Demonstration of decomposition and optimization in the design of experimental space systems

Effective design strategies for a class of systems which may be termed Experimental Space Systems (ESS) are needed. These systems, which include large space antenna and observatories, space platforms, earth satellites and deep space explorers, have special characteristics which make them particularly difficult to design. It is argued here that these same characteristics encourage the use of advanced computer-aided optimization and planning techniques. The broad goal of this research is to develop optimization strategies for the design of ESS. These strategics would account for the possibly conflicting requirements of mission life, safety, scientific payoffs, initial system cost, launch limitations and maintenance costs. The strategies must also preserve the coupling between disciplines or between subsystems. Here, the specific purpose is to describe a computer-aided planning and scheduling technique. This technique provides the designer with a way to map the flow of data between multidisciplinary analyses. The technique is important because it enables the designer to decompose the system design problem into a number of smaller subproblems. The planning and scheduling technique is demonstrated by its application to a specific preliminary design problem

Moving Beyond Fulfillment: Wisdom Years Stories of Passion, Perseverance, and Productivity

Seven participants were interviewed to uncover how they remain so productive in their wisdom years, those typically marked by retirement. Participants included a leading educational psychologist, a renowned national television news anchor, a four-time national champion collegiate coach, the founder and former chief executive of Arbor Day Foundation, a university scholar turned playwright, and two female adventurers who quit their jobs, sold their possessions, and have lived a nomadic life, hiking thousands of miles throughout America. Their wisdom years stories describe how and why they shun retirement and remain productive. The article concludes with seven advice-laden conclusions for readers: (a) Do not retire, but if you do, retire to something, (b) follow your bliss, (c) work hard, (d) offset aging challenges, (e) be inspired by role models, (f) be a life-long learner, and (g) take heed of the universe conspiring

Simulation study on the measured difference in fuel consumption between real-world driving and ECE-15 of a hybrid electric vehicle

Hybrid electric vehicles (HEVs) are sensitive to the driving conditions under which they are used, leading to greater fuel consumption than quoted by the manufacturer, and therefore higher CO emissions. Real-world driving can be very different from the legislative drive cycles as speeds are greater, there are faster changes in speed, and these changes occur at a greater frequency. This study aims to investigate where the differences between real-world driving and the ECE-15 urban drive cycle occur through development of a real-world drive cycle and via a system simulation study. A second generation 2004 Toyota Prius equipped with a GPS (Global Positioning System) data logging system was used to collect data while in use by Loughborough University Security over a period of 9 months. These data were used for the development of a drive cycle, Loughborough University Urban Drive Cycle (LUUDC), representing urban driving around the university campus and local urban area. The same vehicle was tested on a chassis dynamometer on the LUUDC against the ECE-15 cycle and others. Fuel consumption was measured and CO emissions were calculated and compared. A model based on Autonomie vehicle simulation software was used to simulate and analyse the differences. The test and modelling results showed higher fuel consumption on LUUDC than ECE-15. The reasons for this will be discussed in this paper

Biomechanical evaluation of shape-memory alloy staples for internal fixation—an in vitro study

Background: The field of orthopaedics is a constantly evolving discipline. Despite the historical success of plates, pins and screws in fracture reduction and stabilisation, there is a continuing search for more efficient and improved methods of fracture fixation. The aim of this study was to evaluate shape-memory staples and to compare them to a currently used implant for internal fracture fixation. Multi-plane bending stability and interfragmentary compression were assessed across a simulated osteotomy using single and double-staple fixation and compared to a bridging plate. Methods: Transverse osteotomies were made in polyurethane blocks (20 × 20 × 120 mm) and repairs were performed with one (n = 6), or two (n = 6) 20 mm nitinol staples, or an eight-hole 2.7 mm quarter-tubular plate (n = 6). A pressure film was placed between fragments to determine contact area and compressive forces before and after loading. Loading consisted of multi-planar four-point bending with an actuator displacement of 3 mm. Gapping between segments was recorded to determine loads corresponding to a 2 mm gap and residual post-load gap. Results: Staple fixations showed statistically significant higher mean compressive loads and contact areas across the osteotomy compared to plate fixations. Double-staple constructs were superior to single-staple constructs for both parameters (p < 0.001). Double-staple constructs were significantly stiffer and endured significantly larger loads before 2 mm gap formation compared to other constructs in the dorsoventral plane (p < 0.001). However, both staple constructs were significantly less stiff and tolerated considerably lower loads before 2 mm gap formation when compared to plate constructs in the ventrodorsal and right-to-left lateral loading planes. Loading of staple constructs showed significantly reduced permanent gap formation in all planes except ventrodorsally when compared to plate constructs. Conclusions: Although staple fixations were not as stable as plate fixations in particular loading planes, double-staple constructs demonstrated the most consistent bending stiffness in all planes. Placing two perpendicular staples is suggested instead of single-staples whenever possible, with at least one staple applied on the compression side of the anticipated loading to improve construct stability

Cancer Morbidity in Lamp Manufacturing Workers

A historical prospective study of cancer in lamp manufacturing workers in one plant was conducted. All men and women who worked for a total of at least 6 months and were employed at some time between 1960 and 1975 were included. Work histories were abstracted and subjects were divided according to whether they had worked in the coiling and wire drawing area (CWD). Cancer morbidity from 1964 to 1982 was ascertained via the provincial registry, and was compared with the site-specific incidence in Ontario, adjusting for age, sex and calendar period. Of particular interest were primary breast and gynecological cancers in women. The cancers of a priori concern were significantly increased in women in CWD, but not elsewhere in the plant. The excess was greatest in those with more than 5 yr exposure (in CWD) and more than 15 yr since first working in CWD, with eight cases of breast and gynecological cancers observed in this category compared with 2.67 expected. Only three cancers occurred in men in CWD. Environmental measurements had not been made in the past and little information was available on substances used in the 1940s and 1950s, the period when the women with the highest excess began employment. It is known that methylene chloride and trichlorethylene have been used, but not enough is known about the dates and patterns of use to draw any conclusions about their relationship with the increase in disease

Simulation study on the measured difference in fuel consumption between real-world driving and ECE-15 of a hybrid electric vehicle

Hybrid electric vehicles (HEVs) are sensitive to the driving conditions under which they are used, leading to greater fuel consumption than quoted by the manufacturer, and therefore higher CO emissions. Real-world driving can be very different from the legislative drive cycles as speeds are greater, there are faster changes in speed, and these changes occur at a greater frequency. This study aims to investigate where the differences between real-world driving and the ECE-15 urban drive cycle occur through development of a real-world drive cycle and via a system simulation study. A second generation 2004 Toyota Prius equipped with a GPS (Global Positioning System) data logging system was used to collect data while in use by Loughborough University Security over a period of 9 months. These data were used for the development of a drive cycle, Loughborough University Urban Drive Cycle (LUUDC), representing urban driving around the university campus and local urban area. The same vehicle was tested on a chassis dynamometer on the LUUDC against the ECE-15 cycle and others. Fuel consumption was measured and CO emissions were calculated and compared. A model based on Autonomie vehicle simulation software was used to simulate and analyse the differences. The test and modelling results showed higher fuel consumption on LUUDC than ECE-15. The reasons for this will be discussed in this paper

Multifunctional supramolecular polymer networks as next-generation consolidants for archaeological wood conservation.

The preservation of our cultural heritage is of great importance to future generations. Despite this, significant problems have arisen with the conservation of waterlogged wooden artifacts. Three major issues facing conservators are structural instability on drying, biological degradation, and chemical degradation on account of Fe(3+)-catalyzed production of sulfuric and oxalic acid in the waterlogged timbers. Currently, no conservation treatment exists that effectively addresses all three issues simultaneously. A new conservation treatment is reported here based on a supramolecular polymer network constructed from natural polymers with dynamic cross-linking formed by a combination of both host-guest complexation and a strong siderophore pendant from a polymer backbone. Consequently, the proposed consolidant has the ability to chelate and trap iron while enhancing structural stability. The incorporation of antibacterial moieties through a dynamic covalent linkage into the network provides the material with improved biological resistance. Exploiting an environmentally compatible natural material with completely reversible chemistries is a safer, greener alternative to current strategies and may extend the lifetime of many culturally relevant waterlogged artifacts around the world.This is the author's accepted manuscript. The final version is available from PNAS at http://www.pnas.org/content/111/50/17743.long

Adaptive Introgression across Semipermeable Species Boundaries between Local Helicoverpa zea and Invasive Helicoverpa armigera Moths.

Hybridization between invasive and native species has raised global concern, given the dramatic increase in species range shifts and pest outbreaks due to anthropogenic dispersal. Nevertheless, secondary contact between sister lineages of local and invasive species provides a natural laboratory to understand the factors that determine introgression and the maintenance or loss of species barriers. Here, we characterize the early evolutionary outcomes following secondary contact between invasive Helicoverpa armigera and native H. zea in Brazil. We carried out whole-genome resequencing of Helicoverpa moths from Brazil in two temporal samples: during the outbreak of H. armigera in 2013 and 2017. There is evidence for a burst of hybridization and widespread introgression from local H. zea into invasive H. armigera coinciding with H. armigera expansion in 2013. However, in H. armigera, the admixture proportion and the length of introgressed blocks were significantly reduced between 2013 and 2017, suggesting selection against admixture. In contrast to the genome-wide pattern, there was striking evidence for adaptive introgression of a single region from the invasive H. armigera into local H. zea, including an insecticide resistance allele that increased in frequency over time. In summary, despite extensive gene flow after secondary contact, the species boundaries are largely maintained except for the single introgressed region containing the insecticide-resistant locus. We document the worst-case scenario for an invasive species, in which there are now two pest species instead of one, and the native species has acquired resistance to pyrethroid insecticides through introgression

Endoscopic ultrasonography-identified celiac adenopathy remains a poor prognostic factor despite preoperative chemoradiotherapy in esophageal adenocarcinoma

ObjectiveWe reviewed our experience with preoperative chemoradiotherapy in patients with adenocarcinoma of the distal esophagus and pretreatment endoscopic ultrasonography-identified celiac adenopathy.MethodsOne hundred eighty-six patients with adenocarcinoma of the distal esophagus were staged with endoscopic ultrasonography before treatment from 1997 through 2004. All patients were treated with concurrent chemoradiotherapy (CRT group) and surgical intervention or induction chemotherapy followed by concurrent chemoradiotherapy (C→CRT group) and surgical intervention. Survival analysis (excluding operative mortality) evaluated various pretreatment factors.ResultsMultivariable Cox regression analysis showed that pretreatment endoscopic ultrasonography-identified celiac adenopathy was a significant predictor of decreased long-term survival (P = .03). Median and 3-year survivals were 49 months and 54% in the endoscopic ultrasonography-identified cN0 M0 group (n = 65), 45 months and 56% in the endoscopic ultrasonography-identified cN1 M0 group (n = 96), and 19 months and 12% in the endoscopic ultrasonography-identified celiac adenopathy (cM1a) group (n = 18; P = .03). Increased systemic relapse was noted in the endoscopic ultrasonography-identified cM1a group (44% vs 22%, P = .07). The only factor associated with increased survival in the endoscopic ultrasonography-identified cM1a group (27 vs 15 months, P = .02) was the addition of induction chemotherapy before concurrent chemoradiotherapy and surgical intervention.ConclusionsEndoscopic ultrasonography-identified celiac adenopathy in patients with adenocarcinoma of the distal esophagus conveys a poor prognosis despite preoperative chemoradiotherapy. These patients should be stratified in future multimodality trials. The investigation of induction chemotherapy before concurrent chemoradiotherapy might be warranted in this high-risk group of patients

Digital Humanities in the iSchool

The interdisciplinary field known as digital humanities (DH) is represented in various forms in the teaching and research practiced in iSchools. Building on the work of an iSchools organization committee charged with exploring digital humanities curricula, we present findings from a series of related studies exploring aspects of DH teaching, education, and research in iSchools, often in collaboration with other units and disciplines. Through a survey of iSchool programs and an online DH course registry, we investigate the various education models for DH training found in iSchools, followed by a detailed look at DH courses and curricula, explored through analysis of course syllabi and course descriptions. We take a brief look at collaborative disciplines with which iSchools cooperate on DH research projects or in offering DH education. Next, we explore DH careers through an analysis of relevant job advertisements. Finally, we offer some observations about the management and administrative challenges and opportunities related to offering a new iSchool DH program. Our results provide a snapshot ofthe current state of digital humanities in iSchools which may usefully inform the design and evolution of new DH programs, degrees, and related initiatives