Biot-JKD model: simulation of 1D transient poroelastic waves with fractional derivatives

A time-domain numerical modeling of Biot poroelastic waves is presented. The viscous dissipation occurring in the pores is described using the dynamic permeability model developed by Johnson-Koplik-Dashen (JKD). Some of the coefficients in the Biot-JKD model are proportional to the square root of the frequency: in the time-domain, these coefficients introduce order 1/2 shifted fractional derivatives involving a convolution product. Based on a diffusive representation, the convolution kernel is replaced by a finite number of memory variables that satisfy local-in-time ordinary differential equations. Thanks to the dispersion relation, the coefficients in the diffusive representation are obtained by performing an optimization procedure in the frequency range of interest. A splitting strategy is then applied numerically: the propagative part of Biot-JKD equations is discretized using a fourth-order ADER scheme on a Cartesian grid, whereas the diffusive part is solved exactly. Comparisons with analytical solutions show the efficiency and the accuracy of this approach.Comment: arXiv admin note: substantial text overlap with arXiv:1210.036

Thrombocytopenia and platelet transfusions in ICU patients: an international inception cohort study (PLOT-ICU)

Purpose Thrombocytopenia (platelet count < 150 × 109/L) is common in intensive care unit (ICU) patients and is likely associated with worse outcomes. In this study we present international contemporary data on thrombocytopenia in ICU patients. Methods We conducted a prospective cohort study in adult ICU patients in 52 ICUs across 10 countries. We assessed frequencies of thrombocytopenia, use of platelet transfusions and clinical outcomes including mortality. We evaluated pre-selected potential risk factors for the development of thrombocytopenia during ICU stay and associations between thrombocytopenia at ICU admission and 90-day mortality using pre-specified logistic regression analyses. Results We analysed 1166 ICU patients; the median age was 63 years and 39.5% were female. Overall, 43.2% (95% confidence interval (CI) 40.4–46.1) had thrombocytopenia; 23.4% (20–26) had thrombocytopenia at ICU admission, and 19.8% (17.6–22.2) developed thrombocytopenia during their ICU stay. Non-AIDS-, non-cancer-related immune deficiency, liver failure, male sex, septic shock, and bleeding at ICU admission were associated with the development of thrombocytopenia during ICU stay. Among patients with thrombocytopenia, 22.6% received platelet transfusion(s), and 64.3% of in-ICU transfusions were prophylactic. Patients with thrombocytopenia had higher occurrences of bleeding and death, fewer days alive without the use of life-support, and fewer days alive and out of hospital. Thrombocytopenia at ICU admission was associated with 90-day mortality (adjusted odds ratio 1.7; 95% CI 1.19–2.42). Conclusion Thrombocytopenia occurred in 43% of critically ill patients and was associated with worse outcomes including increased mortality. Platelet transfusions were given to 23% of patients with thrombocytopenia and most were prophylactic.publishedVersio

Epidemiology and outcome predictors in 450 patients with hanging-induced cardiac arrest: a retrospective study

BackgroundCardiac arrest is the most life-threatening complication of attempted suicide by hanging. However, data are scarce on its characteristics and outcome predictors.MethodsThis retrospective observational multicentre study in 31 hospitals included consecutive adults admitted after cardiac arrest induced by suicidal hanging. Factors associated with in-hospital mortality were identified by multivariate logistic regression with multiple imputations for missing data and adjusted to the temporal trends over the study period.ResultsOf 450 patients (350 men, median age, 43 [34–52] years), 305 (68%) had a psychiatric history, and 31 (6.9%) attempted hanging while hospitalized. The median time from unhanging to cardiopulmonary resuscitation was 0 [0–5] min, and the median time to return of spontaneous circulation (ROSC) was 20 [10–30] min. Seventy-nine (18%) patients survived to hospital discharge. Three variables were independently associated with higher in-hospital mortality: time from collapse or unhanging to ROSC&gt;20 min (odds ratio [OR], 4.71; 95% confidence intervals [95%CIs], 2.02–10.96; p = 0.0004); glycaemia &gt;1.4 g/L at admission (OR, 6.38; 95%CI, 2.60–15.66; p &lt; 0.0001); and lactate &gt;3.5 mmol/L at admission (OR, 6.08; 95%CI, 1.71–21.06; p = 0.005). A Glasgow Coma Scale (GCS) score of &gt;5 at admission was associated with lower in-hospital mortality (OR, 0.009; 95%CI, 0.02–0.37; p = 0.0009).ConclusionIn patients with hanging-induced cardiac arrest, time from collapse or unhanging to return of spontaneous circulation, glycaemia, arterial lactate, and coma depth at admission were independently associated with survival to hospital discharge. Knowledge of these risk factors may help guide treatment decisions in these patients at high risk of hospital mortality

La mandragore, de la magie à la matière médicale

LIMOGES-BU Médecine pharmacie (870852108) / SudocLYON1-BU Santé (693882101) / SudocSudocFranceF

Suivi et modélisation des écoulements de lahars au Mont Semeru (Java, Indonésie)

International audienceLahars are fast moving mixtures of debris and water. They have been responsible for 40% of all volcanic fatalities over the past century. Development of numerical models capable of accurately simulating these complex debris flows requires a good understanding of sediment transport processes and flow mechanical properties. To provide constraints on these characteristics, we use hydraulic data measured in a river channel at Semeru volcano during real lahars. In addition, rheological tests have been carried out in laboratory to infer the rheological behavior of lahar constitutive material, while the hydraulic relationship between flow height and discharge in control sections is investigated. These elements are then implemented in a code relying on shallow-water equations to simulate the propagation of gravity-driven surges on real topographies and with real hydrograph inputs

Présentation de l’ expérimentation d’agriculture de type néolithique menée à l’archéosite du parc de la Haute-Île (Neuilly-sur-Marne, France) : mise en œuvre et résultats des cultures céréalières

International audienceThis article presents implementation choices and initial results on crop yields and weed assemblages from a 3-year Neolithic-type agricultural experiment (2017-2020) at the "parc de la Haute-Île" (Department of Seine-Saint-Denis), about 20 km east of Paris (France). The project aimed to experiment the currently accepted farming system for the Early Neolithic in central Temperate Europe (ca. 5500-4900 cal BC), i.e. a system of winter or spring cereal cultivation, conducted on small permanent plots, whose fertility is maintained by a low input of organic amendment.At the "parc de la Haute-Île", work on the plots was minimal (no weeding, no irrigation, low fertiliser input) due to constraints related to labour and time availabilities of the experimental team. The plots were mainly cultivated with the two emblematic hulled wheats of the Linearbandkeramik period (LBK): emmer (Triticum turgidum subsp. dicoccon) and einkorn (Triticum monococcum). The initial state of the experimental site was a meadow surrounded by a wooded hedgerow and the initial soil had an inherent high fertility. The total area given over to the farming experiment was 180 m2 (31.5 m2 per plot). Each year, three plots were cultivated, either in monoculture or in maslin, i.e. cultivation of several cereal types on the same plot and subsequently harvested together. The annual cropping plans included one plot of cereals that had never been fertilized, another amended with animal manure (equivalent of 2 t/ha of animal manure), and another following the cultivation of a pulse crop (rotation). The aim was to evaluate the cereal yields following the different methods that were used (fertilization, seasonality), as well as the qualitative diversity of weed assemblages in the plots and in one processed einkorn subsample, sown in autumn and gathered low on the stem. The main questions underlying the experimental project are:- Does low organic input cultivation without weed control benefit one or the other of the two-hulled wheats in the monoculture and maslin plots?- Does soil fertilisation have a short-term effect on the yields of the hulled cereals?- What is the composition of the wild flora present in the cultivated plots, what is its origin, is it representative of the cultivation methods?- Does the weed flora found in the harvested lots after their treatment reflect the results from the agricultural plots? At the "parc de la Haute-Île", emmer and einkorn competed with herbaceous weeds in the farming experiment with low labour input and low fertilization intensity. The yields for the two cereals show inter-annual but also intra-annual variabilities. Einkorn was the best performing cereal in both the monoculture and maslin plots. The average yield for einkorn is 1350 kg/ha (ratio 1:15) and 900 kg/ha (ratio 1:8,5) for emmer. The yield is always higher than 1:10 for einkorn regardless of when sowing took place and the fertilization methods. For emmer, the ratio is generally less than 1:10. Regarding sowing seasonality, the spring crop tested in year 1 (2018-2019) performed less well than the winter crop for both taxa, with emmer even stopping its development during the agricultural season. On the unfertilized plot, there is a discontinuous evolution of yields between the test year (2017-2018) and year 2 (2019-2020) with the two cereals showing contrasting behaviours. For einkorn in the test year, the unfertilised plot delivered the highest yield (1:23) of the three years. On the five plots fertilized in monoculture, yields were not systematically higher than on the unfertilised plots. For emmer, in year 2, the two fertilized plots (1:12 and 1:17) yielded more than the unfertilized plot (1:7) and even more than the reference value of the test year (1:10). Emmer seems thus to respond somewhat better to short-term fertilisation. These results contradict the current agronomic data that indicate a better productivity of emmer. This experiment leads us to assume that the better performance of einkorn during episodes of heavy rainfall could explain its preponderance on most of the LBK archaeological sites in Central European despite its supposed lower yield. Indeed, the experiment shows that currently, some varieties of einkorn can outperform emmer, several years in a row, under a low input winter cropping system with a soil with high inherent fertility.36 herbaceous species were observed in the cereal plots. Most (n=25) were species identified in the meadow. At least 5 taxa may have originated in the meadow and/or initial seedlings and 2 taxa originated exclusively in the initial seedlings of the test year. The distribution by biological type shows 50% annuals (mostly winter annuals) and 50% perennials (without vegetative reproductive organs in majority). The high presence of perennials can be explained by the short duration of the experiment that did not favour annuals, and the low intensity of weeding. After threshing and winnowing, 10 taxa were identified to the species level in the einkorn stock. The distribution by biological type indicates 80% annuals, which are mostly winter annuals. Among the perennials, those without vegetative reproduction dominate. The ratio of annuals/perennials observed in the einkorn stock is thus not representative of what was observed on the plot. There is less diversity in the assemblage compared to what was recorded in the plots. Furthermore, winter annual weeds are over-represented compared to the ratio recorded in the plots, where perennials dominate. This could be explained by the fact that annuals, such as poppy (Papaver rhoeas) or brome (Bromus sp.), produce more seeds than perennials and are therefore more likely to be present in the samples. This result will have to be verified and explained when the entire harvest subsamples of the three experimental years are processed.L'expérimentation agricole menée dans le parc de la Haute-Île (Département de la Seine-Saint-Denis) pendant trois années agricoles (2017-2020) a pour objectif de tester un système agricole de type néolithique (5500-4900 avant notre ère) impliquant un travail du sol minimal et un taux de fertilisation faible. Cet article présente la mise en oeuvre de l'expérimentation et une analyse préliminaire des résultats concernant les rendements céréaliers et les relevés des cortèges d'adventices. L'amidonnier et l'engrain se sont montrés généralement compétitifs face aux plantes adventices herbacées. Les parcelles semées à l'automne avec la technique du sillon ont permis de récolter en moyenne 1350 kg/ha (ratio 1:15) d'engrain et 900 kg/ha (ratio 1:8,5) d'amidonnier. Cette moyenne est à nuancer en raison de la variabilité interannuelle des rendements pour les deux céréales. Néanmoins, le rendement est toujours supérieur à 1:10 pour l'engrain et en général inférieur à 1:10 pour l'amidonnier. Ainsi, contrairement aux données agronomiques qui indiquent que l'engrain est moins productif que l'amidonnier, l'expérimentation indique que certaines variétés d'engrain peuvent être plus performantes que celles d'amidonnier en culture d'hiver, plusieurs années consécutives, sous un système agraire engageant un très faible apport organique et un faible investissement humain. La flore adventice relevée sur les parcelles est dominée par les plantes vivaces probablement en raison de la faible intensité du travail du sol et de la courte durée de l'expérimentation. La majorité des taxons trouvés dans le lot de stock d'engrain (récolte traitée par battage puis vannage) provient de la prairie environnante. Les adventices résiduelles y représentent seulement un quart de la diversité enregistrée sur les parcelles et sont majoritairement des annuelles d'hiver ce qui ne correspond pas au ratio vivace/annuelle enregistré sur les parcelles

Présentation de l’ expérimentation d’agriculture de type néolithique menée à l’archéosite du parc de la Haute-Île (Neuilly-sur-Marne, France) : mise en œuvre et résultats des cultures céréalières

International audienceThis article presents implementation choices and initial results on crop yields and weed assemblages from a 3-year Neolithic-type agricultural experiment (2017-2020) at the "parc de la Haute-Île" (Department of Seine-Saint-Denis), about 20 km east of Paris (France). The project aimed to experiment the currently accepted farming system for the Early Neolithic in central Temperate Europe (ca. 5500-4900 cal BC), i.e. a system of winter or spring cereal cultivation, conducted on small permanent plots, whose fertility is maintained by a low input of organic amendment.At the "parc de la Haute-Île", work on the plots was minimal (no weeding, no irrigation, low fertiliser input) due to constraints related to labour and time availabilities of the experimental team. The plots were mainly cultivated with the two emblematic hulled wheats of the Linearbandkeramik period (LBK): emmer (Triticum turgidum subsp. dicoccon) and einkorn (Triticum monococcum). The initial state of the experimental site was a meadow surrounded by a wooded hedgerow and the initial soil had an inherent high fertility. The total area given over to the farming experiment was 180 m2 (31.5 m2 per plot). Each year, three plots were cultivated, either in monoculture or in maslin, i.e. cultivation of several cereal types on the same plot and subsequently harvested together. The annual cropping plans included one plot of cereals that had never been fertilized, another amended with animal manure (equivalent of 2 t/ha of animal manure), and another following the cultivation of a pulse crop (rotation). The aim was to evaluate the cereal yields following the different methods that were used (fertilization, seasonality), as well as the qualitative diversity of weed assemblages in the plots and in one processed einkorn subsample, sown in autumn and gathered low on the stem. The main questions underlying the experimental project are:- Does low organic input cultivation without weed control benefit one or the other of the two-hulled wheats in the monoculture and maslin plots?- Does soil fertilisation have a short-term effect on the yields of the hulled cereals?- What is the composition of the wild flora present in the cultivated plots, what is its origin, is it representative of the cultivation methods?- Does the weed flora found in the harvested lots after their treatment reflect the results from the agricultural plots? At the "parc de la Haute-Île", emmer and einkorn competed with herbaceous weeds in the farming experiment with low labour input and low fertilization intensity. The yields for the two cereals show inter-annual but also intra-annual variabilities. Einkorn was the best performing cereal in both the monoculture and maslin plots. The average yield for einkorn is 1350 kg/ha (ratio 1:15) and 900 kg/ha (ratio 1:8,5) for emmer. The yield is always higher than 1:10 for einkorn regardless of when sowing took place and the fertilization methods. For emmer, the ratio is generally less than 1:10. Regarding sowing seasonality, the spring crop tested in year 1 (2018-2019) performed less well than the winter crop for both taxa, with emmer even stopping its development during the agricultural season. On the unfertilized plot, there is a discontinuous evolution of yields between the test year (2017-2018) and year 2 (2019-2020) with the two cereals showing contrasting behaviours. For einkorn in the test year, the unfertilised plot delivered the highest yield (1:23) of the three years. On the five plots fertilized in monoculture, yields were not systematically higher than on the unfertilised plots. For emmer, in year 2, the two fertilized plots (1:12 and 1:17) yielded more than the unfertilized plot (1:7) and even more than the reference value of the test year (1:10). Emmer seems thus to respond somewhat better to short-term fertilisation. These results contradict the current agronomic data that indicate a better productivity of emmer. This experiment leads us to assume that the better performance of einkorn during episodes of heavy rainfall could explain its preponderance on most of the LBK archaeological sites in Central European despite its supposed lower yield. Indeed, the experiment shows that currently, some varieties of einkorn can outperform emmer, several years in a row, under a low input winter cropping system with a soil with high inherent fertility.36 herbaceous species were observed in the cereal plots. Most (n=25) were species identified in the meadow. At least 5 taxa may have originated in the meadow and/or initial seedlings and 2 taxa originated exclusively in the initial seedlings of the test year. The distribution by biological type shows 50% annuals (mostly winter annuals) and 50% perennials (without vegetative reproductive organs in majority). The high presence of perennials can be explained by the short duration of the experiment that did not favour annuals, and the low intensity of weeding. After threshing and winnowing, 10 taxa were identified to the species level in the einkorn stock. The distribution by biological type indicates 80% annuals, which are mostly winter annuals. Among the perennials, those without vegetative reproduction dominate. The ratio of annuals/perennials observed in the einkorn stock is thus not representative of what was observed on the plot. There is less diversity in the assemblage compared to what was recorded in the plots. Furthermore, winter annual weeds are over-represented compared to the ratio recorded in the plots, where perennials dominate. This could be explained by the fact that annuals, such as poppy (Papaver rhoeas) or brome (Bromus sp.), produce more seeds than perennials and are therefore more likely to be present in the samples. This result will have to be verified and explained when the entire harvest subsamples of the three experimental years are processed.L'expérimentation agricole menée dans le parc de la Haute-Île (Département de la Seine-Saint-Denis) pendant trois années agricoles (2017-2020) a pour objectif de tester un système agricole de type néolithique (5500-4900 avant notre ère) impliquant un travail du sol minimal et un taux de fertilisation faible. Cet article présente la mise en oeuvre de l'expérimentation et une analyse préliminaire des résultats concernant les rendements céréaliers et les relevés des cortèges d'adventices. L'amidonnier et l'engrain se sont montrés généralement compétitifs face aux plantes adventices herbacées. Les parcelles semées à l'automne avec la technique du sillon ont permis de récolter en moyenne 1350 kg/ha (ratio 1:15) d'engrain et 900 kg/ha (ratio 1:8,5) d'amidonnier. Cette moyenne est à nuancer en raison de la variabilité interannuelle des rendements pour les deux céréales. Néanmoins, le rendement est toujours supérieur à 1:10 pour l'engrain et en général inférieur à 1:10 pour l'amidonnier. Ainsi, contrairement aux données agronomiques qui indiquent que l'engrain est moins productif que l'amidonnier, l'expérimentation indique que certaines variétés d'engrain peuvent être plus performantes que celles d'amidonnier en culture d'hiver, plusieurs années consécutives, sous un système agraire engageant un très faible apport organique et un faible investissement humain. La flore adventice relevée sur les parcelles est dominée par les plantes vivaces probablement en raison de la faible intensité du travail du sol et de la courte durée de l'expérimentation. La majorité des taxons trouvés dans le lot de stock d'engrain (récolte traitée par battage puis vannage) provient de la prairie environnante. Les adventices résiduelles y représentent seulement un quart de la diversité enregistrée sur les parcelles et sont majoritairement des annuelles d'hiver ce qui ne correspond pas au ratio vivace/annuelle enregistré sur les parcelles

Présentation d’une expérimentation d’agriculture néolithique dans le Bassin parisien (France)

International audienc

Présentation d’une expérimentation d’agriculture néolithique dans le Bassin parisien (France)

International audienc

The use of the French Dimensional Apathy Scale (f-DAS) to assess apathy in schizophrenia: Properties and profiles

International audienceBACKGROUND: Apathy can be defined as a quantitative reduction of self-generated voluntary and purposeful (or goal-directed) behaviour. The literature underlines the triadic dimensional nature of apathy, but in schizophrenia there are inconsistencies due to difficulty in assessment. The Dimensional Apathy Scale (DAS) and its validation into French (f-DAS) provide measurement of three neurobehavioral apathy subtypes: Executive, Emotional and Initiation, but these subtypes have never been explored in schizophrenia. OBJECTIVE: The aims of this study are to assess apathy in schizophrenia with a tri-dimensional tool (the f-DAS), to examine its psychometric properties in schizophrenia and the apathetic profiles of patients with schizophrenia. METHODS: One hundred and ten subjects were recruited. Forty-five belonged to the patients’ group and fifty-five to the control group. They all completed the Mini-International Neuropsychiatric Interview (M.I.N.I), the French National Reading Test (f-NART), the French Dimensional Apathy Scale (f-DAS), the Lille Apathy Rating Scale (LARS) and the Beck Depression Inventory (BDI II). RESULTS: Regarding the total score of the f-DAS and the subscores for each dimension, patients appeared significantly more apathetic than healthy controls. Consistency, validity, concurrent and divergent validity were good. In the patient group, several profiles of apathy were identified. CONCLUSIONS: The f-DAS has good psychometric properties and provides reliable and valid dimensional assessment of apathy in schizophrenia. From a dimensional point of view, using the f-DAS we demonstrated that prevalence of apathy could be underestimated in schizophrenia. Patients with schizophrenia are more impaired on the Executive and Initiative dimensions of apathy