Authors:Viviana Wittmann Vega, Gabriela Davidovich-Young, Eric Wong-González, Manuel Montero Barrantes Pages: e4831 - e4831 Abstract: Introduction: Consumption of fresh tomatoes has increased over the years and production systems (conventional or hydroponic), harvest and post-harvest practices, irrigation water and harvest containers, can affect the microbiological quality of the final product. Objective: To compare the microbiological quality of the cultivated or harvested fruit, the irrigation water, and the harvest containers in two tomato production farms (conventional and hydroponic). Methods: We carried out three sampling visits in each farm (repetitions), taking, in each repetition, 3 tomatoes of each type (composite sample), 50 ml of irrigation water and swabbing 50cm2 of the surface of three harvest containers (composite sample). We determined indicator microorganisms such as total aerobic mesophilic count, mold and yeast count, total coliforms, thermotolerant coliforms and E. coli. Presence of Listeria monocytogenes was also analyzed in fruits. We applied student's t-tests at a significance level of 5%. Results: Total aerobic mesophilic and mold and yeast counts of hydroponic tomato were significantly lower than in conventional tomato, while no difference in total coliform counts and E. coli was detected. L. monocytogenes was absent in all samples. The total aerobic mesophilic count was higher in the harvest containers of the conventional farm. In both farms, irrigation water was not considered a source of contamination since it had very low levels of total coliforms, thermotolerant coliforms, and E. coli. Finally, an adequate control during harvesting was presumed, having found no difference in the microbiological indicators between the cultivated and harvested tomato. Conclusion: Hydroponic tomatoes are more likely to have a better microbiological profile and longer shelf life compared to conventionally grown tomatoes, evidencing the importance of environmental control and cleaning and disinfection of all elements used in the farming, harvesting and postharvest processes. PubDate: 2023-10-28 DOI: 10.22458/urj.v15i2.4831 Issue No:Vol. 15, No. 2 (2023)
Authors:Eduardo José Artavia Durán, Oscar Mario Cubero Vázquez, Evelyn Solano Brenes, Marilyn Rodríguez Árias Pages: e4787 - e4787 Abstract: Introduction: The range of the the Honduran fruit bat, Artibeus inopinatus, extends in the south to Nicaragua and there were no previous records of its presence in Guanacaste, Costa Rica, which is the southern limit of the tropical dry forest in Central America. Objective: To record the presence of A. inopinatus in Costa Rica. Methods: In May 2023, we did a mist netting session in Playa Naranjo, Santa Rosa. Results: We captured a pregnant female. Conclusion: Our finding extends the southern distribution of A. inopinatus into northwest Costa Rica. PubDate: 2023-10-28 DOI: 10.22458/urj.v15i2.4787 Issue No:Vol. 15, No. 2 (2023)
Authors:Iván Jácome-Negrete, Adelmo Mamallacta, Daryl Andrade, Fidel Rodriguez Pages: e4780 - e4780 Abstract: Introduction: The diversity of fish species in the Amazonian foothills of Ecuador includes moderate-sized species adapted to living in fast flowing, well-oxygenated, stony-bed rivers. These species are still important for subsistence fishing. However, current studies of the ethnoichthyology of indigenous communities settled in the upper watersheds of the main Amazonian tributaries of Ecuador are still incipient. Objective: To characterize the ichthyological richness and the family fishing system of the Kichwa CEPLOA community, in the upper Ecuadorian Amazon. Methods: In 2020 we did a fish an inventory of in the Oglán river, mainly with cast net, and interviewed 18 community members about the family fishing system. Results: We recorded seventeen fish species, with a predominance of Characidae, Loricariidae and Cichlidae, all of them characteristic of well-conserved Amazonian foothill rivers. Local fishermen practice subsistence fishing with cast nets and hooks (mean 1,5kg of fish per catch). The anglers perceive a reduction in the diversity and abundance of fish fauna as well as in their sizes compared to the last decade, possible from the increase in fishing operations and the use of unsustainable catching techniques. Conclusion: The local 17 fish species are typical of well-preserved Amazonian foothill rivers. Local subsistence fishermen reported reduced diversity, abundance, and size of fish, attributed to increased fishing activities and unsustainable catching methods. Internal regulation may reduce the problem. PubDate: 2023-10-22 DOI: 10.22458/urj.v15i2.4780 Issue No:Vol. 15, No. 2 (2023)
Authors:Sally P. Horn, Erik N. Johanson, Mauricio Murillo Herrera, Kurt A. Haberyan, Taber Friedel, Chad S. Lane Pages: e4835 - e4835 Abstract: Introducción : Costa Rica tiene cientos de lagos, muchos de los cuales nunca han sido estudiados científicamente. Objetivo: Conocer limnológia de la Laguna Pozo Verde en el Parque Nacional Juan Castro Blanco, Costa Rica (~1935 m de elevación), para proporcionar datos de referencia para estudiar cambios futuros. Métodos: Medimos la profundidad y temperatura del agua y la profundidad de Secchi; sedimentos superficiales analizados; y examinó mapas e imágenes de satélite. Resultados: Aunque algunos la describen como formada por procesos volcánicos, la Laguna Pozo Verde probablemente se formó en un deslizamiento de tierra, que ocurre con frecuencia en esta zona lluviosa en la empinada ladera sur del inactivo volcán Porvenir. Nuestros sondeos mostraron una profundidad máxima de 9,25 m cerca del centro del lago. El agua era moderadamente transparente (profundidad de Secchi 2,6 m), con pH circunneutro y temperaturas de 15,9 a 18,1 °C, con estratificación débil a 0,5 m. Los sedimentos superficiales contenían 27% de materia orgánica y tenían relaciones C/N y valores de isótopos de carbono estables consistentes con algas lacustres y plantas C 3 ; Surirella angusta compuso más del 90% de las diatomeas. Conclusión: La laguna es significativamente más omera de lo informado y los sedimentos superficiales albergar una combinación de diatomeas única entre los 88 lagos examinados en Costa Rica. PubDate: 2023-10-21 DOI: 10.22458/urj.v15i2.4835 Issue No:Vol. 15, No. 2 (2023)
Authors:Walter Vargas-Segura, Anthony Cordero Ramírez, Alexander Mora-Fallas Pages: e4709 - e4709 Abstract: Introduction: The precision in determination of the dose using radiochromic films as a dosimeter is influenced by three main aspects: the dose delivery capacity of the radiation unit, the response of the film when exposed to radiation, and the capacity of the scanner to digitize the films and transform them into intensity values. This work focuses on the last aspect. Objective: To establish a methodology for the evaluation of the variability of the dose due to the repeatability of scans and the position of the film in the scanning area, under calibration conditions of radiochromic films for three different resolutions. Methods: Pieces of EBT3 radiochromic films were irradiated at 11 different dose values, which were scanned at 3 different resolutions, creating a calibration curve for each resolution. These curves are used to determine dose variations due to film position in the scan area and scan repeatability; for this purpose, we measured 5 dose values per film, for each of 9 images by resolution, with a total of 27 images. Results: In the three resolutions studied, uncertainties below 1% were found due to variation in the position of the film in the scanning area and uncertainty below 2% in the case of scan repeatability. Conclusions: The values obtained from the sources of uncertainty studied were not negligible; therefore, they must be included in the total uncertainty budget of the radiochromic film dose measurement process. Working with dose values eliminates the dependence on the resolution. PubDate: 2023-10-18 DOI: 10.22458/urj.v15i2.4709 Issue No:Vol. 15, No. 2 (2023)
Authors:Stephanny Sánchez-Vargas, Paula Vargas-Jiménez, Luis Vega-Corrales, Junior Pastor Pérez-Molina Pages: e4675 - e4675 Abstract: Introduction: The spread of antimicrobial resistance in natural environments continues to be reported throughout the world; nevertheless, there is no study about phytotelms (water in the natural cavities of plants) in the deep understory of tropical cloud forests from Costa Rica. Objective: To detect phytotelm antibiotic-resistant bacterial strains in a Costa Rican forest and nearby town. Methods: We used the disk diffusion method to analyze the antimicrobial resistance of 10 gram-negative bacterial strains from phytotelm water collected from 10 bromeliads and 10 heliconias in both sites. Results: Three strains were multidrug resistant to more than three antibiotics in each site, and only one strain was susceptible to all antibiotics. Antibiotic resistance was similar in both environments. Conclusions: Phytotelm can be a rapid, cost-effective, and simple source for detecting antimicrobial resistance in unexplored environments. PubDate: 2023-10-18 DOI: 10.22458/urj.v15i2.4675 Issue No:Vol. 15, No. 2 (2023)
Authors:Jairo Vargas Mesén, Karina Rodríguez Mora, Eddy Jirón García, Cesar Bernal Samaniego Pages: e4593 - e4593 Abstract: Introduction: Nanocellulose, the nanometer form of cellulose, can be produced through various methods, including chemical treatments, physical rupture, or their combination. Agro-industrial waste, like palm oil rachis and pineapple leaves, is commonly used as fuel or composting in plantations. However, it is not typically used for value-added products. Objective: To produce cellulose nanofibers starting with low-energy and low-input systems. Methods: We chemically characterized pineapple leaves and African palm oil rachis and subjected them to chemical degradation and mechanical treatments, to obtain cellulose nanofibers. The fibers were subsequently degraded with acetic acid (HOAc) and characterized using visible microscopy, fluorescence microscopy, infrared spectroscopy, X-ray diffraction, and transmission electron microscopy. Results: Pineapple leaves and African palm oil rachis had cellulose contents of 35,8 ± 0,5% and 17,9 ± 0,1%, respectively. We obtained nanofibers with thicknesses of 40nm and 10,8nm. Conclusion: The hybrid method of chemical treatment and mechanical rupture proved successful in obtaining fibrillar nanocellulose with low-concentration reagents. PubDate: 2023-09-18 DOI: 10.22458/urj.v15i2.4593 Issue No:Vol. 15, No. 2 (2023)
Authors:José R. Montiel-Mora, Eddy Gómez-Ramirez Pages: e4763 - e4763 Abstract: Introduction: Socioeconomic growth has caused pressure on marine ecosystems, and there is little information that can be used for the management of beaches in Nicoya, Costa Rica. Objective: To determine the physicochemical and microbiological quality of marine-coastal water in Nicoya, Costa Rica. Methods: In October 2021, and May and June 2022, we used standard methods to assess physicochemical and microbiological water conditions, in three beaches with different administrations and number of tourists. Results: Water temperature ranged between 26,1°C to 31,2°C, salinity between 22 to 31ups, dissolved oxygen from 3,6 to 7,3mg/L, and total suspended hydrocarbon values were below the detection limit. Higher fecal contamination was found in the rainy season, with maximum values of 3,5x103 NMP/100mL fecal coliforms, 1,1x103 NMP/100mL Escherichia coli and 2,4x103 NMP/100mL Enteroccocus faecalis. Conclusion: While fecal contamination was high during the rainy season, physicochemical parameters were acceptable in the three beaches. PubDate: 2023-08-29 DOI: 10.22458/urj.v15i2.4763 Issue No:Vol. 15, No. 2 (2023)
Authors:Patricia Oreamuno-Fonseca, José Eladio Monge-Pérez, Michelle Loría-Coto Pages: e4690 - e4690 Abstract: Introduction: The rescue of common bean landraces is of importance to preserve biodiversity, and to make use of this genetic base in plant breeding programs. There are few studies about this subject in Costa Rica. Objective: To characterize seeds of some common native beans in Guanacaste, Costa Rica. Methods: From April to August 2013, we collected seed samples of common bean (Phaseolus vulgaris) landraces (also called creole common beans) in Nicoya and Hojancha, through visits to local growers. We worked with Mantequilla, Nica, Revuelto, Sesenteno, Turrialba, and Vaina Blanca. Results: We found differences among varieties for quantitative variables, and a range of variation for weight of 100 seeds (17,16-26,52g), and for seed length (9,78-10,97mm), width (5,69-6,25mm), thickness (3,96-4,81mm), length/width ratio (1,69-1,84), length/thickness ratio (2,29-2,76), and width/thickness ratio (1,25-1,55). Conclusion: In Nicoya and Hojancha, there are significant variations among and within native bean seed landraces. PubDate: 2023-08-04 DOI: 10.22458/urj.v15i2.4690 Issue No:Vol. 15, No. 2 (2023)
Authors:Abiodun Obembe Pages: e4689 - e4689 Abstract: Introduction: Studies on malaria vector surveillance are useful for evidence-based control in specific communities. Such studies are lacking in Malete, a rapidly growing peri-urban community in Nigeria. Objective: To assess sibling species identity, human blood indices, and Plasmodium falciparum transmission risks by Anopheles mosquitoes, in Malete. Methods: I collected endophilic mosquitoes quarterly from inhabited houses using the pyrethrum spray catch technique. I identified the mosquitoes, and probed for the presence of human blood and P. falciparum, using standard PCR and ELISA methods, respectively. Results: Anopheles mosquitoes (90%) were the most abundant compared to Culex (10%) and Mansonia (0,5%). Specifically, A. gambiae (85%) were predominant over A. coluzzii (11%) and A. arabiensis (3%). The Anopheles sibling species had generally high human blood indices (≥0,82). However, A. gambiae man-biting rates (0,92-3,64) were higher than A. coluzzii (0-0,84) and A. arabiensis (0-0,27). Plasmodium falciparum sporozoite infection (3%) was found only in A. gambiae. Conclusion: While P. falciparum infection was 3%, long-lasting insecticidal nets should be deployed for control in Malete, particularly of A. gambiae. PubDate: 2023-07-31 DOI: 10.22458/urj.v15i2.4689 Issue No:Vol. 15, No. 2 (2023)
Authors:Juan Diego Cordero-Castro, Rodolfo WingChing-Jones Pages: e4578 - e4578 Abstract: Introduction: The cattle industry in Osa Peninsula dates back to 1948, and is a significant part of local development. By understanding its current state, improvement opportunities can be identified for cattle breeding farms. Objective: To characterize bovine production in Bahia Drake and Puerto Jimenez, Puntarenas, Costa Rica. Methodology: We visited production systems from August 2017 to April 2018, and made interviews on producers, land, herd and other aspects. Results: We evaluated 43 production systems in P. Jimenez and 27 in Drake. In P. Jimenez, 81% of the people in charge of the farm were men and 95% landowners (mean: 35 years of experience). Mean farm size was 88ha, with 63% of the area dedicated to pasture. Mean herd size was 77 animals, with an animal load of 1,61AU/ha. Corresponding values for Bahía Drake were 89% men, 95% landowners, 25 year experience; 79ha, with 39% pasture; 44 animals, and 1,21UA/ha. Conclusion: At both sites, most of the people in charge are male owners, and there are no marked differences in farms or herds between sites. PubDate: 2023-07-21 DOI: 10.22458/urj.v15i2.4578 Issue No:Vol. 15, No. 2 (2023)
Authors:Henry Castro-Alvarado, Gabriela Davidovich-Young, Eric Wong-González Pages: e4685 - e4685 Abstract: Introduction: Eggs are one of the main foods providing nutrients to the world population, however, they rapidly loose quality. For the egg industry it would be beneficial to have technological alternatives to increase the shelf life, such as coatings that are applied to prevent quality loss. Objective: To evaluate the effect of the application of oil coatings on the physicochemical, microbiological, and sensory quality of hen eggs during storage. Methods: We applied, by immersion, coatings of deodorized medicinal grade mineral oil or palm and soybean olein with TBHQ 0,02% to category A Isa Brown hen eggs from a local producer, without prior cleaning, washing or disinfection. After a 6-hour drainage, we stored eggs at 21°C and 43% RH. We measured selected quality parameter every 7 days for a total of 42 days and statically compared trends over time for coated and uncoated eggs. Sensory analysis was also carried out using paired comparisons tests for fresh and coated eggs stored for a certain time. We used a hedonic scale for general acceptance of coated and uncoated eggs after 35 days of storage. Results: The evaluated coatings did not affect the normal behavior of the color and pH of the yolk, the Haugh units, the resistance to rupture and the total aerobic and yeast and mold counts during storage, while retarding the deterioration related to the yolk index, pH of the white and overall mass loss. In addition, the application of the coatings helped keep flavor perception of stored eggs when compared with fresh eggs; resulted in eggs with the same smell and adhesiveness as the uncoated egg; gave shine, and did not negatively influence external sensory acceptance. Conclusion: The shelf life of eggs during storage can be extended with the application of mineral or palm oil coatings. PubDate: 2023-07-20 DOI: 10.22458/urj.v15i2.4685 Issue No:Vol. 15, No. 2 (2023)
Authors:Lourdes Arce Espinoza, Karla Rojas Sáurez Pages: e4660 - e4660 Abstract: ABSTRACT. “Effect of age, sex and academic level in the practice of physical exercise”. Introduction: Physical exercise is related to various motivational factors, including: health, physical appearance, enjoyment and socialization. These motivational factors are different between men and women. Costa Rica ranks second in Central America for overweight and obesity, and has higher than average values for sedentary lifestyle. Objective: To identify the variables associated with the motivation to do physical exercise in the staff of a state university in Costa Rica. Methods: We applied an online survey to all university staff (N=3,998); it was online from October 1, 2021 to March 1, 2022. Of the 1779 answered, 71% reported some form of exercise. Results: The motivations for exercising were reported as health, physical appearance and enjoyment (stronger in younger people). Men more often reported health, while women cited enjoyment. Overall, health was the most relevant in all age groups, with values increasing over the years. Conclusion: Health and enjoyment were reported as key motivators for exercise, with health increasing in importance as people age. PubDate: 2023-07-19 DOI: 10.22458/urj.v15i2.4660 Issue No:Vol. 15, No. 2 (2023)
Authors:Paola Fuentes-Schweizer, Eric Morales Mora, Vargas Muñoz Vargas Muñoz, Kenia Barrantes Jiménez, Luz Chacón Jiménez Pages: e4656 - e4656 Abstract: “Physical, chemical, and microbiological characteristics of groundwater in Los Chiles, Costa Rica, and its association with land use”. Introduction: Los Chiles has one of the lowest Social Progress Indexes in Costa Rica. The inhabitants drink untreated groundwater from an aquifer across the Nicaragua-Costa Rica border. Objective: To characterize water quality and possible associations with land use. Methods: We collected six water samples from wells during the dry and rainy seasons in 2019 and applied standard tests. Results: Grasslands and bare ground cover larger areas than other land uses. The water is calcic-bicarbonate type, and its physical-chemical values are acceptable, we did not detect Escherichia coli in any sample, while we only detected fecal coliforms in La Trocha. Conclusion: If treated to eliminate coliforms and protected from other effects of human activity, this water will be optimal for human consumption. PubDate: 2023-06-30 DOI: 10.22458/urj.v15i2.4656 Issue No:Vol. 15, No. 2 (2023)
Authors:Andrew Lindwedel Cruz, Alejandro Durán Apuy Pages: e4636 - e4636 Abstract: Introduction: There are no previous studies about the Achiote Interurban Biological Corridor, Costa Rica. Objective: To characterize birds and land use to improve the corridor’s functional connectivity. Methods: We selected ten sampling sites (sugar cane and coffee cultivation areas, urban areas, secondary forest, and riparian forest) and used the point count technique for six months (100 sampling hours and 120 samples). We determined bird richness and abundance associated with each type of cover. Results: We identified 194 bird species. Secondary forest, riparian areas, and coffee plantations had the highest diversity. Trophic guilds and habitat use were not related to cover, and insectivores and frugivores were generally dominant. Conclusion: Birds with generalist habits predominated in open areas and forest patches within the biological corridor. PubDate: 2023-06-29 DOI: 10.22458/urj.v15i2.4636 Issue No:Vol. 15, No. 2 (2023)
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