Showing papers by "ParisTech published in 2015"
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TL;DR: Active gel physics as discussed by the authors is a field that has emerged in recent years to fill this gap and is underpinned by a theory that takes into account the transduction of chemical energy on the molecular scale.
Abstract: The mechanical behaviour of cells is largely controlled by a structure that is fundamentally out of thermodynamic equilibrium: a network of crosslinked filaments subjected to the action of energy-transducing molecular motors. The study of this kind of active system was absent from conventional physics and there was a need for both new theories and new experiments. The field that has emerged in recent years to fill this gap is underpinned by a theory that takes into account the transduction of chemical energy on the molecular scale. This formalism has advanced our understanding of living systems, but it has also had an impact on research in physics per se. Here, we describe this developing field, its relevance to biology, the novelty it conveys to other areas of physics and some of the challenges in store for the future of active gel physics. Equilibrium physics is ill-equipped to explain all of life’s subtleties, largely because living systems are out of equilibrium. Attempts to overcome this problem have given rise to a lively field of research—and some surprising biological findings.
611 citations
TL;DR: Two distinct subsets of dopamine neurons in the fly brain signal reward for short-term (STM) and long-term memories (LTM), and a single type of dopamine neuron is identified that conveys the reward signal to restricted subdomains of the mushroom body lobes and induces long- term memory.
Abstract: Drosophila melanogaster can acquire a stable appetitive olfactory memory when the presentation of a sugar reward and an odor are paired. However, the neuronal mechanisms by which a single training induces long-term memory are poorly understood. Here we show that two distinct subsets of dopamine neurons in the fly brain signal reward for short-term (STM) and long-term memories (LTM). One subset induces memory that decays within several hours, whereas the other induces memory that gradually develops after training. They convey reward signals to spatially segregated synaptic domains of the mushroom body (MB), a potential site for convergence. Furthermore, we identified a single type of dopamine neuron that conveys the reward signal to restricted subdomains of the mushroom body lobes and induces long-term memory. Constant appetitive memory retention after a single training session thus comprises two memory components triggered by distinct dopamine neurons.
195 citations
TL;DR: In this article, the authors present an overview of the state of the art on the research on dynamic line rating forecasting, which is directed at researchers and decision makers in the renewable energy and smart grids domain, and in particular at members of both the power system and meteorological community.
Abstract: This paper presents an overview of the state of the art on the research on Dynamic Line Rating forecasting. It is directed at researchers and decision-makers in the renewable energy and smart grids domain, and in particular at members of both the power system and meteorological community. Its aim is to explain the details of one aspect of the complex interconnection between the environment and power systems. The ampacity of a conductor is defined as the maximum constant current which will meet the design, security and safety criteria of a particular line on which the conductor is used. Dynamic Line Rating (DLR) is a technology used to dynamically increase the ampacity of electric overhead transmission lines. It is based on the observation that the ampacity of an overhead line is determined by its ability to dissipate into the environment the heat produced by Joule effect. This in turn is dependent on environmental conditions such as the value of ambient temperature, solar radiation, and wind speed and direction. Currently, conservative static seasonal estimations of meteorological values are used to determine ampacity. In a DLR framework, the ampacity is estimated in real time or quasi-real time using sensors on the line that measure conductor temperature, tension, sag or environmental parameters such as wind speed and air temperature. Because of the conservative assumptions used to calculate static seasonal ampacity limits and the variability of weather parameters, DLRs are considerably higher than static seasonal ratings. The latent transmission capacity made available by DLRs means the operation time of equipment can be extended, especially in the current power system scenario, where power injections from Intermittent Renewable Sources (IRS) put stress on the existing infrastructure. DLR can represent a solution for accommodating higher renewable production whilst minimizing or postponing network reinforcements. On the other hand, the variability of DLR with respect to static seasonal ratings makes it particularly difficult to exploit, which explains the slow take-up rate of this technology. In order to facilitate the integration of DLR into power system operations, research has been launched into DLR forecasting, following a similar avenue to IRS production forecasting, i.e. based on a mix of statistical methods and meteorological forecasts. The development of reliable DLR forecasts will no doubt be seen as a necessary step for integrating DLR into power system management and reaping the expected benefits.
122 citations
TL;DR: An integrated experimental framework is developed that extends the brain exploration capabilities of functional ultrasound imaging to awake and mobile rats and allows parallel access to electroencephalography recordings of neuronal activity.
Abstract: We developed an integrated experimental framework that extends the brain exploration capabilities of functional ultrasound imaging to awake and mobile rats. In addition to acquiring hemodynamic data, this method further allows parallel access to electroencephalography (EEG) recordings of neuronal activity. We illustrate this approach with two proofs of concept: a behavioral study on theta rhythm activation in a maze running task and a disease-related study on spontaneous epileptic seizures.
116 citations
TL;DR: In this article, the residual stress distribution induced by laser shock processing in a 2050-T8 aeronautical aluminium alloy with both X-ray diffraction measurements and 3D finite element simulation is investigated.
115 citations
TL;DR: A bi-objective optimization model for designing a closed loop supply chain (CLSC) network under uncertainty in which the total costs and the maximum waiting times in the queue of products are considered to minimize.
115 citations
TL;DR: The theoretically derived transition threshold yields an excellent agreement with experimental data and a closed-form expression for the size of the droplets generated in the step-emulsification regime and derived using geometric arguments also shows a very good agreement with the experiment.
Abstract: We present a comprehensive study of the step-emulsification process for high-throughput production of colloidal monodisperse droplets. The ‘microfluidic step emulsifier’ combines a shallow microchannel operating with two co-flowing immiscible fluids and an abrupt (step-like) opening to a deep and wide reservoir. Based on Hele-Shaw hydrodynamics, we determine the quasi-static shape of the fluid interface prior to transition to oscillatory step-emulsification at low capillary numbers. The theoretically derived transition threshold yields an excellent agreement with experimental data. A closed-form expression for the size of the droplets generated in the step-emulsification regime and derived using geometric arguments also shows a very good agreement with the experiment.
106 citations
TL;DR: It was showed that although HR was associated with higher complication rate and longer hospital-stay, HR is proposed as the first-line treatment rather than RFA for patients with HCCs larger than 2 cm, and RFA may be an alternative to HR because of their comparable long-term efficacy.
Abstract: We performed a meta-analysis to evaluate the therapeutic effects of radiofrequency ablation (RFA) and surgical hepatic resection (HR) in the treatment of small hepatocellular carcinoma (HCC). Thirty-one studies were included in the analysis. A total of 16,103 patients were involved: 8,252 treated with RFA and 7,851 with HR. Compared to the RFA group, the 3, 5-year overall and disease-free survival rates in the HR group were significantly higher. On the other hand, complications were significantly fewer and hospital-stay was significantly shorter in the RFA group than in the HR group. In subgroup analyses, the overall and disease-free survival in the HR group were also significantly higher than those in the RFA group for HCCs ≤ 3 cm, whereas there were no significant differences between the two groups for HCCs ≤ 2 cm. Our analysis showed that although HR was associated with higher complication rate and longer hospital-stay, HR is proposed as the first-line treatment rather than RFA for patients with HCCs larger than 2 cm. For patients with HCCs of 2 cm or less, RFA may be an alternative to HR because of their comparable long-term efficacy.
83 citations
TL;DR: Recent data implicating chromatin regulators in cancer initiation and progression offers a promising avenue to develop new tools to help guide clinical decisions.
67 citations
TL;DR: In this article, the authors present an analysis of the current situation and existing potentials for future expansion in the residential sector of the European Union and discuss a series of strategies and policy measures that can be adopted to overcome existing barriers to market development.
58 citations
TL;DR: The results show that in the olfactory bulb, connexin 43 hemichannel function is promoted by neuronal activity and, in turn, modulates neuronal network slow oscillations, suggesting a novel mechanism of neuroglial interaction that could influenceOlfactory information processing by directly impacting the output of the o aroma bulb.
Abstract: An emergent concept in neurosciences consists in considering brain functions as the product of dynamic interactions between neurons and glial cells, particularly astrocytes. Although the role played by astrocytes in synaptic transmission and plasticity is now largely documented, their contribution to neuronal network activity is only beginning to be appreciated. In mouse olfactory bulb slices, we observed that the membrane potential of mitral cells oscillates between UP and DOWN states at a low frequency (<1 Hz). Such slow oscillations are correlated with glomerular local field potentials, indicating spontaneous local network activity. Using a combination of genetic and pharmacological tools, we showed that the activity of astroglial connexin 43 hemichannels, opened in an activity-dependent manner, increases UP state amplitude and impacts mitral cell firing rate. This effect requires functional adenosine A1 receptors, in line with the observation that ATP is released via connexin 43 hemichannels. These results highlight a new mechanism of neuroglial interaction in the olfactory bulb, where astrocyte connexin hemichannels are both targets and modulators of neuronal circuit function.
SIGNIFICANCE STATEMENT An emergent concept in neuroscience consists in considering brain function as the product of dynamic interactions between neurons and glial cells, particularly astrocytes. A typical feature of astrocytes is their high expression level of connexins, the molecular constituents of gap junction channels and hemichannels. Although hemichannels represent a powerful medium for intercellular communication between astrocytes and neurons, their function in physiological conditions remains largely unexplored. Our results show that in the olfactory bulb, connexin 43 hemichannel function is promoted by neuronal activity and, in turn, modulates neuronal network slow oscillations. This novel mechanism of neuroglial interaction could influence olfactory information processing by directly impacting the output of the olfactory bulb.
TL;DR: It is found that sleep-promoting VLPO neurons integrate energetic signals such as ambient glucose directly to regulate vigilance states accordingly and should be involved in the drowsiness that one feels after a high-sugar meal.
Abstract: Sleep-active neurons located in the ventrolateral preoptic nucleus (VLPO) play a crucial role in the induction and maintenance of slow-wave sleep (SWS). However, the cellular and molecular mechanisms responsible for their activation at sleep onset remain poorly understood. Here, we test the hypothesis that a rise in extracellular glucose concentration in the VLPO can promote sleep by increasing the activity of sleep-promoting VLPO neurons. We find that infusion of a glucose concentration into the VLPO of mice promotes SWS and increases the density of c-Fos-labeled neurons selectively in the VLPO. Moreover, we show in patch-clamp recordings from brain slices that VLPO neurons exhibiting properties of sleep-promoting neurons are selectively excited by glucose within physiological range. This glucose-induced excitation implies the catabolism of glucose, leading to a closure of ATP-sensitive potassium ( K ATP ) channels. The extracellular glucose concentration monitors the gating of K ATP channels of sleep-promoting neurons, highlighting that these neurons can adapt their excitability according to the extracellular energy status. Together, these results provide evidence that glucose may participate in the mechanisms of SWS promotion and/or consolidation. SIGNIFICANCE STATEMENT Although the brain circuitry underlying vigilance states is well described, the molecular mechanisms responsible for sleep onset remain largely unknown. Combining in vitro and in vivo experiments, we demonstrate that glucose likely contributes to sleep onset facilitation by increasing the excitability of sleep-promoting neurons in the ventrolateral preoptic nucleus (VLPO). We find here that these neurons integrate energetic signals such as ambient glucose directly to regulate vigilance states accordingly. Glucose-induced excitation of sleep-promoting VLPO neurons should therefore be involved in the drowsiness that one feels after a high-sugar meal. This novel mechanism regulating the activity of VLPO neurons reinforces the fundamental and intimate link between sleep and metabolism.
TL;DR: It is reported that BRD4, already identified as a target in several tumor models, is a new potential target in high grade non‐BRCAness ovarian carcinoma.
Abstract: The treatment of epithelial ovarian cancer (EOC) is narrowly focused despite the heterogeneity of this disease in which outcomes remain poor. To stratify EOC patients for targeted therapy, we developed an approach integrating expression and genomic analyses including the BRCAness status. Gene expression and genomic profiling were used to identify genes recurrently (>5%) amplified and overexpressed in 105 EOC. The LST (Large-scale State Transition) genomic signature of BRCAness was applied to define molecular subgroups of EOC. Amplified/overexpressed genes clustered mainly in 3q, 8q, 19p and 19q. These changes were generally found mutually exclusive. In the 85 patients for which the genomic signature could be determined, genomic BRCAness was found in 52 cases (61.1%) and non-BRCAness in 33 (38.8%). A striking mutual exclusivity was observed between BRCAness and amplification/overexpression data. Whereas 3q and 8q alterations were preferentially observed in BRCAness EOC, most alterations on chromosome 19 were in non-BRCAness cases. CCNE1 (19q12) and BRD4 (19p13.1) amplification/overexpression was found in 19/33 (57.5%) of non-BRCAness cases. Such disequilibrium was also found in the TCGA EOC data set used for validation. Potential target genes are frequently amplified/overexpressed in non-BRCAness EOC. We report that BRD4, already identified as a target in several tumor models, is a new potential target in high grade non-BRCAness ovarian carcinoma.
TL;DR: The present systematic review and meta-analysis confirms the potential value of a selected set of salivary biomarkers as diagnostic tools for head and neck carcinoma.
TL;DR: In the analysis of slip transfer, the emphasis is placed on twin boundaries (TBs) for which the dislocation reactions during slip transfer are analysed theoretically, experimentally and using the results of atomic molecular simulations published in the literature.
Abstract: The size and the character (low and large angle, special boundaries, tilt and twist boundaries, twins) of the grain boundaries (GBs) in polycrystalline materials influence their strength and their fracture toughness. Recent studies devoted to nanocrystalline (NC) materials have shown a deviation from the Hall–Petch law. Special GBs formed by Σ3 twins in face-centred cubic metals are also known to have a strong effect on the mechanical behaviour of these metals, in particular their work-hardening rate. Grain orientation influences also crack path, the fracture toughness of body-centred cubic (BCC) metals and the fatigue crack growth rate of microstructurally short cracks. This paper deals both with slip transfer at GBs and with the interactions between propagating cracks with GBs. In the analysis of slip transfer, the emphasis is placed on twin boundaries (TBs) for which the dislocation reactions during slip transfer are analysed theoretically, experimentally and using the results of atomic molecular simulations published in the literature. It is shown that in a number of situations this transfer leads to a normal motion of the TB owing to the displacement of partial dislocations along the TB. This motion can generate a de-twinning effect observed in particular in NC metals. Crack propagation across GBs is also considered. It is shown that cleavage crack path behaviour in BCC metals is largely dependent on the twist component of the GBs. A mechanism for the propagation of these twisted cracks involving a segmentation of the crack front and the existence of intergranular parts is discussed and verified for a pressure vessel steel. A similar segmentation seems to occur for short fatigue cracks although, quite surprisingly, this crossing mechanism for fatigue cracks does not seem to have been examined in very much detail in the literature. Metallurgical methods used to improve the strength of the materials, via grain boundaries, are briefly discussed.
TL;DR: In this paper, the authors used an elastic-viscoplastic constitutive relation for a progressively cavitating solid with two populations of void nucleating second phase particles to model the variation of ductile crack growth resistance and fracture surface roughness with loading rate under mode I plane strain, small scale yielding conditions.
Abstract: The variation of ductile crack growth resistance and fracture surface roughness with loading rate is modeled under mode I plane strain, small scale yielding conditions. Three-dimensional calculations are carried out using an elastic–viscoplastic constitutive relation for a progressively cavitating solid with two populations of void nucleating second phase particles. Larger inclusions that result in void nucleation at an early stage are modeled as discrete void nucleation sites while smaller particles that require large strains to nucleate voids are homogeneously distributed. The calculations are carried out for two values of density of the larger inclusions, 3.6% and 7.1%, and for prescribed loading rates K I ranging from 1 × 10 5 MPa m s − 1 to 5 × 10 7 MPa m s − 1 . The ductile fracture mode is found to undergo a transition from one that can be regarded as growth of a dominant main crack at the lower loading rates to one dominated by damage nucleation and micro-cracking ahead of the main crack at the higher loading rates. The values of JIC, the tearing modulus, TR, the total plastic dissipation and the plastic dissipation in the fracture process region are all found to increase with increasing loading rate. However, the ratio of plastic dissipation in the fracture process region to total plastic dissipation decreases with increasing prescribed loading rate. The fracture surfaces are found to display two self-affine regimes, with a Hurst exponent β ≈ 0.60 at small length scales and with β ≈ 0.45 at larger length scales. The multi-fractal spectra indicate multi-affine behavior in most cases but a range of loading rates and length scales exhibiting mono-affine behavior is also found. Parameters characterizing the fracture surface statistics, including the length scale at which a transition from a power law tail to an exponential tail occurs, are related to the mode of crack growth/damage accumulation. A linear relation is found between the values of JIC and TR and the saturation value of the correlation function of the surface roughness for K I 3 × 10 7 MPa m s − 1 .
TL;DR: In this article, the authors provide an extensive review to investigate the application of a special data mining technique, namely support vector machine (SVM), to deal with quality assessment problems in manufacturing.
Abstract: In many modern manufacturing industries, data that characterize the manufacturing process are electronically collected and stored in databases. Due to advances in data collection systems and analysis tools, data mining (DM) has widely been applied for quality assessment (QA) in manufacturing industries. In DM, the choice of technique to be used in analyzing a dataset and assessing the quality depend on the understanding of the analyst. On the other hand, with the advent of improved and efficient prediction techniques, there is a need for an analyst to know which tool performs better for a particular type of dataset. Although a few review papers have recently been published to discuss DM applications in manufacturing for QA, this paper provides an extensive review to investigate the application of a special DM technique, namely support vector machine (SVM) to deal with QA problems. This review provides a comprehensive analysis of the literature from various points of view as DM concepts, data preprocessing, DM applications for each quality task, SVM preliminaries, and application results. Summary tables and figures are also provided besides to the analyses. Finally, conclusions and future research directions are provided.
TL;DR: The ability to obtain precise data on implant orientation according to the patient posture opens new perspectives for a comprehensive analysis of the pelvic frontal and sagittal balance and its potential impact on implants function and failures.
Abstract: More total hip arthroplasty (THA) is performed worldwide and especially in younger and more active patients compared to earlier decades. One of the focuses of THA research in the future will be on optimizing the radiological follow-up of these patients using 2D and 3D measurements of implants position while reducing the radiation dose delivered.
Low-dose EOS® imaging is an innovative slot-scanning radiograph system providing valuable information in patient functional positions (standing, sitting and even squatting positions). EOS has been proven accurate and reliable without significant inconvenience caused by the metallic artifacts of implants. The ability to obtain precise data on implant orientation according to the patient posture opens new perspectives for a comprehensive analysis of the pelvic frontal and sagittal balance and its potential impact on implants function and failures.
We report our 8 years experience on our first 300 THA patients using this technology routinely for pre and post op evaluation. Our results will be compared and confronted with the actual literature about this innovative technology. We shall especially emphasize our experience about patients with abnormal posture and the evolution of the subject over time, because the phenomenon of an aging spine is frequently associated with the process of aging hips.
TL;DR: A novel distance-based decision model for the multi-attributes analysis by considering the concepts of intuitionistic fuzzy sets (IFSs), grey relations and compromise ratio approaches is introduced.
TL;DR: In this article, the effect of inertia and strain rate sensitivity of three materials under cavitation hydrodynamic impact has been studied in details by using finite element simulations, and it is found that if the impact duration is very short compared to a characteristic time of the material based on its natural frequency, no pit would form into the material even if a high impact stress is very high.
TL;DR: A hybrid multi-objective metaheuristic algorithm, namely multi-Objective invasive weed optimization (MOIWO), is developed for the given problem and a hybrid solution approach is utilized based on inexact programming, interval-valued fuzzy programming and rough interval programming to solve the model.
Abstract: This article proposes a multi-objective mixed-integer model to optimize the location of hubs within a hub network design problem under uncertainty. The considered objectives include minimizing the maximum accumulated travel time, minimizing the total costs including transportation, fuel consumption and greenhouse emissions costs, and finally maximizing the minimum service reliability. In the proposed model, it is assumed that for connecting two nodes, there are several types of arc in which their capacity, transportation mode, travel time, and transportation and construction costs are different. Moreover, in this model, determining the capacity of the hubs is part of the decision-making procedure and balancing requirements are imposed on the network. To solve the model, a hybrid solution approach is utilized based on inexact programming, interval-valued fuzzy programming and rough interval programming. Furthermore, a hybrid multi-objective metaheuristic algorithm, namely multi-objective invasive weed opti...
TL;DR: In this article, the residual stress was calculated using the Stoney formula and a rough surface based on pyramidal morphology was obtained for CrN, VN and VN.
Abstract: This work aims to show the characterisation of Cr–V–N coatings, with the varied amounts of Cr and V. CrN, VN and Cr–V–N coatings were deposited onto silicon and XC100 steel substrates by reactive radio frequency magnetron sputtering and characterised with X-ray diffraction, X-ray photoelectron spectroscopies, energy dispersive X-ray spectroscopy, scanning electron microscopy, nanoindentation, pin on disc tribological tests and scratch tests. The residual stress was calculated using the Stoney formula. Compared to the CrN system, the Cr–V–N films presented a rough surface based on pyramidal morphology. A hardness of 19·53 GPa and a friction coefficient of 0·55 were obtained for CrN; in contrast, Cr–V–N coatings presented a weak hardness of 6·23 GPa. In the case of wear against a 100Cr6 ball, the Cr–V–N films were completely removed from the substrate, even though the Cr–V–N coating presented a low friction coefficient (0·39). However, the VN film showed good tribological performance.
TL;DR: Results suggest that although both systems may require free histidine, they use different strategies to import nickel, and that l-histidine has a high positive impact on nickel import via the Cnt system.
Abstract: Staphylococcus aureus possesses two canonical ABC-importers dedicated to nickel acquisition: the NikABCDE and the CntABCDF systems, active under different growth conditions. This study reports on the extracytoplasmic nickel-binding components SaNikA and SaCntA. We showed by protein crystallography that SaNikA is able to bind either a Ni-(l-His)2 complex or a Ni-(l-His) (2-methyl-thiazolidine dicarboxylate) complex, depending on their availability in culture supernatants. Native mass spectrometry experiments on SaCntA revealed that it binds the Ni(ii) ion via a different histidine-dependent chelator but it cannot bind Ni-(l-His)2. In vitro experiments are consistent with in vivo nickel content measurements that showed that l-histidine has a high positive impact on nickel import via the Cnt system. These results suggest that although both systems may require free histidine, they use different strategies to import nickel.
TL;DR: In this paper, a new optimisation framework for process inspection planning of a manufacturing system with multiple quality characteristics, in which the proposed framework is based on a mixed-integer mathematical programming (MILP) model.
Abstract: This study develops a new optimisation framework for process inspection planning of a manufacturing system with multiple quality characteristics, in which the proposed framework is based on a mixed-integer mathematical programming (MILP) model. Due to the stochastic nature of production processes and since their production processes are sensitive to manufacturing variations; a proportion of products do not conform the design specifications. A common source of these variations is maladjustment of each operation that leads to a higher number of scraps. Therefore, uncertainty in maladjustment is taken into account in this study. A twofold decision is made on the subject that which quality characteristic needs what kind of inspection, and the time this inspection should be performed. To cope with the introduced uncertainty, two robust optimisation methods are developed based on Taguchi and Monte Carlo methods. Furthermore, a genetic algorithm is applied to the problem to obtain near-optimal solutions. To vali...
Abstract: This essay is concerned with the planning and densification of suburbs, which present a huge challenge insofar as they form a large area of urbanized land that remains underexploited due to low residential density. Drawing on current research in the Paris city-region, the essay focuses specifically on the difficulty in implementing densification policies in low-rise suburban areas. It examines the varying degrees of densification fostered by these policies, and builds upon recent urban studies literature on suburban change to trace how suburban areas are being transformed through regulations, instruments and market dynamics associated with densification processes. What kinds of densification policy are being implemented and what are the socio-economic, political and cultural determinants of each type of regulatory approach? This essay will attempt to answer this question via an analysis of the densification policies being put in place in the municipalities of the Paris city-region. It will offer in turn a typology of these different policies. It shows that densification is an instrument that can be used to address local political concerns which vary greatly depending on the economic, social and geographical position of municipalities within larger urban areas.
01 Nov 2015
TL;DR: In this article, the approches cognitives peuvent aider au renouvellement des paradigmes gestionnaires, i.e., a reenvisager and approfondir l’analyse des processus d'apprentissage collectifs.
Abstract: Les approches cognitives peuvent aider au renouvellement des paradigmes gestionnaires. Elles peuvent en particulier conduire a reenvisager et approfondir l’analyse des processus d’apprentissage collectifs. Ainsi permettent-elles, comme le montre l’auteur, notamment en distinguant systemes d’aide a la decision et systemes d’aide a la conception, de s’interroger sur des evolutions a venir, telles que l’emergence d’une « nouvelle ingenierie de la conception » et la multiplication d’experiences d’« autonomies ».
TL;DR: This study points out the limitations of 2D measurements of femoral offset on standard plane X-rays and suggests the EOS imaging system could be an option for obtaining accurate and reliable offset measurements while significantly limiting the patient’s exposure to radiation.
Abstract: Accurate evaluation of femoral offset is difficult with conventional anteroposterior (AP) X-rays. The EOS imaging system is a system that makes the acquisition of simultaneous and orthogonal AP and lateral images of the patient in the standing position possible. These two-dimensional (2D) images are equivalent to standard plane X-rays. Three-dimensional (3D) reconstructions are obtained from these paired images according to a validated protocol. This prospective study explores the value of the EOS imaging system for comparing measurements of femoral offset from these 2D images and the 3D reconstructions. We included 110 patients with unilateral total hip arthroplasty (THA). The 2D offset was measured on the AP view with the same protocol as for standard X-rays. The 3D offset was calculated from the reconstructions based on the orthogonal AP and lateral views. Reproducibility and repeatability studies were conducted for each measurement. We compared the 2D and 3D offset for both hips (with and without THA). For the global series (110 hips with and 110 without THA), 2D offset was 40 mm (SD 7.3; 7–57 mm). The standard deviation was 6.5 mm for repeatability and 7.5 mm for reproducibility. Three-dimensional offset was 43 mm (SD 6.6; 22–62 mm), with a standard deviation of 4.6 for repeatability and 5.5 for reproducibility. Two-dimensional offset for the hips without THA was 40 mm (SD 7.0; 26–56 mm), and 3D offset 43 mm (SD 6.6; 28–62 mm). For THA side, 2D offset was 41 mm (SD 8.2; 7–57 mm) and 3D offset 45 mm (SD 4.8; 22–61 mm). Comparison of the two protocols shows a significant difference between the 2D and 3D measurements, with the 3D offset having higher values. Comparison of the side with and without surgery for each case showed a 5-mm deficit for the offset in 35 % of the patients according to the 2D measurement but in only 26 % according to the 3D calculation. This study points out the limitations of 2D measurements of femoral offset on standard plane X-rays. The reliability of the EOS 3D models has been previously demonstrated with CT scan reconstructions as a reference. The EOS imaging system could be an option for obtaining accurate and reliable offset measurements while significantly limiting the patient’s exposure to radiation.
TL;DR: The Cancun conference decided to establish a Climate Green Fund (CGF) to help developing countries align their development policies with the long-term UNFCCC objectives as discussed by the authors.
Abstract: The Cancun conference decided to establish a Climate Green Fund (CGF) to help developing countries align their development policies with the long-term UNFCCC objectives. This paper clarifies the links between the two underlying motives: the first, technical in nature, is the necessity to redirect the infrastructure instruments in these countries (energy, transportation, building, material transformation industry) to avoid lock-in in carbon-intensive pathways in the likely absence of a significant world carbon price in the coming decade; the second, political in nature, is the interpretation of the CGF as a practical translation of the notion of the common but differentiated responsibility principle, since the funds are expected to come from Annex 1 countries. This paper shows why this latter perspective might generate some distrust given the orders of magnitude of funds to be levied in Annex 1 countries especially in the context of the financial crisis and major constraints on public budgets. It then explores the basic principles around which it is possible to minimize these risks by upgrading climate finance in the broader context of the evolution of the financial and monetary systems. After exploring how such links could help make climate policies that contribute to reducing some of the imbalances caused by economic globalization by reorienting world savings and reducing investment uncertainty, it sketches how this perspective might be palatable for the OECD, the major emerging economies and fossil fuel exporters.
TL;DR: In this article, the authors thank the Directorate for Research and Community Service of the Ministry of National Education for the Republic of Indonesia for the research grant, which was provided by the University of Singapore.
TL;DR: It is demonstrated that 220-kHz ultrasound is capable of inducing a thermal lesion in the brain of living swines without hemorrhage and may be safer, and the threshold established in this work may allow for the detection and prevention of deleterious cavitations.
Abstract: OBJECT In biological tissues, it is known that the creation of gas bubbles (cavitation) during ultrasound exposure is more likely to occur at lower rather than higher frequencies. Upon collapsing, such bubbles can induce hemorrhage. Thus, acoustic inertial cavitation secondary to a 220-kHz MRI-guided focused ultrasound (MRgFUS) surgery is a serious safety issue, and animal studies are mandatory for laying the groundwork for the use of low-frequency systems in future clinical trials. The authors investigate here the in vivo potential thresholds of MRgFUS-induced inertial cavitation and MRgFUS-induced thermal coagulation using MRI, acoustic spectroscopy, and histology. METHODS Ten female piglets that had undergone a craniectomy were sonicated using a 220-kHz transcranial MRgFUS system over an acoustic energy range of 5600–14,000 J. For each piglet, a long-duration sonication (40-second duration) was performed on the right thalamus, and a short sonication (20-second duration) was performed on the left thalam...