1. We assessed the distribution of scaled chrysophytes in fresh waters along 3200 km of the east coast of North America (29 to 48 N) to determine any biogeographic patterns in relation to chemical, physical, climatic and spatial variables. 2. Scaled chrysophytes were identified using scanning electron microscopy and counted from 264 waterbodies in nine regions (20 subregions). Eighteen chemical...

Many analytical problems involve measurement of a large number of experimental variables on a set of samples. Unfortunately, some of them can deteriorate the performance of classification models because not all variables yield the same quality and quantity of information. In this paper four strategies to perform variable selection in mid-infrared spectral data using genetic algorithms (GAs) are...

Data from spectrophotometers form spectra that are sets of a great number of exploitable variables in quantitative chemical analysis; calibration models using chemometric methods must be established to exploit these variables. In order to design these calibration models which are specific to each analyzed parameter, it is advisable to select a reduced number of spectral variables. This paper pr...

The water quality and phytoplankton of Ufiobodo Ebonyi River reservoirs were studied for nine months from March to November, 2019 evaluate the suitability domestic supply habitat aquatic organisms. Temperature, pH, conductivity, total dissolved solid (TDS), transparency, oxygen (DO) depth measured in situ, while samples collected determination nitrate, iron, silicate phosphate laboratory. Phyto...