Design examples using µ-synthesis: Space shuttle lateral axis FCS during reentry

This paper studies the application of Structured Singular Values (SSV or µ) for analysis and synthesis of the Space Shuttle lateral axis flight control system (FCS) during reentry. While this is a fairly standard FCS problem in most respects, the aircraft model is highly uncertain due to the poorly known aerodynamic characteristics (e.g. aero coefficients). Comparisons are made of the conventional FCS with alternatives based on H∞ optimal control and µ-synthesis. The problem as formulated is particularly interesting and challenging because the uncertainty is large and highly structured

The fractal heart — embracing mathematics in the cardiology clinic

For clinicians grappling with quantifying the complex spatial and temporal patterns of cardiac structure and function (such as myocardial trabeculae, coronary microvascular anatomy, tissue perfusion, myocyte histology, electrical conduction, heart rate, and blood-pressure variability), fractal analysis is a powerful, but still underused, mathematical tool. In this Perspectives article, we explain some fundamental principles of fractal geometry and place it in a familiar medical setting. We summarize studies in the cardiovascular sciences in which fractal methods have successfully been used to investigate disease mechanisms, and suggest potential future clinical roles in cardiac imaging and time series measurements. We believe that clinical researchers can deploy innovative fractal solutions to common cardiac problems that might ultimately translate into advancements for patient care

The development of the Meaning in Life Index (MILI) and its relationship with personality and religious behaviours and beliefs among UK undergraduate students

The scales available for assessing meaning in life appear to be confounded with several related constructs, including purpose in life, satisfaction with life, and goal-directed behaviour. The Meaning in Life Index (MILI), a new instrument devised as a specific measure of meaning in life, was developed from responses to a pool of 22 items rated by a sample of 501 undergraduate students in Wales. The nine-item scale demonstrated sufficient face validity, internal consistency, and scale reliability to commend the instrument for future use. With respect to personality, the MILI scores were most strongly predicted by neuroticism (negatively), and less strongly by extraversion (positively) and psychoticism (negatively). With respect to several religious behavioural variables, those who attended church at least weekly returned significantly higher MILI scores than those who attended church less frequently. Intrinsic religiosity was the only orientation to be significantly associated with the MILI scale scores, although the magnitude of the association was smaller than anticipated. These results suggest that meaning in life is associated more strongly with individual differences in personality than with specific religious behaviours and attitudes. The implications of these results are discussed in terms of individual's personal values and attitudes that might underlie their experience of a meaning in life

Evolutionary selection of alleles in the melanophilin gene that impacts on prostate organ function and cancer risk.

BACKGROUND AND OBJECTIVES: Several hundred inherited genetic variants or SNPs that alter the risk of cancer have been identified through genome-wide association studies. In populations of European ancestry, these variants are mostly present at relatively high frequencies. To gain insight into evolutionary origins, we screened a series of genes and SNPs linked to breast or prostate cancer for signatures of historical positive selection. METHODOLOGY: We took advantage of the availability of the 1000 genome data and we performed genomic scans for positive selection in five different Caucasian populations as well as one African reference population. We then used prostate organoid cultures to provide a possible functional explanation for the interplay between the action of evolutionary forces and the disease risk association. RESULTS: Variants in only one gene showed genomic signatures of positive, evolutionary selection within Caucasian populations melanophilin (MLPH). Functional depletion of MLPH in prostate organoids, by CRISPR/Cas9 mutation, impacted lineage commitment of progenitor cells promoting luminal versus basal cell differentiation and on resistance to androgen deprivation. CONCLUSIONS AND IMPLICATIONS: The MLPH variants influencing prostate cancer risk may have been historically selected for their adaptive benefit on skin pigmentation but MLPH is highly expressed in the prostate and the derivative, positively selected, alleles decrease the risk of prostate cancer. Our study suggests a potential functional mechanism via which MLPH and its genetic variants could influence risk of prostate cancer, as a serendipitous consequence of prior evolutionary benefits to another tissue. LAY SUMMARY: We screened a limited series of genomic variants associated with breast and prostate cancer risk for signatures of historical positive selection. Variants within the melanophilin (MLPH) gene fell into this category. Depletion of MLPH in prostate organoid cultures, suggested a potential functional mechanism for impacting on cancer risk, as a serendipitous consequence of prior evolutionary benefits to another tissue

Clouds over the summertime Sahara: an evaluation of Met Office retrievals from Meteosat Second Generation using airborne remote sensing

Novel methods of cloud detection are applied to airborne remote sensing observations from the unique Fennec aircraft dataset, to evaluate the Met Office-derived products on cloud properties over the Sahara based on the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) on-board the Meteosat Second Generation (MSG) satellite. Two cloud mask configurations are considered, as well as the retrievals of cloud-top height (CTH), and these products are compared to airborne cloud remote sensing products acquired during the Fennec campaign in June 2011 and June 2012. Most detected clouds (67 % of the total) have a horizontal extent that is smaller than a SEVIRI pixel (3 km  ×  3 km). We show that, when partially cloud-contaminated pixels are included, a match between the SEVIRI and aircraft datasets is found in 80 ± 8 % of the pixels. Moreover, under clear skies the datasets are shown to agree for more than 90 % of the pixels. The mean cloud field, derived from the satellite cloud mask acquired during the Fennec flights, shows that areas of high surface albedo and orography are preferred sites for Saharan cloud cover, consistent with published theories. Cloud-top height retrievals however show large discrepancies over the region, which are ascribed to limiting factors such as the cloud horizontal extent, the derived effective cloud amount, and the absorption by mineral dust. The results of the CTH analysis presented here may also have further-reaching implications for the techniques employed by other satellite applications facilities across the world

A study of the perceived risks, benefits and barriers to the use of SDD in adult critical care units (the SuDDICU study)

Peer reviewedPublisher PD

The relationship between priestly motivational styles and personal wellbeing in ministry : exploring the connection between religious orientation and purpose in life among Catholic priests serving in Italy

This study examines the association between priestly motivation (accessed via the psychological notion of religious orientation) and personal wellbeing (accessed via the psychological notion of purpose in life) among a sample of 155 Catholic priests serving in Italy. The data confirm a positive association between intrinsic religious orientation and purpose in life, but a negative association between quest religious orientation and purpose in life. These findings are discussed in light of the expectations placed on Catholic priests by the Church and by society

Requirement of JNK1 for endothelial cell injury in atherogenesis

AbstractObjectiveThe c-Jun N-terminal kinase (JNK) family regulates fundamental physiological processes including apoptosis and metabolism. Although JNK2 is known to promote foam cell formation during atherosclerosis, the potential role of JNK1 is uncertain. We examined the potential influence of JNK1 and its negative regulator, MAP kinase phosphatase-1 (MKP-1), on endothelial cell (EC) injury and early lesion formation using hypercholesterolemic LDLR−/− mice.Methods and resultsTo assess the function of JNK1 in early atherogenesis, we measured EC apoptosis and lesion formation in LDLR−/− or LDLR−/−/JNK1−/− mice exposed to a high fat diet for 6 weeks. En face staining using antibodies that recognise active, cleaved caspase-3 (apoptosis) or using Sudan IV (lipid deposition) revealed that genetic deletion of JNK1 reduced EC apoptosis and lesion formation in hypercholesterolemic mice. By contrast, although EC apoptosis was enhanced in LDLR−/−/MKP-1−/− mice compared to LDLR−/− mice, lesion formation was unaltered.ConclusionWe conclude that JNK1 is required for EC apoptosis and lipid deposition during early atherogenesis. Thus pharmacological inhibitors of JNK may reduce atherosclerosis by preventing EC injury as well as by influencing foam cell formation