El Pedregal Research Articles

Genomic Characterization of a Dog-Mediated Rabies Outbreak in El Pedregal, Arequipa, Peru.

Rabies, a re-emerging zoonosis with the highest known human case fatality rate, has been largely absent from Peru, except for endemic circulation in the Puno region on the Bolivian border and re-emergence in Arequipa City in 2015, where it has persisted. In 2021, an outbreak occurred in the rapidly expanding city of El Pedregal near Arequipa, followed by more cases in 2022 after nearly a year of epidemiological silence. While currently under control, questions persist regarding the origin of the El Pedregal outbreak and implications for maintaining rabies control in Peru. We sequenced 25 dog rabies virus (RABV) genomes from the El Pedregal outbreak (n=11) and Arequipa City (n=14) from 2021-2023 using Nanopore sequencing in Peru. Historical genomes from Puno (n=4, 2010-2012) and Arequipa (n=5, 2015-2019), were sequenced using an Illumina approach in the UK. In total, 34 RABV genomes were analyzed, including archived and newly obtained samples. The genomes were analyzed phylogenetically to understand the outbreak's context and origins. Phylogenomic analysis identified two genetic clusters in El Pedregal: 2021 cases stemmed from a single introduction unrelated to Arequipa cases, while the 2022 sequence suggested a new introduction from Arequipa rather than persistence. In relation to canine RABV diversity in Latin America, all new sequences belonged to a new minor clade, Cosmopolitan Am5, sharing relatives from Bolivia, Argentina, and Brazil. Genomic insights into the El Pedregal outbreak revealed multiple introductions over a 2-year window. Eco-epidemiological conditions, including migratory worker patterns, suggest human-mediated movement drove introductions. Despite outbreak containment, El Pedregal remains at risk of dog-mediated rabies due to ongoing circulation in Arequipa, Puno, and Bolivia. Human-mediated movement of dogs presents a major risk for rabies re-emergence in Peru, jeopardizing regional dog-mediated rabies control. Additional sequence data is needed for comprehensive phylogenetic analyses.

Design of a local strategy for strengthening food sovereignty: the case of the el Pedregal municipal property of Villagarzón Putumayo.

Introduction: The article discusses the evolution of global food systems, highlighting how advances in science, technology, and international markets have led to an automated food model. This model has increased food production to combat food insecurity, but has also generated significant negative impacts on the environment, communities, and human health. The persistence of food insecurity, the deterioration of arable land and the intensive use of agrochemicals are central issues. In Colombia, and specifically in Putumayo, agriculture is crucial to the economy, but faces challenges due to globalization and dependence on agrochemicals.Methods: The study focused on the department of Putumayo, Colombia, specifically in the municipality of Villagarzón and the El Pedregal farm. Adopting a social critical approach, a non-experimental and descriptive design with a cross-sectional scope was employed, using interviews to collect qualitative data. The selection of key informants was based on criteria related to economic dependence on agriculture and recognition of agroecology as an alternative method.Results: The interviews revealed a perception of food sovereignty as an expression of independence in agricultural and livestock production. Challenges identified include the need for investment and incentives, overcoming cultural barriers and the importance of effective technical advice. Technology transfer, focusing on integrated pest management and the use of on-farm inputs, was highlighted as crucial for the transition to agroecological practices. Challenges include overcoming cultural and economic constraints and the need for committed, quality advice.Conclusions: Strengthening food sovereignty in Villagarzón, Putumayo, requires a local strategy that promotes producer independence, encourages internal production, and ensures the commitment and active participation of both producers and technicians. Complementarity, understood as collective work to obtain and govern resources and capacities, emerges as a key to the sustainable development of the agricultural community. The importance of quality technical assistance and a focus on agroecology is emphasized.

Irrigation, migration and infestation: a case study of Chagas disease vectors and bed bugs in El Pedregal, Peru.

The city of El Pedregal grew out of a desert, following an agricultural irrigation project in southern Peru. To describe infestation patterns by triatomines and bed bugs and their relationship to migration and urbanization. We conducted door-to-door entomological surveys for triatomines and bed bugs. We assessed spatial clustering of infestations and compared the year of construction of infested to un-infested households. To gain a better understanding of the context surrounding triatomine infestations, we conducted in-depth interviews with residents to explore their migration histories, including previous experiences with infestation. We inspected 5,164 households for Triatoma infestans (known locally as the Chirimacha); 21 (0.41%) were infested. These were extremely spatially clustered (Ripley's K p-value < 0.001 at various spatial scales). Infested houses were older than controls (Wilcoxon rank-sum: W = 33; p = 0.02). We conducted bed bug specific inspections in 34 households; 23 of these were infested. These were spatially dispersed across El Pedregal, and no difference was observed in construction age between bed bug infested houses and control houses (W = 6.5, p = 0.07). The establishment of agribusiness companies in a desert area demanded a permanent work force, leading to the emergence of a new city. Migrant farmers, seeking work opportunities or escaping from adverse climatic events, arrived with few resources, and constructed their houses with precarious materials. T. infestans, a Chagas disease vector, was introduced to the city and colonized houses, but its dispersal was constrained by presence of vacant houses. We discuss how changes in the socioeconomic and agricultural landscape can increase vulnerability to vector-borne illnesses.

Deciphering the sources and processes feeding young monogenetic volcanoes from the Michoacán Guanajuato Volcanic Field (Mexico): A study case of El Astillero and El Pedregal

El Astillero and El Pedregal monogenetic volcanoes formed ∼500–700 CE in the Tancítaro region in the southern part of the Michoacán-Guanajuato volcanic field, only 25 km to the SW of the historic Paricutin volcano. The ∼6-year-long eruption was characterized by a change from explosive to effusive activity, accompanied by a shift in the location of the active vents. Initial activity was Strombolian-explosive and first formed the El Astillero cone before turning effusive with the emission of several lava flows. Then, a new vent located 2 km to the ENE opened and produced the purely effusive (non-explosive) El Pedregal lava flow field. As the eruption progressed, the bulk magma composition (major and trace elements) changed from basaltic andesite to andesite (SiO2 = 52–59 wt%), which is also reflected in a successive change in the petrography of the erupted tephras and lavas. However, the El Pedregal lava sequence shows small Mg# reversals followed by a marked final reversal to more mafic compositions. Likewise, 87Sr/86Sr (0.70388–0.70403), 143Nd/144Nd (0.512836–0.512742), 206Pb/204Pb (18.632–18.671), 207Pb/204Pb (15.583–15.598), 208Pb/204Pb (38.376–38.450), 176Hf/177Hf (0.28301–0.28290), and 187Os/188Os (0.1258–0.1865) isotope ratios changed systematically as the eruption progressed, and record a final shift to a distinct isotopic signature. The spatio-temporal proximity of both vents and the petrographic and geochemical characteristics of their magmas suggest a comagmatic evolution that can be explained by a combination of variable degrees of magma recharge, magma mixing, and fractional crystallization of subduction-modified mantle melts. A similar combination of magmatic processes for the genesis and evolution of these magmas has also been proposed for other young monogenetic volcanoes in the Michoacán-Guanajuato volcanic field (e.g., Paricutin, Jorullo, and the Tacámbaro cluster). Accordingly, primitive magmas in the Trans-Mexican Volcanic Belt are subduction-modified mantle melts that evolve largely by crystal fractionation and pass through the crust without significant assimilation.

Evaluation of growth development and pigmentation of Heros severus cultured in a biofloc system with enriched pigment diets

This study aimed to evaluate the development and the increase in the skin pigmentation of the organism Heros severus cultured in a biofloc system with diets enriched with carotenoid pigments. The culture was made in 80 L water tanks with 20 juvenile organisms of H. severus; each treatment was made by duplicate. Four experimental diets were used: a) trout feed, El Pedregal®; b) TetraColor®; c) carrot and d) beetroot. The diet that obtained the highest values regarding the growth of the fish was the control diet. Regarding the coloration of the fish, the beetroot diet was the diet that presented the highest values with 9.55 μg of total carotenoids in tissue, presenting significant differences (P = 0.001) concerning the other diets, proving that a diet based on beetroot can be a good option for the culture of ornamental fish. Because it allows the organisms to have a survival rate above 90%, have similar growth to the control group, and a significant improvement in coloration, being a natural carotenoid low-cost source to improve the commercialization of organisms. Nevertheless, it did not present significant differences (P = 0.005) regarding beetroot and TetraColor® diets, while it presented significant differences with the carrot diet.

Hydrographical characteristic of basins of Bahia de Navidad, Jalisco, Mexico

A physical characterization of the drainage area of the Bahía de Navidad, Jalisco, Mexico was carried out, based on different parameters and hydrographic indices. The results allowed to identify and define more precisely the baseline of the hydrographic behavior of three small "sub" basins that drain and flow into Pacific Ocean. 1) Arroyo El Pedregal, a high-risk creek, impacts independently on San Patricio-Melaque. 2) Arroyo El Organito, a moderate risk creek, runs into El Tule lagoon, and surrounds urbanized areas. 3) Arroyo Seco, its low hazard determines the hydrological conditions of Barra de Navidad lagoon. In conclusion, environmental deterioration, high degree of ecological fragmentation and deforestation, coupled with hydrographic specificities calculated by indexes, make them highly susceptible in different degrees to situations of risk and emergency due to floods and alluvial landslides, in face of increasingly frequent and powerful hydrometeorological events in recent years.

Life cycle and description of the immature stages of a terrestrial firefly endemic to Mexico: Photinusextensus Gorham (Coleoptera, Lampyridae).

The life cycle, morphology, and bionomy of Photinusextensus Gorham, 1881, an endemic species of Mexico, are described. Redescriptions of adults (male and female) are also presented. Larvae were reared to the adult stage from eggs laid by females collected at the El Pedregal de San Ángel Ecological Reserve, south of Mexico City. The activity period of adults of P.extensus begins at the end of July and finishes by the end of August. Females lay between 3 and 198 eggs. Larvae hatch from the eggs after a period of 11 to 71 days, undergo 6 larval instars and a pupal stage in an annual cycle. Morphological characters of the sixth larval instar of P.extensus are compared with those of several other genera assigned to the tribe Photinini. Knowledge of the natural history of firefly larvae is relevant since most species do not feed as adults and therefore depend on resources acquired during the larval stage.

Watermain's failure index modeling via Monte Carlo simulation and fuzzy inference system

The aging and degradation of water supply systems are deemed serious problems that cause pipeline failure and breakages. The risk of watermains failure assessment is one of the key strategies that can pinpoint pipes at risk and maintain their sustainability. This research paper showcases a novel method for deterioration modeling in conjunction with quantifying the water network’s failure index (FI). The methodology builds on various algorithms, computational intelligence, and interactions between numerous factors. It involves developing two intelligent models; the first is the Monte Carlo Simulation Model (MCSM) that is designed to estimate the deterioration indices (DIs) of watermains through intricate iterative simulations. The produced indices are then streamlined and channeled to the fuzzy engine to develop the second model, namely, the fuzzy inference system model (FISM). After designing the model’s configuration, the DIs are mapped to 84 fuzzy-if-then-rules that are in turn mapped to output values; finally, the fuzzy consolidator generates one crisp number that represents the watermain’s FI. The developed method is implemented on the water system of the City of El Pedregal in Peru. The results indicate a moderate risk of failure status, which corresponds to 62.3 FI. Moreover, the efficacy of this method is verified against the multiple linear regression (MLR) method and proved to be sound. This research provides insights for infrastructure managers in the aspects of when to intervene, what to maintain, replace, or rehabilitate, and how to focus their constrained funding on the most deserving assets.

3D Interactive Modeling of Pipe Failure in Water Supply Systems

AbstractThe increased incidences of pipe breaks worldwide are posing a serious threat to potable water security in urban communities. The consequences may involve water loss and service interruptions, compromised water quality, infrastructure disruptions, and loss of revenue. Thus, creating failure assessment models is quite crucial to sustain water distribution networks (WDNs) and to optimize maintenance spending. This research paper aims at developing an assessment framework for water systems, as well as modeling the failure phenomena toward sustainable management of underground infrastructure. The city of El Pedregal in Peru was chosen to exemplify the methodology of the research due to the rapid pace of urbanization and growing economic activities in the region, which make water infrastructure even more critical. The framework is based on the application of modeling techniques stemming from statistical regression analysis (RA) and 3D schematic representation. First, the influential factors that lead to the deterioration of the WDNs are determined. Second, the RA technique is leveraged to evaluate and model the failure rate through consecutive simulation operations and a 3D surface plot. Finally, the efficacy of the model is investigated using different performance metrics, in conjunction with a residual analysis scheme. The validation results revealed the robustness of the model with R‐squared (R2) and the sum of squares error (SSE) of 0.9767 and 0.0008, respectively. The developed model is a predictive tool that can be used by municipal engineers as a preemptive measure against future pipeline bursts or leaks.

Toward urban sustainability and clean potable water: Prediction of water quality via artificial neural networks

Water quality failure is a long-standing problem worldwide, causing illness, poisoning, disease outbreak, and claiming human lives in the urban communities. Potable water can be compromised due to a myriad of physical, operational, and environmental factors, such as contaminants intrusion into water pipelines, leaching, disinfection byproducts , chemical or microbial permeation , and pollution. The prediction of potable water quality has seldom been researched, while a novel automated model that offers a proactive approach can be developed to promote sustainability-based strategies. This paper elaborates the impacts of the aforementioned factors on the quality of potable water using the Artificial Neural Networks (ANNs) and risk analysis techniques . The ANN model was developed based on historical data obtained from the water distribution networks (WDNs) of the City of El Pedregal, Peru. The data were streamlined and fed to the neural network to be trained. Subsequent to multiple iterations via the scaled conjugate gradient algorithm, the optimized performance was generated and passed to the trained network to forecast the water quality failure in WDNs. The model performance was tested and validated against different statistical error terms and indicators. The mean absolute error and root-mean-squared error in the ANN failure prediction were computed as 0.08 and 0.15, whereas the average validity of the network was generated to be 92%. Based on the trained neural network, the degree of influence of each factor was determined through implementing a sensitivity analysis. It was found that water quality, water pressure, and operational and maintenance practices had the maximum influence on the risk of failure in water infrastructure. Policy makers and managers can benefit from the proposed model since ANN is already trained, by predicting water quality whenever new data become available. Prediction results will indicate the level of risk (low, moderate, high) to the inhabitants, thereby preemptive measures can be taken to avoid any illness or disease outbreak. • Prediction of water quality via artificial neural network and risk analysis model. • The model assessed water contamination and pipe sustainability with 92% average validity. • Sensitivity analysis assessed the influence of model’s factors on the risk of failure. • Water quality and its related environmental factors had the highest influence rate. • Pipe diameter, and pipe thickness had the least influence rates.

Rehabilitation of a whiskered screech-owl (Megascops trichopsis) in a wildlife care center in Mexico City

A whiskered screech-owl (Megascops trichopsis), the second smallest owl of the genus Megascops in Mexico, was admitted at the Wildlife Care Center of El Pedregal de San Angel Ecological Reserve. After performing the physical examination we found no pathologies, but the owl was not able to fly or to hunt successfully. Based on these we determined that the owl was candidate for rehabilitation for the purpose of reintroducing it to the wild. During the rehabilitation, short indoor, long outdoor and vertical flights were carried out. In addition, we offered different live preys to simulate hunting behavior. After rehabilitation, we take blood and fecal samples. Also, a complete ophthalmological examination was carried out. Before the release, a general physical evaluation was carried out where the owl showed an adequate weight (120 g). We did not find endoparasites, or alterations in the ophthalmological exam. The owl was alert and elusive, with no signs of habituation to human contact. Also, a successful flight and hunting behavior was observed. Their hematological values were within the optimal ranges reported for Megascops asio and Asio flammeus. This is the first report of hematological and biochemical values of this species.

Pressure data-driven model for failure prediction of PVC pipelines

Polyvinyl chloride (PVC) pipes are used extensively in water infrastructure due to their lightweight, low cost, and ease of jointing. Failure occurrences in PVC pipes are attributed to poorly manufactured pipes, bad installation, excessive operating conditions, or third-party damage. Data-driven modeling techniques have been widely used in simulating and solving water infrastructure problems, specifically when the collected data are limited. The objective of this paper is to develop a data-driven modeling system that utilizes computational approaches and provides the analytical underpinnings to predict future PVC pipe failures. The system is based on data from El Pedregal City in Peru, simulation and regression algorithms, and supported by easy-to-perceive schematic representations. The hydraulic pressure and flow rate data are streamlined and fed to the regression machine. Subsequent to successive simulation iterations and various polynomial functions, the best fit model is selected. The efficacy of the model is investigated via different performance metrics, in tandem with a residual analysis scheme. The validation results revealed the robustness of the model with mean absolute error (MAE) of 0.35. The proposed model is a predictive tool that can be used by utility managers as a proactive measure against future pipeline bursts or leaks.

Molecular detection of Bartonella, Ehrlichia and Mycoplasma in feral dogs of El Pedregal de San Angel Ecological Reserve in Mexico City.

Free-ranging and feral dogs represent a group of unattended companion animals. They impact wild animal populations by predating native species, displacing predators and introducing exotic pathogens. The aim of this work was to describe the molecular occurrence of Rickettsia, Ehrlichia, Anaplasma, Mycoplasma and Bartonella in feral dogs. The study was carried out in the last relict of a protected area in Mexico City. Blood clots samples from 19 dogs were obtained and analyzed for detection of specific fragments of the 16S-rRNA gene for Anaplasma, Ehrlichia and Mycoplasma and citrate synthase (gltA) for Bartonella and Rickettsia. Our results showed that DNA from three bacteria species (Bartonella vinsonii subsp. berkhoffii, Ehrlichia canis and Mycoplasma haemocanis) was present with frequencies ranging from 5.3 to 15.8%. This is the first record of B. vinsonii subsp. berkhoffii and M. haemocanis in dogs from México, and also the first finding of Ehrlichia canis in Mexico City. It is important to perform surveillance of feral dog populations in order to identify the impact of these pathogens on wild animal populations and Public Health in order to establish prevention and protection programs.

The ~ AD 500–700 (Late Classic) El Astillero and El Pedregal volcanoes (Michoacán, Mexico): a new monogenetic cluster in the making?

The recent identification of Holocene volcanic clusters in small areas within the Michoacan Guanajuato Volcanic Field (MGVF) opens several questions regarding future volcanic hazard assessments in this region. Documenting vent alignments and eruption recurrence intervals within clusters will provide parameters necessary for making temporal and spatial hazard evaluations. Here, we present a possible new case of a small cluster consisting of only two monogenetic volcanoes, El Astillero and El Pedregal located in the ~ 4400-km2 Tancitaro-Nueva Italia region in the southwestern part of the MGVF, only 25 km to the south of Paricutin volcano. We determined from paleomagnetic and radiocarbon dating that El Astillero and El Pedregal most likely erupted one after the other between AD 500 and 700 (within the Late Classic period of Mesoamerican archeology). While the eruptions were likely separated by a short period of time, the exact length is difficult to ascertain. After the ~ 6 years of total estimated eruption duration of the two volcanoes, both together occupied an area of 14.7 km2 and emitted a dense rock equivalent (DRE) volume of magma of ~ 0.5 km3. Notable characteristics of the eruptions include a switch from the explosive activity exclusive of El Astillero (Strombolian) to effusive activity early after the initiation of the El Astillero eruption, a shift in the active vents, and a progressive change in the bulk magma composition from basaltic andesite to andesite throughout the duration of the eruption. This activity first formed the El Astillero scoria cone and tephra deposits followed by its lava field and ended with the emplacement of the El Pedregal viscous lavas. The discovery of pre-Hispanic pottery sherds and obsidian artifacts underneath the El Astillero tephra fallout unambiguously attests to human activities in the area before the eruption. Judging by their eruptive style, the eruptions probably had a limited impact on the small area affected and the surrounding human activities, but the hazard for this area remains since El Astillero and El Pedregal could represent the initial stages of a new cluster that is still in the making. If so, another eruption should be expected in this area again.

Caracterización hidrográfica de las cuencas de la Bahía de Navidad, Jalisco, México

Con base en diferentes parámetros e índices hidrográficos se realizó una caracterización física del área de drenaje de la Bahía de Navidad, Jalisco, México. Los resultados permitieron identificar, y definir con mayor precisión las bases del comportamiento hidrográfico de tres pequeñas subcuencas que drenan y desembocan en el océano Pacífico; 1) Arroyo El Pedregal de peligrosidad alta impacta de manera independiente sobre San Patricio-Melaque, 2) Arroyo El Organito de peligrosidad moderada desemboca en laguna El Tule, y zonas urbanizadas aledañas, 3) Arroyo Seco de baja peligrosidad determina las condiciones hidrológicas de laguna Barra de Navidad. Se concluye que el deterioro ambiental, alto grado de fragmentación ecológica y deforestación, aunados a especificidades hidrográficas calculadas por los índices, las hace altamente susceptibles en diferentes grados a situaciones de riesgo y emergencia por inundaciones, aluviones y deslaves ante eventos hidrometeorológicos cada vez más frecuentes y potentes de los últimos años.

Modern Architecture in Latin America: Art, Technology, and Utopia

Modern Architecture in Latin America: Art, Technology, and Utopia

Análisis hidrológico de largo plazo en la cuenca del río Metztitlán Hidalgo, México, y su relación con el cambio climático

Background. Climate variability and climate change are related to changes in the climate regime, with effects on the hydrological cycle. The intense rains in short periods in the basin of Metztitlan River cause the river to quickly fill its discharge vessel (Lake Metztitlan) and flood Irrigation District 08 and nearby towns. Goals. This study undertook a long-term hydrological analysis of the Metztitlan watershed to identify signs of climate change by looking at statistical means, and it defined the limits of greatest flood risk in order to understand the affected locations. We also calculated the environmental flow and the probable discharge volumes of the Metztitlan River. Methods. The historical tendency of the runoffs from 1937 to 2008 was estimated using the Regime Shift Detection software; the environmental flow and the probable discharge volumes were evaluated based on the Tennant method. Results. The analysis showed the mean annual runoff regime: Maximum extreme rainfall occurred in 1944, 1955, 1998, and 1999; and minimum rainfall occurred in 1950 and 1997. In the mean monthly runoff regime, seven and five changes were observed in the ten and five-year longitude cuts, respectively. These imply a downward trend of runoffs in the dry period, and an upward trend in the rainy period in recent years. Conclusions. We were unable to detect any signs that might have allowed us to link these changes with climate change, although we did find a certain relationship with the El Nino-Southern Oscillation phenomenon. The highest flood risk limits lie between 1246 and 1258 meters above sea level; the susceptible populations are El Pedregal de Zaragoza, San Cristobal, Tlacotepec, Tlatepexe, and Tecruz de Cozapa. The estimations of environmental flows indicate higher reserves for September and October and the release of excessive volumes throughout the year.

Middle Jurassic volcanism in a magmatic-rich passive margin linked to the Caudiel Fault Zone (Iberian Range, East of Spain): biostratigraphical dating

During the Early and Middle Jurassic, the Iberian Basin (East of Spain) recorded the transition from a generally magma-poor passive margin, which operated during the latest Triassic and most of Early Jurassic, to a magma-rich passive margin, developed from Pliensbachian to early Middle Jurassic. The mainly submarine pyroclastic volcanism, with minor lava flows, followed active NW and NE trending extensional fault zones. One of these zones of weakness, from which the volcanic deposits were expelled to the sea bottom, was the Caudiel Fault Zone. Two volcanic phases in relation to this weakness line over the Middle Jurassic times have been identified. The main phase occurred during the deposition of the El Pedregal Formation, and the other, less significant, is included between the Casinos and the El Pedregal formations. So far, the accurate age of these volcanisms, critical in the knowledge of the palaeogeographical and geodynamical evolution of the Iberian Basin, has remained uncertain. The ammonite content of the carbonate successions, with which these rocks are interbedded, allows precise biostratigraphical dating at the chronozone scale. For this purpose, 9 sections have been measured and 360 specimens of ammonites were collected and determined. The obtained data indicate that the Middle Jurassic volcanic deposits that are linked to the Caudiel Fault Zone and included into the El Pedregal Formation show a slight diachrony. They were deposited around the boundary between the Late Aalenian Concavum and the Early Bajocian Discites chronozones. However, in very restricted areas of the Caudiel Fault Zone, an older intra-Murchisonae volcanism was recorded.

Material y memoria: transformaciones en la obra de Luis Barragán

After a few early years working in the Guadalajara of his birth, Barragan seized a dream opportunity and relocated to Spain’s capital city in 1935. In Madrid he embarked on a productive and successful career, designing multi-dwelling units for private developers for 5 years. During that time, further to what he had learnt in his travels across Europe, Barragan saw in modern architecture a catalogue of precise postulates with a reproducible vocabulary. All the buildings he authored in that period indisputably drew from modernist precepts. Nonetheless, like other modern architects, including Le Corbusier himself, Barragan experienced the desolation of white abstraction, of inert and repetitive matter: precise and effective perhaps, but unable to engage with the spiritual values nesting in the deep recesses of the architect’s memory. Around 1940 Barragan decided to break with architectural practice. In so doing he redefined it beyond the stylistic limits that had been his reference until then. The source for that redefinition was the encounter with gardens as the material and object of design, along with the strong attraction exerted on the architect by that specific type of matter. The return to stone, wood or traditional rendering arose not only out of a need to evoke his own experience, but of a desire to conjure up in these materials the memory and nostalgia of other cultures. The El Pedregal gardens and adjacent Prieto House, built in 1945-1950, constituted a veritable laboratory where Barragan, deploying a materially dense architecture, spawned beauty by uniting landscape and aesthetic expression. In a word, the architect aspired to use matter to express humanity’s emotional link with nature, its ultimate haven. With his oeuvre, Barragan blurred the boundaries between technical and humanistic concerns, sensing in every element, every object, the spiritual reasons for building. As in the Capuchin Convent at Tlalpan (1952-1955) and the Gilardi House at Mexico City (19769, with that blurring matter also participates in continuity. Such continuity, converted in his architecture into spatial succession, elicits the feel of a close-knit, changing and uninterrupted sequence. The resulting sleekness is the origin of the joyful, still delight in a work that needs mouldable materials to create that effect. All that together associates memory with the experience of materials. Inherited matter contributes to the generation of timeless and universal architecture, which portrays it not portrayed as the opposite of the spirit but rather, paradoxically, as the vehicle for its expansion.

Identification of the Volatile Compounds in the roasting Venezuela Criollo cocoa beans by Gas Chromatography-Spectrometry Mass

An identification of the volatile compounds from the fermented dried and toasted (at 20 °C, 25 minutes) cocoa beans from a population of selected cocoa, were studied. The selected material “Criollo” (205 trees) was gathered from the plantation “El Pedregal” located at the south of Maracaibo Lake, Rio Frio “ Merida state, Venezuela. The volatile fraction was extracted and analyzed by gas chromatography coupled to a mass spectrometer (SPME/MS). The goal of the researching was the quantification of the content of organic volatile compounds developed by effect of the cocoa roasting. Volatile identification was performed comparing the retention indices and mass spectra obtained with those of the compounds existing as reference in the bank of the “Wiley Mass Spectral Data”. Sixty-nine volatile compounds that were grouped into 12 chemical families were identified. Aldehydes, alcohols, acids, hydrocarbons, pyrazines and diverse compounds, were the compounds prevalent in the volatile fraction of roasted cocoa. As conclusion this research permits the establishment of the identification and sensory quality of the Venezuelan creole cocoa, is of consensus that the volatile profile of the Venezuelan cocoa, which is highly appreciated by the chocolatiers of the world, has been fewer studied. It is also observed that there is an effect of post-harvest treatment (fermentation, drying) and roasted on the formation of flavor compounds in the fraction of roasted cacao. The results of these studies also show that SPME has a significant advantage over more traditional methods for analysis of volatile compounds in the cocoa beans post-harvest process: no fermented, fermented, dried and roasted.