Brainstem neural mechanisms controlling locomotion with special reference to basal vertebrates

Over the last 60 years, the basic neural circuitry responsible for the supraspinal control of locomotion has progressively been uncovered. Initially, significant progress was made in identifying the different supraspinal structures controlling locomotion in mammals as well as some of the underlying mechanisms. It became clear, however, that the complexity of the mammalian central nervous system (CNS) prevented researchers from characterizing the detailed cellular mechanisms involved and that animal models with a simpler nervous system were needed. Basal vertebrate species such as lampreys, xenopus embryos, and zebrafish became models of choice. More recently, optogenetic approaches have considerably revived interest in mammalian models. The mesencephalic locomotor region (MLR) is an important brainstem region known to control locomotion in all vertebrate species examined to date. It controls locomotion through intermediary cells in the hindbrain, the reticulospinal neurons (RSNs). The MLR comprises populations of cholinergic and glutamatergic neurons and their specific contribution to the control of locomotion is not fully resolved yet. Moreover, the downward projections from the MLR to RSNs is still not fully understood. Reporting on discoveries made in different animal models, this review article focuses on the MLR, its projections to RSNs, and the contribution of these neural elements to the control of locomotion. Excellent and detailed reviews on the brainstem control of locomotion have been recently published with emphasis on mammalian species. The present review article focuses on findings made in basal vertebrates such as the lamprey, to help direct new research in mammals, including humans

Lorsque le travail devient invisible. L’action publique et le travail des artistes visuels et de la scène du Québec en contexte de crise sanitaire

Les artistes interprètes et créateurs ont été sévèrement touchés par la crise sanitaire liée à la pandémie de Covid-19 et les données statistiques indiquent que le secteur des arts et de la culture est celui qui a subi les plus fortes pertes, notamment sur le plan de l’emploi et des revenus. Cette analyse cherche à prendre la mesure des effets du confinement et des mesures sanitaires, qui ont conduit notamment à la fermeture prolongée des lieux de diffusion, sur les conditions d’activité des artistes. Le diagnostic avancé met en évidence que l’action publique qui s’est appliquée à ces milieux est en partie décalée de leurs réalités et de leurs enjeux spécifiques. Les effets de ce décalage sont observés à trois niveaux qui sont considérés comme des zones d’invisibilité du travail d’artiste. Ils prennent la forme respectivement (1) d’une fragilisation des interdépendances fonctionnelles dans lesquelles est inséré le travail d’artiste (2) d’une accentuation des processus de précarisation de ces professions et (3) d’effets sur les registres de représentation et identitaires de ces métiers.Creators and performing artists have been severely impacted by the health crisis due to the Covid-19 pandemic. Recent statistics show that the Quebec’s arts and culture sector suffered the most important losses in terms of employment rates and income. This article analyzes and discusses the effects of lockdown and other public health measures, including the prolonged closure of artistic venues, on performing and visual artists’ activity conditions. The diagnosis put forward highlights how the public action dedicated to supporting the arts and culture sector has been partly disconnected from their realities and the specific issues they encounter. The effects of this mismatch can be observed on three levels, which are conceptualized as three invisibility zones of artistic labour. These three zones take, respectively, the form of (1) a weakening of the functional interdependencies in which artistic labour is embedded, (2) a reinforcement of the precarity processes impacting artistic professions and (3) other effects on their representation and identity registers

Algometer Precision for Quantifying Mechanical Nociceptive Threshold When Applied to the Udder of Lactating Dairy Cows.

Objectives of this study were to: (1) quantify the reliability of an algometer for measuring mechanical nociceptive thresholds when applied to the udder of dairy cows; and (2) evaluate whether covariates, such as cow characteristics or time of the day, would influence algometer measurements. This prospective study was performed in a university herd of 37 lactating cows during five consecutive days, involving two raters. Two types of measurement were obtained: one qualitative binary measure (i.e., reaction vs. no reaction) and one quantitative measure presented in kilograms (i.e., mechanical nociceptive threshold, MNT) for the cows that reacted. Kappa statistics were used to investigate test-retest and inter-rater reliability for the qualitative measure, while concordance correlation coefficient (CCC) and limits of agreement plot were used for the quantitative measure. Whether algometer measurements were influenced by several covariates (i.e., time of the day, level of milk production, days in milk, and parity) was then evaluated using logistic or linear regression models, depending on the outcome. The algometer was moderately reliable; there was moderate test-retest reliability (Kappa = 0.53; CCC = 0.58) and inter-rater reliability (Kappa = 0.42; CCC = 0.54). The MNT varied substantially as a function of time of the day and parity. This is the first study reporting reliability of a pressure algometer for quantifying MNT and investigating covariates possibly affecting this measurement when applied to the udder of dairy cows. It is concluded that the use of an algometer for quantifying MNT on the udder is only moderately repeatable and is influenced by extraneous covariates. Its usage in research setting to quantify changes in sensitivity at the udder level should, therefore, be considered very cautiously or it should be further developed

Contribution of Ergotoxicology to the Determination of Actual PPE Effectiveness in Protecting Users From Phytosanitary Risks. From Contamination Analysis to the Collective Whistle-Blowing Process

This paper presents the results of an ergotoxicologic study on the effectiveness, in real-life conditions, of the protective suits recommended by preventionists. The arguments presented in the paper are based on the Pestexpo study conducted by Isabelle Baldi (Baldi et al. (2002) and Baldi et al. (2006)), which involved analyzing the exposure of vineyard workers to plant protection products by using an ergo-toxicologic approach. The point is to identify different types of exposure by taking into account the characteristics of the actual work (as opposed to what the operators are supposed to be doing) as an outcome of personal, technical and organizational determinants. We were able to point at the permeation of the fabric used for some of the suits. Indeed, after further discussion with PPE manufacturers, it would appear that the suits recommended for agricultural activities were initially developed for industrial purposes and that since farming is just a market niche, these suits may not have been tested for plant protection products, not even for the most common ones. We will explore this topic in terms of organizational and technical failure (Reason, 2004) in the personal protective equipment (PPE) design, testing and standardization process. We will also present the collective whistle-blowing process that was initiated.L’objectif de cet article est de présenter des résultats récents d’une recherche/action en ergotoxicologie concernant les risques liés à l’usage des produits phytosanitaires. Cette recherche propose une double articulation : la première entre des résultats issus d’analyses en situations de travail portant sur la contamination externe des viticulteurs et des résultats issus de tests en laboratoire portant sur la perméation des combinaisons. La seconde articulation concerne le lien entre l’ensemble des résultats cités ci-dessus et une analyse des failles techniques et organisationnelles de la conception et des processus de certification des EPI (équipements de protection individuelle). Sur ces bases, la question des EPI sera alors abordée sous l’angle d’un transfert de technologie entre des milieux industriels et les réalités des situations agricoles. Ceci conduit à un diagnostic très préoccupant en matière d’efficacité réelle des combinaisons. Nous aborderons aussi les questions des responsabilités juridiques soulevées par de tels manquements. Enfin, nous détaillerons le rôle de whistler blower (Vaugan, 1996) que nous avons décidé de jouer ainsi que le processus d’alerte que nous avons construit afin de poser autrement le problème des EPI et intéresser l’ensemble des acteurs.El objetivo de este artículo es presentar los resultados recientes de una investigación/acción en ergotoxicología sobre los riesgos relacionados con el uso de productos fitosanitarios. Esta investigación propone una doble articulación : la primera, entre resultados que emergen de análisis realizados en situaciones de trabajo sobre la contaminación externa de los viticultores y resultados provenientes de tests de laboratorio sobre la permeabilidad de la vestimenta de protección. La segunda articulación trata de la relación entre el conjunto de resultados ya citados y un análisis de los fallos técnicos y organizacionales del diseño y de los procesos de certificación de los EPI (equipos de protección individual). La problemática de los EPI será abordada desde el ángulo de una transferencia de tecnología entre los medios industriales y las realidades de las situaciones agrícolas. Esto conduce a un diagnóstico muy preocupante sobre la eficacia real de las vestimentas de protección. Abordaremos también las preguntas sobre la responsabilidad jurídica que emergen de estas carencias. Finalmente, explicaremos el rol de whistler blower (Vaugan, 1996) que decidimos jugar y el proceso de alerta que construimos para plantear de otra manera el problema de los EPI y hacer emerger el interés del conjunto de los actores sobre esta cuestión

Apports de l’ergotoxicologie à l’évaluation de l’efficacité réelle des EPI devant protéger du risque phytosanitaire : de l’analyse de la contamination au processus collectif d’alerte

L’objectif de cet article est de présenter des résultats récents d’une recherche/action en ergotoxicologie concernant les risques liés à l’usage des produits phytosanitaires. Cette recherche propose une double articulation : la première entre des résultats issus d’analyses en situations de travail portant sur la contamination externe des viticulteurs et des résultats issus de tests en laboratoire portant sur la perméation des combinaisons. La seconde articulation concerne le lien entre l’ensemble des résultats cités ci-dessus et une analyse des failles techniques et organisationnelles de la conception et des processus de certification des EPI (équipements de protection individuelle). Sur ces bases, la question des EPI sera alors abordée sous l’angle d’un transfert de technologie entre des milieux industriels et les réalités des situations agricoles. Ceci conduit à un diagnostic très préoccupant en matière d’efficacité réelle des combinaisons. Nous aborderons aussi les questions des responsabilités juridiques soulevées par de tels manquements. Enfin, nous détaillerons le rôle de whistler blower (Vaugan, 1996) que nous avons décidé de jouer ainsi que le processus d’alerte que nous avons construit afin de poser autrement le problème des EPI et intéresser l’ensemble des acteurs.This paper presents the results of an ergotoxicologic study on the effectiveness, in real-life conditions, of the protective suits recommended by preventionists. The arguments presented in the paper are based on the Pestexpo study conducted by Isabelle Baldi (Baldi et al. (2002) and Baldi et al. (2006)), which involved analyzing the exposure of vineyard workers to plant protection products by using an ergo-toxicologic approach. The point is to identify different types of exposure by taking into account the characteristics of the actual work (as opposed to what the operators are supposed to be doing) as an outcome of personal, technical and organizational determinants. We were able to point at the permeation of the fabric used for some of the suits. Indeed, after further discussion with PPE manufacturers, it would appear that the suits recommended for agricultural activities were initially developed for industrial purposes and that since farming is just a market niche, these suits may not have been tested for plant protection products, not even for the most common ones. We will explore this topic in terms of organizational and technical failure (Reason, 2004) in the personal protective equipment (PPE) design, testing and standardization process. We will also present the collective whistle-blowing process that was initiated.El objetivo de este artículo es presentar los resultados recientes de una investigación/acción en ergotoxicología sobre los riesgos relacionados con el uso de productos fitosanitarios. Esta investigación propone una doble articulación : la primera, entre resultados que emergen de análisis realizados en situaciones de trabajo sobre la contaminación externa de los viticultores y resultados provenientes de tests de laboratorio sobre la permeabilidad de la vestimenta de protección. La segunda articulación trata de la relación entre el conjunto de resultados ya citados y un análisis de los fallos técnicos y organizacionales del diseño y de los procesos de certificación de los EPI (equipos de protección individual). La problemática de los EPI será abordada desde el ángulo de una transferencia de tecnología entre los medios industriales y las realidades de las situaciones agrícolas. Esto conduce a un diagnóstico muy preocupante sobre la eficacia real de las vestimentas de protección. Abordaremos también las preguntas sobre la responsabilidad jurídica que emergen de estas carencias. Finalmente, explicaremos el rol de whistler blower (Vaugan, 1996) que decidimos jugar y el proceso de alerta que construimos para plantear de otra manera el problema de los EPI y hacer emerger el interés del conjunto de los actores sobre esta cuestión

Contributos da ergotoxicologia na avaliação da eficácia real dos EPI que devem proteger do risco fitossanitário : da análise da contaminação ao processo colectivo de alerta

O objectivo deste artigo é de apresentar os resultados recentes de uma investigação/acção em ergotoxicologia no que concerne os riscos relacionados com o uso de produtos fitossanitários. Esta investigação propõe uma dupla articulação : a primeira entre os resultados provenientes de análises em situação de trabalho no que diz respeito à contaminação externa dos viticultores e dos resultados provenientes de testes em laboratórios quanto à “permeação” dos fatos de macaco. A segunda articulação incide sobre a relação entre o conjunto dos resultados, acima referidos, e uma análise das falhas técnicas e organizacionais da concepção e dos processos de certificação dos EPI (equipamentos de protecção individual). Tendo isto em conta, a questão dos EPI será então abordada sob a perspectiva de uma transferência de tecnologia entre os meios industriais e as realidades das situações agrícolas. Isto conduz a um diagnóstico muito preocupante em matéria de eficácia real dos fatos de macaco. Abordaremos também as questões das responsabilidades jurídicas levantadas por tais falhas. Finalmente, pormenorizaremos o papel de whistler blower (Vaugan, 1996) que decidimos assumir assim como o processo de alerta que construímos a fim de abordar de outro modo o problema dos EPI e de suscitar interesse no conjunto dos actores.El objetivo de este artículo es el de presentar los resultados recientes de una investigación/acción en ergotoxicología en lo que se refiere a los riesgos relacionados con el uso de productos fitosanitarios. Esta investigación propone una doble articulación : la primera entre los resultados provenientes de análisis en situación de trabajo en lo que se refiere a la contaminación externa de los viticultores y de los resultados provenientes de pruebas en laboratorios en cuanto a la “permeación” de los monos (pieza vestuario). La segunda articulación incide sobre la relación entre el conjunto de los resultados, antes referidos, y un análisis de los fallos técnicos y organizacionales de la concepción y de los procesos de certificación de los EPI (equipos de protección individual). Teniendo esto en cuenta, la cuestión de los EPI será entonces planteada bajo la perspectiva de una transferencia de tecnología entre los medios industriales y las realidades de las situaciones agrícolas. Esto conduce a un diagnóstico muy preocupante en materia de eficacia real de los monos (pieza vestuario). Plantearemos también las cuestiones de las responsabilidades jurídicas levantadas por tales fallos. Finalmente, detallaremos el papel de whistler blower (Vaugan, 1996) que decidimos asumir así como el proceso de alerta que construimos a fin de plantear de otra forma el problema de los EPI y de suscitar interés en el conjunto de los actores.L’objectif de cet article est de présenter des résultats récents d’une recherche/action en ergotoxicologie concernant les risques liés à l’usage des produits phytosanitaires. Cette recherche propose une double articulation : la première entre des résultats issus d’analyses en situations de travail portant sur la contamination externe des viticulteurs et des résultats issus de tests en laboratoire portant sur la perméation des combinaisons. La seconde articulation concerne le lien entre l’ensemble des résultats cités ci-dessus et une analyse des failles techniques et organisationnelles de la conception et des processus de certification des EPI (équipements de protection individuelle). Sur ces bases, la question des EPI sera alors abordée sous l’angle d’un transfert de technologie entre des milieux industriels et les réalités des situations agricoles. Ceci conduit à un diagnostic très préoccupant en matière d’efficacité réelle des combinaisons. Nous aborderons aussi les questions des responsabilités juridiques soulevées par de tels manquements. Enfin, nous détaillerons le rôle de whistler blower (Vaugan, 1996) que nous avons décidé de jouer ainsi que le processus d’alerte que nous avons construit afin de poser autrement le problème des EPI et intéresser l’ensemble des acteurs.This paper aims to present the results of an ergo-toxicologic study of the effectiveness, in real-life conditions, of the protective suits recommended by preventionists. The arguments developed hereafter are based on the Pestexpo study led by Isabelle Baldi (Baldi et al. (2002) and Baldi et al. (2006)). This study focused on analysing the exposure of vineyard workers to plant protection products by using an ergo-toxicologic approach. The point is to identify different types of exposure by taking into account the characteristics of the real work activity (as opposed to what the operators are supposed to be doing) as a produce of personal, technical and organisational determinants. We were able to point at the “permeação” of the fabric used for some of the suits. Indeed, after further discussion with PPE manufacturing companies, it seems that the suits recommended for agricultural activities were initially developed for the needs of the industry, and that as the agriculture is just a niche in terms of sales, those suits may not havebeentestedfor plant protection products, notevenforthose which are most frequently used. We will explore this question along the lines of organisational and technical failures (Reason, 2004) in the processes of design, testing and standardisation of PPE (personal protective equipment). We will also present a collective process of whistle-blowing we have initiated

Incomplete Milking in Early Lactation Does Not Affect Dairy Cows Resting Behaviors: Results from a Randomized Controlled Trial.

The objective of this study was to investigate the effect of incomplete milking during the first 5 days of lactation on the resting behavior of commercial dairy cows. The hypothesis was that the elevated intramammary pressure resulting from milk retained in the udder in incompletely milked cows could lead to a change in lying behavior. This study was a randomized controlled trial in which cows from two farms were randomly allocated into a treatment (n = 18) or a control group (n = 14). Cows in the treatment group were milked incompletely (10-14 L/days) during the first 5 days of lactation, while cows in the control group were milked as usually done on farm. Resting behaviors were recorded with a data logger. Linear mixed models were used to quantify the effects of treatment group on three dependent variables measured between 2 and 14 days in milk: daily duration of lying time (h/d), lying bout frequency (bouts/day), and mean duration of lying bouts (min/bout). There was no significant effect of treatment on lying time. However, the effect of treatment on frequency of lying bouts and on mean lying bout duration varied by parity level. Incompletely milked cows in second parity had a higher number of lying bouts (11.9 vs. 9.2 bouts/day) and shorter mean lying bout duration (57.8 min/bout vs. 66.7 min) than control cows. In third parity or more, the opposite happened. Therefore, our results suggest that an incomplete milking may be slightly problematic for second parity cows and, possibly, slightly beneficial for older cows. Whether the differences observed resulted from a biologic process (discomfort due to the incomplete milking) or from random error will have to be determined by future research

Algometer Precision for Quantifying Mechanical Nociceptive Threshold When Applied to the Udder of Lactating Dairy Cows

Objectives of this study were to: (1) quantify the reliability of an algometer for measuring mechanical nociceptive thresholds when applied to the udder of dairy cows; and (2) evaluate whether covariates, such as cow characteristics or time of the day, would influence algometer measurements. This prospective study was performed in a university herd of 37 lactating cows during five consecutive days, involving two raters. Two types of measurement were obtained: one qualitative binary measure (i.e., reaction vs. no reaction) and one quantitative measure presented in kilograms (i.e., mechanical nociceptive threshold, MNT) for the cows that reacted. Kappa statistics were used to investigate test-retest and inter-rater reliability for the qualitative measure, while concordance correlation coefficient (CCC) and limits of agreement plot were used for the quantitative measure. Whether algometer measurements were influenced by several covariates (i.e., time of the day, level of milk production, days in milk, and parity) was then evaluated using logistic or linear regression models, depending on the outcome. The algometer was moderately reliable; there was moderate test-retest reliability (Kappa = 0.53; CCC = 0.58) and inter-rater reliability (Kappa = 0.42; CCC = 0.54). The MNT varied substantially as a function of time of the day and parity. This is the first study reporting reliability of a pressure algometer for quantifying MNT and investigating covariates possibly affecting this measurement when applied to the udder of dairy cows. It is concluded that the use of an algometer for quantifying MNT on the udder is only moderately repeatable and is influenced by extraneous covariates. Its usage in research setting to quantify changes in sensitivity at the udder level should, therefore, be considered very cautiously or it should be further developed

Evidence for a role of NTS2 receptors in the modulation of tonic pain sensitivity

<p>Abstract</p> <p>Background</p> <p>Central neurotensin (NT) administration results in a naloxone-insensitive antinociceptive response in animal models of acute and persistent pain. Both NTS1 and NTS2 receptors were shown to be required for different aspects of NT-induced analgesia. We recently demonstrated that NTS2 receptors were extensively associated with ascending nociceptive pathways, both at the level of the dorsal root ganglia and of the spinal dorsal horn. Then, we found that spinally administered NTS2-selective agonists induced dose-dependent antinociceptive responses in the acute tail-flick test. In the present study, we therefore investigated whether activation of spinal NTS2 receptors suppressed the persistent inflammatory pain symptoms observed after intraplantar injection of formalin.</p> <p>Results</p> <p>We first demonstrated that spinally administered NT and NT69L agonists, which bind to both NTS1 and NTS2 receptors, significantly reduced pain-evoked responses during the inflammatory phase of the formalin test. Accordingly, pretreatment with the NTS2-selective analogs JMV-431 and levocabastine was effective in inhibiting the aversive behaviors induced by formalin. With resolution at the single-cell level, we also found that activation of spinal NTS2 receptors reduced formalin-induced <it>c-fos </it>expression in dorsal horn neurons. However, our results also suggest that NTS2-selective agonists and NTS1/NTS2 mixed compounds differently modulated the early (21–39 min) and late (40–60 min) tonic phase 2 and recruited endogenous pain inhibitory mechanisms integrated at different levels of the central nervous system. Indeed, while non-selective drugs suppressed pain-related behaviors activity in both part of phase 2, intrathecal injection of NTS2-selective agonists was only efficient in reducing pain during the late phase 2. Furthermore, assessment of the stereotypic pain behaviors of lifting, shaking, licking and biting to formalin also revealed that unlike non-discriminative NTS1/NTS2 analogs reversing all nociceptive endpoint behaviors, pure NTS2 agonists specifically inhibited paw lifting, supporting a role of NTS2 in spinal modulation of persistent nociception.</p> <p>Conclusion</p> <p>The present study provides the first demonstration that activation of NTS2 receptors produces analgesia in the persistent inflammatory pain model of formalin. The dichotomy between these two classes of compounds also indicates that both NTS1 and NTS2 receptors are involved in tonic pain inhibition and implies that these two NT receptors modulate the pain-induced behavioral responses by acting on distinct spinal and/or supraspinal neural circuits. In conclusion, development of NT agonists targeting both NTS1 and NTS2 receptors could be useful for chronic pain management.</p

Wafer-scale detachable monocrystalline Germanium nanomembranes for the growth of III-V materials and substrate reuse

Germanium (Ge) is increasingly used as a substrate for high-performance optoelectronic, photovoltaic, and electronic devices. These devices are usually grown on thick and rigid Ge substrates manufactured by classical wafering techniques. Nanomembranes (NMs) provide an alternative to this approach while offering wafer-scale lateral dimensions, weight reduction, limitation of waste, and cost effectiveness. Herein, we introduce the Porous germanium Efficient Epitaxial LayEr Release (PEELER) process, which consists of the fabrication of wafer-scale detachable monocrystalline Ge NMs on porous Ge (PGe) and substrate reuse. We demonstrate monocrystalline Ge NMs with surface roughness below 1 nm on top of nanoengineered void layer enabling layer detachment. Furthermore, these Ge NMs exhibit compatibility with the growth of III-V materials. High-resolution transmission electron microscopy (HRTEM) characterization shows Ge NMs crystallinity and high-resolution X-ray diffraction (HRXRD) reciprocal space mapping endorses high-quality GaAs layers. Finally, we demonstrate the chemical reconditioning process of the Ge substrate, allowing its reuse, to produce multiple free-standing NMs from a single parent wafer. The PEELER process significantly reduces the consumption of Ge during the fabrication process which paves the way for a new generation of low-cost flexible optoelectronics devices.Comment: 17 pages and 6 figures along with 3 figures in supporting informatio