39 research outputs found
Constraining the evolution of stellar rotation using solar twins
The stellar Rotation Age relation is commonly considered as a useful
tool to derive reliable ages for Sun-like stars. However, in the light of
\kepler\ data, the presence of apparently old and fast rotators that do not
obey the usual gyrochronology relations led to the hypothesis of weakened
magnetic breaking in some stars. In this letter, we constrain the solar
rotation evolutionary track using solar twins. Predicted rotational periods as
a function of mass, age, [Fe/H] and given critical Rossby number () were estimated for the entire rotational sample. Our analysis favors
the smooth rotational evolution scenario and suggests that, if the magnetic
weakened breaking scenario takes place at all, it should arise after or ages 5.3 Gyr (at 95 confidence level).Comment: 5 pages, 3 figures, accepted for publication in MNRA
Cryopreservation of Domestic and Wild Animal Spermatozoa: Update of Knowledge
Current sperm cryopreservation protocols for domestic and wild mammals aim to minimize the cryogenic damage caused by cell dehydration, ice formation, and osmotic stress. The optimization of sperm cryopreservation include the use of different synthetic and nonsynthetic-based extenders supplemented with additives (e.g., egg yolk, coconut water, etc.) and antioxidants (e.g., melatonin, L-carnitine, caffeine, resveratrol, etc.) that protect the plasmalemma, acrosome, and mitochondria against the detrimental effects caused by the cryopreservation process. Furthermore, the use of penetrating (e.g., glycerol, ethylene glycol, dimethylformamide, etc.) and nonpenetrating (e.g., sucrose and trehalose) cryoprotectant agents (CPAs) or their combination should be investigated to protect sperm during the freezing process in slow and ultra-rapid freezing procedures. Finally, new cryopreservation protocols should focus on freezing curves and initial cooling rates that allow optimal dehydration during freezing and adequate hydration during thawing. The suitable interaction of all these factors will allow a sperm subpopulation to survive cryopreservation with integrity and fertilizing capacity, contributing to the improvement of the efficiency of genetic resource management and the development of germplasm banks that support the preservation of genetic diversity in domestic and wild animals
Algarroba Effects on Behavior and Dairy Production of Grazing Cows II. Rainy Season.
The influence of arborization with algarroba (Prosopis juliflora SW) on behavior and dairy production of grazing cows was evaluated. The trial was made in the rainy season, and six enclosures per arborization treatment were used (low arborization, with 1-7 trees/ha; mid-arborization, with 12-16 trees/ha; and high arborization, with 20-27 trees/ha). Activities were observed every ten minutes during the mornings and afternoons. The number of animals, and each animal´s activity time was recorded. The dairy production data were collected and compared through a randomized design with six repetitions (ANOVA). Significant differences were observed (P < 0.05) to more arborization in grazing (155-173 min), and the monthly values observed were similar. In fields with low arborization, the cows ate less grass, whereas fields with mid and high arborization, the cows grazed longer, and produced more milk (11.2 and 12.59 kg/c/day)
Percepciones de productores sobre el bienestar de bovinos doble propósito en los llanos Orientales de Colombia
The aim of this observational-cross-sectional study was to determine the attitudes of producers regarding the welfare (CW) of double-purpose (DP) cattle. A face-to-face survey was carried out with 20 DP producers from Meta, Colombia to quantify their perceptions (using 5-point Likert scales) on the level of impact that environmental, health and management aspects have on CW and on the level of importance of indicators (environmental, management, health and affective states) of CW evaluation. The average scores awarded to each aspect and indicator were calculated. The Kruskal-Wallis test was used to assess differences between categories of impact aspects and between categories of indicators. The health aspects were considered the ones with had the greatest impact (4.07/5), while the indicators of affective states were considered the least important (3.82). The key aspects categorized as 'Extreme Impact' factors were external parasite load (4.65), not checking colostrum intake (4.65), heat stress (4.55), myiasis (4.25) and disbudding/dehorning without anesthesia (4.25). Key indicators recognized as 'Essential' were access to shade (4.65), colostrum intake (4.55), staff skills (4.5), pup mortality (4.45) and drinking water (4.45). The results highlight the existing consensus between the impact of heat stress and the importance of the presence of shade as an indicator of CW, as well as between colostrum consumption and calf mortality. Likewise, there is evidence of a disagreement between the high impact of disbudding /dehorning without anesthesia and the low level of importance perceived as an essential indicator of CW.El objetivo de este estudio observacional-transversal fue determinar las actitudes de productores sobre el bienestar de bovinos (BB) doble-propósito (DP). Se realizó una encuesta presencial a 20 productores DP del Meta, Colombia, para cuantificar sus percepciones (utilizando escalas Likert de 5-puntos) sobre el nivel de impacto que tienen aspectos ambientales, de salud y de manejo en el BB y sobre el nivel de importancia de indicadores (ambientales, manejo, salud y estados afectivos) de evaluación del BB. Se calcularon las puntuaciones promedio otorgadas a cada aspecto e indicador. La prueba Kruskal-Wallis se utilizó para evaluar diferencias entre categorías de aspectos de impacto y entre categorías de indicadores. Los aspectos de salud fueron considerados como los de mayor impacto (4.07/5), mientras que los indicadores de estados afectivos fueron considerados como los de menor importancia (3.82). Los aspectos clave categorizados como factores de ‘Impacto extremo’ fueron carga parasitaria externa (4.65), no verificar consumo de calostro (4.65), estrés térmico (4.55), miasis (4.25) y topizar/descornar sin anestesia (4.25). Los indicadores clave reconocidos como ‘Esenciales’ fueron acceso a sombra (4.65), consumo de calostro (4.55), capacidades del personal (4.5), mortalidad de crías (4.45) y agua potable (4.45). Los resultados resaltan el consenso existente entre el impacto del estrés calórico y la importancia de la presencia de sombra como indicador de BB, así como entre el consumo de calostro y la mortalidad de crías. Asimismo, se evidencia un disenso entre el alto impacto que tiene topizar/descornar sin anestesia y el bajo nivel de importancia percibido como indicador esencial de BB
Análisis morfométrico y funcional de ovocitos bovinos obtenidos de ovarios de matadero y por aspiración folicular transvaginal en vacas criollas del altiplano ecuatoriano
This study assessed the morphometric and functional characteristics of oocytes from 10 native cows to the Ecuadorian Andes, collected by transvaginal follicular aspiration (OPU) and oocytes collected post mortem (PM) from abattoir ovaries. For this purpose, 1157 cumulus-oocyte complexes (CCOs) of the OPU group (n=271) and PM group (n=886) were recovered in 10 repetitions per group by follicular aspiration at 90 mm Hg pressure and classified as A, B or C, according to the characteristics of the cytoplasm and cumulus cells. The activity of the enzyme glucose 6 phosphate dehydrogenase (G6PD) was determined as an indicator of follicular growth and maturation and the integrity of the plasma membrane by staining the CCOs with cresyl brilliant blue (BCB +) and trypan blue, respectively. The size (diameter and volume) of the oocytes was evaluated using CaptaVisio® software v. 5.1. The data were analysed by logistic regression and by the SAS general linear model, and the means were compared by the least square method. The results showed that the oocytes of the PM group had a larger diameter (126.0 ± 0.48 vs. 122.7 ± 0.79 µm; p<0.01) and integrity of the plasma membrane (86.0 vs. 76.8%; p<0.05) than the OPU group. However, quality A and B oocytes did not show significant differences between groups with respect to plasma membrane integrity and BCB + values. The results suggest that, although the fact that the size and viability were more affected in the oocytes aspirated by OPU, those of quality A and B from both sources showed similar values regarding the integrity of the plasma membrane and metabolic condition to continue. maturation.El estudio analizó las características morfométricas y funcionales de ovocitos de 10 vacas nativas de los Andes ecuatorianos, colectados por aspiración folicular transvaginal (OPU) y de ovocitos colectados post mortem (PM) de ovarios de matadero. Para este propósito, 1157 complejos cúmulo-ovocito (CCOs) del grupo OPU (n=271) y PM (n=886) fueron recuperados en 10 repeticiones por grupo por aspiración folicular a 90 mm Hg de presión y clasificados en calidad A, B o C, de acuerdo con las características del citoplasma y células del cúmulo. Se determinó la actividad de la enzima glucosa 6 fosfato deshidrogenasa (G6PD) como indicador de crecimiento folicular y maduración finalizado y la integridad de la membrana plasmática tiñendo los CCOs con azul brillante de cresilo (BCB+) y azul de tripán, respectivamente. Se evaluó el tamaño (diámetro y volumen) de los ovocitos usando un software CaptaVisionÒ (v. 5.1). Los datos se analizaron por regresión logística y por el modelo lineal general del SAS, y las medias se compararon por el método de los mínimos cuadrados. Los resultados mostraron que los ovocitos del grupo PM presentaron mayor diámetro (126.0±0.48 vs 122.7±0.79 µm; p<0.01) e integridad de la membrana plasmática (86.0 vs 76.8%; p<0.05) que el grupo OPU. Sin embargo, los ovocitos de calidad A y B no registraron diferencias significativas entre grupos con respecto a la integridad de la membrana plasmática y valores de BCB+. Los resultados sugieren que, a pesar de que el tamaño y la viabilidad fue más afectada en los ovocitos aspirados por OPU, los de calidad A y B provenientes de ambas fuentes mostraron valores similares con respecto a la integridad de la membrana plasmática y condición metabólica para proseguir la maduración
Influencia del algarrobo en la conducta y producción de leche de vacas en pastoreo. I I . Período l luvioso
Se evaluó la influencia de la arborización con algarrobo (Prosopis juliflora SW) en la conducta y producción de leche de vacas en pastoreo. El ensayo se realizó en época de lluvia y se utilizaron seis cuartones por tratamiento de arborización (bajo grado de arborización con 1-7 árboles/ha; medio grado de arborización con 1 2- 1 6 árboles/ha y alto grado de arborización 20-27 árboles/ha. En la mañana y en la tarde se observaban las actividades cada 1 0 min. Se registró el tiempo del animal en actividad, el número de animales . Se tomó la información de la producción de leche/tratamiento y en un diseño al azar con seis repeticiones se comparó mediante Anava. Se registraron diferencias significativas (P < 0, 05) a favor de mayor arborización en pastoreo ( 1 55- 1 73 min) y los índices tuvieron un comportamiento muy similar por meses. En potreros con baja carga arbórea las vacas consumen menos pasto, mientras que en potreros con medio y alto grado de arborización, las vacas pastaron más tiempo y tuvieron mayor producción de leche con valores entre 1 1 , 02 y 1 2, 50 kg/v/día. Effect of Algarroba on Grazing Cow Behavior and Milk Production. II. Rainy Season ABSTRACTThe effect of algarroba (Prosopis juliflora SW) arborization on grazing cow behavior and milk production was assessed. The trial was made in the rainy season, and six enclosures were used per arborization treatment (low arborization, 1 -7 trees/ha; mid arborization, 1 2- 1 6 trees/ha; high arborization, 20-27 trees/ha) . The time of each animal during activity, and the number of animals, were registered. Milk production values were compared using ANOVA, following a randomized design with six replicas. The significant differences were registered (P < 0. 05) positively toward greater arborization grazing ( 1 55- 1 73 min) , and the indexes had a very similar behavior for months. In poorly arborized grazing lands cows consumed less pasture, whereas in highly arborized lands, cows stayed longer and pro-duced more milk ( 1 1 . 02 and 1 2. 50 kg/cow/day).
One Welfare for all: Associations between sheep welfare indicators and producers’ mental health
Objective. The objective of this observational cross-sectional study was to investigate associations between farmers’ mental health scores for stress, anxiety, depression, and resilience, and sheep welfare outcomes. Materials and methods. Twenty-two sheep farms in the departments of Boyacá, Cundinamarca, Tolima, and Meta, Colombia, were visited once. Clinical health, cleanliness, and calmness of randomly selected sheep per farm were scored to identify the number of animals with different welfare problems such as lameness, hoof overgrowth, and mastitis. A face-to-face interview with the farmer was done to gather demographic information (farm size and year of establishment, gender, age, role at the farm, and education) and to complete validated psychometric scales to assess resilience, stress, anxiety, and depression. Linear regression models were used to evaluate associations between farmers’ mental health scores, demographic aspects, and within-flock prevalence of sheep welfare indicators. Results. A total of 427 sheep were evaluated across farms. The most prevalent welfare problems identified were hoof overgrowth (40.9%) and dirty fleece (32.9%), while the least prevalent were clinical mastitis (1.3%) and respiratory issues (1.2%). Farmers’ stress level was positively associated with the prevalence of clinically lame sheep and farm size. Anxiety was positively associated with the prevalence of sheep with dirty fleece, clinical lameness, and with being a female farmer. Depression was positively associated with the prevalence of hoof overgrowth. Conclusions. Findings showed that higher levels of stress, anxiety, and depression among farmers were associated with the presence of animal welfare problems, larger farms, and gender
Modified Wisconsin Card Sorting Test (M-WCST): Normative data for Spanish-speaking pediatric population
OBJECTIVE: To generate normative data for the Modified Wisconsin Card Sorting Test (M-WCST) in Spanish-speaking
pediatric populations.
METHOD: The sample consisted of 4,373 healthy children from nine countries in Latin America (Chile, Cuba, Ecuador,
Guatemala, Honduras, Mexico, Paraguay, Peru, and Puerto Rico) and Spain. Each participant was administered the M-WCST
as part of a larger neuropsychological battery. Number of categories, perseverative errors, and total error scores were normed
using multiple linear regressions and standard deviations of residual values. Age, age2, sex, and mean level of parental
education (MLPE) were included as predictors in the analyses.
RESULTS: The final multiple linear regression models indicated main effects for age on all scores, such that the number
of categories correct increased and total number of perseverative errors and total number of errors decrease linearly as a
function of age. Age2 had a significant effect in Chile, Cuba, Ecuador, and Spain for numbers of categories; a significant
effect for number of perseverative errors in Chile, Cuba, Mexico, and Spain; and a significant effect for number of total
errors in Chile, Cuba, Peru, and Spain. Models showed an effect for MLPE in Cuba (total errors), Ecuador (categories and
total errors), Mexico (all scores), Paraguay (perseverative errors and total error), and Spain (categories and total errors). Sex
affected number of total errors for Ecuador.
CONCLUSIONS: This is the largest Spanish-speaking pediatric normative study in the world, and it will allow neuropsychologists from these countries to have a more accurate way to interpret the M-WCST with pediatric populations
Modified Wisconsin Card Sorting Test (M-WCST): Normative data for Spanish-speaking pediatric population
OBJECTIVE: To generate normative data for the Modified Wisconsin Card Sorting Test (M-WCST) in Spanish-speaking pediatric populations. METHOD: The sample consisted of 4,373 healthy children from nine countries in Latin America (Chile, Cuba, Ecuador, Guatemala, Honduras, Mexico, Paraguay, Peru, and Puerto Rico) and Spain. Each participant was administered the M-WCST as part of a larger neuropsychological battery. Number of categories, perseverative errors, and total error scores were normed using multiple linear regressions and standard deviations of residual values. Age, age2, sex, and mean level of parental education (MLPE) were included as predictors in the analyses. RESULTS: The final multiple linear regression models indicated main effects for age on all scores, such that the number of categories correct increased and total number of perseverative errors and total number of errors decrease linearly as a function of age. Age2 had a significant effect in Chile, Cuba, Ecuador, and Spain for numbers of categories; a significant effect for number of perseverative errors in Chile, Cuba, Mexico, and Spain; and a significant effect for number of total errors in Chile, Cuba, Peru, and Spain. Models showed an effect for MLPE in Cuba (total errors), Ecuador (categories and total errors), Mexico (all scores), Paraguay (perseverative errors and total error), and Spain (categories and total errors). Sex affected number of total errors for Ecuador. CONCLUSIONS: This is the largest Spanish-speaking pediatric normative study in the world, and it will allow neuropsychologists from these countries to have a more accurate way to interpret the M-WCST with pediatric populations