Seeing pain and pleasure on self and others: behavioural and psychophysiological reactivity in immersive virtual reality

Studies have explored behavioral and neural responses to the observation of pain in others. However, much less is known about how taking a physical perspective influences reactivity to the observation of others' pain and pleasure. To explore this issue we devised a novel paradigm in which 24 healthy participants immersed in a virtual reality scenario observed a virtual: needle penetrating (pain), caress (pleasure), or ball touching (neutral) the hand of an avatar seen from a first (1PP)- or a third (3PP)-person perspective. Subjective ratings and physiological responses [skin conductance responses (SCR) and heart rate (HR)] were collected in each trial. All participants reported strong feelings of ownership of the virtual hand only in 1PP. Subjective measures also showed that pain and pleasure were experienced as more salient than neutral. SCR analysis demonstrated higher reactivity in 1PP than in 3PP. Importantly, vicarious pain induced stronger responses with respect to the other conditions in both perspectives. HR analysis revealed equally lower activity during pain and pleasure with respect to neutral. SCR may reflect egocentric perspective, and HR may merely index general arousal. The results suggest that behavioral and physiological indexes of reactivity to seeing others' pain and pleasure were qualitatively similar in 1PP and 3PP. Our paradigm indicates that virtual reality can be used to study vicarious sensation of pain and pleasure without actually delivering any stimulus to participants' real body and to explore behavioral and physiological reactivity when they observe pain and pleasure from ego- and allocentric perspectives

Eficiencia en el uso del nitrógeno en vacas lecheras y su impacto en el ambiente

Tesis para obtener el grado de Doctora en Ciencia Animal, de la Universidad Nacional del Centro de la Provincia de Buenos Aires, en 2020El productor agropecuario se enfrenta al desafío de mejorar la eficiencia de uso de los recursos disponibles y, al mismo tiempo, reducir la contaminación ambiental. La producción animal representa una fuente significativa de gases de efecto invernadero (GEI) a través de la emisión de metano (CH4) y óxido nitroso (N2O), además de la contaminación del agua con nitratos (NO3-) y la volatilización de amoníaco (NH3). La optimización de la nutrición del ganado lechero es una herramienta clave para la problemática ambiental provocada por la acumulación de nitrógeno (N) y la emisión de CH4 en los sistemas lecheros. A pesar de la importancia que tiene en nuestro país la producción lechera, hasta el presente existe poca información sobre emisiones de CH4 y sobre la relación entre la eficiencia de utilización del N de la dieta (EUN) y las emisiones de CH4 en vacas lecheras. En este contexto, la presente tesis doctoral tiene como objetivo estudiar el efecto de distintos niveles de proteína bruta (PB) de la dieta sobre la productividad animal, la fermentación ruminal, el destino del N consumido y el impacto ambiental de vacas Holando Argentino en lactancia. En el capítulo 2, como parte de la revisión bibliográfica del tema, se realizó la evaluación de la situación actual con respecto a los niveles de PB utilizados y recomendados a nivel nacional e internacional, y la EUN. Para ello, se estudió la variabilidad de los niveles de PB en las dietas utilizadas en vacas en ordeño a nivel nacional, la secreción de N en leche, su relación con la EUN de la dieta, y las emisiones de CH4 entérico en 122 sistemas lecheros de las principales cuencas lecheras del país. Los valores de PB en los sistemas de Argentina observados fueron altos con respecto a las recomendaciones internacionales. Las EUN observadas fueron menores a las deseadas, demostrando que aún quedan muchas estrategias para mejorar este indicador. A continuación, en el capítulo 3, se realizó una revisión sistemática y un análisis global de las relaciones entre las variables en los resultados de 53 ensayos de alimentación publicados que tuvieron como objetivo evaluar diferentes concentraciones de PB en la dieta de vacas lecheras. Se realizó un análisis de componentes principales para evaluar las relaciones de las variables bajo estudio, y posteriormente, a fin de determinar la función que relaciona la concentración de PB (%) y variables productivas, se realizó un análisis a través de regresiones aleatorias. La revisión sistemática permitió generar una síntesis de la evidencia disponible para proseguir con el análisis en profundidad de las relaciones entre las variables. Si bien en algunas variables, como el consumo de materia seca (CMS), el contenido de proteína en leche y el N ureico en leche (NUL) tuvieron poca variabilidad de respuesta, la producción de leche individual y la EUN tuvieron una respuesta variable, siendo ambas variables de importancia para el costo de la dieta y el resultado económico final. La alta correlación negativa entre la concentración de NUL y la EUN demostró su utilidad como indicador de la eficiencia de utilización del N. En el capítulo 4, con el objetivo de evaluar la EUN de la dieta, la emisión de CH4 entérico, la producción de leche (PL) y el resultado económico, se llevó a cabo un ensayo a campo en vacas Holando Argentino en lactancia alimentadas con dietas con distinto contenido de PB; 13, 16 y 19 % PB. Con CMS y materia orgánica (MO) digestible similares, al aumentar el contenido de PB en la dieta) aumentó de forma lineal la PL (+ 16 %), el contenido y la excreción de proteína en leche (PBL). La excreción de N en leche (NL) mostró la misma tendencia que la PBL. Con respecto a la EUN, cuanto mayor fue el consumo de N (CN), menor fue la EUN. El volumen de orina, el N excretado en orina (NOr), y el N en forma de urea en orina (NUOr), al igual que la proporción de CN excretado en orina en forma de NOr y NUOr, aumentaron significativamente en respuesta al contenido de PB. La emisión diaria de CH4 entérico, la intensidad de emisión y la tasa de conversión de CH4 (Ym) no se vieron afectadas por el nivel de PB de la dieta. Con respecto a los indicadores económicos, el costo de la ración fue mayor a medida que aumentó el porcentaje de PB de la dieta. Sin embargo, al aumentar la PB de la dieta aumentó la PL, lo que permitió un mayor rendimiento de leche libre de ración, un mayor ingreso por vaca, y un mayor margen bruto. No obstante, los costos potenciales debido a una mayor excreción de N, y por lo tanto un mayor riesgo de lixiviación de NO3- y de emisión de N2O, fueron mayores a medida que se incrementó en contenido de PB. Estos resultados muestran que la optimización del contenido de PB en la dieta deberá ser un balance entre los impactos económicos y ambientales en la PL, ya que el consumo excesivo de N implicaría una mayor pérdida en forma de urea a través de la orina, lo que llevaría a un aumento de las emisiones de NH3 y N2O. Por último, en el capítulo 5, se llevó a cabo un ensayo en un sistema in vitro de doble flujo continuo con el objetivo de evaluar los efectos del aumento de los niveles de PB dieta utilizadas en ganado lechero sobre la fermentación ruminal, el metabolismo ruminal del N, la eficiencia de síntesis microbiana, la población microbiana y la producción de CH4 y. El aumento de la PB en la dieta (13, 16 y 19 % PB) no tuvo un efecto significativo en la digestibilidad in vitro de la MS, la MO o de la fibra. A medida que el contenido de PB aumentó, el pH ruminal medio aumentó linealmente, al igual que el pH máximo y mínimo. Las concentraciones de ácidos grasos volátiles totales (AGVT) y proporciones molares de acetato (C2), butirato (C4) y valerato (C5) no se vieron afectadas por los tratamientos, existiendo una tendencia a disminuir los AGVT de forma lineal a medida que aumenta el nivel de PB. Para el caso del propionato (C3), al igual que el iso-valerato y contrariamente al iso-butirato, si bien no hubo diferencias entre tratamientos, se observó una disminución en la proporción molar con el aumento en el contenido de PB de la dieta. La relación C2:C3 aumentó linealmente con el contenido de PB en la dieta. La emisión de CH4, y la densidad de la población de bacterias totales y metanogénicas no difirieron entre tratamientos. En lo que respecta al metabolismo del N, la concentración ruminal de N-NH3 en el efluente (mg/dL), así como el flujo de N total y N-NH3 (g/d), aumentaron linealmente al aumentar el contenido proteico de la dieta. Por el contrario, el flujo de N no amoniacal y de N bacteriano disminuyeron linealmente con el aumento de la PB de la dieta, siendo este último 32% menor en el tratamiento con mayor respecto al de menor contenido de PB. La digestibilidad de la proteína y la eficiencia de síntesis bacteriana (g N/kg MO), no se vieron afectadas por el contenido proteico en la dieta, observándose una tendencia a una disminución lineal a medida que el contenido de PB fue mayor. Dietas con niveles decrecientes de PB dieron como resultado patrones alterados de fermentación ruminal, como el pH ruminal y los cambios en el metabolismo de parte de los AGV y el N. Las dietas con 13% y 16% de PB proporcionaron efectos positivos sobre el flujo de N microbiano y una tendencia hacia una mejor eficiencia microbiana en el rumen; por lo tanto, fueron la mejor estrategia para una mejorar la utilización de N en el rumen. Más allá de ese nivel, no hubo más beneficios de alimentar una mayor PB en la dieta.Farmers are facing new challenges, having to improve the efficiency of use of available resources, and at the same time adapt to the demands in order to reduce environmental pollution. Animal production represents a significant source of GHG through methane (CH4) and nitrous oxide (N2O) emission, in addition to nitrates (NO3-) water pollution and ammonia (NH3) volatilization. The dairy cattle nutrition is a key tool for environmental problems caused by nitrogen (N) accumulation and CH4 emission in dairy systems. Despite the importance of milk production in our country, there is little information on CH4 emissions and its relationship with dietary N use efficiency (NUE) in dairy cows. In this context, the objective of this doctoral thesis was to study the effect of different dietary crude protein (CP) levels on productivity, ruminal fermentation, N intake fate and the environmental impact in Argentine Holstein dairy cows. As part of the literature review, in chapter 2, an evaluation of the CP levels currently used and the NUE values in Argentinian dairy systems was carried out. The dietary CP levels variability used in dairy cows, milk N secretion, its relationship with the NUE and enteric CH4 emissions of 122 national dairy systems located in main dairy basins of the country were studied. CP levels in Argentina's systems were high compared to international recommendations. Also, NUE values were lower than desired, demonstrating that there are still many strategies to improve this indicator. Furthermore, in chapter 3, a systematic review of 53 published feeding trials that evaluated different dietary CP in dairy cows, and global analysis of the relationships between under study variables, was carried out. For that purpose, a main components analysis of was done, and later, through random regressions, the function that relates the CP levels (%) and productive variables were determined. The systematic review allowed a synthesis of the available evidence to continue with the in-depth analysis of the relationships between variables. Although in some variables, such as dry matter intake (DMI), milk protein content and milk urea N (MUN) had low response variability, individual milk production and NUE had a variable response, being both variables of importance for the diet cost and the economic result. The high negative correlation between MUN concentration and NUE demonstrated MUN usefulness as a NUE indicator. In order to evaluate dietary NUE, enteric CH4 emission, milk production and economic results on Argentine Holstein dairy cows fed diets with different CP levels (13, 16 and 19 %) in chapter 4, a field trial was carried out. With similar DMI and organic matter (OM) digestibility, an increase in dietary CP content allowed a linear increase of milk production (+ 16 %), milk protein content and yield. Milk N excretion (MN) showed the same trend as milk protein yield. In addition, a higher N intake (NI) generated lower EUN. Urine volume, N excreted in urine (NU), and urea N in urine (UNU), as well as the proportion of NI excreted in urine, increased significantly in response to dietary CP level. Daily enteric CH4 emission, emission intensity and CH4 conversion rate (Ym) were not affected by dietary CP content. Respect to the economic indicators, the ration cost was higher as the percentage of dietary CP increased. However, as CP level increased, the milk production increased and allowed a higher milk yield free of ration cost, a higher income per cow, and a higher gross income. However, the potential costs due to increased excretion of N to the environment, and therefore increased risk of NO3- leaching and N2O emission, were higher as dietary CP content increased. These results show that optimizing CP content should be a balance between economic and environmental impacts on milk production, since excessive N intake would imply greater loss in the form of urea through the urine. Finally, a dual-flow continuous culture fermenter system was used to assess the effect of increased dietary CP levels used in dairy cattle on ruminal fermentation, N metabolism, microbial synthesis efficiency, microbial population and CH4 production (chapter 5). The increase of dietary CP content (13, 16 and 19 % PB) didn´t have a significant effect on the in vitro DM, OM of fiber digestibility. As dietary CP content increased, the mean, maximum and minimum ruminal pH increased linearly. The total volatile fatty acids (TVFA) concentration and molar proportions of acetate (C2), butyrate (C4) and valerate (C5) were not affected by treatments, with a tendency to decrease linearly the concentration of TVFA as dietary CP level increases. In the case of propionate (C3) and iso-valerate, although there were no differences between treatments, there was a decrease in the molar ratio with an increase in dietary CP content. The relationship C2:C3 increased linearly as the CP concentration was higher. CH4 production, total bacteria and methanogenic bacteria population density were similar between treatments. Respect to N metabolism, ruminal NH3-N effluent concentration (mg/dL), as well as total N (TN) and NH3-N (g/d) flow, increased linearly as CP content increased. In contrast, non NH3-N flow (NAN) and bacterial N decreased linearly with increasing content of CP, being 32% lower in high CP diet respect to the lower CP content diet. The protein digestibility and bacterial synthesis efficiency (g N/kg OM) were not affected by treatments, with a tendency of a linear decrease as dietary CP content increased. Diets with decreasing dietary CP levels resulted in altered patterns of ruminal fermentation, such as ruminal pH and changes in VFA and N metabolism. Diets with 13 and 16 CP % had positive effects on bacterial N flow and a tendency for improved efficiency of bacterial N synthesis. Therefore, both treatments were the best strategy for improving ruminal NUE. Beyond 16 CP %, there was no further benefit of feeding a higher dietary CP level.EEA RafaelaFil: Tieri, Maria Paz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina

Body visual discontinuity affects feeling of ownership and skin conductance responses

When we look at our hands we are immediately aware that they belong to us and we rarely doubt about the integrity, continuity and sense of ownership of our bodies. Here we explored whether the mere manipulation of the visual appearance of a virtual limb could influence the subjective feeling of ownership and the physiological responses (Skin Conductance Responses, SCRs) associated to a threatening stimulus approaching the virtual hand. Participants observed in first person perspective a virtual body having the right hand-forearm (i) connected by a normal wrist (Full-Limb) or a thin rigid wire connection (Wire) or (ii) disconnected because of a missing wrist (m-Wrist) or a missing wrist plus a plexiglass panel positioned between the hand and the forearm (Plexiglass). While the analysis of subjective ratings revealed that only the observation of natural full connected virtual limb elicited high levels of ownership, high amplitudes of SCRs were found also during observation of the non-natural, rigid wire connection condition. This result suggests that the conscious embodiment of an artificial limb requires a natural looking visual body appearance while implicit reactivity to threat may require physical body continuity, even non-naturally looking, that allows the implementation of protective reactions to threat

Heterosexual, gay, and lesbian people’s reactivity to virtual caresses on their embodied avatars’ taboo zones

Embodying an artificial agent through immersive virtual reality (IVR) may lead to feeling vicariously somatosensory stimuli on one’s body which are in fact never delivered. To explore whether vicarious touch in IVR reflects the basic individual and social features of real-life interpersonal interactions we tested heterosexual men/women and gay men/lesbian women reacting subjectively and physiologically to the observation of a gender-matched virtual body being touched on intimate taboo zones (like genitalia) by male and female avatars. All participants rated as most erogenous caresses on their embodied avatar taboo zones. Crucially, heterosexual men/women and gay men/lesbian women rated as most erogenous taboo touches delivered by their opposite and same gender avatar, respectively. Skin conductance was maximal when taboo touches were delivered by female avatars. Our study shows that IVR may trigger realistic experiences and ultimately allow the direct exploration of sensitive societal and individual issues that can otherwise be explored only through imagination

Performance of dairy cows supplemented with by-pass fat under heat stress conditions

The objective of this study was to determine the effect of supplementation with a protected fat source on the productive response, metabolic environment and physiological indicators in Holstein cows under heat stress conditions during a 12-week experimental period. Thirty Holstein cows were distributed in 15 blocks by parity (2.0 ± 1.1), days in milk (182 ± 80) and milk production (29.4 ± 5.7 kg·day-1) at the beginning of the trial and randomly assigned within each block to the following treatments (diets): SPF: supplementation with protected fat or WPF: without supplementation with protected fat. All the cows were kept in a dry-lot where they were given a partial mixed ration (PMR) ad libitum while in the milking parlor they received individual supplementation depending on the treatment. The SPF diet contained 4.0 kg·day-1 concentrate in pellet form + 0.6 kg·day-1 ground corn grain + 0.7 kg·day-1 protected fat, while the WPF diet was similar to that offered in SPF, but the protected fat was isoenergetically replaced by ground corn grain. The fat supplement contained fats of animal and vegetable origin and microencapsulation was used for its preparation. Total dry matter and metabolic energy intakes were similar (p > 0.05) between treatments. Fat corrected milk (4% FCM) production was higher (p = 0.04), while energy corrected milk and fat productions tended (p = 0.06) to be higher in cows from the SPF group, without effects (p > 0.05) on the rest of the milk production and composition parameters. These results could be attributed to an improvement in the efficiency of the use of the energy consumed. Protected fat supplementation neither modified the metabolic profile, nor reduced the respiratory rate and body temperature of heat-stressed cows. Future research is needed to explain this latter result.EEA RafaelaFil: Roskopf, Pablo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina.Fil: Tieri, Maria Paz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina.Fil: Cuatrin, Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Paraná; Argentina.Fil: Ceron Cucchi, Maria Esperanza. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiologia; Argentina.Fil: Gere, Jose Ignacio. Universidad Tecnológica Nacional. División de Investigación y Desarrollo de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salado, Eloy. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentina

Feeling of ownership over an embodied avatar's hand brings about fast changes of fronto-parietal cortical dynamics

When we look at our body parts, we are immediately aware that they belong to us and we rarely doubt about the integrity, continuity, and sense of ownership of our body. Despite this certainty, immersive virtual reality (IVR) may lead to a strong feeling of embodiment over an artificial body part seen from a first-person perspective (1PP). Although such feeling of ownership (FO) has been described in different situations, it is not yet understood how this phenomenon is generated at neural level. To track the real-time brain dynamics associated with FO, we delivered transcranial magnetic stimuli over the hand region in the primary motor cortex (M1) and simultaneously recorded electroencephalography (EEG) in 19 healthy volunteers (11 male/8 female) watching IVR renderings of anatomically plausible (full-limb) versus implausible (hand disconnected from the forearm) virtual limbs. Our data show that embodying a virtual hand is temporally associated with a rapid drop of cortical activity of the onlookers' hand region in the M1 contralateral to the observed hand. Spatiotemporal analysis shows that embodying the avatar's hand is also associated with fast changes of activity within an interconnected fronto-parietal circuit ipsilateral to the brain stimulation. Specifically, an immediate reduction of connectivity with the premotor area is paralleled by an enhancement in the connectivity with the posterior parietal cortex (PPC) which is related to the strength of ownership illusion ratings and thus likely reflects conscious feelings of embodiment. Our results suggest that changes of bodily representations are underpinned by a dynamic cross talk within a highly-plastic, fronto-parietal network

Indicadores utilizados para evaluar la sustentabilidad integral de los sistemas de producción de leche con énfasis en el impacto ambiental

En este trabajo se presenta una revisión de los principales indicadores utilizados en diferentes países para evaluar la sustentabilidad integral de los sistemas lecheros, realizando hincapié en aquellos indicadores que pueden ser utilizados en la gestión ambiental de los predios en la Argentina. El conocimiento y la sensibilización actual sobre el impacto ambiental y en menor medida, de la producción animal en particular, han desencadenado la investigación sobre el desarrollo de indicadores para evaluar la sustentabilidad ambiental, como por ejemplo los balances de nutrientes, el consumo y la eficiencia en el uso de la energía y el agua, y las emisiones de los sistemas productivos. Estos indicadores deben ser analizados en conjunto con indicadores físicos y económicos utilizados en estos sistemas productivos. La utilización de los mismos ha permitido tener una aproximación del impacto que las prácticas agropecuarias tienen en un sistema productivo y agroecosistema determinado. Los indicadores a escala predial facilitan a los productores el diagnóstico para poder actuar en consecuencia e ir mejorando su condición frente a normativas de regulación que exigen los diferentes mercados y normativas incipientes en las diferentes regiones productivas del país. Encontrar el equilibrio entre la producción lechera y el grado de impacto que puede ser aceptable para la sociedad, es la clave para lograr la producción lechera sustentable, reduciendo al mínimo la contaminación del agua, aire y suelo, preservando y mejorando el medio natural y haciendo un uso racional de los recursos.EEA RafaelaFil: Tieri, Maria Paz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Comeron, Eduardo Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Capece, Maria Gabriela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Herrero, María Alejandra. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Engler, Patricia Laura. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Paraná; ArgentinaFil: Charlon, Veronica. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Garcia, Karina Elizabet. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; Argentin

Dairy foods and health: an umbrella review of observational studies

Evidence on consumption of dairy foods and human health is contradictory. This study aimed to summarize the level of evidence of dairy consumption on various health outcomes. A systematic search for meta-analyses was performed: study design, dose\u2013response relationship, heterogeneity and agreement of results over time, and identification of potential confounding factors were considered to assess the level of evidence. Convincing and probable evidence of decreased risk of colorectal cancer, hypertension and cardiovascular disease, elevated blood pressure and fatal stroke, respectively, was found for total dairy consumption; possible decreased risk of breast cancer, metabolic syndrome, stroke and type-2 diabetes, and increased risk of prostate cancer and Parkinson\u2019s disease was also found. Similar, yet not entirely consistent evidence for individual dairy products was reported. Among potential confounding factors, geographical localisation and fat content of dairy have been detected. In conclusions, dairy may be part of a healthy diet; however, additional studies exploring confounding factors are needed to ascertain the potential detrimental effects