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Soil erosion is a common problem worldwide, and in Durango, Mexico, it occurs in 77.4% of territory. Faced with this problem, the hydrological keyline design (HKD) is an alternative that helps to retain soil, increase infiltration, and keep the water uniformly in the land in order to recover its fertility. The objective of this research was to evaluate the effect of HKD on moisture and soil conservation in a rainfed agricultural plot during the spring–summer 2018 cycle with a bean crop (Phaseolus vulgaris L.) in the state of Durango, Mexico. Two treatments were established: control and HKD. The variables to measure the effect of the treatments were: soil water content, water erosion, bean yield, and yield components. The results indicated differences (p < 0.05) between treatments for the moisture and erosion variables; the HKD retained more water than the control by five percent, while sediment transport was lower in the HKD. No differences (p > 0.05) were found regarding bean yield and yield components. However, the yield was 126% higher than regional average in terms of rainfed bean production. Therefore, the implementation of the HKD had a positive impact by retaining soil and moisture.

In this report, physical and chemical properties, and total arsenic (As) concentrations were analyzed in agricultural (MASE) and mining soils (SMI) in the State of Guanajuato, México. Additionally, a metagenomic analysis of both types of soils was the bases for the identification and selection of bacteria and fungi resistant to As. The SMI soil showed higher concentration of As (39 mg kg −1 ) as compared to MASE soil (15 mg kg −1 ). The metagenome showed a total of 175,240 reads from both soils. MASE soil showed higher diversity of bacteria, while the SMI soil showed higher diversity of fungi. 16S rRNA analysis showed that the phylum Proteobacteria showed the highest proportion (39.6% in MASE and 36.4% in SMI) and Acidobacteria was the second most representative (24.2% in SMI and 11.6% in MASE). 18S rRNA analysis, showed that the phylum Glomeromycota was found only in the SMI soils (11.6%), while Ascomycota was the most abundant, followed by Basidiomycota, and Zygomycota, in both soils. Genera Bacillus and Penicillium were able to grow in As concentrations as high as 5 and 10 mM, reduced As (V) to As (III), and removed As at 9.8% and 12.1% rates, respectively. When aoxB , arsB, ACR3(1), ACR3(2,) and arrA genes were explored, only the arsB gene was identified in Bacillus sp., B. simplex , and B. megaterium . In general, SMI soils showed more microorganisms resistant to As than MASE soils. Bacteria and fungi selected in this work may show potential to be used as bioremediation agents in As contaminated soils.

The forest ecosystems of Mexico experience soil degradation mainly due to water erosion, which causes low vegetation regeneration. One of the strategies to diminish soil loss is through the construction of stone bunds (SB)—hand-made structures to trap sediment and store water for longer periods. However, little is known about their effects on pine establishment. The objectives of this study were to evaluate the effect of SB on the survival and growth of individual P. engelmannii Carr. specimens with respect to the distance of their planted. The study additionally sought to analyse how SB would affect changes in the production of aerial phytomass, herbaceous vegetation cover and soil characteristics in a reforested area of Durango State in north-central Mexico. Three treatments were evaluated by planting pine trees at three distances with respect to the SB: 80 cm upslope bund (UB), 80 cm downslope bund (DB) and between upper and lower bunds (BB). The variables analysed were the following: The survival and growth of reforestation, aerial coverage and the production of herbaceous plants, and the physicochemical characteristics of the soil. Survival showed significant differences (p < 0.05) among treatments, UB (80%), DB (27%) and BB (30%). The production of aerial phytomass did not show significant differences between treatments UB (1651 kg ha−1) and DB (1058 kg ha−1), although these two were different (p < 0.05) to BB (600 kg ha−1). On the other hand, the vegetation cover and soil characteristics did not show statistical differences. These results highlight the importance of the effect of SB on the survival of P. engelmannii Carr. and the growth of herbaceous vegetation.

Peter Zumthor’s work underwent a pivotal shift in the mid-1980s that changed its reason for being. Under the decisive influence of certain contemporary art movements, it turned into what some have called architectural minimalism or, in its most extreme form, the «zero degree» of architecture. Its emergence has been attributed to an architectural reinterpretation of a linguistic degré zéro based in forms and principles of Conceptual art and Minimal art of the 1960s. The evolution of the zero degree that Zumthor explicitly applied in the Topography of Terror in Berlin and the Steilneset Memorial in Vardø suggests that he may have found his zero condition of architecture in earlier roots. A review of the concept and both projects reveals echoes of Malevich’s Suprematism and Russian Constructivism, to approach some of the keys to Zumthor’s transition toward a phenomenological realism. La obra de Peter Zumthor experimentó una transformación radical a mediados de los 1980s participando en una recherche architecturale desarrollada en la Suiza del Norte. Algunos movimientos del arte contemporáneo tuvieron un efecto determinante en lo que se denominó el minimalismo arquitectónico o, su versión más extrema, el grado cero de la arquitectura. Su aparición ha sido atribuida a la reinterpretación arquitectónica de un degré zéro lingüístico apoyado en formas del arte minimal y del arte conceptual de los 1960s. La evolución del grado cero que Zumthor aplicó explícitamente en la Topografía del Terror en Berlín y el Steilneset Memorial en Vardø sugiere que pudo encontrar su condición cero de la arquitectura en raíces anteriores. Una revisión del concepto y de ambos proyectos permite descubrir ecos del suprematismo de Malevitch y del constructivismo ruso para acercarse a algunas de las claves de la transición de Zumthor hacia un realismo fenomenológico. A obra de Peter Zumthor experimentou unha transformación radical a mediados dos 1980s participando nunha recherche architecturale desenvolvida na Suíza do Norte. Algúns movementos da arte contemporáneo tiveron un efecto determinante no que se denominou o minimalismo arquitectónico ou, a súa versión máis extrema, o grao cero da arquitectura. A súa aparición foi atribuída á reinterpretación arquitectónica dun degré zéro lingüístico apoiado en formas da arte minimal e da arte conceptual do 1960s. A evolución do grao cero que Zumthor aplicou explicitamente na Topografía do Terror en Berlín e o Steilneset Memorial en Vardø suxire que puido atopar a súa condición cero da arquitectura en raíces anteriores. Unha revisión do concepto e de ambos os proxectos permite descubrir ecos do suprematismo de Malevitch e do constructivismo ruso para achegarse a algunhas das claves da transición de Zumthor cara a un realismo fenomenológico.

The existence of fecal coliform microorganisms (FCs) resistant to antibiotics in the domestic wastewater of an urban and semi-urban locality was determined, along with the effect of two types of treatment plants for wastewater on the resistance of coliform, an aerated lagoon (AL) and a stabilization lagoon (SL). Samples were taken from the affluent and effluent of each treatment plant. FC content, pH, electrical conductivity, dissolved oxygen, total solids, total volatile solids, and several types of ions were determined. Resistant FCs were quantified by plate count in bright green bile agar with ampicillin, amoxicillin, sulfamethoxazole-trimethoprim, amikacin, gentamicin, cefixime and their mixtures. The isolated strains were evaluated against other antibiotics using antibiograms. The relationship between the variables was validated with an analysis of variance factorial design, and Fisher’s means test (α = 0.05) and Pearson’s correlation were used to establish it. The community that presented more resistant FCs was the urban one, but when the wastewater passed through the systems of AL and SL, this fact changed. The resistance of the FCs to ampicillin, amoxicillin, trimethoprim, sulfamethoxazole and cefixime was higher in the SL, with values of 67, 48, 2 and 25.8%, while those for the AL were 20, 13, 22 and 5.3%, respectively.

La evaluación de la condición ecológica de las riberas es un elemento importante en el estudio de los ríos alrededor del mundo. El objetivo del presente trabajo fue evaluar la calidad del bosque de ribera, desde un punto de vista estructural y funcional, en un tramo de 21 kilómetros del río El Tunal en Durango, México, mediante la aplicación del índice QBR. En el tramo estudiado se evaluaron seis sitios seleccionados por su representatividad, accesibilidad y heterogeneidad de su vegetación. En general, los resultados muestran un río con indicios importantes de deterioro; se encontraron dos sitios con calidad intermedia, dos sitios presentaron calidad mala y los dos restantes presentaron calidad pésima.

La evaluación de la condición ecológica de las riberas es un elemento importante en el estudio de los ríos alrededor del mundo. El objetivo del presente trabajo fue evaluar la calidad del bosque de ribera, desde un punto de vista estructural y funcional, en un tramo de 21 kilómetros del río El Tunal en Durango, México, mediante la aplicación del índice QBR. En el tramo estudiado se evaluaron seis sitios seleccionados por su representatividad, accesibilidad y heterogeneidad de su vegetación. En general, los resultados muestran un río con indicios importantes de deterioro; se encontraron dos sitios con calidad intermedia, dos sitios presentaron calidad mala y los dos restantes presentaron calidad pésima.The assessment of the ecological condition of the river banks is an important element in the rivers study around the world. The objective of this work was to evaluate the ecological condition of the riparian forest in a transect of 21 km of El Tunal river in Mexico with the QBR index. In the transect of study six sites were evaluated which were selected by the representation, possibilities of access and the heterogeneity of the vegetation. In general, the results have shown a river with important signs of deterioration; two sites results in an intermediate quality, two sites results in bad quality and two results in poor quality.

Due to the level of reliability of information that can be obtained, as well as the simplicity and speed in implementation and because of its low cost, a quality index for riparian forests (QBR) was applied in order to characterize the ecological status of the riparian forest associated with the La Sauceda River, in Durango, Mexico. It is one of the major rivers in the San Pedro-Mezquital River basin, the most important source of fresh water for the National Wetlands Biosphere Reserve, a red focus on the conservation of Mexican biodiversity, since it is the mangroves largest and production in North America. The La Sauceda River faces major threats from plans to construct large dams and remove gallery forests. Results from this study showed a forest in poor ecological condition, demonstrating that the index is a reliable tool for hydromorphological diagnosis of rivers and riverbanks.

The assessment of the ecological condition of the river banks is an important element in the rivers study around the world. The objective of this work was to evaluate the ecological condition of the riparian forest in a transect of 21 km of El Tunal river in Mexico with the QBR index. In the transect of study six sites were evaluated which were selected by the representation, possibilities of access and the heterogeneity of the vegetation. In general, the results have shown a river with important signs of deterioration; two sites results in an intermediate quality, two sites results in bad quality and two results in poor quality. [PUBLICATION ABSTRACT]