240 research outputs found
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
How experimental physiology and ecological niche modelling can inform the management of marine bioinvasions?
Marine bioinvasions are increasing worldwide by a number of factors related to the anthroposphere, such as higher ship traffic, climate change and biotic communities' alterations. Generating information about species with high invasive potential is necessary to inform management decisions aiming to prevent their arrival and spread. Grateloupia turuturu, one of the most harmful invasive macroalgae, is capable of damaging ecosystem functions and services, and causing biodiversity loss. Here we developed an ecological niche model using occurrence and environmental data to infer the potential global distribution of G. turuturu. In addition, ecophysiological experiments were performed with G. turuturu populations from different climatic regions to test predictions regarding invasion risk. Our model results show high suitability in temperate and warm temperate regions around the world, with special highlight to some areas where this species still doesn't occur. Thalli representing a potential temperate region origin, were held at 10, 13, 16, 20 and 24 degrees C, and measurements of optimal quantum field (Fv/Fm) demonstrated a decrease of photosynthetic yield in the higher temperature. Thalli from the population already established in warm temperate South Atlantic were held at 18, 24 and 30 degrees C with high and low nutrient conditions. This material exposed to the higher temperature demonstrated a drop in photosynthetic yield and significant reduction of growth rate. The congregation of modelling and physiological approach corroborate the invasive potential of G. turuturu and indicate higher invasion risk in temperate zones. Further discussions regarding management initiatives must be fostered to mitigate anthropogenic transport and eventually promote eradication initiatives in source areas, with special focus in the South America. We propose that this combined approach can be used to assess the potential distribution and establishment of other marine invasive species. (C) 2019 Elsevier B.V. All rights reserved.National Council for Scientific and Technological Development (CNPq)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ)Sustainable prospection in ocean islands: biodiversity, chemistry, ecology and biotechnology (PROSPECMAR-Islands)Rede nacional de pesquisa em biodiversidade marinha (SISBIOTAMar)Foundation for the support of research and innovation in the State of Santa Catarina (FAPESC)Fundacao BoticarioCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Pew FoundationFoundation for Science and Technology (FCT) of PortugalPortuguese Foundation for Science and Technology [SFRH/BPD/111003/2015, CCMAR/Multi/04326/2013, DL57/2016/CP1361/CT0035]Centre Mondial d'Innovation, Roullier GroupCNPqConselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) [CSF 88888.884790/2014-00, 306917/2009-2]CAPESCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) [PNADB 2338000071/2010-61]Instituto Nacional de Ciencia e Tecnologia para as Mudancas no Clima (INCT-MC)info:eu-repo/semantics/publishedVersio
The Aspergillus fumigatus CrzA Transcription Factor Activates Chitin Synthase Gene Expression during the Caspofungin Paradoxical Effect
This is the final version. Available from American Society for Microbiology via the DOI in this record. Aspergillus fumigatus is an opportunistic fungal pathogen that causes
invasive aspergillosis (IA), a life-threatening disease in immunocompromised humans.
The echinocandin caspofungin, adopted as a second-line therapy in combating IA, is
a -1,3-glucan synthase inhibitor, which, when used in high concentrations, reverts
the anticipated A. fumigatus growth inhibition, a phenomenon called the “caspofungin
paradoxical effect” (CPE). The CPE has been widely associated with increased chitin
content in the cell wall due to a compensatory upregulation of chitin synthaseencoding
genes. Here, we demonstrate that the CPE is dependent on the cell wall
integrity (CWI) mitogen-activated protein kinase MpkAMPK1 and its associated transcription
factor (TF) RlmARLM1, which regulate chitin synthase gene expression in response
to different concentrations of caspofungin. Furthermore, the calcium- and
calcineurin-dependent TF CrzA binds to and regulates the expression of specific chitin
synthase genes during the CPE. These results suggest that the regulation of cell
wall biosynthetic genes occurs by several cellular signaling pathways. In addition,
CrzA is also involved in cell wall organization in the absence of caspofungin. Differences
in the CPE were also observed between two A. fumigatus clinical isolates,
which led to the identification of a novel basic leucine zipper TF, termed ZipD. This
TF functions in the calcium-calcineurin pathway and is involved in the regulation of
cell wall biosynthesis genes. This study therefore unraveled additional mechanisms
and novel factors governing the CPE response, which ultimately could aid in developing
more effective antifungal therapies.CNPqFAPES
The Aspergillus fumigatus transcription factor RglT is important for gliotoxin biosynthesis and self-protection, and virulence
This is the final version (corrected proof). The final published version is available from Public Library of Science via the DOI in this recordData Availability: Short reads were submitted to the NCBI’s Sequence Read Archive under accession number SRP154617 (https://www.ncbi.nlm.nih.gov/sra/?term=SRP154617). The ChIPseq data are available from NCBI SRA (sequence read archive) database under accession number PRJNA574873 (https://www.ncbi.nlm.nih.gov/Traces/study/?acc=PRJNA574873&o=acc_s%3Aa).Aspergillus fumigatus is an opportunistic fungal pathogen that secretes an array of immune-modulatory molecules, including secondary metabolites (SMs), which contribute to enhancing fungal fitness and growth within the mammalian host. Gliotoxin (GT) is a SM that interferes with the function and recruitment of innate immune cells, which are essential for eliminating A. fumigatus during invasive infections. We identified a C6 Zn cluster-type transcription factor (TF), subsequently named RglT, important for A. fumigatus oxidative stress resistance, GT biosynthesis and self-protection. RglT regulates the expression of several gli genes of the GT biosynthetic gene cluster, including the oxidoreductase-encoding gene gliT, by directly binding to their respective promoter regions. Subsequently, RglT was shown to be important for virulence in a chemotherapeutic murine model of invasive pulmonary aspergillosis (IPA). Homologues of RglT and GliT are present in eurotiomycete and sordariomycete fungi, including the non-GT-producing fungus A. nidulans, where a conservation of function was described. Phylogenetically informed model testing led to an evolutionary scenario in which the GliT-based resistance mechanism is ancestral and RglT-mediated regulation of GliT occurred subsequently. In conclusion, this work describes the function of a previously uncharacterised TF in oxidative stress resistance, GT biosynthesis and self-protection in both GT-producing and non-producing Aspergillus species.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESPConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES)Wellcome TrustUniversity of MacauNational Science Foundation (NSF)Vanderbilt UniversityHoward Hughes Medical Institut
Teamwork in a coronary care unit: facilitating and hindering aspects
Abstract OBJECTIVE To identify, within a multidisciplinary team, the facilitating and hindering aspects for teamwork in a coronary care unit. METHOD A descriptive study, with qualitative and quantitative data, was carried out in the coronary care unit of a public hospital. The study population consisted of professionals working in the unit for at least one year. Those who were on leave or who were not located were excluded. The critical incident technique was used for data collection, by means of semi-structured interviews. For data analysis, content analysis and the critical incident technique were applied. RESULTS Participants were 45 professionals: 29 nursing professionals; 11 physicians; 4 physical therapists; and 1 psychologist. A total of 49 situations (77.6% with negative references); 385 behaviors (54.2% with positive references); and 182 consequences emerged (71.9% with negative references). Positive references facilitate teamwork, whereas negative references hinder it. A collaborative/communicative interprofessional relationship was evidenced as a facilitator; whereas poor collaboration among agents/inadequate management was a hindering aspect. CONCLUSION Despite the prevalence of negative situations and consequences, the emphasis on positive behaviors reveals the efforts the agents make in order to overcome obstacles and carry out teamwork
Glacial vicariance drives phylogeographic diversification in the amphi-boreal kelp Saccharina latissima
Glacial vicariance is regarded as one of the most prevalent drivers of phylogeographic structure and speciation among high-latitude organisms, but direct links between ice advances and range fragmentation have been more difficult to establish in marine than in terrestrial systems. Here we investigate the evolution of largely disjunct (and potentially reproductively isolated) phylogeographic lineages within the amphi-boreal kelp Saccharina latissima s.l. Using molecular data (COI, microsatellites) we confirm that S. latissima comprises also the NE Pacific S. cichorioides complex and is composed of divergent lineages with limited range overlap and genetic admixture. Only a few genetic hybrids were detected throughout a Canadian Arctic/NW Greenland contact zone. The degree of genetic differentiation and sympatric isolation of phylogroups suggest that S. latissima s.l. represents a complex of incipient species. Phylogroup distributions compared with paleo-environmental reconstructions of the cryosphere further suggest that diversification within S. latissima results from chronic glacial isolation in disjunct persistence areas intercalated with ephemeral interglacial poleward expansions and admixture at high-latitude (Arctic) contact zones. This study thus supports a role for glaciations not just in redistributing pre-existing marine lineages but also as a speciation pump across multi-glacial cycles for marine organisms otherwise exhibiting cosmopolite amphi-boreal distributions.Pew Foundation (USA); Portuguese FCT (Fundacao para a Ciencia e a Tecnologia) through program GENEKELP [PTDC/MAR-EST/6053/2014]; Portuguese FCT (Fundacao para a Ciencia e a Tecnologia) through program MARFOR [Biodiversa/0004/2015]; Portuguese FCT (Fundacao para a Ciencia e a Tecnologia) [UID/Multi/04326/2013, SFRH/BPD/88935/2012, SFRH/BPD/111003/2015]; NSERC; FRQNT; Canada Foundation for Innovation; New Brunswick Innovation Foundation; European Union's Seventh Framework Programme [226248]; Danish Environmental Protection Agency within the Danish Cooperation for Environment in the Arctic (DANCEA)info:eu-repo/semantics/publishedVersio
Phosphorus Fertilization Increases Biomass and Nutrient Accumulation Under Improved Fallow Management in a Slash-and-Mulch System in Eastern Amazonia, Brazil
Vineyard microclimate and yield under different plastic covers.
The use of plastic cover in vineyards minimizes effects of adverse weather conditions. The northwest of São Paulo State is one of the largest grape producing regions in Brazil; however, few studies investigate the effects of different plastic covers on vineyards in this region. This study compared the effect of black shading screen (BSS) and braided polypropylene film (BPF) on BRS Morena vineyard microclimate, grown on an overhead trellis system in the northwestern São Paulo. The experiments were carried out during three growing seasons (2012 ? 2014). BSS allowed superior incoming solar radiation (SR) transmissivity, resulting in higher net radiation (Rn), and higher ratio between photosynthetically active (PAR) and SR. No differences were observed between the average air temperatures (T) and relative humidity (RH) of covered environments (BPF and BSS) and outside condition (automatic weather station ? AWS), due to high air circulation, despite wind speed (WS) reduction caused by plastic covers. BPF provided better conditions for vineyard growth with higher fruit yield than vineyard under BSS regarding the number of shoots with bunches per plant, bunch and stem weights, longitudinal diameter of berries, quantity of fertile buds per shoot, and yield per shoot and per plant. BPF covers also influenced leaf size and growth speed of plants in vineyards. Keywords Black shading screen . Braided polypropylene film . BRS Morena . Leaf wetness duration . Yiel
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