RESUMO

Social insects live in communities where cooperative actions heavily rely on the individual cognitive abilities of their members. In the honey bee (Apis mellifera), the specialization in nectar or pollen collection is associated with variations in gustatory sensitivity, affecting both associative and non-associative learning. Gustatory sensitivity fluctuates as a function of changes in motivation for the specific floral resource throughout the foraging cycle, yet differences in learning between nectar and pollen foragers at the onset of food collection remain unexplored. Here, we examined nectar and pollen foragers captured upon arrival at food sources. We subjected them to an olfactory proboscis extension reflex (PER) conditioning using a 10% sucrose solution paired (S10%+P) or unpaired (S10%) with pollen as a co-reinforcement. For non-associative learning, we habituated foragers with S10%+P or S10%, followed by dishabituation tests with either a 50% sucrose solution paired (S50%+P) or unpaired (S50%) with pollen. Our results indicate that pollen foragers show lower performance than nectar foragers when conditioned with S10%. Interestingly, performance improves to levels similar to those of nectar foragers when pollen is included as a rewarding stimulus (S10%+P). In non-associative learning, pollen foragers tested with S10%+P displayed a lower degree of habituation than nectar foragers and a higher degree of dishabituation when pollen was used as the dishabituating stimulus (S10%+P). Altogether, our results support the idea that pollen and nectar honey bee foragers differ in their responsiveness to rewards, leading to inter-individual differences in learning that contribute to foraging specialization.

Assuntos

RESUMO

Division of labor is central to the ecological success of social insects. Among foragers of the honey bee, specialization for collecting nectar or pollen correlates with their sensitivity to sucrose. So far, differences in gustatory perception have been mostly studied in bees returning to the hive, but not during foraging. Here, we showed that the phase of the foraging visit (i.e. beginning or end) interacts with foraging specialization (i.e. predisposition to collect pollen or nectar) to modulate sucrose and pollen sensitivity in foragers. In concordance with previous studies, pollen foragers presented higher sucrose responsiveness than nectar foragers at the end of the foraging visit. On the contrary, pollen foragers were less responsive than nectar foragers at the beginning of the visit. Consistently, free-flying foragers accepted less concentrated sucrose solution during pollen gathering than immediately after entering the hive. Pollen perception also changes throughout foraging, as pollen foragers captured at the beginning of the visit learned and retained memories better when they were conditioned with pollen + sucrose as reward than when we used sucrose alone. Altogether, our results support the idea that changes in foragers' perception throughout the foraging visit contributes to task specialization.

Assuntos

RESUMO

Division of labor is central to the ecological success of social insects. Among honeybees foragers, specialization for collecting nectar or pollen correlates with their sensitivity to gustatory stimuli (e.g. sugars). We hypothesize that pollen and nectar foragers also differ in their sensitivity to odors, and therefore in their likelihood to show odor-mediated responses. To assess foragers sensitivity to natural odors, we quantified the conditioning of the proboscis extension reflex (PER) to increasing concentrations (0.001; 0.01; 0.1; 1 M) of linalool or nonanal. Furthermore, we compared electroantennogram (EAG) recordings to correlate bees' conditioned responses with the electrophysiological responses of their antennae. To further explore differences of the antennal response of foragers in relation to task-related odors, we registered EAG signals for two behaviorally ''meaningful'' odors that mediate pollen collection: fresh pollen odors and the brood pheromone (E)-ß-ocimene. Pollen foragers performed better than nectar foragers in PER conditioning trials when linalool and nonanal were presented at low concentrations (0.001, 0.01 M). Consistently, their antennae showed stronger EAG signals (higher amplitudes) to these odors, suggesting that differences in sensitivity can be explained at the periphery of the olfactory system. Pollen and nectar foragers detect pollen odors differently, but not (E)-ß-ocimene. Pollen volatiles evoked EAG signals with hyper and depolarization components. In pollen foragers, the contribution of the hyperpolarization component was higher than in nectar foragers. We discuss our findings in terms of adaptive advantages to learn subtle olfactory cues that influence the ability to better identify/discriminate food sources.

Assuntos

RESUMO

Pollen selection affects honeybee colony development and productivity. Considering that pollen is consumed by young in-hive bees, and not by foragers, we hypothesized that young bees learn pollen cues and adjust their preferences to the most suitable pollens. To assess whether young bees show preferences based on learning for highly or poorly suitable pollens, we measured consumption preferences for two pure monofloral pollens after the bees had experienced one of them adulterated with a deterrent (amygdalin or quinine) or a phagostimulant (linoleic acid). Preferences were obtained from nurse-aged bees confined in cages and from nurse bees in open colonies. Furthermore, we tested the bees' orientation in a Y-maze using a neutral odour (Linalool or Nonanal) that had been previously associated with an amygdalin-adulterated pollen. Consumption preferences of bees, both in cages and in colonies, were reduced for pollens that had been adulterated with deterrents and increased for pollens that had been supplemented with linoleic acid. In the Y-maze, individuals consistently avoided the odours that they had previously experienced paired with the deterrent-adulterated pollen. Results show that nurse-aged bees associate pollen-based or pollen-related cues with either a distasteful/malaise experience or a tasty/nutritious event, leading to memories that bias their pollen-mediated response.

Assuntos

RESUMO

Searching for reward motivates and drives behaviour. In honey bees Apis mellifera, specialized pollen foragers are attracted to and learn odours with pollen. However, the role of pollen as a reward remains poorly understood. Unlike nectar, pollen is not ingested during collection. We hypothesized that pollen (but not nectar) foragers could learn pollen by sole antennal or tarsal stimulation. Then, we tested how pairing of pollen (either hand- or bee-collected) and a neutral odour during a pre-conditioning affects performance of both pollen and nectar foragers during the classical conditioning of the proboscis extension response. Secondly, we tested whether nectar and pollen foragers perceive the simultaneous presentation of pollen (on the tarsi) and sugar (on the antennae) as a better reinforcement than sucrose alone. Finally, we searched for differences in learning of the pollen and nectar foragers when they were prevented from ingesting the reward during the conditioning. Differences in pollen-reinforced learning correlate with division of labour between pollen and nectar foragers. Results show that pollen foragers performed better than nectar foragers during the conditioning phase after being pre-conditioned with pollen. Pollen foragers also performed better than nectar foragers in both the acquisition and extinction phases of the conditioning, when reinforced with the dual reward. Consistently, pollen foragers showed improved abilities to learn cues reinforced without sugar ingestion. We discussed that differences in how pollen and nectar foragers respond to a cue associated with pollen greatly contribute to the physiological mechanism that underlies foraging specialization in the honeybee.

Assuntos

RESUMO

Este trabajo tiene como objetivo principal Indagar el impacto del sistema de residencias médicas sobre el nivel de burnout y la calidad de vida percibida, en profesionales abocados a la salud de la madre y el niño durante el primer año de residencia, evaluando a los residentes al iniciar la residencia y al finalizar el primer año. En total participaron 39 residentes de distintas profesiones. Como instrumentos se emplearon el Maslach Burnout Inventory, el Inventario de Calidad de Vida Percibida y preguntas Ad Hoc sobre el grado de conformidad con la especialidad, nivel de capacitación y clima de trabajo. Como resultado puede observarse que la cantidad de sujetos que presentan indicadores de Burn Out son similares en ambas evaluaciones (inicial y re test), y que la frecuencia de casos en riesgo a desarrollar el síndrome disminuye.

The main objective of this study is to investigate the impact of the medical residency system, on the level of burnout and perceived quality of life among professionals who are concerned with the health of the mother and child during the first year of residency, assessing the professionals at the start of the residence and at the end of the first year. Thirty-nine professionals from different professions participated in the study. The instruments were Maslach Burnout Inventory, the Perceived Life Quality Inventory and Ad Hoc questions on the degree of conformity to the specialty, training level and working climate. As a result, it can be observed that the number of subjects with Burn Out indicators are similar in both evaluations (initial and re-test), and that the frequency of cases at risk of developing the syndrome decreases.

Assuntos

RESUMO

El botulismo por herida es una enfermedad rara, causada por una potente neurotoxina, producida por bacterias de la familia Clostridium. El Clostridium botulinum es la más frecuente, pero existen otras, como el Clostridium baratti y el Clostridium butyricum, que también son productoras de neurotoxinas. Se conocen siete tipos de neurotoxinas (de A a G), entre las cuales los tipos A, B, E, F y G causan botulismo humano. Esta forma, la menos frecuente, resulta de la colonización de una herida por Clostridium botulinum. Clínicamente, es semejante a las otras formas de presentación, pero con fiebre y/o leucocitosis por sobreinfección. La enfermedad debe sospecharse en pacientes lúcidos con parálisis fláccida, simétrica y descendente. Estos síntomas no exceden los 20 días y suelen ser lentos en su presentación, pero más lento suele ser el diagnóstico clínico ya que, muchas veces, se desconoce la enfermedad. El tratamiento es de sostén; la administración de la antitoxina específica debe ser precoz y realizarse antes del debridamiento de la herida infectada.

Botulism is a rare illness caused by a potent neurotoxin produced by the bacterium of the Clostridium family. Clostridium botulinum is the most frequent one, but Clostridium baratti and Clostridium butyricum are also neurotoxins producers. There are seven neurotoxins types, A to G; A, B, E, F and G cause human botulism. Every neurotoxin type blocks cholinergic transmission at the myoneural junction. The least frequent syndrome results from Clostridium botulinum colonization of a wound and it is clinically similar to the other botulism syndromes, but with fever due to an infected wound. Disease should be suspected in lucid patient with a symmetric descending, flaccid paralysis. This syndrome appears within the first twenty days, but it could be present for weeks or months before the disease is diagnosed. This disease is poorly known, so to be diagnosed it requires a high index of suspicion. The treatment is a supportive one; administration of the specific antitoxin must be early in order to neutralize the toxin before the debridement and cleaning of the infected wound.

Assuntos

RESUMO

El botulismo por herida es una enfermedad rara, causada por una potente neurotoxina, producida por bacterias de la familia Clostridium. El Clostridium botulinum es la más frecuente, pero existen otras, como el Clostridium baratti y el Clostridium butyricum, que también son productoras de neurotoxinas. Se conocen siete tipos de neurotoxinas (de A a G), entre las cuales los tipos A, B, E, F y G causan botulismo humano. Esta forma, la menos frecuente, resulta de la colonización de una herida por Clostridium botulinum. Clínicamente, es semejante a las otras formas de presentación, pero con fiebre y/o leucocitosis por sobreinfección. La enfermedad debe sospecharse en pacientes lúcidos con parálisis fláccida, simétrica y descendente. Estos síntomas no exceden los 20 días y suelen ser lentos en su presentación, pero más lento suele ser el diagnóstico clínico ya que, muchas veces, se desconoce la enfermedad. El tratamiento es de sostén; la administración de la antitoxina específica debe ser precoz y realizarse antes del debridamiento de la herida infectada.(AU)

Botulism is a rare illness caused by a potent neurotoxin produced by the bacterium of the Clostridium family. Clostridium botulinum is the most frequent one, but Clostridium baratti and Clostridium butyricum are also neurotoxins producers. There are seven neurotoxins types, A to G; A, B, E, F and G cause human botulism. Every neurotoxin type blocks cholinergic transmission at the myoneural junction. The least frequent syndrome results from Clostridium botulinum colonization of a wound and it is clinically similar to the other botulism syndromes, but with fever due to an infected wound. Disease should be suspected in lucid patient with a symmetric descending, flaccid paralysis. This syndrome appears within the first twenty days, but it could be present for weeks or months before the disease is diagnosed. This disease is poorly known, so to be diagnosed it requires a high index of suspicion. The treatment is a supportive one; administration of the specific antitoxin must be early in order to neutralize the toxin before the debridement and cleaning of the infected wound.(AU)

RESUMO

Botulism is a rare illness caused by a potent neurotoxin produced by the bacterium of the Clostridium family. Clostridium botulinum is the most frequent one, but Clostridium baratti and Clostridium butyricum are also neurotoxins producers. There are seven neurotoxins types, A to G; A, B, E, F and G cause human botulism. Every neurotoxin type blocks cholinergic transmission at the myoneural junction. The least frequent syndrome results from Clostridium botulinum colonization of a wound and it is clinically similar to the other botulism syndromes, but with fever due to an infected wound. Disease should be suspected in lucid patient with a symmetric descending, flaccid paralysis. This syndrome appears within the first twenty days, but it could be present for weeks or months before the disease is diagnosed. This disease is poorly known, so to be diagnosed it requires a high index of suspicion. The treatment is a supportive one; administration of the specific antitoxin must be early in order to neutralize the toxin before the debridement and cleaning of the infected wound.

Assuntos

RESUMO

Botulism is a rare illness caused by a potent neurotoxin produced by the bacterium of the Clostridium family. Clostridium botulinum is the most frequent one, but Clostridium baratti and Clostridium butyricum are also neurotoxins producers. There are seven neurotoxins types, A to G; A, B, E, F and G cause human botulism. Every neurotoxin type blocks cholinergic transmission at the myoneural junction. The least frequent syndrome results from Clostridium botulinum colonization of a wound and it is clinically similar to the other botulism syndromes, but with fever due to an infected wound. Disease should be suspected in lucid patient with a symmetric descending, flaccid paralysis. This syndrome appears within the first twenty days, but it could be present for weeks or months before the disease is diagnosed. This disease is poorly known, so to be diagnosed it requires a high index of suspicion. The treatment is a supportive one; administration of the specific antitoxin must be early in order to neutralize the toxin before the debridement and cleaning of the infected wound.