Diversity of vam in soils used to cultivate sugarcane (Saccharum spp.) in Tabasco, Mexico

E Objective: A study was carried out in the Ingenio Santa Rosalía sugar mill supply area with the aim of identifying the soil subunits cultivated with sugar cane and to quantify the degree of mycorrhization of Saccharum officinarum. Design/Methodology/Approach: Rhizosphere samples were collected at a depth of 0-30 cm and root segments with diameters of ≤ 1 mm and 1-2.0 mm were studied. The intersect method and the fungal structures method were comparatively analyzed to determine the mycotrophic state of the roots. The study also quantified the number of spores in the soils and classified the morpho-species of vesicular-arbuscular mycorrhiza (VAM). Results: The results show that seven soil subunits exist in the area, but the intersect method did not detect differences in colonization by root diameter or by root colonization ( = 68.5%). For its part, the fungal structures method showed differences in colonization between soil subunits ( = 69.5%), being higher in thin roots, and statistical differences wer found for vesicles and spores. At the sites, an average of 696 spores was quantified per 100 g of soil, which indicates a high presence of vesicular-arbuscular mycorrhizal fungi in the study area. Finally, six species of mycorrhizae were identified, of which four are present in various soil subunits: Glomus aff. deserticola, Glomus etunicatum, Glomus viscosum, and Paraglomus occultum. Study Limitations/Implications: This was an exploratory study that indicates the potential of VAM. Findings/Conclusions: The presence of hyphae, vesicles, arbuscules, and spores indicates that there is an active mycotrophic process between VAM and sugarcane cultivation in the soils of the study area.

Feeding habits of the spotted rose snapper, Lutjanus guttatus, (Actinopterygii, Perciformes, Lutjanidae), in the central Gulf of California, BCS, Mexico

The spotted rose snapper, Lutjanus guttatus (Steindachner, 1869), is an important resource for the coastal fisheries of the Gulf of California, mainly due to its high commercial value. Despite this, there are no management measures for this species, owing in part to a lack of information on its basic biology and its trophic ecology in the area. In this context, the presently reported study had as objective to describe the feeding habits of L. guttatus through stomach content analyses, as well as to describe possible changes linked to sex, size, and season. Specimens were caught monthly from June 2016 to September 2017 with gillnets in Santa Rosalía, BCS, Mexico. The abundance, weight, and frequency of occurrence of each prey were assessed, and these parameters were integrated into the index of relative importance (%IRI) to determine the importance of each prey item in the L. guttatus diet. The Levin’s index was used to assess the trophic niche width of the species, the feeding strategy was evaluated using Costello’s graphic method and the trophic level was calculated. Finally, to establish whether there were significant differences in the diet by sex, size, or season a PERMANOVA test was used with a 95% confidence level. A total of 202 L. guttatus stomachs were analyzed, 191 of which contained food. A total of 26 prey items were identified. According to the %IRI, the most important prey were the teleost fishes Harengula thrissina (Jordan et Gilbert, 1882) (45.7%) and Sardinops sagax (Jenyns, 1842) (34.8%), the euphausiid Nyctiphanes simplex (13.4%), and the crustacean Penaeus spp. (5.6%). The PERMANOVA analysis resulted in significant differences between the analyzed categories; however, there were no significant differences in the interactions among the categories. According to Levin’s index, L. guttatus had a narrow trophic width, with changes in the main prey consumed by the different categories. According to our results, L. guttatus can be considered a benthopelagic opportunistic carnivorous predator with a narrow trophic niche, presenting mostly quantitative variations in its diet according to sex, size, and season. Its trophic plasticity allows it to take advantage of the most available and abundant food resources.

Analysis of the industrial quality of three sugarcane cultivars at “santa rosalía de la chontalpa” sugarcane mill

Objective: To evaluate the industrial quality of three sugarcane cultivars in a template cycle at the supply area of “Santa Rosalía de la Chontalpa” sugarcane mill. Design / Methodology / Approach: An experiment was established under a factorial design 3x3 (3 cultivars: CP 72-2086, MEX 79-431 and MEX 69-290; x 3 sampling dates: 330, 390 and 450 DDS, Spanish equivalent for days after sowing) on an Eutric Fluvisol soil. In each plantation, a sample of 10 stems with three replications was collected to determine the industrial quality by polarimetry. Results: The industrial quality of the evaluated cultivars only differed statistically in terms of the percentage of purity, MEX 79-431 was the one that presented the lowest value for this variable. At 450 DDS, the highest value was observed for °Brix (17.28), POL percentage (14.92), purity (86.44%). The values obtained in the present study for the quality of juice in the evaluated cultivars are within the range of the standard values established for Mexico. Limitations / Implications: Polarimetry is still the method used by most of the sugar mills in Mexico, even if other more environmental-friendly methodologies exist. Findings / Conclusions: The trend line that best fit to MEX 69-290 and MEX 79-431, for °Brix, POL and purity, was a linear polynomial and to CP 72-2086, a polynomial quadratic. Fresh stems and reducing sugars showed best fit with an inverse polynomial. °Brix presented strong and positive correlation with POL (R = 0.99**); and strong and negative with reducer sugars (R = -0.95**) and fresh stem humidity (R = -0.91**).

Supplemental Material: Volcanic record of the arc-to-rift transition onshore of the Guaymas basin in the Santa Rosalía area, Gulf of California, Baja California

Item S1: Analytical methods, including XRF and ICP-MS whole-rock geochemical analysis, ⁴⁰Ar-³⁹Ar geochronological analytical methods, and zircon isotopic methods. Item S2: Excel spreadsheet of whole-rock geochemical data, including XRF and LA-ICPMS data. Item S3: ⁴⁰Ar-³⁹Ar geochronological data: Summary table, and data tables and plots for each sample. Item S4: U-Pb zircon data. Item S5. Hf-isotope zircon data. Item S6: Outcrop photos. Item 7: Photomicrographs, including examples of all samples dated by ⁴⁰Ar-³⁹Ar. Item S8: Summary of published definitions of adakites and high magnesium andesites. Item S9: KMZ files for geologic maps.

Supplemental Material: Volcanic record of the arc-to-rift transition onshore of the Guaymas basin in the Santa Rosalía area, Gulf of California, Baja California

Item S1: Analytical methods, including XRF and ICP-MS whole-rock geochemical analysis, ⁴⁰Ar-³⁹Ar geochronological analytical methods, and zircon isotopic methods. Item S2: Excel spreadsheet of whole-rock geochemical data, including XRF and LA-ICPMS data. Item S3: ⁴⁰Ar-³⁹Ar geochronological data: Summary table, and data tables and plots for each sample. Item S4: U-Pb zircon data. Item S5. Hf-isotope zircon data. Item S6: Outcrop photos. Item 7: Photomicrographs, including examples of all samples dated by ⁴⁰Ar-³⁹Ar. Item S8: Summary of published definitions of adakites and high magnesium andesites. Item S9: KMZ files for geologic maps.

Prototipo generador de energía "AKS" como una idea emprendedora en Santa Rosalía, Baja California Sur

This article shows the results obtained from the market study that was carried out in the community of Santa Rosalia, Baja California Sur, in order to know the tastes, preferences and opinions of consumers about the “AKS” energy generating prototype , which is an exercise bike that is connected to a 12-volt battery and when pedaling on it, energy is generated by means of a generator motor, so that everything produced is stored in the battery and from there with the help of an inverter the current is taken out, with the intention of reducing the consumption of electric energy, what is paid for it and pollution in the environment. where an exploratory-descriptive investigation was used, in order to obtain the results, analyze them and then carry them out for the improvement of the prototype, all this through different tools, such as, survey, interviews to establishments and direct observation. So with the results obtained, they were able to see the answers of how to create a product that fully meets their expectations and that manages to generate large sales and obtain a good market positioning.

Use of office package of free software in high school of Santa Rosalía, BCS

The present article shows the results of the study carried to the junior high schools of Santa Rosalía Baja California Sur, to identify the level of knowledge that the students and teachers have about the free office software package, where the result obtained was a high percentage of ignorance. It should be noted the great availability and acceptance shown by students and teachers towards this software package based on free software. To carry out this study, it was used the exploratory and descriptive methods, where the study sample was a total of 135 students and 44 teachers who replied the surveys and interviews, which were conducted in two stages: the first one, was carried out to know the level of knowledge the school community has about of office programs of free software; the second one, was done to know the level of acceptance of it.

Trabajo y salud en el mineral de Santa Rosalía, Baja California Sur, durante el régimen porfiriano

El presente trabajo tiene como objetivo estudiar la relación trabajo-salud en el mineral de Santa Rosalía durante la época porfiriana. Un pueblo que fue conformado por la compañía francesa El Boleo al parejo del desarrollo de la explotación cuprífera, con la observación de que en esta última se aplicó la tecnología más avanzada en ese entonces en el mundo occidental, mientras el pueblo careció de la infraestructura sanitaria más indispensable, como era la introducción del agua potable y drenaje. Ello conllevó a una situación permanente de insalubridad que junto con la dureza de las condiciones laborales devinieron diversas enfermedades que la postre desencadenaron en altos índices de mortalidad.