Hyperspectral remote sensing of cyanobacterial pigments as indicators for cell populations and toxins in eutrophic lakes

The growth of mass populations of toxin-producing cyanobacteria is a serious concern for the ecological status of inland waterbodies and for human and animal health. In this study we examined the performance of four semi-analytical algorithms for the retrieval of chlorophyll a (Chl a) and phycocyanin (C-PC) from data acquired by the Compact Airborne Spectrographic Imager-2 (CASI-2) and the Airborne Imaging Spectrometer for Applications (AISA) Eagle sensor. The retrieval accuracies of the semi-analytical models were compared to those returned by optimally calibrated empirical band-ratio algorithms. The best-performing algorithm for the retrieval of Chl a was an empirical band-ratio model based on a quadratic function of the ratio of re!ectance at 710 and 670 nm (R2=0.832; RMSE=29.8%). However, this model only provided a marginally better retrieval than the best semi-analytical algorithm. The best-performing model for the retrieval of C-PC was a semi-analytical nested band-ratio model (R2=0.984; RMSE=3.98 mg m−3). The concentrations of C-PC retrieved using the semi-analytical model were correlated with cyanobacterial cell numbers (R2=0.380) and the particulate and total (particulate plus dissolved) pools of microcystins (R2=0.858 and 0.896 respectively). Importantly, both the empirical and semi-analytical algorithms were able to retrieve the concentration of C-PC at cyanobacterial cell concentrations below current warning thresholds for cyanobacteria in waterbodies. This demonstrates the potential of remote sensing to contribute to early-warning detection and monitoring of cyanobacterial blooms for human health protection at regional and global scales

Some relationships between wetland characteristics and mammal species richness for wetlands in southern Ontario.

In Southern Ontario, wetlands are becoming increasingly fragmented by human development, intensifying the potential for a decline in species richness. Data was collected from 27 wetlands in Southern Ontario, to assess the effects of wetland area, topographic diversity, diversity and land use of the surrounding matrix, disturbance within the wetland, and isolation of the wetland on mammal species richness. Multiple regression analyses indicated that area is the most significant influence on species richness for the total species complement, wetland specific species only, and non-wetland specific species. Topographic diversity and matrix diversity were found to be significant for the total species complement and wetland specific species, and isolation was found to be significant for wetland specific species. It was also found that a large proportion of built areas in the surrounding matrix results in reduced species richness for the wetland, while a large proportion of agricultural development results in increased wetland specific species richness. Analyses of the residuals showed that wetlands found in the Low Boreal wetland region have greater species richness than wetlands in the Eastern Temperate wetland region. It was concluded that the varying degree of development in these regions was responsible for the regional differences in species richness. Future wetland management must reflect the effects of wetland characteristics and the characteristics of the area in which the wetlands are found in order to preserve maximum species richness.Dept. of Geography. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1994 .G66. Source: Masters Abstracts International, Volume: 33-04, page: 1121. Adviser: I. Stebelsky. Thesis (M.A.)--University of Windsor (Canada), 1994

IL CONTRATTO A TEMPO INDETERMINATO A TUTELE CRESCENTI

La disciplina del licenziamento nel rapporto di lavoro ha comportato una dinamica evolutiva, che l'ha portata a distaccarsi dal regime disposto dal codice civile, incentrato, per entrambe le parti del rapporto di lavoro, sul principio, di matrice liberale, della libertà di recesso dal contratto di lavoro subordinato a tempo indeterminato. Con la Legge n. 108/1990 è stato portato a compimento una generalizzazione della giustificazione del licenziamento individuale. Una maggiore intensificazione della tutela contro i licenziamenti trova un freno, invece, con la riforma della tutela reale ad opera della Legge n. 92/2012. Questo ridimensionamento, da ultimo, viene confermato ed intensificato dalla disciplina in materia di contratto di lavoro a tempo indeterminato a tutele crescenti, di cui al D.lgs. n. 23/2015

Quantifying measures to limit wind driven resuspension of sediments for improvement of the ecological quality in some shallow Dutch lakes

Although phosphorus loadings are considered the main pressure for most shallow lakes, wind-driven resuspension can cause additional problems for these aquatic ecosystems. We quantified the potential effectiveness of measures to reduce the contribution of resuspended sediments, resulting from wind action, to the overall light attenuation for three comparable shallow peat lakes with poor ecological status in the Netherlands: Loosdrecht, Nieuwkoop, and Reeuwijk (1.8–2.7 m depth, 1.6–2.5 km fetch). These measures are: 1. wave reducing barriers, 2. water level fluctuations, 3. capping of the sediment with sand, and 4. combinations of above. Critical shear stress of the sediments for resuspension (Vcrit), size distribution, and optical properties of the suspended material were quantified in the field (June 2009) and laboratory. Water quality monitoring data (2002–2009) showed that light attenuation by organic suspended matter in all lakes is high. Spatial modeling of the impact of these measures showed that in Lake Loosdrecht limiting wave action can have significant effects (reductions from 6% exceedance to 2% exceedance of Vcrit), whereas in Lake Nieuwkoop and Lake Reeuwijk this is less effective. The depth distribution and shape of Lake Nieuwkoop and Lake Reeuwijk limit the role of wind-driven resuspension in the total suspended matter concentration. Although the lakes are similar in general appearance (origin, size, and depth range) measures suitable to improve their ecological status differ. This calls for care when defining the programme of measures to improve the ecological status of a specific lake based on experience from other lakes.

Agricultural Microcredit and Household Vulnerability in Rural Malawi

textabstractSixteen girls with Turner syndrome (TS) were treated for 4 years with biosynthetic growth hormone (GH). The dosage was 4IU/m2 body surface s.c. per day over the first 3 years. In the 4th year the dosage was increased to 61 U/m2 per day in the 6 girls with a poor height increment and in 1 girl oxandrolone was added. Ethinyl oestradiol was added after the age of 13. Mean (SD) growth velocities were 3.4 (0.9), 7.2 (1.7), 5.3 (1.3), 4.3 (2.0) and 3.6 (1.5) cm/year before and in the 1st, 2nd, 3rd and 4th year of treatment. Skeletal maturation advanced faster than usual in Turner patients especially in the youger children. Although the mean height prediction increased by 5.6 cm and 11 of the 16 girls have now exceeded their predicted height, the height of the 4 girls who stopped GH treatment exceeded the predicted adult height by only 0 to 3.4 cm

Depressive Symptoms and Amygdala Volume in Elderly with Cerebral Small Vessel Disease: The RUN DMC Study

Introduction. Late onset depressive symptoms (LODSs) frequently occur in elderly with cerebral small vessel disease (SVD). SVD cannot fully explain LODS; a contributing factor could be amygdala volume. We investigated the relation between amygdala volume and LODS, independent of SVD in 503 participants with symptomatic cerebral SVD. Methods. Patients underwent FLAIR and T1 scanning. Depressive symptoms were assessed with structured questionnaires; amygdala and WML were manually segmented. The relation between amygdala volume and LODS/EODS was investigated and adjusted for age, sex, intracranial volume, and SVD. Results. Patients with LODS had a significantly lower left amygdala volume than those without (P = 0.02), independent of SVD. Each decrease of total amygdala volume (by mL) was related to an increased risk of LODS (OR = 1.77; 95% CI 1.02–3.08; P = 0.04). Conclusion. Lower left amygdala volume is associated with LODS, independent of SVD. This may suggest differential mechanisms, in which individuals with a small amygdala might be vulnerable to develop LODS