyclic antidepressant imipramine and the selective serotonin reuptake inhibitor fluoxetine. However, acute pharmacological inhibition of PI3Kγ did not block the antidepressant-like effect of ketamine, showing that a chronic deficiency of the PI3Kγ-mediated pathway is necessary for the effects of classic doses of ketamine and antidepressants. Therefore, we propose that PI3Kγ participates in the antidepressant activity and is likely implicated in the neurobiology and phenotype observed in patients with MDD who demonstrate treatment resistance

CRISPR Screen Reveals that EHEC’s T3SS and Shiga Toxin Rely on Shared Host Factors for Infection

ABSTRACT Enterohemorrhagic Escherichia coli (EHEC) has two critical virulence factors—a type III secretion system (T3SS) and Shiga toxins (Stxs)—that are required for the pathogen to colonize the intestine and cause diarrheal disease. Here, we carried out a genome-wide CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats with Cas9) loss-of-function screen to identify host loci that facilitate EHEC infection of intestinal epithelial cells. Many of the guide RNAs identified targeted loci known to be associated with sphingolipid biosynthesis, particularly for production of globotriaosylceramide (Gb3), the Stx receptor. Two loci (TM9SF2 and LAPTM4A) with largely unknown functions were also targeted. Mutations in these loci not only rescued cells from Stx-mediated cell death, but also prevented cytotoxicity associated with the EHEC T3SS. These mutations interfered with early events associated with T3SS and Stx pathogenicity, markedly reducing entry of T3SS effectors into host cells and binding of Stx. The convergence of Stx and T3SS onto overlapping host targets provides guidance for design of new host-directed therapeutic agents to counter EHEC infection