19 research outputs found
Investigating Sequence Learning in Anthropoid Primates Using Observational and Experimental Methods
Sequence learning is a crucial aspect of human cognition, being foundational in humans' ability to learn language, develop complex tool use and in the development of cumulative culture. A recent review by Ghirlanda et al (2017) highlights that humans potentially have enhancements in these abilities beyond other animals and therefore sequence learning may be a cognitive capacity that sets us apart from other animals. Understanding how these abilities evolved and may differ in our closest living relatives, the primates, can provide novel insights into these abilities. I start by reviewing the existing literature on observational and experimental research in the anthropoid primates, by providing an overview of the observational and experimental research that has been conducted. Particular focus is paid to the areas of communication, foraging and tool use, as well as evaluating the contributions of different experimental approaches to our understanding of sequence learning abilities in primates. An observational study comparing gorillas and François’ langurs was then conducted, which used Markov Chain Analysis to identify whether these primate species differed in the sequences of behaviours they used while browse feeding. This study identified that gorillas exhibit hierarchical sequence structures in their feeding behaviours, where the langurs didn’t. An experimental study was also conducted, using a novel puzzle box experiment, aiming to provide experimental data on the manual sequence learning abilities of previously understudied species, in this case, François’ langurs and black headed spider monkeys. As the results obtained from this experiment were minimal in regard to evaluating sequence learning abilities, results are discussed in relation to improving the procedures of these kinds of experiments. Particularly when working with zoo-housed primate populations
Investigating the binding potential and downstream effects of ferrocene/ ruthenium (III) complexes with RNA
Cisplatin, one of the most popular chemotherapeutic drugs on the market today, battles cancer by binding to DNA, and causing kinks which obstruct DNA replication and transcription. As a result, cisplatin halts cell proliferation of not only fast-dividing cancerous cells but healthy cells as well. To circumvent the shortcomings of cisplatin, the Anderson lab has synthesized a class of ruthenium (III)/ ferrocene compounds, named the RuLX series. These new hetero- multinuclear complexes may have greater selectivity between cancerous and healthy cells through a proposed synergistic mechanism of their metal centers. Previous work on these novel complexes has demonstrated that they interact with DNA and proteins, suggesting that they may share similar molecular targets as cisplatin. RNA has merged as a new molecular target for metal therapeutics not only due to its chemical similarity with DNA, but also due to its essential role in cellular function. Many metallochemotheraputics target RNA as well as other biomolecules in their mode of action.
The in vitro binding affinity of the RuLX complexes with RNA was investigated using a 504-base RNA encoding the dihydrofolate reductase enzyme. Evidence suggests that RuL2 and RuL3 have a stronger binding affinity to RNA than RuL1. Moreover, in vitro translation of the DHFR mRNA was carried out to observe the potential downstream effects of these interactions. All three complexes exhibited a dose-dependent reduction of DHFR enzyme activity. Investigations with RuL2 specifically, suggest that its inhibition of DHFR activity is likely due to the metal complex binding to RNA. Explorative controls show that RuL2 does not significantly inhibit enzyme activity or ribosomal protein activity
Model Predictive Control Allocation of Systems with Different Dynamics
International audienceSeveral systems are integrated in passenger cars. Some of them are just redundant systems due to safety requirements. Others, are completely different and can interact with each other as long as they are operating inside the same vehicle. Control allocation methods have been successfully implemented in advanced aircrafts to avoid conflicts, especially in the context of redundant systems. In this paper, we will rather focus on coordinating non-redundant advanced chassis systems with different dynamics. This difference in dynamics can be especially problematic when systems exhibit different communication delays. Model Predictive Control Allocation (MPCA) methods are therefore investigated in order to activate the right system at the right moment. Results show that particularly when the most effective system is saturated, another system with a different time delay can be activated few steps before saturation to instantly take over the maneuver. With good knowledge of actuator dynamics and higher computation power, MPCA methods are able to solve complex problems in severe situations
Adaptive Robust Vehicle Motion Control for Future Over-Actuated Vehicles
International audienceMany challenges still need to be overcome in the context of autonomous vehicles. These vehicles would be over-actuated and are expected to perform coupled maneuvers. In this paper, we first discuss the development of a global coupled vehicle model, and then we outline the control strategy that we believe should be applied in the context of over-actuated vehicles. A gain-scheduled H ∞ controller and an optimization-based Control Allocation algorithms are proposed. High-fidelity co-simulation results show the efficiency of the proposed control logic and the new possibilities that could offer. We expect that both car manufacturers and equipment suppliers would join forces to develop and standardize the proposed control architecture for future passenger cars
Coordination Optimale des Systèmes Châssis pour le Contrôle du Mouvement des Voitures
A large interest has been given recently to global chassis control. One of the main reasons for this would be the approach of fully autonomous vehicles. These vehicles, especially the SAE (J3016) level 5 of automation, are expected to replace the human driver in all situations. The automated vehicle should be able to manage coupled situations in harmony where longitudinal control, lateral control, and eventually vertical control are involved. To do so, the vehicle has more than one embedded system per control axis. Equipment suppliers and new entering automotive actors are continually proposing new solutions to satisfy a specific performance required from future passenger cars. Consequently, the car manufacturer has to coordinate different subsystems coming from different stakeholders to ensure a safe and comfortable driving experience. Until these days, car manufactures favoured simple solutions consisting on adding a coordination layer downstream the competing subsystems in order to mitigate eventual conflicts. Most of strategies adopted consist on prioritizing one system over another depending on predictable conflicting scenarios. Autonomous vehicles need additional subsystems to operate safely. Interactions between these subsystems will increase to the point of becoming unpredictable. This thesis focus on the coordination approach that should be adopted by future vehicles. Particularly, the coordination layer is moved upstream the standalone subsystems to ensure an optimal control distribution. This layer acts as a supervisor depending on optimization-based control allocation algorithms. The control synthesis is based on robust control theories to face environmental changes and the vehicle’s parameters and dynamics uncertainties. Results showed first that even regarding today’s vehicles, the upstream approach can offer additional advantages when it comes to multiple objectives problems solving. In addition, the upstream approach is able to coordinate subsystems of vehicles with a higher over-actuation. Fault-tolerance can be ensured between completely different chassis systems, and qualitative objectives, if rigorously formalized, can be satisfied. The more numerous subsystems will get in the future, the more relevant the upstream approach would become to vehicle motion control. We expect that the important benefits shown in this thesis thanks to an optimal upstream coordination approach would encourage car manufacturers and equipment to switch towards more open solutions, propose together the necessary standardizations, and accelerate the autonomous vehicles development.Le contrôle global du châssis a fait récemment l'objet d'une attention particulière. Cela serait motivé surtout par l’approche des véhicules entièrement autonomes. Ces véhicules, en particulier le niveau 5 d’automatisation SAE (J3016), devraient remplacer le conducteur humain dans presque toutes les situations. Le véhicule automatisé devrait être capable de gérer en harmonie des situations couplées où sont intégrés le contrôle longitudinal, latéral et éventuellement vertical. Pour ce faire, le véhicule dispose de plusieurs systèmes intégrés par axe de contrôle. En effet, les équipementiers automobiles et les nouveaux acteurs de l'industrie automobile proposent continuellement de nouvelles solutions pour satisfaire des performances bien spécifiques. Le constructeur automobile doit quant à lui coordonner différents sous-systèmes provenant de différentes parties prenantes afin de garantir une expérience de conduite fiable et confortable. Jusqu'à présent, les constructeurs automobiles privilégiaient des solutions simples consistant à ajouter une couche de coordination en aval des sous-systèmes concurrents afin de limiter les potentiels conflits. La plupart des stratégies adoptées consistent à prioriser un système par rapport à un autre en fonction de certains scénarios conflictuels prévisibles. Les véhicules autonomes ont besoin de sous-systèmes supplémentaires pour fonctionner en toute sécurité. Ainsi, les interactions entre les sous-systèmes s'amplifieront au point de devenir imprévisibles. Cette thèse met l'accent sur l'approche de coordination qui devrait être adoptée par les véhicules du futur. En particulier, la couche de coordination est déplacée en amont des sous-systèmes autonomes pour assurer une distribution de commande optimale. Cette couche agit comme un superviseur basé sur des algorithmes d'allocation optimale du contrôle. La synthèse des correcteurs repose sur les théories du contrôle robuste permettant de faire face aux changements environnementaux et aux incertitudes paramétriques et dynamiques du véhicule. Les résultats ont d’abord montré que même en ce qui concerne les véhicules actuels, l’approche en amont peut offrir des avantages supplémentaires pour ce qui est de la résolution de problèmes à objectifs multiples. En outre, l’approche en amont permet de coordonner les sous-systèmes des véhicules présentant une sur-actionnement plus élevé. La tolérance aux pannes peut être assurée entre des systèmes de châssis complètement différents, et des objectifs qualitatifs, s'ils sont rigoureusement formalisés, peuvent être satisfaits. Plus les sous-systèmes seront nombreux à l'avenir, plus l'approche en amont deviendrait pertinente pour le contrôle du mouvement des véhicules. Nous espérons que les avantages conséquents présentés dans cette thèse grâce à une approche de coordination en amont optimale encourageraient les constructeurs automobiles et leurs équipementiers à opter pour des solutions plus ouvertes, à proposer ensemble les normalisations nécessaires et accélérer ainsi le développement des véhicules autonomes
Detection and quantification of aflatoxin b 1 in cultured Nile tilapia in Mvomero and Mbarali districts of Tanzania
MSc ThesisThis study was carried out to assess farmers’ awareness as well as to detect and quantify
the levels of Aflatoxin B1 in Nile tilapia (Oreochromis niloticus) farms in Mbarali and
Mvomero districts. A total of 36 farmers and extension workers were involved in a
questionnaire survey. Ninety two samples, tilapia (n=62), fish feeds (n=10), organic
manure (n=10) and pond water (n=10) were collected in February 2013 and assessed for
Aflatoxin B1 by a competitive ELISA technique. About 44.4% of the respondents were
aware of Aflatoxin B1. This toxin was found in all samples collected although the levels
between the samples differed significantly (P < 0.05). Out of 92 samples collected, 7.6%
showed Aflatoxin B1 concentration greater than 5.0 μg/kg. Also, out of 62 fish samples
collected from both Districts, 98% were contaminated with Aflatoxin B1 while the
remaining fish samples had Aflatoxin B1 concentration greater than maximum tolerable
limit of 5.0 μg/kg set by TBS/FAO/WHO. The concentration of Aflatoxin B1 in manure
and fish samples was significantly higher in contamination (p= 0.016, and 0.001,
respectively at 95% C.I) in samples collected in Mvomero compared with those from
Mbarali District. In conclusion, most farmers were not aware of aflatoxins or of measures
to control the toxins in the field, which begins with good agricultural and handling
practices (GAP/GHP). Aflatoxin B1 levels in fish were below the internationally
acceptable limits for human consumption. The detection of small quantities suggest a
need for extensive mycotoxin awareness creation and education program as well as the
adoption of good agricultural practices that include proper storage and handling of feeds
in Mvomero and Mbarali Districts.Fisheries Education and Training Agency (FETA) and Enhancing Pro-poor Innovation in Natural Resources and Agricultural Value Chains Programme (EPINAV
Detection and quantification of aflatoxin b 1 in cultured Nile tilapia in Mvomero and Mbarali districts of Tanzania
MSc ThesisThis study was carried out to assess farmers’ awareness as well as to detect and quantify
the levels of Aflatoxin B1 in Nile tilapia (Oreochromis niloticus) farms in Mbarali and
Mvomero districts. A total of 36 farmers and extension workers were involved in a
questionnaire survey. Ninety two samples, tilapia (n=62), fish feeds (n=10), organic
manure (n=10) and pond water (n=10) were collected in February 2013 and assessed for
Aflatoxin B1 by a competitive ELISA technique. About 44.4% of the respondents were
aware of Aflatoxin B1. This toxin was found in all samples collected although the levels
between the samples differed significantly (P < 0.05). Out of 92 samples collected, 7.6%
showed Aflatoxin B1 concentration greater than 5.0 μg/kg. Also, out of 62 fish samples
collected from both Districts, 98% were contaminated with Aflatoxin B1 while the
remaining fish samples had Aflatoxin B1 concentration greater than maximum tolerable
limit of 5.0 μg/kg set by TBS/FAO/WHO. The concentration of Aflatoxin B1 in manure
and fish samples was significantly higher in contamination (p= 0.016, and 0.001,
respectively at 95% C.I) in samples collected in Mvomero compared with those from
Mbarali District. In conclusion, most farmers were not aware of aflatoxins or of measures
to control the toxins in the field, which begins with good agricultural and handling
practices (GAP/GHP). Aflatoxin B1 levels in fish were below the internationally
acceptable limits for human consumption. The detection of small quantities suggest a
need for extensive mycotoxin awareness creation and education program as well as the
adoption of good agricultural practices that include proper storage and handling of feeds
in Mvomero and Mbarali Districts.Fisheries Education and Training Agency (FETA) and Enhancing Pro-poor Innovation in Natural Resources and Agricultural Value Chains Programme (EPINAV
Les effets du transfert de technologie via les IDE sur la performance des exportations : Cas de l'industrie automobile marocaine
<p>Le transfert de technologie via les investissements directs étrangers représente un mécanisme par lequel des connaissances et compétences techniques sont partagées entre l'investisseur étranger et les entreprises du pays d'accueil. Ce transfert technologique pratique un effet positif sur la performance à l'exportation, et ce à travers l'optimisation de la qualification de la main d'œuvre locale qui permet l'amélioration de la qualité et de la diversité des produits destinés à l'export. Dans le cadre de ce travail de recherche, nous avons analysé le rôle joué par les investissements directs étrangers dans le développement des exportations du pays d'hôte en s'appuyant sur le transfert technologique. À cette fin, nous avons diagnostiqué les exportations de l'industrie automobile marocaine. </p><p>Cette étude a pu conclure que le transfert de technologie provenant d'un investissement direct étranger aide à la stimulation des exportations de la globalité du secteur. </p>
La performance à l'exportation dans la sphère de la crise sanitaire : cas du Maroc
Résumé
C’est dans une atmosphère difficile à expliquer, que le coronavirus a attaqué le monde en l’incluant dans un temps d’incertitude sans précédent. La Covid19 a freiné l’activité mondiale en causant de sévères conséquences humaines, financières, économiques et politiques, la croissance mondiale a connu un recul de 3.6%. En effet, l’État marocain a rapidement fait appel aux différents membres du gouvernement afin de faire face à la propagation brutale de la crise du covid19. Malgré ses différentes actions, la performance à l’exportation a été l’une des indicateurs ayant enregistré des baisses rudes expliquées par la diminution des exportations en valeur et en volume tout au long de la période du covid et du post covid. L’objectif de cet article réside dans l’explication de l’effet des répercussions de la crise sanitaire sur la performance des exportations du Maroc. Pour ce faire, un bref rappel théorique des indicateurs de la performance à l’exportation a été cité, ensuite nous avons essayé d’abord de présenter l’impact du covid19 sur l’ensemble de l’économie marocaine et sur les exportations marocaines, puis nous avons analysé l’impact de la crise sur les secteurs exportateurs les plus performants du pays à travers un échantillon de 4 secteurs en optant pour une analyse descriptive. Les différents secteurs de notre étude ont enregistré une baisse très remarquable tout au long de l’année 2020 et ont légèrement repris leur hausse à partir de l’année 2021.
Mots clés : Exportations marocaines, performance à l’export, Covid19, crise, récession économique, industries nationales, relance économique.
Abstract
The coronavirus attacked the world in a difficult atmosphere, plunging it into a time of unprecedented uncertainty. COVID-19 slowed down global activity, causing severe human, financial, economic, and political consequences, with global growth experiencing a decline of 3.6%. The Moroccan government swiftly mobilized various members of the government to address the rapid spread of the COVID-19 crisis. Despite its various actions, export performance was one of the indicators that recorded significant declines, attributed to the decrease in both the value and volume of exports throughout the COVID and post-COVID period. The objective of this article is to explain the impact of the repercussions of the health crisis on Morocco's export performance. To do so, a brief theoretical overview of export performance indicators was provided. Then we first attempted to present the impact of COVID-19 on the overall Moroccan economy and Moroccan exports. Afterward, we analyzed the crisis's impact on the country's most successful export sectors through a sample of four sectors, using a descriptive analysis. The various sectors in our study experienced a very noticeable decline throughout 2020 and began to show a slight recovery from 2021 onwards.
Key words: Moroccan exports, export performance, Covid19, crisis, economic recession, domestic industries, economic recovery