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The mid-infrared lightweight tunable diode laser hygrometer, "Pico-Light H 2 O", the successor to Pico-SDLA H 2 O, is presented and its performances are evaluated during the AsA 2022 balloon-borne intercomparison campaign conducted at the CNES Aire-sur-l'Adour (AsA, 43.70° N; 0.25° W) balloon launch facility and the Aeroclub d'Aire-sur-l'Adour in France. The Pico-Light instrument has primarily been developed for sounding of the upper troposphere and stratosphere, although during the AsA 2022 campaign we expand the range of comparison to include additionally the lower troposphere. Three different types of hygrometer and two models of radiosonde were flown, operated by the French Space Agency (CNES) and the NOAA Global Monitoring Laboratory (GML) scientific teams: Pico-Light H 2 O, the NOAA Frost Point Hygrometer (FPH), the micro-hygrometer (in an early phase of development), and M20 and iMet-4 sondes. Within this framework, we intend to validate measurements of Pico-Light H 2 O through a first intercomparison with the NOAA FPH instrument. The in situ monitoring of water vapour in the upper troposphere–lower stratosphere continues to be very challenging from an instrumental point of view because of the very small amounts of water vapour to be measured in these regions of the atmosphere. Between the lapse rate tropopause (11–12.3 km) and 20 km, the mean relative difference between water vapour mixing ratio measurements by Pico-Light H 2 O and NOAA FPH was 4.2 % ± 7.7 %, and the mean tropospheric difference was 3.84 % ± 23.64 %, with differences depending on the altitude range considered. In the troposphere, relative humidity (RH) over water comparisons led to agreement between Pico-Light and NOAA FPH of - 0.2 % on average, with excursions of about 30 % RH due to moisture variability. Expanding the comparison to meteorological sondes, the iMet-4 sondes agree well with both Pico-Light and FPH between the ground and 7.5 km (within ± 3 % RH), as do the M20 sondes, up to 13 km, which are wet-biased by 3 % RH and dry-biased by 20 % in cases of saturation. [ABSTRACT FROM AUTHOR]

The mid-infrared lightweight stratospheric hygrometer, "Pico-Light H2O", the successor of Pico-SDLA H2O, is presented and its performances are evaluated during the AsA 2022 balloon-borne intercomparison campaign conducted at CNES Aire-sur-l'Adour (AsA) balloon launch facility and the Aeroclub d'Aire-sur-l'Adour. The Pico-Light instrument primarily been developed for sounding of the upper troposphere and stratosphere. Though, during the AsA 2022 campaign we expand the range of comparison including the lower troposphere additionally. Three different types of hygrometers and two models of radiosonde were flown, operated by the French Space Agency (CNES) and the NOAA Global Monitoring Laboratory (GML) scientific teams: Pico-Light H2O, the NOAA Frost Point Hygrometer (FPH), the micro hygrometer (in an early phase of development), M20 and iMet-4 sondes. In this frame, we intend to validate measurements of Pico-Light H2O through a first intercomparison with the NOAA FPH instrument. The in situ monitoring of water vapour in the UT-LS keeps being very challenging from an instrumental point of view because of the very small amounts of water vapour to be measured in these regions of the atmosphere. Between the lapse rate tropopause (11 to 12.3 km) and 20 km, the mean relative difference between water vapour mixing ratio measurements by Pico-Light H2O and NOAA FPH was (4.2 ± 7.7) %, mean tropospheric difference is was (3.84 ± 23.64)%, with differences depending on the altitude range considered. In the troposphere, relative humidity over water (RH) comparisons leads to an agreement between both Pico-Light and NOAA FPH of -0.2% on average, with excursions of about 30% RH due to moisture variability. Expanding the comparison to meteorological sondes, the iMet-4 sondes agree well with both Pico-Light and FPH between ground and 7.5 km (within ± 3% RH) and so does for M20 sondes, up to 13 km, which are wet biased by 3% RH and dry biased by 20% in case of saturation. [ABSTRACT FROM AUTHOR]

• Fast pyrolysis of mannan-rich ivory nut was performed at 350 °C and 500 °C. • Pyrolysis liquids (yield 58–60 wt%) were rich in levomannosan and 5-hydroxymethyl furfural. • Biochar and non-condensible gases (NCGs) were characterized. • Biochar holds potential for e.g. soil applications, NCGs hold potential for e.g. syngas processes. Ivory nut residues from the palm Phytelephas aequatorialis were converted via fast pyrolysis into a set of valuable biorefinery products, being (i) pyrolysis liquids rich in levomannosan and 5-hydroxymethyl furfural (5-HMF), (ii) biochar, with potential for soil applications, (iii) and non-condensable gases with potential for upgrading and syngas processes. The ivory nut residues were mannan-rich leftovers from button manufacturing in Ecuador. A handful of studies, dating back from the 20th century, have investigated gram-scale valorization of ivory nut to e.g. mannose. Nevertheless, advances in science and technology on biorefinery products called for a comprehensive reassessment of the valorization potential of this underutilized feedstock. A fully equipped, continuously operated lab-scale reactor (200 g.h−1 feed) was used for pyrolysis at 350 °C and 500 °C. The pyrolysis liquid yield was 57.53 wt% at 350 °C and 60.36 wt% at 500 °C. The aqueous phase obtained at 350 °C contained 17.5 wt% (d.b.) anhydrosugars, of which 90% was levomannosan, and contained 11.6 wt% (d.b.) furans, of which 56% was 5-HMF and 17% furfural. The carbon stability of the biochars, measured with the Edinburgh accelerated ageing tool, were 40.6% and 64.6%, respectively. Non-condensable gases during pyrolysis at 350 °C only were composed of CO 2 and CO (CO 2 :CO molar ratio of 4:1), while at 500 °C, gases were obtained with a CO 2 :CO:H 2 :CH 4 molar ratio of 9:9:4:1. Overall, the results demonstrate that pyrolysis of ivory nut holds potential as starting point for valuable biorefinery products. [ABSTRACT FROM AUTHOR]

Abstract Lignin-rich digested stillage as a novel feedstock for biochar production was subjected to slow pyrolysis. The lignin residue stemmed from a lignocellulosic ethanol pilot run with poplar, from which the stillage was anaerobically digested prior to pyrolysis. Pyrolysis conditions were optimized to meet guidelines put forth by the International Biochar Initiative and the European Biochar Certificate (molar H/C org ratio < 0.7 and O/C org ratio < 0.4), as biochar could be carbon-negative upon soil amendment, while reallocating nutrients to the field. Bench-scale pyrolysis of the lignin residue and straw were conducted according to a 33 factorial design with center runs (ranges: 370–450 °C highest treatment temperature, 5–45 min holding time and 5–50 °C.min−1 heating rate). Parametric and nonparametric statistics revealed that the highest treatment temperature was by far the most influencing factor for both feedstocks which 'pushed' H/C and O/C ratios within the desired range. Lignin-based biochar can be obtained with 50.7% yield, a H/C ratio of 0.70 and an O/C ratio of 0.20, already at 384 °C. This is considerably better when compared to straw-based biochar with identical H/C and O/C ratios, which came with a lower yield (33.7%) and required a modestly higher temperature (410 °C). Results from this study emphasize the feasibility to integrate slow pyrolysis in a lignocellulosic biorefinery. Graphical abstract Image 1 Highlights • Lignin residue from digested stillage was pyrolysed to biochar for the first time. • Temperature, heating rate and holding time were varied in a 33 factorial design. • Statistical models were used for process optimization to meet biochar standards. • The quality-quantity trade-off during pyrolysis was assessed. • At 384 °C, lignin-biochar with H/C = 0.7 and O/C = 0.2 is obtained with 50.71% yield. [ABSTRACT FROM AUTHOR]

The absorption spectrum of 13 CH 4 is recorded in the center of the tetradecad near 1.73 μm (5695–5850 cm −1 ) at 296 K and 80 K by direct absorption spectroscopy (DAS). The achieved noise equivalent absorption of the spectra is α min  ≈ 5 × 10 −8  cm −1 leading to line intensity detectivity threshold on the order of 5 × 10 −26 and 5 × 10 −27  cm/molecule at 296 K and 80 K, respectively. As a result, two empirical line lists are constructed including about 3350 and 2070 lines at room temperature and liquid nitrogen temperature, respectively. For comparison, the HITRAN database provides in the region only the strongest 13 CH 4 lines (about 440 lines in total). From the intensity ratios of the lines measured at the two temperatures, 1529 empirical values of the lower state energy level ( E emp ) were derived. Their accuracy is reflected by the clear propensity of the corresponding empirical values of the lower state rotational quantum number, J emp , to be close to integer values. They provide accurate temperature dependence for 91% and 99% of the total 13 CH 4 absorption in the region at 296 K and 80 K, respectively. The comparison to the TheoReTS ab initio line list shows significant deviations for line positions. The obtained experimental data will be valuable to tune ab initio line positions to empirical values in future versions of the theoretical line lists. [ABSTRACT FROM AUTHOR]

This work pioneers the thermocatalytic conversion of tagua seeds (or ivory nut) from the palm Phytelephas aequatorialis into key chemical building blocks, being levoglucosenone, furfural and levomannosan. Annually, ca. 100,000 metric ton of those seeds are produced in Ecuador. Mannan (a mannose-polymer similar to cellulose) is the main constituent in tagua. Thermocatalytic conversions were first explored on analytical scale to see if – and to which extent – e.g., levoglucosenone, was obtained from tagua, using catalysts with proven activity for cellulose conversion, being H3PO4 or ZnCl2. Non-catalytic fast pyrolysis led to levomannosan as main product (33.89 wt% ± 0.24 wt%), much like levoglucosan is the main product from cellulose pyrolysis. Catalytic fast pyrolysis using H3PO4 or ZnCl2 resulted in value-added levoglucosenone (max 6.64 wt% ± 0.27 wt%) and furfural (max 13.17 wt% ± 0.66 wt%) at the expense of levomannosan (between 12 wt.%–14 wt%). Validation experiments with a continuous fast pyrolysis auger reactor were successful and led to pyrolysis liquids with e.g., 3.69 wt% levoglucosenone, using H3PO4 -infused ivory nut. Although further optimization should follow this work, the results showcased a fundamental "mannan to levoglucosenone and furfural" conversion and therefore the potential of mannan-rich feedstock for biorefining. Moreover, these results can be translated to other mannan-rich agricultural residues, like açaí seeds, which are a major residue in Brazil (1.1 million metric ton annually). [Display omitted] • Mannan-rich tagua was demonstrated a valuable biorefinery feedstock. • Tagua was converted to levoglucosenone and furfural with H 3 PO 4 and ZnCl 2 , resp. • Analytical experiments were successfully translated to mini-plant scale experiments. • The biorefinery potential of mannan-rich ivory nut has been showcased. [ABSTRACT FROM AUTHOR]

In this paper we compare water vapor mixing ratio measurements from two quasi-parallel flights of the Pico-SDLA H2O and FLASH-B hygrometers. The measurements were made on 10 February 2013 and 13 March 2012, respectively, in the tropics near Bauru, São Paulo state, Brazil during an intense convective period. Both flights were performed as part of a French scientific project, TRO-Pico, to study the impact of the deep-convection overshoot on the water budget. Only a few instruments that permit the frequent sounding of stratospheric water vapor can be flown within smallvolume weather balloons. Technical difficulties preclude the accurate measurement of stratospheric water vapor with conventional in situ techniques. The instruments described here are simple and lightweight, which permits their low-cost deployment by non-specialists aboard a small weather balloon. We obtain mixing ratio retrievals which agree above the coldpoint tropopause to within 1.9 and 0.5% for the first and second flights, respectively. This level of agreement for balloonborne measured stratospheric water mixing ratio constitutes one of the best agreement reported in the literature. Because both instruments show similar profiles within their combined uncertainties, we conclude that the Pico-SDLA H2O and FLASH-B data sets are mutually consistent. [ABSTRACT FROM AUTHOR]

In this paper we compare water vapor mixing ratio measurements from two quasi-parallel flights of the Pico-SDLA H2O and FLASH-B hygrometers. The measurements were made on 10 February 2013 and 13 March 2012, respectively, in the tropics near Bauru, São Paulo state, Brazil during an intense convective period. Both flights were performed as part of a French scientific project, TRO-Pico, to study the impact of the deep-convection overshoot on the water budget. Only a few instruments that permit the frequent sounding of stratospheric water vapor can be flown within small-volume weather balloons. Technical difficulties preclude the accurate measurement of stratospheric water vapor with conventional in situ techniques. The instruments described here are simple and lightweight, which permits their low-cost deployment by non-specialists aboard a small weather balloon. We obtain mixing ratio retrievals which agree above the cold-point tropopause to within 1.9 and 0.5 % for the first and second flights, respectively. This level of agreement for balloon-borne measured stratospheric water mixing ratio constitutes one of the best agreement reported in the literature. Because both instruments show similar profiles within their combined uncertainties, we conclude that the Pico-SDLA H2O and FLASH-B data sets are mutually consistent. [ABSTRACT FROM AUTHOR]

Classical iterative methods for tomographic reconstruction include the class of Algebraic Reconstruction Techniques (ART). Convergence of these stationary linear iterative methods is however notably slow. In this paper we propose the use of Krylov solvers for tomographic linear inversion problems. These advanced iterative methods feature fast convergence at the expense of a higher computational cost per iteration, causing them to be generally uncompetitive without the inclusion of a suitable preconditioner. Combining elements from standard multigrid (MG) solvers and the theory of wavelets, a novel wavelet-based multi-level (WMG) preconditioner is introduced, which is shown to significantly speed-up Krylov convergence. The performance of the WMG-preconditioned Krylov method is analyzed through a spectral analysis, and the approach is compared to existing methods like the classical Simultaneous Iterative Reconstruction Technique (SIRT) and unpreconditioned Krylov methods on a 2D tomographic benchmark problem. Numerical experiments are promising, showing the method to be competitive with the classical Algebraic Reconstruction Techniques in terms of convergence speed and overall performance (CPU time) as well as precision of the reconstruction. [ABSTRACT FROM AUTHOR]

This work aims at a critical assessmentof properties predictingor extracting information on the density and structure of liquids.State-of-the-art NVT and NpT molecular dynamics (MD) simulations havebeen performed on five liquids: methanol, chloroform, acetonitrile,tetrahydrofuran, and ethanol. These simulations allow the computationof properties based on first principles, including the equilibriumdensity and radial distribution functions (RDFs), characterizing theliquid structure. Refinements have been incorporated in the MD simulationsby taking into account basis set superposition errors (BSSE). An extendedBSSE model for an instantaneous evaluation of the BSSE correctionshas been proposed, and their impact on the liquid properties has beenassessed. If available, the theoretical RDFs have been compared withthe experimentally derived RDFs. For some liquids, significant discrepancieshave been observed, and a profound but critical investigation is presentedto unravel the origin of these deficiencies. This discussion is focusedon tetrahydrofuran where the experiment reveals some prominent peakscompletely missing in any MD simulation. Experiments providing informationon liquid structure consist mainly of neutron diffraction measurementsoffering total structure factors as the primary observables. The splittingof these factors in reciprocal space into intra- and intermolecularcontributions is extensively discussed, together with their sensitivityin reproducing correct RDFs in coordinate space. [ABSTRACT FROM AUTHOR]

Abstract: PSII antenna size heterogeneity has been intensively studied in the past. Based on DCMU fluorescence rise kinetics, multiple types of photosystems with different properties were described. However, due to the complexity of fluorescence signal analysis, multiple questions remain unanswered. The number of different types of PSII is still debated as well as their degree of connectivity. In Chlamydomonas reinhardtii we found that PSIIα possesses a high degree of connectivity and an antenna 2–3 times larger than PSIIβ, as described previously. We also found some connectivity for PSIIβ in contrast with the majority of previous studies. This is in agreement with biochemical studies which describe PSII mega-, super- and core-complexes in Chlamydomonas. In these studies, the smallest unit of PSII in vivo would be a dimer of two core complexes hence allowing connectivity. We discuss the possible relationships between PSIIα and PSIIβ and the PSII mega-, super- and core-complexes. We also showed that strain and medium dependent variations in the half-time of the fluorescence rise can be explained by variations in the proportions of PSIIα and PSIIβ. When analyzing the state transition process in vivo, we found that this process induces an inter-conversion of PSIIα and PSIIβ. During a transition from state 2 to state 1, DCMU fluorescence rise kinetics are satisfactorily fitted by considering two PSII populations with constant kinetic parameters. We discuss our findings about PSII heterogeneity during state transitions in relation with recent results on the remodeling of the pigment-protein PSII architecture during this process. [Copyright &y& Elsevier]

The long-term stability of biochar in soil is key for carbon capture and storage and soil amelioration. Yet, its assessment is hampered by the long time-horizons needed to actually probe biochar's stability. Therefore, quick and reliable estimation methods are sought. Analytical pyrolysis (Py-GC-MS) offers a quick tool to predict biochar's stability in soil, if adequate and validated metrics can be extracted from it. This work derives and validates stability scores from biochar pyrograms and advanced data analysis. The stability scores were benchmarked by comparison with other stability metrics (Edinburgh stability tool, fixed carbon content and atomic H/C ratio). Calibration of the stability scores with these stability metrics had an R 2 between 0.61 and 0.95; validation resulted in R 2 between 0.59 and 0.72. Overall, this work illustrates how Py-GC-MS can lead to simple and adequate predictors of biochar stability. [Display omitted] • Stability Scores derived from Py-GC-MS can probe the stability of biochar in soil. • Py-GC-MS and principal component analysis were combined to set up Stability Scores. • Stability scores were selected by comparison alternative stability metrics. • Stability scores were calibrated with max R2 of 0.95. • Stability scores were validated with max R2 of 0.72. [ABSTRACT FROM AUTHOR]

Like a majority of photosynthetic microorganisms, the green unicellular alga Chlamydomonas reinhardtii may encounter O2 deprived conditions on a regular basis. In response to anaerobiosis or in a respiration defective context, the photosynthetic electron transport chain of Chlamydomonas is remodeled by a state transition process to a conformation that favours the photoproduction of ATP at the expense of reductant synthesis. In some unicellular green algae including Chlamydomonas, anoxia also triggers the induction of a chloroplast-located, oxygen sensitive hydrogenase, which accepts electrons from reduced ferredoxin to convert protons into molecular hydrogen. Although microalgal hydrogen evolution has received much interest for its biotechnological potential, its physiological role remains unclear. By using specific Chlamydomonas mutants, we demonstrate that the state transition ability and the hydrogenase function are both critical for induction of photosynthesis in anoxia. These two processes are thus important for survival of the cells when they are transiently placed in an anaerobic environment. [ABSTRACT FROM AUTHOR]

The main goal of this article is to unravel the social distribution of childcare policies: Who benefits from government investment in public childcare? The analysis complements earlier research on the distribution of social policy outcomes and confronts the growing concern over selectivity. By nature, childcare services tend to be used mainly by people in work, i.e. those in higher income brackets. Concern therefore arises about the consequences of increasing childcare budgets for the overall distribution of the benefits of social policy. This relates to the immediate outcome of social policy (net family income), but also to its increasingly central component: labour market participation. Indeed, if childcare actually benefits ‘labour market insiders’ only, one may wonder whether it is effective as an instrument activating mothers with young children. In this contribution, we look into the distributional impact of subsidized childcare for two countries (Flanders/Belgium and Sweden) already reaching the Barcelona targets for under 3s and interpret the results in a European perspective. Although both cases report high coverage rates, we find that Sweden and Flanders have different – even opposite – distributional outcomes. Both examples provide us with valuable lessons on the redistributive nature of ‘new risk policies’ and the effectiveness of childcare as an instrument of labour market activation. [ABSTRACT FROM PUBLISHER]

Abstract: Theoretical and experimental IR data are combined to gain insight into the methanol and ethanol conversion over an acidic H-SAPO-34 catalyst. The theoretical simulations use a large finite cluster and the initial physisorption energy of both alcohols is calculated. Dispersive contributions turn out to be vital and ethanol adsorbs stronger than methanol with approximately 14kJmol−1. Calculated IR spectra of the alcohols and of formed aromatic cations upon conversion are also analyzed and support the peak assignment of the experimental in situ DRIFT spectra, in particular for the C–H and Cs. Theoretical IR spectra of the gas phase compounds are compared with those of the molecules loaded in a SAPO cluster and the observed shifts of the peak positions are discussed. To get a better understanding of these framework–guest interactions, a new theoretical procedure is proposed based on a normal mode analysis. A cumulative overlap function is defined and enables the characterization of individual peaks as well as induced frequency shifts upon adsorption. [Copyright &y& Elsevier]

Hydrogen photoproduction by eukaryotic microalgae results from a connection between the photosynthetic electron transport chain and a plastidial hydrogenase. Algal H2 production is a transitory phenomenon under most natural conditions, often viewed as a safety valve protecting the photosynthetic electron transport chain from overreduction. From the colony screening of an insertion mutant library of the unicellular green alga Chlamydomonas reinhardtii based on the analysis of dark-light chlorophyll fluorescence transients, we isolated a mutant impaired in cyclic electron flow around photosystem I (CEF) due to a defect in the Proton Gradient Regulation Like1 (PGRL1) protein. Under aerobiosis, nonphotochemical quenching of fluorescence (NPQ) is strongly decreased in pgrl1. Under anaerobiosis, H2 photoproduction is strongly enhanced in the pgrl1 mutant, both during short-term and long-term measurements (in conditions of sulfur deprivation). Based on the light dependence of NPQ and hydrogen production, as well as on the enhanced hydrogen production observed in the wild-type strain in the presence of the uncoupling agent carbonyl cyanide p -trifluoromethoxyphenylhydrazone, we conclude that the proton gradient generated by CEF provokes a strong inhibition of electron supply to the hydrogenase in the wild-type strain, which is released in the pgrl1 mutant. Regulation of the trans -thylakoidal proton gradient by monitoring pgrl1 expression opens new perspectives toward reprogramming the cellular metabolism of microalgae for enhanced H2 production. [ABSTRACT FROM AUTHOR]

We report on quartz Optically Stimulated Luminescence (OSL) dating of the infill of 14 relict sand wedges and composite-wedge pseudomorphs at 5 different sites in Flanders, Belgium. A laboratory dose recovery test indicates that the single-aliquot regenerative-dose (SAR) procedure is suitable for our samples (measured to a given dose ratio 0.980 ± 0.005; n=139). Completeness of resetting of the wedge infill of two samples was confirmed by single-grain analyses. The suite of optical ages indicates that repeated thermal contraction cracking, degradation and infilling with wind-blown sediment appear to have been commonplace in Flanders during the Late Pleniglacial (Oxygen Isotope Stage 2; OIS2); more specifically, around the Last Glacial Maximum (LGM, ∼21 kyr ago) and the transition period between the LGM and the start of the Lateglacial (∼15 kyr ago). Optical dating at one site has revealed two significantly older wedge levels, the younger inset into the older; the younger wedge has an age of 36 ± 4 kyr (Middle Pleniglacial; OIS3), the older wedge 129 ± 11 kyr, which points to formation during the Late Saalian (OIS6). Our OSL ages of the wedges and host sediments bracket formation of the BGB (Beuningen Gravel Bed: a widespread deflation horizon in northwestern Europe) at between ∼15 and 18 kyr; this is in good agreement with previous OSL dating studies. We conclude that optical dating using quartz SAR OSL establishes an absolute chronology for these periglacial phenomena and allows secure palaeoenvironmental reconstructions to be made. [ABSTRACT FROM AUTHOR]

In this article we characterise the well-being of young children in the Belgian region of Flanders. We focus on three commonly used indicators: educational attainment, the existence of special needs and the occurrence of problematic behaviour. The former derives from a relatively impartial source, the schooling system, while the latter two originate from parental assessment. Somewhat surprisingly, the different measures are only weakly associated with each other. Moreover, negative outcomes tend to correlate with different characteristics of the child and the household, depending on the well-being indicator used. Only a low level of education of the mother and the fact the child is living in a single parent family is consistently associated with negative outcomes. This is not true, however, for a whole range of other characteristics, like the work schedule of the parents, the sex of the child, the child’s rank in the line of siblings or the number of children in the household. Consequently, policy makers should be wary of quick conclusions when presented with results from single indicator research. Educational lagging, for example, may seem a very objective measure of problems, yet it does not necessarily coincide with problematic behaviour nor a parental perception of special needs. Hence, political action is not self-evident and may require additional justification. For future research, a more thorough investigation about the links between the various indicators of child well-being seems indicated. [ABSTRACT FROM AUTHOR]

Under conditions of iron limitation, Pseudomonas aeruginosa secretes a high-affinity siderophore pyoverdine to scavenge Fe(lll) in the extracellular environment and shuttle it into the cell. Uptake of the pyoverdine-Fe(lll) complex is mediated by a specific outer-membrane receptor protein, FpvA (ferripyoverdine receptor). Three P. aeruginosa siderovars can be distinguished, each producing a different pyoverdine (type I-III) and a cognate FpvA receptor. Growth of an fpvA mutant of P. aeruginosa PAO1 (type I) under iron-limiting conditions can still be stimulated by its cognate pyoverdine, suggesting the presence of an alternative uptake route for type I ferripyoverdine. In silico analysis of the PAO1 genome revealed that the product of gene PA4168 has a high similarity with FpvA. Inactivation of PA4168 (termed fpvB) in an fpvA mutant totally abolished the capacity to utilize type I pyoverdine. The expression of fpvB is induced by iron limitation in Casamino acids (CAA) and in M9-glucose medium, but, unlike fpvA, not in a complex deferrated medium containing glycerol as carbon source. The fpvB gene was also detected in other P. aeruginosa isolates, including strains producing type II and type III pyoverdines. Inactivation of the fpvB homologues in these strains impaired their capacity to utilize type I ferripyoverdine as a source of iron. Accordingly, introduction of fpvB in trans restored the capacity to utilize type I ferripyoverdine. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa produces, under conditions of iron limitation, a high-affinity siderophore, pyoverdine (PVD), which is recognized at the level of the outer membrane by a specific TonB-dependent receptor, FpvA. So far, for P. aeruginosa, three different PVDs, differing in their peptide chain, have been described (types I-III), but only the FpvA receptor for type I is known. Two PVD-producing P. aeruginosa strains, one type II and one type III, were mutagenized by a mini-TnphoA3 transposon. In each case, one mutant unable to grow in the presence of the strong iron chelator ethylenediaminedihydroxyphenylacetic acid (EDDHA) and the cognate PVD was selected. The first mutant, which had an insertion in the pvdE gene, upstream of fpvA, was unable to take up type II PVD and showed resistance to pyocin S3, which is known to use type II FpvA as receptor. The second mutant was unable to take up type III PVD and had the transposon insertion in fpvA. Cosmid libraries of the respective type II and type III PVD wild-type strains were constructed and screened for clones restoring the capacity to grow in the presence of PVD. From the respective complementing genomic fragments, type II and type III fpvA sequences were determined. When in trans, type II and type III fpvA restored PVD production, uptake, growth in the presence of EDDHA and, in the case of type II fpvA, pyocin S3 sensitivity. Complementation of fpvA mutants obtained by allelic exchange was achieved by the presence of cognate fpvA in trans. All three receptors posses an N-terminal extension of about 70 amino acids, similar to FecA of Escherichia coli, but only FpvAI has a TAT export sequence at its N-terminal end. [ABSTRACT FROM AUTHOR]

Describes a Pseudomonas aeruginosa mutant with an increased susceptibility to vanadium. Strains and transposon mutagenesis; Mutagenesis by allelic exchange; Measurement of siderophore and pyocyanine production.

The standard testing procedures lot seasonal unit roots developed so far have been based mainly on time-invariant autoregressive integrated moving average (ARIMA) processes with AR polynomials involving seasonal differencing. One attractive alternative is to use periodic ARMA models. Convenient procedures are presented for testing for the presence of unit roots at the zero and seasonal frequencies in periodic time series. The limiting distributions are derived and tabulated, and simulation evidence illustrates the advantages of allowing for periodically. The tests are illustrated via applications to macroeconomic and ozone level data. [ABSTRACT FROM AUTHOR]

Several economists, notably Plosser (1978), Sargent (1978), and Wallis (1978) refuted the assumption that the seasonal component of endogenous variables in a dynamic economic model has almost all of its power restricted to what is termed seasonal frequency and its harmonics. In this article, a model with a closed-form solution is formulated to provide more insight into the arguments put forward by economists. It is concluded that univariate seasonal adjustment cannot be considered a harmless simplification of data without loss of information, neither for the interpretation of economic time series nor for regression analysis. [ABSTRACT FROM AUTHOR]

This work presents a continuous set-up for SCWO, which was operated at mild conditions (380 °C, 25 MPa, oxidant equivalence ratio of 2.0 and residence time of 26 s) to oxidize cellulose, lignin, and acetic acid as model compounds. The aim was to oxidize different organics consecutively to near completion in the same mild reaction conditions and set-up. These conditions can overcome some drawbacks associated to SCWO. To combine near complete oxidation with the applied mild process conditions, aqueous effluent from SCWO, containing intermediates from incomplete oxidation, was recycled for consecutive oxidation. Meanwhile, fresh feedstock was continuously fed to retain the process capacity. Upon recycling the aqueous effluent three to four times, depending on the feedstock, the oxidation efficiency increased from 63.9%, 45.3% and 28.3% in a single pass for cellulose, lignin, and acetic acid, respectively, to near 100%. The principle of effluent recirculation should allow a compact set-up to perform almost complete oxidation of different organics at mild conditions. The principles and effects of effluent recirculation are outlined, as well as practical consequences and perspectives of this novel principle to SCWO. • Supercritical water oxidation (SCWO) was performed at mild conditions. • Effluent recirculation was applied to improve organic oxidation efficiency. • The oxidizing capacity and oxygen consumption were favorable for recirculation. • A single and small setup at constant conditions oxidized different organics. [ABSTRACT FROM AUTHOR]

Introduction: Prolonged intense exercise has often been associated with the impairment of right ventricular (RV) function after activity, whereas this is rare for the left ventricle (LV). The effect of prolonged exercise on the heart has not been adequately measured during exercise itself. Methods: We performed real-time cardiac magnetic resonance imaging at rest and during incremental exercise in 14 male endurance athletes (mean ± SD; age = 36 ± 6 yr, BMI = 23.1 ± 1.94 kg•m−1) 1-3 wk before (baseline) and immediately after a 150-km cycling event (end-of-race) to measure LV and RV end-diastolic and end-systolic volumes (EDV and ESV), ejection fraction (EF), and ventricular-arterial coupling (stroke volume [SV]/ESV). Results: End-of-race RV EDV was unchanged from baseline at rest but was significantly increased during near-maximal exercise (235 ± 18 vs 217 ± 24 mL, P < 0.0001). Resting RV ESV was higher end-of-race (100 ± 16 vs 93 ± 15 mL, P = 0.009), which became more appreciable during near-maximal exercise (75 ± 15 vs 60 ± 14 mL, P < 0.0001). RV EF, although unchanged at rest, was significantly decreased during near-maximal exercise (68% ± 5% vs 73% ± 4%, P = 0.001). LV volume measures were similar at baseline and end-of-race. Therefore, the effect of endurance activity on the RV and LV was significantly different (P < 0.0001). Cardiac output increased to similar values at near-maximal exertion before and at the end of the race. However, whereas LV SV/ESV was unchanged, RV SV/ESV was attenuated end-of-race (P = 0.02 for interaction with race setting). Conclusions: Intense endurance exercise does not affect LV volume or function but results in RV dilatation and reduced RV EF, which becomes even more significant during exercise. Alterations in RV ventricular-arterial coupling suggest that this may be an expression of exercise-induced RV contractile impairment rather than changes in autonomic or loading conditions. [ABSTRACT FROM AUTHOR]

We present a novel method for graph partitioning, based on reinforcement learning and graph convolutional neural networks. Our approach is to recursively partition coarser representations of a given graph. The neural network is implemented using SAGE graph convolution layers, and trained using an advantage actor critic (A2C) agent. We present two variants, one for finding an edge separator that minimizes the normalized cut or quotient cut, and one that finds a small vertex separator. The vertex separators are then used to construct a nested dissection ordering to permute a sparse matrix so that its triangular factorization will incur less fill-in. The partitioning quality is compared with partitions obtained using METIS and SCOTCH, and the nested dissection ordering is evaluated in the sparse solver SuperLU. Our results show that the proposed method achieves similar partitioning quality as METIS, SCOTCH and spectral partitioning. Furthermore, the method generalizes across different classes of graphs, and works well on a variety of graphs from the SuiteSparse sparse matrix collection. [ABSTRACT FROM AUTHOR]

Abstract: The relative contributions of the PSII-dependent and Nda2-dependent pathways for H2 photoproduction were investigated in the green microalga Chlamydomonas reinhardtii after suphur-deprivation. For this purpose, H2 gas production was compared for wild-type and Nda2-deficient cells with or without DCMU (a PSII-inhibitor) in the same experimental conditions. Nda2-deficiency caused a 30% decrease of the maximal H2 photoevolution rate observed shortly after the establishment of anoxia, and an acceleration of the decline of H2 photoevolution rate with time. DCMU addition to Nda2-deficient cells completely inhibited H2 photoproduction, showing that the PSII-independent H2 photoproduction relies on the presence of Nda2, which feeds the photosynthetic electron transport chain with electrons derived from oxidative catabolism. Nda2-protein abundance increased as a result of sulphur deprivation and further during the H2 photoproduction process, resulting in high rates of non-photochemical plastoquinone reduction in control cells. Nda2-deficiency had no significant effect on photosynthetic and respiratory capacities in sulphur-deprived cells, but caused changes in the cell energetic status (ATP and NADPH/NADP+ ratio). The rapid decline of H2 photoevolution rate with time in Nda2-deficient cells revealed a more pronounced inhibition of H2 photoproduction by accumulated H2 in the absence of non-photochemical plastoquinone reduction. Nda2 is therefore important for linking H2 photoproduction with catabolism of storage carbon compounds, and seems also involved in regulating the redox poise of the photosynthetic electron transport chain during H2 photoproduction. [Copyright &y& Elsevier]

The article presents information on the Fang ancestral sculpture of Equatorial Africa. Since the beginning of the twentieth century, Fang ancestral sculpture of Equatorial Africa figured among the most emblematic and esteemed genres of African art. These anthropomorphic effigies, with an often haphazardly oozing black patina, of upright posture and subtle craftsmanship, were mounted on sewn-bark relic boxes containing the remains, including the skulls, of lineal ancestors. Every family had one or more. Honored and often consulted during rites of propitiation or of divination, these sculptures and the skulls they magically protected constituted the basic wealth of the Fang peoples of the past, a source of welfare, strength, and social power.

• 24 biochar samples from 12 different feedstocks were characterised using five different chemical characterization methods. • Five feedstock independent indicators were identified based on the principal component analysis. • The highest treatment temperature was modelled using three feedstock-independent indicators. • The multilinear model and auxiliary correlations were positively validated with external datasets. Besides the feedstock composition, the highest treatment temperature (HTT) in pyrolysis is one of the key production parameters. The latter determines the feedstock's carbonization extent, which influences physicochemical properties of the resulting biochar, and in consequence its performance in industrial and agricultural applications. The actual HTT of biomass is difficult to measure in a reliable manner in many large-scale pyrolysis units (e.g., rotary kilns). Therefore, producers and end-users often rely on unreliable or biased information regarding this key production parameter that affects biochar quality. Data from indirect chemical assessment methods of biochar's carbonization extent correlate well with the highest treatment temperature. Therefore, this study demonstrates that the HTT can be accurately assessed posteriori and feedstock-independently via a simple-to-use model based on biochar characteristics related to the carbonization extent. For that purpose, 24 contrasting biochars from 12 different feedstocks produced in the most common production temperature range of 350−700 °C were analysed using 5 different established biochar chemical characterization methods. Then, experimental data was used to establish a multilinear regression model capable of correlating the HTT, which was successfully validated for external datasets. The correlation accuracy for biochars of various origin (lignocellulosic, manure) was satisfactorily high (R2adj. = 0.853, RSME =47 °C). The obtained correlation proved that the HTT can be predicted feedstock independently with the use of basic input data. It also provides a quick, simple, and reliable tool to verify the HTT of a given biochar. [ABSTRACT FROM AUTHOR]

Protein phosphorylation plays important roles in short-term regulation of photosynthetic electron transfer, and during state transitions, the kinase STATE TRANSITION7 (STT7) of Chlamydomonas reinhardtii phosphorylates components of light-harvesting antenna complex II (LHCII). This reversible phosphorylation governs the dynamic allocation of a part of LHCII to PSI or PSII, depending on light conditions and metabolic demands, but counteracting phosphatase(s) remain unknown in C. reinhardtii. Here we analyzed state transitions in C. reinhardtii mutants of two phosphatases, PROTEIN PHOSPHATASE1 and PHOTOSYSTEM II PHOSPHATASE, which are homologous to proteins that antagonize the state transition kinases (STN7 and STN8) in Arabidopsis (Arabidopsis thaliana). The transition from state 2 to state 1 was retarded in pph1, and surprisingly also in pbcp. However, both mutants eventually returned to state 1. In contrast, the double mutant pph1;pbcp appeared strongly locked in state 2. The complex phosphorylation patterns of the LHCII trimers and of the monomeric subunits were affected in the phosphatase mutants. Their analysis indicated that the two phosphatases have different yet overlapping sets of protein targets. The dual control of thylakoid protein dephosphorylation and the more complex antenna phosphorylation patterns in C. reinhardtii compared to Arabidopsis are discussed in the context of the stronger amplitude of state transitions and the more diverse LHCII isoforms in the alga. [ABSTRACT FROM AUTHOR]

A flexible Integrated Bayesian Multi-model Uncertainty Estimation Framework (IBMUEF) is presented to simultaneously quantify conceptual model structure, input and parameter uncertainty of a groundwater flow model. In this fully Bayesian framework, the DiffeRential Evolution Adaptive Metropolis (DREAM) algorithm with a novel likelihood function is combined with Bayesian Model Averaging (BMA). Four alternative conceptual models, representing different geological representations of an overexploited aquifer, have been developed. The uncertainty of the input of the model is represented by multipliers. A novel likelihood function based on a new heteroscedastic error model is included to extend the applicability of the framework. The results of the study confirm that neglecting conceptual model structure uncertainty results in unreliable prediction. Consideration of both model structure and input uncertainty are important to obtain confident parameter sets and better model predictions. This study shows that the IBMUEF provides more reliable model predictions and accurate uncertainty bounds. • Full Bayesian multi-model approach to quantify uncertainty of MODFLOW model. • Simultaneously quantifies model structure, input and parameter uncertainty. • DREAM with a novel likelihood function is combined with BMA. • Neglecting conceptual model uncertainty results in unreliable prediction. • Results in more reliable model predictions and accurate uncertainty bounds. [ABSTRACT FROM AUTHOR]

This article presents a low-rank decomposition algorithm based on subsampling of matrix entries. The proposed algorithm first computes rank-revealing decompositions of submatrices with a blocked adaptive cross approximation (BACA) algorithm, and then applies a hierarchical merge operation via truncated singular value decompositions (H-BACA). The proposed algorithm significantly improves the convergence of the baseline ACA algorithm and achieves reduced computational complexity compared to the traditional decompositions such as rank-revealing QR. Numerical results demonstrate the efficiency, accuracy, and parallel scalability of the proposed algorithm. [ABSTRACT FROM AUTHOR]

This study outlines the effect of citric acid leaching on the quality and stability of fast pyrolysis bio-oils from sugarcane bagasse (SCB) and sugarcane trash (SCT). The quality of bio-oil was probed by GC-MS analysis, elemental composition, higher heating value, water and solids content, pH, dynamic viscosity and stability (ageing). Pyrolysis was performed at 500 °C in a fully controlled, continuously operated plant with a biomass throughput of ca. 300 g.hr−1. While citric acid leaching causes a decrease of the average bio-oil yield with 5%, it does not lead to a bio-oil with improved fuel-related properties. However, the bio-oil composition became more advantageous in light of its biorefining. Indeed, citric acid leaching led to an increased levoglucosan concentration – a promising platform chemical – of 17% for SCB and of to 35% for SCT (based on relative abundance in GC-MS). In tandem, the concentration of carboxylic acids and phenols in the bio-oil decreased after citric acid leaching, which is beneficial for downstream purification of levoglucosan. Regarding the non-condensable gases, CO and CO 2 represented between 88% and 91% by weight of the total non-condensable gases produced in pyrolysis. Therefore, the results of this study demonstrate that optimized biomass demineralization pretreatment with citric acid could produce bio-oil at high yield and rich in high-value chemical compounds like levoglucosan. Biomass demineralization pretreatment however, does not result in bio-oil with improved quality for fuel purposes, nor does it necessarily lead to bio-oil having higher stability. • Mild pretreatment with CA is effective in ash removal in sugarcane residues. • CA pretreated feedstock has higher bio-oil yields on pretreated feedstock basis. • Fresh/aged trash derived bio-oils have lower viscosity than bagasse derived bio-oils. • CA pretreatment holds no major benefit for bio-oil composition in terms of fuel use. • Major increase in anhydrosugar content after mild CA pretreatment of sugarcane residues. [ABSTRACT FROM AUTHOR]

Over recent years, pyrolysis has grown into a mature technology with added value for producing soil improvers. Further innovations of this technology lie in developing tailor-made products from specific feedstocks (or mixtures thereof) in combination with adjusted mixing ratio-temperature regimes. In this context, co-pyrolysis of pig manure (PM) and the invasive plant Japanese knotweed (JK) at different mixture ratios (w/w) of 3:1 (P3J1), 1:1 (P1J1), and 1:3 (P1J3) and varying temperatures (400–700 °C) was studied to address the low carbon properties and heavy metals (HMs) risks of manure-derive biochars and beneficially ameliorate the bio-invasion situation by creating value from the plant biomass. Co-pyrolysis of PM with JK increased by nearly 1.5 folds the fixed carbon contents in the combined feedstock biochars obtained at 600 °C compared with PM-derived biochar alone, and all combined feedstock biochars met the requirements for soil improvement and carbon sequestration. The total HMs in PM biochars were significantly reduced by adding JK. The combined feedstock biochar P1J1 generated at 600 °C was the most effective in transforming Cu and Zn into more stable forms, accordingly reducing the associated environmental risk of heavy metal leaching from the biochar. In addition, the accumulation of macronutrients can be an added benefit of the co-pyrolysis process, and P1J1-600 was also the biochar that retained the most nutrients (P, Ca, Mg, and K). [Display omitted] • Japanese knotweed addition improved the aromaticity of pig manure-derived biochar. • Co-pyrolysis reduced total Cu and Zn compared to pig manure-derived biochar. • Cu and Zn transformed to stable forms reduce the environmental risk of the biochar. • Co-pyrolysis retained higher nutrients than Japanese knotweed-derived biochar alone. • A 1:1 ratio of pig manure to Japanese knotweed at 600 °C was the optimal condition. [ABSTRACT FROM AUTHOR]

In photosynthetic eukaryotes, nonphotochemical plastoquinone (PQ) reduction is important for the regulation of photosynthetic electron flow. In green microalgae where this process has been demonstrated, the chloroplastic enzyme that catalyses nonphotochemical PQ reduction has not been identified yet. Here, we show by an RNA interference (RNAi) approach that the NDA2 gene, belonging to a type II NAD(P)H dehydrogenases family in the green microalga Chlamydomonas reinhardtii, encodes a chloroplastic dehydrogenase that functions to reduce PQ nonphotochemically in this alga. Using a specific antibody, we show that the Nda2 protein is localized in chloroplasts of wild-type cells and is absent in two Nda2-RNAi cell lines. In both mutant cell lines, nonphotochemical PQ reduction is severely affected, as indicated by altered chlorophyll fluorescence transients after saturating illumination. Compared with wild type, change in light excitation distribution between photosystems ('state transition') upon inhibition of mitochondrial electron transport is strongly impaired in transformed cells because of inefficient PQ reduction. Furthermore, the amount of hydrogen produced by Nda2-RNAi cells under sulfur deprivation is substantially decreased compared with wild type, which supports previous assumptions that endogenous substrates serve as source of electrons for hydrogen formation. These results demonstrate the importance of Nda2 for nonphotochemical PQ reduction and associated processes in C. reinhardtii. [ABSTRACT FROM AUTHOR]

Bacteria with intrinsic resistance to antibiotics are a worrisome health problem. It is widely believed that intrinsic antibiotic resistance of bacterial pathogens is mainly the consequence of cellular impermeability and activity of efflux pumps. However, the analysis of transposon-tagged Pseudomonas aeruginosa mutants presented in this article shows that this phenotype emerges from the action of numerous proteins from all functional categories. Mutations in some genes make P. aeruginosa more susceptible to antibiotics and thereby represent new targets. Mutations in other genes make P. aeruginosa more resistant and therefore define novel mechanisms for mutation-driven acquisition of antibiotic resistance, opening a new research field based in the prediction of resistance before it emerges in clinical environments. Antibiotics are not just weapons against bacterial competitors, but also natural signalling molecules. Our results demonstrate that antibiotic resistance genes are not merely protective shields and offer a more comprehensive view of the role of antibiotic resistance genes in the clinic and in nature. [ABSTRACT FROM AUTHOR]