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Deprez, A., A. Naccache, M. Thomas, E. Louiset, S. Patrier, F. Guimiot, H. Lefebvre y M. Castanet. "Synthèse des minéralocorticoïdes, mastocytes surrénaliens et adaptation à la vie extra-utérine". Annales d'Endocrinologie 78, n.º 4 (septiembre de 2017): 217. http://dx.doi.org/10.1016/j.ando.2017.07.026.
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Gold, F., E. Saliba, V. Biran-Mucignat y D. Mitanchez-Mokhtari. "Physiologie du fœtus et du nouveau-né. Adaptation à la vie extra-utérine". EMC - Pédiatrie - Maladies infectieuses 2, n.º 4 (enero de 2007): 1–20. http://dx.doi.org/10.1016/s1637-5017(07)72385-2.
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Saliba, E., E. Lopez, L. Storme, P. Tourneux y G. Favrais. "Physiologie du fœtus et du nouveau-né – adaptation à la vie extra-utérine". EMC - Pédiatrie - Maladies infectieuses 38, n.º 1 (2018): 1–29. https://doi.org/10.1016/s1637-5017(17)69212-3.
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Toubin, R. M., R. Kojayan, F. Agostini y M. Duport-Percier. "Environnement, pesanteur, émotions, représentations, histoire(s) : comment s’ajuster aux difficultés de l’aîné à l’occasion du suivi de la grossesse ultérieure ?" Périnatalité 13, n.º 2 (junio de 2021): 101. http://dx.doi.org/10.3166/rmp-2021-0120.
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Sur le CHU de Montpellier lors du suivi pédopsychiatrique anténatal, une consultation ciblée sur les étapes sensibles du développement précoce est en place depuis dix ans pour les situations de vulnérabilité majeure. Elle est dénommée consultation « posturage », car elle insiste sur le mouvement actif de regrouper le bébé en posture fœtale pour faciliter son adaptation à la vie extra-utérine en mettant l’accent sur le développement sensorimoteur. Elle est proposée aux futurs parents entre sept et huit mois de grossesse, avec un taux d’acceptation important. Effets de la pesanteur, notion de plasticité cérébrale potentiellement réparatrice de vulnérabilités initiales, programmation biologique émotionnelle chez l’adulte pour répondre à la situation de totale dépendance du bébé sont abordés ainsi que les consignes de couchage et modalités d’alimentation. Il se trouve que le constat des bénéfices sur la mise en place des relations parent–enfants–professionnels a provoqué une forte demande. Les couples sont étonnés de visualiser la simplicité avec laquelle ils pourront assurer une continuité pour le bébé : bain enveloppé, changes sur le côté, regroupement en position fœtale. L’état de réceptivité est tel qu’il provoque un débat animé sur l’enfant aîné : surpris par cette anticipation à laquelle ils ne s’attendaient pas. Les parents prennent conscience d’avoirméconnu les difficultés d’adaptation de ce dernier et se questionnent sur leur genèse ainsi que leur évolution. À leur état d’épuisement associé à un douloureux sentiment d’échec, ils perçoivent une issue en acceptant une orientation pour l’aîné et en s’organisant pour optimiser l’environnement de la naissance à venir. Ainsi, partir des aspects environnementaux sensoriels semble s’avérer plus efficace sur l’alliance thérapeutique que de rechercher les éventuelles difficultés parentales pour y remédier. L’analyse pluridisciplinaire du suivi de 20 situations familiales a mis en exergue de nouvelles problématiques : proposer un bilan psychomoteur rapide sans affoler, tenir compte de l’avis des autres professionnels pour éviter d’exposer le couple à des avis divergents, rester dans l’anticipation de la future naissance, alors que l’attention des parents se focalise sur l’enfant précédent.
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Tolsa, J. F. "Aspects physiologiques de la circulation pulmonaire lors du passage à la vie extra-utérine". Archives de Pédiatrie 7 (mayo de 2000): 269s—270s. http://dx.doi.org/10.1016/s0929-693x(00)80063-9.
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Mitanchez, D., E. Walter-Nicolet, M. Moreno, A. Wallet, C. Renaud, I. de Montgolfier y F. Gold. "Le nouveau-né en maternité: controverses et incertitudes Surveillance de l’adaptation glycémique à la vie extra-utérine". Revue de médecine périnatale 1, n.º 3 (septiembre de 2009): 132–38. http://dx.doi.org/10.1007/s12611-009-0027-2.
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Narvey, Michael R. y Seth D. Marks. "Le dépistage et la prise en charge des nouveau-nés à risque d’hypoglycémie". Paediatrics & Child Health 24, n.º 8 (diciembre de 2019): 545–54. http://dx.doi.org/10.1093/pch/pxz135.
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Résumé L’hypoglycémie entre les premières heures et les premiers jours suivant la naissance demeure l’une des principales affections qu’observent les praticiens du Canada qui s’occupent de nouveau-nés. Bien des cas vivent une transition physiologique normale à la vie extra-utérine, mais un groupe présente une hypoglycémie pendant une plus longue période. Le présent document de principes expose les principaux enjeux auxquels sont exposés les dispensateurs de soins néonatals, y compris la définition d’hypoglycémie, les facteurs de risque, les protocoles de dépistage, les valeurs de glycémie nécessitant une intervention et la gestion des soins pour cette affection. Les auteurs passent en revue le dépistage, la surveillance et les protocoles d’intervention pour mieux distinguer, prendre en charge et traiter les nouveau-nés à risque d’hypoglycémie persistante, récurrente ou marquée. Ils abordent également le rôle des gels de dextrose pour accroître la glycémie ou prévenir une hypoglycémie plus persistante, de même que les précautions à prendre pour réduire les risques de récurrence après le congé de l’hôpital. Le présent document de principes distingue les approches des soins de l’hypoglycémie pendant la « phase de transition » (les 72 premières heures de vie) de celles de l’hypoglycémie persistante, qui se manifeste ou est constatée pour la première fois après cette période.
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Mabaga, Joëlle M., Gray Kanteng, Stéphanie L. Ngimbi, Alex K. Beya, Augustin A. Talona, Lingule Obotela, Fabrice K. Sangwa et al. "Connaissances, attitudes et pratiques des prestataires de soins concernant les urgences néonatales à Lubumbashi". Revue de l’Infirmier Congolais 6, n.º 1 (11 de enero de 2022): 10–16. http://dx.doi.org/10.62126/zqrx.2022612.
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Introduction. Toute perturbation de l’adaptation à la vie extra-utérine est également source importante de morbidité et de mortalité et les causes les plus fréquentes de décès chez les nouveau-nés sont les complications dues à une naissance prématurée, les infections du nouveau-né et l’asphyxie périnatale. Le but de cette étude est d’évaluer les connaissances, attitudes et pratiques (CAP) déclarées parmi les prestataires de soins concernant les urgences néonatales à Lubumbashi. Matériel et méthodes. Il s’agit d’une étude semi-qualitative portant sur les connaissances, attitudes et pratiques des prestataires de soins des services de néonatologie des hôpitaux ci-haut cités et couvrant la période allant du 1er février au 31 mars 2019, soit une durée de 2 mois. Résultats. La qualification était des Médecins résidents en pédiatrie dans 34,6% et l’âge était 35-44 ans dans 53,8% et la formation en soins néonatals était bénéficiée dans 38,7%. Le réchauffement des prématurés était la mesure d’accueil (100%). Les prestataires des soins disaient qu’il faut 2 personnes lors de la réanimation (38,5%), la réanimation se déroule dans la position de la tête près du réanimateur (92,3%) et plus de 10 réanimations au cours de 6 derniers mois fait par les prestataires (53,8%). La prise en charge des prématurés était basée sur le glucose dans 88,5%. Conclusion. La connaissance sur la prématurité contribue à une bonne attitude des prestataires face aux pathologies néonatale et réduire la morbidité. Mots-clés : Connaissances, attitudes, prestataires des soins, urgences néonatales.
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Schneider. "Geburtshilfliche Überlegungen im Grenzbereich der Lebensfähigkeit sehr früher Frühgeburten". Praxis 92, n.º 13 (1 de marzo de 2003): 585–89. http://dx.doi.org/10.1024/0369-8394.92.13.585.
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A la suite de progrès importants de la médecine périnatale, les frontières de la survie extra-utérine ont toujours été plus reculées. Des résultats optimaux exigent une collaboration soigneusement établie selon un protocole adéquat entre les obstétriciens et les néonatologues. De la qualité de ces efforts interdisciplinaires ne dépend pas seulement le taux de survie mais aussi le nombre de survivants ayant une grande probabilité de développement normal et une qualité de vie correspondante. Avant la 24ème semaine de grossesse, la survie descend au-dessous de 10% et plus de la moitié des survivants ont un handicap moyen à sévère. Dans ce domaine, tant de la part des obstétriciens que des néonatologues, aucune médecine interventionnelle n'est indiquée. Un soutien psychologique des parents et des enfants est assuré dans le but de diminuer leurs souffrances. Après la 26ème semaine de grossesse le taux de survie augmente rapidement au-dessus de 50% et le nombre de survivants handicapés diminue en dessous de 50%. Dès la 26ème semaine de grossesse toutes les interventions à disposition sur la grossesse ainsi que toutes les mesures interventionnelles en néonatologie sont recommandées. Dans la zone grise de la 24ème et la 25ème semaine, on recommande une approche individuelle en tenant compte de particularités de chaque cas en accord avec les parents. Les tableaux cliniques les plus fréquents en prénatalogie se laissent classer en trois catégories principales qui sont présentées plus en détail.
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Coulibaly, D. "Contribution à l’amélioration des pratiques de soins essentiels aux nouveau-nés dans le centre de communautaire et universitaire (CSCom U) de Konobougou". Mali Santé Publique 11, n.º 1 (4 de agosto de 2021): 94–100. http://dx.doi.org/10.53318/msp.v11i1.1900.
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Introduction : La période postnatale immédiate est une étape fondamentale d’adaptation physiologique et psychologique pour le nouveau-né. La plupart des difficultés d'adaptation à la vie extra-utérine sont prévisibles et doivent être anticipées. Le but de cette étude était de contribuer à l’amélioration des pratiques de soins essentiels aux nouveau-nés dans le centre de santé communautaire et universitaire (CSCom-U) de Konobougou. Matériel et méthodes : Il s’agissait d’une étude de recherche action qui s’est déroulée dans la maternité du CSCom U de Konobougou dans le district sanitaire de Barouéli/Région de Ségou du 01 décembre 2020 au 31 janvier 2021. Nous avons introduit dans cette étude 32 mères et 8 agents de santé. Résultats : Les matrones étaient plus représentées avec 62,5% suivies des sages-femmes avec 25%. Avant l’enquête tous les matériels étaient disponibles sauf la sonde naso-gastrique. Suite à notre recommandation l’équipe a décidé de s’en procurer une, ce qui a permis de porter la disponibilité des matériels à 100%. A la phase initiale de l’étude, 25% des mères enquêtées avaient reçu des consignes sur les soins du cordon ombilical, suite à la mise à niveau des prestataires nous avons obtenu une augmentation de 75% à la phase finale soit 100%. Conclusion : Les soins essentiels du nouveau-né restaient insuffisants pour déficit de formation initiale et/ou continue d’une part et pour instabilité du personnel d’autre part. Ainsi, nous avons recommandé une mise en place de programme de formation continue et de suivi-évaluation destiné aux prestataires.
Mots clés : Soins essentiels, nouveau-nés, centre de communautaire et universitaire, Konobougou
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Matega, Teddy Habiragi, Yvette Ufoymungu Neema, Jean-Jeannot Syhalikyolo Juakali y Gédéon Bosunga Katenga. "Déclenchement spontané du travail d’accouchement sur une grossesse à terme d’un foetus anencéphale : une observation clinique inhabituelle". Annales Africaines de Medecine 15, n.º 3 (4 de julio de 2022): e4719-e4722. http://dx.doi.org/10.4314/aamed.v15i3.9.
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Le stress foetal survenant au terme de la grossesse, lié au pic de production de la corticotropin releasing hormone, considérée comme l’horloge placentaire, est le déclencheur spontané du travail d’accouchement par stimulation de l’axe corticotrope. Ce mécanisme, cependant, par défait de synthèse de l’hormone adrénocorticotrope secondaire à l’aplasie hypothalamo-hypophysaire fait défaut chez le foetus anencéphale. En effet, l’anencéphalie s’accompagne presque toujours du dépassement de terme de la grossesse en absence de l’hydramnios. Par contre, associée à ce dernier, elle conduit à un accouchement prématuré. Nous rapportons un cas de déclenchement spontané du travail d’accouchement sur une grossesse de trente-huit semaines et un jour. La gestante avait une circulation veineuse collatérale au niveau de la paroi abdominale, la hauteur utérine était de 41 centimètres, l’échographie réalisée avait objectivé un foetus anencéphale associé à un polyhydramnios. Le nouveau-né était décédé sept minutes après l’accouchement. Ainsi, bien que très rare, l’anencéphalie associée au polyhydramnios peut atteindre le terme de la grossesse. L’échographie du deuxième trimestre devrait être réalisée chez toute les gestantes pour dépister cette malformation et arrêter l’évolution de la grossesse, car cette pathologie est incompatible avec la vie extra-utérine.
English title: Spontaneous induction of labor in a full-term pregnancy of an anencephalic fetus: an unusual case report
The fetal stress occurring at the end of pregnancy is linked to the peak of corticotropin-releasing hormone which is considered as the marker of placental clock. This stress is the spontaneous trigger of labor by stimulation of the corticotropic axis. In the anencephalic fetus, this mechanism is lacking due to the absence of synthesis of adrenocorticotropic hormone secondary to hypothalamic-pituitary aplasia. In fact, anencephaly is almost always accompanied by the post-term pregnancy in the absence of hydramnios. However, when associated with hydramnios, it leads to premature delivery. We report a case of spontaneous induction of labor in pregnancy of thirty-eight weeks and one day. The pregnant woman had a collateral venous circulation in the abdominal wall, the uterine height was 41 centimeters, and the ultrasound scan showed an anencephalic fetus associated with polyhydramnios. The newborn died seven minutes after delivery. Therefore, although very rare, anencephaly associated with polyhydramnios can reach term. The second-trimester ultrasound should be performed in all pregnant women to detect this malformation and stop the evolution of the pregnancy because this pathology is incompatible with extrauterine life.
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Wang, Jinsung y Robert L. Sainburg. "Interlimb Transfer of Novel Inertial Dynamics Is Asymmetrical". Journal of Neurophysiology 92, n.º 1 (julio de 2004): 349–60. http://dx.doi.org/10.1152/jn.00960.2003.
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Mechanisms underlying interlimb transfer of adaptation to visuomotor rotations have recently been explored in depth. However, little data are available regarding interlimb transfer of adaptation to novel inertial dynamics. The present study thus investigated interlimb transfer of dynamics by examining the effect of initial training with one arm on subsequent performance with the other in adaptation to a 1.5-kg mass attached eccentrically to the forearm. Using inverse dynamic analysis, we examined the changes in torque strategies associated with adaptation to the extra mass, and with interlimb transfer of that adaptation. Following initial training with the dominant arm, nondominant arm performance improved substantially in terms of linearity and initial direction control as compared with naïve performance. However, initial training with the nondominant arm had no effect on subsequent performance with the dominant arm. Inverse dynamic analysis revealed that improvements in kinematics were implemented by increasing flexor muscle torques at the elbow to counter load-induced increases in extensor interaction torques as well as increasing flexor muscle torques at the shoulder to counter the extensor actions of elbow muscle torque. Following opposite arm adaptation, the nondominant arm adopted this dynamic strategy early in adaptation. These findings suggest that dominant arm adaptation to novel inertial dynamics leads to information that can be accessed and utilized by the opposite arm controller, but not vice versa. When compared with our previous findings on interlimb transfer of visuomotor rotations, our current findings suggest that adaptations to visuomotor and dynamic transformations are mediated by distinct neural mechanisms.
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Hollensteiner, Jacqueline, Dominik Schneider, Anja Poehlein, Thorsten Brinkhoff y Rolf Daniel. "Pan-genome analysis of six Paracoccus type strain genomes reveal lifestyle traits". PLOS ONE 18, n.º 12 (20 de diciembre de 2023): e0287947. http://dx.doi.org/10.1371/journal.pone.0287947.
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The genus Paracoccus capable of inhabiting a variety of different ecological niches both, marine and terrestrial, is globally distributed. In addition, Paracoccus is taxonomically, metabolically and regarding lifestyle highly diverse. Until now, little is known on how Paracoccus can adapt to such a range of different ecological niches and lifestyles. In the present study, the genus Paracoccus was phylogenomically analyzed (n = 160) and revisited, allowing species level classification of 16 so far unclassified Paracoccus sp. strains and detection of five misclassifications. Moreover, we performed pan-genome analysis of Paracoccus-type strains, isolated from a variety of ecological niches, including different soils, tidal flat sediment, host association such as the bluespotted cornetfish, Bugula plumosa, and the reef-building coral Stylophora pistillata to elucidate either i) the importance of lifestyle and adaptation potential, and ii) the role of the genomic equipment and niche adaptation potential. Six complete genomes were de novo hybrid assembled using a combination of short and long-read technologies. These Paracoccus genomes increase the number of completely closed high-quality genomes of type strains from 15 to 21. Pan-genome analysis revealed an open pan-genome composed of 13,819 genes with a minimal chromosomal core (8.84%) highlighting the genomic adaptation potential and the huge impact of extra-chromosomal elements. All genomes are shaped by the acquisition of various mobile genetic elements including genomic islands, prophages, transposases, and insertion sequences emphasizing their genomic plasticity. In terms of lifestyle, each mobile genetic elements should be evaluated separately with respect to the ecological context. Free-living genomes, in contrast to host-associated, tend to comprise (1) larger genomes, or the highest number of extra-chromosomal elements, (2) higher number of genomic islands and insertion sequence elements, and (3) a lower number of intact prophage regions. Regarding lifestyle adaptations, free-living genomes share genes linked to genetic exchange via T4SS, especially relevant for Paracoccus, known for their numerous extrachromosomal elements, enabling adaptation to dynamic environments. Conversely, host-associated genomes feature diverse genes involved in molecule transport, cell wall modification, attachment, stress protection, DNA repair, carbon, and nitrogen metabolism. Due to the vast number of adaptive genes, Paracoccus can quickly adapt to changing environmental conditions.
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Ordoñez, Alba, Line Eikvil, Arnt-Børre Salberg, Alf Harbitz y Bjarki Þór Elvarsson. "Automatic Fish Age Determination across Different Otolith Image Labs Using Domain Adaptation". Fishes 7, n.º 2 (18 de marzo de 2022): 71. http://dx.doi.org/10.3390/fishes7020071.
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The age determination of fish is fundamental to marine resource management. This task is commonly done by analysis of otoliths performed manually by human experts. Otolith images from Greenland halibut acquired by the Institute of Marine Research (Norway) were recently used to train a convolutional neural network (CNN) for automatically predicting fish age, opening the way for requiring less human effort and availability of expertise by means of deep learning (DL). In this study, we demonstrate that applying a CNN model trained on images from one lab (in Norway) does not lead to a suitable performance when predicting fish ages from otolith images from another lab (in Iceland) for the same species. This is due to a problem known as dataset shift, where the source data, i.e., the dataset the model was trained on have different characteristics from the dataset at test stage, here denoted as target data. We further demonstrate that we can handle this problem by using domain adaptation, such that an existing model trained in the source domain is adapted to perform well in the target domain, without requiring extra annotation effort. We investigate four different approaches: (i) simple adaptation via image standardization, (ii) adversarial generative adaptation, (iii) adversarial discriminative adaptation and (iv) self-supervised adaptation. The results show that the performance varies substantially between the methods, with adversarial discriminative and self-supervised adaptations being the best approaches. Without using a domain adaptation approach, the root mean squared error (RMSE) and coefficient of variation (CV) on the Icelandic dataset are as high as 5.12 years and 28.6%, respectively, whereas by using the self-supervised domain adaptation, the RMSE and CV are reduced to 1.94 years and 11.1%. We conclude that careful consideration must be given before DL-based predictors are applied to perform large scale inference. Despite that, domain adaptation is a promising solution for handling problems of dataset shift across image labs.
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Xing, Jinwei, Takashi Nagata, Kexin Chen, Xinyun Zou, Emre Neftci y Jeffrey L. Krichmar. "Domain Adaptation In Reinforcement Learning Via Latent Unified State Representation". Proceedings of the AAAI Conference on Artificial Intelligence 35, n.º 12 (18 de mayo de 2021): 10452–59. http://dx.doi.org/10.1609/aaai.v35i12.17251.
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Despite the recent success of deep reinforcement learning (RL), domain adaptation remains an open problem. Although the generalization ability of RL agents is critical for the real-world applicability of Deep RL, zero-shot policy transfer is still a challenging problem since even minor visual changes could make the trained agent completely fail in the new task. To address this issue, we propose a two-stage RL agent that first learns a latent unified state representation (LUSR) which is consistent across multiple domains in the first stage, and then do RL training in one source domain based on LUSR in the second stage. The cross-domain consistency of LUSR allows the policy acquired from the source domain to generalize to other target domains without extra training. We first demonstrate our approach in variants of CarRacing games with customized manipulations, and then verify it in CARLA, an autonomous driving simulator with more complex and realistic visual observations. Our results show that this approach can achieve state-of-the-art domain adaptation performance in related RL tasks and outperforms prior approaches based on latent-representation based RL and image-to-image translation.
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Yaouanc Lapalle, H. "La mesure de la saturation en O2 au niveau du pied en maternité à deux heures de vie en vue d’une amélioration du dépistage des cardiopathies congénitales est faisable et le résultat est supérieur ou égal à 98 % chez les nouveau-nés s’adaptant normalement à la vie extra-utérine". Revue de médecine périnatale 4, n.º 1 (13 de enero de 2012): 46–47. http://dx.doi.org/10.1007/s12611-011-0165-1.
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Yang, Euijung y Michael C. Dorneich. "Affect-Aware Adaptive Tutoring Based on Human–Automation Etiquette Strategies". Human Factors: The Journal of the Human Factors and Ergonomics Society 60, n.º 4 (28 de marzo de 2018): 510–26. http://dx.doi.org/10.1177/0018720818765266.
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Objective: We investigated adapting the interaction style of intelligent tutoring system (ITS) feedback based on human–automation etiquette strategies. Background: Most ITSs adapt the content difficulty level, adapt the feedback timing, or provide extra content when they detect cognitive or affective decrements. Our previous work demonstrated that changing the interaction style via different feedback etiquette strategies has differential effects on students’ motivation, confidence, satisfaction, and performance. The best etiquette strategy was also determined by user frustration. Method: Based on these findings, a rule set was developed that systemically selected the proper etiquette strategy to address one of four learning factors (motivation, confidence, satisfaction, and performance) under two different levels of user frustration. We explored whether etiquette strategy selection based on this rule set (systematic) or random changes in etiquette strategy for a given level of frustration affected the four learning factors. Participants solved mathematics problems under different frustration conditions with feedback that adapted dynamic changes in etiquette strategies either systematically or randomly. Results: The results demonstrated that feedback with etiquette strategies chosen systematically via the rule set could selectively target and improve motivation, confidence, satisfaction, and performance more than changing etiquette strategies randomly. The systematic adaptation was effective no matter the level of frustration for the participant. Conclusion: If computer tutors can vary the interaction style to effectively mitigate negative emotions, then ITS designers would have one more mechanism in which to design affect-aware adaptations that provide the proper responses in situations where human emotions affect the ability to learn.
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Wu, Chengxiang y Yuanan Lu. "High-titre retroviral vector system for efficient gene delivery into human and mouse cells of haematopoietic and lymphocytic lineages". Journal of General Virology 91, n.º 8 (1 de agosto de 2010): 1909–18. http://dx.doi.org/10.1099/vir.0.020255-0.
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Genetically modified cells of haematopoietic and lymphocytic lineages could provide potentially curative treatments for a wide range of inherited and acquired diseases. However, this application is limited in mouse models by the low efficiency of lentiviral vectors. To facilitate the rapid production of high-titre helper-free retroviral vectors for enhanced gene delivery, multiple modifications to a prototype moloney murine leukemia virus (MoMLV)-derived vector system were made including adaptation of the vector system to simian virus 40 ori/T antigen-mediated episomal replication in packaging cells, replacement of the MoMLV 5′ U3 promoter with a series of stronger composite promoters and addition of an extra polyadenylation signal downstream of the 3′ long terminal repeat. These modifications enhanced vector production by 2–3 logs. High-titre vector stocks were tested for their ability to infect a variety of cells derived from humans and mice, including primary monocyte-derived macrophage cultures. Whilst the lentiviral vector was significantly restricted at the integration level, the MoMLV-based vector showed effective gene transduction of mouse cells. This high-titre retroviral vector system represents a useful tool for efficient gene delivery into human and mouse haematopoietic and lymphocytic cells, with particular application in mice as a small animal model for novel gene therapy tests.
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Ricke, J., L. Kleinholz, N. Hosten, W. Zendel, A. Lemke, W. Wielgus, K. H. Vöge, E. Fleck, R. Marciniak y R. Felix. "Telemedicine in Rural Areas. Experience with Medical Desktop-Conferencing via Satellite". Journal of Telemedicine and Telecare 1, n.º 4 (diciembre de 1995): 224–28. http://dx.doi.org/10.1177/1357633x9500100406.
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Cooperation between physicians in hospitals in rural areas can be assisted by desktop-conferencing using a satellite link. For six weeks, medical desktop-conferencing was tested during daily clinical conferences between the Virchow-Klinikum, Berlin, and the Medical Academy, Wroclaw. The communications link was provided by the German Telekom satellite system MCS, which allowed temporary connections to be established on demand by manual dialling. Standard hardware and software were used for videoconferencing, as well as software for medical communication developed in the BERMED project. Digital data, such as computed tomography or magnetic resonance images, were transmitted by a digital data channel in parallel to the transmission of analogue video and audio signals. For conferences involving large groups of people, hardware modifications were required. These included the installation of a video projector, adaptation of the audio system with improved echo cancellation, and installation of extra microphones. Learning to use an unfamiliar communication medium proved to be uncomplicated for the participating physicians.
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Chu, Lei, Hao Pan y Wenping Wang. "Unsupervised Shape Completion via Deep Prior in the Neural Tangent Kernel Perspective". ACM Transactions on Graphics 40, n.º 3 (4 de julio de 2021): 1–17. http://dx.doi.org/10.1145/3459234.
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We present a novel approach for completing and reconstructing 3D shapes from incomplete scanned data by using deep neural networks. Rather than being trained on supervised completion tasks and applied on a testing shape, the network is optimized from scratch on the single testing shape to fully adapt to the shape and complete the missing data using contextual guidance from the known regions. The ability to complete missing data by an untrained neural network is usually referred to as the deep prior . In this article, we interpret the deep prior from a neural tangent kernel (NTK) perspective and show that the completed shape patches by the trained CNN are naturally similar to existing patches, as they are proximate in the kernel feature space induced by NTK. The interpretation allows us to design more efficient network structures and learning mechanisms for the shape completion and reconstruction task. Being more aware of structural regularities than both traditional and other unsupervised learning-based reconstruction methods, our approach completes large missing regions with plausible shapes and complements supervised learning-based methods that use database priors by requiring no extra training dataset and showing flexible adaptation to a particular shape instance.
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Li, Xiang-Yi, Andrew Morozov y Wolfgang Goymann. "Coevolution of female fidelity and male help in populations with alternative reproductive tactics". Proceedings of the Royal Society B: Biological Sciences 288, n.º 1943 (27 de enero de 2021): 20202371. http://dx.doi.org/10.1098/rspb.2020.2371.
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In socially monogamous species, pair-bonded males often continue to provide care to all offspring in their nests despite some degree of paternity loss due to female extra-pair copulation. Previous theoretical models suggested that females can use their within-pair offspring as ‘hostages' to blackmail their social mates, so that they continue to provide care to the brood at low levels of cuckoldry. These models, however, rely on the assumption of sufficiently accurate male detection of cuckoldry and the reduction of parental effort in case of suspicion. Therefore, they cannot explain the abundant cases where cuckolded males continue to provide extensive care to the brood. Here we use an analytical population genetics model and an individual-based simulation model to explore the coevolution of female fidelity and male help in populations with two genetically determined alternative reproductive tactics (ARTs): sneakers that achieve paternity solely via extra-pair copulations and bourgeois that form a mating pair and spend some efforts in brood care. We show that when the efficiency of mate guarding is intermediate, the bourgeois males can evolve to ‘specialize' in providing care by spending more than 90% of time in helping their females while guarding them as much as possible, despite frequent cuckoldry by the sneakers. We also show that when sneakers have tactic-specific adaptations and thus are more competitive than the bourgeois in gaining extra-pair fertilizations, the frequency of sneakers and the degrees of female fidelity and male help can fluctuate in evolutionary cycles. Our theoretical predictions highlight the need for further empirical tests in species with ARTs.
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Hancock, Steven J., Alvin W. Lo, Thomas Ve, Christopher J. Day, Lendl Tan, Alejandra A. Mendez, Minh-Duy Phan et al. "Ucl fimbriae regulation and glycan receptor specificity contribute to gut colonisation by extra-intestinal pathogenic Escherichia coli". PLOS Pathogens 18, n.º 6 (14 de junio de 2022): e1010582. http://dx.doi.org/10.1371/journal.ppat.1010582.
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Extra-intestinal pathogenic Escherichia coli (ExPEC) belong to a critical priority group of antibiotic resistant pathogens. ExPEC establish gut reservoirs that seed infection of the urinary tract and bloodstream, but the mechanisms of gut colonisation remain to be properly understood. Ucl fimbriae are attachment organelles that facilitate ExPEC adherence. Here, we investigated cellular receptors for Ucl fimbriae and Ucl expression to define molecular mechanisms of Ucl-mediated ExPEC colonisation of the gut. We demonstrate differential expression of Ucl fimbriae in ExPEC sequence types associated with disseminated infection. Genome editing of strains from two common sequence types, F11 (ST127) and UTI89 (ST95), identified a single nucleotide polymorphism in the ucl promoter that changes fimbriae expression via activation by the global stress-response regulator OxyR, leading to altered gut colonisation. Structure-function analysis of the Ucl fimbriae tip-adhesin (UclD) identified high-affinity glycan receptor targets, with highest affinity for sialyllacto-N-fucopentose VI, a structure likely to be expressed on the gut epithelium. Comparison of the UclD adhesin to the homologous UcaD tip-adhesin from Proteus mirabilis revealed that although they possess a similar tertiary structure, apart from lacto-N-fucopentose VI that bound to both adhesins at low-micromolar affinity, they recognize different fucose- and glucose-containing oligosaccharides. Competitive surface plasmon resonance analysis together with co-structural investigation of UcaD in complex with monosaccharides revealed a broad-specificity glycan binding pocket shared between UcaD and UclD that could accommodate these interactions. Overall, our study describes a mechanism of adaptation that augments establishment of an ExPEC gut reservoir to seed disseminated infections, providing a pathway for the development of targeted anti-adhesion therapeutics.
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SAWYER, ROY T. "Biology, morphology and taxonomy of a snail-feeding leech from North Carolina, USA, provisionally identified as Helobdella lineata (Verrill, 1874) (Glossiphoniidae): First evidence for extra-oral digestion in the Hirudinea". Zootaxa 5453, n.º 2 (20 de mayo de 2024): 151–82. http://dx.doi.org/10.11646/zootaxa.5453.2.1.
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This is a twelve-year longitudinal study of a common snail-feeding leech indigenous to the Albemarle region of northeastern North Carolina, USA. Based on contents of this paper the species is provisionally identified as Helobdella lineata (Verrill, 1874). For all practical purposes this is the first comprehensive description of this species. Particular attention is focused on variability of its dorsal papillae and variable pigment patterns within the Albemarle population. A total of 404 specimens were collected from 25 collecting stations in disparate parts of the region. Specialised leech traps set in these swamps were monitored regularly yielding unprecedented information on its morphology, ecology and general biology. This study recognises four principal pigment variants within the Albemarle region which, based on dissections, appear to represent a single biological species. Moreover, limited observations suggest that pigment variability is attributable primarily to adaptive camouflage to local surroundings. Methodologically it is emphasized in this paper that variable traits cannot serve as key taxonomic anchors. A proposed alternative diagnosis for identifying H. lineata is based entirely on more rigorous, non-variable characters. A significant finding is that H. lineata is most meaningfully understood in terms of specialist adaptation to feeding on snails. Furthermore, it is proposed that such adaptation required a major evolutionary shift within the foregut of this species. Evidence is presented that H. lineata uses uniquely large salivary cells to dissolves solid snail tissue into a semi-fluid state before ingestion via a specialised proboscis. This is the first example of extra-oral digestion in the Hirudinea.
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Zabelkin, Alexey, Yulia Yakovleva, Olga Bochkareva y Nikita Alexeev. "PaReBrick: PArallel REarrangements and BReaks identification toolkit". Bioinformatics 38, n.º 2 (2 de octubre de 2021): 357–63. http://dx.doi.org/10.1093/bioinformatics/btab691.
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Abstract Motivation High plasticity of bacterial genomes is provided by numerous mechanisms including horizontal gene transfer and recombination via numerous flanking repeats. Genome rearrangements such as inversions, deletions, insertions and duplications may independently occur in different strains, providing parallel adaptation or phenotypic diversity. Specifically, such rearrangements might be responsible for virulence, antibiotic resistance and antigenic variation. However, identification of such events requires laborious manual inspection and verification of phyletic pattern consistency. Results Here, we define the term ‘parallel rearrangements’ as events that occur independently in phylogenetically distant bacterial strains and present a formalization of the problem of parallel rearrangements calling. We implement an algorithmic solution for the identification of parallel rearrangements in bacterial populations as a tool PaReBrick. The tool takes a collection of strains represented as a sequence of oriented synteny blocks and a phylogenetic tree as input data. It identifies rearrangements, tests them for consistency with a tree, and sorts the events by their parallelism score. The tool provides diagrams of the neighbors for each block of interest, allowing the detection of horizontally transferred blocks or their extra copies and the inversions in which copied blocks are involved. We demonstrated PaReBrick’s efficiency and accuracy and showed its potential to detect genome rearrangements responsible for pathogenicity and adaptation in bacterial genomes. Availability and implementation PaReBrick is written in Python and is available on GitHub: https://github.com/ctlab/parallel-rearrangements. Supplementary information Supplementary data are available at Bioinformatics online.
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Matthijs, Hans C. P., Robert Jeanjean, Nataliya Yeremenko, Jef Huisman, Francoise Joset y Klaas J. Hellingwerf. "Hypothesis: versatile function of ferredoxin-NADP+ reductase in cyanobacteria provides regulation for transient photosystem I-driven cyclic electron flow". Functional Plant Biology 29, n.º 3 (2002): 201. http://dx.doi.org/10.1071/pp01197.
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Pseudo-reversion of the high-CO2 requiring phenotype of the NADH dehydrogenase type 1-impaired mutant of Synechocystis PCC6803, strain M55, by salt stress coincides with partial restoration of PSI-driven cyclic electron transfer. In M55, the complete family of D proteins (D1–D6) that are needed for electron transfer through the complex is lacking. Adaptation to salt stress requires de novo synthesis of full-length 47-kDa ferredoxin-NADP+ reductase (FNR). A mutant created in the M55 background, which only expresses truncated chloroplast 37-kDa FNR cannot adapt to salt stress and refrains from growth in low CO2. A special feature of FNR in cyanobacteria is the relatively high molecular mass of 44–48 kDa. A positively charged extended N-terminal domain of the cyanobacterial enzyme defines the extra mass. The extension likely plays a key role in the salt-stress inducible enhancement of PSI-driven cyclic electron transfer, and in the pseudo-reversion of the high-CO2 requiring phenotype of M55. Data acquired with several other cyanobacteria and the oxychlorobacterium Prochlorothrix hollandica contributed to the present hypothesis. It proposes that FNR is involved in regulation of inducible and transient PSI cyclic electron transfer in cyanobacteria via a thylakoid surface charge and conditional-proteolysis steered mechanism.
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Hardini, Tri Indri y Philippe Grangé. "AN OVERVIEW OF INDONESIAN LOANWORDS FROM FRENCH". Indonesian Journal of Applied Linguistics 6, n.º 1 (29 de julio de 2016): 155. http://dx.doi.org/10.17509/ijal.v6i1.2749.
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When two languages come into contact, they exert a reciprocal influence, often unbalanced. A phenomenon that often occurs in case of language contact is the absorption or borrowing of lexical elements, which will enrich the vocabulary of the receiving language. In this article, we deal with words adopted from French in Indonesian and vice-versa. This research shows that most of the words of French origin in Indonesian/Malay language were borrowed through Dutch. Historical background explains why there are no direct loanwords from French language in Indonesian. Nowadays, a second batch of words originating from Old French finds their way into Indonesian through English. On the other hand, very few words from Malay-Indonesian origin were borrowed in French, and their route was not straight either: they were conveyed through Portuguese or Dutch. Phonological adaptation and shift of meaning may have happen when the words were loaned from French to Dutch language or later, when adapted from Dutch into Indonesian language. The data analysed in this article may help teachers of French as a Foreign Language in Indonesia, as well as teachers of Indonesian as a Foreign Language in French-speaking countries, to predict which words will be immediately recognized by their students, and when they should pay extra-attention to faux-amis (cognates whose meanings differ).
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Rodríguez, Carmen Lucena, Javier Mula, Jesús Domingo Segovia y Cristina Cruz-González. "The effects of covid-19 on science education: A thematic review of ınternational research". Journal of Turkish Science Education 18, Covid-19 Special Issue (31 de agosto de 2021): 26–45. http://dx.doi.org/10.36681/tused.2021.70.
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The health emergency caused by the COVID-19 pandemic has transformed and decisively affected the entire education system, which has resulted in an urgent need to adapt it to an online scenario. Science education is an area that has been highly affected by and, as a consequence, science teachers were forced to make an extra effort to create virtual learning environments accessible for all students. This study offers a systematic review to synthesize how the COVID-19 pandemic has influenced science teachers’ educational practices and adaptations. To this end, Web of Science, ERIC and Scopus databases used to explore the virtual educational practices, e.g., teaching-learning processes, during the pandemic. The purpose of this study is to analyze the main bibliographic characteristics of the collected literature (research purpose, methodological design, geographical and temporal distribution, central themes) via thematic analysis. The findings offered a synthesis of studies that explain innovative practices, tools, and strategies that were very useful for teachers and students in the STEM area. We believe that future lines of research should be oriented towards broadening the analysis of different pedagogical approaches developed in the teaching of STEM areas during the health crisis by COVID-19. This could be useful for guiding professional and educational actions.
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Tevaearai, Mueller, Chastonay, Favre, Ravussin, Eckert, Vogt, Delabays, von Segesser y Stumpe. "Coronary Bypass via a Mini-Thoracotomy: Advantages Become Evident with the Growing Experience of the Medical Team". Swiss Surgery 7, n.º 1 (1 de febrero de 2001): 16–19. http://dx.doi.org/10.1024/1023-9332.7.1.16.
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But du travail: La chirurgie de revascularisation myocardique minimale invasive est fondamentalement différente de la méthode classique sous circulation extra-corporelle (CEC). Elle oblige à de nombreuses adaptations tant opératoire, qu'anesthésiologique et post-opératoire. Nous évaluons l'effet éventuel d'une phase d'apprentissage sur les résultats à court terme de cette nouvelle technique. Méthode: Nous présentons notre expérience de 20 patients ayant bénéficiés de cette approche de juillet 1997 à février 1999, en comparant du point de vue chirurgical et post-opératoire, 2 collectifs successifs de 10 patients chacun (groupe 1: 8H2F; 59.6 +/- 13.8 ans) aux 10 derniers (groupe 2: 8H/2F; 63.2 +/- 6.1 ans). Discussion: La progression est remarquable du point de vue opératoire et post-opératoire: Le temps de clampage de l'IVA est passé de 28.5 +/- 2.4 min. à 22.2 +/- 1.8 min. (p < 0.05) et le temps opératoire est passé de 125 +/- 4 à 97 +/- 5 min. (p < 0.005). La morbidité post-opératoire a régressé avec un taux de fibrillation auriculsire (FA) passant de 4/10 pour le groupe 1 à 1/10 pour le groupe 2, et un taux de pneumonie passant de 3/10 à 0. Le séjour aux soins intensifs est passé de 2.3 +/- 0.3 jours à 1.4 +/- 0.2 jours (p < 0.05). Le séjour hospitalier post-opératoire est passé de 8.5 +/- 0.9 à 4.7 +/- 0.5 jours (p < 0.005). Conclusion: Il existe clairement une phase d'apprentissage en chirurgie cardiaque mini-invasive. Cette période passée, les avantages immédiats de la technique apparaissent notamment par une diminution du temps opératoire, du séjour aux soins intensifs et du séjour post-opératoire.
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McCann, Katelyn J., Manoj Yadav, Mohammadali E. Alishahedani, Alexandra F. Freeman y Ian A. Myles. "Differential responses to folic acid in an established keloid fibroblast cell line are mediated by JAK1/2 and STAT3". PLOS ONE 16, n.º 3 (4 de marzo de 2021): e0248011. http://dx.doi.org/10.1371/journal.pone.0248011.
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Keloids are a type of disordered scar formation which not only show heterogeneity between individuals and within the scar itself, but also share common features of hyperproliferation, abnormal extra-cellular matrix deposition and degradation, as well as altered expression of the molecular markers of wound healing. Numerous reports have established that cells from keloid scars display Warburg metabolism—a form of JAK2/STAT3-induced metabolic adaptation typical of rapidly dividing cells in which glycolysis becomes the predominant source of ATP over oxidative phosphorylation (OxPhos). Using the JAK1/2 inhibitor ruxolitinib, along with cells from patients with STAT3 loss of function (STA3 LOF; autosomal dominant hyper IgE syndrome) we examined the role of JAK/STAT signaling in the hyperproliferation and metabolic dysregulation seen in keloid fibroblasts. Although ruxolitinib inhibited hyperactivity in the scratch assay in keloid fibroblasts, it paradoxically exacerbated the hyper-glycolytic state, possibly by further limiting OxPhos via alterations in mitochondrial phosphorylated STAT3 (pSTAT3Ser727). In healthy volunteer fibroblasts, folic acid exposure recapitulated the exaggerated closure and hyper-glycolytic state of keloid fibroblasts through JAK1/2- and STAT3-dependent pathways. Although additional studies are needed before extrapolating from a representative cell line to keloids writ large, our results provide novel insights into the metabolic consequences of STAT3 dysfunction, suggest a possible role for folate metabolism in the pathogenesis of keloid scars, and offer in vitro pre-clinical data supporting considerations of clinical trials for ruxolitinib in keloid disorder.
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Dai, Zheng, Heting Fu, Yufeng Zhang, Jing Zeng, Bing Tang y Xiao-Feng Tang. "Insights into the Maturation of Hyperthermophilic Pyrolysin and the Roles of Its N-Terminal Propeptide and Long C-Terminal Extension". Applied and Environmental Microbiology 78, n.º 12 (13 de abril de 2012): 4233–41. http://dx.doi.org/10.1128/aem.00548-12.
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ABSTRACTPyrolysin-like proteases from hyperthermophiles are characterized by large insertions and long C-terminal extensions (CTEs). However, little is known about the roles of these extra structural elements or the maturation of these enzymes. Here, the recombinant proform ofPyrococcus furiosuspyrolysin (Pls) and several N- and C-terminal deletion mutants were successfully expressed inEscherichia coli. Pls was converted to mature enzyme (mPls) at high temperatures via autoprocessing of both the N-terminal propeptide and the C-terminal portion of the long CTE, indicating that the long CTE actually consists of the C-terminal propeptide and the C-terminal extension (CTEm), which remains attached to the catalytic domain in the mature enzyme. Although the N-terminal propeptide deletion mutant PlsΔN displayed weak activity, this mutant was highly susceptible to autoproteolysis and/or thermogenic hydrolysis. The N-terminal propeptide acts as an intramolecular chaperone to assist the folding of pyrolysin into its thermostable conformation. In contrast, the C-terminal propeptide deletion mutant PlsΔC199 was converted to a mature form (mPlsΔC199), which is the same size as but less stable than mPls, suggesting that the C-terminal propeptide is not essential for folding but is important for pyrolysin hyperthermostability. Characterization of the full-length (mPls) and CTEm deletion (mPlsΔC740) mature forms demonstrated that CTEm not only confers additional stability to the enzyme but also improves its catalytic efficiency for both proteineous and small synthetic peptide substrates. Our results may provide important clues about the roles of propeptides and CTEs in the adaptation of hyperthermophilic proteases to hyperthermal environments.
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Mogk, Axel, Tobias Haslberger, Peter Tessarz y Bernd Bukau. "Common and specific mechanisms of AAA+ proteins involved in protein quality control". Biochemical Society Transactions 36, n.º 1 (22 de enero de 2008): 120–25. http://dx.doi.org/10.1042/bst0360120.
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A protein quality control system, consisting of molecular chaperones and proteases, controls the folding status of proteins and mediates the refolding or degradation of misfolded proteins. Ring-forming AAA+ (ATPase associated with various cellular activities) proteins play crucial roles in both processes by co-operating with either peptidases or chaperone systems. Peptidase-associated AAA+ proteins bind substrates and thread them through their axial channel into the attached proteolytic chambers for degradation. In contrast, the AAA+ protein ClpB evolved independently from an interacting peptidase and co-operates with a cognate Hsp70 (heat-shock protein 70) chaperone system to solubilize and refold aggregated proteins. The activity of this bi-chaperone system is crucial for the survival of bacteria, yeast and plants during severe stress conditions. Hsp70 acts at initial stages of the disaggregation process, enabling ClpB to extract single unfolded polypeptides from the aggregate via a threading activity. Although both classes of AAA+ proteins share a common threading activity, it is apparent that their divergent evolution translates into specific mechanisms, reflecting adaptations to their respective functions. The ClpB-specific M-domain (middle domain) represents such an extra feature that verifies ClpB as the central disaggregase in vivo. M-domains act as regulatory devices to control both ClpB ATPase activity and the Hsp70-dependent binding of aggregated proteins to the ClpB pore, thereby coupling the Hsp70 chaperone activity with the ClpB threading motor to ensure efficient protein disaggregation.
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Slater, Joanne, Rebecca McLay-Cooke, Rachel Brown y Katherine Black. "Female Recreational Exercisers at Risk for Low Energy Availability". International Journal of Sport Nutrition and Exercise Metabolism 26, n.º 5 (octubre de 2016): 421–27. http://dx.doi.org/10.1123/ijsnem.2015-0245.
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Low energy availability (LEA) describes the disruption in normal physiological function existent when insufficient energy intake is combined with exercise. To conserve energy a range of endocrine adaptations occur, impairing health and athletic performance. The prevalence of LEA has not been fully established especially among recreational exercisers. Determining recreational exercisers at risk of LEA may help to maximize prevention, early diagnosis and treatment. The design of this study was a cross-sectional online survey. One-hundred and nine female recreational exercisers, with a mean age of 23.8 (SD 6.9) years were recruited via gyms and fitness centers throughout NZ. Participants completed an online questionnaire including questions from the LEAF-Q (Low Energy Availability in Females Questionnaire). A total of 45.0% (CI, 35.4%, 54.8%) of participants were classified as “at risk“ of LEA. For every extra hour of exercise per week the odds of being at risk of LEA were 1.13 times greater (CI 1.02, 1.25, p = .016). All participants reporting previous stress fracture injuries (n = 4) were classified as at risk for LEA. Significantly more subjects participating in an individual sport were classified as at risk for LEA (69.6%, CI 24.3%, 54.8%) compared with team sports (34.8%, CI 18.7%, 40.5%) (p = .006). The high prevalence of female recreational exercisers at risk of LEA is of concern, emphasizing the importance of increasing awareness of the issue, and promoting prevention and early detection strategies, so treatment can be implemented before health is severely compromised.
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Speijer, Dave. "Being right on Q: shaping eukaryotic evolution". Biochemical Journal 473, n.º 22 (10 de noviembre de 2016): 4103–27. http://dx.doi.org/10.1042/bcj20160647.
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Reactive oxygen species (ROS) formation by mitochondria is an incompletely understood eukaryotic process. I proposed a kinetic model [BioEssays (2011) 33, 88–94] in which the ratio between electrons entering the respiratory chain via FADH2 or NADH (the F/N ratio) is a crucial determinant of ROS formation. During glucose breakdown, the ratio is low, while during fatty acid breakdown, the ratio is high (the longer the fatty acid, the higher is the ratio), leading to higher ROS levels. Thus, breakdown of (very-long-chain) fatty acids should occur without generating extra FADH2 in mitochondria. This explains peroxisome evolution. A potential ROS increase could also explain the absence of fatty acid oxidation in long-lived cells (neurons) as well as other eukaryotic adaptations, such as dynamic supercomplex formation. Effective combinations of metabolic pathways from the host and the endosymbiont (mitochondrion) allowed larger varieties of substrates (with different F/N ratios) to be oxidized, but high F/N ratios increase ROS formation. This might have led to carnitine shuttles, uncoupling proteins, and multiple antioxidant mechanisms, especially linked to fatty acid oxidation [BioEssays (2014) 36, 634–643]. Recent data regarding peroxisome evolution and their relationships with mitochondria, ROS formation by Complex I during ischaemia/reperfusion injury, and supercomplex formation adjustment to F/N ratios strongly support the model. I will further discuss the model in the light of experimental findings regarding mitochondrial ROS formation.
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Aparicio-Valdez, Luis. "La gestion empresarial en latinoamérica y su impacto en las relaciones laborales". Articles 44, n.º 1 (12 de abril de 2005): 124–48. http://dx.doi.org/10.7202/050476ar.
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Les relations du travail en Amérique Latine se caractérisent par la présence traditionnelle d'un autoritarisme étatique qui se manifeste par une intervention continuelle, une législation abondante et parfois contradictoire, ainsi que par un conflit permanent. Tout cela dans un cadre social hétérogène dans lequel les relations du travail ont depuis peu cesse d'être atomisé pour se centraliser dans les branches industrielles. Ces caractéristiques normalisent toujours les relations du travail en Amérique Latine, mais leur poids diminue chaque fois que de nouveaux facteurs, tant internes qu'externes, entrent en jeu. Les nouvelles tendances, encore embryonnaires, amplifient le caractère extra juridique de la relation employeur-travailleur, de même que l'autonomie des acteurs immédiats en relations du travail, ainsi que la faible présence d'une optique coopérative et participative. La gestion patronale a joué un rôle principal dans cette évolution, particulièrement dans les domaines nouveaux, là où l'absence de tradition a facilité l'innovation. Les multinationales et le secteur d'exportations non traditionnel constituent les meilleurs exemples. Ce résumé a pour objet de présenter ces nouvelles tendances, d'identifier les facteurs internes et externes qui les ont générés, ainsi que d'offrir une base de comparaison pour faciliter une évolution globale de l'état des relations du travail au niveau international. Facteurs internes : La gestion patronale actuelle en Amérique Latine montre qu'il y a une crise complexe chez les protagonistes des relations du travail, c'est-à-dire les travailleurs, les employeurs et l'État. D'un cote, l'augmentation inusitée des grèves locales et nationales, le caractère « illégal » de la majorité des grèves locales dues à l'échec de la négociation collective, ou encore, leur emploi comme outil de solution des conflits, et enfin, l'importante complexité des demandes constituent les principaux problèmes. La source immédiate de ceux-ci est syndicale, alors que les causes plus profondes se rencontrent, pour la majorité, en dehors du contrôle des acteurs. À cause de cette distanciation, les relations se polarisent chaque fois plus. Les relations du travail doivent ainsi en venir à se rencontrer devant un tiers, l'État, qui lui aussi, devient chaque fois plus décisif. De l'autre cote, le maintien, l'accroissement ou le changement fréquent des lois du travail ainsi que la partialité des gouvernements en place soit avec les employeurs ou les travailleurs, reflètent la continuité ou l'augmentation de l'interventionnisme étatique dans la détérioration des relations entre les parties. Les réajustements périodiques des salaires selon les changements au cout de la vie dus à l'inflation, par exemple, exigent des employeurs qu'ils réajustent subséquemment leurs politiques salariales et leurs couts divers. Les changements dans la législation imposent une adaptation de la part des employeurs. En général, l'important interventionnisme étatique ainsi que le réglementarisme limitent de manière irrationnelle le mouvement autonome des relations du travail. Cependant, autant les employeurs que les travailleurs ont exercé, ces dernières années, une force extraordinaire tendant à changer, en leur faveur, le schéma et les règles qui gouvernent les relations du travail. Tous deux ont influencé le processus politique afin de limiter le déterminisme étatique dans les deux secteurs de la propriété, publique et privée, mais aussi dans le but de forcer la réconciliation avec leur acteur rival et ceci, en accord avec la logique de leurs propres intérêts. Le solde net de ce changement a été une relative ouverture du système traditionnel des relations du travail vers des formes nouvelles de relations, comme le système d'administration des ressources humaines, la concertation sociale, la négociation par branche industrielle et la transformation du régime du travail dans le secteur public, particulièrement dans les entreprises de l'État. Facteurs externes : La crise économique que vivent pratiquement tous les pays de cette région, l'accroissement disproportionne de l'offre de travail et de ses accompagnateurs naturels comme le chômage et le travail au noir, l'intervention excessive de l'État dans l'économie, de même que son centralisme, et le défi de la concurrence internationale basé sur l'internationalisation des facteurs de production sont les changements contextuels qui ont eu un impact majeur dans les relations du travail en Amérique Latine. Ceux-ci ont exercé une influence variable aussi bien sur les facteurs internes mentionnes plus haut que sur les relations du travail elles-mêmes, de façon directe. La gestion patronale a répondu à ces divers facteurs avec une grande variété de critères et d'actions. Une des réponses a été l'adoption de systèmes d'administration du personnel en remplacement du système de relations du travail. Même si cette pratique est naissante, son développement rapide, et ceci dans les secteurs les pins modernes et les plus rentables (les multinationales en constituent l'avant-garde), lui a concédée une importance majeure ces dernières années. Le système d'administration des ressources humaines est un concept radicalement différent de celui du système traditionnel des relations du travail. Alors que le premier est centre sur la relation individuelle employeur-travailleur, le second l'est sur la relation collective employeur-syndicat. L'expérience latino-américaine montre que la tendance actuelle va vers la superposition des systèmes. Les entreprises qui furent organisées sous le système traditionnel de relations du travail continuent dans cette direction, alors que les nouvelles entreprises, particulièrement celles qui participent aux secteurs les plus modernes de l'économie, ont l'option d'essayer un ou l'autre des systèmes, ou encore l'intégration des deux. Dans le cas où le système de l'administration des ressources humaines est adopte, le raisonnement logique est de donner fréquemment des avantages non économiques aux travailleurs, afin qu'ils ne voient pas la nécessité de recourir à la syndicalisation, ou encore, dans le but de diminuer les sources de conflit. Trois types de stratégies ont été pratiques dans divers pays : a) la création d'associations professionnelles dans le champ des ressources humaines et de l'administration du personnel, avec pour objectif d'améliorer le recrutement et la promotion dans l'emploi; b) la création et le développement de mécanismes destines à motiver les travailleurs, comme les cercles de qualité, les comités mixtes travailleurs-direction de l'entreprise et les programmes d'incitation non pécuniaires; c) l'ouverture d'alternatives participatives, aussi bien dans la gestion (cogestion, cogouvernement ou codétermination), que dans les bénéfices et la propriété de l'entreprise. Cette dernière stratégie a généralement été exécutée dans des conditions de faible stabilité du travail et de faible influence de la négociation collective. La motivation du travailleur a été le centre d'attention de divers programmes crées sous l'initiative de l'employeur. Les cercles de qualité sont les plus répandus en Amérique Latine, mais des comités de productivité, des programmes de préretraite et des clubs sociaux à l'intérieur de l'entreprise ont aussi été formes. En quelques mots, l'adoption du système d'administration des ressources humaines, même si elle est récente, est déjà une réalité en Amérique Latine. Le développement et l'établissement général de ces programmes sont ici plus que de simples souhaits des acteurs sociaux. On pourrait dire qu'il leur reste à traverser le même niveau de difficultés que le développement économique des pays latino-américains.
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Fang, Yan, Qingyao Ai, Jingtao Zhan, Yiqun Liu, Xiaolong Wu y Zhao Cao. "Combining Multiple Supervision for Robust Zero-Shot Dense Retrieval". Proceedings of the AAAI Conference on Artificial Intelligence 38, n.º 16 (24 de marzo de 2024): 17994–8002. http://dx.doi.org/10.1609/aaai.v38i16.29755.
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Recently, dense retrieval (DR) models, which represent queries and documents with fixed-width vectors and retrieve relevant ones via nearest neighbor search, have drawn increasing attention from the IR community. However, previous studies have shown that the effectiveness of DR critically relies on sufficient training signals, which leads to severe performance degradation when applied in out-of-domain scenarios, where large-scale training data are usually unavailable. To solve this problem, existing studies adopt a data-augmentation-plus-joint-training paradigm to construct weak/pseudo supervisions on the target domain and combine them with the large-scale human annotated data on the source domain to train the DR models. However, they don't explicitly distinguish the data and the supervision signals in the training process and simply assume that the DR models are mighty enough to capture and memorize different domain knowledge and relevance matching patterns without guidance, which, as shown in this paper, is not true. Based on this observation, we propose a Robust Multi-Supervision Combining strategy (RMSC) that decouples the domain and supervision signals by explicitly telling the DR models how the domain data and supervision signals are combined in the training data with specially designed soft tokens. With the extra soft tokens to store the domain-specific and supervision-specific knowledge, RMSC allows the DR models to conduct retrieval based on human-like relevance matching patterns and target-specific language distribution on the target domain without human annotations. Extensive experiments on zero-shot DR benchmarks show that RMSC significantly improves the ranking performance on the target domain compared to strong DR baselines and domain adaptation methods, while being stable during training and can be combined with query generation or second-stage pre-training.
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Silva, V. L. S., M. A. Cardoso, D. F. B. Oliveira y R. J. de Moraes. "Stochastic optimization strategies applied to the OLYMPUS benchmark". Computational Geosciences 24, n.º 6 (21 de octubre de 2019): 1943–58. http://dx.doi.org/10.1007/s10596-019-09854-3.
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AbstractIn this work, we discuss the application of stochastic optimization approaches to the OLYMPUS case, a benchmark challenge which seeks the evaluation of different techniques applied to well control and field development optimization. For that matter, three exercises have been proposed, namely, (i) well control optimization; (ii) field development optimization; and (iii) joint optimization. All applications were performed considering the so-called OLYMPUS case, a synthetic reservoir model with geological uncertainty provided by TNO (Fonseca 2018). Firstly, in the well control exercise, we successfully applied an ensemble-based approximate gradient method in a robust optimization formulation. Secondly, we solve the field development exercise using a genetic algorithm framework designed with special features for the problem of interest. Finally, in order to evaluate further gains, a sequential optimization approach was employed, in which we run one more well control optimization based on the optimal well locations. Even though we utilize relatively well-known techniques in our studies, we describe the necessary adaptations to the algorithms that enable their successful applications to real-life scenarios. Significant gains in the expected net present value are obtained: in exercise (i) a gain of 7% with respect to reactive control; for exercise (ii) a gain of 660% with respect to a initial well placement based on an engineering approach; and for (iii) an extra gain of 3% due to an additional well control optimization after the well placement optimization. All these gains are obtained with an affordable computational cost via the extensive utilization of high-performance computing (HPC) infrastructure. We also apply a scenario reduction technique to exercise (i), with similar gains obtained in the full ensemble optimization, however, with substantially inferior computational cost. In conclusion, we demonstrate how the state-of-the-art optimization technology available in the model-based reservoir management literature can be successfully applied to field development optimization via the conscious utilization of HPC facilities.
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Vosko, Andrew M., Megan H. Hagenauer, Daniel L. Hummer y Theresa M. Lee. "Period gene expression in the diurnal degu (Octodon degus) differs from the nocturnal laboratory rat (Rattus norvegicus)". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 296, n.º 2 (febrero de 2009): R353—R361. http://dx.doi.org/10.1152/ajpregu.90392.2008.
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Recent data suggest that both nocturnal and diurnal mammals generate circadian rhythms using similarly phased feedback loops involving Period genes in the suprachiasmatic nuclei (SCN) of the hypothalamus. These molecular oscillations also exist in the brain outside of the SCN, but the relationship between SCN and extra-SCN oscillations is unclear. We hypothesized that a comparison of “diurnal” and “nocturnal” central nervous system Per rhythms would uncover differences in the underlying circadian mechanisms between these two chronotypes. Therefore, this study compared the 24-h oscillatory patterns of Per1 and Per2 mRNA in the SCN and putative striatum and cortex of Octodon degus (degu), a diurnal hystricognath rodent, with those of the nocturnal laboratory rat, Rattus norvegicus. The brains of adult male degus and rats were collected at 2-h intervals across 24 h in entrained light-dark and constant darkness conditions, and sections were analyzed via in situ hybridization. In the SCN, degu Per1 and Per2 hybridization signal exhibited 24-h oscillatory patterns similar in phasing to those seen in other rodents, with peaks occurring during the light period and troughs during the dark period. However, Per1 remained elevated for five fewer hours in the degu than in the rat, and Per2 remained elevated for two fewer hours in the degu. In brain areas outside of the SCN, the phase of Per2 hybridization signal rhythms in the degu were 180° out of phase with those found in the rat, and Per1 hybridization signal lacked significant rhythmicity. These results suggest that, while certain basic components of the transcriptional-translational feedback loop generating circadian rhythms are similar in diurnal and nocturnal mammals, there are variations that may reflect adaptations to circadian niche.
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Ansbro, Éimhín, Sylvia Garry, Veena Karir, Amulya Reddy, Kiran Jobanputra, Taissir Fardous y Zia Sadique. "Delivering a primary-level non-communicable disease programme for Syrian refugees and the host population in Jordan: a descriptive costing study". Health Policy and Planning 35, n.º 8 (4 de julio de 2020): 931–40. http://dx.doi.org/10.1093/heapol/czaa050.
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Abstract The Syrian conflict has caused enormous displacement of a population with a high non-communicable disease (NCD) burden into surrounding countries, overwhelming health systems’ NCD care capacity. Médecins sans Frontières (MSF) developed a primary-level NCD programme, serving Syrian refugees and the host population in Irbid, Jordan, to assist the response. Cost data, which are currently lacking, may support programme adaptation and system scale up of such NCD services. This descriptive costing study from the provider perspective explored financial costs of the MSF NCD programme. We estimated annual total, per patient and per consultation costs for 2015–17 using a combined ingredients-based and step-down allocation approach. Data were collected via programme budgets, facility records, direct observation and informal interviews. Scenario analyses explored the impact of varying procurement processes, consultation frequency and task sharing. Total annual programme cost ranged from 4 to 6 million International Dollars (INT$), increasing annually from INT$4 206 481 (2015) to INT$6 739 438 (2017), with costs driven mainly by human resources and drugs. Per patient per year cost increased 23% from INT$1424 (2015) to 1751 (2016), and by 9% to 1904 (2017), while cost per consultation increased from INT$209 to 253 (2015–17). Annual cost increases reflected growing patient load and increasing service complexity throughout 2015–17. A scenario importing all medications cut total costs by 31%, while negotiating importation of high-cost items offered 13% savings. Leveraging pooled procurement for local purchasing could save 20%. Staff costs were more sensitive to reducing clinical review frequency than to task sharing review to nurses. Over 1000 extra patients could be enrolled without additional staffing cost if care delivery was restructured. Total costs significantly exceeded costs reported for NCD care in low-income humanitarian contexts. Efficiencies gained by revising procurement and/or restructuring consultation models could confer cost savings or facilitate cohort expansion. Cost effectiveness studies of adapted models are recommended.
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Blaustein, M. P. "Physiological effects of endogenous ouabain: control of intracellular Ca2+ stores and cell responsiveness". American Journal of Physiology-Cell Physiology 264, n.º 6 (1 de junio de 1993): C1367—C1387. http://dx.doi.org/10.1152/ajpcell.1993.264.6.c1367.
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Ouabain is a well-known compound but a newly discovered adrenal cortical hormone that plays a role in cell Na+ regulation and in whole body salt and water balance. Ouabain may also be a paracrine hormone and may be secreted by some central nervous system neurons as well as by other types of cells. This article focuses on the cellular mechanisms that underlie the physiological (and pathophysiological) effects of ouabain. Ouabain directly inhibits the plasmalemmal Na+ pump in a variety of cell types. Low ouabain concentrations cause, in the steady state, a modest rise in the cytosolic Na+ concentration but only a minimal decline in membrane potential. All Na+ gradient-dependent processes may thereby be affected, albeit to only a small extent. Most important, however, is the secondary redistribution of Ca2+, mediated by Na(+)-Ca2+ exchange, that should slightly increase the cytosolic free Ca2+ concentration ([Ca2+]cyt). As a result of Ca2+ sequestration in intracellular stores [the endoplasmic and/or sarcoplasmic reticulum (ER/SR)], however, a new steady state is achieved with a slightly increased [Ca2+]cyt but a substantially augmented Ca2+ store; thus the ER/SR effectively acts as a Ca2+ amplifier. This extra stored Ca2+ is then available for mobilization whenever the cells are activated. Cytosolic Ca2+ is a key signaling mechanism in virtually all cells: it controls numerous physiological processes such as contraction, secretion, and excitability. Thus ouabain may modulate cell responsiveness via its influence on ER/SR Ca2+ stores. With these principles in mind, we examine evidence that endogenous ouabain may play a role in numerous physiological and pathophysiological processes associated with altered fluid and electrolyte metabolism and deviations from the normal blood pressure-blood volume relationship. We discuss the possible participation of ouabain in the regulation of vascular tone and then consider the putative role of ouabain in several forms of hypertension, congestive heart failure, thyroid and adrenocortical dysfunction, and diabetes mellitus, as well as in the adaptation to high altitude.
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Yazdanparast, Atefeh, Mathew Joseph y Fernanda Muniz. "Consumer based brand equity in the 21st century: an examination of the role of social media marketing". Young Consumers 17, n.º 3 (15 de agosto de 2016): 243–55. http://dx.doi.org/10.1108/yc-03-2016-00590.
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Purpose The present research investigates the influence of brand-based social media marketing (SMM) activities on metrics of consumer-based brand equity (CBBE). Specifically, the study examines the role of consumer-brand social media experiences on attitude toward SMM activities of brands and its consequent impact on brand perceptions. Design/methodology/approach Paper-and-pencil surveys were administered to undergraduate students in a Southwestern university in exchange for extra credit. Survey questions were adapted from previously validated scales, and measurement adaptations were minimal and only related to the context of questions to assure their relevance with the context of this study. Bi-variate correlation, bootstrapping technique, Sobel test, ANOVA and linear regression were used to test the hypotheses. Findings The results indicate that brand-based SMM is essential in impacting consumers’ attitudes toward brands and consequently, CBBE reflected via perceived value for the cost, perceived uniqueness and the willingness to pay a price premium for a brand. Additionally, the main reason for individuals to use social media impacts their attitudes toward and receptiveness of SMM activities of brands. Research limitations/implications This study used a sample of college students to address the research questions. Considering the higher adoption rate and interest in social media among younger consumer groups, the results may not be representative of the entire population. Much of the existing research on social media, however, has focused on undergraduate college students and is primarily based on studies utilizing the similar research population. Originality/value The present research is one of the few studies that empirically examine the impact of consumer-brand interactions/experiences on consumers’ attitudes toward SMM activities of brands, as well as brand-related knowledge and perceptions as reflected by CBBE. The results indicate that the CBBE model of the twenty-first century should incorporate the role of brand-based SMM activities as facilitators of brand knowledge (i.e. brand awareness and brand image) by reinforcing or even shaping important brand-based associations.
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Warzecha, Tomasz, Jan Bocianowski, Marzena Warchoł, Roman Bathelt, Agnieszka Sutkowska y Edyta Skrzypek. "Effect of Soil Drought Stress on Selected Biochemical Parameters and Yield of Oat × Maize Addition (OMA) Lines". International Journal of Molecular Sciences 24, n.º 18 (9 de septiembre de 2023): 13905. http://dx.doi.org/10.3390/ijms241813905.
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Plant growth and the process of yield formation in crops are moderated by surrounding conditions, as well as the interaction of the genetic background of plants and the environment. In the last two decades, significant climatic changes have been observed, generating unfavorable and harmful impacts on plant development. Drought stress can be considered one of the most dangerous environmental factors affecting the life cycle of plants, reducing biomass production and, finally, the yield. Plants can respond to water deficit in a wide range, which depends on the species, genetic variability within the species, the plant’s ontogenesis stage, the intensity of the stress, and other potential stress factors. In plants, it is possible to observe hybrids between different taxa that certain traits adopted to tolerate stress conditions better than the parent plants. Oat × maize addition (OMA) plants are good examples of hybrids generated via wide crossing. They can exhibit morphological, physiological, and biochemical variations implemented by the occurrence of extra chromosomes of maize, as well as the interaction of maize and oat chromatin. The initial goal of the study was to identify OMA lines among plants produced by wide crossing with maize. The main goal was to investigate differences in OMA lines according to the Excised Leaf Water Loss (ELWL) test and to identify specific biochemical changes and agronomic traits under optimal water conditions and soil drought. Additionally, detection of any potential alterations that are stable in F2 and F3 generations. The aforementioned outcomes were the basis for the selection of OMA lines that tolerate growth in an environment with limited water availability. The molecular analysis indicated 12.5% OMA lines among all tested descendants of wide oat-maize crossing. The OMA lines significantly differ according to ELWL test results, which implies some anatomical and physiological adaptation to water loss from tissues. On the first day of drought, plants possessed 34% more soluble sugars compared to control plants. On the fourteen day of drought, the amount of soluble sugars was reduced by 41.2%. A significant increase of phenolic compounds was observed in the fourteen day of drought, an average of 6%, even up to 57% in line 9. Soil drought substantially reduced stem biomass, grains number, and mass per plant. Lower water loss revealed by results of the ELWL test correlated with the high yield of OMA lines. Phenolic compound content might be used as a biochemical indicator of plant drought tolerance since there was a significant correlation with the high yield of plants subjected to soil drought.
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Rudkouskaya, Alena, Cassandra L. Roberge, Lauren Elder, Kailie Matteson, David T. Corr y Margarida Barroso. "Abstract P4-01-12: Short-term trastuzumab treatment increases oncogenic fitness in HER2 overexpressing breast cancer models". Cancer Research 82, n.º 4_Supplement (15 de febrero de 2022): P4–01–12—P4–01–12. http://dx.doi.org/10.1158/1538-7445.sabcs21-p4-01-12.
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Abstract Overexpression of Human EGF Receptor 2 (HER2) is found in up to 20% of primary invasive breast cancers and is a marker of aggressive metastatic disease and poor prognosis. HER2 is a member of the transmembrane tyrosine kinase receptors family which includes EGFR (HER1), HER3 and HER4. Phosphorylation of tyrosine residues in the cytoplasmic domain upon homo- or heterodimerization results in stimulation of cellular proliferation, migration, angiogenesis, and inhibition of apoptosis. HER2 is deemed a preferred heterodimer partner and presents an excellent target for personalized medicine. Anti-HER2 monoclonal antibody trastuzumab (TZM) has been used in the clinic over the last decades and it is considered as one of the most successful targeted anti-cancer therapies. However, a large fraction of eligible patients displays either primary or acquired resistance to TZM treatment. In this study, we report that even relatively short 24h TZM exposure (TZM-priming) of AU565 HER2-overexpressing breast cancer cells results in rapid and profound alterations in HER receptors’ expression level and signaling, as well as upregulation of markers associated with drug resistance. We provide several lines of evidence to support this claim: Firstly, Western blot analysis of both monolayer AU565 cells incubated in the presence or absence of 20 μg/mL TZM (TZM priming) or human IgG (control), as well as of liquid overlay AU565 spheroids generated from TZM-primed or control cells, consistently shows significant increase of HER3 and pHER2 levels in the TZM-primed samples. Secondly, immunofluorescent analysis strongly indicates that TZM priming substantially upregulates HER3 and pHER2 levels both in 2D and 3D (spheroids) models. Importantly, this process is accompanied by rearrangement of endocytic markers Rab4, CD63, Sorl1 as well as Extra domain B fibronectin, found at the cells’ surface together with HER2 and HER3 upon TZM priming. A similar trend was also found in HER2-overexpressing ovarian cancer cells SKOV-3 subjected to short-term TZM treatment. Furthermore, spheroids made with TZM-primed AU565 cells display significantly faster cell proliferation compared to IgG-primed or untreated control counterparts, as measured via optical coherent tomography imaging and Imaris 3D rendering software. Finally, tumor xenografts implanted in athymic nude mice using TZM-primed AU565 cells display continuous growth in contrast to those generated from untreated cells. These results suggest that short-term TZM treatment may inadvertently increase oncogenic fitness via adaptation to TZM-HER2 cellular binding and subsequent disruption of dimerization and signaling. These results are consistent with reports indicating that regional HER2 expression heterogeneity appears to increase with TZM treatment. Moreover, these observations are especially concerning because radiolabeled TZM probes have been employed in PET imaging in HER2+ cancer patients. In summary, our results suggest that short-term TZM treatment may result in priming and selection for more aggressive cancer phenotype. Citation Format: Alena Rudkouskaya, Cassandra L Roberge, Lauren Elder, Kailie Matteson, David T Corr, Margarida Barroso. Short-term trastuzumab treatment increases oncogenic fitness in HER2 overexpressing breast cancer models [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-01-12.
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Presley, Jennifer. "Artificial Lift: Adapting to Change". Journal of Petroleum Technology 74, n.º 10 (1 de octubre de 2022): 22–26. http://dx.doi.org/10.2118/1022-0022-jpt.
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_ Humans and oil are alike in that the inner will to move from a comfortable spot—be it a sofa or a shale pore—often requires the application of outer motivation. It could be the hunger pangs prompting a reach for a donut or the pesky roommate—natural gas—lifting the hefty crude bead on its way to the surface in response to a pressure differential. So, what is a human to do when the oil needs a little extra convincing to leave its sofa? Artificial lift has long provided the swift kick needed to get and keep oil moving in conventional resources. Its story in unconventional resources is one of countless hours spent in the field figuring out that what works in one basin may not necessarily work in another and that what works today to economically lift oil to the surface will change over the life of the well. In this first part of a two-part series, we look at how the artificial-lift sector has adapted to producing unconventional resources. The second part of the series to publish in November will crack open the lift toolbox to take a deeper look at the techniques and technologies under development or new to the market. Steep Learning Curve While the life cycle of conventional oil and gas development is well documented, the rush of unconventional wells that kicked off in 2009 brought with it a whole slew of new challenges, like highly tortuous wellbores and solids production, spurring a greater appreciation for the intricacies of field development. “There was a steep learning curve in the early stages of producing from unconventional reservoirs. As operators continue to develop these reservoirs and push the envelope by drilling longer laterals with more-complex deviation profiles, artificial lift must keep adapting,” said Thomas Anderson, vice president of rod-lift solutions and PCS Ferguson at Champion X. “What worked last week needs to be tweaked to perform even better to handle the challenges we’ll face next week. It’s a constant evolution and we’re continually working to evolve our fit-for-purpose technologies, processes, and services to meet tomorrow’s challenges.” The remarkable growth of the US shale industry over the past 13 years has been, in part, built on the foundation of conventional oil and gas techniques and technologies. “Existing lift methods have been redefined based on newer production challenges not present in traditional vertical wells. Well geometry, landing depth, tight casing size, longer lateral draining higher production rates, and increased oil/gas rate are just a few of the new challenges in unconventional wells,” said Humberto Machado, global product line director for artificial lift at Weatherford. “The lesson learned here is the integrated planning and the development of an artificial-lift strategy that allows scalability, rapid deployment, robust and simple to operate, minimal infrastructure, and ability to match decline curve. This requires significant trial-and-error efforts to develop best practices, and operational guidelines to enhance overall system reliability,” he added. This redefinition, along with a little adaptation, and a whole lot of experimentation has developed a new toolbox unique to its role in the production process.
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Guo, Lei, Jia Li, Hongxiang Zeng, Anna Guzman, Tingting Li, Minjung Lee, Yubin Zhou et al. "A Combination Strategy Targeting Enhancer Plasticity Exerts Synergistic Lethality Against Beti-Resistant Leukemia Cells". Blood 134, Supplement_1 (13 de noviembre de 2019): 5053. http://dx.doi.org/10.1182/blood-2019-130586.
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Primary and acquired drug resistance is a major challenge to achieving optimized clinical outcomes during cancer treatment which can arise from transcription reactivation, bypass and alteration during anticancer treatment [1-3]. Epigenetic dysregulation is emerging as a crucial component involved in drug resistance. Transcriptional adaptation during drug treatment is often mediated by inducible histone modifications, especially histone H3 lysine 27 acetylation (H3K27ac) at the distal enhancer elements, thus activating the transcription of drug resistance-associated genes [4-6]. BRD4 (bromodomain-containing protein 4), a member of the bromodomain and extra-terminal domain (BET) family, acts as a chromatin reader to regulate transcription by linking histone acetylation and core components of the transcriptional apparatus [7]. BET inhibitors (BETi), as exemplified by JQ1 and I-BET151, have been shown to suppress the growth of multiple types of tumor both in vitro and in vivo [8]. However, drug resistance associated with BETi becomes one of the major hurdles hampering the clinical applications of these promising drug candidates [8, 9]. Using BET inhibitor (BETi) resistant leukemia cells as a model system, we demonstrated herein that genome-wide enhancer remodeling played a pivotal role in driving therapeutic resistance via compensational re-expression of pro-survival genes. Capitalizing on CRISPR interference, we identified the second intron of IncRNA, PVT1, as a unique bona fidegained enhancer that restored MYCtranscription independent of BRD4 recruitment. A combined BETi and CDK7 inhibitor treatment abolished MYC transcription by impeding RNAPII loading without affecting PVT1-mediated chromatin looping at the MYClocus in BETi-resistant leukemia cells. Furthermore, recipient mice transferred with BETi-resistant murine MLL-AF9 AML cells receiving the combination treatment showed the most effective therapeutic outcomes, as characterized by prolonged overall survival and reduced tumor burdens in the spleen and bone marrow. Together, our findings have established the feasibility of targeting enhancer plasticity to overcome drug resistance associated with epigenetic therapies. References 1. Mansoori, B., et al., The Different Mechanisms of Cancer Drug Resistance: A Brief Review.Adv Pharm Bull, 2017. 7(3): p. 339-348. 2. Konieczkowski, D.J., C.M. Johannessen, and L.A. Garraway, A Convergence-Based Framework for Cancer Drug Resistance.Cancer Cell, 2018. 33(5): p. 801-815. 3. Holohan, C., et al., Cancer drug resistance: an evolving paradigm.Nat Rev Cancer, 2013. 13(10): p. 714-26. 4. Zanconato, F., et al., Transcriptional addiction in cancer cells is mediated by YAP/TAZ through BRD4.Nat Med, 2018. 24(10): p. 1599-1610. 5. Takeda, D.Y., et al., A Somatically Acquired Enhancer of the Androgen Receptor Is a Noncoding Driver in Advanced Prostate Cancer.Cell, 2018. 174(2): p. 422-432 e13. 6. Chen, X., et al., A novel enhancer regulates MGMT expression and promotes temozolomide resistance in glioblastoma.Nat Commun, 2018. 9(1): p. 2949. 7. Jang, M.K., et al., The bromodomain protein Brd4 is a positive regulatory component of P-TEFb and stimulates RNA polymerase II-dependent transcription.Mol Cell, 2005. 19(4): p. 523-34. 8. Andrieu, G., A.C. Belkina, and G.V. Denis, Clinical trials for BET inhibitors run ahead of the science.Drug Discov Today Technol, 2016. 19: p. 45-50. 9. Pervaiz, M., P. Mishra, and S. Gunther,Bromodomain Drug Discovery - the Past, the Present, and the Future.Chem Rec, 2018. 18(12): p. 1808-1817. Disclosures No relevant conflicts of interest to declare.
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Hamdi, Amel, Tariq Roshan, Alex Sheftel y Prem Ponka. "Further Elucidation of the Mechanism of Iron Transport Form Plasma Transferrin to Mitochondrial Ferrochelatase: Further Evidence for the “Kiss and Run” Hypothesis". Blood 124, n.º 21 (6 de diciembre de 2014): 4023. http://dx.doi.org/10.1182/blood.v124.21.4023.4023.
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Abstract Normal hemoglobinization of immature red blood cells (RBC) requires iron (Fe) uptake from transferrin (Tf), mediated by Tf receptors (TfR). Following the binding of Fe(III)2-Tf to TfR on the erythroid cell membrane, the Tf-TfR complexes are internalized via endocytosis, following which Fe is released from Tf by a process involving endosomal acidification and reduction by Steap3. Fe2+ is then transported across the endosomal membrane by the divalent metal transporter 1 (DMT1). Unfortunately, the post-endosomal path of Fe within cells remains elusive or is, at best, controversial. It has been commonly accepted that a low molecular weight intermediate chaperones Fe in transit from endosomes to mitochondria and other sites of utilization; however, this much sought Fe binding intermediate has never been identified. In erythroid cells, more than 90% of Fe has to enter mitochondria where ferrochelatase, the final enzyme in the heme biosynthetic pathway that inserts Fe2+ into protoporphyrin IX, resides. Indeed, strong evidence exists for specific targeting of Fe toward mitochondria in developing red blood cells in which Fe acquired from Tf continues to flow into mitochondria even when the synthesis of protoporphyrin IX is suppressed. Thus, it has been hypothesized (Ponka P. Blood 89:1, 1997) that, in hemoglobin-producing cells, there is a direct relaying of iron from the endosomal machinery to that of the mitochondria. Numerous reports from our laboratory support this hypothesis: 1) Iron acquired from Tf accumulates in mitochondria even when the synthesis of protoporphyrin IX is inhibited (Richardson et al. Blood 87:3477,1996); 2) Endosome mobility is essential for the efficient incorporation of 59Fe from 59Fe-Tf-labeled endosomes into heme (Zhang et al. Blood 105:368, 2005) and, 3) Confocal laser microscopy shows that in reticulocytes, endosomes continuously traverse the cytosol and touch mitochondria (Sheftel et al. Blood 110: 125, 2007). Based on this, we propose that erythroid precursors have special adaptations that facilitate the high rate of iron transport from endosomes to mitochondria to meet the exceptionally high demand for heme synthesis. Our lab has previously shown, using 3D live confocal imaging, that the iron delivery pathway in developing RBC involves a transient interaction of endosomes with mitochondria. To further demonstrate the interaction of these organelles, we used a novel method based on flow cytometry analyses (flow sub-cytometry) of lysates obtained from reticulocytes with fluorescently labeled endosomes (Alexa Green Transferrin) and mitochondria (MitoTracker Deep Red). Using this strategy, we have identified three distinct populations: endosomes, mitochondria, and a population double-labeled with both fluorescent markers representing endosomes interacting with mitochondria. This strategy has been used in studies on reticulocytes and erythroblasts subjected to various experimental conditions. In this study, we intended to identify molecular partners involved in the endosme-mitochondria interaction. Using co-immunoprecipitation and pull-down strategies, we attempted to recognize proteins interacting with the extra-endosomal (intracellular) loops of DMT1, which may be involved in interactions with mitochondria. The co-immunoprecipitated proteins were separated based on their molecular weights, stained using Coomassie and/or Silver gel and identified by mass spectrometry and western blotting. Using these strategies, we co-immunoprecipitated (from MEL cells and reticulocytes lysates) proteins that were pulled down with DMT1. Using this approach, we have identified the voltage-dependent anion channel (VDAC), which is located at the outer membrane of the mitochondria (Graham, et al. Curr Top Dev Biol. 59: 87, 2004) as one of DMT1 interacting partners using western blotting and specific antibodies against VDAC. These results indicate the physical contact between endosomes and mitochondria. In addition, to define the possible role of DMT1-VDAC interactions in mediating iron uptake, we used a siRNA approach to silence VDAC expression in MEL cells and then measured 59Fe incorporation into heme. These studies revealed decreased 59Fe incorporation into MEL cells with silenced VDAC. Our findings provide a strong support for the hypothesis that this outer-membrane mitochondrial protein is involved in the interaction with endosomes. Disclosures No relevant conflicts of interest to declare.
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Graham, Steve, Silza Ahumada, Gerardo Bañales, Aníbal Puente, Marcela Guajardo y Ignacio Muñoz. "Intermediate-Grade Teachers’ Adaptations for Weaker Writers: A National Survey in Urban Schools in Chile". Journal of Learning Disabilities, 18 de julio de 2020, 002221942094179. http://dx.doi.org/10.1177/0022219420941795.
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Two hundred fifty-four intermediate-grade teachers (88% female) in urban public schools in Chile indicated how frequently they made writing instructional adaptations for their weakest writers, which included students with learning and other disabilities. A majority of teachers reported making the following adaptations for their weakest writers at least once a week: individual tutoring, assistance from a peer when writing, and extra instruction in grammar/spelling, planning/revising, handwriting, sentence construction, and text structure. On a monthly basis or more often, a majority of teachers reported they provided weaker writers with choice about writing assignments, the opportunity to complete an alternative writing assignment, and extra writing instruction via computer technology. How often an adaptation was applied did not differ by grade. The perceived adequacy of teacher undergraduate preparation to teach writing, their efficacy to teach writing, and the proportion of students with disability in their classes each made a unique and statistically significant contribution to predicting how frequently teachers applied adaptations for their weakest writers. The Chilean teachers in this study reportedly made adaptations for weaker writers in their class more often than teachers in studies conducted in other countries, including the United States.
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Sanford, Natalie, Mary Lavelle, Ola Markiewicz, Gabriel Reedy, Anne Marie Rafferty, Ara Darzi y Janet E. Anderson. "Understanding complex work using an extension of the resilience CARE model: an ethnographic study". BMC Health Services Research 22, n.º 1 (6 de septiembre de 2022). http://dx.doi.org/10.1186/s12913-022-08482-5.
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Abstract Background Resilient Healthcare research centres on understanding and improving quality and safety in healthcare. The Concepts for Applying Resilience Engineering (CARE) model highlights the relationships between demand, capacity, work-as-done, work-as-imagined, and outcomes, all of which are central aspects of Resilient Healthcare theory. However, detailed descriptions of the nature of misalignments and the mechanisms used to adapt to them are still unknown. Objective The objectives were to identify and classify types of misalignments between demand and capacity and types of adaptations that were made in response to misalignments. Methods The study involved 88.5 hours of non-participant ethnographic observations in a large, teaching hospital in central London. The wards included in the study were: two surgical wards, an older adult ward, a critical care unit, and the Acute Assessment Unit (AAU), an extension unit created to expedite patient flow out of the Emergency Department. Data were collected via observations of routine clinical work and ethnographic interviews with healthcare professionals during the observations. Field notes were transcribed and thematically analysed using a combined deductive-inductive approach based on the CARE model. Results A total of 365 instances of demand-capacity misalignment were identified across the five wards included in the study. Of these, 212 had at least one observed corresponding work adaptation. Misalignments identified include equipment, staffing, process, communication, workflow, and space. Adaptations identified include process, resource redistribution, and extra-role performance. For all misalignment types observed across the five in-patient settings, process adaptations were the most frequently used adaptations. The exception to this was for staffing misalignments, which were most frequently responded to with extra-role performance adaptations. Of the three process adaptations, hospital workers most often adapted by changing how the process was done. Conclusions This study contributes a new version of the CARE model that includes types of misalignments and corresponding adaptations, which can be used to better understand work-as-done. This affords insight into the complexity of the system and how it might be improved by reducing misalignments via work system redesign or by enhancing adaptive capacity.
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van den Heuvel, Machteld, Evangelia Demerouti, Arnold B. Bakker, Jørn Hetland y Wilmar B. Schaufeli. "How do Employees Adapt to Organizational Change? The Role of Meaning-making and Work Engagement". Spanish Journal of Psychology 23 (2020). http://dx.doi.org/10.1017/sjp.2020.55.
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Abstract This multi-wave, multi-source study focuses on the benefits of work engagement for employee adaptation to organizational change. The change entailed the implementation of a flexible office design in an engineering firm, which caused radical change for employees. Building on conservation of resources (COR) theory and change transition models, we predict that work engagement trajectories during change are crucial for successful adaptation. The hypothesized process was that initial employee meaning-making will facilitate work engagement, which, in turn, predicts supervisor-rated adaptive performance (i.e. adaptive work-role performance and extra-role performance) via attitude-to-change. Attitude-to-change was modeled as reciprocally related to work engagement at different points in time. Weekly questionnaires were completed by 71 employees during the first five weeks of the change (296 observations). Latent growth trajectories using weekly engagement measures showed no overall growth, but did show significant variance around the slope of work engagement. Meaning-making and attitude-to-change at the onset were positively related to initial levels, but not to growth of work engagement. Meaning-making was indirectly related to short-term attitude-to-change via work engagement. Short-term attitude-to-change was predictive of supervisor-rated adaptive performance and long-term attitude-to-change. Finally, work engagement (slope) predicted long-term attitude-to-change and supervisor-rated extra-role performance via short-term attitude-to-change. Taken together, the study contributes to knowledge about micro-level transition processes of employee adaptation and the benefits of work engagement during change.
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de Prada Creo, Elena, Mercedes Mareque y Iago Portela-Pino. "The acquisition of teamwork skills in university students through extra-curricular activities". Education + Training ahead-of-print, ahead-of-print (12 de noviembre de 2020). http://dx.doi.org/10.1108/et-07-2020-0185.
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PurposeThis study aims to determine whether university students are successfully acquiring or improving skills related to teamwork through a variety of extra-curricular activities, such as sports, music, volunteering, international group work experiences and professional practices.Design/methodology/approachDescriptive statistics have been calculated to evaluate the normal behaviour of the variables. Accidental sampling was used via a cross-curricular study with a quasi-experimental design. An analysis of means was performed using the Student's t-test.FindingsThe results show the students to have highly developed interpersonal and communication skills, followed by adaptation and decision-making skills. The lowest scores corresponded to coordination and leadership skills. On the other hand, a significant correlation was established between extra-curricular activities and the acquisition of essential teamwork skills.Originality/valueThis study can confirm the important relation between extra-curricular activities and the acquisition of the teamwork skills that play a vital role in the overall development of our students, as well as for their integration into the job market, with particular emphasis on the acquisition of leadership skills which students are most lacking in, but which have shown to improve with any of the proposed activities. The promotion of the extra-curricular activities by the University, could greatly support our students' soft skills acquisition and complement their education.
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Herfst, Sander, Lineke Begeman, Monique I. Spronken, Marjolein J. Poen, Dirk Eggink, Dennis de Meulder, Pascal Lexmond et al. "A Dutch highly pathogenic H5N6 avian influenza virus showed remarkable tropism for extra-respiratory organs and caused severe disease but was not transmissible via air in the ferret model". mSphere, 10 de julio de 2023. http://dx.doi.org/10.1128/msphere.00200-23.
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ABSTRACT Continued circulation of A/H5N1 influenza viruses of the A/goose/Guangdong/1/96 lineage in poultry has resulted in the diversification in multiple genetic and antigenic clades. Since 2009, clade 2.3.4.4 hemagglutinin (HA) containing viruses harboring the internal and neuraminidase (NA) genes of other avian influenza A viruses have been detected. As a result, various HA-NA combinations, such as A/H5N1, A/H5N2, A/H5N3, A/H5N5, A/H5N6, and A/H5N8 have been identified. As of January 2023, 83 humans have been infected with A/H5N6 viruses, thereby posing an apparent risk for public health. Here, as part of a risk assessment, the in vitro and in vivo characterization of A/H5N6 A/black-headed gull/Netherlands/29/2017 is described. This A/H5N6 virus was not transmitted between ferrets via the air but was of unexpectedly high pathogenicity compared to other described A/H5N6 viruses. The virus replicated and caused severe lesions not only in respiratory tissues but also in multiple extra-respiratory tissues, including brain, liver, pancreas, spleen, lymph nodes, and adrenal gland. Sequence analyses demonstrated that the well-known mammalian adaptation substitution D701N was positively selected in almost all ferrets. In the in vitro experiments, no other known viral phenotypic properties associated with mammalian adaptation or increased pathogenicity were identified. The lack of transmission via the air and the absence of mammalian adaptation markers suggest that the public health risk of this virus is low. The high pathogenicity of this virus in ferrets could not be explained by the known mammalian pathogenicity factors and should be further studied. IMPORTANCE Avian influenza A/H5 viruses can cross the species barrier and infect humans. These infections can have a fatal outcome, but fortunately these influenza A/H5 viruses do not spread between humans. However, the extensive circulation and reassortment of A/H5N6 viruses in poultry and wild birds warrant risk assessments of circulating strains. Here an in-depth characterization of the properties of an avian A/H5N6 influenza virus isolated from a black-headed gull in the Netherlands was performed in vitro and in vivo , in ferrets. The virus was not transmissible via the air but caused severe disease and spread to extra-respiratory organs. Apart from the detection in ferrets of a mutation that increased virus replication, no other mammalian adaptation phenotypes were identified. Our results suggest that the risk of this avian A/H5N6 virus for public health is low. The underlying reasons for the high pathogenicity of this virus are unexplained and should be further studied.