First observation of electric-quadrupole infrared transitions in water vapour

Molecular absorption of infrared radiation is generally due to ro-vibrational electric-dipole transitions. Electric-quadrupole transitions may still occur, but they are typically a million times weaker than electric-dipole transitions, rendering their observation extremely challenging. In polyatomic or polar diatomic molecules, ro-vibrational quadrupole transitions have never been observed. Here, we report the first direct detection of quadrupole transitions in water vapor. The detected quadrupole lines have intensity largely above the standard dipole intensity cut-off of spectroscopic databases and thus are important for accurate atmospheric and astronomical remote sensing

Validation Tests of the W2020 Energy Levels of Water Vapor

A decade ago, a task group of the International Union of Pure and Applied Chemistry performed an exhaustive collection and review of measured transitions, applied the MARVEL procedure, and derived recommended empirical energy levels for nine major water isotopologues. Very recently, using an improved methodology, the sets of empirical energy levels of H216O, H218O and H217O were updated, leading to the so-called W2020 energy levels and transition wavenumbers [Furtenbacher et al. J. Phys. Chem. Ref. Data 49 (2020) 043103; 10.1063/5.0030680]. Here we present validation tests of the W2020 line list of H216O against spectra recorded by cavity ring down spectroscopy (CRDS) referenced to a frequency comb (FC), newly obtained in the 8040-8630 cm−1 region. The recorded spectra are found in excellent agreement with previous high-quality studies available in the literature. While these literature sources were all incorporated in the transition database used to derive the W2020 energy levels, the direct superposition of the FC-CRDS spectra to the W2020 line list of H216O shows a number of large disagreements. Cases where deviations largely exceed the W2020 claimed uncertainty on the transition frequencies are noted. In the considered spectral region, the resulting W2020 list is thus less accurate than some of the published original sources used to derive the W2020 energy levels. We conclude that the sophisticated global procedure and algorithm elaborated to identify and adequately weight inaccurate line positions among the large W2020 transition database do not always prevent less accurate data from “spoiling” higher quality data sources. The W2020 list of H216O is also compared to newly recorded CRDS spectra in the 12970–13200 cm−1 region (corresponding to the region of the A-band of O2), where previous observations were very scarce. As in the previous region, substantial position deviations are evidenced, and in many cases, the W2020 error bars appear to be strongly underestimated. © 2021 Elsevier LtdThe support of the CNRS (France) in the frame of International Research Project SAMIA is acknowledged. SNM activity was also partly supported in the frame of the Russian Science Foundation, Grant No. 18-11-00024-Π. CRDS measurements near 760 nm were performed at IAO-Tomsk and funded by RFBR project 20-32-70054

New transitions and energy levels of water vapor by high sensitivity CRDS near 1.73 and 1.54 µm

This contribution is part of a long term project aiming at improving the water absorption spectroscopy by high sensitivity cavity ring down spectroscopy (CRDS) in the near infrared. Two new sources of CRDS spectra are considered: (i) The room temperature absorption spectrum of water vapor in natural isotopic abundance is recorded near 1.73 µm. A series of recordings was performed from 5693 to 5991 cm−1 with a pressure value of about 6 Torr. The noise equivalent absorption (αmin) of the spectra is better than 10− 10 cm−1. A total of 1453 lines were assigned to 1573 transitions of four water isotopologues (H2 16O, H2 17O, H2 18O and HD16O). Their intensities span more than five orders of magnitude from 3.0 × 10−30 to 4.7 × 10−25 cm/molecule at 296 K. The assignments were performed using known experimental energy levels as well as calculated line lists based on the results of Schwenke and Partridge. Two hundred fifty-one lines (assigned to 280 transitions) are observed for the first time and twelve energy levels are newly determined. The comparison of the obtained line parameters with those of the HITRAN database is discussed. Forty-six line positions are observed to significantly differ from their HITRAN values (δν = │νHITRAN – νCRDS│ > 0.02 cm−1). The derived set of energy levels is compared to those recommended by an IUPAC task group. (ii) The room temperature CRDS spectrum of water vapor highly enriched in 17O was recorded near 1.54 µm (6223–6672 cm−1) at a pressure of 12 Torr. Compared to a previous study, the higher pressure of the recordings allowed for extending the observations. Overall, twenty-six new levels were determined for both H2 17O and HD17O. All these observations together with other recent measurements will allow for an extension and an update of our empirical database in the 5693– 8340 cm−1 region. © 2019 Elsevier Lt

Etude De L’évolution Du Trait De Côte À L’aide De L’outil Mobitc : Cas Du Littoral De Grand-Bassam

This study proposes an assessment of the historical coastline (TDC) mobility of the Ivorian coastline, specifically the Grand-Bassam coastline (Côte d'Ivoire), and suggests reflections on the sustainable management of the coastal environment in Côte d'Ivoire, taking into account coastal erosion. The objective is to evaluate, using the MobiTC software, the spatio-temporal and statistical evolution of the morphology of the Grand-Bassam coastal zone in order to plan appropriate coastal developments. Specifically, it is to extract images on google earth, to treat them under MobiTC and to analyze the rate of spatio-temporary and statistical evolution of coastlines. To do this, data from QuickBird images provided by Google Earth from 1984, 1988, 1992, 1996, 2000, 2004, 2008, 2012 and 2016 in the study area were used. Different software was used for image processing. The ENVI 5.1 software allowed georeferencing and thresholding to make the images superimposable and highlight the baseline. The digitization of the images was done with ArcGis software. The QGIS 2.18 software was used to convert the .shp files to the mid / mif format of the MobiTC software. The latter makes it possible to understand the statistical evolution of the coastline dynamics from the creation of a baseline, the skeleton of envelopes and traces. The variations observed between 1984 and 2016 show a fattening of 0.23 m / year in some sectors and an erosion rate of 0.34 m / year in other sectors. It is noted that 62.79% of the coastline is accretion and 37.21% is eroding

An intergenerational study of perceptions of changes in active free play among families from rural areas of Western Canada

Background: Children's engagement in active free play has declined across recent generations. Therefore, the purpose of this study was to examine perceptions of intergenerational changes in active free play among families from rural areas. We addressed two research questions: (1) How has active free play changed across three generations? (2) What suggestions do participants have for reviving active free play? Methods: Data were collected via 49 individual interviews with members of 16 families (15 grandparents, 16 parents, and 18 children) residing in rural areas/small towns in the Province of Alberta (Canada). Interview recordings were transcribed verbatim and subjected to thematic analysis guided by an ecological framework of active free play. Results: Factors that depicted the changing nature of active free play were coded in the themes of less imagination/more technology, safety concerns, surveillance, other children to play with, purposeful physical activity, play spaces/organized activities, and the good parenting ideal. Suggestions for reviving active free play were coded in the themes of enhance facilities to keep kids entertained, provide more opportunities for supervised play, create more community events, and decrease use of technology. Conclusions: These results reinforce the need to consider multiple levels of social ecology in the study of active free play, and highlight the importance of community-based initiatives to revive active free play in ways that are consistent with contemporary notions of good parentin

The HITRAN2020 Molecular Spectroscopic Database

The HITRAN database is a compilation of molecular spectroscopic parameters. It was established in the early 1970s and is used by various computer codes to predict and simulate the transmission and emission of light in gaseous media (with an emphasis on terrestrial and planetary atmospheres). The HITRAN compilation is composed of five major components: the line-by-line spectroscopic parameters required for high-resolution radiative-transfer codes, experimental infrared absorption cross-sections (for molecules where it is not yet feasible for representation in a line-by-line form), collision-induced absorption data, aerosol indices of refraction, and general tables (including partition sums) that apply globally to the data. This paper describes the contents of the 2020 quadrennial edition of HITRAN. The HITRAN2020 edition takes advantage of recent experimental and theoretical data that were meticulously validated, in particular, against laboratory and atmospheric spectra. The new edition replaces the previous HITRAN edition of 2016 (including its updates during the intervening years). All five components of HITRAN have undergone major updates. In particular, the extent of the updates in the HITRAN2020 edition range from updating a few lines of specific molecules to complete replacements of the lists, and also the introduction of additional isotopologues and new (to HITRAN) molecules: SO, CH3F, GeH4, CS2, CH3I and NF3. Many new vibrational bands were added, extending the spectral coverage and completeness of the line lists. Also, the accuracy of the parameters for major atmospheric absorbers has been increased substantially, often featuring sub-percent uncertainties. Broadening parameters associated with the ambient pressure of water vapor were introduced to HITRAN for the first time and are now available for several molecules. The HITRAN2020 edition continues to take advantage of the relational structure and efficient interface available at www.hitran.org and the HITRAN Application Programming Interface (HAPI). The functionality of both tools has been extended for the new edition

Co-limitation towards lower latitudes shapes global forest diversity gradients

The latitudinal diversity gradient (LDG) is one of the most recognized global patterns of species richness exhibited across a wide range of taxa. Numerous hypotheses have been proposed in the past two centuries to explain LDG, but rigorous tests of the drivers of LDGs have been limited by a lack of high-quality global species richness data. Here we produce a high-resolution (0.025° × 0.025°) map of local tree species richness using a global forest inventory database with individual tree information and local biophysical characteristics from ~1.3 million sample plots. We then quantify drivers of local tree species richness patterns across latitudes. Generally, annual mean temperature was a dominant predictor of tree species richness, which is most consistent with the metabolic theory of biodiversity (MTB). However, MTB underestimated LDG in the tropics, where high species richness was also moderated by topographic, soil and anthropogenic factors operating at local scales. Given that local landscape variables operate synergistically with bioclimatic factors in shaping the global LDG pattern, we suggest that MTB be extended to account for co-limitation by subordinate drivers

Metabolic syndrome: definitions and controversies

Metabolic syndrome (MetS) is a complex disorder defined by a cluster of interconnected factors that increase the risk of cardiovascular atherosclerotic diseases and diabetes mellitus type 2. Currently, several different definitions of MetS exist, causing substantial confusion as to whether they identify the same individuals or represent a surrogate of risk factors. Recently, a number of other factors besides those traditionally used to define MetS that are also linked to the syndrome have been identified. In this review, we critically consider existing definitions and evolving information, and conclude that there is still a need to develop uniform criteria to define MetS, so as to enable comparisons between different studies and to better identify patients at risk. As the application of the MetS model has not been fully validated in children and adolescents as yet, and because of its alarmingly increasing prevalence in this population, we suggest that diagnosis, prevention and treatment in this age group should better focus on established risk factors rather than the diagnosis of MetS

Control of sand flies with attractive toxic sugar baits (ATSB) and potential impact on non-target organisms in Morocco

International audienceBackground: The persistence and geographical expansion of leishmaniasis is a major public health problem that requires the development of effective integrated vector management strategies for sand fly control. Moreover, these strategies must be economically and environmentally sustainable approaches that can be modified based on the current knowledge of sand fly vector behavior. The efficacy of using attractive toxic sugar baits (ATSB) for sand fly control and the potential impacts of ATSB on non-target organisms in Morocco was investigated. Methods: Sand fly field experiments were conducted in an agricultural area along the flood plain of the Ourika River. Six study sites (600 m x 600 m); three with ``sugar rich'' (with cactus hedges bearing countless ripe fruits) environments and three with ``sugar poor'' (green vegetation only suitable for plant tissue feeding) environments were selected to evaluate ATSB, containing the toxin, dinotefuran. ATSB applications were made either with bait stations or sprayed on non-flowering vegetation. Control sites were established in both sugar rich and sugar poor environments. Field studies evaluating feeding on vegetation treated with attractive (non-toxic) sugar baits (ASB) by non-target arthropods were conducted at both sites with red stained ASB applied to non-flowering vegetation, flowering vegetation, or on bait stations. Results: At both the sites, a single application of ATSB either applied to vegetation or bait stations significantly reduced densities of both female and male sand flies (Phlebotomus papatasi and P. sergenti) for the five-week trial period. Sand fly populations were reduced by 82.8% and 76.9% at sugar poor sites having ATSB applied to vegetation or presented as a bait station, respectively and by 78.7% and 83.2%, respectively at sugar rich sites. The potential impact of ATSB on non-targets, if applied on green non-flowering vegetation and bait stations, was low for all non-target groups as only 1% and 0.7% were stained with non-toxic bait respectively when monitored after 24 hours. Conclusions: The results of this field study demonstrate ATSB effectively controls both female and male sand flies regardless of competing sugar sources. Furthermore, ATSB applied to foliar vegetation and on bait stations has low non-target impact