Initial development of soil structure and soil organic matter in an agriculturally managed chronosequence on recultivated loess

Soil structure and soil organic matter (SOM) are closely connected characteristics of a soil material. Their interactions affect various physical, chemical and biological soil properties like water holding capacity, carbon stabilization and microbial habitat. The intertwined development of soil structure and quality and quantity of SOM during soil formation are not clear until now. We used a chronosequence approach in the recultivated open-cast mining area near Cologne, Germany to elucidate the development of soil structure and soil organic matter during initial soil formation in a loess material. We selected six plots with different ages of agricultural management after recultivation (0, 1, 3, 6, 12, and 24 years after first seeding). In each plot 12 spatially independent locations were sampled with stainless steel cylinders (100 cm3) at three depths representing the topsoil (1-5 cm), the plough layer (16-20 cm), and the management-unaffected parent material (41-45 cm). All samples were analysed for bulk density, organic and inorganic carbon and nitrogen content, and aggregate size distribution. We evaluated the development of aggregation and soil organic matter stocks during this early phase of soil formation. This system is temporarily highly dynamic and shows different developments for bulk density, SOM and aggregate formation. In just one year bulk density increased to an average of 1.6 g/cm³ and remained stable for the next three years. After agricultural management with ploughing and cultivation from the 6 years, all sites showed bulk density decrease, which remained stable from topsoil to parent material after 12 years with average bulk density 1,5 g/cm3. Soil carbon content increased during the chronosequence and showed highest variability from 2,3 mgC/g to 18,7 mgC/g in the 3 years old field, which shows the beginning of the interaction between soil and biota, and carbon input

Experimentally exploring compressed sensing quantum tomography

In the light of the progress in quantum technologies, the task of verifying the correct functioning of processes and obtaining accurate tomographic information about quantum states becomes increasingly important. Compressed sensing, a machinery derived from the theory of signal processing, has emerged as a feasible tool to perform robust and significantly more resource-economical quantum state tomography for intermediate-sized quantum systems. In this work, we provide a comprehensive analysis of compressed sensing tomography in the regime in which tomographically complete data is available with reliable statistics from experimental observations of a multi-mode photonic architecture. Due to the fact that the data is known with high statistical significance, we are in a position to systematically explore the quality of reconstruction depending on the number of employed measurement settings, randomly selected from the complete set of data, and on different model assumptions. We present and test a complete prescription to perform efficient compressed sensing and are able to reliably use notions of model selection and cross-validation to account for experimental imperfections and finite counting statistics. Thus, we establish compressed sensing as an effective tool for quantum state tomography, specifically suited for photonic systems.Comment: 12 pages, 5 figure

Phytosulfokine-α Controls Hypocotyl Length and Cell Expansion in Arabidopsis thaliana through Phytosulfokine Receptor 1

The disulfated peptide growth factor phytosulfokine-α (PSK-α) is perceived by LRR receptor kinases. In this study, a role for PSK signaling through PSK receptor PSKR1 in Arabidopsis thaliana hypocotyl cell elongation is established. Hypocotyls of etiolated pskr1-2 and pskr1-3 seedlings, but not of pskr2-1 seedlings were shorter than wt due to reduced cell elongation. Treatment with PSK-α did not promote hypocotyl growth indicating that PSK levels were saturating. Tyrosylprotein sulfotransferase (TPST) is responsible for sulfation and hence activation of the PSK precursor. The tpst-1 mutant displayed shorter hypocotyls with shorter cells than wt. Treatment of tpst-1 seedlings with PSK-α partially restored elongation growth in a dose-dependent manner. Hypocotyl elongation was significantly enhanced in tpst-1 seedlings at nanomolar PSK-α concentrations. Cell expansion was studied in hypocotyl protoplasts. WT and pskr2-1 protoplasts expanded in the presence of PSK-α in a dose-dependent manner. By contrast, pskr1-2 and pskr1-3 protoplasts were unresponsive to PSK-α. Protoplast swelling in response to PSK-α was unaffected by ortho-vanadate, which inhibits the plasma membrane H+-ATPase. In maize (Zea mays L.), coleoptile protoplast expansion was similarly induced by PSK-α in a dose-dependent manner and was dependent on the presence of K+ in the media. In conclusion, PSK-α signaling of hypocotyl elongation and protoplast expansion occurs through PSKR1 and likely involves K+ uptake, but does not require extracellular acidification by the plasma membrane H+-ATPase

Magnetization in short-period mesoscopic electron systems

We calculate the magnetization of the two-dimensional electron gas in a short-period lateral superlattice, with the Coulomb interaction included in Hartree and Hartree-Fock approximations. We compare the results for a finite, mesoscopic system modulated by a periodic potential, with the results for the infinite periodic system. In addition to the expected strong exchange effects, the size of the system, the type and the strength of the lateral modulation leave their fingerprints on the magnetization.Comment: RevTeX4, 10 pages with 14 included postscript figures To be published in PRB. Replaced to repair figure

A global investigation of music listening practices: the influence of country latitude and seasons on music preferences

Background: Most research on correlates of music preference considers micro-level influences, such as personality and social positional levels (Rentfrow & Gosling, 2003; North & Hargreaves, 1996). However, it is important to consider macro-level influences, such as cultural norms and the effects of time and weather, as well. An interesting macro-level influence that is gaining research attention is the consideration of seasonal effects (Helmholz, et al., 2017; Krause & North, 2018; Park, et al., 2019). For example, Krause and North’s (2018, p. 89) research demonstrated that listeners preferred “arousing music for the warmer months, serene music for spring, and melancholy music for the cooler months”. Aims: The present study is a replication-extension study of Krause and North’s (2018) research. The aims of the present study included: 1. Replicating their findings drawing on a larger, global sample (including non-western countries and those with varying weather patterns and at different latitudes). 2. Exploring the extent that proxies for country and seasons (latitude) modulate response patterns. Method: A total of 2,140 participants from 47 countries across 4 continents completed an online questionnaire, which consisted of answering background questions and responding to a series of questions concerning the creation of music playlists. Importantly, as in Krause and North (2018), participants rated how well 24 adjectives (from three factors: Arousing, Serene, and Melancholy) describe preferred music for playlists (for each season); also, they indicated their favourite season, the season they were currently experiencing, and their country of residence. Results: Addressing the first aim, an exploratory factor analyses was conducted on the participants' adjective ratings to replicate that reported in Krause and North (2018). The results indicated that the proposed three factor solution on each of the four seasons from Autumn to Summer does not fit the data well using either the Comparitive Fit Index (0.79, 0.79, 0.81, 0.83) or Tucker Lewis Index (0.83, 0.83, 0.84, 0.86). We posit this model fit incongrunacy is due to initial model specification choices. Nevertheless, we continued our planned analyses and considered the impact of the participants’ country of residence. We tested the hypothesis that preferred arousal levels in music fluctuate according to the ecological environment: could countries with warmer summers prefer higher arousal music for warmer (summer) seasons, and countries with colder winters prefer lower arousal (melancholic) music for cooler (winter) seasons? Using mixed effects models with random effects for country, we found that countries with more extreme latitudes (warmer summers) preferred higher arousal music (b = -0.05, p = .036) for summer. However, no significant effect was observed for latitude and low arousal (melancholic) music (b = -0.03, p = .11). Conclusions: By examining the replicability of Krause and North's (2018) findings on a larger set of participants and countries, the present research contributes to the developing body of psychological research on music preference at the macro-level, focusing on contributing to our understanding of how broader factors play a role in music preference and everyday listening behaviours. Moreover, the findings will be considered relative to research concerning seasonal variations in other behaviours and experiences, which may have additional influences on areas such as financial behaviours, aggression, mental health, and mood

Intensive grazing leads to degradation and spatial homogenization of topsoils in two major steppetypes in Inner Mongolia , P .R . China

Introduction Intensive land use and especially overgrazing in semi‐arid grasslands results in degradation of steppe vegetation associated with changes in the amount ,composition ,and turnover of soil organic matter (SOM) . The concurrent degradation of soil structure and destruction of aggregation leads to enhanced soil erosion .The effectof intensive grazing on the amount and composition of SOM was assessed by comparison of grazed and ungrazed plots in Leymus chinensis and Stipa grandis dominated steppe types in Inner Mongolia ,Chin

Inspired and appreciated by the group: The social identity approach to creativity

This is the author accepted manuscript. The final version is available from Oxford University Press via the DOI in this recordThe processes of creative production and creativity recognition are both understood to be central to the dynamics of creativity. Nevertheless, they are generally seen by creativity researchers as theoretically unrelated. In contrast, social identity theorizing suggests a model of creativity in which groups play a role both in inspiring creative acts and in determining the reception they are given. More specifically, this approach argues that shared social identity (or lack of it) motivates individuals to rise to particular creative challenges and provides a basis for certain forms of creativity to be recognized (or disregarded). This chapter explicates the logic underlying the social identity approach and summarizes some of the key evidence that supports it

A Review of Target Mass Corrections

With recent advances in the precision of inclusive lepton--nuclear scattering experiments, it has become apparent that comparable improvements are needed in the accuracy of the theoretical analysis tools. In particular, when extracting parton distribution functions in the large-x region, it is crucial to correct the data for effects associated with the nonzero mass of the target. We present here a comprehensive review of these target mass corrections (TMC) to structure functions data, summarizing the relevant formulas for TMCs in electromagnetic and weak processes. We include a full analysis of both hadronic and partonic masses, and trace how these effects appear in the operator product expansion and the factorized parton model formalism, as well as their limitations when applied to data in the x->1 limit. We evaluate the numerical effects of TMCs on various structure functions, and compare fits to data with and without these corrections.Comment: 41 pages, 13 figures; minor updates to match published versio