Population dynamics of Stenoma catenifer Walsingham (Lepidoptera: Depressariidae) on Hass avocado orchards in México

del Carmen Velázquez-Martínez Guadalupe,González-Hernández Héctor,Equihua-Martínez Armando,Refugio Lomeli-Flores J.,Rojas Julio C.,Lopez-Collado Jose 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.1

Avocado production in Mexico represents an income of more than $3.2 billion dollars per year in foreign ex change. Unfortunately, several factors can limit the export of this fruit. One of such limiting factor is the avocado seed moth, Stenoma catenifer; however, its population dynamics is barely known. Therefore, is relevant to study the environmental factors affecting population changes, aimed to improve its management. In this study, we monitored the population fluctuations of S. catenifer males and explored its relationship with temperature and relative humidity by using pheromone-baited traps in Hass avocado orchards in the state of Colima, Mexico. From June 2018 to June 2019, a total of 6,836 males of the avocado seed moth were collected, with two population peaks. The first in June-August, during the fruiting stage, and the second in December-January, coinciding with the end of fruiting and flowering stages. Fruit infestation ranged from 0.0 to 65.0% in the or chards examined. Cluster analysis and principal coordinate analysis indicated that sampling time and relative humidity group together but differ from temperature. The effect of relative humidity and temperature on catches was analyzed by relating non-parametric bivariate distributions. The highest male catches were recorded at temperatures greater than 15.8 ◦ C and relative humidity greater than 60% while low relative humidity did not favor moth catches. These results may be useful to predict bioecological conditions for the occurrence of pop ulations of this pest.

Numerical analysis of a hydraulic gear micro motor

Alberto Flores-Márquez,Fernando Velázquez-Villegas,Gabriel Ascanio 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.5

This study investigates the critical parameters that have the most impact on the structural capacity of hydraulic gear micro motors,namely, motor configuration, output torque, and speed. Seven different motor configurations were evaluated in terms of output speed and torque, which depend on the number and size of gears. During motor operation, reactive loads generated by drag forces, viscous damping forces, and oil pocketing within two adjacent teeth in contact were numerically calculated. Stress analysis using the finite element method was also performed to evaluate the structure of the aforementioned gear motor configurations. The results demonstrated that the structural capacity of a hydraulic motor does not necessarily increase when using larger gears or by increasing the number of gears. Reactive loads increase as rotational speed and gear size increase. Higher lubricant pressure is also required to attain the required output torque and velocity.

Expression of heat shock protein genes in Simmental cattle exposed to heat stress

Guzmán Luis Felipe,Martínez-Velázquez Guillermo,Villaseñor-González Fernando,Vega-Murillo Vicente Eliezer,Palacios-Fránquez José Antonio,Ríos-Utrera Ángel,Montaño-Bermúdez Moisés 아세아·태평양축산학회 2023 Animal Bioscience Vol.36 No.5

Objective: In tropical, subtropical and arid zones, heat stress is the main cause of productivity reduction in cattle. When climate stressors occur, animals become thermal adapted through differential expression of some genes, including heat shock proteins (HSP) family. The aim of this study was to determine levels of expression of HSP60, HSP70, and HSP90 genes in Simmental cattle raised in tropical environments of Mexico. Methods: In this study, expression of HSP60, HSP70, and HSP90 genes was analyzed in 116 Simmental cattle from three farms with tropical climate located in western Mexico. Animals were sampled twice a day, in the morning and noon. Gene expression was evaluated by quantitative polymerase chain reaction using probes marked with fluorescence. The MIXED procedure of SAS with repeated measures was used for all statistical analysis. Results: HSP60 gene expression differences were found for sex (p = 0.0349). HSP70 gene differences were detected for sampling hour (p = 0.0042), farm (p<0.0001), sex (p = 0.0476), and the interaction sampling hour×farm (p = 0.0002). Gene expression differences for HSP90 were observed for farm (p<0.0001) and year (p = 0.0521). HSP70 gene showed to be a better marker of heat stress than HSP60 and HSP90 genes. Conclusion: Expression of HSP70 gene in Simmental herds of the tropical region of western México was different during early morning and noon, but the expression of the HSP60 and HSP90 genes was similar. Identification of resilient animals to heat stress will be useful in the genetic improvement of the Simmental breed.

Analysis of productivity, efficiency, and their explanatory factors in the fast fashion sector: New evidence from the international environment

Moreno Justo de Jorge,Velázquez Francisco Javier Martínez 한국마케팅과학회 2023 Journal of Global Fashion Marketing Vol.14 No.4

This paper analyses the performance levels of the leading compa- nies in the fast fashion sector, Inditex, H&M and Gap in the period 2005–2019. Additionally, the isolated analysis of Inditex, as a case study, has been considered, with special emphasis on its interna- tionalization process, in the period 1995–2019. The use of different approaches to obtain efficiency and productivity (DEA, intertem- poral and Windows models), have enriched this work. The results obtained indicate a good performance in the resource manage- ment of the companies analyzed. In the case of Inditex, a curvilinear U-shaped relationship was found between efficiency and its level of internationalization. In addition, average increases in TFP are observed in the case of Gap and Inditex. However, Inditex shows a trend of continuous improvement in most of the sub-periods considered, reaching an improvement of 18%.

Numerical simulation and design of a parabolic trough solar collector used as a direct generator in a solar-GAX cooling cycle

Daniel Sauceda,Nicolás Velázquez,Octavio García-Valladares,Ricardo Beltrán 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.6

In this work, a solar parabolic trough collector (PTC) has been dimensioned and its technical feasibility has been evaluated in order to be used as ammonia direct vapor generator in an advanced absorption air-cooled Solar-GAX cycle of 10.6 kW cooling capacity. A detailed numerical simulation model that takes into account the geometry and the optical, thermal and fluid dynamic behavior of the PTC has been developed. The model has been solved in order to reach minimal thermal losses through the PTC, and maximum coefficient of performance (COP) of the Solar-GAX cycle. Under design conditions, the solar PTC efficiency, the COP of the Solar-GAX cycle and the global efficiency of the system were 0.62, 0.87 y and 0.54 respectively. The calculated efficiency is 25.5 % higher than that provided by a single effect water-lithium bromide cycle coupled in an indirect form with a solar PTC system.

Antimicrobial Activity of Northwestern Mexican Plants Against Helicobacter pylori

Ramón E. Robles-Zepeda,Carlos A. Velázquez-Contreras,Adriana Garibay-Escobar,Juan C. Gálvez-Ruiz,Eduardo Ruiz-Bustos 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.10

Helicobacter pylori is the major etiologic agent of such gastric disorders as chronic active gastritis and gastric carcinoma. Over the past few years, the appearance of antibiotic-resistant bacteria has led to the development of better treatments, such as the use of natural products. This study evaluated the anti–H. pylori activity of 17 Mexican plants used mainly in the northwestern part of Mexico (Sonora) for the empirical treatment of gastrointestinal disorders. The anti–H. pylori activity of methanolic extracts of the plants was determined by using the broth microdilution method. The 50% minimum inhibitory concentrations ranged from less than 200 to 400 μg/mL for Castella tortuosa, Amphipterygium adstringens, Ibervillea sonorae, Pscalium decompositum, Krameria erecta, Selaginella lepidophylla, Pimpinella anisum, Marrubium vulgare, Ambrosia confertiflora, and Couterea latiflora and were greater than 800 μg/mL for Byophyllum pinnatum, Tecoma stans linnaeus, Kohleria deppena, Jatropha cuneata, Chenopodium ambrosoides, and Taxodium macronatum. Only Equisetum gigantum showed no activity against H. pylori. This study suggests the important role that these plants may have in the treatment of gastrointestinal disorders caused by H. pylori. The findings set the groundwork for further characterization and elucidation of the active compounds responsible for such activity.

Development of Chemometric Models Using Infrared Spectroscopy (MID-FTIR) for Detection of Sulfathiazole and Oxytetracycline Residues in Honey

Karina Uribe Hernández,Tzayhrí Gallardo Velázquez,Guillermo Osorio Revilla,Norma Almaraz Abarca,Maylet Hernández Martínez 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.4

Chemometric models using mid-infrared (MID-FTIR) spectroscopy were developed for detection and quantification of oxytetracycline and sulfathiazole contamination in honey samples. Low standard error of calibration (SEC) and prediction (SEP) values were achieved using a partial least squares algorithm (SEC= 1.02 and SEP=1.39 for oxytetracycline and SEC=1.24 and SEP=1.79 for sulfathiazole). Chemometric model-predicted concentrations of antibiotics were compared with ELISA results with coefficient of determination R2=0.8577 for oxytetracycline and R2=0.8216 for sulfathiazole. Classification of antibiotic contaminated honey samples and uncontaminated samples was carried out using Soft Independent Modeling Class Analogy analysis with a 100% correct classification rate with interclass distances in the range of 6.93-13.3. MID-FTIR chemometric models developed for detection and quantification of oxitetracycline and sulfathiazole in honey samples have been demonstrated.

Genetic variation of Colletotrichum magnum isolated from Carica papaya as revealed by DNA fingerprinting

Daisy Pérez-Brito,Alberto Cortes-Velázquez,Teresita Valencia-Yah,Anuar Magaña-Álvarez,Cuauhtémoc Navarro,Blanca Moreno,Steven Quiroga,Raúl Tapia-Tussell 한국미생물학회 2018 The journal of microbiology Vol.56 No.11

Mexico is one of the five largest producers of papaya worldwide, but losses caused by pathogens, mainly fungus, at the pre- and post-harvest stages are often more than 50% of the crop. Papaya anthracnose, caused by three different species of the Colletotrichum genus in Mexico, occupies a preponderant place in this problem. Although two of these species, C. gloeosporiodes and C. truncatum, have been characterized morphologically and genotypically, this has not occurred with C. magnum, the third species involved, about which there is very little information. Because of this, it is vital to know its genetic characterization, much more so considering that the studies carried out on the other two species reveal a wide genetic diversity, differences in pathogenicity and in the response to fungicides of the different strains characterized. In this work, Colletotrichum spp. isolates were collected at different papaya orchards in the south-southeast of Mexico. C. magnum isolates identified by species-specific primers were characterized by morphological and molecular approaches. Differences in colony characteristics resulted in five morphological groups. AP-PCR, DAMD and ISSR markers were found to be very efficient for revealing the interspecific variability of this species. The high genetic variability found in the accessions of C. magnum was linked to the geographical area where they were collected. Isolates from Chiapas State were the most variable, showing point mutations in the ITS1- ITS2 region. These results will enable a better phytosanitary management of anthracnose in papaya in this region of Mexico.

Embedded Haptic Device Implementation for Soft Tissue Rendering

Humiko Yahaira Hernández Acosta,Alejandro Miranda Cid,Alejandro Tonatiu Velázquez Sánchez,Mario Ramírez-Neria,Guillermo Manuel Urriolagoitia Calderón 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.10

In this work, a haptic robotic device and its real-time virtual reality interface, deployed in an embedded computational platform is developed, in order to simulate soft tissue rendering contact forces and effects. A control scheme based on a bilateral tele-operation system is proposed recreating a multimodal interaction between the surgical trainer (operator) and the virtual robot (slave) in force-visual feedback environment. The virtual interaction object was modeled as a restriction in the haptic engine, it was implemented with an orthogonal decomposition of contact forces algorithm, generating two independent dynamics and recreated exponential deformation forces, like ones present during the manipulation of real organic tissue. The proposed model contains the biomechanical properties of a soft tissue (pork liver), characterized in an experimental compression test with an indenter.

Response transformation factors for deterministic-based and reliability-based seismic design

Edén Bojórquez,Juan Bojórquez,Sonia E. Ruiz,Alfredo Reyes-Salazar,Juan Velázquez-Dimas 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.46 No.6

One of the main requirements of the seismic design codes must be its easy application by structural engineers. The use of practically-applicable models or simplified models as single-degree-offreedom (SDOF) systems is a good alternative to achieve this condition. In this study, deterministic and probabilistic response transformation factors are obtained to evaluate the response in terms of maximum ductility and maximum interstory drifts of multi-degree-of-freedom (MDOF) systems based on the response of equivalent SDOF systems. For this aim, five steel frames designed with the Mexican City Building Code (MCBC) as well as their corresponding equivalent SDOF systems (which represent the characteristics of the frames) are analyzed. Both structural systems are subjected to ground motions records. For the MDOF and the simplified systems, incremental dynamic analyses IDAs are developed in first place, then, structural demand hazard curves are obtained. The ratio between the IDAs curves corresponding to the MDOF systems and the curves corresponding to the simplified models are used to obtain deterministic response transformation factors. On the other hand, demand hazard curves are used to calculate probabilistic response transformation factors. It was found that both approaches give place to similar results.