Early Quality Life Impairment in Alzheimer Disease’s Patients in Geriatric Department: About 214 Cases in Pitié Salpêtrière Hospital of Paris (France)

Alzheimer’s disease (AD) is the most common neurodegenerative disease causing an alteration of life quality in the terminal stage. The purpose was to report 14 years of experience about the early impact on the quality of life of patients with AD. Methodology: Descriptive retrospective study over 14 years in the geriatric department of Pitié Salpêtrière Hospital, using the activity of daily living, Instrumental activity of daily living, neuropsychological inventory and Hoen Yahr scale evaluated at the time of diagnosis of AD according to the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer Disease’s and Related Disorders Association diagnostic criteria. Results: A total of 214 exploitable files had been listed. At the moment of diagnosis, the mean age was 82.1 years with extremes 68 to 95 with sex ratio 1.6 in women’s favor. The mean socio-cultural level was 4.9 with extremes about 0 to 7. There was poly pathology with a mean Cumulative Illness Rate Scale = 4.6 with extremes 0 to 16. the mean cognitive status was moderate = 22.5 with extremes 0 to 30. Quality life showed moderate impairment of IADL = 9.2 with extreme 3 to 11 compared to activity of daily living. The activity of daily living was more affected in 68 - 80-year-olds, while poly pathology impacted more on IADL in men. The cognitive impairment was more deficient in IADL when the MMSE test was low. The common disorders at the NPI were psychological, behavioral and psychotic. Conclusion: At the early diagnosis of Alzheimer’s Disease cognitive deficiencies were predominant and influenced on global Instrumental activity and psychological, behavioral disorders.

Deterministic and probabilistic analysis of great-depth braced excavations:A 32 m excavation case study in Paris

The Fort d’Issy-Vanves-Clamart(FIVC)braced excavation in France is analyzed to provide insights into the geotechnical serviceability assessment of excavations at great depth within deterministic and probabilistic frameworks.The FIVC excavation is excavated at 32 m below the ground surface in Parisian sedimentary basin and a plane-strain finite element analysis is implemented to examine the wall deflections and ground surface settlements.A stochastic finite element method based on the polynomial chaos Kriging metamodel(MSFEM)is then proposed for the probabilistic analyses.Comparisons with field measurements and former studies are carried out.Several academic cases are then conducted to investigate the great-depth excavation stability regarding the maximum horizontal wall deflection and maximum ground surface settlement.The results indicate that the proposed MSFEM is effective for probabilistic analyses and can provide useful insights for the excavation design and construction.A sensitivity analysis for seven considered random parameters is then implemented.The soil friction angle at the excavation bottom layer is the most significant one for design.The soil-wall interaction effects on the excavation stability are also given.

Peclers Paris 2016/2017秋冬色彩预测

Peclers Paris是法国老牌趋势预测机构,近期他们发布了2016/2017秋冬的国际流行趋势报告,在色彩部分,Peclers Paris特别指出亚洲市场对色彩的影响。大量的中性色将会出现在本季,且丰富多彩,表达了一种对寻常色彩样式加以提升精炼的需求,特别是在亚洲市场上大放异彩的颜色组合。同时,材质的纹理效果在为色彩注入活力和个性方面,仍然作用非凡。

Early Life Quality on Instrumental, Daily and Neuropsychological Activities of Lewy Body Disease about 70 Patients in the Geriatric Department at the PitiéSalpêtrière Hospital of Paris, France

Background: Lewy body disease (LBD) is a neurodegenerative affection responsible for impaired quality of life. The objective was to share the data experience of 14 years concerning the functional, neuropsychological and behaviors effects on geriatrics patients. Methodology: Descriptive retrospective study over 14 years (2005 to 2019) in the geriatrics department of Pitié Salpétrière Hospital, using the instrumentals activity of daily living (IADL) sheets and the neuropsychological inventory (NPI) assessed at the moment diagnosis according to the diagnostic criteria of 2017 and 1996. Results: A total of 70 patients including 55 exploitable files had been listed with a mean age 82.6 years [70 - 91], a sex ratio 1.2 in men favor, a mean socio-cultural level 5.2 [1 - 7], a mean Cumulating Illness Scale (CIRS52) = 10 [1 - 22]. The mean IADL and NPI were respectively 9.3 [3 - 11] and 25.1 [0 - 79]. We found an early global impairment of IADL activities frequent in transport (65%), medication management (49%), and displacement (42%) for basic activities without significant statistical difference between the age and sex groups but statistically significant early involvement with polypathology after adjustment for displacement (45%) and transport (65%). The IADL impairment is significant as soon as the MMS-BREF decreases. Hoen Yahr (HY) scale increase could influences shopping (22%), displacement (27%) after adjustment. NPI disorders frequently found were apathy-depression (31.8% - 25%), anxiety (28%), irritability (25.6%) and sleep disturbance (22.9%) after 80 years old independently of gender and poly-pathology. Also, the best mental status was associated of less disturbance of NPI items. Conclusion: Polypathology, motor disorders and cognitive decline seem to influence IADL while with advanced age, cognitive decline appears to be worsened early in LBD.

Comparison of fatty liver index with noninvasive methods for steatosis detection and quantification

AIM:To compare noninvasive methods presently used for steatosis detection and quantification in nonalcoholic fatty liver disease(NAFLD).METHODS:Cross-sectional study of subjects from the general population,a subgroup from the First Israeli National Health Survey,without excessive alcohol consumption or viral hepatitis.All subjects underwent anthropometric measurements and fasting blood tests.Evaluation of liver fat was performed using four noninvasive methods:the SteatoTest;the fatty liver index(FLI);regular abdominal ultrasound(AUS);and the hepatorenal ultrasound index(HRI).Two of the noninvasive methods have been validated vs liver biopsy and were considered as the reference methods:the HRI,the ratio between the median brightness level of the liver and right kidney cortex;and the SteatoTest,a biochemical surrogate marker of liver steatosis.The FLI is calculated by an algorithm based on triglycerides,body mass index,γ-glutamyl-transpeptidase and waist circumference,that has been validated only vs AUS.FLI < 30 rules out and FLI ≥ 60 rules in fatty liver.RESULTS:Three hundred and thirty-eight volunteers met the inclusion and exclusion criteria and had valid tests.The prevalence rate of NAFLD was 31.1% according to AUS.The FLI was very strongly correlated with SteatoTest(r = 0.91,P < 0.001) and to a lesser but significant degree with HRI(r = 0.55,P < 0.001).HRI and SteatoTest were significantly correlated(r = 0.52,P < 0.001).The κ between diagnosis of fatty liver by SteatoTest(≥ S2) and by FLI(≥ 60) was 0.74,which represented good agreement.The sensitivity of FLI vs SteatoTest was 85.5%,specificity 92.6%,positive predictive value(PPV) 74.7%,and negative predictive value(NPV) 96.1%.Most subjects(84.2%) with FLI < 60 had S0 and none had S3-S4.The κ between diagnosis of fatty liver by HRI(≥ 1.5) and by FLI(≥ 60) was 0.43,which represented only moderate agreement.The sensitivity of FLI vs HRI was 56.3%,specificity 86.5%,PPV 57.0%,and NPV 86.1%.The diagnostic accuracy of FLI for steatosis > 5%,as predicted by SteatoTest,yielded an area under the receiver operating characteristic curve(AUROC) of 0.97(95% CI:0.95-0.98).The diagnostic accuracy of FLI for steatosis> 5%,as predicted by HRI,yielded an AUROC of 0.82(95% CI:0.77-0.87).The κ between diagnosis of fatty liver by AUS and by FLI(≥ 60) was 0.48 for the entire sample.However,after exclusion of all subjects with an intermediate FLI score of 30-60,the κ between diagnosis of fatty liver by AUS and by FLI either ≥ 60 or < 30 was 0.65,representing good agreement.Excluding all the subjects with an intermediate FLI score,the sensitivity of FLI was 80.3% and the specificity 87.3%.Only 8.5% of those with FLI < 30 had fatty liver on AUS,but 27.8% of those with FLI ≥ 60 had normal liver on AUS.CONCLUSION:FLI has striking agreement with SteatoTest and moderate agreements with AUS or HRI.However,if intermediate values are excluded FLI has high diagnostic value vs AUS.

A Mathematical Comparison of the Schwarzschild and Kerr Metrics

A few physicists have recently constructed the generating compatibility conditions (CC) of the Killing operator for the Minkowski (M), Schwarzschild (S) and Kerr (K) metrics. They discovered second order CC, well known for M, but also third order CC for S and K. In a recent paper (DOI:10.4236/jmp.2018.910125) we have studied the cases of M and S, without using specific technical tools such as Teukolski scalars or Killing-Yano tensors. However, even if S(m) and K(m, a) are depending on constant parameters in such a way that S → M when m → 0 and K→ S when a → 0, the CC of S do not provide the CC of M when m → 0 while the CC of K do not provide the CC of S when a → 0. In this paper, using tricky motivating examples of operators with constant or variable parameters, we explain why the CC are depending on the choice of the parameters. In particular, the only purely intrinsic objects that can be defined, namely the extension modules, may change drastically. As the algebroid bracket is compatible with the prolongation/projection (PP) procedure, we provide for the first time all the CC for K in an intrinsic way, showing that they only depend on the underlying Killing algebra and that the role played by the Spencer operator is crucial. We get K < S < M with 2 < 4 < 10 for the Killing algebras and explain why the formal search of the CC for M, S or K are strikingly different, even if each Spencer sequence is isomorphic to the tensor product of the Poincaré sequence for the exterior derivative by the corresponding Lie algebra.

Validation of Sea Level Data in the East Asian Marginal Seas: Comparison between TOPEX/POSEIDON Altimeter and In-Situ Tide Gauges

In an effort to assess the reliability of satellite altimeter systems, the authors conduct a comparative analysis of sea level data that were collected from the TOPEX/POSEIDON (T/P) altimeter and 10 tide gauges (TG) near the satellite passing ground tracks. The analysis is made using datasets collected from marginal sea regions surrounding the Korean Peninsula at T/P cycles of 2 to 230, which correspond to October 1992 to December 1998. Proper treatment of tidal errors is a very critical step in data processing because the study area has very strong tide. When the T/P data are processed, the procedures of Park and Gamberoni (1995) are adapted to reduce errors associated with the tide. When the T/P data are processed in this way, the alias periods of M2, S2, and K1 constituents are found to be 62.1, 58.7, and 173 days repectively. The compatibility of the T/P and TG datasets are examined at various filtering periods. The results indicate that the low-frequency signals of the T/P data can be interpreted more safely with longer filtering periods (such as up to the maximum selected value of 200 days). When RMS errors for the 200-day low-pass filter period are compared with all 10 tidal stations, the values span the range of 2.8 to 6.7 cm. The results of a correlation analysis for this filtering period also show a strong agreement between the T/P and TG datasets across all stations investigated (e.g.,p- values consistently less than 0.001). Hence according to the analysis, the conclusion is made that the analysis of surface sea level using satellite altimeter data can be made safely with reasonably extended filtering periods such as 200 days.

<i>Bordetella holmesii</i>: Comparison of Two Isolates from Blood and a Respiratory Sample

Interest in Bordetella holmesii is increasing, but very little is known about this bacterium, which can be isolated from both blood and respiratory samples. In this study, we compared a B. holmesii isolate from the blood sample of an adult with bacteremia with another isolate from a nasopharyngeal swab from an adult with whooping cough syndrome. Genetic analysis was carried out, targeting relevant genes, and virulence properties were studied in cellular and animal models. Our genomic analysis provided no evidence of traits specific to either blood or respiratory isolates of B. holmesii. Neither isolate was cytotoxic to human tracheal epithelial cells. Both isolates were only weakly invasive and they did not persist within epithelial cells for less than 48 h.

E-Cigarette: A New Tobacco Product for Schoolchildren in Paris

Objectives: To explore if the dramatic decrease in price of e-cigarette has transformed this new product into a product used for tobacco initiation among a teenage population. Methods: The authors added a question in 2012 on e-cigarette in the yearly survey on tobacco consumption in Paris schoolchildren. The study is conducted on a randomly selected sample from 2% of classes since 1991. Results: 277 (8.1%) of the 3409 schoolchildren studied (including 575 non responders to this question) reported having had an experience with e-cigarette. Experimentation rate is 6.4% among the 12 - 14-year-old, 11.8% among the 15 - 16-year-old and 9% among the 17-year-old schoolchildren. Among the 12 - 14- year-old schoolchildren, 64.4% of e-cigarette experimentation was by non-smokers. Of the 17-year-old teenagers who had used e-cigarettes, 12.4% were non-smokers. For the whole population, 33.2% of those having tried e-cigarette are non-smoker, 22.7% occasional smoker, 3.6% ex-smoker and 40.4% daily smoker. Those who experiment cannabis, shisha or binge-drinking are more frequently users of e-cigarette. In the smoker group, there is an inverse trend of rela- tionship between the readiness to quit tobacco and the rate of use of e-cigarette. Conclusion: For teenager’s, e-cigare- ttes have become not a product to aid quit tobacco but a product for experimentation and initiation of cigarette use. Regulation is urgently needed to control the emergent use of this new tobacco product by children.

Parametric Methods for the Regional Assessment of Cardiac Wall Motion Abnormalities: Comparison Study

Left ventricular(LV)dysfunction is mainly assessed by global contractile indices such as ejection fraction and LV Volumes in cardiac MRI.While these indices give information about the presence or not of LV alteration,they are not able to identify the location and the size of such alteration.The aim of this study is to compare the performance of three parametric imaging techniques used in cardiac MRI for the regional quantification of cardiac dysfunction.The proposed approaches were evaluated on 20 patients with myocardial infarction and 20 subjects with normal function.Three parametric images approaches:covariance analysis,parametric images based on Hilbert transform and those based on the monogenic signal were evaluated using cine-MRI frames acquired in three planes of views.The results show that parametric images generated from the monogenic signal were superior in term of sensitivity(89.69%),specificity(86.51%)and accuracy(89.06%)to those based on covariance analysis and Hilbert transform in the detection of contractile dysfunction related to myocardial infarction.Therefore,the parametric image based on the monogenic signal is likely to provide additional regional indices about LV dysfunction and it may be used in clinical practice as a tool for the analysis of the myocardial alterations.

The 26th International Geological Congress, Paris, 1980

In 1878, France hosted the first International Geological Congress on the occasion of the International Exhibition held in Paris that year. The decision to hold such a meeting in France had been taken two years earlier at the Exhibition in Philadelphia. France also wished to host the centenary Congress （102 years in fact, because of the pattern of meetings established after the Second World War）, as this corresponded with the 150th year of the foundation of the Geological Society of France in 1830, on the initiative of Ami Boué and Constant Prévost, who were elected President and Secretary. Happily, this wish was fulfilled （see Figure 1）.

Comparison between open and laparoscopic reversal of Hartmann’s procedure for diverticulitis

AIM: To compare the open and laparoscopic Hartmann’s reversal in patients first treated for complicated diverticulitis.METHODS: Forty-six consecutive patients with diverticular disease were included in this retrospective,singlecenter study of a prospectively maintained colorectal surgery database.All patients underwent conventional Hartmann’s procedures for acute complicated diverticulitis.Other indications for Hartmann’s procedures were excluded.Patients underwent open(OHR) or laparoscopic Hartmann’s reversal(LHR) between 2000 and 2010,and received the same pre-and post-operative protocols of cares.Operative variables,length of stay,short-(at 1 mo) and long-term(at 1 and 3 years) postoperative complications,and surgery-related costs were compared between groups.RESULTS: The OHR group consisted of 18 patients(13 males,mean age ± SD,61.4 ± 12.8 years),and the LHR group comprised 28 patients(16 males,mean age 54.9 ± 14.4 years).The mean operative time and the estimated blood loss were higher in the OHR group(235.8 ± 43.6 min vs 171.1 ± 27.4 min;and 301.1 ± 54.6 mL vs 225 ± 38.6 mL respectively,P = 0.001).Bowel function returned in an average of 4.3 ± 1.7 d in the OHR group,and 3 ± 1.3 d in the LHR group(P = 0.01).The length of hospital stay was significantly longer in the OHR group(11.2 ± 5.3 d vs 6.7 ± 1.9 d,P 【 0.001).The 1 mo complication rate was 33.3% in the OHR(6 wound infections) and 3.6% in the LHR group(1 hemorrhage)(P = 0.004).At 12 mo,the complication rate remained significantly higher in the OHR group(27.8% vs 10.7%,P = 0.03).The anastomotic leak and mortality rates were nil.At 3 years,no patient required re-intervention for surgical complications.The OHR procedure had significantly higher costs(+56%) compared to the LHR procedure,when combining the surgery-related costs and the length of hospital stay.CONCLUSION: LHR appears to be a safe and feasible procedure that is associated with reduced hospitality stays,complication rates,and costs compared to OHR.

3D Vector Reconstruction of the Muscles of the Ventral Region of the Neck from Anatomical Sections of Korean Visible Human at the Paris Descartes Anatomy Laboratory

Objective: To carry out a 3D vector reconstruction of the muscles of the ventral region of the neck from anatomical sections of the “Korean Visible Human” for educational purposes. Materials and Methods: The anatomical subject was a 33-year-old Korean man who died of leukemia. He was 164 cm tall and weighed 55 kgs. The anatomical sections were made in 2010 after an MRI and a CT scan. A special saw (cryomacrotome) made it possible to make cuts 0.2 mm thick on the frozen body, i.e. 5960 cuts. Sections numbered 1500 to 2000 (or 500 cuts covering the neck) were used for our study. A segmentation by manual contouring of each anatomical element of the anterior neck region was done using Winsurf version 3.5 software on a laptop PC running Windows 7 equipped with an 8 gigabyte RAM. Results: We modeled the sternocleidomastoid muscles, the supra-hyoid muscles, the infra-hyoid muscles and the muscle structures of the anterior neck region, the aero-digestive axis of the anterior neck region and the vasculo-nervous axis of the neck. This model is easily manipulated using the Acrobat 3Dpdf interface. Each item accessible in a menu can be displayed, hidden or made transparent, and 3D labels are available as well as educational menus for learning anatomy. This vector model has been integrated into the Diva3d virtual dissection table, a new educational tool used by universities and medical schools to learn anatomy. This model was also uploaded to the Sketchfab? website and 3D printed using an ENDER? pro 3 printer. Conclusion: This original work constitutes a remarkable educational tool for the anatomical study of the anterior neck region and can also be used as a 3D atlas for simulation purposes for training in therapeutic gestures.

3D Vector Reconstruction of the Typical Cervical Vertebra from Anatomical Sections of Korean Visible Human at the Laboratory of Clinical and Digital Anatomy of Paris Descartes University

Aim: To carry out a 3D vector reconstruction of the typical cervical vertebra from anatomical sections of the “Korean Visible Human” for educational purposes. Material and Methods: The anatomical subject was a 33-year-old Korean man who died of leukemia. He was 164 cm tall and weighed 55 kg. This man donated his body to science. Her body was frozen and cut into several anatomical sections after an MRI and CT scan. These anatomical sections were made using a special saw called a 0.2 mm thick cryomacrotome. Thus 8100 cuts were obtained. Only the sections numbered 940 to 1200 were used for our study. A segmentation by manual contouring of the different parts of the typical cervical vertebra was made using the software Winsurf version 3.5 on a laptop PC running Windows 7 equipped with a Ram of 8 gigas. Results: Our 3D vector model of the typical cervical vertebra is easily manipulated using the Acrobat 3DPDF interface. Each part of the vertebra accessible in a menu can be displayed, hidden or made transparent, and 3D labels are available as well as educational menus for learning anatomy. Conclusion: This original work constitutes a remarkable educational tool for the anatomical study of the typical cervical vertebra and can also be used as a 3D atlas for simulation purposes for training in therapeutic gestures.

3D Vector Reconstruction of the Neck Skeleton from the Anatomical Sections of Korean Visible Human at the Anatomical Laboratory of Paris Descartes

Aim: To perform a vector 3D reconstruction of the neck skeleton from the anatomical sections of the “Korean Visible Human” for educational purposes. Material and Methods: The anatomical subject was a 33-year-old Korean male who died of leukemia. It measured 164 cm and weighed 55 kgs. The anatomical cuts were made in 2010 after an MRI and a CT scan. A special saw (cryomacrotome) made it possible to make cuts on the frozen body of 0.2 mm thick or 5960 slices. Sections numbered 1500 to 2000 (500 neck sections) were used for this study. Manual contouring segmentation of each anatomical element of the anterior neck area was done using Winsurf software version 3.5 on a PC. Results: Our vector 3D neck model includes the following: cervical vertebrae, hyoid bone, sternum manubrium and clavicles. This vector model has been integrated into the virtual dissection table Diva3d, a new educational tool used by universities and medical schools to learn anatomy. This model was also put online on the Sketchfab website and printed in 3D using an ENDER 3 printer. Conclusion: This original work is a remarkable educational tool for the study of the skeleton of the neck and can also serve as a 3D atlas for simulation purposes for training therapeutic gestures.

Probabilistic, Statistical and Algorithmic Aspects of the Similarity of Texts and Application to Gospels Comparison

The fundamental problem of similarity studies, in the frame of data-mining, is to examine and detect similar items in articles, papers, and books with huge sizes. In this paper, we are interested in the probabilistic, and the statistical and the algorithmic aspects in studies of texts. We will be using the approach of k-shinglings, a k-shingling being defined as a sequence of k consecutive characters that are extracted from a text (k ≥ 1). The main stake in this field is to find accurate and quick algorithms to compute the similarity in short times. This will be achieved in using approximation methods. The first approximation method is statistical and, is based on the theorem of Glivenko-Cantelli. The second is the banding technique. And the third concerns a modification of the algorithm proposed by Rajaraman et al. ([1]), denoted here as (RUM). The Jaccard index is the one being used in this paper. We finally illustrate these results of the paper on the four Gospels. The results are very conclusive.

Kagome Project:Physical and Numerical Modeling Comparison for a Post-formed Elastic Gridshell

An elastic gridshell is an efficient constructive typology for crossing large spans with little material.A flat elastic grid is built before buckling the structure into shape,in active and post-formed bending.The design and structural analysis of such a structure requires a stage of form finding that can mainly be done:(1)With a physical model:either by a suspended net method,or an active bending model;(2)With a numerical model performed by dynamic relaxation.All these solutions have various biases and assumptions that make them reflect more or less the reality.These three methods have been applied by Happold and Liddell[1]during the design of the Frei Otto’s Mannheim Gridshell which has allowed us to compare the results,and to highlight the significant differences between digital and physical models.Based on our own algorithm called ELASTICA[2],our study focuses on:(1)Comparing the results of the ELASTICA’s numerical models to load tests on physical models;(2)The identification of the various factors that can influence the results and explain the observed differences,some of which are then studied;(3)Applying the results to build a full-scale interlaced lattice elastic gridshell based on the Japanese Kagome pattern.

Comparison of Interval Constraint Propagation Algorithms for Vehicle Localization

Interval constraint propagation (ICP) algorithms allow to solve problems described as constraint satisfaction problems (CSP). ICP has been successfully applied to vehicle localization in the last few years. Once the localization problem has been stated, a large class of ICP solvers can be used. This paper compares a few ICP algorithms, using the same experimental data, in order to rank their performances in terms of accuracy and computing time.

Tonal Noise Prediction of an Automotive Engine Cooling Fan： Comparison between Analytical Models and Acoustic Analogy Results

Valeo, involved in engine cooling fan system design for many years, is interested in noise prediction tools for axial fans. Thus, this paper describes a two-part study of tonal noise computation. The first part deals with the prediction of tonal noise using analytical models. As for the second part, it describes a hybrid approach for predicting tonal noise where the sources are extracted from an Unsteady Reynolds-Averaged Naviers-Stocks （URANS） simulation and then propagated into the far, free field using the Ffowcs Williams and Hawkings＇ acoustic analogy. The computational domain is meshed with 46 million polyhedral elements and the simulation takes into account the exact geometry of the rotor blades, the stator blades and the shroud. The results from the first part show that analytical models can be used for comparisons between different fan geometries, but are unable to provide accurate noise predictions compared to experimental results. The simulation shows non-periodic blade loading over a whole fan revolution, and different blade loading between the blades. This introduces some bias in the assessment of the acoustic performance of the fan. Overall, the results from the hybrid method are in accordance with the experimental results.

Aerospace Clusters and Competitiveness Poles： A France-Quebec Comparison

Aerospace product development and manufacturing are key components of the air transport system. At national levels in developed countries, the aerospace industry is considered as a highly strategic sector. A solid national aerospace industry is therefore a symbol of strength. Countries are pragmatic： the positive impact of a well-developed transportation network on economic growth is indubitable and civil aircraft production is a key element of this network. Countries may also assert their sovereignty by being recognized players in the defence segment of aerospace. This paper will look at the cases of France and Quebec where local governments have invested significant public funding in poles of competitiveness （in the case of France） and clusters （in the case of Quebec）. While our examination of the France and Quebec aerospace scenes reveals a surprisingly large number of groupings, it does not indicate that all their members, large and small, equally benefit from participating in them. In this thick institutional environment, aerospace clusters and poles of competitiveness may compete against each other and become self-serving rather than representing and promoting their members.