Enregistrement de l'activité dans les conditions naturelles sur les pistes deFormica polyctena
Résumé1oOn donne une technique simple d'enregistrement de l'activité des fourrageuses deF. polyctena sur leurs pistes.2oL'activité dépend non seulement de la distance par rapport au nid, mais encore de la piste considérée.3oL'activité n'est nullement comparable d'une piste à l'autre; l'activité nocturne apparaît très souvent dans les pistes populeuses et peut manquer dans les moins populeuses.4oLes pistes différent donc non seulement quant à leur capacité d'apprentissage et leur agressivité (Chauvin, 1962, 1964), mais aussi quant à leur activité; le comportement est également différent suivant l'âge de la piste, tout au moins dans les pistes qui relient les fourmilières filles à la fourmilière mère.5oL'aller et le retour prédominent à des périodes du jour très irrégulières et qui diffèrent pour chaque piste.6oLa température mesurée près du sol n'a qu'une faible corrélation avec l'activité des fourmis.Summary1oA technique is described which permits an easy recording of forager ants activity ofFormica polyctena on their trails.2oAnts activity is regulated by the distance from the nest, but this regulation is not the same in all the trails.3oAnts activity is not the same in all the trails; nocturnal activity appears very often on roads upon which the rate of flow is very high and may lack entirely on neighbouring, less crowded, roads.4oThe ants on, the differend roads are very heterogeneous regarding not only their activity but also their agressivity, their learning facilities (Chauvin, 1963–1964); their behaviour differ also according to road age; i. e. time clapsed from the road foundation, at least in the trails between a mother-colony and a daughter-colony.5oOutgoing and ongoing are very irregular and don't occur at the same time in different roads.6oTemperature close to the ground shows only a weak correlation with and activity.
Sur la mesure de l'activité des Abeilles au trou de vol d'une ruche a dix cadres
RésuméL'enregistrement de l'activité des ruches sur un appareil d'un type nouveau montre des fluctuations journalières très marquées. Elles ne sont pas en accord avec les variations thermiques ni avec les variations de l'activité solaire. Elles diffèrent beaucoup d'une ruche à l'autre, même quand les ruches sont placées côte à côte. L'enlèvement de tout le couvain, ou au contraire l'introduction de dix cadres de couvain, ne modifie pas visiblement ni rapidement l'activité. Il s'agit très probablement d'un accident statistique. Par contre, l'enregistrement sur huit jours qui efface ces accidents est en bon accord avec les variations thermiques.SummaryHive activity has been recorded with a new apparatus. There are very large variations during the day. These variations are not in correlations either with thermographic or solarigraphic records; and there are very large differences between hives that are close together. There differences are very probably due to teams of bees entering and leaving the hive together. The apparatus can stay in front of the hive for four months without damaging the bees.
Design of a compact and economical remotely operated vehicle for aquatic monitoring
There is a major need for underwater technology for monitoring marine archaeology in a peninsular country like India. In this paper, a compact and economical observation-class remotely operated vehicle (ROV) has been designed and developed for aquatic monitoring and underwater surveys, primarily for archaeological purposes. The ROV is capable of operating at depths of 100ft. It has a USB camera for its vision and can be operated from a surface vehicle whose GPS location is geo-tagged on the video, recorded by the camera. Such an arrangement will help in informing the archaeology department about artifacts that are found in various GPS locations. To eliminate the problem of drag due to heavy tether, a two-wire tether has been implemented using the concept of powerline communication, which serves as the communication link between the ROV and the surface vehicle. The two-wire tether also enables faster video transmission. The control panel of the ROV is a PHP-based graphical user interface (GUI) which is capable of recording and displaying the sensor data. The ROV has been named as ‘ROV CHOLAN’, to commemorate the Chola dynasty (300s BCE – 1279 CE) as the artefacts it may find will belong to that period.