Development of an advanced pitch active control system for a wide body jet aircraft

An advanced PACS control law was developed for a commercial wide-body transport (Lockheed L-1011) by using modern control theory. Validity of the control law was demonstrated by piloted flight simulation tests on the NASA Langley visual motion simulator. The PACS design objective was to develop a PACS that would provide good flying qualities to negative 10 percent static stability margins that were equivalent to those of the baseline aircraft at a 15 percent static stability margin which is normal for the L-1011. Also, the PACS was to compensate for high-Mach/high-g instabilities that degrade flying qualities during upset recoveries and maneuvers. The piloted flight simulation tests showed that the PACS met the design objectives. The simulation demonstrated good flying qualities to negative 20 percent static stability margins for hold, cruise and high-speed flight conditions. Analysis and wind tunnel tests performed on other Lockheed programs indicate that the PACS could be used on an advanced transport configuration to provide a 4 percent fuel savings which results from reduced trim drag by flying at negative static stability margins

Women's experiences of group antenatal care in Australia-the CenteringPregnancy Pilot Study

Objective: to describe the experiences of women who were participants in the Australian CenteringPregnancy Pilot Study. CenteringPregnancy is an innovative model of care where antenatal care is provided in a group environment. The aim of the pilot study was to determine whether it would be feasible to implement this model of care in Australia. Design: a descriptive study was conducted. Data included clinical information from hospital records, and antenatal and postnatal questionnaires. Setting: two metropolitan hospitals in Sydney, Australia. Participants: 35 women were recruited to the study and 33 ultimately received all their antenatal care (eight sessions) through five[CH1] CenteringPregnancy groups. Findings: difficulties with recruitment within a short study timeline resulted in only 35 (20%) of 171 women who were offered group antenatal care choosing to participate. Most women chose this form of antenatal care in order to build friendships and support networks. Attendance rates were high and women appreciated the opportunity and time to build supportive relationships through sharing knowledge, ideas and experiences with other women and with midwives facilitating the groups. The opportunity for partners to attend was identified as important. Clinical outcomes for women were in keeping with those for women receiving standard care; however, the numbers were small. Conclusion: the high satisfaction of the women suggests that CenteringPregnancy is an appropriate model of care for many women in Australian settings, particularly if recruitment strategies are addressed and women's partners can participate. Implications for practice: CenteringPregnancy group antenatal care assists women with the development of social support networks and is an acceptable way in which to provide antenatal care in an Australian setting. Recruitment strategies should include ensuring that practitioners are confident in explaining the advantages of group antenatal care to women in early pregnancy. Further research needs to be conducted to implement this model of care more widely. © 2009 Elsevier Ltd

Scales for scales: An open look at the open sea

Fisheries are among the most complex and tightly coupled social-ecological systems. This thesis develops new perspectives on the spatial features of fisheries, and on common pool resources in general. The central model of the work is the Distributed Commons, a commons spread across space with local and cross-boundary interactions. The model is founded in evidence from historical analysis and complexity theory, and offers insights for management and broader sustainable development policy. The second part of the thesis uses empirical analysis, applying Bayesian and econometric techniques, to study the spatial features exposed by the model. Finally, a computational model is calibrated for exploring the consequences of this theory through experiments. The implications of the Distributed Commons model are relevant to many areas of sustainable development, including atmospheric pollution, environmental degradation, and the use of ecosystem resources

The missing risks of climate change

The risks of climate change are enormous, threatening the lives and livelihoods of millions to billions. The economic consequences of many of the complex risks associated with climate change cannot, however, currently be quantified. We argue that these unquantified, poorly understood, and often deeply uncertain risks can and should be included in economic evaluations and decision making processes. We present an overview of these unquantified risks and an ontology of them founded on the reasons behind their lack of robust evaluation. These consist of risks missing due to (a) delays in sharing knowledge and expertise across disciplines, (b) spatial and temporal variations of climate impacts, (c) feedbacks and interactions between risks, (d) deep uncertainty in our knowledge, and (e) currently unidentified risks. We highlight collaboration needs within and between the natural and social science communities to address these gaps. We also provide an qpproach for integrating assessments or speculations of these risks in a way which accounts for interdependencies, avoids double counting and makes assumptions clear. Multiple paths exist for engaging with these missing risks, with both model-based quantification and non-model-based qualitative assessments playing crucial roles

Report of CE on Semantic DS

The Semantic DS allows describing the world depicted by the AV content and interpreting that world, i.e., the “about” of the AV content or depicted narrative reality, which sometimes is imaginary. This document reports on the core experiment on the Semantic DS [6]. The CE originally started at the Maui meeting in December 1999 [3]. Progress reports of the CE were provided at the Geneva meeting [1] and at the Beijing meeting [2]. In Beijing, some components of the Semantic DS were promoted to the XM: Semantic DS, Object DS, PersonObject DS, Event DS, State DS, MediaOccurrence DS, SemanticTime DS, SemanticLocation DS, UsageLabel D, and some semantic relations. The main tasks of this core experiment have been the following: 1) To refine the specification of the Semantic DS by solving identified issues; 2) To define the Conceptual DSs; 3) To recommend the standardization of more semantic relations; 4) To investigate the use of membership functions to describe the strength of relations; 5) To generate simple and complex semantic descriptions of multimedia material; 6) To implement a retrieval and browsing application/s that uses the generated descriptions and that shows the functionality of the UsageLabel D, the Conceptual DSs, the State DS, and membership functions for relations, especially; 7) To recommend changes and additions to the Semantic DS based on the results of the experiment. The retrieval application that the CE has accomplished two objectives: (1) to show the utility of the components of the Semantic DS in a retrieval scenario, and (2) to be the software for the MPEG-7 XM platform

High-yield production of a super-soluble miniature spidroin for biomimetic high-performance materials

The mechanical properties of artificial spider silks are approaching a stage where commercial applications become realistic. However, the yields of recombinant silk proteins that can be used to produce fibers with good mechanical properties are typically very low and many purification and spinning protocols still require the use of urea, hexafluoroisopropanol, and/or methanol. Thus, improved production and spinning methods with a minimal environmental impact are needed. We have previously developed a miniature spider silk protein that is characterized by high solubility in aqueous buffers and spinnability in biomimetic set-ups. In this study, we developed a production protocol that resulted in an expression level of >20 g target protein per liter in an Escherichia coli fedbatch culture, and subsequent purification under native conditions yielded 14.5 g/l. This corresponds to a nearly six-fold increase in expression levels, and a 10-fold increase in yield after purification compared to reports for recombinant spider silk proteins. Biomimetic spinning using only aqueous buffers resulted in fibers with a toughness modulus of 74 MJ/m(3), which is the highest reported for biomimetically as-spun artificial silk fibers. Thus, the process described herein represents a milestone for the economic production of biomimetic silk fibers for industrial applications

Behavioral, morphological, and ecological trait evolution in two clades of New World Sparrows (Aimophila and Peucaea, Passerellidae)

Copyright 2020 Cicero et al. The New World sparrows (Passerellidae) are a large, diverse group of songbirds that vary in morphology, behavior, and ecology. Thus, they are excellent for studying trait evolution in a phylogenetic framework. We examined lability versus conservatism in morphological and behavioral traits in two related clades of sparrows (Aimophila, Peucaea), and assessed whether habitat has played an important role in trait evolution. We first inferred a multi-locus phylogeny which we used to reconstruct ancestral states, and then quantified phylogenetic signal among morphological and behavioral traits in these clades and in New World sparrows more broadly. Behavioral traits have a stronger phylogenetic signal than morphological traits. Specifically, vocal duets and song structure are the most highly conserved traits, and nesting behavior appears to be maintained within clades. Furthermore, we found a strong correlation between open habitat and unpatterned plumage, complex song, and ground nesting. However, even within lineages that share the same habitat type, species vary in nesting, plumage pattern, song complexity, and duetting. Our findings highlight trade-offs between behavior, morphology, and ecology in sparrow diversification

Challenges and innovations in the economic evaluation of the risks of climate change

A large discrepancy exists between the dire impacts that most natural scientists project we could face from climate change and the modest estimates of damages calculated by mainstream economists. Economic assessments of climate change risks are intended to be comprehensive, covering the full range of physical impacts and their associated market and non-market costs, considering the greater vulnerability of poor people and the challenges of adaptation. Available estimates still fall significantly short of this goal, but alternative approaches that have been proposed attempt to address these gaps. This review seeks to provide a common basis for natural scientists, social scientists, and modellers to understand the research challenges involved in evaluating the economic risks of climate change. Focusing on the estimation processes embedded in economic integrated assessment models and the concerns raised in the literature, we summarise the frontiers of research relevant to improving quantitative damage estimates, representing the full complexity of the associated systems, and evaluating the impact of the various economic assumptions used to manage this complexity

Impact of physio-chemical spinning conditions on the mechanical properties of biomimetic spider silk fibers

Artificial spider silk has emerged as a biobased fiber that could replace some petroleum-based materials that are on the market today. Recent progress made it possible to produce the recombinant spider silk protein NT2RepCT at levels that would make the commercialization of fibers spun from this protein economically feasible. However, for most applications, the mechanical properties of the artificial silk fibers need to be improved. This could potentially be achieved by redesigning the spidroin, and/or by changing spinning conditions. Here, we show that several spinning parameters have a significant impact on the fibers’ mechanical properties by tensile testing more than 1000 fibers produced under 92 different conditions. The most important factors that contribute to increasing the tensile strength are fast reeling speeds and/or employing post-spin stretching. Stretching in combination with optimized spinning conditions results in fibers with a strength of >250 MPa, which is the highest reported value for fibers spun using natively folded recombinant spidroins that polymerize in response to shear forces and lowered pH