A mathematical analysis of the evolution of perturbations in a modified Chaplygin gas model

One approach in modern cosmology consists in supposing that dark matter and dark energy are different manifestations of a single `quartessential' fluid. Following such idea, this work presents a study of the evolution of perturbations of density in a flat cosmological model with a modified Chaplygin gas acting as a single component. Our goal is to obtain properties of the model which can be used to distinguish it from another cosmological models which have the same solutions for the general evolution of the scale factor of the universe, without the construction of the power spectrum. Our analytical results, which alone can be used to uniquely characterize the specific model studied in our work, show that the evolution of the density contrast can be seen, at least in one particular case, as composed by a spheroidal wave function. We also present a numerical analysis which clearly indicates as one interesting feature of the model the appearence of peaks in the evolution of the density constrast.Comment: 21 pages, accepted for publication in General Relativity and Gravitatio

Synchronous communication in PLM environments using annotated CAD models

The connection of resources, data, and knowledge through communication technology plays a vital role in current collaborative design methodologies and Product Lifecycle Management (PLM) systems, as these elements act as channels for information and meaning. Despite significant advances in the area of PLM, most communication tools are used as separate services that are disconnected from existing development environments. Consequently, during a communication session, the specific elements being discussed are usually not linked to the context of the discussion, which may result in important information getting lost or becoming difficult to access. In this paper, we present a method to add synchronous communication functionality to a PLM system based on annotated information embedded in the CAD model. This approach provides users a communication channel that is built directly into the CAD interface and is valuable when individuals need to be contacted regarding the annotated aspects of a CAD model. We present the architecture of a new system and its integration with existing PLM systems, and describe the implementation details of an annotation-based video conferencing module for a commercial CAD application.This work was supported by the Spanish Ministry of Economy and Competitiveness and the FEDER Funds, through the ANNOTA project (Ref. TIN2013-46036-C3-1-R).Camba, JD.; Contero, M.; Salvador Herranz, GM.; Plumed, R. (2016). Synchronous communication in PLM environments using annotated CAD models. Journal of Systems Science and Systems Engineering. 25(2):142-158. https://doi.org/10.1007/s11518-016-5305-5S142158252Abrahamson, S., Wallace, D., Senin, N. & Sferro, P. (2000). Integrated design in a service marketplace. Computer-Aided Design, 32(2):97–107.Ahmed, S. (2005). Encouraging reuse of design knowledge: a method to index knowledge. Design Studies, 26:565–592.Alavi, M. & Tiwana, A (2002). Knowledge integration in virtual teams: the potential role of KMS. Journal of the American Society for Information Science and Technology, 53:1029–1037.Ameri, F. & Dutta, D. (2005). Product lifecycle management: closing the knowledge loops. Computer-Aided Design and Applications, 2(5):577–590.Anderson, A.H., Smallwood, L., MacDonald, R., Mullin, J., Fleming, A. & O'Malley, C. (2000). Video data and video links in mediated communication: what do users value? International Journal of Human-Computer Studies, 52(1):165–187.Arias, E., Eden, H., Fischer, G., Gorman, A. & Scharff, E. (2000). Transcending the individual human mind–creating shared understanding through collaborative design. ACM Transactions on Computer-Human Interaction (TOCHI) 7(1): 84–113.Barley, W.C., Leonardi, P.M., & Bailey, D.E. (2012). Engineering objects for collaboration: strategies of ambiguity and clarity at knowledge boundaries. Human Communication Research, 38:280–308.Boujut, J.F. & Dugdale, J. (2006). Design of a 3D annotation tool for supporting evaluation activities in engineering design. Cooperative Systems Design, COOP 6:1–8.Camba, J., Contero, M., Johnson, M. & Company, P. (2014). Extended 3D annotations as a new mechanism to explicitly communicate geometric design intent and increase CAD model reusability. Computer-Aided Design, 57:61–73.Camba, J., Contero, M. & Salvador-Herranz, G. (2014). Speak with the annotator: promoting interaction in a knowledge-based CAD environment built on the extended annotation concept. Proceedings of the 2014 IEEE 18th International Conference on Computer Supported Cooperative Work in Design (CSCWD), 196–201.Chudoba, K.M., Wynn, E., Lu, M. & Watson-Manheim, M.B. (2005). How virtual are we? Measuring virtuality and understanding its impact in a global organization. Information Systems Journal, 15(4):279–306.Danesi, F., Gardan, N. & Gardan, Y. (2006). Collaborative Design: from Concept to Application. Geometric Modeling and Imaging—New Trends, 90–96.Durstewitz, M., Kiefner, B., Kueke, R., Putkonen, H., Repo, P. & Tuikka, T. (2002). Virtual collaboration environment for aircraft design. Proceedings of the IEEE 6th International Conference on Information Visualisation, 502–507.Fisher, D., Brush, A.J., Gleave, E. & Smith, M.A. (2006). Revisiting Whittaker and Sidner’s email overload ten years later. Proceedings of the 2006 20th Anniversary Conference on Computer Supported Cooperative Work. ACM, BanffFonseca, M.J., Henriques, E., Silva, N., Cardoso, T. & Jorge, J.A. (2006). A collaborative CAD conference tool to support mobile engineering. Rapid Product Development (RPD’06), Marinha Grande, Portugal.Frechette, S.P. (2011). Model based enterprise for manufacturing. Proceedings of the 44th CIRP International Conference on Manufacturing Systems.Fu, W.X., Bian, J. & Xu, Y.M. (2013). A video conferencing system for collaborative engineering design. Applied Mechanics and Materials, 344:246–252.Fuh, J.Y.H. & Li, W.D. (2005). Advances in collaborative CAD: the-state-of-the art. Computer-Aided Design, 37:571–581.Fussell, S.R., Kraut, R.E. & Siegel, J. (2000). Coordination of communication: effects of shared visual context on collaborative work. Proceedings of the 2000 ACM Conference on Computer Supported Cooperative Work, 21–30.Gajewska, H., Kistler, J., Manasse, M.S. & Redell, D. (1994). Argo: a system for distributed collaboration. Proceedings of the ACM Second International Conference on Multimedia, San Francisco, CA, USA. 433–440.Gantz, J., Reinsel, D., Chute, C., Schlichting, W., Mcarthur, J., Minton, S., Xheneti, I., Toncheva, A. & Manfrediz, A. (2007). The expanding digital universe: a forecast of worldwide information growth through 2010. IDC, Massachusetts.Gowan, Jr. J.A. & Downs, J.M. (1994). Video conferencing human-machine interface: a field study. Information and Management, 27(6):341–356.Gupta, A., Mattarelli, E., Seshasai, S. & Broschak, J. (2009). Use of collaborative technologies and knowledge sharing in co-located and distributed teams: towards the 24-h knowledge factory. The Journal of Strategic Information Systems, 18:147–161.Hickson, I. (2009). The Web Socket Protocol IETF, Standards Track.Hong, J., Toye, G. & Leifer, L.J. (1996). Engineering design notebook for sharing and reuse. Computers in Industry, 29:27–35.Isaacs, E.A. & Tang, J.C. (1994). What video can and cannot do for collaboration: a case study. Multimedia Systems, 2(2):63–73.Karsenty, L. (1999). Cooperative work and shared visual context: an empirical study of comprehension problems in side-by-side and remote help dialogues. Human Computer Interaction, 14(3): 283–315.Lahti, H., Seitamaa-Hakkarainen, P. & Hakkarainen, K. (2004). Collaboration patterns in computer supported collaborative designing. Design Studies, 25:351–371.Leenders, R.T.A., Van Engelen, J.M. & Kratzer, J. (2003). Virtuality, communication, and new product team creativity: a social network perspective. Journal of Engineering and Technology Management, 20(1):69–92.Levitt, R.E., Jin, Y. & Dym, C.L. (1991). Knowledge-based support for management of concurrent, multidisciplinary design. Artificial Intelligence for Engineering, Design, Analysis and Manufacturing, 5(2):77–95.Li, C., McMahon, C. & Newnes, L. (2009). Annotation in product lifecycle management: a review of approaches. Proceedings of the ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, DETC2009. Vol. 2. New York: ASME, 797–806.Li, W.D., Lu, W.F., Fuh, J.Y. & Wong, Y.S. (2005). Collaborative computer-aided design-research and development status. Computer-Aided Design, 37(9):931–940.Londono, F., Cleetus, K.J., Nichols, D.M., Iyer, S., Karandikar, H.M., Reddy, S.M., Potnis, S.M., Massey, B., Reddy, A. & Ganti, V. (1992). Coordinating a virtual team. CERC-TR-RN-92-005, Concurrent Engineering Research Centre, West Virginia University, West Virginia.Lubell, J., Chen, K., Horst, J., Frechette, S., & Huang, P. (2012). Model based enterprise/technical data package summit report. NIST Technical Note, 1753.May, A. & Carter, C. (2001). A case study of virtual team working in the European automotive industry. International Journal of Industrial Ergonomics, 27(3):171–186.Olson, J.S., Olson, G.M. & Meader, D.K. (1995). What mix of video and audio is useful for small groups doing remote real-time design work? Proceedings of the SIGCHI Conference on Human Factors in Computing Systems. ACM Press, Addison-Wesley Publishing Co.Ping-Hung, H., Mishra, C.S. & Gobeli, D.H. (2003). The return on R&D versus capital expenditures in pharmaceutical and chemical industries. IEEE Transactions on Engineering Management, 50:141–150.Sharma, A. (2005). Collaborative product innovation: integrating elements of CPI via PLM framework. Computer-Aided Design, 37(13):1425–1434.Shum, S.J.B., Selvin, A.M., Sierhuis, M., Conklin, J., Haley, C.B. & Nuseibeh, B. (2006). Hypermedia support for argumentation-based rationale: 15 Years on from Gibis and Qoc. Rationale Management in Software Engineering, 111–132.Siltanen, P. & Valli, S. (2013). Web-based 3D Mediated Communication in Manufacturing Industry. Concurrent Engineering Approaches for Sustainable Product Development in a Multidisciplinary Environment, 1181–1192. Springer London.Stark, J. (2011). Product Lifecycle Management. 1–16. Springer London.Tavcar, J., Potocnik, U. & Duhovnik, J. (2013). PLM used as a backbone for concurrent engineering in supply chain. Concurrent Engineering Approaches for Sustainable Product Development in a Multi-Disciplinary Environment, 681–692.Tay, F.E.H. & Ming, C. (2001). A shared multi-media design environment for concurrent engineering over the internet. Concurrent Engineering, 9(1):55–63.Tay, F.E.H. & Roy, A. (2003). CyberCAD: a collaborative approach in 3D-CAD technology in a multimedia-supported environment. Computers in Industry, 52(2):127–145.Toussaint, J. & Cheng, K. (2002). Design agility and manufacturing responsiveness on the web. Integrated Manufacturing Systems, 13(5):328–339.Tsoi, K.N. & Rahman, S.M. (1996). Media-on-demand multimedia electronic mail: a tool for collaboration on the web. Proceedings of the 5th IEEE International Symposium on High Performance Distributed Computing.Upton, D.M. & Mcafee, A. (1999). The Real Virtual Factory. Harvard Business School Press, 69–89.Vila, C., Estruch, A., Siller, H.R., Abellán, J.V. & Romero, F. (2007). Workflow methodology for collaborative design and manufacturing. Cooperative Design, Visualization, and Engineering 42–49, Springer Berlin Heidelberg.Wasiak, J., Hicks, B., Newnes, L., Dong, A., & Burrow, L. (2010). Understanding engineering email: the development of a taxonomy for identifying and classifying engineering work. Research in Engineering Design, 21(1):43–64.Wasko, M.M. & Faraj, S. (2005). Why should I share? Examining social capital and knowledge contribution in electronic networks of practice. MIS Quarterly: Management Information Systems, 29:35–57.Yang, Q.Z., Zhang, Y., Miao, C.Y. & Shen, Z.Q. (2008). Semantic annotation of digital engineering resources for multidisciplinary design collaboration. ASME 2008 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, 617–624. American Society of Mechanical Engineers.You, C.F. & Chao, S.N. (2006). Multilayer architecture in collaborative environment. Concurrent Engineering Research and Applications, 14(4):273–281.Yuan, Y.C., Fulk, J., Monge, P.R. & Contractor, N. (2010). Expertise directory development, shared task interdependence, and strength of communication network ties as multilevel predictors of expertise exchange in transactive memory work groups. Communication Research, 37: 20–47

Sequential Broadening of CTL Responses in Early HIV-1 Infection Is Associated with Viral Escape

BACKGROUND: Antigen-specific CTL responses are thought to play a central role in containment of HIV-1 infection, but no consistent correlation has been found between the magnitude and/or breadth of response and viral load changes during disease progression. METHODS AND FINDINGS: We undertook a detailed investigation of longitudinal CTL responses and HIV-1 evolution beginning with primary infection in 11 untreated HLA-A2 positive individuals. A subset of patients developed broad responses, which selected for consensus B epitope variants in Gag, Pol, and Nef, suggesting CTL-induced adaptation of HIV-1 at the population level. The patients who developed viral escape mutations and broad autologous CTL responses over time had a significantly higher increase in viral load during the first year of infection compared to those who did not develop viral escape mutations. CONCLUSIONS: A continuous dynamic development of CTL responses was associated with viral escape from temporarily effective immune responses. Our results suggest that broad CTL responses often represent footprints left by viral CTL escape rather than effective immune control, and help explain earlier findings that fail to show an association between breadth of CTL responses and viral load. Our results also demonstrate that CTL pressures help to maintain certain elements of consensus viral sequence, which likely represent viral escape from common HLA-restricted CTL responses. The ability of HIV to evolve to escape CTL responses restricted by a common HLA type highlights the challenges posed to development of an effective CTL-based vaccine

Mutations in RSPH1 cause primary ciliary dyskinesia with a unique clinical and ciliary phenotype

Rationale: Primary ciliary dyskinesia (PCD) is a genetically heterogeneous recessive disorder of motile cilia, but the genetic cause is not defined for all patients with PCD. Objectives: To identify disease-causingmutations in novel genes, we performed exome sequencing, follow-up characterization, mutation scanning, and genotype-phenotype studies in patients with PCD. Methods: Whole-exome sequencing was performed using NimbleGen capture and Illumina HiSeq sequencing. Sanger-based sequencing was used for mutation scanning, validation, and segregation analysis. Measurements and Main Results: We performed exome sequencing on an affected sib-pair with normal ultrastructure in more than 85% of cilia. A homozygous splice-site mutation was detected in RSPH1 in both siblings; parents were carriers. Screening RSPH1 in 413 unrelated probands, including 325 with PCD and 88 with idiopathic bronchiectasis, revealed biallelic loss-of-function mutations in nine additional probands. Five affected siblings of probands in RSPH1 families harbored the familial mutations. The 16 individuals with RSPH1 mutations had some features of PCD; however, nasal nitric oxide levels were higher than in patients with PCD with other gene mutations (98.3 vs. 20.7 nl/min; P , 0.0003). Additionally, individuals with RSPH1 mutations had a lower prevalence (8 of 16) of neonatal respiratory distress, and later onset of daily wet cough than typical for PCD, and better lung function (FEV1), compared with 75 age- and sex-matched PCD cases (73.0 vs. 61.8, FEV1 % predicted; P = 0.043). Cilia from individuals with RSPH1 mutations had normal beat frequency (6.16Hz at 258C), but an abnormal, circular beat pattern. Conclusions: The milder clinical disease and higher nasal nitric oxide in individuals with biallelic mutations in RSPH1 provides evidence of a unique genotype-phenotype relationship in PCD, and suggests that mutations in RSPH1 may be associated with residual ciliary function

Therapeutic Impact of Cytoreductive Surgery and Irradiation of Posterior Fossa Ependymoma in the Molecular Era: A Retrospective Multicohort Analysis

Posterior fossa ependymoma comprises two distinct molecular variants termed EPN_PFA and EPN_PFB that have a distinct biology and natural history. The therapeutic value of cytoreductive surgery and radiation therapy for posterior fossa ependymoma after accounting for molecular subgroup is not known

Dyslipidemia and the role of adipose tissue in early pregnancy in the BPH/5 mouse model for preeclampsia

The hypertensive pregnancy disorder preeclampsia (PE) is a leading cause of fetal and maternal morbidity/mortality. Obesity increases the risk to develop PE, presumably via the release of inflammatory mediators from the adipose tissue, but the exact etiology remains largely unknown. Using obese PE-like blood pressure high subline 5 (BPH/5) and lean gestational age-matched C57Bl6 mice, we aimed to obtain insight into differential reproductive white adipose tissue (rWAT) gene expression, circulating lipids and inflammation at the maternal-fetal interface during early pregnancy. In addition, we investigated the effect of 7 days 25% calorie restriction (CR) in early pregnancy on gene expression in rWAT and implantation sites. Compared with C57Bl6, female BPH/5 are dyslipidemic before pregnancy and show an amplification of rWAT mass, circulating cholesterol, free fatty acids, and triacylglycerol levels throughout pregnancy. RNA sequencing showed that pregnant BPH/5 mice have elevated gene enrichment in pathways related to inflammation and cholesterol biosynthesis at () . Expression of cholesterol-related , , , and was validated by quantitative reverse-transcription-polymerase chain reaction. CR during the first 7 days of pregnancy restored the relative mRNA expression of these genes to a level comparable to C57Bl6 pregnant females and reduced the expression of circulating leptin and proinflammatory prostaglandin synthase 2 in both rWAT and implantation sites in BPH/5 mice at . Our data suggest a possible role for rWAT in the dyslipidemic state and inflammatory uterine milieu that might underlie the pathogenesis of PE. Future studies should further address the physiological functioning of the adipose tissue in relation to PE-related pregnancy outcomes