752 research outputs found
Generalized Propagation Channel Model for 2GHz Low Elevation Links Using a Ray-tracing Method
Unmanned Aerial Vehicles (UAV) will increasingly be used for responding to emergencies or for law enforcement in civil surveillance applications. Transferring the enormous amounts of information from UAV-mounted cameras or sensors will require large bandwidths, unlike the information required for remotely controlling a UAV, thus necessitating higher frequency bands typically in the vicinity of 2 or 5 GHz. Novel hardware developments will need to rely on a versatile propagation channel model for the envisaged scenarios ranging from deep shadow urban areas to open fields. This paper studies more complex intermediate scenarios, which fall between the aforementioned ones, and which are more difficult to model. A semi-deterministic model, first developed for open, flat areas, has been generalized to accommodate any possible operational scenario and was tested in built-up areas. The model involves a stochastic part and a determinist which is a ray-tracing based part used to compute the long term mean (LTM) of the signal's coherent component
L'évaluation de l'économie sociale, quelques enjeux de conceptualisation et de méthodologie
Ce texte vise à discuter d'un certain nombre d'enjeux qui se posent lorsqu'il est question d'évaluation des activités d'économie sociale (ÉS), notamment au plan des concepts et des méthodologies qui viennent en appui de l'évaluation. De plus, la contribution de l'ÉS à la démocratisation de l'économique fait que les enjeux de son évaluation se posent également en termes politiques. Afin de tenir compte de ces particularités de l'ÉS, la démarche d'évaluation doit donc déborder la seule perspective productiviste et ne pas se limiter à un cadre purement économique ou gestionnaire. L'évaluation est également l'un des lieux où s'exerce l'orientation et le contrôle des actions. Il s'agit donc d'un moment fort de la gouvernance des activités d'ÉS
Glandular areas associated with the male genitalia in Triatoma rubrofasciata (Triatominae, Reduviidae, Hemiptera) and other Reduviidae
A Model for the Detailed Analysis of Radio Links Involving Tree Canopies
Detailed analysis of tree canopy interaction with incident radiowaves has mainly been limited to remote sensing for the purpose of forest classification among many other applications. This represents a monostatic configuration, unlike the case of communication links, which are bistatic. In general, link analyses have been limited to the application of simple, empirical formulas based on the use of specific attenuation values in dB/m and the traversed vegetated mass as, e.g., the model in Recommendation ITU-R P.833-8 [1]. In remote sensing, two main techniques are used: Multiple Scattering Theory (MST) [2][5] and Radiative Transfer Theory (RT), [5] and [6]. We have paid attention in the past to MST [7][10]. It was shown that a full application of MST leads to very long computation times which are unacceptable in the case where we have to analyze a scenario with several trees. Extensive work using MST has been also presented by others in [11][16] showing the interest in this technique. We have proposed a simplified model for scattering from tree canopies based on a hybridization of MST and a modified physical optics (PO) approach [16]. We assume that propagation through a canopy is accounted for by using the complex valued propagation constant obtained by MST. Unlike the case when the full MST is applied, the proposed approach offers significant benefits including a direct software implementation and acceptable computation times even for high frequencies and electrically large canopies. The proposed model thus replaces the coherent component in MST, significant in the forward direction, but keeps the incoherent or diffuse scattering component present in all directions. The incoherent component can be calculated within reasonable times. Here, we present tests of the proposed model against MST using an artificial single-tree scenario at 2 GHz and 10 GHz
Manipulation of drugs to achieve the required dose is intrinsic to paediatric practice but is not supported by guidelines or evidence
Background: A lack of age-appropriate formulations can make it difficult to administer medicines to children. A manipulation of the dosage form may be required to achieve the required dose. This study aimed to describe medicines that are manipulated to achieve the required dose in paediatric practice.Method: A structured, undisguised observational study and postal survey. The observational study investigated drug manipulations occurring in clinical practice across three sites. The questionnaire, administered to a sample of paediatric nurses throughout the UK, surveyed manipulations conducted and nurses' experiences and views.Results: The observational study identified 310 manipulations, of which 62% involved tablets, 21% were intravenous drugs and 10% were sachets. Of the 54 observed manipulations 40 involved tablets with 65% of the tablets being cut and 30% dispersed to obtain a smaller dose. 188 manipulations were reported by questionnaire respondents, of these 46% involved tablets, 12% were intravenous drugs, and 12% were nebuliser solutions. Manipulations were predominantly, but not exclusively, identified in specialist clinical areas with more highly dependent patients. Questionnaire respondents were concerned about the accuracy of the dose achieved following manipulations and the lack of practice guidance.Conclusion: Manipulations to achieve the required dose occur throughout paediatric in-patient settings. The impact of manipulations on the efficacy of the drugs, the accuracy of the dose and any adverse effects on patients is not known. There is a need to develop evidence-based guidance for manipulations of medicines in children
Automatic Assessment of Speech Capability Loss in Disordered Speech
International audienceIn this article, we report on the use of an automatic technique to assess pronunciation in the context of several types of speech disorders. Even if such tools already exist, they are more widely used in a different context, namely, Computer-Assisted Language Learning, in which the objective is to assess nonnative pronunciation by detecting learners' mispronunciations at segmental and/or suprasegmental levels. In our work, we sought to determine if the Goodness of Pronunciation (GOP) algorithm, which aims to detect phone-level mispronunciations by means of automatic speech recognition, could also detect segmental deviances in disordered speech. Our main experiment is an analysis of speech from people with unilateral facial palsy. This pathology may impact the realization of certain phonemes such as bilabial plosives and sibilants. Speech read by 32 speakers at four different clinical severity grades was automatically aligned and GOP scores were computed for each phone realization. The highest scores, which indicate large dissimilarities with standard phone realizations, were obtained for the most severely impaired speakers. The corresponding speech subset was manually transcribed at phone level; 8.3% of the phones differed from standard pronunciations extracted from our lexicon. The GOP technique allowed the detection of 70.2% of mispronunciations with an equal rate of about 30% of false rejections and false acceptances. Finally, to broaden the scope of the study, we explored the correlation between GOP values and speech comprehensibility scores on a second corpus, composed of sentences recorded by six people with speech impairments due to cancer surgery or neurological disorders. Strong correlations were achieved between GOP scores and subjective comprehensibility scores (about 0.7 absolute). Results from both experiments tend to validate the use of GOP to measure speech capability loss, a dimension that could be used as a complement to physiological measures in pathologies causing speech disorders
Towards the growth of Cu2ZnSn1 xGexS4 thin films by a single stage process Effect of substrate temperature and composition
Cu2ZnSn1-xGexS4 (CZTGS) thin films prepared by flash evaporation of a Zn-rich Cu2ZnSn0.5Ge0.5S4 bulk compound in powder form, and a subsequent thermal annealing in S containing Ar atmosphere are studied. The effect of the substrate temperature during evaporation and the initial composition of the precursor powder on the growth mechanism and properties of the final CZTGS thin film are investigated. The microstructure of the films and elemental depth profiles depend strongly on the growth conditions used. Incorporation of Ge into the Cu2ZnSnS4 lattice is demonstrated by the shift of the relevant X-ray diffraction peaks and Raman vibrational modes towards higher diffraction angles and frequencies respectively. A Raman mode at around 348-351 cm-1 is identified as characteristic of CZTGS alloys for x = [Ge]/([Sn]+[Ge]) = 0.14-0.30. The supply of Ge enables the reduction of the Sn loss via a saccrifical Ge loss. This fact allows increasing the substrate temperature up to 350º C during the evaporation, forming a high quality kesterite material and therefore, reducing the deposition process to one single stageRC acknowledges financial support from Spanish MINECO within the Ramón y Cajal programme (RYC-2011-08521) and VIR for the Juan de la Cierva fellowship (JCI-2011-10782). GB also acknowledges the CSIC-JAE pre-doctoral program, co-funded by the European Social Fund. This work was supported by the Marie Curie-IRSES project (PVICOKEST, GA: 269167), Marie Curie-ITN project (KESTCELL, GA: 316488), DAAD project (INTERKEST, Ref: 57050358), and MINECO projects (SUNBEAM, ENE2013-49136-C4-3-R) (TEC2012-38901-C02-01). A. Scheu is acknowledged for GDOES measurement
MALT1 Small Molecule Inhibitors Specifically Suppress ABC-DLBCL In Vitro and In Vivo
SummaryMALT1 cleavage activity is linked to the pathogenesis of activated B cell-like diffuse large B cell lymphoma (ABC-DLBCL), a chemoresistant form of DLBCL. We developed a MALT1 activity assay and identified chemically diverse MALT1 inhibitors. A selected lead compound, MI-2, featured direct binding to MALT1 and suppression of its protease function. MI-2 concentrated within human ABC-DLBCL cells and irreversibly inhibited cleavage of MALT1 substrates. This was accompanied by NF-κB reporter activity suppression, c-REL nuclear localization inhibition, and NF-κB target gene downregulation. Most notably, MI-2 was nontoxic to mice, and displayed selective activity against ABC-DLBCL cell lines in vitro and xenotransplanted ABC-DLBCL tumors in vivo. The compound was also effective against primary human non-germinal center B cell-like DLBCLs ex vivo
Atypical carcinoid tumours of the lung: prognostic factors and patterns of recurrence
Background: Atypical carcinoids (AC) of the lung are rare intermediate-grade neuroendocrine neoplasms. Prognostic factors for these tumours are undefined. Methods: Our cooperative group retrieved data on 127 patients operated between 1980 and 2009 because of an AC. Several clinical and pathological features were studied. Results: In a univariable analysis, T-status (p=0.005), N-status (p=0.021), preoperative M-status (previously treated) (p=0.04), and distant recurrence developed during the outcome (p<0.001) presented statistically significant differences related to survival of these patients. In a multivariable analysis, only distant recurrence was demonstrated to be an independent risk factor for survival (p<0.001; HR: 13.1). During the monitoring, 25.2% of the patients presented some kind of recurrence. When we studied recurrence factors in a univariable manner, sublobar resections presented significant relationship with locoregional recurrence (p<0.001). In the case of distant recurrence, T and N status presented significant differences. Patients with preoperative M1 status presented higher frequencies of locoregional and distant recurrence (p=0.004 and p<0.001, respectively). In a multivariable analysis, sublobar resection was an independent prognostic factor to predict locoregional recurrence (p=0.002; HR: 18.1). Conclusions: Complete standard surgical resection with radical lymphadenectomy is essential for AC. Sublobar resections are related to locoregional recurrence, so they should be avoided except for carefully selected patients. Nodal status is an important prognostic factor to predict survival and recurrence. Distant recurrence is related to poor outcome
Metabolic and lipidomic profiling of steatotic human livers during ex situ normothermic machine perfusion guides resuscitation strategies
There continues to be a significant shortage of donor livers for transplantation. One impediment is the discard rate of fatty, or steatotic, livers because of their poor post-transplant function. Steatotic livers are prone to significant ischemia-reperfusion injury (IRI) and data regarding how best to improve the quality of steatotic livers is lacking. Herein, we use normothermic (37°C) machine perfusion in combination with metabolic and lipidomic profiling to elucidate deficiencies in metabolic pathways in steatotic livers, and to inform strategies for improving their function. During perfusion, energy cofactors increased in steatotic livers to a similar extent as non-steatotic livers, but there were significant deficits in anti-oxidant capacity, efficient energy utilization, and lipid metabolism. Steatotic livers appeared to oxidize fatty acids at a higher rate but favored ketone body production rather than energy regeneration via the tricyclic acid cycle. As a result, lactate clearance was slower and transaminase levels were higher in steatotic livers. Lipidomic profiling revealed ω-3 polyunsaturated fatty acids increased in non-steatotic livers to a greater extent than in steatotic livers. The novel use of metabolic and lipidomic profiling during ex situ normothermic machine perfusion has the potential to guide the resuscitation and rehabilitation of steatotic livers for transplantation
- …