492 research outputs found
Modélisation de la propagation de l'impulsion électrique dans un modèle de tissu cardiaque tridimensionnel
Excitation cardiaque normale -- Arythmie cardiaque -- Historique de la modélisation de la propagation -- Modélisation de la propagation -- Modélisation de la réentrée -- Méthodes -- Modèle membranaire -- Modèle de propagation -- Solution générale -- Algorithme de solution -- Simulation de la propagation -- Simulation de la réentrée dans un modèle de tissu bidimensionnel -- Simulation de la réentrée dans un modèle de tissu tridimensionnel
Streptococcus Intermedius Brain and Diverticular Abscesses After Dental Manipulation: A Case Report.
A brain abscess is defined as a focal intracerebral infection consisting of an encapsulated collection of pus, which can be a life-threatening complication of infections, trauma, or surgery. While immunocompromised patients can have a wide array of causative organisms, bacterial species represent the most common etiology in immunocompetent individuals. The incidence of brain abscesses ranges from 0.4 to 0.9 per 100,000, with a high predisposition among immunocompromised patients and in those with disruption of the blood-brain barrier. The most common causative organisms found were Streptococcus species, particularly S. viridians and S. pneumonia, Enterococcus, and Staphylococcus species, mainly S. aurieus and S. epidermidis. Microorganism can invade the brain through different mechanisms, either directly by contiguous spread and odontogenic infections, which usually cause a single brain abscess, or indirectly through hematogenous spread which can cause multiple brain abscesses. Both surgical and conservative dental procedures contribute to hematogenous spreading of oral microorganisms. Although most of those organisms are eliminated shortly after they gain access to the bloodstream, some can persist and contribute to the pathogenesis of abscesses in the appropriate environment. Odontogenic origins are rarely implicated in the formation of brain abscesses, and oral foci comprise approximately 5% of identified cases. We report a case of brain and diverticular abscesses due to S. intermidius occurring two months after dental extraction. This case highlights the fact that even usual dental workup can result in the development of bacteremia and disseminated abscesses including but not restricted to the brain. Consequently, in addition to identifying the possible source of bacteremia with an extensive history and physical exam, the diagnosis of Streptococcus milleri organisms should prompt the physicians to screen for sites of possible metastatic infection spread
Assessing actual evapotranspiration in irrigation districts using Landsat TM images and SEBAL model: Potential uses for irrigation monitoring
Satellite imagery allows the observation of large land stretches and the acquisition of worthwhile information that can be used efficaciously in agro-hydrologic systems. On the other hand, remotely sensed data coupled with energy balance models represent reliable tools to estimate actual evapotranspiration (ET).
Objective of the research was to propose a methodology to estimate ET by using Landsat TM images and surface energy balance, thus allowing the monitoring of current irrigation practices and/or possible vegetation stress.
The proposed methodology was applied in an irrigation district managed by \u201cConsorzio di Bonifica Agrigento 3\u201d, Castelvetrano, Sicily (Italy), in which water is distributed by a pressurized distribution network operating on-turn.
Satellite information retrieved by a set of Landsat TM images allowed to implement the surface energy balance model (SEBAL) in order to map the spatial distribution of instantaneous ET over two main crops (olives and grapevines), during irrigation seasons (from May to September) 2009 and 2010. These instantaneous values were then up-scaled to daily values based on the hypothesis of self-preservation of evaporative fraction. Finally, daily acquisitions were used to derive ET within longer time intervals, by assuming the by assuming proportionality to temporal dynamics of the reference evapotranspiration (ET0) computed using standard ground meteo-data.
With reference to the acquisition days, the comparison between SEBAL outputs and maximum daily crop evapotranspiration (ETc) estimated with the FAO 56 approach, showed notable stress levels for both the investigated crops, except for the images acquired in May, when significant rainfall occurred in both years. Moreover, measurements of eddy covariance fluxes collected by a tower located in the district within an olive orchard, evidenced the general reliability of daily ET retrieved by the model and consequently the validity of the self-preservation hypothesis applied to upscale instantaneous ET. Even if the applied methodology can be considered a valuable tool to monitor irrigation practices, the availability of cloud-free satellite images, as well as the temporal frequency of sensing, are critical issues for the proposed applications
Identifying and Addressing Soil Property Issues Affecting Roadside Vegetation Establishment
Attaining adequate vegetation cover along highways is important for NDOR to comply with EPA’s stormwater regulations. However, low plant cover is a common problem on shoulders (first 16 feet off the pavement) of many highways in Nebraska. The ultimate goal of this study is to identify cost-effective engineering solutions that assure adequate seed beds (i.e., soil conditions) for establishment of selected seeding mixtures. The objectives of this study are to (1) characterize the soil properties along roadsides where vegetation stands have not developed well, and (2) verify the effects of select soil property parameters on plant germination and establishment.
Sampling occurred at multiple locations along the highways near Beaver Crossing and Sargent, NE. At each location, soil samples were collected from a transect of multiple landscape positions, perpendicular to the highway. The soil physical properties measured included cone index, sorptivity, and aggregate stability, while the soil chemical properties measured included EC, pH, organic matters, Na, and Ca. Results show that the soils near the edge of the highway pavement were highly compacted. Also, the soils had higher pH, lower organic matter, and higher salt levels than optimal conditions. In the subsequent greenhouse studies, a factorial design was used to test three factors: soil compaction (i.e., 1.5, 1.7, and 1.9 g cm-3 soil compaction levels as well as sand as control), timing of salt stress (2 pulses of salt treatment applied pre-germination and post-germination as well as no-salt control), and plant species (buffalo grass, tall fescue, and western wheat grass). Results from the greenhouse studies showed that the three plant species exhibited different germination and early survival responses to the soil compaction and salt treatments. Tall fescue is better suited for site re-vegetation especially if salt is present in the soil prior to germination. Statistical analysis show that salt treatment had the most impact on species performance.
Finally the project recommends a few engineering remediation strategies for plant establishment. Creating microsites on compacted soil surfaces could potentially alleviate the soil compaction issue by creating local environmental conditions favorable to plant establishment at microsites. To remediate the high salt levels in soil, it is recommended to consider alternative de-icing agents and amend zeolites and organics in soil
RELIGION AND RELIGIOSITY: A WRONGFUL DISCOURSE OR NOT?
The study was set to investigate the nature and effects of religious violence along with the governments' role in combating such violence. The study also intended to reveal the causes of the increasingly growing impact of religious violence. The study has been based on the rationale that radicalism and fundamentalism empower religious violence. The study employed the meta-analysis research method whereby the researchers carried out the synthesis of results from existent studies to reach conclusions and inferences that could address the study questions. The findings of the study indicated that the religious violence often prospers due to the anger that the public holds for the marginalization that should be eradicated. Religion ignites the anger and turns it into violence. The findings of the study showed that the economics of religion could be an approach based on the assumptions of stability, behavior, and preferences. The economic religious approach might be used rigorously to disseminate the fundamentals of religious violence. The portrayal of sects as militias and angry fanatics that are waging war against the enlightened and modern society made matters worse. Sects as a backbone of religious violence could flourish in communities that are different in culture and religion. It is recommended that governments adopt educational system and the strategy of organizing summits, dialogs, and commissions to give communities hope for a brighter future that could guarantee them and their posterity a happy, satisfying life in a setting where diversity and tolerance of all religions and cultures prevail. Article visualizations
Large-scale lateral saturated soil hydraulic conductivity as a metric for the connectivity of subsurface flow paths at hillslope scale
Lateral saturated soil hydraulic conductivity, Ks,l, is the soil property governing subsurface water transfer in hillslopes, and the key parameter in many numerical models simulating hydrological processes at the hillslope and catchment scales. Likewise, the hydrological connectivity of the lateral flow paths plays a significant role in determining the rate of the subsurface flow at various spatial scales. This study investigates the relationship between Ks,l and hydrological connectivity at the hillslope spatial scale. Ks,l was determined by the subsurface flow rates intercepted by drains and water table depths observed in a well network. The hydrological connectivity was evaluated by the synchronicity among water table peaks, and between these and the peaks of the drained flow. Rainfall and soil moisture were used to investigate the influence of the transient hydrological soil condition on connectivity and Ks,l. As the synchronicity of the water table response between wells increased, the lag times between the peaks of water levels and those of the drained subsurface flow decreased. Moreover, the most synchronic water table rises determined the highest drainage rates. The relationships between Ks,l and water table depths were highly non-linear, with a sharp increase in the values for water table levels close to the soil surface. Estimated Ks,l values for the full saturated soil were in the order of thousands of mm h−1, suggesting the activation of macropores in the root zone. The Ks,l values determined at the peak of the drainage events were correlated with the indicators of synchronicity. The sum of cumulative rainfall and antecedent soil moisture was correlated with the connectivity indicators and Ks,l. We suggest that, for simulating realistic processes at the hillslope scale, the hydrological connectivity could be implicitly considered in hydrological modelling through an evaluation of Ks,l at the same spatial scale
Matter Fields in the Lagrangian Loop Representation: Scalar QED
We present the extension of the Lagrangian loop gauge invariant
representation in such a way to include matter fields. The partition function
of lattice compact U(1)-Higgs model is expressed as a sum over closed as much
as open surfaces. We have simulated numerically the loop action equivalent to
the Villain form of the action and mapped out the beta-gamma phase diagram of
this model.Comment: 10 pages, LaTe
L-branes
The superembedding approach to -branes is used to study a class of
-branes which have linear multiplets on the worldvolume. We refer to these
branes as L-branes. Although linear multiplets are related to scalar multiplets
(with 4 or 8 supersymmetries) by dualising one of the scalars of the latter to
a -form field strength, in many geometrical situations it is the linear
multiplet version which arises naturally. Furthermore, in the case of 8
supersymmetries, the linear multiplet is off-shell in contrast to the scalar
multiplet. The dynamics of the L-branes are obtained by using a systematic
procedure for constructing the Green-Schwarz action from the superembedding
formalism. This action has a Dirac-Born-Infeld type structure for the -form.
In addition, a set of equations of motion is postulated directly in superspace,
and is shown to agree with the Green-Schwarz equations of motion.Comment: revised version, minor changes, references added, 22 pages, no
figures, LaTe
A remote sensing and modeling integrated approach for constructing continuous time series of daily actual evapotranspiration
Satellite remote sensing-based surface energy balance (SEB) techniques have emerged as useful tools for quantifying spatialized actual evapotranspiration at various temporal and spatial scales. However, discontinuous data acquisitions and/or gaps in image acquisition due to cloud cover can limit the applicability of satellite remote sensing (RS) in agriculture water management where continuous time series of daily crop actual evapotranspiration (ETc act) are more valued. The aim of the research is to construct continuous time series of daily ETc act starting from temporal estimates of actual evapotranspiration obtained by SEB modelling (ETa eb) on Landsat-TM images. SEBAL model was integrated with the FAO 56 evaporation model, RS-retrieved vegetative biomass dynamics (by NDVI) and on-field measurements of soil moisture and potential evapotranspiration. The procedure was validated by an eddy covariance tower on a vineyard with partial soil coverage in the south of Sardinia Island, Italy. The integrated modeling approach showed a good reproduction of the time series dynamics of observed ETc act (R2 =0.71, MAE=0.54 mm d-1, RMSE=0.73 mm d-1). A daily and a cumulative monthly temporal analysis showed the importance of integrating parameters that capture changes in the soil-plant-atmosphere (SPA) continuum between Landsat acquisitions. The comparison with daily ETc act obtained by the referenced ET fraction (ETrF) method that considers only weather variability (by ETo) confirmed the lead of the proposed procedure in the spring/early summer periods when vegetation biomass changes and soil water evaporation have a significant weight in the ET process. The applied modelling approach was also robust in constructing the missing ETc act data under scenarios of limited cloud-free Landsat acquisitions. The presented integrated approach has a great potential for the near real time monitoring and scheduling of irrigation practices. Further testing of this approach with diverse dataset and the integration with the soil water modeling is to be analyzed in future work
Pembrolizumab monotherapy for previously treated metastatic triple-negative breast cancer: cohort A of the phase II KEYNOTE-086 study
Immunoterapia; Pembrolizumab; neoplà sies mamà ries triple-negativesInmunoterapia; Pembrolizumab; neoplasias mamarias triple-negativasImmunotherapy; Pembrolizumab; triple-negative breast neoplasmsBackground: Treatment options for previously treated metastatic triple-negative breast cancer (mTNBC) are limited. In cohort A of the phase II KEYNOTE-086 study, we evaluated pembrolizumab as second or later line of treatment for patients with mTNBC. Patients and methods: Eligible patients had centrally confirmed mTNBC, ?1 systemic therapy for metastatic disease, prior treatment with anthracycline and taxane in any disease setting, and progression on or after the most recent therapy. Patients received pembrolizumab 200mg intravenously every 3 weeks for up to 2 years. Primary end points were objective response rate in the total and PD-L1–positive populations, and safety. Secondary end points included duration of response, disease control rate (percentage of patients with complete or partial response or stable disease for ?24 weeks), progression-free survival, and overall survival. Results: All enrolled patients (N¼170) were women, 61.8% had PD-L1–positive tumors, and 43.5% had received ?3 previous lines of therapy for metastatic disease. ORR (95% CI) was 5.3% (2.7–9.9) in the total and 5.7% (2.4–12.2) in the PD-L1–positive populations. Disease control rate (95% CI) was 7.6% (4.4–12.7) and 9.5% (5.1–16.8), respectively. Median duration of response was not reached in the total (range, 1.2þ–21.5þ) and in the PD-L1–positive (range, 6.3–21.5þ) populations. Median PFS was 2.0 months (95% CI, 1.9–2.0), and the 6-month rate was 14.9%. Median OS was 9.0 months (95% CI, 7.6–11.2), and the 6-month rate was 69.1%. Treatment-related adverse events occurred in 103 (60.6%) patients, including 22 (12.9%) with grade 3 or 4 AEs. There were no deaths due to AEs. Conclusions: Pembrolizumab monotherapy demonstrated durable antitumor activity in a subset of patients with previously treated mTNBC and had a manageable safety profile.This work was supported by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA
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