Cores in Dwarf Galaxies from Dark Matter with a Yukawa Potential

We show that cold dark matter particles interacting through a Yukawa potential could naturally explain the recently observed cores in dwarf galaxies without affecting the dynamics of objects with a much larger velocity dispersion, such as clusters of galaxies. The velocity dependence of the associated cross-section as well as the possible exothermic nature of the interaction alleviates earlier concerns about strongly interacting dark matter. Dark matter evaporation in low-mass objects might explain the observed deficit of satellite galaxies in the Milky Way halo and have important implications for the first galaxies and reionization.Comment: 6 pages, 2 figure

Use of risk adjustment in setting budgets and measuring performance in primary care I: how it works

Summary points: Primary care groups and general practices will be funded largely through capitation based formulas, and their performance will be monitored more closely. Current methods of funding primary care trusts and general practices, and of monitoring their performance, do not take into account differences in case mix. Risk adjustment methods have been developed in the United States to allow measurement ofcase mix and morbidity of primary care populations. Risk adjustment methods are now being used to set capitation rates for health services in the United States

The Golden Retriever Rule: Alaska’s Identity Privilege for Animal Adoption Agencies and for Adoptive Animal Owners

Sedan 1900-talets mitt har användandet av tegelkonstruktioner i bostadsbyggandet minskat kraftigt; materialet har under modernismen upplevts otidsenligt och byggnadssättet har ansetts ineffektivt. Trots att kanalmurstekniken, som är en byggteknik med bärande tegelkonstruktion och högt isoleringsvärde, togs fram på 1930-talet för att följa hårdare energihushållningskrav, har ändå lätta träregelkonstruktioner dominerat det svenska småhusbyggandet. Kraven på energihushållning har under åren ökat successivt och livscykelanalysen (LCA) har utvecklats. LCA är en metodik som analyserar produkters eller tjänsters klimatbelastning ur livscykelperspektiv. Svårigheter har dock funnits i att omsätta metodiken på större komponenter än enskilda material. Därför har europastandarder tagits fram som enkom tjänar till att systematisera livscykelanalyser av hela byggnader och de kommer att följas i denna studie. Syftet med examensarbetet är att jämföra hur ett typhus med tegel som stommaterial belastar miljön under produktion och drift i en livscykel satt till 100 år, jämfört med ett motsvarande trätyphus. Till tegelhusets nackdel talar den höga energiåtgången vid materialframställningen. Trä å sin sida löper stor risk för förkortad livscykel i och med riskerna för fuktskador. För att undersöka skillnaderna i trä- och tegelkonstruktioner har en typhusritning i kanalmurskonstruktion analyserats mot en motsvarande träkonstruktion, där byggnadstyperna har samma boarea och väggkonstruktionerna samma värmemotstånd. För att få fram husens skillnad energiåtgång under driftskedet har energibehovsberäkningar utförts för byggnaderna. Livscykelanalysen har utförts i programvaran Anavitor utifrån 3D-modeller med byggnadsinformation som matchas mot en materialdatabas med livscykeldata. Ur jämförelsen har resultat kunnat hämtas på vilken av konstruktionerna som belastar miljön minst över livscykeln, med avseende på klimatbelastning räknat i koldioxidekvivalenter. Resultat visar att ett tegelhus belastar miljön dubbelt så mycket som ett trähus i produktionsfasen medan tegelhuset är miljövänligare avseende underhåll och drift. Efter 100 år är skillnaden 7,3 ton koldioxidekvivalenter, till trähusets fördel. Enligt livscykelanalysen har byggnaderna, enligt de antaganden som gjorts, belastat miljön lika efter 168 år. Till tegelhusets fördel talar dess säkerhet gällande livslängd, beständighet, fuktsäkerhet och goda möjlighet till återbruk av stommaterialet.Since the mid-1900s has brick building marginalized; the material has in the modernist era been experienced as dated and the construction method considered inefficient. In the 1930s the canal wall technique were developed to meet the coming stringent energy requirements. Despite opportunities to meet modern building norms have yet lightweight timber structures dominated the Swedish construction sector concerning single-family houses since then. The requirements for energy conservation have increased over the years to an even greater degree, and Life Cycle Assessment (LCA) has been developed; a methodology that analyzes products from a life cycle perspective. There have been difficulties to put the methodology on larger components than individual materials. Therefore, European Standards have been developed that specifically serve to systematize Life Cycle Assessments of entire buildings, which will be followed in this study. The purpose of this study is to compare which impact a standard house with brick structure has a on the environment in a lifecycle set to 100 years, compared with a corresponding timber structure. To the disadvantage for a brick house speaks the high energy consumption in material production. Timber structures at their part are at high risk for shortened life cycle due to risk of moisture damage. To examine the differences in wood and brick structures has a standard house drawing in canal wall technique been analyzed against a corresponding wooden construction. The building types have the same floor area and the wall constructions have the same heat resistance. To receive the differences in energy use during the operational phase between the buildings has energy calculations been made. The life cycle analysis has been performed in the software Anavitor based on 3D models with building information that is matched against a database of materials life cycle data. The results from the comparison are measured in terms of carbon dioxide equivalents, and will show which construction type will make least impact on the environment. Results show that a brick house has doubled environmental impact compared to a wooden house in the production phase. The brick house is a better alternative concerning environmental impact during operational phase and maintenance. After 100 years, the difference is 7,3 tons of carbon dioxide equivalents to the advantage of the wooden house. According to the LCA and the assumptions made, the buildings have charged the environment equally after 168 years. To the advantage of the brick house speaks its longevity, durability, moisture resistance and good opportunity for reuse of the bricks

Income inequality : a summary of the Bank's 1998 Symposium

Income inequality has become an increasingly important public policy issue in industrialized countries in recent years. Although macroeconomic conditions have been favorable in many of these countries, the distribution of income within and across countries has remained uneven. In fact, in several countries, income inequality has risen. As a result, policymakers have become concerned that large segments of the population are not reaping the benefits of economic growth.> To gain a better understanding of these issues, the Federal Reserve Bank of Kansas City sponsored a symposium titled "Income Inequality: Issues and Policy Options" held at Jackson Hole, Wyoming, August 27-29, 1998. The symposium brought together a distinguished group of public officials, academics, and private-sector representatives. The discussion was far-ranging and insightful. As moderator Alice Rivlin noted toward the end of the conference, while there was a divergence of opinion in several areas, there was a consensus that "poverty, deprivation, and lack of opportunity are things that ought to be of great concern to us."> Weiner and Monto summarize the papers and commentary presented at the symposium. The first section reviews the changes in income inequality patterns over the past two decades. The second explores the reasons for these changes. Monetary policy links and the economic impact of distributional change are taken up in the following two sections. The final section considers policy options and summarizes the remarks of an overview panel.Income ; Income distribution

A characterization of Hermitian varieties as codewords

It is known that the Hermitian varieties are codewords in the code defined by the points and hyperplanes of the projective spaces $PG(r,q^2)$. In finite geometry, also quasi-Hermitian varieties are defined. These are sets of points of $PG(r,q^2)$ of the same size as a non-singular Hermitian variety of $PG(r,q^2)$, having the same intersection sizes with the hyperplanes of $PG(r,q^2)$. In the planar case, this reduces to the definition of a unital. A famous result of Blokhuis, Brouwer, and Wilbrink states that every unital in the code of the points and lines of $PG(2,q^2)$ is a Hermitian curve. We prove a similar result for the quasi-Hermitian varieties in $PG(3,q^2)$, $q=p^{h}$, as well as in $PG(r,q^2)$, $q=p$ prime, or $q=p^2$, $p$ prime, and $r\geq 4$

Transform-limited pulses are not optimal for resonant multiphoton transitions

Maximizing nonlinear light-matter interactions is a primary motive for compressing laser pulses to achieve ultrashort transform limited pulses. Here we show how, by appropriately shaping the pulses, resonant multiphoton transitions can be enhanced significantly beyond the level achieved by maximizing the pulse's peak intensity. We demonstrate the counterintuitive nature of this effect with an experiment in a resonant two-photon absorption, in which, by selectively removing certain spectral bands, the peak intensity of the pulse is reduced by a factor of 40, yet the absorption rate is doubled. Furthermore, by suitably designing the spectral phase of the pulse, we increase the absorption rate by a factor of 7.Comment: 4 pages, 3 figure