1,696 research outputs found

    Resistance Breeding in Apple at Dresden-Pillnitz

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    Resistance breeding in apple has a long tradition at the Institute of Fruit Breeding now Julius Kuehn-institute in Dresden-Pillnitz. The breeding was aimed at the production of multiple resistance cultivars to allow a more sustainable and environmentally friendly production of apple. In the last decades a series of resistant cultivars (Re®-cultivars) bred in Dresden-Pillnitz has been released, ‘Recolor’ and ‘Rekarda’ in 2006. The main topic in the resistance breeding programme was scab resistance and the donor of scab resistance in most cultivars was Malus x floribunda 821. Due to the development of strains that are able to overcome resistance genes inherited by M. x floribunda 821 and due to the fact that single resistance genes can be broken easily, pyramiding of resistance genes is necessary. Besides scab, fire blight and powdery mildew are the main disease for which a pyramiding of genes is aspired in Pillnitz. Biotechnical approaches are necessary for the early detection of pyramided resistance genes in breeding clones. This paper will give an overview of the resistance breeding of apple in Pillnitz and the methods used

    Hypersexuality, gender, and sexual orientation: a large-scale psychometric survey study

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    Criteria for Hypersexual Disorder (HD) were proposed for consideration in the DSM-5 but ultimately excluded for a variety of reasons. Regardless, research continues to investigate hypersexual behavior (HB). The Hypersexual Behavior Inventory (HBI) is one of the most robust scales assessing HB, but further examination is needed to explore its psychometric properties among different groups. Therefore, the aim of the present study was to examine the generalizability of the HBI in a large, diverse, nonclinical sample (N = 18,034 participants; females = 6132; 34.0%; Mage = 33.6 years, SDage = 11.1) across both gender and sexual orientation. Measurement invariance testing was carried out to ensure gender- and sexual-orintation based comparisons were meaningful. Results demonstrated when both gender and sexual-orientation were considered (i.e., heterosexual males vs. LGBTQ males vs. heterosexual females vs. LGBTQ females), LGBTQ males had significantly higher latent means on the HBI factors. Results also demonstrated LGBTQ males had the highest scores on other possible indicators of hypersexuality (e.g., frequency of masturbation, number of sexual partners, or frequency of pornography viewing). These findings suggest LGBTQ males may be a group most at risk of engaging in hypersexual behavior and LGBTQ females are at a higher risk of engaging in hypersexual activities due to coping problems. Given the largescale nature of the study, the findings significantly contribute to the currently growing body of literature on hypersexuality

    On packing spanning arborescences with matroid constraint

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    Let D = (V + s, A) be a digraph with a designated root vertex S. Edmonds’ seminal result (see J. Edmonds [4]) implies that D has a packing of k spanning s-arborescences if and only if D has a packing of k (s, t)-paths for all t ∈ V, where a packing means arc-disjoint subgraphs. Let M be a matroid on the set of arcs leaving S. A packing of (s,t) -paths is called M-based if their arcs leaving S form a base of M while a packing of s-arborescences is called M -based if, for all t ∈ V, the packing of (s, t) -paths provided by the arborescences is M -based. Durand de Gevigney, Nguyen, and Szigeti proved in [3] that D has an M-based packing of s -arborescences if and only if D has an M-based packing of (s,t) -paths for all t ∈ V. Bérczi and Frank conjectured that this statement can be strengthened in the sense of Edmonds’ theorem such that each S -arborescence is required to be spanning. Specifically, they conjectured that D has an M -based packing of spanning S -arborescences if and only if D has an M -based packing of (s,t) -paths for all t ∈ V. In this paper we disprove this conjecture in its general form and we prove that the corresponding decision problem is NP-complete. We also prove that the conjecture holds for several fundamental classes of matroids, such as graphic matroids and transversal matroids. For all the results presented in this paper, the undirected counterpart also holds

    An empirical study on the motivations underlying augmented reality games: the case of Pokémon Go during and after Pokémon fever

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    In 2016, Pokémon Go became the most popular game in the history of smartphone games and was among the first games to feature geo-located augmented reality (AR) elements. The goal of the present research was to obtain a deeper understanding concerning the motivations underlying Pokémon Go use and to create a measure that assesses these motivations. By extending the framework of the Motives for Online Gaming Questionnaire, three new factors – Outdoor Activity, Nostalgia, and Boredom – were added based on the findings of qualitative analysis, and which led to the creation of the Motives for Online Gaming Questionnaire - Pokémon Go extension (MOGQ-PG). Confirmatory factor analysis was carried out on a sample of Pokémon Go players (N = 621). Results demonstrated that the final 37-item, first-order, 10-factor model had appropriate factor structure and internal consistency. A second follow-up study on Pokémon Go players (N = 510) examined associations between gaming motivations, problematic use, and impulsivity. Results demonstrated that impulsivity was not related to the MOGQ-PG motives. Results also showed that competition and fantasy motivations predicted problematic gaming behavior. The present research is the first empirical contribution to the assessment and understanding of the motivational background of playing AR games such as Pokémon Go
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