Sierra Nevada Journeys: Strategic Expansion Plan 2016

Sierra Nevada Journeys (SNJ) is an outdoor education organization that has grown substantially since its founding in 2006. The organization offers a variety of programs to students in California and Nevada, but currently lacks the infrastructure necessary to meet increased demand and provide optimal outdoor education experiences for its students. As the organization prepares to receive a large land donation from their parent organization, the Sierra Health Foundation, they reached out to the University of Michigan’s School of Natural Resources and Environment to receive guidance on how best to approach their expansion. Originally, the organization sought guidance in deciding how they should proceed with meeting increased demand, whether this should be completed through physical campus expansion or instead through curriculum expansion to host students throughout the year (later referred to as “winterization”). As the project evolved, the organization gained a better idea of its needs and available resources, including a future donation by Sierra Health Foundation of the land where Grizzly Creek Ranch (GCR), their 1,500-acre outdoor education learning center, is located. With this new information, they decided to proceed with a physical campus expansion that would allow them to better serve the students who attended programs at GCR and instructed us to explore this avenue for the expansion. In the new scenario, we aimed to provide a plan to enable SNJ to grow their programming through the addition of classroom space and curriculum, as well as an improved landscape design to match their educational needs. To begin shaping their recommendation, the team conducted background research to understand the history and trends in outdoor environmental education. After gaining in-depth knowledge of the area of interest, further research in the form of case studies and qualitative interviews were conducted with experts from best-in-class outdoor environmental education organizations from the United States and Canada. The results of this primary research included information on how environmental education center leaders utilized their classrooms, planned their expansions, embraced their mission, and implemented their curriculum. Pairing this newly acquired knowledge with our knowledge of SNJ’s needs and resources, we ultimately developed recommendations that included curriculum adjustments, landscape design to enhance environmental education programming, and types of structures that would not only meet their needs, but also help them to embrace their mission. The final recommendations provided by our team will propel the SNJ campus and the on-campus learning experience to the next level of outdoor education, and include 1) the addition of an indoor learning space (classroom) designed as a modular building with sustainability features and 2) a landscape design that includes the addition of physical features that both enhance current curriculum (e.g. forest ecology, pond ecology, water cycle) and also create opportunities for new curriculum (e.g. soil ecology, land forms, sustainability challenge, food cycle). We ultimately provided a design proposal that put SNJ’s mission of environmental education at the forefront. Each aspect of the recommendation puts SNJ’s mission first, offering a best case scenario without monetary or regulatory restrictions. Ultimately, the team was able to apply the perspective of their individual specialties (Landscape Architecture, Sustainable Systems, Behavior, Education and Communication) to provide a sustainability-driven solution to SNJ.Master of Science Master of Landscape ArchitectureNatural Resources and EnvironmentUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/117661/1/Sierra_Nevada_Journeys_MP.pd

Hyperon Production in Proton-Nucleus Collisions at 42 GeV Center of Mass Energy

The subject of this thesis is a measurement of hyperon production ratios which is of special interest as a reference on Quark Gluon Plasma search. The data used in this analysis have been taken with a minimum bias trigger at the fixed target experiment HERA-B, which uses the 920 GeV proton beam of the HERA storage ring at DESY. $\Lambda$, $\Xi$ and $\Omega$ hyperons produced in collisions using carbon and tungsten wires as targets were reconstructed. Hyperon ratios are presented for the rapidity range $-1.5 < y < 0.5$ (where they where measured), extrapolated to the whole phase space and to $y = 0$. The main results at $y = 0$ are $\frac{\overline{\Lambda}}{\Lambda} = 0.88 \pm 0.07$ (error including systematic error) and $\frac{\overline{\Xi}}{\Xi} = 0.69 \pm 0.12$ (statistical uncertainty only) for the carbon target. These values are compared to proton--nucleus and nucleus--nucleus data above and below HERA-B energies and are comparable with both. In the rapidity range $-1.5 < y < 0.5$ the ratio $\frac{\overline{\Lambda}}{\Lambda}$ is significantly different for the two target materials, whereas extrapolated to the whole phase space it is not. A possible explanation in terms of multiple scatterings in the nucleus is given. The distribution of the $\Lambda$ particle--anti-particle asymmetry versus Feynman's scaling variable $x_f$ using the carbon target is found to be in good agreement with measurements from pion--nucleus reactions at 500 GeV $\pi$-beam energy

Gravitational instability and fragmentation of self-gravitating accretion disks

We know from observations that supermassive black holes (SMBH) of masses up to 10^{10} \msol existed in quasars when the universe was only about $10^9$ years old. The rapid formation of SMBHs can be understood as the outcome of the collision of two large gas-rich galaxies followed by disk accretion. This model relies on a large enough turbulent viscosity in the disk. We show in a linear stability analysis of thin self-gravitating viscous disks that the gravitational instability can drive a turbulence generating the $\beta$-viscosity. For simulating a self-gravitating accretion disk in polar coordinates the hydrodynamics code NIRVANA2.0 is adapted for our needs which includes cooling. The results are disk fragmentation, strong accretion at the inner radial boundary of the calculation domain and strong outflow at the outer boundary which both come about by interactions between clumps. The accretion time scale for a disk mass of 6\ex{8} \msol in a radial extent of 29 \pc to 126 \pc is about 1.2\ex{7} \yr, corresponding to a viscosity parameter $\beta \approx 0.04$. We can confirm the $\beta$-viscosity interpretation by the turbulent velocity and length scale and by the scaling of the accretion time scale. All this supports the SMBH-formation model

Dissecting the role of selenothiol- versus thiol-based catalysis using the model enzyme glutathione peroxidase 4 (GPx4)

Selenocysteine (Sec) is the 21st amino acid. Unlike other amino acids incorporation of Sec into proteins is more complex by far as it is encoded by the opal stop codon UGA. A complex and highly sophisticated incorporation mechanism is required in order to assure the correct co-translational incorporation of Sec into the nascent polypeptide chain. Even after years of intensive research the question as to why selenoproteins are important for mammalian life has not been fully understood. This study aimed to provide answers to this question using gluthathione peroxidase 4 (GPx4) as a model enzyme. It has been shown that GPx4 is essential for early embryogenesis, neuro- and retina-protection and male fertility in mice. But the role of selenothiol- versus thiol-based GPx4 catalysis in cells and mice, as well as the role of the catalytic tetrad in GPx4 catalysis and the subcellular localisation of the different GPx4 isoforms and their impact on cell protection have remained unclear. Therefore, a series of mutant variants of GPx4 were generated by site-directed mutagenesis, stably expressed in tamoxifen-inducible GPx4 knockout cells (Seiler et al., Cell Metab 2008), and functionally analysed. GPx4 mutant variants included those of the peroxidatic Sec, the catalytic tetrad, the mitochondrial leader sequence (Mls) and the non-peroxidatic cysteines. These studies revealed that Cys can functionally replace Sec in the active centre of GPx4 to a large extent in cells, whereas some amino acids of the catalytic site are necessary for GPx4 function. None of the non-peroxidatic Cys were shown to be required for the cell-protective function of GPx4, ruling out a possible resolving Cys in the catalytic cycle of GPx4 unlike homologues in other organisms that use a resolving Cys. The fuction of a resolving Cys is to start a nucleophilic attack upon the intermolecular bond between the peroxidatic Cys and the substrate in order to create an intramolecular disulfidbride. Apparently subcellular localization of GPx4 in the extramitochondrial/cytosolic compartment is crucial for its cell death preventing qualities as overexpression of mitochondrial GPx4 in the knockout cells failed to rescue cell death induced by endogenous GPx4 disruption.Bei Selenocystein (Sec) handelt es sich um die 21igste Aminosäure. Im Gegensatz zu anderen Aminosäuren ist der Einbau von Selenocystein in die entstehende Polypeptidkette sehr viel komplexer, da Sec von dem Opal Stopcodon UGA codiert wird. Eine komplexe und hochentwickelte Maschinerie ist erforderlich um den korrekten, ko-translationalen Einbau von Sec in Proteine zu gewährleisten. Auch nach Jahren intensiver Forschung ist es immer noch weitgehend unklar, warum Selenoproteine für das Säugerleben unverzichtbar sind. Diese Studie hatte deshalb zum Ziel, diese Frage etwas genauer zu beleuchten, wobei die Glutathion-Peroxidase 4 (GPx4) als Modellenzym verwendet wurde. Es ist bekannt, dass GPx4 sowohl für die Embryonalentwicklung, den Schutz von Neuronen und der Retina sowie für die männliche Fertilität von Mäusen unverzichtbar ist. Dennoch sind viele Fragen bezüglich der Funktionsweise und möglicher Unterschiede von Selenothiol- zu Thiolbasierter GPx4 Katalyse in Zellen und Mäusen ungeklärt. Ebenso wie die genaue Funktion der katalytischen Tetrade bei der GPx4 Katalyse, und die subzellulare Lokalisation der verschiedenen GPx4 Isoformen und deren Einfluß auf den zellulären Schutz bislang ungeklärt sind. Deswegen wurden in dieser Arbeit eine Reihe von GPx4 Mutanten durch zielgerichtete Mutagenese erzeugt. Diese wurden stabil in Tamoxifen-induzierbaren GPx4 knockout Zellen (Seiler et al., Cell Metab 2008) exprimiert und auf ihre Funktionalität analysiert. Die verschiedenen GPx4 Mutationen beinhalteten Mutanten des Sec im aktiven Zentrum, der katalytischen Tetrade, der mitochondrialen Signalsequenz (Mls) sowie der nicht peroxidativen Cysteine. Die hier vorgelegten Untersuchungen zeigen, dass Cys in der Lage ist das Sec im aktiven Zentrum, unter Aufrechterhaltung eines Großteils der Funktionalität, in der Zelle zu ersetzen, wohingegen einige der Aminosäuren der katalytischen Tetrade unentbehrlich für die Funktionalität von GPx4 sind. Keines der übrigen, in GPx4 vorhandenen, Cys wurde benötigt, um die zelluläre Schutzwirkung von GPx4 aufrecht zu erhalten. Dieses Ergebnis schließt die Existenz eines auflösenden Cys im katalytischen Kreislauf von GPx4 aus. Dies steht im Gegensatz zu den Cys tragenden Homologen in anderen Organismen, welche über ein auflösendes Cys verfügen. Die Funktion des auflösenden Cys besteht darin, einen nukleophilen Angriff auf die intermolekulare Bindung zwischen dem peroxidativen Cys und dem Substrat zu starten. Durch diesen Angriff wird die intermolekulare Bindung in eine intramulekulare Disulfidbrücke umgewandelt. Die Lokalisation von GPx4 im extramitochondrialen/cytosolischen Raum ist zudem entscheidend für den Schutz vor Zelltod, da eine Überexpression der mitochondrialen GPx4 nicht in der Lage war, den durch Ausschalten der endogenen GPx4 verursachten Zelltod zu verhindern

Backpackers: the next generation?

New Zealand has a well-established network of accommodations, transportation, and visitor activities developed specifically for backpackers. These tourists account for almost ten percent of the country’s international visitor expenditure. To date, the majority of backpacker research has focussed on the traditional market segment of student and youth travellers, though a few quantitative studies have also researched the needs and preferences of older travellers using hostels and backpackers’ accommodations. Though more than 50 percent of New Zealand’s international visitors are over age 40, few currently stay at this type of accommodation. Using New Zealand as a case study, this thesis explores, qualitatively, the perspectives of older backpackers: their self-perceptions, their travel motivations, their needs and expectations in accommodation. In addition, it examines the points of view of the owners of small, independent backpackers’ accommodations to gain their perspectives on hosting a multi-generational clientele and on what the implications might be of expanding this market. Key findings show that older travellers who use backpackers’ accommodations technically meet all Pearce’s (1990) original definitions of “backpacker” – they prefer budget accommodations, they are socially interactive, they travel independently and flexibly, they travel for longer holidays than do most, and they choose informal and participatory activities. However, these travellers reject the self-definition of “backpacker”, an impasse that presents a lexical challenge to both scholars and tourism marketers. The final section addresses the impacts and implications of “backpacker” nomenclature on baby boomer travellers, academia, and the backpacker industry at large

Придушення бокових пелюсток автокореляційних функцій шумоподібних сигналів

Об’єкт розробки – шумоподібні сигнали. Предмет розробки – способи придушення бокових пелюсток автокореляційних функцій шумоподібних сигналів. Мета кваліфікаційної роботи – підвищення відношення сигнал-шум за основним піком автокореляційної функції за рахунок придушення тільки найбільш інтенсивних її бокових пелюсток до необхідного рівня. Наукова новизна полягає у використанні в запропонованому підході рекурентної ітераційної процедури між необхідним придушенням бокових пелюсток автокореляційних функцій і синтезом фізично реалізованого коригуючого фільтру зі збереженням початкової його смуги пропускання. У першому розділі проаналізовано основні типи та властивості шумоподібних сигналів, а також існуючі способи придушення (мінімізації) бокових пелюсток їх автокореляційних функцій. У спеціальній частині роботи розроблено підхід до придушення найбільш інтенсивних бокових пелюсток автокореляційних функцій шумоподібних сигналів з підвищенням відношення сигнал-шум та оцінено його ефективність. За наслідками досліджень зроблено висновки щодо рішення поставленої задачі. У економічному розділі виконані розрахунки капітальних витрат та трудомісткість розробки підходу до придушення найбільш інтенсивних бокових пелюсток автокореляційних функцій шумоподібних сигналів

A Gravitational Instability-Driven Viscosity in Self-Gravitating Accretion Disks

We derive a viscosity from gravitational instability in self-gravitating accretion disks, which has the required properties to account for the observed fast formation of the first super-massive black holes in highly redshifted quasars and for the cosmological evolution of the black hole-mass distribution.Comment: 14 pages, 1 figure, ApJ Letters (in press

Using Early Data to Illuminate the Pioneer Anomaly

Analysis of the radio tracking data from the Pioneer 10/11 spacecraft at distances between about 20 - 70 AU from the Sun has consistently indicated the presence of an unmodeled, small, constant, Doppler blue shift drift of order 6 \times 10^{-9} Hz/s. After accounting for systematics, this drift can be interpreted as a constant acceleration of a_P= (8.74 \pm 1.33) \times 10^{-8} cm/s^2 directed towards the Sun, or perhaps as a time acceleration of a_t = (2.92 \pm 0.44)\times 10^{-18} s/s^2. Although it is suspected that there is a systematic origin to this anomaly, none has been unambiguously demonstrated. We review the current status of the anomaly, and then point out how the analysis of early data, which was never analyzed in detail, could allow a more clear understanding of the origin of the anomaly, be it a systematic or a manifestation of unsuspected physics.Comment: 19 pages, 6 figures, 2 tables, additional materia

Backpacking through an ontology of becoming : a never‐ending cycle of journeys

By adopting an ontological stance of becoming, this study traces qualitatively the journeys of contemporary backpacker tourists using the theoretical construct of the 'Hero's Journey' as a conceptual vehicle. This process allows for the development of a cyclical model of experience that illustrates the backpacker's experience in three stages of departure, initiation and return. This approach reveals the role that former backpackers play through the sharing of knowledge and the invaluable support they offer to novice backpackers through a network of support that is available to contemporary backpackers who choose to follow established backpacking trails. This never ending cycle of journeys becomes instrumental into the shaping of what this paper see as the common, collective consciousness of the backpacking experience and the evolution of the backpacking experience market