29 resultados para Input-output analysis.
em Université de Lausanne, Switzerland
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In 1851 the French Social economist Auguste Ott discussed the problem of gluts and commercial crises, together with the issue of distributive justice between workers in co-operative societies. He did so by means of a 'simple reproduction scheme' sharing some features with modern intersectoral transactions tables, in particular in terms of their graphical representation. This paper presents Ott's theory of crises (which was based on the disappointment of expectations) and the context of his model, and discusses its peculiarities, supplying a new piece for the reconstruction of the prehistory of input-output analysis.
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The Agenda 21 for the Geneva region is the results from a broad consultation process including all local actors. The article 12 stipulates that « the State facilitates possible synergies between economic activities in order to minimize their environmental impacts » thus opening the way for Industrial Ecology (IE) and Industrial Symbiosis (IS). An Advisory Board for Industrial Ecology and Industrial Symbiosis implementation was established in 2002 involving relevant government agencies. Regulatory and technical conditions for IS are studied in the Swiss context. Results reveal that the Swiss law on waste does not hinder by-product exchanges. Methodology and technical factors including geographic, qualitative, quantitative and economical aspects are detailed. The competition with waste operators in a highly developed recycling system is also tackled.The IS project develops an empirical and systematic method for detecting and implementing by-products synergies between industrial actors disseminated throughout the Geneva region. Database management tool for the treatment of input-output analysis data and GIS tools for detecting potentials industrial partners are constantly improved. Potential symbioses for 17 flows (including energy, water and material flows) are currently studied for implementation.
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In the recent years, kernel methods have revealed very powerful tools in many application domains in general and in remote sensing image classification in particular. The special characteristics of remote sensing images (high dimension, few labeled samples and different noise sources) are efficiently dealt with kernel machines. In this paper, we propose the use of structured output learning to improve remote sensing image classification based on kernels. Structured output learning is concerned with the design of machine learning algorithms that not only implement input-output mapping, but also take into account the relations between output labels, thus generalizing unstructured kernel methods. We analyze the framework and introduce it to the remote sensing community. Output similarity is here encoded into SVM classifiers by modifying the model loss function and the kernel function either independently or jointly. Experiments on a very high resolution (VHR) image classification problem shows promising results and opens a wide field of research with structured output kernel methods.
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The molecular mechanisms that control how progenitors generate distinct subtypes of neurons, and how undifferentiated neurons acquire their specific identity during corticogenesis, are increasingly understood. However, whether postmitotic neurons can change their identity at late stages of differentiation remains unknown. To study this question, we developed an electrochemical in vivo gene delivery method to rapidly manipulate gene expression specifically in postmitotic neurons. Using this approach, we found that the molecular identity, morphology, physiology and functional input-output connectivity of layer 4 mouse spiny neurons could be specifically reprogrammed during the first postnatal week by ectopic expression of the layer 5B output neuron-specific transcription factor Fezf2. These findings reveal a high degree of plasticity in the identity of postmitotic neocortical neurons and provide a proof of principle for postnatal re-engineering of specific neural microcircuits in vivo.
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This guide introduces Data Envelopment Analysis (DEA), a performance measurement technique, in such a way as to be appropriate to decision makers with little or no background in economics and operational research. The use of mathematics is kept to a minimum. This guide therefore adopts a strong practical approach in order to allow decision makers to conduct their own efficiency analysis and to easily interpret results. DEA helps decision makers for the following reasons: - By calculating an efficiency score, it indicates if a firm is efficient or has capacity for improvement. - By setting target values for input and output, it calculates how much input must be decreased or output increased in order to become efficient. - By identifying the nature of returns to scale, it indicates if a firm has to decrease or increase its scale (or size) in order to minimize the average cost. - By identifying a set of benchmarks, it specifies which other firms' processes need to be analysed in order to improve its own practices.
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INTRODUCTION: Handwriting is a modality of language production whose cerebral substrates remain poorly known although the existence of specific regions is postulated. The description of brain damaged patients with agraphia and, more recently, several neuroimaging studies suggest the involvement of different brain regions. However, results vary with the methodological choices made and may not always discriminate between "writing-specific" and motor or linguistic processes shared with other abilities. METHODS: We used the "Activation Likelihood Estimate" (ALE) meta-analytical method to identify the cerebral network of areas commonly activated during handwriting in 18 neuroimaging studies published in the literature. Included contrasts were also classified according to the control tasks used, whether non-specific motor/output-control or linguistic/input-control. These data were included in two secondary meta-analyses in order to reveal the functional role of the different areas of this network. RESULTS: An extensive, mainly left-hemisphere network of 12 cortical and sub-cortical areas was obtained; three of which were considered as primarily writing-specific (left superior frontal sulcus/middle frontal gyrus area, left intraparietal sulcus/superior parietal area, right cerebellum) while others related rather to non-specific motor (primary motor and sensorimotor cortex, supplementary motor area, thalamus and putamen) or linguistic processes (ventral premotor cortex, posterior/inferior temporal cortex). CONCLUSIONS: This meta-analysis provides a description of the cerebral network of handwriting as revealed by various types of neuroimaging experiments and confirms the crucial involvement of the left frontal and superior parietal regions. These findings provide new insights into cognitive processes involved in handwriting and their cerebral substrates.
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Objective: Aim of post operative treatments after cardiac surgery is to avoid low cardiac output syndrome (LCOS). Levosimendan, a new inotrope agent, has been demonstrated in adult patient to be an effective treatment for this purpose when classical therapy is not effective. It shows a positive effect on cardiac output, with fewer adverse effects and lower mortality than with dopamine. There is very few data on its benefit in the paediatric population. The aim of this study is to evaluate the effect of levosimendan in cardiac children with LCOS.Methods: Retrospective analysis of 25 children hospitalised in our PICU after cardiac surgery that demonstrated LCOS not responding to classical catecholamine therapy and who received levosimendan as rescue. LCOS parameters like urine output, mixed venous oxygen saturation (SvO2), arterio-venous differences in CO2 (AVCO2) and plasmatic lactate were compared before therapy and at 12, 24, 48 and 72 hours after the beginning of the levosimendan infusion. We also analyzed the effect on the utilisation of amines (amine score), adverse events and mortality.Results: After the beginning of levosimendan infusion, urine output (3.1 vs 5.3ml/kg/h, p=0.003) and SVO2 (56 vs 64mmHg, p=0.001) increase significantly during first 72 hours and at the same time plasmatic lactate (2.6 vs 1.4 mmole/l, p<0.001), AVCO2 (11 vs 8 mmHg, p=0.002) and amine score (63 vs 39, p=0.007) decrease significantly. No side effects were noted during administration of levosimendan. In this group of patients, mortality was 0%.Conclusion: Levosimendan is an effective treatment in children after congenital heart surgery. Our study, with a greater sample of patient than other studies, confirms the improvement of cardiac output already shown in other paediatric studies.
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Background: The RCP is a 14 French collapsable percutaneous cardiovascular support device positioned in the descending part of the thoracic aorta via the femoral artery. A 10 patient first in man study demonstrated device safety and significant improvement in renal function among high risk PCI patients. We now report haemodynamic and renal efficacy in patients with ADHF.Methods: Prospective non randomised study seeking to recruit 20 patients with ADHF with a need for inotropic or mechanical circulatory support with: i) EF < 30% ii)Cardiac index(CI) < 2.2 L / min / m2 Outcome measures included: 1) Cardiac index (CI) 2) Pulmonary Capillary Wedge Pressure (PCWP) 3) Urine output / serum creatinine 4) Vascular / device complications 5) 30 day mortalityResults: INTERIM ANALYSIS (n=12) The mean age of the study group was 64 years, with a mean baseline creatinine of 193 umol/L, eGFR 38 ml/min. The intended RCP treatment period was 24 hours. During RCP treatment there was a significant mean reduction of PCWP at 4 hours of 17% (25 to 21 mmHg p=0.04). Mean CI increased at 12 hours by 11%, though not reaching significance (1.78 to 1.96 L/min/m2 p=0.08). RCP insertion prompted substantial diuresis. Urine output tripled over the first 12 hours compared to baseline (55 ml/hr vs 213 ml/hr p=0.03). This was associated with significantly improved renal function, a 28% reduction in serum creatinine at 12 hours (193 to 151 umol/L p=0.003), and a increase in eGFR from 38 ml/min to 50 ml/min (p=0.0007). 2 patients previously refused cardiac transplantation were reassessed and successfully transplanted within 9 months of RCP treatment on the basis of demonstrable renal reversibility. There were no vascular or device complications. There were 2 deaths at 30 days, one from multi-organ failure and sepsis, and one from intractable heart failure - neither were device related.Conclusion: RCP support in ADHF patients was associated with improved haemodynamics, and an improvement in renal function. The Reitan Catheter Pump may have a role in providing percutaneous cardiovascular and renal support in the acutely decompensated cardiac patient, and may have a role in suggesting renal reversibility in potential cardiac transplant patients. Further data will be reported at recruitment completion.
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The basal sliding surfaces in large rockslides are often composed of several surfaces and possess a complex geometry. The exact morphology and location in three dimensions of the sliding surface remains generally unknown, in spite of extensive field and subsurface investigations, such as those at the Åknes rockslide (western Norway). This knowledge is crucial for volume estimations, failure mechanisms, and numerical slope stability modeling. This paper focuses on the geomorphologic characterization of the basal sliding surface of a postglacial rockslide scar in the vicinity of Åknes. This scar displays a stepped basal sliding surface formed by dip slopes of the gneiss foliation linked together by steeply dipping fractures. A detailed characterization of the rockslide scar by means of high-resolution digital elevation models permits statistical parameters of dip angle, spacing, persistence, and roughness of foliation surfaces and step fractures to be obtained. The characteristics are used for stochastic simulations of stepped basal sliding surfaces at the Åknes rockslide. These findings are compared with previous models based on geophysical investigations. This study discusses the investigation of rockslide scars and rock outcrops for a better understanding of potential rockslides. This work identifies possible basal sliding surface locations, which is a valuable input for volume estimates, design and location of monitoring instrumentation, and numerical slope stability modeling.
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SUMMARY: Large sets of data, such as expression profiles from many samples, require analytic tools to reduce their complexity. The Iterative Signature Algorithm (ISA) is a biclustering algorithm. It was designed to decompose a large set of data into so-called 'modules'. In the context of gene expression data, these modules consist of subsets of genes that exhibit a coherent expression profile only over a subset of microarray experiments. Genes and arrays may be attributed to multiple modules and the level of required coherence can be varied resulting in different 'resolutions' of the modular mapping. In this short note, we introduce two BioConductor software packages written in GNU R: The isa2 package includes an optimized implementation of the ISA and the eisa package provides a convenient interface to run the ISA, visualize its output and put the biclusters into biological context. Potential users of these packages are all R and BioConductor users dealing with tabular (e.g. gene expression) data. AVAILABILITY: http://www.unil.ch/cbg/ISA CONTACT: sven.bergmann@unil.ch
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The hypothalamic damage induced by neonatal treatment with monosodium l-glutamate (MSG) induces several metabolic abnormalities, resulting in a rat hyperleptinemic-hyperadipose phenotype. This study was conducted to explore the impact of the neonatal MSG treatment, in the adult (120 days old) female rat on: (a) the in vivo and in vitro mineralocorticoid responses to ACTH and angiotensin II (AII); (b) the effect of leptin on ACTH- and AII-stimulated mineralocorticoid secretions by isolated corticoadrenal cells; and (c) abdominal adiposity characteristics. Our data indicate that, compared with age-matched controls, MSG rats displayed: (1) enhanced and reduced mineralocorticoid responses to ACTH and AII treatments, respectively, effects observed in both in vivo and in vitro conditions; (2) adrenal refractoriness to the inhibitory effect of exogenous leptin on ACTH-stimulated aldosterone output by isolated adrenocortical cells; and (3) distorted omental adiposity morphology and function. This study supports that the adult hyperleptinemic MSG female rat is characterized by enhanced ACTH-driven mineralocorticoid function, impaired adrenal leptin sensitivity, and disrupted abdominal adiposity function. MSG rats could counteract undesirable effects of glucocorticoid excess, by developing a reduced AII-driven mineralocorticoid function. Thus, chronic hyperleptinemia could play a protective role against ACTH-mediated allostatic loads in the adrenal leptin resistant, MSG female rat phenotype.
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Morphogens of the Wnt protein family are the secreted lipoglycoprotein ligands which initiate several pathways heavily involved in the coordination of various developmental stages of organisms in the majority of animal species. Deregulation of these pathways in the adult leads to formation and sustaining of multiple types of cancer. The latter notion is reinforced by the fact that the very discovery of the first Wnt ligand was due to its role as the causative factor of carcinogenic transformation (Nusse and Varmus, 1982). Nowadays our knowledge on Wnt signaling has "moved with the times" and these pathways were identified to be often crucial for tumor formation, its interactions with the microenvironment, and promotion of the metastases (Huang and Du, 2008; Zerlin et al., 2008; Jessen, 2009). Thus the relevance of the pathway as the target for drug development has further increased in the light of modern paradigms of the complex cancer treatments which target also spreading and growth- promoting factors of tumors by specific and highly efficient substances (Pavet et al., 2010). Presently the field of the Wnt-targeting drug research is almost solely dominated by assays based on transcriptional activation induced by the signaling. This approach resulted in development of a number of promising substances (Lee et al., 2011). Despite its effectiveness, the method nevertheless suffers from several drawbacks. Among the major ones is the fact that this approach is prone to identify compounds targeting rather downstream effectors of the pathway, which are indiscriminately used by all the subtypes of the Wnt signaling. Additionally, proteins which are involved in several signaling cascades and not just the Wnt pathway turn out as targets of the new compounds. These issues increase risks of side effects due to off-target interactions and blockade of the pathway in healthy cells. In the present work we put forward a novel biochemical approach for drug development on the Wnt pathway. It targets Frizzleds (Fzs) - a family of 7-transmbembrane proteins which serve as receptors for Wnt ligands. They offer unique properties for the development of highly specific and effective drugs as they control all branches of the Wnt signaling. Recent advances in the understanding of the roles of heterotrimeric G proteins downstream from Fzs (Katanaev et al., 2005; Liu et al., 2005; Jernigan et al., 2010) suggest application of enzymatic properties of these effectors to monitor the receptor-mediated events. We have applied this knowledge in practice and established a specific and efficient method based on utilization of a novel high-throughput format of the GTP-binding assay to follow the activation of Fzs. This type of assay is a robust and well-established technology for the research and screenings on the GPCRs (Harrison and Traynor, 2003). The conventional method of detection involves the radioactively labeled non-hydrolysable GTP analog [35S]GTPyS. Its application in the large-scale screenings is however problematic which promoted development of the novel non-radioactive GTP analog GTP-Eu. The new molecule employs phenomenon of the time-resolved fluorescence to provide sensitivity comparable to the conventional radioactive substance. Initially GTP-Eu was tested only in one of many possible types of GTP-binding assays (Frang et al., 2003). In the present work we expand these limits by demonstrating the general comparability of the novel label with the radioactive method in various types of assays. We provide a biochemical characterization of GTP-Eu interactions with heterotrimeric and small GTPases and a comparative analysis of the behavior of the new label in the assays involving heterotrimeric G protein effectors. These developments in the GTP-binding assay were then applied to monitor G protein activation by the Fz receptors. The data obtained in mammalian cultured cell lines provides for the first time an unambiguous biochemical proof for direct coupling of Fzs with G proteins. The specificity of this interaction has been confirmed by the experiments with the antagonists of Fz and by the pertussis toxin-mediated deactivation. Additionally we have identified the specificity of Wnt3a towards several members of the Fz family and analyzed the properties of human Fz-1 which was found to be the receptor coupled to the Gi/o family of G proteins. Another process playing significant role in the functioning of every GPCR is endocytosis. This phenomenon can also be employed for drug screenings on GPCRs (Bickle, 2010). In the present work we have demonstrated that Drosophila Fz receptors are involved in an unusual for many GPCRs manifestation of the receptor-mediated internalization. Through combination of biochemical approaches and studies on Drosophila as the model organism we have shown that direct interactions of the Fzs and the α-subunit of the heterotrimeric G protein Go with the small GTPase Rab5 regulate internalization of the receptor in early endosomes. We provide data uncovering the decisive role of this self-promoted endocytosis in formation of a proper signaling output in the canonical as well as planar cell polarity (PCP) pathways regulated by Fz. The results of this work thus establish a platform for the high-throughput screening to identify substances active in the cancer-related Wnt pathways. This methodology has been adjusted and applied to provide the important insights in Fz functioning and will be instrumental for further investigations on the Wnt-mediated pathways.
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BACKGROUND AND PURPOSE: A right-to-left shunt can be identified by contrast transcranial Doppler ultrasonography (c-TCD) at rest and/or after a Valsalva maneuver (VM) or by arterial blood gas (ABG) measurement. We assessed the influence of controlled strain pressures and durations during VM on the right-to-left passage of microbubbles, on which depends the shunt classification by c-TCD, and correlated it with the right-to-left shunt evaluation by ABG measurements in stroke patients with patent foramen ovale (PFO). METHODS: We evaluated 40 stroke patients with transesophageal echocardiography-documented PFO. The microbubbles were recorded with TCD at rest and after 4 different VM conditions with controlled duration and target strain pressures (duration in seconds and pressure in cm H2O, respectively): V5-20, V10-20, V5-40, and V10-40. The ABG analysis was performed after pure oxygen breathing in 34 patients, and the shunt was calculated as percentage of cardiac output. RESULTS: Among all VM conditions, V5-40 and V10-40 yielded the greatest median number of microbubbles (84 and 95, respectively; P<0.01). A significantly larger number of microbubbles were detected in V5-40 than in V5-20 (P<0.001) and in V10-40 than in V10-20 (P<0.01). ABG was not sensitive enough to detect a shunt in 31 patients. CONCLUSIONS: The increase of VM expiratory pressure magnifies the number of microbubbles irrespective of the strain duration. Because the right-to-left shunt classification in PFO is based on the number of microbubbles, a controlled VM pressure is advised for a reproducible shunt assessment. The ABG measurement is not sensitive enough for shunt assessment in stroke patients with PFO.
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In this paper we study the relevance of multiple kernel learning (MKL) for the automatic selection of time series inputs. Recently, MKL has gained great attention in the machine learning community due to its flexibility in modelling complex patterns and performing feature selection. In general, MKL constructs the kernel as a weighted linear combination of basis kernels, exploiting different sources of information. An efficient algorithm wrapping a Support Vector Regression model for optimizing the MKL weights, named SimpleMKL, is used for the analysis. In this sense, MKL performs feature selection by discarding inputs/kernels with low or null weights. The approach proposed is tested with simulated linear and nonlinear time series (AutoRegressive, Henon and Lorenz series).