True density of soot particles: A comparison of results highlighting the influence of the organic contents

International audienc

Gamete biology: Perspectives for Bluefin Tuna Aquaculture

Taking care of fish reproductive physiology and gamete biology allowed significant progresses in fry production control for many commercially interesting fish. Can it be a similar situation for bluefin tuna? Fish gamete production results from long processes controlled mainly by climatic conditions, mediated by neuroendocrine and endocrine factors. The possibility to monitor the development of germinal cells by successive sampling in individual fish which easily breed in captivity, has allowed learning about the sequences of gametogenesis and their control, as well as important characteristics of fish gamete biology. The female ovarian cycle involves a progressive accumulation of yolk in the oocytes (i.e., vitellogenesis), followed by cytoplasmic and nuclear events related to maturation and ovulation. The phases of vitellogenesis and maturation are of different duration in different species. In captive fish the endocrine regulation of reproduction may be disrupted by stress, thus preventing spontaneous spawning, while the application of exogenous hormones at the conclusion of gametogenesis allowed production of good quality gametes. In males, gamete production is not continuous as in mammals. Spermatozoa are produced after a cycle that includes a resting period, followed by continuous or discontinuous sequences of spermatogenesis (spermatogenesis sensu stricto, spermiogenesis and spermiation). The discontinuity of fish sperm production may induce a phenomenon of ageing along the period of spermiation, which decreases the quality of semen with time. Wild bluefin tuna breed in specific areas during a short summer spawning season. When kept in cages in the area of Cartagena (Spain), they present developed gamete stages at the same time as wild fish, but, until now, neither mating behavior nor eggs have been observed as was the case in Japan. It has not been possible to monitor individual gonad recrudescence by successive sampling, due to inability to handle the fish without causing mortality, so that the reproduction failure remains unexplained. Hormonal stimulation may be an interesting alternative but its use requires an assessment of gonadal stage to be performed properly. The high post-handling mortality of bluefin tuna in captivity is a real bottleneck for reproduction control. The improvement of handling and the use of less stress-susceptible individuals may be a major progress for bluefin tuna reproduction control. The occurrence of a second generation of juveniles in Japan, subjected to first domestication selection may provide very interesting experimental fish.EU 5FP REPRODOTT (Q5RS-2002-01355

Compact in-vacuum gamma-ray spectrometer for high-repetition rate PW-class laser-matter interaction

With the advent of high repetition rate laser facilities, novel diagnostic tools compatible with these advanced specifications are in demand. This paper presents the design of an active gamma-ray spectrometer intended for these high repetition rate experiments, with particular emphasis on functionality within a PW level laser-plasma interaction chamber's extreme conditions. The spectrometer uses stacked scintillators to accommodate a broad range of gamma-ray energies, demonstrating its adaptability for various experimental setups. Additionally, it has been engineered to maintain compactness, electromagnetic pulse resistance, and ISO-5 cleanliness requirements while ensuring high sensitivity. The paper also outlines the unfolding process, to recover the gamma-ray spectrum from the spectrometer's captured image thanks to a calibration using a $^{60}$Co source

Pan-European rural monitoring network shows dominance of NH3 gas and NH4NO3 aerosol in inorganic atmospheric pollution load

A comprehensive European dataset on monthly atmospheric NH3, acid gases (HNO3, SO2, HCl), and aerosols (NH4+, NO3-, SO42-, Cl−, Na+, Ca2+, Mg2+) is presented and analysed. Speciated measurements were made with a low-volume denuder and filter pack method (DEnuder for Long-Term Atmospheric sampling, DELTA®) as part of the EU NitroEurope (NEU) integrated project. Altogether, there were 64 sites in 20 countries (2006–2010), coordinated between seven European laboratories. Bulk wet-deposition measurements were carried out at 16 co-located sites (2008–2010). Inter-comparisons of chemical analysis and DELTA® measurements allowed an assessment of comparability between laboratories. The form and concentrations of the different gas and aerosol components measured varied between individual sites and grouped sites according to country, European regions, and four main ecosystem types (crops, grassland, forests, and semi-natural). The smallest concentrations (with the exception of SO42- and Na+) were in northern Europe (Scandinavia), with broad elevations of all components across other regions. SO2 concentrations were highest in central and eastern Europe, with larger SO2 emissions, but particulate SO42- concentrations were more homogeneous between regions. Gas-phase NH3 was the most abundant single measured component at the majority of sites, with the largest variability in concentrations across the network. The largest concentrations of NH3, NH4+ and NO-3 were at cropland sites in intensively managed agricultural areas (e.g. Borgo Cioffi in Italy), and the smallest were at remote semi-natural and forest sites (e.g. Lompolojänkkä, Finland), highlighting the potential for NH3 to drive the formation of both NH4+ and NO3- aerosol. In the aerosol phase, NH4+ was highly correlated with both NO3- and SO42-, with a near-1:1 relationship between the equivalent concentrations of NH4+ and sum(NO3- + SO42-) of which around 60 % was as NH4NO3. Distinct seasonality was also observed in the data, influenced by changes in emissions, chemical interactions, and the influence of meteorology on partitioning between the main inorganic gases and aerosol species. Springtime maxima in NH3 were attributed to the main period of manure spreading, while the peak in summer and trough in winter were linked to the influence of temperature and rainfall on emissions, deposition, and gas–aerosol-phase equilibrium. Seasonality in SO2 was mainly driven by emissions (combustion), with concentrations peaking in winter, except in southern Europe, where the peak occurred in summer. Particulate SO42− showed large peaks in concentrations in summer in southern and eastern Europe, contrasting with much smaller peaks occurring in early spring in other regions. The peaks in particulate SO42- coincided with peaks in NH3 concentrations, attributed to the formation of the stable (NH4)2SO4. HNO3 concentrations were more complex, related to traffic and industrial emissions, photochemistry, and HNO3:NH4NO3 partitioning. While HNO3 concentrations were seen to peak in the summer in eastern and southern Europe (increased photochemistry), the absence of a spring peak in HNO3 in all regions may be explained by the depletion of HNO3 through reaction with surplus NH3 to form the semi-volatile aerosol NH4NO3. Cooler, wetter conditions in early spring favour the formation and persistence of NH4NO3 in the aerosol phase, consistent with the higher springtime concentrations of NH4+ and NO3−. The seasonal profile of NO3- was mirrored by NH4+, illustrating the influence of gas–aerosol partitioning of NH4NO3 in the seasonality of these components. Gas-phase NH3 and aerosol NH4NO3 were the dominant species in the total inorganic gas and aerosol species measured in the NEU network. With the current and projected trends in SO2, NOx , and NH3 emissions, concentrations of NH3 and NH4NO3 can be expected to continue to dominate the inorganic pollution load over the next decades, especially NH3, which is linked to substantial exceedances of ecological thresholds across Europe. The shift from (NH4)2SO4 to an atmosphere more abundant in NH4NO3 is expected to maintain a larger fraction of reactive N in the gas phase by partitioning to NH3 and HNO3 in warm weather, while NH4NO3 continues to contribute to exceedances of air quality limits for PM2.5

Can we identify response markers to antihypertensive drugs? First results from the Ideal Trial

Current antihypertensive strategies do not take into account that individual characteristics may influence the magnitude of blood pressure (BP) reduction. Guidelines promote trial-and-error approaches with many different drugs. We conducted the Identification of the Determinants of the Efficacy of Arterial blood pressure Lowering drugs (IDEAL) Trial to identify factors associated with BP responses to perindopril and indapamide. IDEAL was a cross-over, double-blind, placebo-controlled trial, involving four 4-week periods: indapamide, perindopril and two placebo. Eligible patients were untreated, hypertensive and aged 25-70 years. The main outcome was systolic BP (SBP) response to drugs. The 112 participants with good compliance had a mean age of 52. One in every three participants was a woman. In middle-aged women, the SBP reduction from drugs was -11.5 mm Hg (indapamide) and -8.3 mm Hg (perindopril). In men, the response was significantly smaller: -4.8 mm Hg (indapamide) and -4.3 (perindopril) (P for sex differences 0.001 and 0.015, respectively). SBP response to perindopril decreased by 2 mm Hg every 10 years of age in both sexes (P=0.01). The response to indapamide increased by 3 mm Hg every 10 years of age gradient in women (P=0.02). Age and sex were important determinants of BP response for antihypertensive drugs in the IDEAL population. This should be taken into account when choosing drugs a priori.Journal of Human Hypertension advance online publication, 17 April 2014; doi:10.1038/jhh.2014.29

Posibilidades de reproducción del atún rojo, Thunnus thynnus, en cautividad

This paper describes results achieved in a 3-year-long research project supported by the European Commission (EU) aimed at studying the feasibility to achieve reproduction of Bluefin tuna (BFT), Thunnus thynnus, in captivity. The project involves nine partners from seven Mediterranean countries. The overall objective of this project is to improve our understanding of the reproductive physiology of BFT as the basis to develop a suitable methodology for the control of its reproduction in captivity. Results have indicated that BFT reared in captivity are able to achieve maturation and spawn, naturally or hormonally induced, and consequently get larvae by in vitro fertilization. Thus, opening the possibility to an eco-friendly and economically sustainable production of BFT in the Mediterranean