The Epigenetic Repertoire of Daphnia magna Includes Modified Histones

Daphnids are fresh water microcrustaceans, many of which follow a cyclically parthenogenetic life cycle. Daphnia species have been well studied in the context of ecology, toxicology, and evolution, but their epigenetics remain largely unexamined even though sex determination, the production of sexual females and males, and distinct adult morphological phenotypes, are determined epigenetically. Here, we report on the characterization of histone modifications in Daphnia. We show that a number of histone H3 and H4 modifications are present in Daphnia embryos and histone H3 dimethylated at lysine 4 (H3K4me2) is present nonuniformly in the nucleus in a cell cycle-dependent manner. In addition, this histone modification, while present in blastula and gastrula cells as well as the somatic cells of adults, is absent or reduced in oocytes and nurse cells. Thus, the epigenetic repertoire of Daphnia includes modified histones and as these epigenetic forces act on a genetically homogeneous clonal population Daphnia offers an exceptional tool to investigate the mechanism and role of epigenetics in the life cycle and development of an ecologically important species

Multi-tool formaldehyde measurement in simulated and real atmospheres for indoor air survey and concentration change monitoring

International audienceFormaldehyde is of particular health concern since it is carcinogenic for human and ubiquitous in indoor air where people spend most of their time. Therefore, it is important to have suitable methods and techniques to measure its content in indoor air. In the present work, four different techniques have been tested in the INERIS exposure chamber and in indoor environments in comparison to a standard active method: passive sampling method based on the reaction of 2,4-dinitrophenylhydrazine with formaldehyde, two on-line continuous monitoring systems based on fluorescence and UV measurements and a portable commercialised analyser based on electrochemical titration. Two formaldehyde concentrations, about 10 and 25 μg m−3 were generated in an exposure chamber under controlled conditions of temperature, relative humidity, and wind speed to simulate real conditions and assess potential influence on passive sampling and continuous systems response. Influence of sampling periods on passive sampling has also been evaluated. The real atmosphere experiments have been performed in four different indoor environments: an office, a furniture shop, a shopping mall, and residential dwellings in which several potential formaldehyde sources linked to household activities have been tested. The analytical and sampling problems associated with each measurement method have been identified and discussed. An overall agreement between each technique has been observed and continuous analyzers allowed for formaldehyde concentrations change monitoring and secondary formation of that pollutant observation

Relativistic graphene ratchet on semidisk Galton board

Using extensive Monte Carlo simulations we study numerically and analytically a photogalvanic effect, or ratchet, of directed electron transport induced by a microwave radiation on a semidisk Galton board of antidots in graphene. A comparison between usual two-dimensional electron gas (2DEG) and electrons in graphene shows that ratchet currents are comparable at very low temperatures. However, a large mean free path in graphene should allow to have a strong ratchet transport at room temperatures. Also in graphene the ratchet transport emerges even for unpolarized radiation. These properties open promising possibilities for room temperature graphene based sensitive photogalvanic detectors of microwave and terahertz radiation.Comment: 4 pages, 4 figures. Research done at Quantware http://www.quantware.ups-tlse.fr/. More detailed analysis is give

Quantum Metrology Triangle Experiments: A Status Review

Quantum Metrology Triangle experiments combine three quantum electrical effects (the Josephson effect, the quantum Hall effect and the single-electron transport effect) used in metrology. These experiments allow important fundamental consistency tests on the validity of commonly assumed relations between fundamental constants of nature and the quantum electrical effects. This paper reviews the history, results and the present status and perspectives of Quantum Metrology Triangle experiments. It also reflects on the possible implications of results for the knowledge on fundamental constants and the quantum electrical effects.Comment: 36 pages, 8 figure

Thermal and hygroscopic study of hemp concrete in real ambient conditions

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Comparison of the effects of different surfactants on electrical parameters in Carbon Nanotube thin films

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A Randomised Controlled Trial of the I-Deal Life Skills Intervention with Syrian Refugee Adolescents in Northern Lebanon

Armed conflict and displacement pose threats to children’s mental health and psychosocial wellbeing. We report on the findings of an evaluation of I-Deal, a life skills intervention aimed at fostering resilience among early adolescent refugees. We used a parallel group randomised controlled trial to compare I-Deal to a structured recreational activity group (SRA). 325 adolescents in Akkar, Lebanon, 74% of them Syrian, were randomised to I-Deal or SRA. The primary outcome was psychosocial wellbeing; secondary outcomes included psychological distress, prosocial behaviour, hope, self-esteem and social connectedness. Assessments were conducted at baseline, endline and 3-month follow-up. Due to low reliabilities, only wellbeing, distress and hope were included in the analyses. These outcomes showed similar results: no statistically significant changes over time, no significant differences between groups and no significant interaction between group and time. Our findings do not support the effectiveness of I-Deal. Several factors are considered that may help explain the lack of effect, including the aspects of the intervention design, possible measurement error suggested by low reliabilities on several instruments and a ceiling effect on our primary outcome. A replication using rigorously piloted instruments, the selection of outcomes more specifically tailored to the intervention and a nonactive control condition could help provide definitive evidence regarding the effectiveness of the I-Deal intervention. Key implications for practice: - This study contributes to the growing literature on the effectiveness of life skills interventions for refugee adolescents. - The lack of any intervention effects in this study raises important questions about the appropriate focus and role of preventive and promotive interventions with refugee adolescents. - Methodological issues in the study underscore the vital importance of using validated and well piloted measures of appropriately selected intervention outcomes

A new device for formaldehyde and total aldehydes real-time monitoring

AIR+MSA:CGOA new sensitive technique for the quantification of formaldehyde (HCHO) and total aldehydes has been developed in order to monitor these compounds, which are known to be involved in air quality issues and to have health impacts. Our approach is based on a colorimetric method where aldehydes are initially stripped from the air into a scrubbing solution by means of a turning coil sampler tube and then derivatised with 3-methylbenzothiazolinone-2-hydrazone in acid media (pH = -0.5). Hence, colourless aldehydes are transformed into blue dyes that are detected by UV-visible spectroscopy at 630 nm. Liquid core waveguide LCW TeflonA (R) AF-2400 tube was used as innovative optical cells providing a HCHO detection limit of 4 pptv for 100 cm optical path with a time resolution of 15 min. This instrument showed good correlation with commonly used techniques for aldehydes analysis such as DNPH derivatisation chromatographic techniques with off-line and on-line samplers, and DOAS techniques (with deviation below 6 %) for both indoor and outdoor conditions. This instrument is associated with simplicity and low cost, which is a prerequisite for indoor monitoring

MBE-grown oxides-based resistive switching memristive devices

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