Generic approach for deriving reliability and maintenance requirements through consideration of in-context customer objectives

Not all implementations of reliability are equally effective at providing customer and user benefit. Random system failure with no prior warning or failure accommodation will have an immediate, usually adverse impact on operation. Nevertheless, this approach to reliability, implicit in measurements such as ‘failure rate’ and ‘MTBF’, is widely assumed without consideration of potential benefits of pro-active maintenance. Similarly, it is easy to assume that improved maintainability is always a good thing. However, maintainability is only one option available to reduce cost of ownership and reduce the impact of failure. This paper discusses a process for deriving optimised reliability and maintenance requirements through consideration of in-context customer objectives rather than a product in isolation

Hispanic Oral Tradition: Form and Content

The nineteenth-century humanist Johann Gottfried von Herder distinguished "art poetry" from "natural poetry," and he discovered in the latter "the heart and soul of a people" (Bluestein). Scholars aligned with the nationbuilding process all around the v\/orld have frequently turned to the traditions that issue directly from the life of human communities in the effort to capture their true character, to establish their authentic identities. Oral tradition emerges from the fabric of everyday existence; it responds to the immediate and ultimate problems posed by life in human societies. Its insights and artistry derive from individual genius tempered by collective assent. More than any other expressive product, oral literature provides access to the wisdom and resolve of a people acting within and sometimes against the confines of their historical destiny

Influence motor aktivity on physical development of students

The character of organic carbon (OC) in lake waters is strongly dependent on the time water has spent in the landscape as well as in the lake itself due to continuous biogeochemical OC transformation processes. A common view is that upstream lakes might prolong the water retention in the landscape, resulting in an altered OC character downstream. We calculated the number of lakes upstream for 24,742 Swedish lakes in seven river basins spanning from 56º to 68º N. For each of these lakes, we used a lake volume to discharge comparison on a landscape scale to account for upstream water retention by lakes (Tn tot). We found a surprisingly weak relationship between the number of lakes upstream and Tn tot. Accordingly, we found that the coloured fraction of organic carbon was not related to lake landscape position but significantly related to Tn tot when we analysed lake water chemical data from 1,559 lakes in the studied river basins. Thus, we conclude that water renewal along the aquatic continuum by lateral water inputs offsets cumulative retention by lakes. Based on our findings, we suggest integrating Tn tot in studies that address lake landscape position in the boreal zone to better understand variations in the character of organic carbon across lake districts

Direct Toll-like receptor 2 mediated co-stimulation of T cells in the mouse system as a basis for chronic inflammatory joint disease

The pathogenesis of chronic inflammatory joint diseases such as adult and juvenile rheumatoid arthritis and Lyme arthritis is still poorly understood. Central to the various hypotheses in this respect is the notable involvement of T and B cells. Here we develop the premise that the nominal antigen-independent, polyclonal activation of preactivated T cells via Toll-like receptor (TLR)-2 has a pivotal role in the initiation and perpetuation of pathogen-induced chronic inflammatory joint disease. We support this with the following evidence. Both naive and effector T cells express TLR-2. A prototypic lipoprotein, Lip-OspA, from the etiological agent of Lyme disease, namely Borrelia burgdorferi, but not its delipidated form or lipopolysaccharide, was able to provide direct antigen-nonspecific co-stimulatory signals to both antigen-sensitized naive T cells and cytotoxic T lymphocyte (CTL) lines via TLR-2. Lip-OspA induced the proliferation and interferon (IFN)-γ secretion of purified, anti-CD3-sensitized, naive T cells from C57BL/6 mice but not from TLR-2-deficient mice. Induction of proliferation and IFN-γ secretion of CTL lines by Lip-OspA was independent of T cell receptor (TCR) engagement but was considerably enhanced after suboptimal TCR activation and was inhibitable by monoclonal antibodies against TLR-2

A set-based approach for coordination of multi-level collaborative design studies

Presented in this paper is a framework for design coordination of hierarchical (multi-level) design studies. The proposed framework utilizes margin management and set-based design principles for handling the challenges associated with vertical and horizontal design coordination. The former is based on flexible constraints/margins, while the latter is handled by intersecting feasible design spaces across different teams. The framework is demonstrated with an industrial test-case from the UK ATI APPROCONE (Advanced PROduct CONcept analysis Environment) project

Stronger diversity effects with increased environmental stress : a study of multitrophic interactions between oak, powdery mildew and ladybirds

Recent research has suggested that increasing neighbourhood tree species diversity may mitigate the impact of pests or pathogens by supporting the activities of their natural enemies and/or reducing the density of available hosts. In this study, we attempted to assess these mechanisms in a multitrophic study system of young oak (Quercus), oak powdery mildew (PM, caused by Erysiphe spp.) and a mycophagous ladybird (Psyllobora vigintiduo-punctata). We assessed ladybird mycophagy on oak PM in function of different neighbourhood tree species compositions. We also evaluated whether these species interactions were modulated by environmental conditions as suggested by the Stress Gradient Hypothesis. We adopted a complementary approach of a field experiment where we monitored oak saplings subjected to a reduced rainfall gradient in a young planted forest consisting of different tree species mixtures, as well as a lab experiment where we independently evaluated the effect of different watering treatments on PM infections and ladybird mycophagy. In the field experiment, we found effects of neighbourhood tree species richness on ladybird mycophagy becoming more positive as the target trees received less water. This effect was only found as weather conditions grew drier. In the lab experiment, we found a preference of ladybirds to graze on infected leaves from trees that received less water. We discuss potential mechanisms that might explain this preference, such as emissions of volatile leaf chemicals. Our results are in line with the expectations of the Natural Enemies Hypothesis and support the hypothesis that biodiversity effects become stronger with increased environmental stress

Microbial rRNA sequencing analysis of evaporative cooler indoor environments located in the Great Basin Desert region of the United States

Recent studies conducted in the Great Basin Desert region of the United States have shown that skin test reactivity to fungal and dust mite allergens are increased in children with asthma or allergy living in homes with evaporative coolers (EC). The objective of this study was to determine if the increased humidity previously reported in EC homes leads to varying microbial populations compared to homes with air conditioners (AC). Children with physician-diagnosed allergic rhinitis living in EC or AC environments were recruited into the study. Air samples were collected from the child's bedroom for genomic DNA extraction and metagenomic analysis of bacteria and fungi using the Illumina MiSeq sequencing platform. The analysis of bacterial populations revealed no major differences between EC and AC sampling environments. The fungal populations observed in EC homes differed from AC homes. The most prevalent species discovered in AC environments belonged to the genera Cryptococcus (20%) and Aspergillus (20%). In contrast, the most common fungi identified in EC homes belonged to the order Pleosporales and included Alternaria alternata (32%) and Phoma spp. (22%). The variations in fungal populations provide preliminary evidence of the microbial burden children may be exposed to within EC environments in this region