Rational points in the moduli space of genus two

We build a database of genus 2 curves defined over $\mathbb Q$ which contains all curves with minimal absolute height $h \leq 5$, all curves with moduli height $\mathfrak h \leq 20$, and all curves with extra automorphisms in standard form $y^2=f(x^2)$ defined over $\mathbb Q$ with height $h \leq 101$. For each isomorphism class in the database, an equation over its minimal field of definition is provided, the automorphism group of the curve, Clebsch and Igusa invariants. The distribution of rational points in the moduli space $\mathcal M_2$ for which the field of moduli is a field of definition is discussed and some open problems are presented

Water quality index in the high-andean micro-basin of the Chumbao river, Andahuaylas, Apurímac, Perú

The water quality index (WQI) of a water body, indicates the degree of contamination for a given use, and it is related to the anthropic activities that they provoke around. The objective was to determine the WQI, in the high-Andean micro-basin of the Chumbao River, Andahuaylas, Peru. The section of study was included between the head of the basin (13°46'42.5" S, 73°13'50.0" W and 4 295 m of altitude), and last sampling point (13°35'26.4" S, 73°27'0.8" W and 2 529 m of altitude), with an average slope of 4%. The WQI Dinius was evaluated considering parameters such as oxygen level (DO and BOD5), eutrophication level (NO3 - and PO4 3-), physical characteristics (temperature, turbidity, color and TDS), dissolved substances (alkalinity, hardness, pH, conductivity and chlorides), and microbiological parameters (E. coli and total coliforms); it was sampled during the avenues season (02 lentic points and 08 lotics). The data were collected in triplicate, and analyzed through an ANOVA, Tukey test and Pearson's correlation at 5% significance. It was found that the predominant use of river water is for agriculture, pasture and urbanization; the WQI is divided into three categories Excellent (M1, M2, M3, M4 and M5) close to the head of the micro-basin and the lentic points (Pampahuasi and Paccoccocha lagoons), Acceptable (M6), and excessively contaminated points M7 and M8 outside the urban area downstream (p-value < 0.05); presenting a good negative correlation with the study parameters. In conclusion, the water in areas of low population density is good