Rafael magallanes-quintanar

Universidad Autónoma de Zacatecas "Francisco García Salinas" · Unidad Academica de Ingeniería Eléctrica

In the context of climate change, studying changes in rainfall patterns is a crucial area of research, remarkably so in arid and semi-arid regions due to the susceptibility of human activities to extreme events such as droughts. Employing predictive models to calculate drought indices can be a useful method for the effective characterization of dro...

Certain impacts of climate change could potentially be linked to alterations in rainfall patterns, including shifts in rainfall intensity or drought occurrences. Hence, predicting droughts can provide valuable assistance in mitigating the detrimental consequences associated with water scarcity, particularly in agricultural areas or densely populate...

The escalating prevalence of Type 2 Diabetes (T2D) represents a substantial burden on global healthcare systems, especially in regions such as Mexico. Existing diagnostic techniques, although effective, often require invasive procedures and labor-intensive efforts. The promise of artificial intelligence and data science for streamlining and enhanci...

The development of medical diagnostic models to support healthcare professionals has witnessed remarkable growth in recent years. Among the prevalent health conditions affecting the global population, diabetes stands out as a significant concern. In the domain of diabetes diagnosis, machine learning algorithms have been widely explored for generati...

Some of the effects of climate change may be related to a change in patterns of rainfall intensity or rainfall scarcity. So, humanity is facing environmental challenges due to an increase in the occurrence of droughts. Forecasting of droughts based on cumulative influence of rainfall could be greatly beneficial for mitigating adverse consequences o...

Some of the effects of climate change may be related to a change in patterns of rainfall intensity or scarcity. Therefore, humanity is facing environmental challenges due to an increase in the occurrence and intensity of droughts. The forecast of droughts can be of great help when trying to reduce the adverse effects that the scarcity of water brin...

Recently, the commercial breeding of Dactylopius coccus in confined environments has been developed not to depend on seasonal production and ensure the supply chain. Previous studies have shown the technical viability of their breeding of i Opuntia in a repository also called "Nopaloteca". However, considering the genetic diversity of Opuntia in ea...

The main cause of death in Mexico and the world is heart disease, and it will continue to lead the death rate in the next decade according to data from the World Health Organization (WHO) and the National Institute of Statistics and Geography (INEGI). Therefore, the objective of this work is to implement, compare and evaluate machine learning algor...

Objective: To estimate the effects of cattle grazing exclusion on soil and vegetation conditions in grasslands of Sierra de Órganos National Park (SONP), Sombrerete, Zacatecas, Mexico. Design/Methodology/Approach: Four transects with cattle grazing exclusion were strategically established in SONP grasslands. In each transect the basal, crown and or...

Dactylopius coccus es un insecto de importancia comercial como fuente de un colorante natural denominado ácido carmínico. Para su producción comercial en cautiverio, se ha promovido la cría en cladodios suspendidos a diferentes alturas, en un sistema denominado “nopaloteca”. Sin embargo, se desconoce si su calidad y rendimiento es uniforme en los d...

Children activity recognition (CAR) is a subject for which numerous works have been developed in recent years, most of them focused on monitoring and safety. Commonly, these works use as data source different types of sensors that can interfere with the natural behavior of children, since these sensors are embedded in their clothes. This article pr...

Los efectos de la Oscilación del Sur El Niño pueden ser medidos como sus impactos sobre los rendimientos de los cultivos. Sin embargo, esos efectos sobre los cultivos principales en México han sido estudiados escasamente. En este trabajo, el objetivo principal fue identificar las correlaciones entre las anomalías de rendimiento medio anual desde 19...

A better understanding of the local and regional spatio-temporal variability of past precipitation is needed to contextualize climate change research. Monthly precipitation data from 59 stations in the state of Zacatecas, Mexico were transformed into standardized monthly precipitation anomalies for the period 1976-2010 (34 years). Cluster analysis...

Estimation of indoor location represents an interesting research topic since it is a main contextual variable for location bases services (LBS), eHealth applications and commercial systems, among others. For instance, hospitals require location data of their employees, as well as the location of their patients to offer services based on these locat...

Major Depression Disease has been increasing in the last few years, affecting around 7 percent of the world population, but nowadays techniques to diagnose it are outdated and inefficient. Motor activity data in the last decade is presented as a better way to diagnose, treat and monitor patients suffering from this illness, this is achieved through...

In the area of recognition and classification of children activities, numerous works have been proposed that make use of different data sources. In most of them, sensors embedded in children’s garments are used. In this work, the use of environmental sound data is proposed to generate a recognition and classification of children activities model th...

Tomato plants are highly affected by diverse diseases. A timely and accurate diagnosis plays an important role to prevent the quality of crops. Recently, deep learning (DL), specifically convolutional neural networks (CNNs), have achieved extraordinary results in many applications, including the classification of plant diseases. This work focused o...

As the earth atmosphere warms, it is unclear how the precipitation will change or how these changes will impact regional rainfall. For the study of spatial and temporal variability of rainfall, several indexes have been developed. The Standardized Precipitation Index (SPI) that only involves recorded rainfall data has been used as a tool for climat...

Depression is a mental disorder which typically includes recurrent sadness and loss of interest in the enjoyment of the positive aspects of life, and in severe cases fatigue, causing inability to perform daily activities, leading to a progressive loss of quality of life. Monitoring depression (unipolar and bipolar patients) stats relays on traditio...

Depression is a mental disorder characterized by recurrent sadness and loss of interest in the enjoyment of the positive aspects of life, in addition to fatigue, causing inability to perform daily activities, which leads to a loss of quality of life. To monitor depression (unipolar and bipolar patients), traditional methods rely on reports from pat...

Oral health represents an essential component in the quality of life of people, being a determinant factor in general health since it may affect the risk of suffering other conditions, such as chronic diseases. Oral diseases have become one of the main public health problems, where dental caries is the condition that most affects oral health worldw...

Knee pain is the most common and disabling symptom in Osteoarthritis (OA). Joint pain is a late manifestation of the OA. In earlier stages of the disease changes in joint structures are shown. Also, formation of bony osteophytes, cartilage degradation, and joint space reduction which are some of the most common, among others. The main goal of this...

The indoor location of individuals is a key contextual variable for commercial and assisted location-based services and applications. Commercial centers and medical buildings (e.g., hospitals) require location information of their users/patients to offer the services that are needed at the correct moment. Several approaches have been proposed to ta...

Opuntia genus is distributed around the world. It grows in a wide range of environmentalconditions, which imply a great variability in fruit yield. Productivity also varies at within-treelevels due to limiting factors like fruiting cladode size. Such a variation can be reducedthrough horticultural practices. However, there are little evidences on t...

Se analizaron series de largo plazo de evaporación en 35 estaciones localizadas en el estado de Zacatecas, México, con el objetivo de identificar sus tendencias. Adicionalmente, se analizaron los espectros de potencia de las anomalías de evaporación con el fin de identificar sus frecuencias y su posible conexión con fenómenos periódicos. Los result...

This work presents a human activity recognition (HAR) model based on audio features. The use of sound as an information source for HAR models represents a challenge because sound wave analyses generate very large amounts of data. However, feature selection techniques may reduce the amount of data required to represent an audio signal sample. Some o...

Advances on climate change research, as well as the assessment of the potential impacts of climate change on water resources, would allow the understanding of the spatial and temporal variability of land-surface precipitation and evaporation time series at local and regional levels. In the present study, the spectral analysis approach was applied o...

A new method to measure the polarization resistance on electrochemical cells is proposed. The method is based on the application of a new pulsed excitation, which exhibits low pass frequency contents, and time domain analysis. In other pulsed excitation methods, curve fitting algorithms are used to find values for equivalent RC models. In our appro...

Opuntia ficus-indica (L.) Miller species grows in a wide range of environmental conditions, which implies a great variability in fruit yield and fruit ripening, among other aspects. Therefore, the aim of this research work was to identify the dependences of fruit yield per cladode on fruiting cladode fresh or dry matter, on fruiting cladode length...

In Opuntia ficus-indica (L.) Miller, the wide range of environmental conditions in which it grows implies a great variability in fruit yield and fruit ripening, among other issues. In this research work, we studied the dependence of fruit weight or number of fruits per cladode on fruiting cladode fresh or dry weight for the 'Rojo Pelon' variety by...

Compositional Nutrient Diagnosis technique involves a yield target for discriminating between high- and low-yield subpopulations when developing norms. Traditionally, this yield value is estimated by finding the inflection point of the cumulative variance ratio function versus yield relationship through a third-order equation. However, yield target...

The aim of this paper was to estimate the trends in time series of maximum and minimum temperatures, recorded at 24 weather stations of Zacatecas State, to analyze them with the simple linear regression technique. Out o0f the 24 series of maximum temperatures, 13 showed a significant trend (p< 0.05), six showed negative a trend and seven showed a p...

Opuntia ficus-indica (L.) Mill. is growing in 25 countries to harvest its fruit (cactus pear), young cladodes (stems or 'nopalitos') and mature cladodes. Mexico is the only country with commercial production of 'nopalitos' of O. ficus-indica (L.) Mill. covering 12,041 ha with annual mean yields, at farm level, ranging from 9.03-99.93 t ha -1, and a...

Optimum concentrations and/or sufficiency ranges of nutrients are useful for a correct diagnosis and improvement of nutrient status of cultivated plants. To develop boundary-line approach (BLA) standards for Opuntia ficus-indica L., a database of N, P, K, Ca, and Mg concentrations in 1-year-old cladodes and cladodes fresh-matter yield was used. The...

It is a need to know optimum concentrations and/or optimum ranges of nutrients useful for correct diagnosis and improvements of nutrient status of cultivated plants. Recognizing the need to develop correct nutritional standards, it is convenient to improve or to ensure the reliability of those already determined. Having in mind that aim, boundary–l...

It is a need to know optimum concentrations and/or optimum ranges of nutrients useful for correct diagnosis and improvements of nutrient status of cultivated plants. Recognizing the need to develop correct nutritional standards, it is convenient to improve or to ensure the reliability of those already determined. Having in mind that aim, boundary-l...

In crop science, tools of non-linear dynamics, fractals, chaos, intermittency and self-organized criticality may be employed and applied to the analysis of spatial variability and temporal behavior of agro-meteorological variables, soil properties, plant attributes, commercial yields, and prices of the agricultural products in order to gain knowled...

The Capsicum genus is one of the most useful plants taxonomic groups throughout the world. Although the species C. annuum includes the largest amount of cultivated pepper types and varieties, there are cultivars from other species under domestication process. The caribe or chiltepin cultivar of C. frutescens is currently under this process due to i...

There are few reports on the interactive effects of nutrients in Opuntia ficus-indica. The recognition of the importance of nutrient balance in crop production is an indirect reflection of the contribution of nutrient interactions to yield. A field experiment to identify nutrient interactions in cladodes of O. ficus-indica plants cultivated with th...

Preliminary compositional nutrient diagnosis (CND) norms for maize (Zea mays L.) were developed from a small database as means and standard deviations of row-centered log ratios VX of five nutrients [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)] and a filling value R, which comprised all nutrients not chemically ana...

A greenhouse experiment using 24 plastic pots filled with 6 kg of Pb- and Cd-contaminated soil was carried out. In all 24 pots, soils were heavy metal-contaminated with 10 mg Cd kg -1 soil and 500 mg of Pb kg -1 soil by using CdCl and PbNO 3. Two-month-old tobacco (Nicotiana tabacum L.) plants were used to extract these heavy metals. Results showed...

This study calculated the compositional nutrient diagnosis (CND) norms of cowpea (Vigna unguiculata (L.) Walp.), as well as identified significant nutrient interactions of this crop growing in an irrigated calcareous desert soil. Three genotypes were distributed in rows in a 2-ha field. The soil showed high heterogeneity in its chemical properties....

The appraisal of soil fertility and the assessment of plant mineral requirements are fundamental for crop management. This study was conducted to determine nutrient norms and to identify significant nutrient interactions in nopal (Opuntia ficus-indica). Preliminary compositional nutrient diagnosis (CND) norms were developed from a small database as...

Mineral-nutrient stress is one of the main factors limiting crop production, especially in arid lands. The mineral requirement of a crop is difficult to determine, and the interpretation of foliar chemistry composition is not easy. This study was conducted to compute the minimum yield target for fresh fruit of yellow pepper (Capsicum annuum L.) and...

The appraisal of soil fertility and the assessment of plant mineral requirements are fundamental for crop management. This study was conducted to determine nutrient norms and to identify significant nutrient interactions in nopal (Opuntia ficus-indica). Preliminary compositional nutrient diagnosis (CND) norms were developed from a small database as...