2,789 research outputs found
Using an agent-based, object-oriented model to test the performance of catch per unit of effort as an estimator of fish abundance in small-scale, multispecies fisheries
Non-field-aligned Proton Beams and Their Roles in the Growth of Fast Magnetosonic/Whistler Waves: Solar Orbiter Observations
The proton beam is an important population of the non-Maxwellian proton velocity distribution in the solar wind, but its role in wave activity remains unclear. In particular, the velocity vector of the proton beam and its influence on wave growth/damping have not been addressed before. Here we explore the origin and the associated particle dynamics of a kinetic wave event in the solar wind by analyzing measurements from Solar Orbiter and comparing them with theoretical predictions from linear Vlasov theory. We identify the waves as outward-propagating circularly polarized fast magnetosonic/whistler (FM/W) waves. The protonâs velocity distribution functions can destabilize FM/W waves. According to linear Vlasov theory, the velocity fluctuations of the core and the beam associated with FM/W waves render the original field-aligned background drift velocity non-field-aligned. This non-field-aligned drift velocity carrying the information of the velocity fluctuations of the core and the beam is responsible for the wave growth/damping. Specifically, for the FM/W waves we analyze, the non-field-aligned fluctuating velocity of the beam population is responsible for the growth of these unstable waves in the presence of a proton beam. In contrast, the core population plays the opposite role, partially suppressing the wave growth. Remarkably, the observed drift velocity vector between the core and the beam is not field aligned during an entire wave period. This result contrasts the traditional expectation that the proton beam is field aligned
This Other Eden: Exploring a Sense of Place in Twentieth-Century Reconstructions of Australian Childhoods
This thesis explores the sense of place formed during childhood, as remembered by adult Australians who reconstruct their youth through various forms of life writing. While Australian writers do utilize traditional tropes of Western autobiography, such as the mythology of Eden and the Wordsworthian image of the child communing with Nature, these themes are frequently transformed to meet a uniquely Australian context. Isolation and distance from Europe, and the apparent indifference of our landscape towards white settlement, have received much critical attention in Australian studies generally and, indeed, broadly influence the formation of childrenâs sense of place across the continent. However, writers are also concerned with the role of place on a more local level. Through a comparison of writing from Western Australia, Queensland and Victoria, this thesis explores regional landscape preoccupations that create an awareness of local identity, variously contributing to or frustrating the childâs sense of belonging. Western Australian writing is dominated by images of isolation, the fragility of white settlement in a dry land lacking fresh water, and a pervasive beach culture. A strong sense of the littoral pervades writing from this region. Queenslandâs frontier mythology is of a different flavour: warm and tropical, nature here is exuberant, constantly threatening to overwhelm culture, already perceived as transient due to the flimsy aspect of the âQueenslanderâ house. Writing from Victoria, to some extent, tends to more closely follow English models, juxtaposing country and city environments, although there is a distinctly local flavour to many representations of urban Melbourne and its flat, grid-like organization. As Australian society becomes more concentrated on the coastal fringe, the beach is an increasingly significant environment. Though more prominent in writing from some regions than others, coastal imagery broadly reflects the modern Australianâs sense of inhabiting a liminal zone with negotiable boundaries
An Unusual Triad in Pediatric Neurology:A Case Report on Cerebral Palsy, Epilepsy, and Duchenne Muscular Dystrophy
We present a case of an unusual triad in pediatric neurology: a currently 12-year-old boy with cerebral palsy and epilepsy who was later also diagnosed with Duchenne muscular dystrophy. We describe the clinical path that resulted in this exceptional diagnosis. This case report illustrates how different neurological disorders may overshadow each other. In addition, it demonstrates that every child with cerebral palsy and either an atypical clinical course or with inexplicable laboratory values-as well as every infant boy born to a theoretical Duchenne muscular dystrophy carrier-should be subjected to additional investigations.</p
Pulmonary Sarcoidosis
Background: A 34-year-old male teacher was referred to the hospital with a persisting dry cough and dyspnea on exercise since eight weeks. He had no fever, neither complaints of ear, nose or throat. There were no complaints during the night. He had been a smoker until four months before presentation (12 pack years). At work a student was diagnosed with pulmonary tuberculosis, but the Mantoux and Quantiferon tests were negative. Physical examination was normal, without fever, lymphadenopathy or auscultation abnormalities. Laboratory investigation revealed a C-reactive protein of 2 mg/L. Pulmonary function testing showed a slight restriction. Immunological bronchial alveolar lavage (BAL) was rich of cells, especially T-lymphocytes of the CD4 type. CD4+/CD8+ ratio of the BAL was raised to 4.2, compared to a ratio of 2.4 in blood. There were no eosinophils found in the BAL. Conventional chest radiographs were performed, and showed multiple areas of consolidation in the bilateral lung fields, predominantly on the right side
Kinetic Features of Alpha Particles in a Pestchek-like Magnetic Reconnection Event in the Solar Wind Observed by Solar Orbiter
The acceleration and heating of solar wind particles by magnetic reconnection are important mechanisms in space physics. Although alpha particles (4He2+) are the second most abundant population of solar wind ions, their kinetic behavior in solar wind magnetic reconnection is not well understood. Using the high-energy (1500â3000 eV) range of the Solar Wind Analyser/ProtonâAlpha Sensor instrument on board Solar Orbiter, we study the kinetic features of alpha particles in an exhaust region of a Pestchek-like solar-wind reconnection event with a weak guide field. A pair of back-to-back compound discontinuities is observed in the exhaust region. We find that the plasma in the magnetic exhaust region is heated and bounded by slow shocks (SSs), while the accelerated reconnection jet is bounded by rotational discontinuities (RDs). The SSs are outside the RDs, which is not expected from the magnetohydrodynamical prediction. We suggest this different location of the discontinuities is due to the enhanced parallel temperature Tpâ„ > Tpâ„, which reduces the local AlfvĂ©n speed in the exhaust region, allowing the SSs to propagate faster than the RDs. Inside the exhaust region, the guide field is dominant. We find a two-population distribution of the alpha particles. These two populations are field aligned downstream the SSs and shift to have a perpendicular offset in the reconnection jet, suggesting that the change of the magnetic field at the RDs has similar timescales with the proton gyroperiod, but faster than those of the alpha particles, such that the alpha particles behave like pickup ions
Major flaws in conflict prevention policies towards Africa : the conceptual deficits of international actorsâ approaches and how to overcome them
Current thinking on African conflicts suffers from misinterpretations oversimplification, lack of focus, lack of conceptual clarity, state-centrism and lack of vision). The paper analyses a variety of the dominant explanations of major international actors and donors, showing how these frequently do not distinguish with sufficient clarity between the âroot causesâ of a conflict, its aggravating factors and its triggers. Specifically, a correct assessment of conflict prolonging (or sustaining) factors is of vital importance in Africaâs lingering confrontations. Broader approaches (e.g. âstructural stabilityâ) offer a better analytical framework than familiar one-dimensional explanations. Moreover, for explaining and dealing with violent conflicts a shift of attention from the nation-state towards the local and sub-regional level is needed.Aktuelle Analysen afrikanischer Gewaltkonflikte sind hĂ€ufig voller Fehlinterpretationen (Mangel an Differenzierung, Genauigkeit und konzeptioneller Klarheit, Staatszentriertheit, fehlende mittelfristige Zielvorstellungen). Breitere AnsĂ€tze (z. B. das Modell der Strukturellen StabilitĂ€t) könnten die Grundlage fĂŒr bessere Analyseraster und Politiken sein als eindimensionale ErklĂ€rungen. hĂ€ufig differenzieren ErklĂ€rungsansĂ€tze nicht mit ausreichender Klarheit zwischen Ursachen, verschĂ€rfenden und auslösenden Faktoren. Insbesondere die richtige Einordnung konfliktverlĂ€ngernder Faktoren ist in den jahrzehntelangen gewaltsamen Auseinandersetzungen in Afrika von zentraler Bedeutung. Das Diskussionspapier stellt die groĂe Variationsbreite dominanter ErklĂ€rungsmuster der wichtigsten internationalen Geber und Akteure gegenĂŒber und fordert einen Perspektivenwechsel zum Einbezug der lokalen und der subregionalen Ebene fĂŒr die ErklĂ€rung und Bearbeitung gewaltsamer Konflikte
Fiskalische Kosten einer steuerlichen Förderung von Forschung und Entwicklung in Deutschland - Eine empirische Analyse verschiedener Gestaltungsoptionen
Der Beitrag berechnet die AufkommensausfĂ€lle verschiedener Gestaltungsmodelle fĂŒr eine steuerliche Forschungsförderung in Deutschland auf Basis eines Mikrosimulationsmodells. Die fiskalischen Kosten betragen zwischen 464 Mio. ⏠und 5.701 Mio. âŹ. Eine Erstattungsoption der Steuergutschrift ĂŒber die Gewerbe- und Körperschaftsteuerschuld hinaus ist unerlĂ€sslich, da sonst etwa ein Drittel der Unternehmen nicht oder nur teilweise in den Genuss der Förderung kommen wĂŒrde und sich dadurch starke Verzerrungen zwischen ertragsstarken und ertragsschwachen Unternehmen ergeben. Eine Differenzierung der FördersĂ€tze fĂŒr KMU und groĂe Unternehmen kann die AufkommensausfĂ€lle wirksam begrenzen. Eine Kappungsgrenze in Höhe eines absoluten Betrages ist wegen der Verzerrungen innerhalb der Gruppe groĂer Unternehmen ungĂŒnstig. Als besonders pragmatisch erscheint eine Verrechnung der Steuergutschrift mit der abzufĂŒhrenden Lohnsteuer
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