Mathematical modeling of an urban pigeon population subject to local management strategies

International audienceThis paper addresses the issue of managing urban pigeon population using some possible actions that makes it reach a density target with respect to socio-ecological constraints. A mathematical model describing the dynamic of this population is introduced. This model incorporates the effect of some regulatory actions on the dynamic of this population. We then used mathematical viability theory, which provides a framework to study compatibility between dynamics and state constraints. The viability study shows when and how it is possible to regulate the pigeon population with respect to the constraints

The geographic scale of genetic differentiation in the feral pigeon (Columba livia): implications for management

Understanding the genetic connectivity among populations of spreading and problematic species is important to determine the spatial scale at which management actions need to be conducted. The feral pigeon (Columba livia) is considered to be a pest or an invasive species in many cities around the world, leading to frequent attempts to control its populations. In the present study, we used microsatellites markers to investigate the relationship between genetic structure and geographic distance among feral pigeons from different locations, and the patterns of genetic differentiation at two geographic scales, within and between urbanised areas. A Mantel’s test revealed that the levels of genetic differentiation increased significantly with the geographic distance separating the locations. We also found that neighbouring locations within urban areas are usually not genetically differentiated, suggesting that all of the feral pigeons in an urban zone constitute a single management unit. Our results suggest that in large, interconnected cities control by culling at the scale of a neighbourhood, in addition of generating ethical issues, will not be effective to decrease pigeon population sizes

Beneficial effect of insulin-like growth factor-1 on hypoxemic renal dysfunction in the newborn rabbit

Acute normocapnic hypoxemia can cause functional renal insufficiency by increasing renal vascular resistance (RVR), leading to renal hypoperfusion and decreased glomerular filtration rate (GFR). Insulin-like growth factor 1 (IGF-1) activity is low in fetuses and newborns and further decreases during hypoxia. IGF-1 administration to humans and adult animals induces pre- and postglomerular vasodilation, thereby increasing GFR and renal blood flow (RBF). A potential protective effect of IGF-1 on renal function was evaluated in newborn rabbits with hypoxemia-induced renal insufficiency. Renal function and hemodynamic parameters were assessed in 17 anesthetized and mechanically ventilated newborn rabbits. After hypoxemia stabilization, saline solution (time control) or IGF-1 (1mg/kg) was given as an intravenous (i.v.) bolus, and renal function was determined for six 30-min periods. Normocapnic hypoxemia significantly increased RVR (+16%), leading to decreased GFR (−14%), RBF (−19%) and diuresis (−12%), with an increased filtration fraction (FF). Saline solution resulted in a worsening of parameters affected by hypoxemia. Contrarily, although mean blood pressure decreased slightly but significantly, IGF-1 prevented a further increase in RVR, with subsequent improvement of GFR, RBF and diuresis. FF indicated relative postglomerular vasodilation. Although hypoxemia-induced acute renal failure was not completely prevented, IGF-1 elicited efferent vasodilation, thereby precluding a further decline in renal functio

Effect of aging on calcium signaling in C57Bl6J mouse cerebral arteries

In cerebral arteries, alterations of vascular reactivity have been observed but not well molecularly characterized. Therefore, we have hypothesized that cerebrovascular reactivity could be modified by aging via a modification of Ca²⁺ signaling in smooth muscle cells. Ca²⁺ signals and gene expression implicated in contraction have been measured in posterior and middle cerebral arteries from young (2–3 months) and old (20–22 months) C57Bl6/J mice. Aging induced a decrease of KCl- and caffeine-induced contraction as well as a decrease of the amplitudes and an increase of the durations of KCl- and caffeine-induced Ca²⁺ signals. These results could be linked with the decrease of gene expression coding for Cav1.2, RyR2, SERCA2, PLB, STIM1, TRIC-B, and the increase of FKBP12.6 and TPCN1 gene expression. Finally, aging induced a modification of InsP3 subtype expression pattern responsible for a modification of the InsP3 affinity to activate Ca²⁺ signals. These results show that aging induces a decrease of contractility correlated with modifications of the expression of genes encoding Ca²⁺ signaling toolkit. Globally, the amplitude of Ca²⁺ signals was decreased, whereas their duration was increased by a defection of Ca²⁺ store refilling

Explorando la relación ser humano-naturaleza: agricultura urbana, ciencias de la conservación y ciudad

La tendencia dominante de las ciencias de la conservación y del urbanismo, ha buscado detener el deterioro ambiental estableciendo una base ética de actitudes consideradas apropiadas para conservar una naturaleza particular. A través del estudio de 9 jardines comunitarios parisinos, mostramos los límites que muestra esta aproximación al limitar la interacción ser humano-naturaleza. Tomando en cuenta subjetividades ciudadanas, brindamos perspectivas para nutrir las ciencias de la conservación y repensar las ciudades, en vista a alimentar la reflexión sobre el desafío global mayor que es la conservación de la naturaleza

Assessing the emergence of pro-biodiversity practices in citizen scientists of a backyard butterfly survey

International audienc

Impaired social cognition in schizophrenia during the Ultimatum Game: An EEG study

Schizophrenia has a core feature of cognitive dysfunctions. Since these deficits are predictive for patients' functional outcome, understanding their origin is of great importance to improve their daily lives. A specific component of the deficit involves social decision-making, which can be studied using the Ultimatum Game (UG). In this task, a “proposer” proposes a share of money to a “responder”, who can either accept or reject this offer. If the responder accepts the proposal, both win money. If the responder refuses, both players end up with nothing. Therefore, the UG evaluates decision-making strategies and social interaction.Methods: We compared the neuronal bases of schizophrenic patients with healthy controls, while performing the UG. Electroencephalography (EEG) was used to find differences in the event-related potential (ERP) components typical for the UG, namely the P2 and feedback-related negativity (FRN). Source reconstruction was further used to define the origin of these differences.Results: In the proposer condition, no differences were found in amplitude of the P2 and FRN components. In contrast, in the responder condition, significant differences were found for the amplitude of the FRN (p = 0.009). Using source reconstruction, a different activation in a border zone of the dorsolateral and the medial prefrontal cortex was revealed in schizophrenic patients to underlie this component.Conclusions: We suggest that the difference found in the FRN amplitude is associated with difficulties of patients in interpreting another's behavior. Although schizophrenic patients correctly activate neuronal bases in the proposer condition, they were not able to activate the same networks in the responder condition, thereby exposing their difficulties in social interaction

ANNODIS : une approche outillée de l'annotation de structures discursives

International audienceThe ANNODIS project has two interconnected objectives: to produce a corpus of texts annotated at discourse-level, and to develop tools for corpus annotation and exploitation. Two sets of annotations are proposed, representing two complementary perspectives on discourse organisation: a bottom-up approach starting from minimal discourse units and building complex structures via a set of discourse relations; a top-down approach envisaging the text as a whole and using pre-identified cues to detect discourse macro-structures. The construction of the corpus goes hand in hand with the development of two interfaces: the first one supports manual annotation of discourse structures, and allows different views of the texts using NLP-based pre-processing; another interface will support the exploitation of the annotations. We present the discourse models and annotation protocols, and the interface which embodies them.Le projet ANNODIS vise la construction d'un corpus de textes annotés au niveau discursif ainsi que le développement d'outils pour l'annotation et l'exploitation de corpus. Les annotations adoptent deux points de vue complémentaires : une perspective ascendante part d'unités de discours minimales pour construire des structures complexes via un jeu de relations de discours ; une perspective descendante aborde le texte dans son entier et se base sur des indices pré-identifiés pour détecter des structures discursives de haut niveau. La construction du corpus est associée à la création de deux interfaces : la première assiste l'annotation manuelle des relations et structures discursives en permettant une visualisation du marquage issu des prétraitements ; une seconde sera destinée à l'exploitation des annotations. Nous présentons les modèles et protocoles d'annotation élaborés pour mettre en œuvre, au travers de l'interface dédiée, la campagne d'annotation

Les ateliers du hameau Les Noires Terres à Messein (Meurthe-et-Moselle, Lorraine, France) :

L’occupation altomédiévale (VIe-VIIIe s.) au lieu-dit Les Noires Terres sur la commune de Messein, au sud de Nancy (Meurthe-et-Moselle, France, fouille 2003-2004), associe des unités composées d’un bâtiment d’habitation et de structures de type agricole (greniers, silos, enclos, cabanes excavées…) à des ateliers de production et de travail du fer (préparation du minerai, fabrication du charbon de bois, fourneaux de réduction, forgeage du fer). La présence des déchets relevant d’une chaîne opératoire complète (de la préparation du minerai à l’élaboration de produits finis), documentée par l’étude paléométallurgique, ainsi que le volume de production estimé au vu de leur quantité (plusieurs dizaines de tonnes de fer), suggèrent qu’il s’agit de l’activité principale des occupants et non pas d’une activité d’appoint aux pratiques agricoles. La nature de l’occupation est donc discutée : les vestiges découverts correspondraient aux unités d’habitation d’artisans spécialisés, avec leurs ateliers, comportant l’ensemble des installations et équipements nécessaires à leur subsistance et à leur vie quotidienne. On peut ainsi émettre l’hypothèse qu’il s’agit d’une des formes d’organisation de la production du fer dans le monde franc au cours du premier Moyen Âge, et qu’elle correspond peut-être à ce que nous laissent entrevoir les polyptiques de la période carolingienne.The Altomedieval occupation (6th-8th c.) at Les Noires Terres in Messein, to the south of Nancy (Meurthe-et-Moselle, France, excavation 2003-2004), associates elements composed of a dwelling and agricultural structures (granaries, silos, enclosures, excavated huts, etc.) with iron production and transformation workshops (iron ore preparation, wood charcoal production, reduction furnaces, iron forging). The presence of waste products corresponding to a complete chaîne opératoire (production sequence) (from iron ore preparation to finished products), documented by the paleo-metallurgical study and the production volume estimated from their quantity (several dozen tons of iron), suggest that this was the main activity of the occupants, rather than an activity secondary to agricultural activities. The nature of the occupation is thus discussed : the remains discovered could correspond to the dwellings of the specialized artisans, with their workshops, including all the installations and equipment necessary for their subsistence and daily life. We can thus propose the hypothesis that this was one of the forms of iron production organization employed by the Franks during the Early Middle Ages, and that if might correspond to that which is suggested by the polyptyques of the Carolingian period.Die frühmittelalterliche Besiedlung (6.-8. Jh.) von Les Noires Terres auf dem Gebiet der Gemeinde Messein, südlich von Nancy (Departement Meurthe-et-Moselle, Frankreich, Ausgrabung 2003-2004), besteht aus Siedlungseinheiten, die sich jeweils aus einem Wohnbau mit landwirtschaftlichen Einrichtungen (Speicherbauten, Silos, Einfriedungen, Grubenhäuser…) und Werkstätten für die Eisengewinnung und -verarbeitung (Erzaufbereitung, Holzkohlengewinnung, Rennöfen, Eisenschmieden) zusammensetzen. Die Abfälle, die von einem kompletten, durch die paläometallurgische Studie dokumentierten Verhüttungsprozess (von der Erzaufbereitung bis hin zur Formgebung der Endprodukte) zeugen, sowie das anhand der Abfälle geschätzte Produktionsvolumen (mehrere Dutzend Tonnen Eisen) legen nahe, dass es sich hier um die Hauptbeschäftigung der Bewohner handelte und nicht um eine Nebentätigkeit. Demzufolge steht die Art der Besiedlung zur Diskussion: Die Funde und Befunde würden einer auf die Eisengewinnung und -verarbeitung spezialisierte Handwerkersiedlung entsprechen mit allen für die Arbeit und den Alltag der Bewohner notwendigen Anlagen und Einrichtungen, Wohnhäusern und Werkstätten. So können wir die Hypothese vorlegen, dass es sich um eine der Organisationsformen der frühmittelalterlichen fränkischen Eisenmetallurgie handelt, welche die Urbare der karolingischen Periode erahnen lassen