192 research outputs found
The Isolated Peasant. Long-term Growth in Demand and Spatial Patterns of Agricultural Supply in Southern Sweden, 1702-1857
Previous research has found clear spatial patterns of agricultural supply, both in pre-industrial Europe (Grantham 1978; Grantham 1989; Kopsidis 2009) and in the less developed countries of today (Benziger 1996; Stifel & Minten 2008). The spatial structure of farming intensity is mainly attributed to the declining net-returns with the distance from the market. This paper examines the impact of distance on agricultural productivity and whether the long-term growth in demand had a diminishing impact on the spatial variation in farming intensity. The analysis is carried out by using a database on estimates of agricultural production on the micro-level together with additional information on distance from a map from the 19th century for about 2200 farm households in the province of Scania in southern Sweden during the period 1702-1857. The effect of distance on agricultural production is studied with a general least square regression (GLS) for the time periods 1702-1775, 1776-1825 and 1826-1857. The results demonstrate a distinct spatial variation in farming intensity in southern Sweden. Further, the findings also show that the spatial patterns of agricultural supply even increased over time, despite a considerable growth in demand. Overall, the results indicate that increasing demand in itself was not a sufficient pre-condition for reducing the spatial variation in farming intensity
Hybrid Microwave-Cavity Heat Engine
We propose and analyze the use of hybrid microwave cavities as quantum heat
engines. A possible realization consists of two macroscopically separated
quantum dot conductors coupled capacitively to the fundamental mode of a
microwave cavity. We demonstrate that an electrical current can be induced in
one conductor through cavity-mediated processes by heating up the other
conductor. The heat engine can reach Carnot efficiency with optimal conversion
of heat to work. When the system delivers the maximum power, the efficiency can
be a large fraction of the Carnot efficiency. The heat engine functions even
with moderate electronic relaxation and dephasing in the quantum dots. We
provide detailed estimates for the electrical current and output power using
realistic parameters.Comment: 5 pages, 3 figures, final version as published in Phys. Rev. Let
Kom nÀrmre!
Det finns mÀngder av olika typer av studier som visar pÄ de positiva effekterna som vistelsen i naturen har pÄ vÄrt vÀlmÄende. Det hjÀlper oss bÄde psykiskt och fysiskt genom att till exempel ge oss ÄterhÀmtning, en minskad kÀnsla av stress och miljöer för fysisk aktivitet. Trots detta minskar kontakten mellan mÀnniska och natur som en konsekvens av en rad faktorer. För vissa kan naturen kÀnnas obehaglig i och med en ovana och brist pÄ kunskap. Andra kan ha svÄrt att ta sig ut till naturomrÄden rent fysiskt, pÄ grund av till exempel rörelsemÀssiga funktionsnedsÀttningar. Med tanke pÄ den stora tillgÄngen pÄ fina naturomrÄden vi har i Sverige gÄr mÄnga miste om alla de möjliga fördelarna som de skulle kunna fÄ om de lyckades ta sig ut i naturen mer. Dessutom har en ökad naturvistelse och naturkontakt pÄ lÀngre sikt en positiv inverkan pÄ mÀnniskors miljömedvetenhet och naturomsorg, nÄgot som har betydelse för den hÄllbarhetsomstÀllning vi stÄr inför.
Det hÀr examensarbetet syftar till att undersöka hur olika typer av landskapstillÀgg kan bidra till att locka ut fler till naturomrÄden och dÀrmed bidra till en ökad naturkontakt och en frÀmjad folkhÀlsa. Det har undersökts genom studerandet av olika typer av litteratur, samtal med olika personer med en yrkesmÀssig eller ideell koppling till Àmnet och genom studerandet av ett par olika referensprojekt. Resultatet av detta har sammanstÀllts i arbetets Kunskapsbas och kan kort sammanfattas med fem punkter: utveckling av entréomrÄden, tillgÀngliggörande, en ökad orienterbarhet, fler bekvÀmligheter och skapandet av mÄlpunkter genom ökade möjligheter till aktiviteter. Ett mer konkretiserat förslag pÄ hur dessa tillÀgg kan omsÀttas pÄ en faktiskt plats presenteras senare i arbetet. Det platsspecifika förslaget utgÄr frÄn en del av OrlÄngens naturreservat i Huddinge kommun och inkluderar en platsanalys och en utvecklingsplan med förslag pÄ ÄtgÀrder.
Det finns ett antal ÄtgÀrder som skulle kunna appliceras pÄ det valda studieomrÄdet kopplat till de fem sammanfattande punkterna. För att nÀmna nÄgra exempel gÀller det dels utveckling av omrÄdets entrépunkt och en förbÀttring av befintliga parkeringsplatser. Dels handlar det om en utveckling av befintligt skyltsystem med tydligare vÀganvisningar och fler informationsskyltar. Ett fÄgeltorn och upprÀttandet av en ny upplevelsestig skulle Àven kunna vara sÀtt att locka fler till platsen och nÀrmare naturen.
I diskussionen tas olika aspekter upp med koppling till utveckling av naturomrĂ„den och mĂ„let att nĂ„ fler besökare. Ăven om landskapstillĂ€gg kan ha en betydande roll för att locka ut fler i naturen sĂ„ kan det istĂ€llet i mĂ„nga fall vara avgörande med anordnandet av faktiska aktiviteter för att ovana grupper faktiskt ska ta sig ut och kĂ€nna sig bekvĂ€ma med det. En utveckling av omrĂ„det som mĂ„lpunkt Ă€r ocksĂ„ beroende av en viss nivĂ„ av kommunikation för att kunna nĂ„ ut till en bred skara. NĂ€mnas bör Ă€ven betydelsen av personliga preferenser nĂ€r det kommer till upplevelsen av naturomrĂ„den. Olika Ă„tgĂ€rder gynnar olika grupper av mĂ€nniskor, dĂ€r vissa föredrar de miljöerna som Ă€r mindre tillrĂ€ttalagda. För att nĂ„ de som annars inte tar sig ut, kan olika typer av landskapstillĂ€gg dock vara av större betydelse.There is plenty of scientific evidence on the positive health benefits of spending time outside in nature. It helps to improve both our mental and physical health through for instance restoration, stress reduction and environments for physical activities. Yet, the contact between human and nature is reducing as a consequence of various factors. Some people might feel a sense of discomfort being in nature due to a lack of knowledge and unfamiliarity with more natural settings. Considering the large and many nature areas we have in Sweden, many people miss out on all the possible positive wellbeing benefits they could get if they would use it more. In addition, an increased time spent in nature could have a positive impact on peopleâs care for nature, and environmentally responsible behaviour, which is of great importance in the transition towards a more sustainable society.
The aim of this paper is to get an understanding of how different types of additions in the landscape can contribute to more people getting out in nature, and thereby increase peopleâs both wellbeing and contact with nature. The study is based on different types of literature, interviews with people with a professional connection to the subject, and through observations of different existing examples. The result of this can be summarised in five categories: development of entrances, improved accessibility, increased orientability, more amenities and creation of destination points through increased possibilities for activities. A more concrete proposal of how these kinds of additions can be implemented is presented in the case study chapter. The case study is based on a part of OrlĂ„ngenâs nature reserve in Huddinge municipality and involves a site analysis and a plan of development with more specific suggestions of development.
Several measures can be implemented on the site based on the five categories. To mention some examples, these include an improvement of the areaâs entry points with adjacent parking spaces. It also includes a development of the existing sign system with better directional and informational signs. A bird tower or a new experience path are also suggested to attract more people and increase their contact with nature.
Even if landscape additions can play a significant role to attract more people to visit nature, it can in many cases instead be more important with arrangements of actual events and activities to address the groups that are least familiar with nature. A development of the area as a stronger destination point is also dependent on some kind of communication to reach out to a broader public. Worth mentioning is also the significance of personal preferences when it comes to the experience of nature. Different measures favour different groups of people, and some might prefer the more naturalistic environments without additions. However, landscape additions can be of greater value to address the ones that visit nature areas more seldom
Plant selection for rain gardens : a design for a rain garden in Rosendal, Uppsala
En av de funktioner grönytor fyller Àr att ta hand om och infiltrera vatten. NÀr stÀder i vÀrlden vÀxer, ökar mÀngden hÄrdgjorda ytor. Det innebÀr att avrinningen blir större och dÀrmed Àven mÀngden dagvatten som behöver tas omhand. PÄ grund av klimatförÀndringarna förvÀntas dessutom nederbörden stundtals bli mer intensiv. RegnbÀddar har tagits fram som en metod för att hantera vattenflöden och minska belastningen pÄ stÀders dagvattenledningssystem. Genom att anlÀgga nedsÀnkta vÀxtbÀddar i anslutning till hÄrdgjorda ytor kan dagvatten ledas in till bÀdden dÀr det kan fördröjas och sedan antingen infiltrera ner i marken eller ledas vidare. Med tanke pÄ bÀddarnas goda infiltrerande förmÄga skapas sÀrskilda vÀxtförutsÀttningar. VÀxterna ska klara lÀngre perioder av torka samtidigt som att vattnet i bÀdden stundtals kan komma att bli stÄende. I denna rapport presenteras listor med vÀxter som kan lÀmpa sig för gestaltning av regnbÀddar i Uppsalatrakten. För att visa pÄ hur vÀxtlistorna kan tillÀmpas presenteras ocksÄ en gestaltning för en regnbÀdd i Rosendal, Uppsala. Gestaltningen utgick bland annat frÄn att den skulle vara praktfull med en variation av arter, ha Ärstidsvariationer sÄsom vinterstÄndare och att den skulle ta hÀnsyn till omgivningen. Detta genom att verka avskiljande mellan gata och trottoar samtidigt som att sikten mellan trafikanter inte ska hindras alltför mycket. Det finns mÄnga faktorer som pÄverkar regnbÀdden sÄsom stÄndort, vilken varierar mycket frÄn plats till plats. DÀrför finns ingen garanti pÄ att vÀxterna kommer att fungera bra i bÀdden. Förslaget behöver testas i praktiken för att faktiskt se om det Àr lÀmpligt.Green infrastructure contributes to many ecosystem services. One of them is to take care of, and infiltrate water. When cities are growing, the amount of impermeable surfaces increase. That leads to an increasing amount of surface water that needs to be taken care of. In addition, rainfalls are expected to get more intense as a consequence of climate change. Rain gardens have been developed as a method to cope with these higher run-offs. Through depressed rain gardens next to impermeable surfaces, runoff can be led directly to the installation where it can be delayed and subsequently either infiltrate through the ground or be led onwards. The high infiltration capacity of the rain gardens makes the growth environment very special. The plants are required to cope with long periods of drought meanwhile the water in the plantation during shorter periods can be standing. It can therefore be a challenge to find plants who can manage these conditions. This report presents lists of plants that can be suitable for designing rain gardens in the region of Uppsala. A planting design is also presented on a rain garden in Rosendal, Uppsala, to exemplify how the lists can be applied in reality. Principles for the design was for example to make the plantation grand with various species, a seasonal variation and with considerations the surroundings. Since there are many factors that affect the environment in the rain garden, the planting design has to be implemented and tested practically to see how it works in reality
Pump-probe scheme for electron-photon dynamics in hybrid conductor-cavity systems
Recent experiments on nanoscale conductors coupled to microwave cavities put
in prospect transport investigations of electron-photon interplay in the deep
quantum regime. Here we propose a pump-probe scheme to investigate the
transient dynamics of individual electron-photon excitations in a double
quantum dot-cavity system. Excitations pumped into the system decay via charge
tunneling at the double dot, probed in real time. We investigate theoretically
the short-time charge transfer statistics at the dot, for periodic pumping, and
show that this gives access to vacuum Rabi oscillations as well as excitation
dynamics in the presence of double dot dephasing and relaxation.Comment: 5 Pages, 5 figure
Microwave quantum optics and electron transport through a metallic dot strongly coupled to a transmission line cavity
We investigate theoretically the properties of the photon state and the
electronic transport in a system consisting of a metallic quantum dot strongly
coupled to a superconducting microwave transmission line cavity. Within the
framework of circuit quantum electrodynamics we derive a Hamiltonian for
arbitrary strong capacitive coupling between the dot and the cavity. The
dynamics of the system is described by a quantum master equation, accounting
for the electronic transport as well as the coherent, non-equilibrium
properties of the photon state. The photon state is investigated, focusing on,
for a single active mode, signatures of microwave polaron formation and the
effects of a non-equilibrium photon distribution. For two active photon modes,
intra mode conversion and polaron coherences are investigated. For the
electronic transport, electrical current and noise through the dot and the
influence of the photon state on the transport properties are at the focus. We
identify clear transport signatures due to the non-equilibrium photon
population, in particular the emergence of superpoissonian shot-noise at
ultrastrong dot-cavity couplings.Comment: 19 pages, 10 figure
Production of Secretory Leucocyte Protease Inhibitor (SLPI) in Human Pancreatic ÎČ-Cells
Liver resection for HER2-enriched breast cancer metastasis: case report and review of the literature
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