The Resilient Dairy Genome Project-A general overview of methods and objectives related to feed efficiency and methane emissions.

The Resilient Dairy Genome Project (RDGP) is an international large-scale applied research project that aims to generate genomic tools to breed more resilient dairy cows. In this context, improving feed efficiency and reducing greenhouse gases from dairy is a high priority. The inclusion of traits related to feed efficiency (e.g., dry matter intake [DMI]) or greenhouse gases (e.g., methane emissions [CH4]) relies on available genotypes as well as high quality phenotypes. Currently, 7 countries (i.e., Australia, Canada, Denmark, Germany, Spain, Switzerland, and United States) contribute with genotypes and phenotypes including DMI and CH4. However, combining data are challenging due to differences in recording protocols, measurement technology, genotyping, and animal management across sources. In this study, we provide an overview of how the RDGP partners address these issues to advance international collaboration to generate genomic tools for resilient dairy. Specifically, we describe the current state of the RDGP database, data collection protocols in each country, and the strategies used for managing the shared data. As of February 2022, the database contains 1,289,593 DMI records from 12,687 cows and 17,403 CH4 records from 3,093 cows and continues to grow as countries upload new data over the coming years. No strong genomic differentiation between the populations was identified in this study, which may be beneficial for eventual across-country genomic predictions. Moreover, our results reinforce the need to account for the heterogeneity in the DMI and CH4 phenotypes in genomic analysis.

Sol-gel synthesis of Eu3+ doped silica-gold nanorod composites with tunable optical properties.

Gold nanorods (AuNRs) suspension at various concentrations was added into the sol-gel process to engineer nanostructured europium-doped silica host matrices as light-emitting composites. For this purpose, the samples were prepared following two different routes depending on the chemicals used as dopant and catalyst: (a) Eu(NO3)3·5H2O and HNO3, and (b) EuCl·6H2O and HCl. In any case, samples adding various concentrations of AuNRs suspension were prepared. The structural characterization of the samples was through STEM, backscattered electrons (BSE), and EDS analysis. Additionally, their optical properties were evaluated by PL spectroscopy and CIE colorimetry. The results confirmed that (a) methodology produced samples with AuNRs embedded and randomly distributed in the samples. However, these features were not observed in the samples obtained through (b) due to AuNRs dissolution in HCl media. Regarding the optical properties, the analysis of the relative intensity ratio 5D0 → 7F2/5D0 → 7F1 suggested that Eu3+ ions occupy non-centrosymmetric sites in (a) host matrices and centrosymmetric sites in (b). Hence, the increase of AuNRs suspension when fabricating (a) host matrices produced remarkable color changes in the luminescence of the samples towards the reddish-orange region. Meanwhile, the dissolution of AuNRs in (b) minimized the localized surface plasmon resonance (LSPR) effects on the Eu3+ luminescence. These findings revealed that the evaluation and selection of chemicals are critical factors when engineering these materials for more efficient coupling between the LSPR and Eu3+ luminescence.

Prueba de caminata de 6 minutos: del sujeto normal a la obesidad mórbida / Six minute walk test: from normal to morbid obesity subject

Resumen Introducción: La obesidad mórbida se asocia a alteraciones de la capacidad de caminar, sin embargo se desconoce cómo es el comportamiento de la prueba de caminata de 6 minutos en sujetos con incrementos del índice de masa corporal (IMC). Objetivo: Describir el comportamiento de la prueba de caminata de 6 minutos en sujetos con IMC normal hasta la obesidad mórbida. Métodos: Mediante un diseño transversal analítico se estudiaron sujetos de ambos sexos de 18 a 60 años con IMC: normal (18.5-24.9 kg/m2), sobrepeso (25-29.9 kg/m2), obesidad (30-39.9 kg/m2), obesidad mórbida (> 40 kg/m2). Se les realizó prueba de caminata de 6 minutos, se acotaron variables demográficas y antecedentes personales patológicos. Se analizaron las categorías de IMC con ANOVA de una vía y ajuste de Bonferroni y los sexos con prueba t, ambos para grupos independientes y correlaciones de Pearson para las diversas variables. Una p < 0.05 fue considerada estadísticamente significativa. Resultados: Se estudiaron 480 sujetos de ambos sexos en cuatro grupos. Edad: hombres 43 ± 11 y mujeres 45 ± 10 años. Porcentaje diabetes mellitus (6.7%), hipertensión arterial (18.3%). Metros caminados hombres vs. mujeres por IMC (normal: 483 ± 56 vs. 449 ± 61; sobrepeso: 471 ± 55 vs. 441 ± 44; obesidad: 455 ± 70 vs. 421 ± 47; obesidad mórbida: 443 ± 49 vs. 403 ± 54; p < 0.05). Correlación IMC-metros caminados r: -0.446 (p < 0.0001). Conclusiones: Los metros caminados en la prueba de caminata de 6 minutos disminuyeron conforme incrementó el IMC. El sexo masculino caminó más metros en todas las categorías.

Abstract Introduction: Morbid obesity is associated with alterations in the ability to walk, however, the behavior of the 6-minute walk test in subjects with increases in body mass index is unknown. Objective: To describe the behavior of the 6-minute walk test in subjects with normal body mass index to morbid obesity. Methods: Through an analytical cross-sectional design, subjects of both genders from 18 to 60 years old with body mass index were studied: Normal (BMI: 18.5-24.9); overweight (BMI: 25-29.9); obesity (BMI: 30-39.9); morbid obesity (BMI: > 40) kg/m2. A 6-minute walk test was performed, demographic variables and pathological personal history were delimited. BMI categories were analyzed with one-way ANOVA and Bonferroni adjustment, and gender with t-test, both for independent groups, and Pearson's correlations for the various variables. Results: 480 subjects of both genders were studied in four groups. Age: men 43 ± 11 and women 45 ± 10 years old. Percentage diabetes mellitus (6.7%), arterial hypertension (18.3%). Meters walked men vs. women by body mass index (normal: 483 ± 56 vs. 449 ± 61; overweight: 471 ± 55 vs. 441 ± 44; obesity: 455 ± 70 vs. 421 ± 47; morbid obesity: 443 ± 49 vs. 403 ± 54, p < 0.05). Correlation body mass index-meters walked: r: -0.446 (p < 0.0001). Conclusions: Meters walked in the 6-minute walk test decreased as body mass index increased. The male gender walked more meters in all categories.

Review: Diving into the cow hologenome to reduce methane emissions and increase sustainability.

Interest on methane emissions from livestock has increased in later years as it is an anthropogenic greenhouse gas with an important warming potential. The rumen microbiota has a large influence on the production of enteric methane. Animals harbour a second genome consisting of microbes, collectively referred to as the "microbiome". The rumen microbial community plays an important role in feed digestion, feed efficiency, methane emission and health status. This review recaps the current knowledge on the genetic control that the cow exerts on the rumen microbiota composition. Heritability estimates for the rumen microbiota composition range between 0.05 and 0.40 in the literature, depending on the taxonomical group or microbial gene function. Variables depicting microbial diversity or aggregating microbial information are also heritable within the same range. This study includes a genome-wide association analysis on the microbiota composition, considering the relative abundance of some microbial taxa previously associated to enteric methane in dairy cattle (Archaea, Dialister, Entodinium, Eukaryota, Lentisphaerae, Methanobrevibacter, Neocallimastix, Prevotella and Stentor). Host genomic regions associated with the relative abundance of these microbial taxa were identified after Benjamini-Hoschberg correction (Padj < 0.05). An in-silico functional analysis using FUMA and DAVID online tools revealed that these gene sets were enriched in tissues like brain cortex, brain amigdala, pituitary, salivary glands and other parts of the digestive system, and are related to appetite, satiety and digestion. These results allow us to have greater knowledge about the composition and function of the rumen microbiome in cattle. The state-of-the art strategies to include methane traits in the selection indices in dairy cattle populations is reviewed. Several strategies to include methane traits in the selection indices have been studied worldwide, using bioeconomical models or economic functions under theoretical frameworks. However, their incorporation in the breeding programmes is still scarce. Some potential strategies to include methane traits in the selection indices of dairy cattle population are presented. Future selection indices will need to increase the weight of traits related to methane emissions and sustainability. This review will serve as a compendium of the current state of the art in genetic strategies to reduce methane emissions in dairy cattle.

[Six minute walk test: From normal to morbid obesity subject]. / Prueba de caminata de 6 minutos: del sujeto normal a la obesidad mórbida.

Introduction: Morbid obesity is associated with alterations in the ability to walk, however, the behavior of the 6-minute walk test in subjects with increases in body mass index is unknown. Objective: To describe the behavior of the 6-minute walk test in subjects with normal body mass index to morbid obesity. Methods: Through an analytical cross-sectional design, subjects of both genders from 18 to 60 years old with body mass index were studied: Normal (BMI:18.5-24.9); overweight (BMI:25-29.9); obesity (BMI:30-39.9); morbid obesity (BMI:>40) kg/m2. A 6-minute walk test was performed, demographic variables and pathological personal history were delimited. BMI categories were analyzed with one-way ANOVA and Bonferroni adjustment, and gender with t-test, both for independent groups, and Pearson's correlations for the various variables. Results: 480 subjects of both genders were studied in four groups. Age: men 43 ± 11 and women 45 ± 10 years old. Percentage diabetes mellitus (6.7%), arterial hypertension (18.3%). Meters walked men vs. women by body mass index (normal: 483 ± 56 vs. 449 ± 61; overweight: 471 ± 55 vs. 441 ± 44; obesity: 455 ± 70 vs. 421 ± 47; morbid obesity: 443 ± 49 vs. 403 ± 54, p < 0.05). Correlation body mass index-meters walked: r: -0.446 (p < 0.0001). Conclusions: Meters walked in the 6-minute walk test decreased as body mass index increased. The male gender walked more meters in all categories.

Introducción: La obesidad mórbida se asocia a alteraciones de la capacidad de caminar, sin embargo se desconoce cómo es el comportamiento de la prueba de caminata de 6 minutos en sujetos con incrementos del índice de masa corporal (IMC). Objetivo: Describir el comportamiento de la prueba de caminata de 6 minutos en sujetos con IMC normal hasta la obesidad mórbida. Métodos: Mediante un diseño transversal analítico se estudiaron sujetos de ambos sexos de 18 a 60 años con IMC: normal (18.5-24.9 kg/m2), sobrepeso (25-29.9 kg/m2), obesidad (30-39.9 kg/m2), obesidad mórbida (> 40 kg/m2). Se les realizó prueba de caminata de 6 minutos, se acotaron variables demográficas y antecedentes personales patológicos. Se analizaron las categorías de IMC con ANOVA de una vía y ajuste de Bonferroni y los sexos con prueba t, ambos para grupos independientes y correlaciones de Pearson para las diversas variables. Una p < 0.05 fue considerada estadísticamente significativa. Resultados: Se estudiaron 480 sujetos de ambos sexos en cuatro grupos. Edad: hombres 43 ± 11 y mujeres 45 ± 10 años. Porcentaje diabetes mellitus (6.7%), hipertensión arterial (18.3%). Metros caminados hombres vs. mujeres por IMC (normal: 483 ± 56 vs. 449 ± 61; sobrepeso: 471 ± 55 vs. 441 ± 44; obesidad: 455 ± 70 vs. 421 ± 47; obesidad mórbida: 443 ± 49 vs. 403 ± 54; p < 0.05). Correlación IMC-metros caminados r: ­0.446 (p < 0.0001). Conclusiones: Los metros caminados en la prueba de caminata de 6 minutos disminuyeron conforme incrementó el IMC. El sexo masculino caminó más metros en todas las categorías.

[Variability of hemoglobin and hematocrit determined in blood gas equipment]. / Variabilidad de la hemoglobina y hematocrito determinados en equipo de gases sanguíneos.

Background: Usually hemoglobin and hematocrit are obtained from peripheral venous blood samples processed in equipment for hematic biometry. These parameters can also be determined from arterial samples processed on blood gas equipment. Its variability when using arterial samples and this equipment is unknown, in addition, if the lack of knowledge of this variability affects clinical decisions. Objective: To know the variability of hemoglobin and hematocrit from arterial blood samples processed in blood gas equipment. Material and methods: Analytic cross design. Consecutive subjects with stable cardiopulmonary disease were blindly studied. The samples were obtained at the same time for analysis in both equipments. Variability was analyzed with Bland-Altman descriptive statistic and its magnitude with the intraclass correlation coefficient. Results: Two hundred of blood samples from 50 patients were studied, 31 (62%) women, age 62 ± 14 years old, body mass index 30.11 ± 5.69 Kg/m2. The main comparison was peripheral venous blood sample processed in laboratory equipment (SYSMEX) vs. arterial sample on blood gas equipment (GEM). The mean difference (bias) and intraclass correlation coefficient for hemoglobin were: 0.12 (-1.45, 1.23) and 0.95 (0.91, 0.97); for the hematocrit -4.4 (-0.4, 8.54), and 0.72 (0.51, 0.84). Conclusions: The mean difference and bias for hemoglobin was close to 0; the hematocrit was higher. Hemoglobin from arterial samples processed in blood gas equipment can be used to make clinical decisions.

Introducción: usualmente, la hemoglobina y el hematocrito se obtienen de sangre venosa periférica procesada en equipo convencional para biometría hemática, también pueden ser determinados de muestras arteriales procesadas en equipos para gases sanguíneos. Se desconoce su variabilidad al utilizar muestras arteriales y equipos para gases sanguíneos, además, si esta variabilidad pudiera afectar las decisiones clínicas. Objetivo: conocer la variabilidad de la hemoglobina y hematocrito de muestras sanguíneas arteriales procesadas en equipo de gases sanguíneos. Material y métodos: diseño transversal analítico. Se estudiaron de forma ciega sujetos consecutivos con enfermedad cardiopulmonar estable. Las muestras sanguíneas se adquirieron al mismo tiempo para su análisis en ambos equipos. La variabilidad se analizó con el estadístico descriptivo de Bland-Altman y su magnitud con el coeficiente de correlación intraclase. Resultados: se analizaron 200 muestras sanguíneas de 50 pacientes, 31 (62%) mujeres, edad grupal 62 ± 14 años, índice de masa corporal 30.11 ± 5.69 Kg/m2. La principal comparación: muestra sanguínea venosa periférica procesada en equipo del laboratorio (SYSMEX) frente a muestra arterial en equipo de gases sanguíneos (GEM). La diferencia media (sesgo) y el coeficiente de correlación intraclase de la hemoglobina fueron: 0.12 (-1.45, 1.23) y 0.95 (0.91, 0.97); hematocrito -4.4 (-0.4, 8.54) y 0.72 (0.51, 0.84). Conclusiones: la diferencia media y sesgo de la hemoglobina fue cercana a 0; la del hematocrito fue mayor. La hemoglobina de muestras arteriales procesadas en equipos de gases sanguíneos son útiles para tomar decisiones clínicas.

[Within-subject variability of the 6-minute walk test]. / Variabilidad intrasujeto de la prueba de caminata de seis minutos.

Background: The 6-minute walk test assesses the ability to perform exercise and it is widely used, of low cost, and of diverse variability. Objective: To define the usefulness of a second 6-minute walk test performed 30 minutes from the first. Material and methods. Material and methods: An observational, longitudinal and analytical study was carried out in subjects born and inhabitants from Mexico City, both genders, without cardiopulmonary disease. Their demographic variables were recorded. Differences were calculated with the t test for independent groups and variability with the Bland-Altman statistic; its magnitude, with the intraclass correlation coefficient and 95% confidence intervals (95% CI). A p < 0.05 was considered significant. Results: 200 tests from 100 subjects were studied. Average age was 36 ± 11 years. Body mass index average was 24.71 ± 3.24 kg/m2. 43 subjects were male (43%). The most frequent activity was arts and crafts in 38 (38%). Only 55 subjects (55%) increased by 24 the number of meters walked in the second test. Total of meters walked on walk 1 vs. 2 were: 437.65 ± 48.84 vs. 441.62 ± 11.49. Mean difference (bias) was of -4 (57.9, -65.9) and intraclass correlation coefficient of 0.800 (95% CI, 0.717-0.861). Conclusions: The 6-minute walk test is reproducible with wide variability. These results suggest to do only one 6-minute walk test.

Introducción: la prueba de caminata de seis minutos evalúa la capacidad para hacer ejercicio y es de amplio uso, bajo costo y variabilidad diversa. Objetivo: definir la utilidad de una segunda prueba de caminata de seis minutos realizada a 30 minutos de la primera. Material y métodos: se llevó a cabo un estudio observacional, longitudinal y analítico de sujetos nacidos y habitantes de la Ciudad de México, de ambos géneros, sin enfermedad cardiopulmonar. Se registraron sus variables demográficas. Las diferencias se calcularon con la prueba t para grupos independientes y la variabilidad con el estadístico de Bland-Altman; su magnitud, con el coeficiente de correlación intraclase e intervalos de confianza del 95% (IC 95%). Una p < 0.05 se consideró significativa. Resultados: se estudiaron 200 pruebas de 100 sujetos. La edad promedio fue de 36 ± 11 años. La media del índice de masa corporal fue 24.71 ± 3.24 kg/m2. Fueron 43 hombres (43%). La actividad más frecuente fueron las artes y los oficios en 38 (38%). Solo en 55 (55%) incrementaron en 24 los metros caminados en la segunda prueba. Los metros caminados totales de la caminata 1 frente a la 2 fueron 437.65 ± 48.84 frente a 441.62 ± 11.49. La diferencia media (sesgo) fue de −4 (57.9, −65.9) y el coeficiente de correlación intraclase de 0.800 (IC 95% 0.717-0.861). Conclusiones: la prueba de caminata de seis minutos es reproducible con variabilidad amplia. Estos resultados sugieren realizar solo una prueba de caminata de seis minutos.

Variabilidad intrasujeto de la prueba de caminata de seis minutos / Within-subject variability of the 6-minute walk test

Introducción: la prueba de caminata de seis minutos evalúa la capacidad para hacer ejercicio y es de amplio uso, bajo costo y variabilidad diversa. Objetivo: definir la utilidad de una segunda prueba de caminata de seis minutos realizada a 30 minutos de la primera. Material y métodos: se llevó a cabo un estudio observacional, longitudinal y analítico de sujetos nacidos y habitantes de la Ciudad de México, de ambos géneros, sin enfermedad cardiopulmonar. Se registraron sus variables demográficas. Las diferencias se calcularon con la prueba t para grupos independientes y la variabilidad con el estadístico de BlandAltman; su magnitud, con el coeficiente de correlación intraclase e intervalos de confianza del 95% (IC 95%). Una p < 0.05 se consideró significativa. Resultados: se estudiaron 200 pruebas de 100 sujetos. La edad promedio fue de 36 ± 11 años. La media del índice de masa corporal fue 24.71 ± 3.24 kg/m2. Fueron 43 hombres (43%). La actividad más frecuente fueron las artes y los oficios en 38 (38%). Solo en 55 (55%) incrementaron en 24 los metros caminados en la segunda prueba. Los metros caminados totales de la caminata 1 frente a la 2 fueron 437.65 ± 48.84 frente a 441.62 ± 11.49. La diferencia media (sesgo) fue de −4 (57.9, −65.9) y el coeficiente de correlación intraclase de 0.800 (IC 95% 0.717-0.861). Conclusiones: la prueba de caminata de seis minutos es reproducible con variabilidad amplia. Estos resultados sugieren realizar solo una prueba de caminata de seis minutos

Background: The 6-minute walk test assesses the ability to perform exercise and it is widely used, of low cost, and of diverse variability. Objective: To define the usefulness of a second 6-minute walk test performed 30 minutes from the first. Material and methods: An observational, longitudinal and analytical study was carried out in subjects born and inhabitants from Mexico City, both genders, without cardiopulmonary disease. Their demographic variables were recorded. Differences were calculated with the t test for independent groups and variability with the Bland-Altman statistic; its magnitude, with the intraclass correlation coefficient and 95% confidence intervals (95% CI). A p < 0.05 was considered significant. Results: 200 tests from 100 subjects were studied. Average age was 36 ± 11 years. Body mass index average was 24.71 ± 3.24 kg/m2. 43 subjects were male (43%). The most frequent activity was arts and crafts in 38 (38%). Only 55 subjects (55%) increased by 24 the number of meters walked in the second test. Total of meters walked on walk 1 vs. 2 were: 437.65 ± 48.84 vs. 441.62 ± 11.49. Mean difference (bias) was of −4 (57.9, −65.9) and intraclass correlation coefficient of 0.800 (95% CI, 0.717-0.861). Conclusions: The 6-minute walk test is reproducible with wide variability. These results suggest to do only one 6-minute walk test

[Characterization of gas exchange parameters in Mexico City]. / Caracterización de parámetros del intercambio gaseoso en la Ciudad de México.

Background: At high altitude the gas exchange is impaired, in the moderate altitude of Mexico City they are not yet defined. Objective: To characterize the gas exchange in the moderate altitude of Mexico City. Material and methods: Through an analytical cross-sectional study, subjects born and inhabitants of Mexico City, both genders, aged 20 to 59 years without cardiopulmonary disease, were studied. Their demographic variables, simple spirometry and arterial blood gas were recorded. Differences in variables were calculated with one-way ANOVA for independent groups and Bonferroni adjustment. p < 0.05 was accepted as significant. Results: 335 subjects were studied, 168 (50.15%) men. Group age 45 ± 11 years old, body mass index 22.97 ± 1.54 Kg/m2. Forced expiratory volume ratio in the first second / Forced vital capacity (FEV1/FVC) 91.58 ± 12.86%. The arterial oxygen pressure was: 66 ± 5.02 mmHg, carbon dioxide: 32.07 ± 2.66 mmHg, arterial oxygen saturation: 93.0 3 ± 1.80%, and hemoglobin: 14.07 ± 1.52 gr/dL. Conclusions: The arterial oxygen pressure and carbon dioxide are lowered at the Mexico City altitude.

Introducción: en las grandes altitudes, el intercambio gaseoso suele estar deteriorado; en la altitud moderada de la Ciudad de México esto no está aún plenamente definido. Objetivo: caracterizar el intercambio gaseoso en la altitud moderada de la Ciudad de México. Material y métodos: mediante un estudio transversal analítico se estudiaron sujetos nacidos y habitantes de la Ciudad de México, de ambos géneros, con edades de 20 a 59 años sin enfermedad cardiopulmonar. Se registraron sus variables demográficas, espirometría simple y de gasometría arterial. Las diferencias en las variables se calcularon con ANOVA de una vía para grupos independientes y ajuste de Bonferroni. Una p < 0.05 se aceptó como significativa. Resultados: se estudiaron 335 sujetos, de los cuales 168 (50.15%) fueron hombres, la edad grupal fue de 45 ± 11 años, con índice de masa corporal 22.97 ± 1.54 Kg/m2. La relación volumen espiratorio forzado en el primer segundo/ Capacidad vital forzada (VEF1/CVF) de 91.58 ± 12.86%. La presión arterial de oxígeno fue de 66 ± 5.02 mmHg, el bióxido de carbono: 32.07 ± 2.66 mmHg, la saturación arterial de oxígeno: 93.03 ± 1.80% y la hemoglobina: 14.07 ± 1.52 gr/dL. Conclusiones: la presión arterial de oxígeno y del bióxido de carbono están disminuidos a la altura de la Ciudad de México.

Caracterización de parámetros del intercambio gaseoso en la Ciudad de México / Characterization of gas exchange parameters in Mexico City

Introducción: en las grandes altitudes, el intercambio gaseoso suele estar deteriorado; en la altitud moderada de la Ciudad de México esto no está aún plenamente definido. Objetivo: caracterizar el intercambio gaseoso en la altitud moderada de la Ciudad de México. Material y métodos: mediante un estudio transversal analítico se estudiaron sujetos nacidos y habitantes de la Ciudad de México, de ambos géneros, con edades de 20 a 59 años sin enfermedad cardiopulmonar. Se registraron sus variables demográficas, espirometría simple y de gasometría arterial. Las diferencias en las variables se calcularon con ANOVA de una vía para grupos independientes y ajuste de Bonferroni. Una p < 0.05 se aceptó como significativa. Resultados: se estudiaron 335 sujetos, de los cuales 168 (50.15%) fueron hombres, la edad grupal fue de 45 ± 11 años, con índice de masa corporal 22.97 ± 1.54 Kg/m2. La relación volumen espiratorio forzado en el primer segundo/Capacidad vital forzada (VEF1/CVF) de 91.58 ± 12.86%. La presión arterial de oxígeno fue de 66 ± 5.02 mmHg, el bióxido de carbono: 32.07 ± 2.66 mmHg, la saturación arterial de oxígeno: 93.03 ± 1.80% y la hemoglobina: 14.07 ± 1.52 gr/dL. Conclusiones: la presión arterial de oxígeno y del bióxido de carbono están disminuidos a la altura de la Ciudad de México.

Background: At high altitude the gas exchange is impaired, in the moderate altitude of Mexico City they are not yet defined. Objective: To characterize the gas exchange in the moderate altitude of Mexico City. Material and methods: Through an analytical cross-sectional study, subjects born and inhabitants of Mexico City, both genders, aged 20 to 59 years without cardiopulmonary disease, were studied. Their demographic variables, simple spirometry and arterial blood gas were recorded. Differences in variables were calculated with one-way ANOVA for independent groups and Bonferroni adjustment. p < 0.05 was accepted as significant. Results: 335 subjects were studied, 168 (50.15%) men. Group age 45 ± 11 years old, body mass index 22.97 ± 1.54 Kg/m2. Forced expiratory volume ratio in the first second / Forced vital capacity (FEV1/FVC) 91.58 ± 12.86%. The arterial oxygen pressure was: 66 ± 5.02 mmHg, carbon dioxide: 32.07 ± 2.66 mmHg, arterial oxygen saturation: 93.0 3 ± 1.80%, and hemoglobin: 14.07 ± 1.52 gr/dL. Conclusions: The arterial oxygen pressure and carbon dioxide are lowered at the Mexico City altitude.

[Deterioration of gas exchange in subjects with an increase in body mass index at an altitude of 2,240 meters above sea level]. / Deterioro del intercambio gaseoso en sujetos con incremento del índice de masa corporal a una altitud de 2,240 metros sobre el nivel del mar.

Introducción: Las alteraciones del intercambio gaseoso se han reconocido en la obesidad mórbida; sin embargo, no se conoce su comportamiento conforme se incrementa el índice de masa corporal. Objetivo: Conocer el comportamiento del intercambio gaseoso a la altura de la Ciudad de México en el desarrollo de obesidad mórbida. Métodos: Mediante un diseño transversal analítico se estudió a sujetos pareados por género y edad de cuatro grupos diferentes de índice de masa corporal (kg/m2): normal (18.5-24.9), sobrepeso (25-29.9), obesidad (30-39.9) y obesidad mórbida (≥ 40). Se obtuvieron sus antecedentes patológicos y demográficos, variables de gasometría arterial y espirometría simple. Las variables se determinaron de acuerdo con las características de la muestra; las diferencias entre grupos se realizaron mediante Anova de una vía con ajuste de Bonferroni, así como la correlación de Pearson para las variables relacionadas. Una p < 0.05 se consideró con significación estadística. Resultados: Se estudió a 560 pacientes en cuatro grupos. La edad promedio fue de 49 ± 11 años. La mayor frecuencia de diabetes mellitus (34.29%), hipertensión arterial (50%) e hiperlipidemia (36.43%) se registró en el grupo de obesidad, y la de roncador (73.57%) en la obesidad mórbida. Se identificaron diferencias desde el grupo normal respecto de la obesidad mórbida: PaCO2 31.37 ± 2.08 vs. 38.14 ± 5.10 mmHg; PaO2 68.28 ± 6.06 vs. 59.86 ± 9.28 mmHg y SaO2 93.51 ± 1.93 vs. 89.71 ± 5.37%, todas con p = 0.0001. Correlación IMC-PaCO2: 0.497, e IMC-PaO2: -0.365, p = 0.0001, respectivamente. Conclusiones: A la altitud de la Ciudad de México y con índice de masa corporal > 30 kg/m2, las variables relacionadas con el intercambio gaseoso y espirometría simple comienzan a deteriorarse; son evidentes con IMC > 40 kg/m2. Introduction: Alterations of gas exchange have been recognized in morbid obesity, however, it is not known how their behavior would be as the body mass index increases. Objective: To know the behavior of gas exchange at the level of Mexico City in the development of morbid obesity. Methods: Through analytical design, subjects matched by gender and age were studied from four different groups of body mass index (kg/m2), normal (18.5-24.9), overweight (25-29.9), obesity (30-39.9) and morbid obesity (≥ 40). Their pathological and demographic antecedents, arterial blood gas and simple spirometry variables were obtained. The variables were shown according to their sample characteristic. The differences between groups were made using one way Anova with Bonferroni adjustment, as well as Pearson's correlation for the related variables. Statistical significance was considered with p < 0.05. Results: 560 subjects were studied in 4 groups. The average age 49 ± 11 years old. The highest frequency of diabetes mellitus (34.29%), arterial hypertension (50%) and hiperlipidemia (36.43%) was in the obesity group, and being snoring (73.57%) in morbid obesity. There were differences from the normal group versus. morbid obesity: PaCO2 31.37 ± 2.08 versus. 38.14 ± 5.10 mmHg; PaO2 68.28 ± 6.06 versus. 59.86 ± 9.28 mmHg and SaO2 93.51 ± 1.93 versus. 89.71 ± 5.37%, all with p = 0.0001. The IMC-PaCO2 correlation: 0.497, and IMC-PaO2: −0.365, p = 0.0001 respectively. Conclusions: At the altitude of Mexico City and body mass index > 30 kg/m2 the variables related to gas exchange and simple spirometry begin to deteriorate; are evident with BMI > 40 kg/m2.

Deterioro del intercambio gaseoso en sujetos con incremento del índice de masa corporal a una altitud de 2, 240 metros sobre el nivel del mar / Deterioration of gas exchange in subjects with an increase in body mass index at an altitude of 2, 240 meters above sea level

Resumen Introducción: Las alteraciones del intercambio gaseoso se han reconocido en la obesidad mórbida; sin embargo, no se conoce su comportamiento conforme se incrementa el índice de masa corporal. Objetivo: Conocer el comportamiento del intercambio gaseoso a la altura de la Ciudad de México en el desarrollo de obesidad mórbida. Métodos: Mediante un diseño transversal analítico se estudió a sujetos pareados por género y edad de cuatro grupos diferentes de índice de masa corporal (kg/m2): normal (18.5-24.9), sobrepeso (25-29.9), obesidad (30-39.9) y obesidad mórbida (≥ 40). Se obtuvieron sus antecedentes patológicos y demográficos, variables de gasometría arterial y espirometría simple. Las variables se determinaron de acuerdo con las características de la muestra; las diferencias entre grupos se realizaron mediante Anova de una vía con ajuste de Bonferroni, así como la correlación de Pearson para las variables relacionadas. Una p < 0.05 se consideró con significación estadística. Resultados: Se estudió a 560 pacientes en cuatro grupos. La edad promedio fue de 49 ± 11 años. La mayor frecuencia de diabetes mellitus (34.29%), hipertensión arterial (50%) e hiperlipidemia (36.43%) se registró en el grupo de obesidad, y la de roncador (73.57%) en la obesidad mórbida. Se identificaron diferencias desde el grupo normal respecto de la obesidad mórbida: PaCO2 31.37 ± 2.08 vs. 38.14 ± 5.10 mmHg; PaO2 68.28 ± 6.06 vs. 59.86 ± 9.28 mmHg y SaO2 93.51 ± 1.93 vs. 89.71 ± 5.37%, todas con p = 0.0001. Correlación IMC-PaCO2: 0.497, e IMC-PaO2: -0.365, p = 0.0001, respectivamente. Conclusiones: A la altitud de la Ciudad de México y con índice de masa corporal > 30 kg/m2, las variables relacionadas con el intercambio gaseoso y espirometría simple comienzan a deteriorarse; son evidentes con IMC > 40 kg/m2.

Abstract Introduction: Alterations of gas exchange have been recognized in morbid obesity, however, it is not known how their behavior would be as the body mass index increases. Objective: To know the behavior of gas exchange at the level of Mexico City in the development of morbid obesity. Methods: Through analytical design, subjects matched by gender and age were studied from four different groups of body mass index (kg/m2), normal (18.5-24.9), overweight (25-29.9), obesity (30-39.9) and morbid obesity (≥ 40). Their pathological and demographic antecedents, arterial blood gas and simple spirometry variables were obtained. The variables were shown according to their sample characteristic. The differences between groups were made using one way Anova with Bonferroni adjustment, as well as Pearson’s correlation for the related variables. Statistical significance was considered with p < 0.05. Results: 560 subjects were studied in 4 groups. The average age 49 ± 11 years old. The highest frequency of diabetes mellitus (34.29%), arterial hypertension (50%) and hiperlipidemia (36.43%) was in the obesity group, and being snoring (73.57%) in morbid obesity. There were differences from the normal group versus. morbid obesity: PaCO2 31.37 ± 2.08 versus. 38.14 ± 5.10 mmHg; PaO2 68.28 ± 6.06 versus. 59.86 ± 9.28 mmHg and SaO2 93.51 ± 1.93 versus. 89.71 ± 5.37%, all with p = 0.0001. The IMC-PaCO2 correlation: 0.497, and IMC-PaO2: −0.365, p = 0.0001 respectively. Conclusions: At the altitude of Mexico City and body mass index > 30 kg/m2 the variables related to gas exchange and simple spirometry begin to deteriorate; are evident with BMI > 40 kg/m2.

Disentangling the environmental processes responsible for the world's largest farmed fish-killing harmful algal bloom: Chile, 2016.

The dictyochophyte microalga Pseudochattonella verruculosa was responsible for the largest farmed fish mortality ever recorded in the world, with losses for the Chilean salmon industry amounting to US$ 800 M in austral summer 2016. Super-scale climatic anomalies resulted in strong vertical water column stratification that stimulated development of a dynamic P. verruculosa thin layer (up to 38 µg chl a L-1) for several weeks in Reloncaví Sound. Hydrodynamic modeling (MIKE 3D) indicated that the Sound had extremely low flushing rates (between 121 and 200 days) in summer 2016. Reported algal cell densities of 7000-20,000 cells mL-1 generated respiratory distress in fish that was unlikely due to low dissolved oxygen (permanently >4 mg L-1). Histological examination of salmon showed that gills were the most affected organ with significant tissue damage and circulatory disorders. It is possible that some of this damage was due to a diatom bloom that preceded the Pseudochattonella event, thereby rendering the fish more susceptible to Pseudochattonella. No correlation between magnitude of fish mortality and algal cell abundance nor fish age was evident. Algal cultures revealed rapid growth rates and high cell densities (up to 600,000 cells mL-1), as well as highly complex life cycle stages that can be easily overlooked in monitoring programs. In cell-based bioassays, Chilean P. verruculosa was only toxic to the RTgill-W1 cell line following exposures to high cell densities of lysed cells (>100,000 cells mL-1). Fatty acid profiles of a cultured strain showed elevated concentrations of potentially ichthyotoxic, long-chain polyunsaturated fatty acids (PUFAs) (69.7% ± 1.8%)- stearidonic (SDA, 18:4ω3-28.9%), and docosahexaenoic acid (DHA, 22:6ω3-22.3%), suggesting that lipid peroxidation may help to explain the mortalities, though superoxide production by Pseudochattonella was low (< 0.21 ± 0.19 pmol O2- cell-1 h-1). It therefore remains unknown what the mechanisms of salmon mortality were during the Pseudochattonella bloom. Multiple mitigation strategies were used by salmon farmers during the event, with only delayed seeding of juvenile fish into the cages and towing of cages to sanctuary sites being effective. Airlift pumping, used effectively against other fish-killing HABs in the US and Canada was not effective, perhaps because it brought subsurface layers of Pseudochattonella to the surface, or and it also may have lysed the fragile cells, rendering them more lethal. The present study highlights knowledge gaps and inefficiency of contingency plans by the fish farming industry to overcome future fish-killing algal blooms under future climate change scenarios. The use of new technologies based on molecular methods for species detection, good farm practices by fish farms, and possible mitigation strategies are discussed.

Unraveling the Karenia selliformis complex with the description of a non-gymnodimine producing Patagonian phylotype.

Karenia selliformis is a bloom-forming toxic dinoflagellate known for production of gymnodimines (GYMs) and causing mass mortalities of marine fauna. Blooms have been reported from coastal waters of New Zealand, Mexico, Tunisia, Kuwait, Iran, China and Chile. Based on molecular phylogeny, morphology, toxin production, pigment composition and cell growth of Chilean K. selliformis isolated in 2018 (CREAN_KS01 and CREAN_KS02), this study revealed a more complex diversity within this species than previously thought. A phylogenetic reconstruction based on the large sub-unit ribosomal nucleotide (LSU rDNA) and Internal Transcriber Spacer (ITS) sequences of 12 worldwide isolates showed that within the K. selliformis clade there are at least two different phylotypes with clear phenotypic differences. Morphological differences related to the dorsal-ventral compression, shape of the hyposome and the presence of pores on the left lobe of the hyposome. A comparison of pigment signatures among worldwide isolates revealed the existence of both acyl-oxyfucoxanthin and fucoxanthin-rich strains within the phylotypes. A LC-MS/MS screening on both Chilean 2018 K. selliformis strains showed for first time no GYMs production among cultured clones of this species. However, both CREAN_KS01 and CREAN_KS02 contained two compounds with the same mass transition as brevenal, a brevetoxin related compound. A fish gill cell-based assay showed that the CREAN_KS02 strain was highly cytotoxic but pure GYM standard did not exhibit loss of cell viability, even at cell concentrations equivalent or exceeding those reported in nature. The fatty acid profile of CREAN_KS02 included high levels of saturated (14:0; 16:0) and polyunsaturated (18:3ω6+18:5ω3; 22:6ω3) fatty acids but superoxide production in this strain was low (0.86±0.53 pmol O2- cell-1 h-1). A factorial T-S growth experiment using the CREAN_KS02 strain showed a µmax of 0.41±0.03 d-1 at high salinity and temperature, which points to its optimal environmental niche in offshore waters during the summer season. In conclusion, the present study provides evidence for significant genetic and phenotypic variability among worldwide isolates, which points to the existence of a K. selliformis "species complex". The massive fauna mortality during K. selliformis bloom events in the Chilean coast cannot be explained by GYMs nor brevetoxins, but can to a large extent be accounted for by the high production of long-chain PUFAs and/or still uncharacterized highly toxic compounds.

The Molecular Cloud Lifecycle.

Giant molecular clouds (GMCs) and their stellar offspring are the building blocks of galaxies. The physical characteristics of GMCs and their evolution are tightly connected to galaxy evolution. The macroscopic properties of the interstellar medium propagate into the properties of GMCs condensing out of it, with correlations between e.g. the galactic and GMC scale gas pressures, surface densities and volume densities. That way, the galactic environment sets the initial conditions for star formation within GMCs. After the onset of massive star formation, stellar feedback from e.g. photoionisation, stellar winds, and supernovae eventually contributes to dispersing the parent cloud, depositing energy, momentum and metals into the surrounding medium, thereby changing the properties of galaxies. This cycling of matter between gas and stars, governed by star formation and feedback, is therefore a major driver of galaxy evolution. Much of the recent debate has focused on the durations of the various evolutionary phases that constitute this cycle in galaxies, and what these can teach us about the physical mechanisms driving the cycle. We review results from observational, theoretical, and numerical work to build a dynamical picture of the evolutionary lifecycle of GMC evolution, star formation, and feedback in galaxies.

Differences in partial oxygen saturation obtained from three pulse oximeters.

INTRODUCCIÓN: Se estima que existe variabilidad en la medición de la saturación parcial de oxígeno entre distintos oxímetros de pulso. OBJETIVO: Conocer la variabilidad de la medición de acuerdo con el oxímetro de pulso utilizado en la práctica clínica. MATERIAL Y MÉTODOS: Diseño transversal, sujetos consecutivos. Se obtuvieron variables demográficas, ocupación y enfermedad. Se estimaron las diferencias en la variabilidad de tres oxímetros de pulso. Las variables nominales se informaron con frecuencias y porcentajes; las numéricas, con promedios y desviación estándar. La variabilidad se calculó con el estadístico de Bland-Altman y su magnitud con el coeficiente de correlación intraclase (intervalo de confianza del 95%). RESULTADOS: Se estudiaron 255 pacientes con una edad promedio de 61 ± 15 años y un índice de masa corporal de 30.28 ± 6.59 kg/m2, de los cuales 145 (56.8%) fueron mujeres y 136 (53.33%) tuvieron hábito tabáquico. La ocupación y la enfermedad con mayor frecuencia fueron obrero (98; 38.43%) y enfermedad pulmonar obstructiva crónica (143; 56.08%). El promedio grupal de saturación arterial de oxígeno frente a saturación parcial de oxígeno fue de 91.28 ± 4.07% frente a 90.64 ± 3.89% (p < 0.0001). La diferencia media (límites de acuerdo) y el coeficiente de correlación intraclase (intervalo de confianza del 95%) fueron, respectivamente, para los tres oxímetros: Onyx II -0.5 (3.4, -4.3) y 0.949 (0.935, 0.960), Hergom 0.2 (3.4, -2.9) y 0.951 (0.937, 0.962), y Rossmax SB220 -1.6 (36.2, -39.5) y 0.784 (0.724, 0.831). CONCLUSIONES: Los oxímetros de pulso Onyx II y Hergom tuvieron menor variabilidad, mientras que el Rossmax SB220 la tuvo muy amplia, por lo que no resulta aconsejable para uso clínico. BACKGROUND: It may be estimated certain variability in the measurement of partial oxygen saturation between pulse oximeters. OBJECTIVE: Describe the variability of partial oxygen saturation obtained from three different pulse oximeters. MATERIAL AND METHODS: Cross design, consecutive subjects. Data related to demographic variables, occupation, diseases and differences in variability of three pulse oximeters was obtained. Nominal variables were reported with frequencies and percentages, numerical with averages and standard deviation; the variability was calculated with the Bland-Altman statistic and its magnitude with the intraclass correlation coefficient (95% confidence interval). RESULTS: The 255 patients studied were aged between 61 ± 15 years, body mass index ranked 30.28 ± 6.59 kg/m2, 145 (56.8%) were female and 136 (53.33%) had tobacco smoking habit. The most frequent occupation were worker (98; 38.43%), and disease chronic obstructive pulmonary disease (143; 56.08%). Group average of arterial oxygen saturation vs. partial oxygen saturation: 91.28 ± 4.07% vs. 90.64 ± 3.89% (p < 0.0001). For the three oxymeters, the mean difference (limits of agreement) and the intraclass correlation coefficient (95% confidence interval) were respectively: Onyx-II −0.5 (3.4, −4.3), 0.949 (0.935, 0.960), Hergom 0.2 (3.4, −2.9), 0.951 (0.937, 0.962) and Rossmax SB220 −1.6 (36.2, −39.5), 0.784 (0.724, 0.831). CONCLUSIONS: Onyx II and Hergom pulse oximeters had low variability, while SB220 showed ample variability and it is therefore, not advisable to use in clinical practice.

Variability of arterial and peripheral venous blood gases parameters in subjects with stable obstructive pulmonary disease / Variabilidad de los parámetros de la gasometría arterial y venosa periférica en sujetos con enfermedad pulmonar obstructiva crónica en condición estable

Background: Peripheral venous blood gases may be useful in subjects with exacerbation of chronic obstructive pulmonary disease to evaluate their gas exchange. Objective: To describe the variability of parameters of arterial and peripheral venous blood gases in subjects with stable obstructive pulmonary disease. Methods: Cross-sectional design, consecutive subjects were studied in a blinded manner, while arterial and peripheral venous blood was obtained for analysis. Variability was established with Bland-Altman statistical method and its magnitude with the intraclass correlation coefficient (95 % confidence interval). Results: Three hundred blood samples from 150 patients were studied, 89 (59.3%) women, age 66 ± 10 years old, body mass index 28.44 ± 4.81 Kg/m2. Mean difference (bias) [intraclass correlation coeficient] pH 0.012 (-0.009, 0.032) [0.927], Carbon dioxide pressure -6.5 (-14.1, 1.1) [ 0.643], serum bicarbonate -1.3 (-3.3, 0.7) [0.929], base excess -1 (-4, 2.1) [0.904], hemoglobin -0.1 (-1.9, 1.8) [0.947]. Conclusions: The variability of pH, serum bicarbonate, and hemoglobin are similar in both blood samples. These arterial or peripheral venous blood gas parameters could be used interchangeably.

Introducción: la gasometría venosa periférica puede ser de utilidad en sujetos con exacerbación de la enfermedad pulmonar obstructiva crónica para evaluar su intercambio gaseoso. Objetivo: describir la variabilidad de los parámetros de la gasometría arterial y venosa periférica en sujetos con enfermedad pulmonar obstructiva crónica en condición estable. Métodos: diseño transversal, se estudiaron sujetos consecutivos de forma cegada, al mismo tiempo se obtuvo sangre arterial y venosa periférica para su análisis. La variabilidad se determinó con el método estadístico de Bland-Altman y su magnitud con el coeficiente de correlación intraclase (intervalo de confianza al 95%). Resultados: se estudiaron 300 muestras sanguíneas de 150 pacientes, 89 mujeres (59.3%), edad del grupo 66 ± 10 años, el índice de masa corporal 28.44 ± 4.81 Kg/m2. La diferencia media (sesgo) [coeficiente de correlación intraclase] para el pH: 0.012 (-0.009, 0.032) [0.927], presión de bióxido de carbono: -6.5 (-14.1, 1.1) [ 0.643], bicarbonato sérico: -1.3 (-3.3, 0.7) [0.929], y exceso de base: -1 (-4, 2.1) [0.904], hemoglobina: -0.1 (-1.9, 1.8) [0.947]. Conclusiones: la variabilidad del pH, el bicarbonato sérico y la hemoglobina son similares en ambas muestras sanguíneas. Estos parámetros de la gasometría arterial o venosa periférica podrían ser utilizados en forma intercambiable.

Influence of age at first calving in a continuous calving season on productive, functional, and economic performance in a Blonde d'Aquitaine beef population.

The lifetime production of 7,655 cows with known age at first calving and a total of 27,118 parity records from 301 purebred Blonde d'Aquitaine herds were used to demonstrate the economic benefits of 2 yr of age at first calving. Ages at first calving ranged from 20 to 48 mo, and cows were divided into 5 calving groups, starting with early calving from age 20 to 27 mo up to late calving from age 40 to 48 mo. The information was gathered into 2 data sets, one for only primiparous cows and the second for all cows. The traits analyzed in this study were grouped as functional, linear type, and production traits. Functional traits were calving interval, calving ease, and number of calvings. Skeletal, muscle, and functional appraisal were included as linear type traits. The production traits studied were BW and weaning weight, carcass growth, and conformation of the offspring. The only significant traits found in primiparous cows were late age at first calving, which resulted in heavier BW calves, and early age at first calving, which resulted in calves with greater carcass conformation scores. Age at first calving was found to be significant only in its effect on BW and the number of calvings over a cow's lifetime, with lighter calves for early age at first calving. Heritability for age at first calving was 0.17. Genetic correlation of age at first calving with direct calving ease was positive (0.27) and that with maternal calving ease was negative (-0.39). Age at first calving showed a negative genetic correlation with lifetime number of calvings (-0.29) and a positive correlation with calving interval (0.14). Correlations with production and type traits were low, except for skeletal development (-0.29). Based on phenotypic and genetic analysis, there is a tendency for early-calving cows to produce a greater lifetime number of calves with less muscle but good carcass growth. Age at first calving affected the number of heifers in the herd, replacement rate, and number of animals slaughtered each year. Shortening the age at first calving from 3 to 2 yr led to a reduction of heifer feeding cost of US$21.24 (17.7€), a reduction of production cost of $26.52 (22.1€), and a profit increase of $25.80 (21.50€) per slaughtered animal per year over lifetime cow production.

Expected consequences of including methane footprint into the breeding goals in beef cattle. A Spanish Blonde d'Aquitaine population as a case of study.

This study evaluates two potential scenarios for including methane (CH4 ) emissions in the breeding objectives of beef cattle, using the Spanish population of Blonde d'Aquitaine as a case of study. First, CH4 emissions were included as a cost using a shadow carbon price of 1.22€/CH4 kg (0.044€/CO2 kg) (carbon tax scenario). In the other scenario, a CH4 quota was applied, optimizing emissions per unit of product. The current production system was used as benchmark scenario (Scenario 1). The economic value of CH4 was calculated under all scenarios using a bioeconomic model that translated the production system into a mathematical function. Then, CH4 emissions were included with proper relative weight in the selection index under each scenario. The economic value of CH4 production from cows was -0.54€/year and -0.16€/year in a carbon tax and in a CH4 quota scenario, respectively. Economic values for CH4 production from fattening calves were -1.22€/year and -0.34€/year in a carbon tax and a quota scenario, respectively. The relative weights of total CH4 traits in the indices were 4.9% and 1.8% in a carbon tax and quota scenario. The carbon tax scenario led to smaller cows (-7.59 kg of mature weight) and a decrease in carcass weight gain of calves (-4.78 g/day) involving a reduction in emissions in comparison with Scenario 1 (-0.76 CH4 kg/slaughtered calf/year). However, it also led to a lower expected gain in profit per unit of product (-7.86 €/slaughtered calf/year). A carbon quota scenario would select slightly smaller cows (-0.48 kg) with similar responses in maternal abilities (age at first calving, calving interval, maternal weaning weight, and calving ease) and growth, and lower emissions (-0.22 CH4 kg/slaughtered calf/year) regarding the benchmark scenario. Profit per cow would increase by +1.52€/slaughtered calf/year although this scenario implies a reduction in the number of cows per herd. In a carbon tax scenario, higher reduction in emissions implied a reduction of profitability per animal.