Determining basic forest stand characteristics using airborne laser scanning in mixed forest stands of Central Europe

This study focused on the derivation of basic stand characteristics from airborne laser scanning (ALS) data, aiming to elucidate which characteristics (mean height and diameter, dominant height and diameter) are best approximated by the variables obtained using ALS data. The height of trees of different species in four permanent plots located in the Slovak Republic was derived from the normalised digital surface model (nDSM) representing the canopy surface, using an automatic approach to identify local maxima (individual treetops). Tree identification was carried out using four different spatial resolutions of the nDSM (0.5 m, 1.0 m, 1.5 m, and 2.0 m) and the number of trees identified was compared with reference data obtained from field measurements. The highest percentage of tree detection (69-75%) was observed at the spatial resolutions of 1.0 and 1.5 m. Absolute differences of tree height between reference and ALS datasets ranged from 0 to 36% at all spatial resolutions. The smallest difference in mean height was obtained using the higher spatial resolution (0.5 m), while the smallest difference in the dominant height of the relative number of thickest trees (h10% and h20%) was observed using the lower spatial resolution (2 m). The same trends also apply to diameters. The average errors at resolution of 1.0 and 1.5 m was 8.7%, 5.9% and 9.7% for mean height, h20% and h10%, respectively. ALS-derived diameters (obtained using regression models from reference data and ALS-derived individual height as predictor) showed absolute errors in the range 0-48% at all spatial resolutions. The deviation in mean diameter at a resolution of 0.5 m ranged from -12.1% to 15.3%

Electrochemistry of ring-substituted 1-hydroxynaphthalene-2-carboxanilides: Relation to structure and biological activity

Twenty-two novel antimycobacterial agents, 1-hydroxynaphthalene-2-carboxanilides, were studied by cyclic voltammetry on a glassy carbon electrode in a phosphate buffer pH 7.2 – dimethyl sulfoxide (DMSO) mixed medium (9:1; v/v). All compounds exhibited similar voltammetric behavior with one irreversible anodic signal in the range 100–300 mV corresponding to the oxidation of hydroxyl group on the naphthalene moiety. A shift of the oxidation potential was caused solely by electron donating or withdrawing effects of substituents and their position on the benzene moiety. Mechanism of oxidation in the studied medium was briefly outlined. Values of oxidation potentials exhibited very good linear correlation with calculated Hammett σ substituent constants. For all active compounds, a relationship between oxidation potentials and MIC or IC50 values obtained from in vitro screening was investigated in detail. Primary in vitro screening of synthesized compounds was previously performed against three species of Mycobacterium pathogens. Additionally, their activity related to the inhibition of photosynthetic electron transport (PET) in spinach chloroplasts was tested in previous publications. In vitro screening against Mycobacterium tuberculosis was performed here for the first time with 1-hydroxy-N-(3-trifluoromethylphenyl)naphthalene-2-carboxamide being the most effective (MIC = 11.7 μmol L−1). Furthermore, several other compounds showed higher antimycobacterial activity than the standard isoniazid. Relation of biological activities and oxidation potentials was successfully found in some cases; however, final correlations must also be considered with other physical and chemical factors contributing to the biological activity. Relation of structure, biological activity and electrochemical potential was also studied by cyclic voltammetry in cathodic area for three compounds containing reducible nitro moiety. © 2019 Elsevier Lt

Association between ambient air pollution and diabetes mellitus in Europe and north America : systematic review and meta-analysis

BACKGROUND: Air pollution is hypothesized to be a risk factor for diabetes. Epidemiological evidence is inconsistent and has not been systematically evaluated.OBJECTIVES: We systematically reviewed epidemiological evidence on the association between air pollution and diabetes, and synthesized results of studies on type 2 diabetes (T2DM).METHODS: We systematically searched electronic literature databases (last search 29 April 2014) for studies reporting the association between air pollution (particle concentration or traffic exposure) and diabetes (type 1, type 2 or gestational). We systematically evaluated risk of bias and role of potential confounders in all studies. We synthesized reported associations with T2DM in meta-analyses using random effect models and conducted various sensitivity analyses.RESULTS: We included 13 studies (eight on T2DM, two on type 1, three on gestational diabetes), all conducted in Europe or North-America. Five studies were longitudinal, five cross-sectional, two case-control and one ecologic. Risk of bias, air pollution assessment, and confounder control varied across studies. Dose-response effects were not reported. Meta-analyses of three studies on PM2.5 (particulate matter >2.5 µm in diameter) and four studies on NO2 (nitrogen dioxide) showed increased risk of T2DM by 8-10% per 10 µg/m3 increase in exposure [PM2.5: 1.10 (95% CI: 1.02, 1.18); NO2: 1.08 (95% CI: 1.00, 1.17)]. Associations were stronger in females. Sensitivity analyses showed similar results.CONCLUSION: Existing evidence indicates a positive association of air pollution and T2DM risk albeit there is high risk of bias. High quality studies assessing dose-response effects are needed. Research should be expanded to developing countries where outdoor and indoor air pollution are high