Comparative assessment of satellite- and drone-based vegetation indices to predict arthropod biomass in shrub-steppes.

Arthropod biomass is a key element in ecosystem functionality and a basic food item for many species. It must be estimated through traditional costly field sampling, normally at just a few sampling points. Arthropod biomass and plant productivity should be narrowly related because a large majority of arthropods are herbivorous, and others depend on these. Quantifying plant productivity with satellite or aerial vehicle imagery is an easy and fast procedure already tested and implemented in agriculture and field ecology. However, the capability of satellite or aerial vehicle imagery for quantifying arthropod biomass and its relationship with plant productivity has been scarcely addressed. Here, we used unmanned aerial vehicle (UAV) and satellite Sentinel-2 (S2) imagery to establish a relationship between plant productivity and arthropod biomass estimated through ground-truth field sampling in shrub steppes. We UAV-sampled seven plots of 47.6-72.3 ha at a 4-cm pixel resolution, subsequently downscaling spatial resolution to 50 cm resolution. In parallel, we used S2 imagery from the same and other dates and locations at 10-m spatial resolution. We related several vegetation indices (VIs) with arthropod biomass (epigeous, coprophagous, and four functional consumer groups: predatory, detritivore, phytophagous, and diverse) estimated at 41-48 sampling stations for UAV flying plots and in 67-79 sampling stations for S2. VIs derived from UAV were consistently and positively related to all arthropod biomass groups. Three out of seven and six out of seven S2-derived VIs were positively related to epigeous and coprophagous arthropod biomass, respectively. The blue normalized difference VI (BNDVI) and enhanced normalized difference VI (ENDVI) showed consistent and positive relationships with arthropod biomass, regardless of the arthropod group or spatial resolution. Our results showed that UAV and S2-VI imagery data may be viable and cost-efficient alternatives for quantifying arthropod biomass at large scales in shrub steppes. The relationship between VI and arthropod biomass is probably habitat-dependent, so future research should address this relationship and include several habitats to validate VIs as proxies of arthropod biomass.

Intensity profile during an ultra-endurance triathlon in relation to testing and performance.

We examined the heart rate (HR)-based intensity profile during an ultra-endurance triathlon (UET) estimated from the individual HR-oxygen uptake (˙VO2) relationship during specific graded tests, relating it to race performance. 9 male ultra-endurance triathletes completed the study. Before racing, subjects performed graded exercise tests involving cycle (C) ergometry, treadmill running (R) and free swimming (S) for peak ˙VO2 and HR at ventilatory thresholds (VT). Exercise-specific HR-˙VO2 regression equations were developed. Mean race HR was higher during S (149.2 (10.1) bpm) than during C (137.1 (5.7) bpm) and R (136.2 (10.5) bpm). During C and R, HR was below both VT (11% and 27-28%). HR differences between S and C correlated with C, R and final times. The greatest differences between S and C were related to the worst times in the next stages. These ultra-endurance triathletes performed S at a higher relative intensity, which was inversely correlated with performance in the following stages. The best predictors of final racing time (81%) were weight-adjusted ˙VO2max and HR difference between C and S. A more adequate characterization of the time pattern during the whole race, especially during S, adds new information concerning the intensity profile and cardiovascular demands of an UET race.

Perceived exertion, time of immersion and physiological correlates in synchronized swimming.

This study examined the relationship between ratings of perceived exertion (RPE, CR-10), heart rate (HR), peak blood lactate (La peak), and immersion (IM) parameters in 17 elite synchronized swimmers performing 30 solo and duet routines during competition. All were video recorded (50 Hz) and an observational instrument was used to time the IM phases. Differences in the measured variables were tested using a linear mixed-effects model. RPE was 7.7 ± 1.1 and did not differ among routines, and neither did any of the HR parameters. There were differences among routines in La peak (F3,7=16.5; P=0.002), number of IM (F3,15=14.0; P<0.001), total time immersed (F3,16=26.6; P<0.001), percentage of time immersed (F3,13=6.5; P=0.007) and number of IM longer than 10 s (F3,19=3.0; P=0.04). RPE correlated positively to HR pre-activation, range of variation and recovery, IM parameters and La peak, and inversely to minimum and mean HR. A hierarchical multiple linear regression (MLR) model (number of IM >10 s, HR recovery, minimum HR, and La peak) explained 62% RPE variance (adj. Rm 2=0.62; P<0.001). A stepwise MLR model (La peak, mean IM time and pre-exercise HR) explained 46% of performance variance (adj. Rm 2=0.46; P<0.001). Findings highlight the psycho-physical stress imposed by the combination of intense dynamic exercise with repeated and prolonged apnea intervals during SS events.

Ultrasound and radiology surrogate endpoints in pharmacological studies.

Cardiovascular studies investigating therapeutic intervention with clinical endpoints are costly due to the need for considerable duration and large number of patients, or both. Therefore, for evaluation of novel cardiovascular drug efficacy, surrogate endpoints are used. Cardiovascular imaging endpoints have proven their worth. Sometimes the relevance of imaging is questioned and other methods are suggested instead. There is also some confusion about the strengths of imaging endpoints. The aim of the present paper is to review ultrasound and radiology imaging techniques as surrogate endpoints in pharmacological trials.

Prediction of preterm birth using the cervical consistency index.

OBJECTIVES: To assess the diagnostic power of a new cervical consistency index (CCI) obtained using transvaginal sonography for the prediction of spontaneous preterm birth (PTB) and to establish reference ranges for this new variable. METHODS: Included in this prospective cross-sectional study were 1115 singleton pregnancies at 5-36 weeks of gestation. Anteroposterior cervical diameter was measured before (AP) and after (AP') application of pressure on the cervix using the transvaginal probe. The index was calculated using the formula: CCI=((AP'/AP) × 100). Cervical length was also measured. The outcomes evaluated were spontaneous PTB before 32, 34 and 37 weeks. Logistic regression and analysis of receiver-operating characteristics (ROC) curves were performed to evaluate the diagnostic power of CCI and cervical length (adjusted for gestational age). Intraclass correlation coefficients (ICCs) and Bland-Altman analysis were used to evaluate intra- and interobserver variability. RESULTS: In the 1031 women with follow-up, the rate of spontaneous PTB before 32 weeks was 0.87%, before 34 weeks was 2.13% and before 37 weeks was 7.76% (n=80). There were 31 (3.01%) iatrogenic PTBs before 37 weeks. An inverse linear correlation between gestational age and CCI was observed, with regression equation: CCI (in %)=89.8 - 1.35 × (GA in weeks); r(2)=0.66, P<0.001. Cervical length showed an inverse quadratic, though non-significant, relationship with gestational age: CL (in mm)=31.084 - 0.0278× (GA in weeks)(2) + 1.0772× (GA in weeks); r(2)=0.076, P<0.14. The intra- and interobserver ICCs for CCI were 0.99 (95% CI, 0.988-0.994) and 0.98 (95% CI, 0.973-0.987), respectively. The area under the ROC curve for CCI in the prediction of spontaneous PTB before 32 weeks was 0.947, for spontaneous PTB before 34 weeks it was 0.943 and for spontaneous PTB before 37 weeks it was 0.907. For a 5% screen-positive rate, CCI had a sensitivity of 67%, 64% and 45% for prediction of spontaneous PTB before 32, 34 and 37 weeks, respectively, with equivalent values of 11%, 9% and 11% for cervical length. CONCLUSIONS: CCI shows a clear inverse linear relationship with GA. Assessment of CCI is reproducible and is effective in the prediction of spontaneous PTB. This new variable appears to provide better prediction of spontaneous PTB than does cervical length.

Simple and double emulsions via coaxial jet electrosprays.

We report for the first time the generation of electrified coaxial jets of micrometric diameter in liquid media. Scaling laws to predict the inner and outer diameter of the coaxial jet are given. We show some experiments illustrating the formation process of the coaxial jet, and demonstrate how this process can be used to yield either o/w (oil in water) or o/w/o (oil/water/oil) emulsions of micrometric size. Some interesting analogies with other hydrodynamic focusing processes are also pointed out.

Antibacterial diterpenoids from Cedrus atlantica.

Four diterpene alcohols were isolated from the neutral hexane extract of the cones of Cedrus atlantica, and their structures were confirmed after comparing their spectral data with literature values. These products exhibited significant antibacterial activity against gram (+/-) bacteria.

Germacranolides from Anvillea radiata.

The aerial parts of Anvillea radiata yielded a new germacranolide, 8alpha,9alpha-epoxyparthenolide (3), together with two known compounds, 9alpha-hydroxyparthenolide (1) and parthenolid-9-one (2). The structures of the compounds were elucidated from IR, HRMS, 1H and 13C-NMR, COSY, HETCOR, HMBC and HOHAHA spectral data. The major component 1 was tested for its cytotoxicity and antibacterial activity.

An experimental study of the electrospraying of water in air at atmospheric pressure.

Water solutions with electrical conductivities ranging from that of the deionized water up to 2 S/m have been electrosprayed in air through narrow silica tubes. Results show unambiguously that steady cone jets of water in air without the assistance of glow discharge can be formed for the range of electrical conductivities we have explored. The absence of corona discharge has been proven not only for the good agreement between the experimental results and the scaling laws given in the cone-jet literature but also for the independence of the spray current on the atmosphere (air or CO(2)) in which water was being electrosprayed. Other regimes such as the electric dripping and the assisted glow discharge cone-jet mode that appear in the electrospraying of water in air at room temperature have also been investigated.

Steady cone-jet electrosprays in liquid insulator baths.

This study shows that conducting liquids can be electrosprayed in steady cone-jet mode inside liquid insulator baths. Experimental results show that the current emitted from the meniscus fits well the scaling laws given in the literature for electrosprays in air at atmospheric pressure or vacuum. The technique may be of interest in obtaining fine liquid-liquid emulsions of uniformly sized droplets in the nanometric range.

Improved GA1 production by Fusarium fujikuroi.

Recent studies into gibberellin A(1) (GA(1)) showed it to be physiologically more active than GA(3) in plants of great agricultural interest, such as tomatoes, rice, peas, and sweet cherries. We describe here a simple procedure for obtaining large quantities of GA(1) (1,500 mg/l) by incubating the FKMC1995 strain of Fusarium fujikuroi in a standard complex medium (SCM). We also compare the GA production of this strain with that of two other wild-type strains of F. fujikuroi (IMI58289, m567) in SCM and low-nitrogen medium and discuss the possible biogenetic mechanisms involved in the over-accumulation of GA(1) by FKMC1995.

Self-rotation in electrocapillary flows.

The mechanism of appearance of swirl in a certain class of converging flows is investigated numerically. The analysis is motivated by the spontaneous generation of swirl, which has been observed in electrified menisci (Taylor cones). The electrical stress acting on the cone surface drives these electrified millimetric fluid flows. Numerical results show that the primarily swirl-free meridian flow is unstable within an interval of values of the Reynolds number based on the surface stress. For values of the Reynolds number outside this interval, which depends on the forcing conditions and the geometry of the flow, the nonswirling meridian flow is stable. The instability mechanism of circulation amplification, which has nothing to do with the well-known increase of swirl velocity due to the vortex stretching mechanism, is due to a convection-diffusion effect. The circulation accumulated at the axis zone by the converging meridian motion is pumped by diffusion toward the conical surface. This feedback loop mechanism shoots the circulation amplification for values of the Reynolds number larger than a critical one. The same instability mechanism of swirl amplification could also appear in other converging flows generated by body forces (natural convection, electrical forces, etc.).

Micro/nano encapsulation via electrified coaxial liquid jets.

We report a method to generate steady coaxial jets of immiscible liquids with diameters in the range of micrometer/nanometer size. This compound jet is generated by the action of electro-hydrodynamic (EHD) forces with a diameter that ranges from tens of nanometers to tens of micrometers. The eventual jet breakup results in an aerosol of monodisperse compound droplets with the outer liquid surrounding or encapsulating the inner one. Following this approach, we have produced monodisperse capsules with diameters varying between 10 and 0.15 micrometers, depending on the running parameters.

Atividade antibacteriana de furanoeliangólidos / Antibacterial activity of furanoeliangolides

As lactonas sesquiterpênicas licnofólido (1) e eremantólido C (2) e alguns derivados: 1 ,2 -epóxieremantólido C (3), 1 β -hidróxi-2,3-diidroeremantólido C (4), 3 - hidróxieremantólido C (5), cloreto de 4,5-diidroeremantólido-5-n-propilamônio (6) e 1 β -hidróxi- 2,3-diidrolicnofólido (7) foram testadas contra as bactérias Enterococus faecalis S48, Bacillus subtilis CECT 397, Staphylococus aureus ATCC 8, Salmonella typhymurium LT2, Escherichia coli U9 e Proteus sp. Os compostos 1, 4, 5 e 7 apresentaram atividade antibacteriana.

Sesquiterpene lactones lychnopholide (1) and eremantholide C (2) and some derivatives: 1 ,2 -epoxyeremantholide C (3), 1 β -hidroxy-2,3-dihydroeremantolide C (4), 3 -hydroxyeremantholide C (5), 5-n- propylamonium- 4,5-dihydroeremantholide C chloride (6) and 1 β -hydroxy-2,3- dihydrolychnopholide (7) were tested against Enterococus faecalis S48, Bacillus subtilis CECT 397, Staphylococus aureus ATCC 8, Salmonella typhymurium LT2, Escherichia coli U9 e Proteus sp. Compounds 1, 4, 5 and 7 showed activity.

Microbial transformation of ent-kaurenoic acid and its 15-hydroxy derivatives by the SG138 mutant of Gibberella fujikuroi.

Feeding experiments with ent-kaurenoic acid (4), 15 alpha-hydroxy-ent-kaurenoic acid (5), 15 beta-hydroxy-ent-kaurenoic acid (6), and mixtures of 4 plus 5 and 4 plus 6 were conducted using the SG138 mutant of Gibberella fujikuroi, to gain information about the phenotype of this unique strain. The biotransformation of 5 gave 7 beta,15 alpha-dihydroxykaurenolide (9) and 7 beta,15 alpha-dihydroxy-ent-kaurenoic acid (13). The incubation of 6 produced 7 beta,15 beta-dihydroxy-ent-kaurenoic acid (7) and 7 beta,15 beta-dihydroxykaurenolide (10). No 15-hydroxylated gibberellins were detected in any of these experiments. The results indicated that a hydroxy group at C-15 does not inhibit 7 beta-hydroxylase activity but in the SG138 strain obstructs the enzymatic ring-B contraction of ent-kaurenoids to gibberellins. Exogenous 4 stimulated both the excretion of ent-kaurene and the fungal metabolism of 5 and 6.

Approach to the synthesis of antitumor quassinoids from labdane diterpenes: an efficient synthesis of a picrasane-related intermediate.

[structure: see text]. The tetracyclic ketal 24, a suitable intermediate for the synthesis of antitumor pentacyclic quassinoids, has been efficiently prepared from communic acids (5a-c), via methyl ketone 9. The synthetic sequence from 9 to 24 consists of 15 steps in 12% overall yield.