Intensive agriculture reduces soil biodiversity across Europe

Soil biodiversity plays a key role in regulating the processes that underpin the delivery of ecosystem goods and services in terrestrial ecosystems. Agricultural intensification is known to change the diversity of individual groups of soil biota, but less is known about how intensification affects biodiversity of the soil food web as a whole, and whether or not these effects may be generalized across regions. We examined biodiversity in soil food webs from grasslands, extensive, and intensive rotations in four agricultural regions across Europe: in Sweden, the UK, the Czech Republic and Greece. Effects of land-use intensity were quantified based on structure and diversity among functional groups in the soil food web, as well as on community-weighted mean body mass of soil fauna. We also elucidate land-use intensity effects on diversity of taxonomic units within taxonomic groups of soil fauna. We found that between regions soil food web diversity measures were variable, but that increasing land-use intensity caused highly consistent responses. In particular, land-use intensification reduced the complexity in the soil food webs, as well as the community-weighted mean body mass of soil fauna. In all regions across Europe, species richness of earthworms, Collembolans, and oribatid mites was negatively affected by increased land-use intensity. The taxonomic distinctness, which is a measure of taxonomic relatedness of species in a community that is independent of species richness, was also reduced by land-use intensification. We conclude that intensive agriculture reduces soil biodiversity, making soil food webs less diverse and composed of smaller bodied organisms. Land-use intensification results in fewer functional groups of soil biota with fewer and taxonomically more closely related species. We discuss how these changes in soil biodiversity due to land-use intensification may threaten the functioning of soil in agricultural production systems.

Biodiversity and resilience of ecosystem functions

Accelerating rates of environmental change and the continued loss of global biodiversity threaten functions and services delivered by ecosystems. Much ecosystem monitoring and management is focused on the provision of ecosystem functions and services under current environmental conditions, yet this could lead to inappropriate management guidance and undervaluation of the importance of biodiversity. The maintenance of ecosystem functions and services under substantial predicted future environmental change (i.e., their ‘resilience’) is crucial. Here we identify a range of mechanisms underpinning the resilience of ecosystem functions across three ecological scales. Although potentially less important in the short term, biodiversity, encompassing variation from within species to across landscapes, may be crucial for the longer-term resilience of ecosystem functions and the services that they underpin.

The combined influences of westerly phase of the quasi biennial oscillation and 11-year solar maximum conditions on the Northern Hemisphere extratropical winter circulation

The combined influences of the westerly phase of the quasi-biennial oscillation (QBO-W) and solar maximum (Smax) conditions on the Northern Hemisphere extratropical winter circulation are investigated using reanalysis data and Center for Climate System Research/National Institute for Environmental Studies chemistry climate model (CCM) simulations. The composite analysis for the reanalysis data indicates strengthened polar vortex in December followed by weakened polar vortex in February–March for QBO-W during Smax (QBO-W/Smax) conditions. This relationship need not be specific to QBO-W/Smax conditions but may just require strengthened vortex in December, which is more likely under QBO-W/Smax. Both the reanalysis data and CCM simulations suggest that dynamical processes of planetary wave propagation and meridional circulation related to QBO-W around polar vortex in December are similar in character to those related to Smax; furthermore, both processes may work in concert to maintain stronger vortex during QBO-W/Smax. In the reanalysis data, the strengthened polar vortex in December is associated with the development of north–south dipole tropospheric anomaly in the Atlantic sector similar to the North Atlantic oscillation (NAO) during December–January. The structure of the north–south dipole anomaly has zonal wavenumber 1 (WN1) component, where the longitude of anomalous ridge overlaps with that of climatological ridge in the North Atlantic in January. This implies amplification of the WN1 wave and results in the enhancement of the upward WN1 propagation from troposphere into stratosphere in January, leading to the weakened polar vortex in February–March. Although WN2 waves do not play a direct role in forcing the stratospheric vortex evolution, their tropospheric response to QBO-W/Smax conditions appears to be related to the maintenance of the NAO-like anomaly in the high-latitude troposphere in January. These results may provide a possible explanation for the mechanisms underlying the seasonal evolution of wintertime polar vortex anomalies during QBO-W/Smax conditions and the role of troposphere in this evolution.

The medieval climate anomaly and Byzantium: a review of the evidence on climatic fluctuations, economic performance and societal change

At the beginning of the Medieval Climate Anomaly, in the ninth and tenth century, the medieval eastern Roman empire, more usually known as Byzantium, was recovering from its early medieval crisis and experiencing favourable climatic conditions for the agricultural and demographic growth. Although in the Balkans and Anatolia such favourable climate conditions were prevalent during the eleventh century, parts of the imperial territories were facing significant challenges as a result of external political/military pressure. The apogee of medieval Byzantine socio-economic development, around AD 1150, coincides with a period of adverse climatic conditions for its economy, so it becomes obvious that the winter dryness and high climate variability at this time did not hinder Byzantine society and economy from achieving that level of expansion. Soon after this peak, towards the end of the twelfth century, the populations of the Byzantine world were experiencing unusual climatic conditions with marked dryness and cooler phases. The weakened Byzantine socio-political system must have contributed to the events leading to the fall of Constantinople in AD 1204 and the sack of the city. The final collapse of the Byzantine political control over western Anatolia took place half century later, thus contemporaneous with the strong cooling effect after a tropical volcanic eruption in AD 1257. We suggest that, regardless of a range of other influential factors, climate change was also an important contributing factor to the socio-economic changes that took place in Byzantium during the Medieval Climate Anomaly. Crucially, therefore, while the relatively sophisticated and complex Byzantine society was certainly influenced by climatic conditions, and while it nevertheless displayed a significant degree of resilience, external pressures as well as tensions within the Byzantine society more broadly contributed to an increasing vulnerability in respect of climate impacts. Our interdisciplinary analysis is based on all available sources of information on the climate and society of Byzantium, that is textual (documentary), archaeological, environmental, climate and climate model-based evidence about the nature and extent of climate variability in the eastern Mediterranean. The key challenge was, therefore, to assess the relative influence to be ascribed to climate variability and change on the one hand, and on the other to the anthropogenic factors in the evolution of Byzantine state and society (such as invasions, changes in international or regional market demand and patterns of production and consumption, etc.). The focus of this interdisciplinary

Cosmic shear requirements on the wavelength dependence of telescope point spread functions

Cosmic shear requires high precision measurement of galaxy shapes in the presence of the observational point spread function (PSF) that smears out the image. The PSF must therefore be known for each galaxy to a high accuracy. However, for several reasons, the PSF is usually wavelength dependent; therefore, the differences between the spectral energy distribution of the observed objects introduce further complexity. In this paper, we investigate the effect of the wavelength dependence of the PSF, focusing on instruments in which the PSF size is dominated by the diffraction limit of the telescope and which use broad-band filters for shape measurement. We first calculate biases on cosmological parameter estimation from cosmic shear when the stellar PSF is used uncorrected. Using realistic galaxy and star spectral energy distributions and populations and a simple three-component circular PSF, we find that the colour dependence must be taken into account for the next generation of telescopes. We then consider two different methods for removing the effect: (i) the use of stars of the same colour as the galaxies and (ii) estimation of the galaxy spectral energy distribution using multiple colours and using a telescope model for the PSF. We find that both of these methods correct the effect to levels below the tolerances required for per cent level measurements of dark energy parameters. Comparison of the two methods favours the template-fitting method because its efficiency is less dependent on galaxy redshift than the broad-band colour method and takes full advantage of deeper photometry.

An accelerating cosmology without dark energy

The negative pressure accompanying gravitationally-induced particle creation can lead to a cold dark matter (CDM) dominated, accelerating Universe (Lima et al. 1996 [1]) without requiring the presence of dark energy or a cosmological constant. In a recent study, Lima et al. 2008 [2] (LSS) demonstrated that particle creation driven cosmological models are capable of accounting for the SNIa observations [3] of the recent transition from a decelerating to an accelerating Universe, without the need for Dark Energy. Here we consider a class of such models where the particle creation rate is assumed to be of the form Gamma = beta H + gamma H(0), where H is the Hubble parameter and H(0) is its present value. The evolution of such models is tested at low redshift by the latest SNe Ia data provided by the Union compilation [4] and at high redshift using the value of z(eq), the redshift of the epoch of matter - radiation equality, inferred from the WMAP constraints on the early Integrated Sachs-Wolfe (ISW) effect [5]. Since the contributions of baryons and radiation were ignored in the work of LSS, we include them in our study of this class of models. The parameters of these more realistic models with continuous creation of CDM are constrained at widely-separated epochs (z(eq) approximate to 3000 and z approximate to 0) in the evolution of the Universe. The comparison of the parameter values, {beta, gamma}, determined at these different epochs reveals a tension between the values favored by the high redshift CMB constraint on z(eq) from the ISW and those which follow from the low redshift SNIa data, posing a potential challenge to this class of models. While for beta = 0 this conflict is only at less than or similar to 2 sigma, it worsens as beta increases from zero.

Border trees of complex networks

The comprehensive characterization of the structure of complex networks is essential to understand the dynamical processes which guide their evolution. The discovery of the scale-free distribution and the small-world properties of real networks were fundamental to stimulate more realistic models and to understand important dynamical processes related to network growth. However, the properties of the network borders (nodes with degree equal to 1), one of its most fragile parts, remained little investigated and understood. The border nodes may be involved in the evolution of structures such as geographical networks. Here we analyze the border trees of complex networks, which are defined as the subgraphs without cycles connected to the remainder of the network (containing cycles) and terminating into border nodes. In addition to describing an algorithm for identification of such tree subgraphs, we also consider how their topological properties can be quantified in terms of their depth and number of leaves. We investigate the properties of border trees for several theoretical models as well as real-world networks. Among the obtained results, we found that more than half of the nodes of some real-world networks belong to the border trees. A power-law with cut-off was observed for the distribution of the depth and number of leaves of the border trees. An analysis of the local role of the nodes in the border trees was also performed.

Elitidrottsproblem? : En kvalitativ studie om elitidrottares karriäravslutning

This paper used a qualitative technique from a social scientific perspective, a model based on Hewitt and his theory of the self-concept. The purpose of this study was to investigate why some elite athletes experience troublesome periods after their career ending. Interviews were performed with five elite athletes with varying experiences after career ending. The length of the elite athlete careers vary between 7 to 17 years. Two groups were made based upon experiences after career ending. Group 1 had experienced problems, for example suicide tendency, and group 2 had not. The result shows that a troublesome period can come up independently of career ending. The self-concept was investigated during the career and further different kind of variables which could affect the self as training and competition, social relations both before and after termination from sport. Result indicates that an individual in group 2 who has a high complexity in the self-concept based upon significant others outside the elite sport during the career copes with the new situation after career ending much better than group 1 who have not. To build up the self based only upon significant others in the elite sport seems to give expression in a strengthen self. Intensity in training and competition did not have a connection with a troublesome period after retirement from sport but it could prevent establishing contact with others outside the elite sport and reduce a high complexity in the self-concept. The result further shows that elite athletes who practise an individual sport trains in to a greater extent than elite athletes in a seasonal sport. Result also shows that practising a sport with one day off a week, contributes to better opportunities for developing a higher complexity in the self-concept. Suspicions has also rouse that practising an elite sport on the highest level can lead to extensive focusing that further leads to social isolation from individuals outside elite sport. To build up the self upon significant others outside elite sport during the career and keep in touch with significant others from elite sport after the career seems to be the key to avoid problems after the career ending. Suggestions about further investigations are made to see if medial exposure and status can affect the self.

L’évolution du français par rapport à l’histoire et en comparaison avec celle du suédois

Une langue est comme un être vivant. Elle porte les traces des avis, des sentiments, de la joie et des déceptions de nos ancêtres. En même temps elle reflète les toutes tous derniers modes de vie et la manière de penser et d’agir dans la vie quotidienne. Ce sont sa grammaire, ses mots, ses proverbes et ses citations qui en témoignent. Ses sons soulignés par l’intonation et la prosodie nous laissent presque deviner l’esprit de vitalité, de mélancolie ou d’élégance de la langue et de ces locuteurs. Mais est-ce qu’il est possible de trouver aussi les traces des événements historiques et sociaux dans l’évolution d’une langue? Cette question est centrale dans ce mémoire qui suit l’évolution du français à partir du latin parlé dans l’Antiquité et en comparaison avec celle d’autres langues notamment celle du suédois.

Passive MVC och MVVM designmönster i Android : En jämförelse av kodkomplexitet mellan Passive MVC och MVVM

Det mobila operativsystemet Android är idag ett ganska dominerande operativsystem på den mobila marknaden dels på grund av sin öppenhet men också på grund av att tillgängligheten är stor i och med både billiga och dyra telefoner finns att tillgå. Men idag har Android inget fördefinierat designmönster vilket leder till att varje utvecklare får bestämma själv vad som ska användas, vilket ibland kan leda till onödigt komplex kod i applikationerna som sen blir svårtestad och svårhanterlig. Detta arbete ämnar jämföra två designmönster, Passive Model View Controller (PMVC) och Model View View-Model (MVVM), för att se vilket designmönster som blir minst komplext med hjälp av att räkna fram mätvärden med hjälp av Cyclomatic Complexity Number (CCN). Studien är gjord utifrån arbetssättet Design & Creation och ämnar bidra med: kunskap om vilket mönster man bör välja, samt om CCN kan peka ut vilka delar i en applikation som kommer att ta mer eller mindre lång tid att testa. Under studiens gång tog vi även fram skillnader på om man anväder sig av den så kallade Single Responsibilyt Principle (SRP) eller inte. Detta för att se om separerade vyer gör någon skillnad i applikationernas komplexitet. I slutändan så visar studien på att komplexiteten i små applikationer är väldigt likvärdig, men att man även på små applikationer kan se skillnad på hur komplex koden är men också att kodkomplexitet på metodnivå kan ge riktlinjer för testfall.