Determination of the Boltzmann constant by laser spectroscopy as a basis for future measurements of the thermodynamic temperature

In this paper, we present the latest results on the measurement of the Boltzmann constant kB, by laser spectroscopy of ammonia at 10 ?m. The Doppler absorption profile of a ro-vibrational line of an NH3 gas sample at thermal and pressure equilibrium is measured as accurately as possible. The absorption cell is placed inside a large 1m3 thermostat filled with an ice-water mixture, which sets the temperature very close to 273.15 K. Analysing this profile, which is related to the Maxwell-Boltzmann molecular speed distribution, leads to a determination of the Boltzmann constant via a measurement of the Doppler width (proportional tosqrt(kBT)). A spectroscopic determination of the Boltzmann constant with an uncertainty as low as 37 ppm is obtained. Recent improvements with a new passive thermostat lead to a temperature accuracy, stability and homogeneity of the absorption cell better than 1 ppm over a day

Measurement of the Boltzmann constant by the Doppler broadening technique at a 3,8x10-5 accuracy level

In this paper, we describe an experiment performed at the Laboratoire de Physique des Lasers and dedicated to an optical measurement of the Boltzmann constant. With the proposed innovative technique, determining comes down to an ordinary frequency measurement. The method consists in measuring as accurately as possible the Doppler absorption profile of a rovibrational line of ammonia in thermal equilibrium. This profile is related to the Maxwell-Boltzmann molecular velocity distribution along the laser beam. A fit of the absorption line shape leads to a determination of the Doppler width proportional to sqrt(kT) and thus to a determination of the Boltzmann constant. The laser source is an ultra-stable CO2 laser with a wavelength . The absorption cell is placed in a thermostat keeping the temperature at 273.15 K within 1.4 mK. We were able to measure with a relative uncertainty as small as 3.8x10-5, which represents an improvement of an order of magnitude for an integration time comparable to our previous measurement published in 2007 [1

The media and intellectuals' response to medical publications: the antidepressants' case

During the last decade, there was a debate concerning the true efficacy of antidepressants. Several papers were published in scientific journals, but many articles were also published in the lay press and the internet both by medical scientists and academics from other disciplines or representatives of societies or initiatives. The current paper analyzes the articles authored by three representative opinion makers: one academic in medicine, one academic in philosophical studies, and a representative of an activists' group against the use of antidepressants. All three articles share similar gaps in knowledge and understanding of the scientific data and also are driven by an `existential-like' ideology. In our opinion, these articles have misinterpreted the scientific data, and they as such may misinform or mislead the general public and policy makers, which could have a potential impact upon public health. It seems that this line of thought represents another aspect of the stigma attached to people suffering from mental illness

The BIDS Toolbox: A web service to manage brain imaging datasets

Data sharing is a key factor for ensuring reproducibilityand transparency of scientific experiments, andneuroimaging is no exception. The vast heterogeneity of dataformats and imaging modalities utilised in the field makes it avery challenging problem. In this context, the Brain ImagingData Structure (BIDS) appears as a solution for organising anddescribing neuroimaging datasets. Since its publication in 2015,BIDS has gained widespread attention in the field, as it providesa common way to arrange and share multimodal brain images.Although the evident benefits it presents, BIDS has not beenwidely adopted in the field of MRI yet and we believe that thisis due to the lack of a go-to tool to create and managed BIDSdatasets. Motivated by this, we present the BIDS Toolbox, aweb service to manage brain imaging datasets in BIDS format.Different from other tools, the BIDS Toolbox allows the creationand modification of BIDS-compliant datasets based on MRI data.It provides both a web interface and REST endpoints for its use.In this paper we describe its design and early prototype, andprovide a link to the public source code repository

Taklobo Tours: Conservation, Tourism and Livelihood Opportunities in the Island Garden City of Samal, Southern Philippines

Taklobo Tours was launched in 2013 at Adecor, Samal Island, Southern Philippines, to promote giant clam conservation, ecotourism, and provide livelihood to 19 fisherfolk beneficiaries. This is to address the observations that coastal communities in Barangay Adecor and other areas in Region XI have violated RA 8550 on the rules and regulations of the CITES-listed species, Tridacna spp., and that fisherfolk have low income. This study aims to determine the impacts of Taklobo Tours to conservation, tourism, and livelihood of beneficiaries. Qualitative and quantitative data from 2013 to 2015 were used to analyze and describe the impacts. On top of the existing in-situ conservation of giant clams in a marine protected area (MPA), capacity building, conservation advocacy, policy support, and site development were among the site interventions. To date, the beneficiaries have increased their level of participation as conservation advocates, violations are no longer observed in the barangay, and communities have shown strong support for the advocacy. Being the banner tourism project of the local government, it has an increasing number of guests from 284 per month in 2013 to 700 per month in 2015, but usually higher during peak months of April and May. A total of 11,611 local and international guests visited and contributed to the income from fees amounting to PhP835,195.00. This provided additional income of PhP50 to PhP700 per month in 2013 and PhP500 to PhP4,800 per month in 2015 to the beneficiaries and sustainability fund to the project. This remarkable journey was made possible through the strong partnership of academe with local government units of Island Garden City of Samal and Adecor for technical assistance, promotion, management, and legislations. Regular monitoring is recommended to ensure project sustainability

Geomorphological significance of Ontario Lacus on Titan: Integrated interpretation of Cassini VIMS, ISS and RADAR data and comparison with the Etosha Pan (Namibia)

International audienceOntario Lacus is the largest lake of the whole southern hemisphere of Titan, Saturn's major moon. It has been imaged twice by each of the Cassini imaging systems (Imaging Science Subsystem (ISS) in 2004 and 2005, Visual and Infrared Mapping Spectrometer (VIMS) in 2007 and 2009 and Radar in 2009 and 2010). In this study, we take advantage of each imaging dataset to establish a global survey of Ontario Lacus' environment from 2005 to 2010. We perform a geomorphological mapping and interpretation of Ontario Lacus, mainly based on a joint analysis of VIMS and Radar SAR datasets, along with the T49 altimetric profile acquired in December 2008. The morphologies observed on Ontario Lacus are compared to landforms of a semi-arid terrestrial analog, which closely resembles Titan's lakes: the pans of the Etosha Basin, located in Namibia. From this comparison, we infer that Ontario Lacus is an extremely flat depression where liquids, only located in the darkest areas in the Radar data, cover topographic lows where the "alkanofer" would raise above the depression floor. The rest of the depression appears rather as a muddy flat surface likely composed of a thick coating of photon-absorbing materials, explaining its still rather dark appearance in the infrared and radar data. We also determined whether surface changes occurred during the 5 years time interval between 2005 and 2010. We found that the depression contour is constant at the resolution of ISS and VIMS data, both being consistent with the depression contour derived from the Radar data. Our interpretation, in which the liquids are located only in some parts of Ontario Lacus, agrees with the lack of significant change of the depression contour between 2007 (and 2005 with more uncertainties) and 2010

Implementation of ultrasonic sensing for high resolution measurement of binary gas mixture fractions

We describe an ultrasonic instrument for continuous real-time analysis of the fractional mixture of a binary gas system. The instrument is particularly well suited to measurement of leaks of a high molecular weight gas into a system that is nominally composed of a single gas. Sensitivity < 5 × 10−5 is demonstrated to leaks of octaflouropropane (C3F8) coolant into nitrogen during a long duration (18 month) continuous study. The sensitivity of the described measurement system is shown to depend on the difference in molecular masses of the two gases in the mixture. The impact of temperature and pressure variances on the accuracy of the measurement is analysed. Practical considerations for the implementation and deployment of long term, in situ ultrasonic leak detection systems are also described. Although development of the described systems was motivated by the requirements of an evaporative fluorocarbon cooling system, the instrument is applicable to the detection of leaks of many other gases and to processes requiring continuous knowledge of particular binary gas mixture fractions

Naturalness and Fine Tuning in the NMSSM: Implications of Early LHC Results

We study the fine tuning in the parameter space of the semi-constrained NMSSM, where most soft Susy breaking parameters are universal at the GUT scale. We discuss the dependence of the fine tuning on the soft Susy breaking parameters M_1/2 and m0, and on the Higgs masses in NMSSM specific scenarios involving large singlet-doublet Higgs mixing or dominant Higgs-to-Higgs decays. Whereas these latter scenarios allow a priori for considerably less fine tuning than the constrained MSSM, the early LHC results rule out a large part of the parameter space of the semi-constrained NMSSM corresponding to low values of the fine tuning.Comment: 19 pages, 10 figures, bounds from Susy searches with ~1/fb include

Transgenic expression of the dicotyledonous pattern recognition receptor EFR in rice leads to ligand-dependent activation of defense responses

Plant plasma membrane localized pattern recognition receptors (PRRs) detect extracellular pathogen-associated molecules. PRRs such as Arabidopsis EFR and rice XA21 are taxonomically restricted and are absent from most plant genomes. Here we show that rice plants expressing EFR or the chimeric receptor EFR::XA21, containing the EFR ectodomain and the XA21 intracellular domain, sense both Escherichia coli- and Xanthomonas oryzae pv. oryzae (Xoo)-derived elf18 peptides at sub-nanomolar concentrations. Treatment of EFR and EFR::XA21 rice leaf tissue with elf18 leads to MAP kinase activation, reactive oxygen production and defense gene expression. Although expression of EFR does not lead to robust enhanced resistance to fully virulent Xoo isolates, it does lead to quantitatively enhanced resistance to weakly virulent Xoo isolates. EFR interacts with OsSERK2 and the XA21 binding protein 24 (XB24), two key components of the rice XA21-mediated immune response. Rice-EFR plants silenced for OsSERK2, or overexpressing rice XB24 are compromised in elf18-induced reactive oxygen production and defense gene expression indicating that these proteins are also important for EFR-mediated signaling in transgenic rice. Taken together, our results demonstrate the potential feasibility of enhancing disease resistance in rice and possibly other monocotyledonous crop species by expression of dicotyledonous PRRs. Our results also suggest that Arabidopsis EFR utilizes at least a subset of the known endogenous rice XA21 signaling components

Reply to: New Meta- and Mega-analyses of Magnetic Resonance Imaging Findings in Schizophrenia: Do They Really Increase Our Knowledge About the Nature of the Disease Process?

This work was supported by National Institute of Biomedical Imaging and Bioengineering Grant No. U54EB020403 (to the ENIGMA consortium)