2,865 research outputs found
Application of group and transformation theory to the solution of ordinary and partial differential equations Final report, 17 Jan. 1967 - 16 Jan. 1968
Application of transformation groups to solution of partial differential equation
Application of group and transformation theory to the solution of ordinary and partial differential equations Final report
Lie transformation group for solution of partial differential equation
Solution of differential equations by application of transformation groups
Report applies transformation groups to the solution of systems of ordinary differential equations and partial differential equations. Lies theorem finds an integrating factor for appropriate invariance group or groups can be found and can be extended to partial differential equations
Model Transformation for a System of Systems Dependability Safety Case
The presentation reviews the dependability and safety effort of NASA's Independent Verification and Validation Facility. Topics include: safety engineering process, applications to non-space environment, Phase I overview, process creation, sample SRM artifact, Phase I end result, Phase II model transformation, fault management, and applying Phase II to individual projects
Genetically induced cell death in bulge stem cells reveals their redundancy for hair and epidermal regeneration.
Adult mammalian epidermis contains multiple stem cell populations in which quiescent and more proliferative stem and progenitor populations coexist. However, the precise interrelation of these populations in homeostasis remains unclear. Here, we blocked the contribution of quiescent keratin 19 (K19)-expressing bulge stem cells to hair follicle formation through genetic ablation of the essential histone methyltransferase Setd8 that is required for the maintenance of adult skin. Deletion of Setd8 eliminated the contribution of bulge cells to hair follicle regeneration through inhibition of cell division and induction of cell death, but the growth and morphology of hair follicles were unaffected. Furthermore, ablation of Setd8 in the hair follicle bulge blocked the contribution of K19-postive stem cells to wounded epidermis, but the wound healing process was unaltered. Our data indicate that quiescent bulge stem cells are dispensable for hair follicle regeneration and epidermal injury in the short term and support the hypothesis that quiescent and cycling stem cell populations are equipotent.This work was funded by Cancer Research UK (CR-UK; C10701/A15181) and the British Skin Foundation (BSF; 5010). Special thanks go to the mouse/transgenic and histology facilities at WT-MRC-Stem Cell Institute.This is the final version. It was first published by Wiley at http://onlinelibrary.wiley.com/doi/10.1002/stem.1910/abstract
Model Transformation for a System of Systems Dependability Safety Case
Software plays an increasingly larger role in all aspects of NASA's science missions. This has been extended to the identification, management and control of faults which affect safety-critical functions and by default, the overall success of the mission. Traditionally, the analysis of fault identification, management and control are hardware based. Due to the increasing complexity of system, there has been a corresponding increase in the complexity in fault management software. The NASA Independent Validation & Verification (IV&V) program is creating processes and procedures to identify, and incorporate safety-critical software requirements along with corresponding software faults so that potential hazards may be mitigated. This Specific to Generic ... A Case for Reuse paper describes the phases of a dependability and safety study which identifies a new, process to create a foundation for reusable assets. These assets support the identification and management of specific software faults and, their transformation from specific to generic software faults. This approach also has applications to other systems outside of the NASA environment. This paper addresses how a mission specific dependability and safety case is being transformed to a generic dependability and safety case which can be reused for any type of space mission with an emphasis on software fault conditions
Good vibrations: Do electrical therapeutic massagers work?
Health, leisure and beauty activities are increasing in popularity, with a particular emphasis on self-help and alternative health practices. One product type that has increased sales with this expansion is the hand-held electric massager. These are products that use vibration as a means of alleviating muscular strains and pains, as well as promoting relaxation. Paradoxically, these products are extremely popular as gifts, but are soon discarded. A multi-disciplinary research team was commissioned by a British manufacturer of electrical consumer products to investigate user attitudes and perceptions of existing massagers, to identify areas of user dissatisfaction. The manufacturer was also concerned about a possible stigma attached to these products because of an association with sex aids. This paper provides an
account of the perceptions of both consumers and therapists regarding the use of these products. Identifying the differences between the perceptions of consumers and therapists should help provide a basis for effective integration
of user needs, manufacturer requirements, designers’ skills and sound therapeutic practice. The results provide insight to support the development of more effective hand-held massagers
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