Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

In this text we intend to interpret a good part of Edgar Morin’s work as an attempt to rethink, on the ruins of the philosophy of suspicion, the conditions of possibility of the subject and his responsibility in the construction of his future. This would be a New Humanism that responds to the challenges of globalization from an ecologized thought rooted in its bio-ecological determinations and is built on the remains of the already clearly insufficient proposals of the Cartesian dualistic reductionism of classical science and of the de- constructive fashion that delegitimizes all paradigmatic foundations.

In contrast to this prevailing scientistic thinking, one of the ideas underlying Edgar Morin’s thought is the return to humanism, which should be reconstructed in such a way that society is capable of apprehending reality in all its constituent as- pects. To this end, Morin proposes anthropoetics, as action and ethical life that takes into account anthropological aspects of the human being, in order to reconnect indi- vidual, society and species, thus including human, social and biological reality. From here, we intend to interpret the epistemo- logical reform proposed by Morin as an argument to reconstruct the social solidarities necessary to combat the threats to democratic and educational quality coming from the phenomena of disinformation and post-truth.

The complex is the impossibility of a methodological reductionism that knows the thing in a definitive way, which would require a dogmatic and scholastic attitude, where what is said in a historical moment about the thing acquires the character of definitive and timeless. Based on this conviction, this text traces a derivation of Edgar Morin’s work Introduction to Complex Thought, taking into account a series of critical considerations about some of his fundamental ideas from psychoanalysis, phenomenology and other theoretical traditions.

The search of Federico García Lorca’s bodily remains has necessarily reopened a debate over the poet’s cultural significance. The testimonial compulsion shown by many of the instigators of this search is largely rooted in an ideological unconscious marked by a factual positivism that is characteristically phenomenological, with phenomenology misconstrued as an immediate collusion between the ideal and the empirical, between Lorca as idealized symbol of Spain or the Republic and his body as the “thing” that brings about collective salvation. Through a strategy of cumulative distancings, the present article seeks to set up arguments against the convenience of bringing such unconscious back to life. I argue too in favor of the suitability of a return to the poet’s body of writing, yet a return untouched by what Husserl called “naiven Positivität”.

There are few scientific studies that explore the use of medicinal plants for snakebite envenoming in Central America, although plant-based therapies have been traditionally used in the region. This work reviews the studies conducted in Central America to assess the ability of extracts obtained from plants of local ethnomedical use to inhibit toxic activities of the venom of Bothrops asper, the snake responsible for approximately half of the snakebite envenomings in these countries. The search prioritized the description of the plants used in Guatemala since most of the studies described in this work were conducted in that country, although references to other countries are included. Information concerning secondary metabolites and other pharmacological activities of these plant species, relevant to the treatment of snakebites, was also described. The literature search was conducted in the Google Scholar, PubMed, and Scopus databases and completed with locally available literature. It was found that extracts of 12 plant species inhibited the hemorrhagic effect of the venom and three neutralized the edema-forming activity, while inhibition of proteolytic and phospholipase A2 (PLA2) activities was achieved by three and one plant species, respectively. Only Brownea rosa-de-monte was able to effectively counteract the in vitro coagulant effect of the venom. Some plant extracts screened in Guatemala demonstrated procoagulant or anti-thrombin intrinsic effects that might aggravate the coagulopathy induced by the venom. These findings underscore the need to carry out scientific studies aimed at validating the inhibitory potential of Central American plant extracts and their metabolites against B. asper venom

The hydrological network in the Lachuá Ecoregion (EL), Alta Verapaz, Guatemala, hosts high levels of biodiversity and supplies water to 44 Mayan communities. Despite this critical fact, this network has been threatened by scarcely monitored industrial activities including the rapidly expanding oil palm monoculture (Elaeis guineensis Jacq). Regardless of Lachua’s freshwaters importance, there is little information on how this monoculture impacts them. We compared water-quality properties from streams in oil palm plantations (P), paddock and milpa systems (M), and primary forests (F) in EL. During 2015-2016, 13 rivers were sampled (5 times) for water temperature, pH, dissolved oxygen (DO), conductivity, hardness, chemical and biochemical oxygen demand (COD and BOD), and concentration of silica, nitrates, phosphates, and ammonia. Several parameters showed significant differences. P were 2.7ºC and 1.8ºC warmer than M and F and carried 1.4mg/L more nitrates than F. F carried 10.8mg/L and 11.8mg/L more silica than M and P. M showed intermediate temperatures and silica concentrations, as well as 14.8µS/cm and 8.9µS/cm lower conductivities than P and F. Additionally, COD in M was 9.9mg/L and 4.6mg/L lower than P and F. We believe higher temperatures and lower silica in P are due to the loss of riparian forest and their role in buffering temperatures and recycling silicon. In addition, the existence of secondary forest (guamil) in M might explain the intermediate temperatures and silica concentrations. Our results highlight the contributions of forests to waterways and suggest potential water-quality depletion from the oil palm expansion in EL.

Metakaolin is a product of kaolin's calcination. The high pozzolanic activity of metakaolin allows its usage as supplementary cementitious material in concrete. This property and other physicochemical properties are affected by metakaolin's manufacturing conditions. Therefore, this study aims to characterize the changes in color and density of two types of kaolin (tuff and hydrothermal) through a thermogravimetric analysis of the calcination process. Evaluation of density used ASTM C188, while the assessment of color changes used a CIE-L*a*b* spectrophotometer in conjunction with normative UNE 80117. In addition, weight loss and density were correlated with the color coordinates using polynomial regression. The results showed that kaolin dehydroxylation occurred at 450ºC and 550ºC, characterized by a maximum in delta E * of 12.9 and 4.3 for hydrothermal and tuff kaolin, respectively. In addition, the tuff kaolin presented the maximum luminosity (L * = 92.84) of all the treatments at 21ºC. This value decreased 11.75% during the temperature increment up to 450ºC. From this temperature, L * increased linearly until reaching a final value of 87.3 at 900ºC. The polynomial regression explained 93% and 92% of the weight variation as a function of the CIE-L*a*b* parameters for tuff and hydrothermal kaolin, respectively.

In Guatemala, potato crop production is affected by the nematodes Globodera rostochiensis and Globodera pallida. The ability of both species to form cysts complicates their control and causes an increase in their populations. In Guatemala, both species of nematodes have been reported by morphological identification; however, molecular confirmation has not been carried out. It is the first study to validate the presence of both nematode species by multiplex PCR and determine the diversity and genetic structure of the populations using molecular markers. Sampling was carried out in four potato-producing departments of the country. PCR identification was performed with the common primer ITS5 and the primers PITSr3 specific for G. rostochiensis and PITSp4 for G. pallida. We performed molecular characterization with the AFLP marker. We confirmed the presence of the two nematode species in the four departments. Shannon diversity and expected heterozygosity indices revealed higher genetic diversity in G. rostochiensis (H = 0.311, He = 0.301) than in G. pallida (H = 0.035, He = 0.223). The NJ, DAPC, and PCA methods exhibited weak structure among populations of both nematode species. The results suggest a dispersal pattern from Quetzaltenango to the rest of the country, attributed to the commercialization of seed contaminated with nematodes. We suggest promoting socialization programs on the benefits of using certified seeds and constant molecular monitoring for an accurate diagnosis of both species of nematodes.

White cement-based mortars in urban areas are usually discolored and altered their esthetic properties due to air pollutants. The addition of nanoparticles in these mortars can provide photocatalytic properties that can decompose pollution agents. Likewise, other hydrophobic agents have been individually studied to improve outdoor building constructions. Therefore, this study presented the photocatalytic and hydrophobic effect of adding nano-TiO2 and silicone hydrophobic powder (DOWSILTM) in a white cement matrix. The nano-TiO2 were characterized by X-Ray Diffraction (XRD); afterwards, the mortar was mixed with additions of nano-TiO2 (0.0, 0.5, 1.0, 3.0%) and DOWSILTM (0.0, 0.5%). The mortar's photocatalytic performance was evaluated using a modification of the standard Italian test Ente Nazionale Italiano di Unificazione 11259:2016 based on Rhodamine B (RhB) degradation on the sample exposed to UV irradiation. Therefore, mortar samples were subjected to UV irradiation to degrade the organic dye rhodamine B, monitoring their color variation using a CIEL*a*b* spectrophotometer. Moreover, the water permeability and the contact angle were evaluated. This research demonstrates that the white cement-based mortar samples added with nano-TiO2/DOWSILTM possess photocatalytic activity. The samples with the addition of 1.0%/0.5% and 3.0%/0.5% nano-TiO2/DOWSILTM showed a higher RhB degradation for R4 and R26. Therefore, these two materials can be employed in these proportions to improve the quality of the white cement-based mortars in urban constructions.