102 research outputs found
Whistle source levels of free-ranging beluga whales in Saguenay-St. Lawrence marine park
International audienceWild beluga whistle source levels (SLs) are estimated from 52 three-dimensional (3D) localized calls using a 4-hydrophone array. The probability distribution functions of the root-mean-square (rms) SL in the time domain, and the peak, the strongest 3-dB, and 10-dB SLs from the spectrogram, were non-Gaussian. The average rms SL was 143.8 +- 6.7 dB re 1microPa at 1m. SL spectral metrics were, respectively, 145.8 +- 8 dB, 143.2 +-7.1 dB, and 138.5 +-6.9 dB re 1 microPa. 1microPa / Hz at 1m
TAC-1, a Regulator of Microtubule Length in the C. elegans Embryo
AbstractRegulation of microtubule growth is critical for many cellular processes, including meiosis, mitosis, and nuclear migration. We carried out a genome-wide RNAi screen in Caenorhabditis elegans to identify genes required for pronuclear migration, one of the first events in embryogenesis requiring microtubules. Among these, we identified and characterized tac-1 a new member of the TACC (Transforming Acidic Coiled-Coil) family [1]. tac-1(RNAi) embryos exhibit very short microtubules nucleated from the centrosomes as well as short spindles. TAC-1 is initially enriched at the meiotic spindle poles and is later recruited to the sperm centrosome. TAC-1 localization at the centrosomes is regulated during the cell cycle, with high levels during mitosis and a reduction during interphase, and is dependent on aurora kinase 1 (AIR-1), a protein involved in centrosome maturation [2]. tac-1(RNAi) embryos resemble mutants of zyg-9[3], which encodes a previously characterized centrosomal protein of the XMAP215 family and was also found in our screen. We show that TAC-1 and ZYG-9 are dependent on one another for their localization at the centrosome, and this dependence suggests that they may function together as a complex. We conclude that TAC-1 is a major regulator of microtubule length in the C. elegans embryo
Transfluthrin indoor air concentration and inhalation exposure during application of electric vaporizers
International audienceDifferent household insecticide applications via two electric vaporizers emitting transfluthrin were realized in a full-scale experimental room under controlled air exchange rate conditions. On-line high-time resolved measurements of the gas-phase concentrations of the active substance during and immediately after the spreading periods were performed with a High Sensitivity Proton-Transfer-Reaction Mass Spectrometer (HS-PTR-MS). Experimental and modelled data from the ConsExpo 4.0 software were also compared to evaluate the sources of differences. Different application scenarios were also compared. Averaged inhaled concentrations over 1h, 1week, and 5months were estimated to be 8.3, 1.8, and 1.8ÎŒg.m(-3), respectively. Corresponding margins of exposures range from 1000 to 10,000, claiming for the absence of effect. Dermal and dust ingestion pathways, although roughly estimated, seems being non-negligible. This claims for a more in-depth integrated risk assessment
Involvement of fatty acid pathways and cortical interaction of the pronuclear complex in Caenorhabditis elegans embryonic polarity.
BACKGROUND: Cell polarity is essential for many decisions made during development. While investigation of polarity-specific factors has yielded great insights into the polarization process, little is known on how these polarity-specific factors link to the basic cellular mechanisms that function in non-polarity aspects of the cell. To better understand the mechanisms that establish embryonic polarity, we investigated genes required for polarity in the one-cell C. elegans embryo that are also required for other non-polarity functions. This has led to the identification of the Pod-class of mutants that are characterized by osmosensitive embryos and defects in anterior-posterior polarity. RESULTS: Mutation in either of two loci of this class, emb-8 and pod-2, disrupts embryonic polarization and results in osmotically-sensitive embryos. Loss of emb-8, a previously uncharacterized polarity gene, causes mislocalization of PAR-3 and PAR-2 that molecularly mark the anterior and posterior cortices. emb-8 encodes NADPH-cytochrome P450 reductase, a protein supplying electrons to cytochrome P450-family enzymes, some of which catalyze fatty acid modifications. Cloning of the previously characterized polarity gene pod-2 reveals it encodes acetyl-CoA carboxylase, an enzyme that catalyzes the first step in de novo fatty acid synthesis. Depletion of fatty acid synthase, the next enzyme in the biosynthetic pathway, by RNA-interference (RNAi) also causes similar loss of one-cell polarity. Furthermore, pod-2 polarity defects can be rescued by addition of exogenous fatty acids. By following the behavior of the pronucleus in emb-8 and pod-2 mutant embryos, we demonstrate that loss of polarity correlates with impaired interaction between the pronucleus-centrosome complex and the posterior cortex. CONCLUSIONS: The characterization of emb-8 and pod-2 mutant embryos suggests that the pronucleus-centrosome complex interaction with the cortex plays a direct role in establishing polarity and that fatty acid pathways are important for this polarizing event.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Cumulative indoor exposures to Semi-Volatile Organic Compounds (SVOCs) in France: the ECOS project.
International audienceSemivolatile organic compounds (SVOCs) are widely used indoor as plasticizers, flame retardants, or pesticides. They are present in indoor environments both in air (as gas and suspended particles) and settled dust. Thus exposition to possibly harmful agents: (phthalates, polybromodiphenylethers, organophosphorous compounds...) occurs (Mitchell et al. 2007;Wu et al. 2007). Here is presented the framework of the ECOS project, which objective is to assess domestic cumulative exposure to these substances and associated health risks
Proof of the Pudding: Applying the City-zen Methodology to Other European Cities.
Back in 2012, a group of enthusiasts submitted a project proposal to the EU. Many talks, partner proposals, and city
explorations later, City-zen was granted EU-funding âto develop and demonstrate energy efficient cities and to build a
methodology and tools for cities, industries and citizens to reach the 20-20-20 targetsâ. The program, rooted in Amsterdam (NL) and Grenoble (FR), had its first official kick-off in March 2014.
In the past five years, no less than 28 partners have been working on 20 pilot projects, aiming for an annual saving of an impressive 59,000 tonnes of CO2. Academics, industries and residents have been brought together to face the citiesâ challenges. An integrated methodology has been developed, as have roadmaps to sustainability for Grenoble and Amsterdam.
City-zen did not shield its learning from other urban environments, either. A vehicle aptly named the âRoadshowâ sent a group of experts in the fields of sustainability, energy, and urban design to various European cities to ideate with local governments, knowledge institutions, entrepreneurs and residents. Based on the results of workshops, field visits and serious games, municipalities have been shown feasible avenues towards sustainability. Next to Amsterdam and Grenoble, the following European cities were visited: Belfast, Izmir, Dubrovnik, Menorca, Sevilla, Roeselare, Preston, Nicosia (north and south), and Amersfoort.
This interactive book, entitled 'A TALE OF TWO CITIES' documents all City-zen activities since 2012, including those of the Roadshow in the section "Proof of the Pudding' (pp.40-43). The book has been fully translated in English and French, highlighting its international reach and collaborative network. Included in the Roadshow section are quotations of support from two key city decision makers, Mayor Declercq of Roeselare (Belgium) and Mayor Bolsius of Amersfoort (The Netherlands). Both City Mayors worked with the Roadshow when the project visited their cities in April 2018 and October 2019 respectively
Sub-Nucleocapsid Nanoparticles: A Nasal Vaccine against Respiratory Syncytial Virus
Background: Bronchiolitis caused by the respiratory syncytial virus (RSV) in infants less than two years old is a growing public health concern worldwide, and there is currently no safe and effective vaccine. A major component of RSV nucleocapsid, the nucleoprotein (N), has been so far poorly explored as a potential vaccine antigen, even though it is a target of protective anti-viral T cell responses and is remarkably conserved between human RSV A and B serotypes. We recently reported a method to produce recombinant N assembling in homogenous rings composed of 10â11 N subunits enclosing a bacterial RNA. These nanoparticles were named sub-nucleocapsid ring structure (N SRS). Methodology and Principal Findings: The vaccine potential of N SRS was evaluated in a well-characterized and widely acknowledged mouse model of RSV infection. BALB/c adult mice were immunized intranasally with N SRS adjuvanted with the detoxified E. coli enterotoxin LT(R192G). Upon RSV challenge, vaccinated mice were largely protected against virus replication in the lungs, with a mild inflammatory lymphocytic and neutrophilic reaction in their airways. Mucosal immunization with N SRS elicited strong local and systemic immunity characterized by high titers of IgG1, IgG2a and IgA anti-N antibodies, antigen-specific CD8+ T cells and IFN-c-producing CD4+ T cells. Conclusions/Significance: This is the first report of using nanoparticles formed by the recombinant nucleocapsid protein as an efficient and safe intra-nasal vaccine against RSV
Standardization of in vitro digestibility and DIAAS method based on the static INFOGEST protocol
Background: The FAO recommends the digestible indispensable amino acid score (DIAAS) as the measure for protein quality, for which the true ileal digestibility needs to be assessed in humans or pigs. However, due to high costs and ethical concerns, the FAO strongly encourages as well the development of validated in vitro methods, which complement the in vivo experiments.
Method: Recently, an in vitro workflow, based on the validated static INFOGEST protocol, was developed and compared towards in vivo data. In parallel to the validation with in vivo data, the repeatability and reproducibility of the in vitro protocol were tested in an international ring trial (RT) with the aim to establish an international ISO standard method within the International Dairy Federation (IDF). Five different dairy products (skim milk powder, whole
milk powder, whey protein isolate, yoghurt, and cheese) were analyzed in 32 different laboratories from 18 different countries, across 4 continents.
Results: in vitro protein digestibilities based on Nitrogen, free R-NH2, and total amino acids as well as DIAAS values were calculated and compared to in vivo data, where available.
Conclusion: The in vitro method is suited for quantification of digestibility and will be further implemented to other food matricesinfo:eu-repo/semantics/publishedVersio
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