Propulsion Study for Small Transport Aircraft Technology (STAT)

Propulsion requirements were determined for 0.5 and 0.7 Mach aircraft. Sensitivity studies were conducted on both these aircraft to determine parametrically the influence of propulsion characteristics on aircraft size and direct operating cost (DOC). Candidate technology elements and design features were identified and parametric studies conducted to select the STAT advanced engine cycle. Trade off studies were conducted to determine those advanced technologies and design features that would offer a reduction in DOC for operation of the STAT engines. These features were incorporated in the two STAT engines. A benefit assessment was conducted comparing the STAT engines to current technology engines of the same power and to 1985 derivatives of the current technology engines. Research and development programs were recommended as part of an overall technology development plan to ensure that full commercial development of the STAT engines could be initiated in 1988

Obstetric opinions regarding the method of delivery in women that have had surgery for retinal detachment

OBJECTIVES: We sought to determine international obstetric opinions regarding the influence of a history of rhegmatogenous retinal detachment on the management of labour and to review the evidence base. DESIGN: A questionnaire containing closed questions, with pre-coded response opinions, was designed to obtain a cross-section of the obstetric opinions. SETTING: Questionnaires were distributed at the 20th European Congress of Obstetrics and Gynaecology in Lisbon, Portugal. PARTICIPANTS: One hundred questionnaires were distributed among obstetricians attending the congress and 74 agreed to participate. MAIN OUTCOME MEASURES: Participants were asked to state their preferred method of delivery in such patients and the reasons for their recommendation. Furthermore, we questioned whether there was any difference in opinions depending on generation. RESULTS: The majority of respondents (76%) would recommend assisted delivery (either Caesarean section or instrumental delivery), whereas the remaining 24% would advise normal delivery. Generation is not a factor influencing this decision. The majority (58%) based their decision to alter the management of labour on their personal opinion of standard of care. CONCLUSION: The literature shows that there is little evidence to support the belief that previous retinal surgery increases the risk of re-detachment of the retina during spontaneous vaginal delivery. This short survey shows that the majority of an international sample of obstetricians questioned does not share this viewpoint. Therefore, unnecessary interventions may be occurring in otherwise fit women with a history of retinal detachment

Predatory Bacteria: A Potential Ally against Multidrug-Resistant Gram-Negative Pathogens

Multidrug-resistant (MDR) Gram-negative bacteria have emerged as a serious threat to human and animal health. Bdellovibrio spp. and Micavibrio spp. are Gram-negative bacteria that prey on other Gram-negative bacteria. In this study, the ability of Bdellovibrio bacteriovorus and Micavibrio aeruginosavorus to prey on MDR Gram-negative clinical strains was examined. Although the potential use of predatory bacteria to attack MDR pathogens has been suggested, the data supporting these claims is lacking. By conducting predation experiments we have established that predatory bacteria have the capacity to attack clinical strains of a variety of ß-lactamase-producing, MDR Gram-negative bacteria. Our observations indicate that predatory bacteria maintained their ability to prey on MDR bacteria regardless of their antimicrobial resistance, hence, might be used as therapeutic agents where other antimicrobial drugs fail. © 2013 Kadouri et al

A computational exploration of resilience and evolvability of protein–protein interaction networks

Protein-protein interaction (PPI) networks represent complex intra-cellular protein interactions , and the presence or absence of such interactions can lead to biological changes in an organism. Recent network-based approaches have shown that a phenotype's PPI network's resilience to environmental perturbations is related to its placement in the tree of life; though we still do not know how or why certain intra-cellular factors can bring about this resilience. Here, we explore the influence of gene expression and network properties on PPI networks' resilience. We use publicly available data of PPIs for E. coli, S. cerevisiae, and H. sapiens, where we compute changes in network resilience as new nodes (proteins) are added to the networks under three node addition mechanisms-random, degree-based, and gene-expression-based attachments. By calculating the resilience of the resulting networks, we estimate the effectiveness of these node addition mechanisms. We demonstrate that adding nodes with gene-expression-based preferential attachment (as opposed to random or degree-based) preserves and can increase the original resilience of PPI network in all three species, regardless of gene expression distribution or network structure. These findings introduce a general notion of prospective resilience, which highlights the key role of network structures in understanding the evolvability of phenotypic traits