Modern pollen assemblages from grazed vegetation in the western Pyrenees, France: a numerical tool for more precise reconstruction of past cultural landscapes

International audienceModern pollen assemblages from grazed vegetation in the Pyrenees Mountains (France) were studied with the aim of providing a calibrated model for reconstructing past pastoral activities. The modern analogues were selected to cover the major gradients of grazing pressure and degree of openness. The vegetation was surveyed by means of the synusial integrated method, assessing the structure and the patchiness of the pastoral phytoceonoses. A correlative model (Redundancy analysis) was devised relating 61 modern pollen spectra with 37 explanatory vegetation and land-use variables. It was shown that wooded, open grazed and nitrophilous sites are clearly separated from one another and that the model can be simplified using three relevant vegetation types as explanatory variables: dry heathland, semi-open oak forest and overgrazed community, respectively related to gradients of openness, soil richness and grazing pressure. When reconstructing past pastoral activities with fossil pollen spectra, it is important to consider scale-dependent influences of plant species. Low frequencies of well-dispersed taxa such as Artemisia, Chenopodiaceae, Plantago lanceolata and Plantago major/media must be interpreted with care since they reflect more regional, rather than local, input into the pastoral landscape. In contrast, the simultaneous occurrence of Asteroideae, Cichorioideae, Cirsium-type, Galium-type, Ranunculaceae, Stellaria-type and Potentilla-type pollen is clearly related to grazing on a local scale. Calculation of Davis indices also shows that Cichorioideae, Galium-type and Potentilla-type indicate the very local presence of the corresponding plants. These pastoral plant indicators may have a limited geographical validity, ie, mountainous regions with crystalline bedrock, which may indeed also provide the framework for the application to fossil spectra of the modern pollen/vegetation/land-use models presented here

Pollen productivity estimates and relevant source area of pollen for selected plant taxa in a pasture woodland landscape of the Jura Mountains (Switzerland)

Relevant source area of pollen (RSAP) and pollen productivity for 11 key taxa characteristic of the pasture woodland landscape of the Jura Mountains, Switzerland, were estimated using pollen assemblages from moss polsters at 20 sites. To obtain robust pollen productivity estimates (PPEs), we used vegetation survey data at a fine spatial-resolution (1 x 1 m(2)) and randomized locations for sampling sites, techniques rarely used in palynology. Three Extended R value (ERV) submodels and three distance-weighting methods for plant abundance calculation were applied. Different combinations of the submodels and distance-weighting methods provide slightly different estimates of RSAP and PPEs. Although ERV submodel 1 using 1/d (d = distance in meters) best fits the dataset, PPE values for heavy pollen types (e.g. Abies) were sensitive to the method used for distance-weighting. Taxon-specific distance-weighting methods, such as Prentice's model, emphasize the intertaxonomic differences in pollen dispersal and deposition, and are thus theoretically sound. For the dataset obtained in this project, Prentice's model was more appropriate than other distance-weighting methods to estimate PPEs. Most of the taxa have PPEs equal to (Fagus, Plantago media and Potentilla-type), or higher (Abies, Picea, Rubiaceae and Trollius europaeus) than Poaceae (PPE = 1). Acer, Cyperaceae, and Plantago montana-type are low pollen producers. This set of PPEs will be useful for reconstructing heterogeneous, mountainous pasture woodland landscapes from fossil pollen records. The RSAP for moss polsters in this semi-open landscape region is ca. 300 m

New 8-nitroquinolinone derivative displaying submicromolar in vitro activities against both Trypanosoma brucei and cruzi

International audienceAn antikinetoplastid pharmacomodulation study was conducted at position 6 of the 8-nitroquinolin-2(1H)-one pharmacophore. Fifteen new derivatives were synthesized and evaluated in vitro against L. infantum, T. brucei brucei, and T. cruzi, in parallel with a cytotoxicity assay on the human HepG2 cell line. A potent and selective 6-bromo-substituted antitrypanosomal derivative 12 was revealed, presenting EC50 values of 12 and 500 nM on T. b. brucei trypomastigotes and T. cruzi amastigotes respectively, in comparison with four reference drugs (30 nM ≤ EC50 ≤ 13 μM). Moreover, compound 12 was not genotoxic in the comet assay and showed high in vitro microsomal stability (half life >40 min) as well as favorable pharmacokinetic behavior in the mouse after oral administration. Finally, molecule 12 (E° = −0.37 V/NHE) was shown to be bioactivated by type 1 nitroreductases, in both Leishmania and Trypanosoma, and appears to be a good candidate to search for novel antitrypanosomal lead compounds

Optimisation Stochastique pour la gestion des lits d’hospitalisation sous incertitudes

Hospitals have to deals with a lot of random events making their management hard to realize. Those difficulties are mainly due to the uncertainty relative to future evolutions of demand, in particular in term of future arrivals and departures. Despite those difficulties, a fast and efficient hospitalization is required especially for some units like the emergency department. This department has to find quick solution to the problem of hospitalized of their patients. This can only be possible if (i) emergency arrivals are forecasted and so a bed is remaining free for them and/or (ii) the planning of beds occupation is made in a way allowing easy allocations of emergency patients.Our purpose is going to manage the patient flow in short stay unit (medicine and surgery) starting form the choice of an admission date for each patient until their discharge by keeping in mind the two previous assumptions. By using some stochastic optimization models, we solve a succession of decision problems in order to grant the good state of hospitals. Three level of decision are solved: 1. Admission scheduling for elective patients, 2. Patient assignment to hospital floors, 3. Patient assignment to rooms.Cases of study are based on data provided by a french hospital partner of this work, Firminy's Hospital CenterLes services de soins hospitaliers sont soumis à de nombreux évènements de natures aléatoires rendant leur gestion et leur pilotage difficiles. Ces difficultés organisationnelles reposent essentiellement sur l'incertitude permanente pesant sur les évolutions futurs, principalement en termes d'arrivées et de départs de patients. Pourtant, une prise en charge rapide et efficace des patients est primordiale pour des services tels que les urgences. Ces services doivent pouvoir placer rapidement leurs patients ce qui n'est possible uniquement si (i) les arrivées ont été anticipées et des places sont laissées vacantes dans les services pour recevoir les patients urgents et/ou (ii) le planning d'occupation des services est construit de telle manière que l'insertion d'un nouveau patient est facilitée.Notre objectif va être de gérer les flux de patients séjournant dans les services de courts-séjours de l'hôpital, depuis le choix d'admission d'un nouveau patient jusqu'à sa sortie, et ce, en s'inspirant des deux postulats précédant. A l'aide de modèles d'optimisation stochastique, une succession de problèmes de décisions, ayant pour but de garantir le bon fonctionnement des structures hospitalières, est résolue. Une hiérarchie en trois niveaux est appliquée pour résoudre le problème de gestion: 1. Planification des admissions des patients réguliers, 2. Affectation des patients aux unités de soins et insertion des urgences, 3. Affectation des patients d'un service aux chambres.Les études de cas sont basées sur les données d'un établissement partenaire, le Centre Hospitalier de Firminy (France)

Stochastic optimization for hospital beds management under uncertainties

Les services de soins hospitaliers sont soumis à de nombreux évènements de natures aléatoires rendant leur gestion et leur pilotage difficiles. Ces difficultés organisationnelles reposent essentiellement sur l'incertitude permanente pesant sur les évolutions futurs, principalement en termes d'arrivées et de départs de patients. Pourtant, une prise en charge rapide et efficace des patients est primordiale pour des services tels que les urgences. Ces services doivent pouvoir placer rapidement leurs patients ce qui n'est possible uniquement si (i) les arrivées ont été anticipées et des places sont laissées vacantes dans les services pour recevoir les patients urgents et/ou (ii) le planning d'occupation des services est construit de telle manière que l'insertion d'un nouveau patient est facilitée.Notre objectif va être de gérer les flux de patients séjournant dans les services de courts-séjours de l'hôpital, depuis le choix d'admission d'un nouveau patient jusqu'à sa sortie, et ce, en s'inspirant des deux postulats précédant. A l'aide de modèles d'optimisation stochastique, une succession de problèmes de décisions, ayant pour but de garantir le bon fonctionnement des structures hospitalières, est résolue. Une hiérarchie en trois niveaux est appliquée pour résoudre le problème de gestion: 1. Planification des admissions des patients réguliers, 2. Affectation des patients aux unités de soins et insertion des urgences, 3. Affectation des patients d'un service aux chambres.Les études de cas sont basées sur les données d'un établissement partenaire, le Centre Hospitalier de Firminy (France).Hospitals have to deals with a lot of random events making their management hard to realize. Those difficulties are mainly due to the uncertainty relative to future evolutions of demand, in particular in term of future arrivals and departures. Despite those difficulties, a fast and efficient hospitalization is required especially for some units like the emergency department. This department has to find quick solution to the problem of hospitalized of their patients. This can only be possible if (i) emergency arrivals are forecasted and so a bed is remaining free for them and/or (ii) the planning of beds occupation is made in a way allowing easy allocations of emergency patients.Our purpose is going to manage the patient flow in short stay unit (medicine and surgery) starting form the choice of an admission date for each patient until their discharge by keeping in mind the two previous assumptions. By using some stochastic optimization models, we solve a succession of decision problems in order to grant the good state of hospitals. Three level of decision are solved: 1. Admission scheduling for elective patients, 2. Patient assignment to hospital floors, 3. Patient assignment to rooms.Cases of study are based on data provided by a french hospital partner of this work, Firminy's Hospital Cente

Optimisation Stochastique pour la gestion des lits d'hospitalisation sous incertitudes

Les services de soins hospitaliers sont soumis à de nombreux évènements de natures aléatoires rendant leur gestion et leur pilotage difficiles. Ces difficultés organisationnelles reposent essentiellement sur l'incertitude permanente pesant sur les évolutions futurs, principalement en termes d'arrivées et de départs de patients. Pourtant, une prise en charge rapide et efficace des patients est primordiale pour des services tels que les urgences. Ces services doivent pouvoir placer rapidement leurs patients ce qui n'est possible uniquement si (i) les arrivées ont été anticipées et des places sont laissées vacantes dans les services pour recevoir les patients urgents et/ou (ii) le planning d'occupation des services est construit de telle manière que l'insertion d'un nouveau patient est facilitée.Notre objectif va être de gérer les flux de patients séjournant dans les services de courts-séjours de l'hôpital, depuis le choix d'admission d'un nouveau patient jusqu'à sa sortie, et ce, en s'inspirant des deux postulats précédant. A l'aide de modèles d'optimisation stochastique, une succession de problèmes de décisions, ayant pour but de garantir le bon fonctionnement des structures hospitalières, est résolue. Une hiérarchie en trois niveaux est appliquée pour résoudre le problème de gestion: 1. Planification des admissions des patients réguliers, 2. Affectation des patients aux unités de soins et insertion des urgences, 3. Affectation des patients d'un service aux chambres.Les études de cas sont basées sur les données d'un établissement partenaire, le Centre Hospitalier de Firminy (France).Hospitals have to deals with a lot of random events making their management hard to realize. Those difficulties are mainly due to the uncertainty relative to future evolutions of demand, in particular in term of future arrivals and departures. Despite those difficulties, a fast and efficient hospitalization is required especially for some units like the emergency department. This department has to find quick solution to the problem of hospitalized of their patients. This can only be possible if (i) emergency arrivals are forecasted and so a bed is remaining free for them and/or (ii) the planning of beds occupation is made in a way allowing easy allocations of emergency patients.Our purpose is going to manage the patient flow in short stay unit (medicine and surgery) starting form the choice of an admission date for each patient until their discharge by keeping in mind the two previous assumptions. By using some stochastic optimization models, we solve a succession of decision problems in order to grant the good state of hospitals. Three level of decision are solved: 1. Admission scheduling for elective patients, 2. Patient assignment to hospital floors, 3. Patient assignment to rooms.Cases of study are based on data provided by a french hospital partner of this work, Firminy's Hospital CenterST ETIENNE-ENS des Mines (422182304) / SudocSudocFranceF

Scheduling preparation of doses for a chemotherapy service

DOI 10.1007 /s10479-009-0624-2 http://www.springerlink.com/content/j15506t4m7377312/International audienceA fast realization of drugs is an important part in the quality of service of a hospital. In this paper we propose a scheduling method for the preparation of chemotherapy doses in order to reduce the patient waiting time. Two approaches have been defined: an off-line approach and a real time approach. The off-line approach is using a linear programming model for minimizing the maximum tardiness of jobs in a production day. This method is re-used during the real-time resolution combined with a greedy algorithm. The solution obtained respects constraints on the production center and the hospital organization. Our model is currently used in software which helps the decision maker of the service and allows increasing the patient satisfaction and the productivity of the service

Scheduling activities in a chemotherapy service

International audienc

Modern pollen assemblages from grazed vegetation in the western Pyrenees, France: a numerical tool for more precise reconstruction of past cultural landscapes

Modern pollen assemblages from grazed vegetation in the Pyrenees Mountains (France) were studied with the aim of providing a calibrated model for reconstructing past pastoral activities. The modern analogues were selected to cover the major gradients of grazing pressure and degree of openness. The vegetation was surveyed by means of the synusial integrated method. assessing the structure and the patchiness of the pastoral phytoceonoses. A correlative model (Redundancy analysis) was devised relating 61 modern pollen spectra with 37 explanatory vegetation and land-use variables. It was shown that wooded, open grazed and nitrophilous sites are clearly separated from one another and that the model can be simplified using three relevant vegetation types as explanatory variables: dry heathland, semi-open oak forest and overgrazed community, respectively related to gradients of openness, soil richness and grazing pressure. When reconstructing past pastoral activities with fossil pollen spectra, it is important to consider scale-dependent influences of plant species. Low frequencies of well-dispersed taxa such as Artemisia, Chenopodiaceae, Plantago lanceolata and Plantago major/media must be interpreted with care since they reflect more regional, rather than local, input into the pastoral landscape. In contrast. the simultaneous occurrence of Asteroideae, Cichorioideae; Cirsium-type. Galium-type. Ranunculaceae. Stellaria-type and Potentilla-type pollen is clearly related to grazing on a local scale. Calculation of Davis indices also shows that Cichorioideae, Galium-type and Potentilla-type indicate the very local presence of the corresponding plants. These pastoral plant indicators may have a limited geographical validity, ie. mountainous regions with crystalline bedrock, which may indeed also provide the framework for the application to fossil spectra of the modern pollen/vegetation/land-use models presented here

Scheduling preparation of doses for a chemotherapy service

International audienceA fast realization of drugs is an important part in the quality of service of a hospital. In this paper we propose a scheduling method for the preparation of chemotherapy doses in order to reduce the patient waiting time. Two approaches have been defined: an off-line approach and a real time approach. The off-line approach is using a linear programming model for minimizing the maximum tardiness of jobs in a production day. This method is re-used during the real-time resolution combined with a greedy algorithm. The solution obtained respects constraints on the production center and the hospital organization. Our model is currently used in software which helps the decision maker of the service and allows increasing the patient satisfaction and the productivity of the service