Development of an open source web-based infrastructure for designing medical devices

The term ‘Open Source’ is commonly associated with software due to its proven success, encompassing a user’s ability to review and modify the underlying source code, to disseminate modified or unmodified versions to others, and to use it without facing the prospect of legal repercussions (Siedlok, 2001). In the context of product design, namely medical device design, the concept remains relatively novel with no prior research being reported. A study of applying the open source concept to medical device design by developing a web based infrastructure for its facilitation is reported here. Results: The stakeholder requirements are captured using a semi-structured questionnaire and validated through cross referencing responses to questions with other responses from stakeholders of the same or similar occupation. The most prominent responses are selected as the key stakeholder requirements and utilised in conjunction with the functional system requirements outlined in the System Requirements Specification (SyRS), both sets of requirements provide the foundation for the open source web based infrastructure development. Conclusion: The comprehensiveness of the requirements indicate that the open source web based infrastructure will support the design of all medical devices that are classified as high risk, medium risk or low risk devices, whilst devices external to this scope remain a future certainty

Perspectives on new electrode technology for stimulating peripheral nerves with implantable motor prostheses

Journal ArticleAbstract-The limits of present electrode technology are being reached in current motor prostheses for restoring functional movement in paralyzed people. Improved devices require electrodes and stimulation methods that will activate muscles selectively and independently with less implanted hardware. A practical functional neuromuscular stimulation (FNS) system may need to employ extraneural, intraneural, epimysial, or intramuscular electrodes or a combination of these types. The limitations of current muscle electrodes and the anatomy of peripheral nerve innervation of muscle have pointed to stimulation of peripheral nerve trunks as a promising area for investigation. Attempts to use conventional (extraneural) peripheral nerve electrodes for selective activation of muscles in chronic applications have met with only limited success. Intraneural (intrafascicular) electrodes offer the advantages of greater selectivity and lower power requirements, but these may be offset by the difficulty of inserting delicate electrodes through the collagenous epineurium and perineurium while avoiding unacceptable amounts of trauma. Cuff electrodes require more power than intrafascicular ones but may provide more stable recruitment patterns over time, and the opportunity for retrieval and replacement

Rubber friction in aqueous solutions containing ions

Lubricants ordinarily operate by keeping two sliding surfaces separated. The efficiency of a lubricant may be expressed by equations of hydrodynamics where the mechanical properties of the films of lubricants are adequately defined by the properties of bulk lubricant.In the case of water lubrication of black rubber at slow speeds and low pressures the lubricating ability of water is shown to be enhanced by addition of electrolytes to the water. It is thought that negative ions from the electrolytic solution collect on each sliding surface, repel each other and prevent the close approach of two sliding surfaces. Thus a thicker water film exists between the sliding surfaces than if the ion layers did not exist. The thicker film results in a reduced viscous drag force, lower than can be accounted for by conventional hydrodynamics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22361/1/0000807.pd

Understanding the nature of atmospheric acid processing of mineral dusts in supplying bioavailable phosphorus to the oceans

Acidification of airborne dust particles can dramatically increase the amount of bioavailable phosphorus (P) deposited on the surface ocean. Experiments were conducted to simulate atmospheric processes and determine the dissolution behaviour of phosphorus compounds in dust and dust precursors oils. Acid dissolution occurs rapidly (seconds to minutes) and is controlled by the amount of H + ions present. For H + 10-4 mol per gram of dust, the amount of phosphorus (and Ca) released follows a power law dependent on the amount of H + consumed until all inorganic phosphorus minerals are exhausted and the final pH remains acidic. Once dissolved, phosphorus will stay in solution due to slow precipitation kinetics. Dissolution of apatite-P, the major mineral phase in dust (79-96%), occurs whether CaCO 3 is present or not, though the increase in dissolved phosphorus is greater if CaCO 3 is absent or if the particles are externally mixed. The system was modelled adequately as a simple mixture of apatite-P and calcite. Phosphorus dissolves readily by acid processes in the atmosphere in contrast to iron, which dissolves slower and is subject to re-precipitation at cloud water pH. We show that acidification can increase bioavailable phosphorus deposition over large areas of the globe, and may explain much of the previously observed patterns of variability in leachable phosphorus in oceanic areas where primary productivity is limited by this nutrient (e.g. Mediterranean)

Genetic Variation in DNA Repair Pathways and Risk of Non-Hodgkin's Lymphoma

Molecular and genetic evidence suggests that DNA repair pathways may contribute to lymphoma susceptibility. Several studies have examined the association of DNA repair genes with lymphoma risk, but the findings from these reports have been inconsistent. Here we provide the results of a focused analysis of genetic variation in DNA repair genes and their association with the risk of non-Hodgkin's lymphoma (NHL). With a population of 1,297 NHL cases and 1,946 controls, we have performed a two-stage case/control association analysis of 446 single nucleotide polymorphisms (SNPs) tagging the genetic variation in 81 DNA repair genes. We found the most significant association with NHL risk in the ATM locus for rs227060 (OR = 1.27, 95% CI: 1.13–1.43, p = 6.77×10−5), which remained significant after adjustment for multiple testing. In a subtype-specific analysis, associations were also observed for the ATM locus among both diffuse large B-cell lymphomas (DLBCL) and small lymphocytic lymphomas (SLL), however there was no association observed among follicular lymphomas (FL). In addition, our study provides suggestive evidence of an interaction between SNPs in MRE11A and NBS1 associated with NHL risk (OR = 0.51, 95% CI: 0.34–0.77, p = 0.0002). Finally, an imputation analysis using the 1,000 Genomes Project data combined with a functional prediction analysis revealed the presence of biologically relevant variants that correlate with the observed association signals. While the findings generated here warrant independent validation, the results of our large study suggest that ATM may be a novel locus associated with the risk of multiple subtypes of NHL

Endomorphism algebras of Abelian varieties with special reference to superelliptic Jacobians

This is (mostly) a survey article. We use an information about Galois properties of points of small order on an Abelian variety in order to describe its endomorphism algebra over an algebraic closure of the ground field. We discuss in detail applications to jacobians of cyclic covers of the projective line

Out-of-School Time and Adolescent Substance Use

PURPOSE: High levels of adolescent substance use are linked to lower academic achievement, reduced schooling, and delinquency. We assess four types of out-of-school-time (OST) contexts—unsupervised time with peers, sports, organized activities, and paid employment–in relation to tobacco, alcohol, and marijuana use at the end of high school. Other research has examined these OST contexts in isolation, limiting efforts to disentangle potentially confounded relations. METHODS: Longitudinal data from the NICHD Study of Early Child Care and Youth Development (N=766) examined associations between different OST contexts during high school and substance use at the end of high school. RESULTS: Unsupervised time with peers increased the odds of tobacco, alcohol, and marijuana use whereas sports increased the odds of alcohol use and decreased the odds of marijuana use. Paid employment increased the odds of tobacco and alcohol use. Unsupervised time with peers predicted increased amounts of tobacco, alcohol, and marijuana use, while sports predicted decreased amounts of tobacco and marijuana use and increased amounts of alcohol use at the end of high school. CONCLUSIONS: Although unsupervised time with peers, sports, and paid employment were differentially linked to the odds of substance use, only unsupervised time with peers and sports were significantly associated with the amount of tobacco, alcohol, and marijuana use at the end of high school. These findings underscore the value of considering OST contexts in relation to strategies to promote adolescent health. Reducing unsupervised time with peers and increasing sports participation may have positive impacts on reducing substance use

Genetic Interactions between the Drosophila Tumor Suppressor Gene ept and the stat92E Transcription Factor

Tumor Susceptibility Gene-101 (TSG101) promotes the endocytic degradation of transmembrane proteins and is implicated as a mutational target in cancer, yet the effect of TSG101 loss on cell proliferation in vertebrates is uncertain. By contrast, Drosophila epithelial tissues lacking the TSG101 ortholog erupted (ept) develop as enlarged undifferentiated tumors, indicating that the gene can have anti-growth properties in a simple metazoan. A full understanding of pathways deregulated by loss of Drosophila ept will aid in understanding potential links between mammalian TSG101 and growth control.We have taken a genetic approach to the identification of pathways required for excess growth of Drosophila eye-antennal imaginal discs lacking ept. We find that this phenotype is very sensitive to the genetic dose of stat92E, the transcriptional effector of the Jak-Stat signaling pathway, and that this pathway undergoes strong activation in ept mutant cells. Genetic evidence indicates that stat92E contributes to cell cycle deregulation and excess cell size phenotypes that are observed among ept mutant cells. In addition, autonomous Stat92E hyper-activation is associated with altered tissue architecture in ept tumors and an effect on expression of the apical polarity determinant crumbs.These findings identify ept as a cell-autonomous inhibitor of the Jak-Stat pathway and suggest that excess Jak-Stat signaling makes a significant contribution to proliferative and tissue architectural phenotypes that occur in ept mutant tissues

Role of SPI-1 Secreted Effectors in Acute Bovine Response to Salmonella enterica Serovar Typhimurium: A Systems Biology Analysis Approach

Salmonella enterica Serovar Typhimurium (S. Typhimurium) causes enterocolitis with diarrhea and polymorphonuclear cell (PMN) influx into the intestinal mucosa in humans and calves. The Salmonella Type III Secretion System (T3SS) encoded at Pathogenicity Island I translocates Salmonella effector proteins SipA, SopA, SopB, SopD, and SopE2 into epithelial cells and is required for induction of diarrhea. These effector proteins act together to induce intestinal fluid secretion and transcription of C-X-C chemokines, recruiting PMNs to the infection site. While individual molecular interactions of the effectors with cultured host cells have been characterized, their combined role in intestinal fluid secretion and inflammation is less understood. We hypothesized that comparison of the bovine intestinal mucosal response to wild type Salmonella and a SipA, SopABDE2 effector mutant relative to uninfected bovine ileum would reveal heretofore unidentified diarrhea-associated host cellular pathways. To determine the coordinated effects of these virulence factors, a bovine ligated ileal loop model was used to measure responses to wild type S. Typhimurium (WT) and a ΔsipA, sopABDE2 mutant (MUT) across 12 hours of infection using a bovine microarray. Data were analyzed using standard microarray analysis and a dynamic Bayesian network modeling approach (DBN). Both analytical methods confirmed increased expression of immune response genes to Salmonella infection and novel gene expression. Gene expression changes mapped to 219 molecular interaction pathways and 1620 gene ontology groups. Bayesian network modeling identified effects of infection on several interrelated signaling pathways including MAPK, Phosphatidylinositol, mTOR, Calcium, Toll-like Receptor, CCR3, Wnt, TGF-β, and Regulation of Actin Cytoskeleton and Apoptosis that were used to model of host-pathogen interactions. Comparison of WT and MUT demonstrated significantly different patterns of host response at early time points of infection (15 minutes, 30 minutes and one hour) within phosphatidylinositol, CCR3, Wnt, and TGF-β signaling pathways and the regulation of actin cytoskeleton pathway

Análisis sincrónico de la gobernanza universitaria: una mirada teórica a los años sesenta y setenta

Resumen Estudiar las perspectivas en el campo del gobierno de las universidades tiene cada día mayor preeminencia, especialmente si se toma en cuenta la incuestionable necesidad de avanzar hacía organizaciones más eficientes, conectadas con las expectativas que sobre ellas tiene la sociedad. Considerando este escenario, el trabajo se ha planteado como propósito central realizar un análisis de carácter sincrónico del concepto de gobernanza y la constitución de los gobiernos universitarios. Desde el punto de vista metodológico se utilizaron fuentes secundarias: una revisión de papers publicados esencialmente en revistas de habla inglesa. El estudio comprende las décadas del sesenta y el setenta. Se centra en las raíces del concepto de gobernanza universitaria, en la delineación de los actores que participan en sus gobiernos y en las relaciones de poder que fluyen entre ellos.Entre las principales conclusiones, se pueden destacar como el estamento académico desde el principio de las universidades ha ocupado el rol casi plenipotenciario en su respectivo gobierno, producto de esto, en el correr del desarrollo y mientras la complejidad organizacional se incrementaba, es que fue necesario incorporar nuevos actores a los sistemas de gestión; todo lo anterior, teniendo en cuenta que dos elementos han sido fundamentales para la sobrevivencia de este tipo de instituciones, la legitimidad otorgada por la sociedad y los principios de estrategias del ámbito de la gestión