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546,196 artículos
Año:
2022
ISSN:
1815-5936
Peraza-Hernández, Mirneirys; Piñero-Rodríguez , Abel
Universidad Tecnológica de La Habana "José Antonio Echeverría", Cujae
Resumen
In the work, is present a diagnosis made in the company Acinox Comercial for competency profiles determination of the cadres positions, based on the policy improvement defined by the Communist Party of Cuba for the Work System with the Tables of the State, the Government and their Reserves, with the objective of guaranteeing the projection, selection, evaluation and promotion of the cadres, on whom the solidity and continuity of the country's development depends. Having well-defined profiles for the positions of cadres in an organization constitutes the basis for the implementation and development of the approved policy.
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Año:
2022
ISSN:
1815-5936
Asadobay-Escobar, Joffre Fabian; Perero-Espinoza, Galo Arturo
Universidad Tecnológica de La Habana "José Antonio Echeverría", Cujae
Resumen
Inadequate management of hospital solid waste; the article evaluation of hospital solid waste management at the Jerusalén clinic in the city of Riobamba was carried out; using the evaluation matrix model of the Ministry of Public Heath of Ecuador created in 2019,for all public and private health entities in the country; the result will allow to know if it meet the conditions regarding the good management of solid waste, reaching the fundamental conclusion that there is a disagreement in the different hospitals and clinics both in their management and in their final disposal; failing to comply with current environmental legislation.
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Año:
2022
ISSN:
0718-560X, 0718-560X
González-Meza, Georgia Maria; Herrera-Castro, Karla; Casillas-Hernández, Ramón; Rentería-Mexía, Ana; Gortáres-Moroyoqui, Pablo; Gil-Núñez, Juan C.; Ibarra-Gámez, José; Ulloa-Mercado, Gabriela
Pontificia Universidad Católica de Valparaíso
Resumen
Microalgae are a promising solution in shrimp farming overexploitation. This study assessed the efficacy of microalgae as a food additive for Penaeus vannamei growth and their effect on immune system stimulation against Vibrio parahaemolyticus. Three diets were formulated with 0, 1, and 3% (DC, D1, and D3, respectively) of a mixture of three different microalga species, Tetraselmis suecica, Dunaliella salina, and Chaetoceros muelleri, and growth, survival, and post-harvest quality in shrimp culture were evaluated. Two bioassays were performed: a 60-day feeding trial and an immersion infection bioassay against V. parahaemolyticus. D1 was the best treatment and significantly different to DC (P ≤ 0.05), achieving a food conversion factor of 1.24 ± 0.11 and 1.85 ± 0.38; specific growth rate 1.58 ± 0.03% d-1 and 1.35 ± 0.11% d-1; and weight gain of 5.68 ± 0.32 g and 4.79 ± 0.33 g, respectively. Protein content in shrimp muscle was positively increased by microalgae inclusion, achieving 20.8 ± 0.2% (D1) to 21.7 ± 0.3% (D3), 19.2 ± 0.1% (DC). In the infection bioassay, D1 and D3 reached a 100% survival rate, and histological damage in the hepatopancreas was not observed, suggesting immune system stimulation. These results indicated that microalgae added to food are an excellent source of proteins, carbohydrates, lipids, and promoters of antimicrobial activity that allowed additional protection against mortality caused by V. parahaemolyticus.
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Año:
2022
ISSN:
0718-560X, 0718-560X
Carvalho, Barbara M.; Oliveira Freitas, Matheus; Lapuch, Isabel; Volpedo, Alejandra V.; Vitule, Jean R.S.
Pontificia Universidad Católica de Valparaíso
Resumen
Invasive species are among the most important problems for biodiversity conservation worldwide, particularly in megadiverse countries such as Brazil. However, there is no biological information to develop policies for managing invasive species populations in many cases. The life history parameters and otolith variations are essential to understanding the adaptations of the species introduced in marine environments. This study aimed to identify the age structure and ontogenetic variation in the sagitta otolith of Opsanus beta. Fish samples were obtained monthly in the Paranaguá Estuarine Complex (PEC), south of Brazil. The shape indices verified ontogenetic variations in the otoliths (PERMANOVA; F = 110; P < 0.0001), but no sexual variations were observed in the shape of the otoliths (PERMANOVA; F = 3.65; P > 0.05). Specimen aged between 1 to 9 years were observed in the PEC, with the highest occurrence of individuals between 3 and 6 years (78%). No sexual differences were observed between the ages by the Kimura test. Our results confirm that the O. beta population is well established with age groups similar to that observed in the region where the species is native.
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Año:
2022
ISSN:
0718-560X, 0718-560X
Vivanco-Aranda, Miroslava; Tanahara-Romero, Sorayda Aimé; Lugo-Ibarra, Karina Del Carmen; Del Rio-Zaragoza, Oscar Basilio
Pontificia Universidad Católica de Valparaíso
Resumen
The Pacific mackerel Scomber japonicus aquaculture is receiving growing attention, and further development of this industry is expected to protect wild stocks. Information on S. japonicus hematology is very limited. Therefore, the present study aimed to provide the hematological and serum chemistry profiles associated with sex and some seasonal variations in Pacific mackerel from Todos Santos Bay, Baja California, Mexico. Fish were sampled in April (spring) and August (summer). Results showed that the condition factor and all blood parameters analyzed in male and female mackerel were not affected by sex (P > 0.05). The seasonality effect on the mackerel was observed in some blood parameters such as mean corpuscular hemoglobin, total protein, globulin, and triglycerides that exhibited lower values in April compared to August (P < 0.05). While white blood cell count was higher in August (P < 0.05) compared with April. The fish sampled during the two sampling times were possibly a heterogeneous group of ages (1 to 3 years) with lengths ranging from 20 to 30 cm. Consequently, there is an urgent need to follow doing reference interval databases to assess Pacific mackerel health status under different conditions.
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Año:
2022
ISSN:
0718-560X, 0718-560X
Báez, Pedro; Araneda, Cristián; Burns, Ludovic; Navarrete, Claudia
Pontificia Universidad Católica de Valparaíso
Resumen
A male specimen of the Aesop slipper lobster Scyllarides haanii was found in the coastal vicinity of Ahu Tongariki (27°07'33"S, 109°16'37"W), Rapa Nui. Its taxonomic determination was carried out by a detailed morphological examination and a DNA barcoding identification analysis by sequencing the cytochrome oxidase subunit 1 (COX1) gene. S. haanii has a wide geographic distribution with occasional presence from the Indo-Pacific to the Hawaiian Archipelago, including the Red Sea, Japan, Korea, China, Taiwan, Indonesia, Australia, Reunion, and French Polynesia; from 10 to 135 m of depth, preferably on rocky bottoms. This record extends the geographical distribution of S. haanii to Rapa Nui. It increases to five the species number of marine lobsters present on the island: a Palinuridae, Panulirus pascuensis and four Scyllaridae, Parribacus perlatus, Arctides regalis, Scyllarides roggevenni, and now S. haanii. This finding derived from the local initiative Pilotos to promote the sustainable management of coastal species, led by the Rapa Nui Sea Council ("Koro Nui o te Vaikava"), the elected authority in charge of the co-administration of Multiple Uses Marine Protected Area (MUMPA). The specimen will be deposited in the Crustacean Collection of the MNHNCL: accession number in GenBank (MW699539.1).
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Año:
2022
ISSN:
0718-560X, 0718-560X
Veranes-Dip, Anabel; Moreno-Sánchez, Xchel Gabriel; Abitia-Cárdenas, Leonardo Andrés; Villalejo-Fuerte, Marcial Trinidad; Irigoyen Arredondo, Marina Soledad
Pontificia Universidad Católica de Valparaíso
Resumen
The Pacific porgy Calamus brachysomus (Lockington, 1880) is exploited for local consumption and commerce in Baja California Sur (BCS). Monthly samples to study its reproductive biology were obtained from the artisanal fishery operating in Santa Rosalía, BCS, Mexico, from July 2015 to July 2016. A total of 265 specimens were analyzed, including 147 females and 118 males. The sexual proportion (1.24F:1M) did not differ from the expected 1:1 proportion (P = 0.08). There were no significant differences between sexes in total length (P = 0.94). Variations in the hepatosomatic index and condition factor indicated that food constituted the main energy source during reproduction, with possible additional use of endogenous reserves originating in the liver during spawning. The gonads histological analysis indicated an asynchronous ovarian development and batch spawning strategy. There were spawning capable females during 11 of the 13 sampled months; the exceptions were February and September, coinciding with minimum and maximum sea surface temperature (SST) values. These results, along with the gonadosomatic index variations, allowed us to conclude that C. brachysomus reproduces over a large part of the year with an activity peak from May to July, in an SST interval of 21 to 28ºC.
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Año:
2022
ISSN:
0718-560X, 0718-560X
Peraza-Yee, Mario Martin; Carranza-Díaz, Otoniel; Bermudes-Lizárraga, José Francisco; López-Peraza, Diana Judith; Nieves-Soto, Mario; Millán-Almaraz, Martha Irene
Pontificia Universidad Católica de Valparaíso
Resumen
This work aims to evaluate its effect on cell density, biomass, and proximal composition in semicontinuous cultures. Thalassiosira weissflogii was cultivated in five culture media, for which the f medium was taken as reference, and the concentrations of nitrates, phosphates, and silicates were modified up to a factor of four in five treatments (f/4, f/2, f, 2f, and 4f). Cell density and biomass increased as the initial nutrients rose in the treatments. Protein and lipids (mg L-1) in the biomass of T. weissflogii were higher in the 2f and 4f treatments for the three partial harvests. The lipid biomass in the cultures was higher than with proteins and carbohydrates for all treatments, with 2f and 4f being the most concentrated. The concentration of nitrates, phosphates, and silicates of the culture media, declined as the cell density increased in all cultures, decreasing more than 90% in phosphates and 94-98% for the silicates for the initial concentrations. At the cell level, the percentage of carbohydrates related to dry weight in T. weissflogii increased as the level of the f treatment decreased. Meanwhile, the protein fraction declined when the level of the f medium was either increased or decreased. The data reported in this study can be useful for producing T. weissflogii in a 30% semicontinuous system, obtaining more controlled biomass production per day with an estimated value of its proximal composition, based on the level of the f medium.
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Año:
2022
ISSN:
0718-560X, 0718-560X
Ascencio-Michel, Roberto; Ibarra, Ana María; Araneda-Padilla, Marcelo; Ponce-Díaz, Germán; Vergara-Solana, Francisco Javier
Pontificia Universidad Católica de Valparaíso
Resumen
The Pacific oyster Crassostrea gigas was introduced in northwestern Mexico for aquaculture purposes. Although its cultivation has been successful, this species has shown high mortalities during summer. To mitigate this problem, producers have resorted to biotechnology (triploidy), whose performance -regarding diploid seedling- depends on site conditions and stocking time. Hence, uncertainty exists on its benefits under real production conditions. This research evaluates triploidy performance by implementing a dynamic simulation model considering environmental effects (temperature and chlorophyll) on culture production. The dynamic simulation was based on systems theory, dividing the productive system into two sub-models (environmental and biological), including temperature and chlorophyll effects, growth, mortality, and condition index parameterized in the function of the environmental parameters. The dynamic simulation results suggest that implementing triploid culture is advantageous in zones under high stress associated with high temperature and low productivity; likewise, triploid spat tends to show better performance independently of the site. Nevertheless, performance by ploidy varies depending on the environmental conditions of the sites.
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Año:
2022
ISSN:
0718-560X, 0718-560X
Vögler, Rodolfo; Sellanes, Javier; Gorny, Matthias; Milessi, Andrés C.
Pontificia Universidad Católica de Valparaíso
Resumen
The conservation of threatened sharks requires defining the occurrence and distribution range of the species and key habitats for their survival. During surveys of mesophotic and deeper benthic habitats (50 to 340 m depth) off Rapa Nui (Easter Island, Chile, southeastern Pacific), using a remotely operated vehicle, a male bluntnose sixgill shark, Hexanchus griseus (Hexanchidae), was sighted. The estimated total length of this immature specimen was ~146 cm. This is the first documented record of the species off Rapa Nui. The in situ evidence of this threatened deep-water shark highlights the urgency to build management strategies to protect vulnerable apex predators of coastal and deep-waters ecosystems of the recently created Rapa Nui Marine Protected Area for Multiple Uses, above all from the effects of fisheries and other human activities (e.g. bycatch, marine litter).
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