X Ray, Far, and Extreme Ultraviolet Coatings for Space Applications

The idea of utilizing imaging mirrors as narrow band filters constitutes the basis of the design of extreme ultraviolet imagers operating at 58.4 nm and 83.4 nm. The net throughput of both imaging-filtering systems is better than 20 percent. The superiority of the EUV self-filtering camera/telescope becomes apparent when compared to previously theoretically designed 83.4-nm filtering-imaging systems, which yielded transmissions of less than a few percent and therefore less than 0.1 percent throughput when combined with at least two imaging mirrors. Utilizing the self-filtering approach, instruments with similar performances are possible for imaging at other EUV wavelengths, such as 30.4 nm. The self-filtering concept is extended to the X-ray region where its application can result in the new generation of X-ray telescopes, which could replace current designs based on large and heavy collimators

Mr. James Sheppard on Education and Employment

You can listen to the full interview and read a transcript HERE. James Sheppard was born in New York City in 1924, to parents who had just emigrated from Antigua. He was the eldest of four siblings. He graduated high school in 1942, and served in the Army during World War II. He worked as an aviation mechanic after the war; in 1957 he was hired by the Federal Aviation Administration as an inspector, a job he continued until he retired in 1985. He married twice, and had five children and seven grandchildren. His family moved to Westbrook, Maine, in 1971, when the FAA transferred him to work at the Portland Jetport. He was an active member of the Lions Club, and mentored local students. He discusses raising children, his family history in the Caribbean, discrimination he has faced as an African American throughout his life, Portland’s growing community of African immigrants, and cultural differences between Maine and New York City. Mr. James Sheppard on Education and Employment “My experiences raising children? Well, seeing to it that they attended school and seeing to it that they did their homework. That sort of thing. That\u27s standard I guess; regular stuff, I guess. I don\u27t know how to answer that. Between my wife and I, we saw to it that they did a lot of reading. And we did a lot of traveling. We did a lot of traveling to the Caribbean and South America, and we took them with us. In addition to seeing to it that they did their work at school. And they excelled, especially the one that\u27s a professor now. The youngest one gained. You know, you learn a lot. You don\u27t know anything with your first son; you get better as you have more children. By the time number five was born, we knew exactly how to channel things. And I think that\u27s why he came out number one. With my first son, I didn\u27t learn anything. [laughter] I shouldn\u27t say that; he\u27s the horticulturalist in New York.”https://digitalcommons.usm.maine.edu/we5quotes/1017/thumbnail.jp

Sheppard, James

James Sheppard was born in New York City in 1924, to parents who had just emigrated from Antigua. He was the eldest of four siblings. He graduated high school in 1942, and served in the Army during World War II. He worked as an aviation mechanic after the war; in 1957 he was hired by the Federal Aviation Administration as an inspector, a job he continued until he retired in 1985. He married twice, and had five children and seven grandchildren. His family moved to Westbrook, Maine, in 1971, when the FAA transferred him to work at the Portland Jetport. He was an active member of the Lions Club, and mentored local students. He discusses raising children, his family history in the Caribbean, discrimination he has faced as an African American throughout his life, Portland’s growing community of African immigrants, and cultural differences between Maine and New York City.https://digitalcommons.usm.maine.edu/aa_hiwimi/1013/thumbnail.jp

Locomotor-Cognitive Dual-Tasking in Children with and without Developmental Coordination Disorder

Aetiological accounts recognise the impairment in predictive motor control and cognitive control, as evident in children with Developmental Coordination Disorder (DCD). Given that DCD is defined by a deficit in the development of motor skills, the broad aim of this thesis was to investigate the current underlying explanations for compromised predictive motor control and cognitive control in DCD and its implications for dual-tasking using a hybrid approach. Cognitive control, synonymous with executive functioning, includes a complex set of neurocognitive and self-regulatory processes, which include attention, and inhibitory control, cognitive flexibility, working memory, and processing speed. These abilities are divided into shifting, updating, and inhibiting components which accumulate into the ability to plan, reason and problem-solve goal-directed actions. Researchers theorise the intertwined nature of cognitive control and predictive motor control as they are both developed in early life and work to reach a mutual goal of action control. Predictive motor control encompasses the ability to estimate the dynamics of limb trajectory, anticipate consequences, rapidly control movements in real-time and internally model behaviour. The capacity to predictively control movements may have a neural underpinning and exists as one of the core deficits of DCD. This predictive control deficit creates various challenges for children with DCD when confronting novel tasks, especially those that require the ability to complete two tasks at once. Dual-tasking is vital for human behaviour and involves the parallel performance of two tasks with distinct goals, the outcome of which can be measured separately. Dual-task performance is typically assessed by the concurrent performance of a motor and cognitive task (e.g., walking by responding to an auditory stimulus). For a child to successfully dual-task they require an ability to share cognitive resources between tasks, enlist control of cognitive functions, prioritise tasks, and automatise motor skills to maintain safety. Therefore, dual-task paradigms are a valuable method of assessing the integration of motor and cognitive control in real time. In light of known deficits, the experimental assessment of dual-task performance was predicted to reveal dual-task performance impairments for children with DCD compared to their typically developing (TD) peers.   Study 1 comprises a systematic review and meta-analysis of literature on the latest behavioural and neuroimaging research to clarify the underlying mechanisms and neurocognitive basis of DCD (Chapter 2). This review established fundamental deficits for those with DCD in areas of integration, including visual-motor and cognitive-motor integration. The interpretations of these results highlight that those with DCD may aim to reduce uncertainty by visually guiding each phase of the movement with shorter gaze targets and more frequent fixations than their typical peers. Greater dual-task costs for those with DCD compared to TD peers were also found across locomotor and manual tasks. Patterns of dual-task performance were understood to demonstrate evidence of poor motor skill automatization and, thus, an energy-intensive approach to motor planning and control, which reduced the capacity to share cognitive resources towards an additional task. The reduced automatization, paired with pervasive deficits in cognitive control, particularly during tasks that demand an efficient response or response inhibition is predicted to underlie these areas of difficulty across visual-motor and cognitive-motor integration. Consistent with prior research, individuals with DCD exhibited increased motor variability compared to their TD peers, as evidenced by cautious walking patterns and slower manual control movements. Greater motor variability for individuals with DCD was discussed in light of adaptive benefits (reduced risk of injury) and implications for safety under specific conditions, such as road crossing. Continued areas of exploration were highlighted for cognitive-motor integration as a potential area of impairment in DCD. Thus, this meta-analytical review demonstrated the need for a well-developed dual-task paradigm to explore the underlying areas of potential deficit in DCD. Study 2 examined locomotor-cognitive dual-task performance in children with and without DCD (6-12 years) (Chapter 6). The participants were required to walk along a straight 12m path and completed a cognitive visual discrimination task at two levels of complexity under single and dual-task conditions. As this study was exploratory, various cognitive and motor metrics were included to explore performance differences. Standard evaluation of dual-task interference (proportional dual-task cost - pDTC) showed that TD children spent a greater proportion of time in double support while dual-tasking. In contrast, children with DCD walked faster when dual-tasking. Within-trial comparison of gait (using proportional within-trial costs - p-WTC) showed that both the TD and DCD groups walked slower before presentation of the cognitive task compared to after the task. Children with DCD showed this pattern for simple and complex cognitive stimuli, whereas for the TD group, it was only confined to the simple condition. Across both typically developing and children with DCD, a potential expectancy effect was observed in relation to the impending cognitive task. The findings of this study were interpreted to reflect the specific task factors, methodology of the chosen dual-task paradigm and participant sample of developing children. Of particular clinical relevance, this research demonstrates how children with DCD can successfully dual-task similarly to their TD peers when their visual systems are not constrained. This study highlighted the need to consider forward modelling (predictive motor control), a known area of deficit in DCD within a dual-task paradigm, to probe the limits of performance in children with DCD. Study 3 (Chapter 7) extended on the findings of Study 2 by examining locomotor-cognitive obstacle negotiation using an augmented reality dual-task paradigm. The same participants were included in both Study 2 and Study 3. During the Study 3 paradigm, the participants were required to walk along a straight 12m path, step over an obstacle (low and high) at the mid-point while completing the cognitive visual discrimination task (simple and complex), and then walk to the end of the pathway. The findings of this study demonstrated a similar pattern to Study 2, with greater costs on the motor rather than the cognitive outcomes across groups and task combinations. Performance costs are seen across cognitive and gait metrics with the most substantial costs observed at the point of obstacle step-over, seen by leading leg clearance. At the obstacle step-over phase, the DCD group in particular, were observed to negotiate over the obstacle with consistently larger clearance margins and adopted this pattern before their TD peers. The findings of this study established that a complex motor task (obstacle negotiation) appears to be an underlying challenge for children with DCD and that both groups were similarly impaired by the challenging cognitive task while negotiating an obstacle. Future research is suggested to consider task conditions such as challenging terrain or precise stepping and measure vision and visual tracking to examine potential area of difficulty for children with DCD. By assessing dual-task performance under conditions that involve reduced opportunities for motor planning, greater difficulties may be observed for children with DCD.   In sum, the overall findings have supported the aims of this thesis by reviewing the current mechanism-focused research in DCD and assessing the implications for cognitive-motor interference. A hybrid approach to dual-task performance was adopted to improve the rigour and relevance of tasks to a population of children with DCD. The novelty of the dual-task paradigm was seen in the use of an augmented-reality headset to present a newly created discrete cognitive paradigm. Both single, dual, proportional dual-task costs and proportional within-task costs were assessed across various task metrics to provide an exploratory overview of how dual-task performance may differ for children with DCD. Thus, the findings of the two experimental studies have progressed the specificity and relevance of dual-task designs and improved our knowledge of differences in DCD. When children completed dual-task paradigms, those with DCD performed similarly to their typical peers when pairing involved the relatively simple motor task of locomotion. As the motor task demands efficient predictive motor control (high obstacle negotiation), dual-task performance costs on obstacle clearance metrics were greater for the DCD group. Whilst inconsistent group differences were found, the innovative dual-task paradigm demonstrates an effect of cognitive task demands that is observable at discrete points of the motor task. The findings of this body of work highlight that those with DCD are able to perform similarly to typically developing children under simple motor task demands, and during increasingly challenging obstacle negotiation demands, they may adaptively compensate for their known difficulties in predictive motor control. In sum, future research is recommended to explore dual-task paradigms with increasingly complex motor task conditions that also consider visuomotor integration for children with DCD. With this knowledge, we can inform the continued evolution of theory, assessment and clinical intervention

Mr. James Sheppard on Leisure

Interviewer: Sanela Zukic Interviewee: Mr. James Sheppard (born in New York City in 1924; both his parents immigrated from Antigua in the West Indies to Canada, then they came to the United States in 1923; moved to Maine in 1971). “But in addition to that we\u27d have lots of summer events: picnics and that sort. But that\u27s separate; that\u27s a different thing.” “Between my wife and I, we saw to it that they did a lot of reading. And we did a lot of traveling. We did a lot of traveling to the Caribbean and South America, and we took them with us.” “We\u27re spread out so far around, we\u27re spread out so much so that we have little reunions, little itty baby reunions. This past Christmas, my wife and I went down to Antigua, the same place where my parents were born. And while we were there we spent two weeks gathering all our relatives together, and we all got together on Christmas Day. We went down there at Christmas. I have one aunt that\u27s still alive; she was born in maybe 1915-somewhere around there. So she\u27s still alive, up there in age. And the cousins, their children. I have a lot of cousins there in the Caribbean. And we had a couple of get-togethers down there. Christmas and that. We plan to do it again this year. Whenever any of them travel to the United States, we try to set up a date where we can get together and everyone can see each other. So we do have that sort of family reunion. But they\u27re not formal. These aren\u27t things when you send letters out a some families do. They have reunions in nice, you know, rented places, ballrooms, and all that sort of thing. But we don\u27t do that.”https://digitalcommons.usm.maine.edu/we4_leisurequotes/1003/thumbnail.jp

Emigration der bosnischen Jugend als Gegenwartsphänomen

Emigration der bosnischen Jugend kann als Postkriegszeitphänomen gesehen werden. Autorin entschied sich diesen Phänomen durch die empirische Studie an bosnischen Studierenden in Wien, nachzugehen. Sie sollte als Grundlage für die erleichterte und erfolgreiche Integration dienen

VUV thin films, chapter 7

The application of thin film technology to the vacuum ultraviolet (VUV) wavelength region from 120 nm to 230 nm has not been fully exploited in the past because of absorption effects which complicate the accurate determination of the optical functions of dielectric materials. The problem therefore reduces to that of determining the real and imaginary parts of a complex optical function, namely the frequency dependent refractive index n and extinction coefficient k. We discuss techniques for the inverse retrieval of n and k for dielectric materials at VUV wavelengths from measurements of their reflectance and transmittance. Suitable substrate and film materials are identified for application in the VUV. Such applications include coatings for the fabrication of narrow and broadband filters and beamsplitters. The availability of such devices open the VUV regime to high resolution photometry, interferometry and polarimetry both for space based and laboratory applications. This chapter deals with the optics of absorbing multilayers, the determination of the optical functions for several useful materials, and the design of VUV multilayer stacks as applied to the design of narrow and broadband reflection and transmission filters and beamsplitters. Experimental techniques are discussed briefly, and several examples of the optical functions derived for selected materials are presented

Myths of and obstacles in teaching entrepreneurship in Bosnia-Herzegovina and beyond

Podučavanje poduzetništva je postala popularna politička alternativa koja daje nadu za poboljšanja u ekonomiji, uključujući I smanjenu nezaposlenost. Nažalost ne postoji dovoljno dokaza sa lokalnog I regionalnog nivoa da je to stvarno tako, posebno imajući u vidu neadekvatne kapacitete za kreiranje politika, monitoring I evaluaciju ishoda te primijenjena istraživanja. Također postoje indikacije da se poduzetništvo koristi I kao mjera socijalne politike. Podučavanje u širem smislu, kao I podučavanje poduzetništva je sistemski zanemareno, uključujući koji sadrža jtreba imože da se podučava I kako, od koga, komu, te koji su realni ishodi. Sve ovo, plus vrlo nisko učešće odraslih u procesima stjecanja znanja ostavlja dosta nerazjašsnjenih pitanja I problema. Sistemski problem kao što je obrazovanje nastavnog kadra se ne mogu zanemarivati, kao niti mnoge relevantne istrazivačke teme sa lokalnim I regionalnim kontekstom.Teaching entrepreneurship has become a popular policy intervention that raises hopes for improved economic performance, including lower unemployment. Unfortunately there is no sufficient local and regional evidence that supports these expectations, in part because of substandard policy-making, monitoring and evaluation, and applied research capabilities. Furthermore, there are indications entrepreneurship is also being used as a social policy intervention, thereby generating different outcomes. Teaching in broader sense, as well as entrepreneurially-focused teaching has been neglected, including which content is to be taught and how, by whom, to whom, and what are likely long-term outcomes. All of this, combined with low adult learning participation rates, leaves many educational challenges unrecognized and unresolved. Without addressing systemic issues such as teacher training, any initiatives are likely to have only temporary, if any positive effects

X ray, extreme and far ultraviolet optical thin films for space applications

Far and extreme ultraviolet optical thin film filters find many uses in space astronomy, space astrophysics, and space aeronomy. Spacebased spectrographs are used for studying emission and absorption features of the earth, planets, sun, stars, and the interstellar medium. Most of these spectrographs use transmission or reflection filters. This requirement has prompted a search for selective filtering coatings with high throughput in the FUV and EUV spectral region. Important progress toward the development of thin film filters with improved efficiency and stability has been made in recent years. The goal for this field is the minimization of absorption to get high throughput and enhancement of wavelength selection. The Optical Aeronomy Laboratory (OAL) at the University of Alabama in Huntsville has recently developed the technology to determine optical constants of bulk and film materials for wavelengths extending from x-rays (0.1 nm) to the FUV (200 nm), and several materials have been identified that were used for designs of various optical devices which previously have been restricted to space application in the visible and near infrared. A new design concept called the Pi-multilayer was introduced and applied to the design of optical coatings for wavelengths extending from x-rays to the FUV. Section 3 of this report explains the Pi-multilayer approach and demonstrates its application for the design and fabrication of the FUV coatings. Two layer Pi-stacks have been utilized for the design of reflection filters in the EUV wavelength range from 70 - 100 nm. In order to eliminate losses due to the low reflection of the imaging optics and increase throughput and out-of-band rejection of the EUV instrumentation we introduced a self-filtering camera concept. In the FUV region, MgF2 and LiF crystals are known to be birefringent. Transmission polarizers and quarterwave retarders made of MgF2 or LiF crystals are commercially available but the performances are poor. New techniques for the design of the EUV and FUV polarizers and quarterwave retarders are described in Section 5. X- and gamma-ray detectors rely on a measurement of the electron which is effected when a ray interacts with matter. The design of an x- and gamma-ray telescope to operate in a particular region of the spectrum is, therefore, largely dictated by the mechanism through which the rays interact. Energy selection and the focusing of the incident high energy rays can be achieved with spectrally selective high reflective multilayers. The design and spectral performance of narrowband reflective x-ray Pi-multilayers are presented in section 6