Hydropower-induced land use change in Fincha's watershed, werstern Ethiopia: analysis and impacts

The present article analyzes the land use dynamics caused by hydropower dam construction in 1973 in the Fincha'a watershed (1318 km2), a tributary of the Blue Nile. Aerial photos (1957 and 1980) and an ASTER satellite image of 2001 were used to make 3 land use maps of the watershed using a geographic information system (GIS). The 239-km2 water reservoir inundated 100 km2 of grazing land, 120 km2 of swamp, 18 km2 of cropland, and 1.2 km2 of forestland. In 2001, cropland covered 77% of the land potentially available for community use, indicating that there is hardly any free land available for expansion to accommodate new farmers. Relocated communities operate on relatively small parcels of land situated either on steep slopes or in flood-prone areas. Consequently, they exhaustively utilize the trees available on their holdings, and convert grassland and bush-land to cropland, without applying sufficient soil conservation measures. Farmers resettled at or near bodies of water and swamps, however, are affected by seasonal fluctuations of water levels that very often inundate croplands, grazing land, and homes. The demand for cropland and grazing land is increasing as reservoir and swamp areas expand and new families are created. Soil erosion in steep areas can no longer be reduced in the traditional farming system. These enforced land use changes, combined with a lack of appropriate land management practices, may increase erosion and reservoir sedimentation. This could affect food security and electric power production in the near futur

Anthony\u27s Silence: The Intersection of Sex, Gender and Race in \u3cem\u3eDesigning Women\u3c/em\u3e

Editor\u27s Note: Lynn H. Turner and Helen Sterk examine one small part of the Designing Women script, a short speech by Anthony (one of the series\u27 regulars). They argue that, as the only African American male in the series, Anthony was in a unique position to examine the gender and race issues posed by the Thomas/Hill hearings, and by the Thomas nomination itself. Calling on writings by African .American scholars commenting on the Senate hearings and on race and gender issues generally, the authors conclude that the structure of Anthony\u27s speech represents a missed opportunity

Quantitative recurrence statistics and convergence to an extreme value distribution for non-uniformly hyperbolic dynamical systems

For non-uniformly hyperbolic dynamical systems we consider the time series of maxima along typical orbits. Using ideas based upon quantitative recurrence time statistics we prove convergence of the maxima (under suitable normalization) to an extreme value distribution, and obtain estimates on the rate of convergence. We show that our results are applicable to a range of examples, and include new results for Lorenz maps, certain partially hyperbolic systems, and non-uniformly expanding systems with sub-exponential decay of correlations. For applications where analytic results are not readily available we show how to estimate the rate of convergence to an extreme value distribution based upon numerical information of the quantitative recurrence statistics. We envisage that such information will lead to more efficient statistical parameter estimation schemes based upon the block-maxima method.Comment: This article is a revision of the previous article titled: "On the convergence to an extreme value distribution for non-uniformly hyperbolic dynamical systems." Relative to this older version, the revised article includes new and up to date results and developments (based upon recent advances in the field

Symmetries in the Lorenz-96 model

The Lorenz-96 model is widely used as a test model for various applications, such as data assimilation methods. This symmetric model has the forcing $F\in\mathbb{R}$ and the dimension $n\in\mathbb{N}$ as parameters and is $\mathbb{Z}_n$ equivariant. In this paper, we unravel its dynamics for $F<0$ using equivariant bifurcation theory. Symmetry gives rise to invariant subspaces, that play an important role in this model. We exploit them in order to generalise results from a low dimension to all multiples of that dimension. We discuss symmetry for periodic orbits as well. Our analysis leads to proofs of the existence of pitchfork bifurcations for $F<0$ in specific dimensions $n$: In all even dimensions, the equilibrium $(F,\ldots,F)$ exhibits a supercritical pitchfork bifurcation. In dimensions $n=4k$, $k\in\mathbb{N}$, a second supercritical pitchfork bifurcation occurs simultaneously for both equilibria originating from the previous one. Furthermore, numerical observations reveal that in dimension $n=2^qp$, where $q\in\mathbb{N}\cup\{0\}$ and $p$ is odd, there is a finite cascade of exactly $q$ subsequent pitchfork bifurcations, whose bifurcation values are independent of $n$. This structure is discussed and interpreted in light of the symmetries of the model.Comment: 31 pages, 9 figures and 3 table

Magnon contribution to unidirectional spin Hall magnetoresistance

We develop a model for the magnonic contribution to the unidirectional spin Hall magnetoresistance (USMR) of heavy metal/ferromagnetic insulator bilayer films. We show that diffusive transport of Holstein-Primakoff magnons leads to an accumulation of spin near the bilayer interface, giving rise to a magnoresistance which is not invariant under inversion of the current direction. Unlike the electronic contribution described by Zhang and Vignale [Phys. Rev. B 94, 140411 (2016)], which requires an electrically conductive ferromagnet, the magnonic contribution can occur in ferromagnetic insulators such as yttrium iron garnet. We show that the magnonic USMR is, to leading order, cubic in the spin Hall angle of the heavy metal, as opposed to the linear relation found for the electronic contribution. We estimate that the maximal magnonic USMR in Pt|YIG bilayers is on the order of $10^{-8}$, but may reach values of up to $10^{-5}$ if the magnon gap is suppressed, and can thus become comparable to the electronic contribution in, e.g., Pt|Co. We show that the magnonic USMR at a finite magnon gap may be enhanced by an order of magnitude if the magnon diffusion length is decreased to a specific optimal value that depends on various system parameters.Comment: 9 pages, 7 figure

Narrative Analysis of Sexual Etiquette in Teenage Magazines

Expanding on existing research on women\u27s magazines, this essay examines the sexual etiquette developed in advice columns in magazines popular among teenage women. Over a span of 20 years, the advice has changed very little. Serving the rhetorical function of field guides and training manuals, teen magazines limit women\u27s sociality and sexuality within narrowly defined heterosexual norms and practices. The rhetoric of sexual etiquette encourages young women to be sex objects and teachers of interpersonal communication rather than lovers, friends, and partners. Young women are being taught to subordinate self for others and to be contained

Do more banking offices mean more banking services?

An argument that recent growth in the number of banking offices (head offices plus their branches) does not necessarily mean that banking services have increased.Banks and banking - Customer services

Transport in developing countries and climate policy: suggestions for a Copenhagen agreement and beyond

Also in the global South, transport already significantly contributes to climate change and has high growth rates. Further rapid motorisation of countries in Asia and Latin America could counteract any climate efforts and aggravate problems of noxious emissions, noise and congestion. This Paper aims at connecting the need for transport actions in developing countries to the international negotiations on a post-2012 climate change agreement. It outlines the decisions to be taken in Copenhagen and the preparations to adequately implement these decisions from 2013. Arguing, that a sustainable transport approach needs to set up comprehensive policy packages, the paper assesses the substance of current climate negotiations against the fit to sustainable transport. It concludes that the transport sector's importance should be highlighted and a significant contribution to mitigation efforts required. Combining the two perspectives lead to several concrete suggestions: Existing elements of the carbon market should be improved (e.g. discounting), but an upscale of the carbon market would not be an appropriate solution. Due to a lack of additionality, offsetting industrialised countries' targets would finally undermine the overall success of the climate agreement. Instead, a mitigation fund should be established under the UNFCCC and financed by industrialised countries. This fund should explicitly enable developing countries to implement national sustainable development transport and mobility policies as well as local projects. While industrialized countries would set up target achievement plans, developing countries should outline low carbon development strategies, including a section on transport policy. -- Die rasante Motorisierung Asiens und Lateinamerikas könnte die Klimaschutzerfolge konterkarieren. Bis 2030, so Prognosen der IEA, werden im Verkehrssektor 2,5 Gigatonnen CO2 mehr emitiert als heute; 80 Prozent davon in den Ländern des Südens. Das Papier soll die Notwendigkeit verdeutlichen, dass in den Entwicklungsländern im Verkehrssektor heute schon Maßnahmen ergriffen werden müssen und die Klimaverhandlungen für die Post-Kyoto-Phase eine wichtige Gelegenheit sind. Die Ansätze in den gegenwärtigen Klimaverhandlungen werden den Anforderungen einer nachhaltigen Verkehrspolitik gegenübergestellt und dafür plädiert, den Stellenwert des Verkehrssektors zu den Klimaschutzanstrengungen zu erhöhen. Dafür werden mehrere konkrete Vorschläge gemacht: So sollten vorhandene Elemente des Emissionshandels verbessert werden, die eigentlich angemessene Lösung sei jedoch ein neues Instrument: Um die Entwicklungsländer in die Lage zu versetzen Maßnahmen in der Verkehrspolitik umzusetzen und Politiken und Projekte vor Ort zu fördern, sollte ein von den Industrieländern finanzierter Klimaschutzfonds unter dem UN-Klimaregime eingerichtet werden. In Strategien für eine kohlenstoffarme Entwicklung sind dabei die Politikinstrumente einer nachhaltigen Verkehrsentwicklung zu integrieren.