Bedeutung selbst begrünter Brachstreifen für die Segetalflora von Sandäckern im Ökologischen Landbau

In a one-year study in Northern Germany, we analyzed the effects of unsown fallow strips and landscape heterogeneity on the segetal flora of organically managed sandy fields. Diversity of plants was higher in two/three-year-old fallow strips compared to reference sites tilled with winter rye. Concerning endangered species, this effect was more pronounced in fields that were in a small-scale than in a homogenous landscape, as the latter possibly featured less colonization potential

Weed seed predation in organic and conventional cereal fields

Granivores can consume a large proportion of newly produced weed seeds in crop fields each year. If substantial, granivores can help to exhaust the seed bank and thus contribute to long-term weed control. In northern Germany, however, annual seed losses tend to be smaller and granivore density lower than elsewhere. To investigate if high land-use intensity could be involved, seed predation rates were measured using Lolium multiflorum Lam. as a model seed in three organic and three conventional cereal fields located close to each other. In addition, seed predation was measured at different distances from the field edge and exclosure cages were used to determine the relative contributions of vertebrates and invertebrates to seed consumption.As expected for cereal crops, seed predation rates increased from early spring to early summer and then decreased again. Seed predation by invertebrates was comparable to that in other studies, but seed predation by vertebrates, mainly rodents, was much lower, suggesting that low seed predation rates in northern Germany may have been caused by lower mouse activity, concurring with low mouse density. Results with regard to the effect of distance to the field edge were variable and difficult to interpret. Observed responses may be linked to predator identity, with rodents foraging preferentially near field edges, and invertebrates away from field edges or indifferently. Farming system (organic vs. conventional) had little or no effect on seed predation rates.Reasons for the low density of seed predators and low seed predation rates observed are unknown, but it is likely that some unidentified detrimental factor is involved in the organic fields or the impoverished landscape as a whole. Keywords: Biological weed control, carabid beetles, distance to field edge, farming system, miceSamenfraß in Getreide auf ökologisch und konventionell bewirtschafteten FeldernSamenfraß durch Granivoren kann zu hohem Verlust neuproduzierter Unkrautsamen führen. Falls dies in beträchtlichem Maße geschieht, verringert Samenfraß den Samenbankeintrag substantiell und trägt damit zur langfristigen Unkrautregulierung bei. In Norddeutschland scheinen die jährlichen Samenverluste und die Prädatorendichten jedoch geringer zu sein als anderenorts. Um zu untersuchen, ob die hohe Landnutzungsintensität hierfür ursächlich sein könnte, wurden Samenfraßraten unter Nutzung von Lolium multiflorum Lam. als Modellsamen auf drei ökologisch und drei konventionell bewirtschafteten, räumlich nah beieinander liegenden Getreidefeldern ermittelt. Darüber hinaus wurde der Samenfraß in unterschiedlichen Abständen zum Feldrand erfasst. Ausschlusskäfige wurden genutzt, um zwischen dem Samenfraß durch Vertebraten und Invertebraten unterscheiden zu können.Wie im Getreideanbau zu erwarten, stieg die Samenfraßrate vom Frühling bis zum Sommer an und sank dann wieder. Der Samenfraß durch Invertebraten war vergleichbar mit dem anderer Studien. Die Samenprädation durch Vertebraten, hier hauptsächlich Nagetiere, war hingegen deutlich niedriger, ebenso die erfasste Aktivitätsdichte. Die zu beobachtenden niedrigen Samenfraßraten in Norddeutschland könnten demnach durch niedrige Vertebraten-Aktivitätsdichten beeinflusst sein. Die Ergebnisse bezüglich der Wirkung des Feldrandabstands waren unterschiedlich und schwer zu interpretieren. Die beobachteten Unterschiede könnten mit der Prädatorenart zusammenhängen, da Nagetiere bei der Nahrungssuche Feldränder und Invertebraten mehr die Feldmitte bevorzugen oder überall zu finden sind. Die Bewirtschaftungsform (ökologisch vs. konventionell) hatte wenig oder keinen Einfluss auf die Samenfraßraten.Die Gründe für die beobachteten geringen Samenprädatorendichten und Samenfraßraten sind unbekannt,aber es ist wahrscheinlich, das gegenteilig wirkende Einflüsse auf den ökologischen Feldern oder die verarmte Landschaft als Ganzes als Ursache in Frage kommen.Stichwörter: Abstand zum Feldrand, Bewirtschaftungsformen, Biologische Unkrautbekämpfung, Laufkäfer, Mäus

A repeat protein links Rubisco to form the eukaryotic carbon-concentrating organelle.

Biological carbon fixation is a key step in the global carbon cycle that regulates the atmosphere's composition while producing the food we eat and the fuels we burn. Approximately one-third of global carbon fixation occurs in an overlooked algal organelle called the pyrenoid. The pyrenoid contains the CO2-fixing enzyme Rubisco and enhances carbon fixation by supplying Rubisco with a high concentration of CO2 Since the discovery of the pyrenoid more that 130 y ago, the molecular structure and biogenesis of this ecologically fundamental organelle have remained enigmatic. Here we use the model green alga Chlamydomonas reinhardtii to discover that a low-complexity repeat protein, Essential Pyrenoid Component 1 (EPYC1), links Rubisco to form the pyrenoid. We find that EPYC1 is of comparable abundance to Rubisco and colocalizes with Rubisco throughout the pyrenoid. We show that EPYC1 is essential for normal pyrenoid size, number, morphology, Rubisco content, and efficient carbon fixation at low CO2 We explain the central role of EPYC1 in pyrenoid biogenesis by the finding that EPYC1 binds Rubisco to form the pyrenoid matrix. We propose two models in which EPYC1's four repeats could produce the observed lattice arrangement of Rubisco in the Chlamydomonas pyrenoid. Our results suggest a surprisingly simple molecular mechanism for how Rubisco can be packaged to form the pyrenoid matrix, potentially explaining how Rubisco packaging into a pyrenoid could have evolved across a broad range of photosynthetic eukaryotes through convergent evolution. In addition, our findings represent a key step toward engineering a pyrenoid into crops to enhance their carbon fixation efficiency

CARMA1- and MyD88-dependent activation of Jun/ATF-type AP-1 complexes is a hallmark of ABC diffuse large B-cell lymphomas.

A hallmark of the diffuse large B-cell lymphoma (DLBCL) of the activated B-cell (ABC) type, a molecular subtype characterized by adverse outcome, is constitutive activation of the transcription factor nuclear factor-κB (NF-κB), which controls expression of genes promoting cellular survival and proliferation. Much less, however, is known about the role of the transcription factor activator protein-1 (AP-1) in ABC DLBCL. Here, we show that AP-1, like NF-κB, was controlled by constitutive activation of the B-cell receptor signaling component caspase recruitment domain-containing membrane-associated guanylate kinase 1 (CARMA1) and/or the Toll-like receptor signaling component myeloid differentiation primary response gene 88 (MyD88) in ABC DLBCL cell lines. In contrast to germinal center (GC) B-cell (GCB) DLBCL, ABC DLBCL cell lines expressed high levels of the AP-1 family members c-Jun, JunB, and JunD, which formed heterodimeric complexes with the AP-1 family members activating transcription factor (ATF) 2, ATF3, and ATF7. Inhibition of these complexes by a dominant-negative approach led to impaired growth of a majority of ABC DLBCL cell lines. Individual silencing of c-Jun, ATF2, or ATF3 decreased cellular survival and revealed c-Jun/ATF2-dependent control of ATF3 expression. As a consequence, ATF3 expression was much higher in ABC vs GCB DLBCL cell lines. Samples derived from DLBCL patients showed a clear trend toward high and nuclear ATF3 expression in nodal DLBCL of the non-GC or ABC subtype. These findings identify the activation of AP-1 complexes of the Jun/ATF-type as an important element controlling the growth of ABC DLBCL

Bochum Assessment of Avoidance-based Emotion Regulation for Children (BAER-C): Development and evaluation of a new instrument measuring anticipatory avoidance-based emotion regulation in anxiety eliciting situations.

Avoidance-based emotion regulation plays a central role in the development and maintenance of anxiety disorders across the life span. However, measures for children that account for different avoidance strategies, are scarce. Derived from Gross' Process Model of Emotion Regulation, the Bochum Assessment of Avoidance-based Emotion Regulation for Children (BAER-C) was developed to assess avoidance strategies (cognitive avoidance, behavioural avoidance, verbal reassurance, and social reassurance) and reappraisal in anticipatory anxious situations. In the present study, the BAER-C was administered to 129 school children aged 8 to 14 and 199 children with anxiety disorders aged 8 to 16 and their parents, along with established measures on anxiety, psychopathology, and emotion regulation. Factor structure, internal consistency, convergent, divergent and construct validity were analysed. Results of the anxious sample showed a satisfactory internal consistency (McDonald's ω = .94) for all scales as well as positive correlations with anxiety symptoms (all rs > .17, all ps < .05). Factor analysis supported a five-factor model. This model was confirmed in the student sample. Children with an anxiety disorder scored higher on behavioural avoidance, verbal reassurance, and social reassurance than school children (F (5,304) = 12.63, p = .003, ηp2 = .17). Results for construct validity were ambiguous. Our analyses suggest that the BAER-C is a promising theory-based new instrument to reliably assess different avoidance strategies in children. More research is needed to further analyse construct validity with other emotion regulation questionnaires

Identifying characteristics of non-completers in fear conditioning paradigms with children and adolescents

The number of studies on fear conditioning in children and adolescents has increased in recent years. Most of these studies exclusively focus on data of completers while dropout rates, reasons for dropout, and specific characteristics of non-completers are underreported. This study systematically investigated data of 283 children and adolescents between 8 and 17 years (M = 11.10, SD = 2.14) undergoing a differential fear conditioning paradigm using a female scream as unconditioned stimulus (US). The sample included 230 children and adolescents with a current primary anxiety disorder (separation anxiety disorder, social anxiety disorder, and specific phobia) and 53 non-anxious controls. The dropout rate was 24.1%. The most common reason to discontinue was being afraid of the US (59.1%) followed by the startle probe being too loud (15.2%). Logistic regressions revealed that younger age and a present anxiety disorder predicted dropout. There seem to be distinct characteristics potentially predicting dropout from fear conditioning paradigms. Thus, interpretability and generalizability of those paradigms are limited when non-completers are not considered. Future research should conscientiously look at these data more closely and investigate paradigms that work independent of age and diagnostic status

Personalized assessment of anxiety and avoidance in children and their parents

In treating childhood anxiety disorders, therapists use highly individualized anxiety hierarchies to assess anxiety-eliciting situations and to personalize treatment. In contrast, psychometric assessment of anxiety symptoms in children usually consists of standardized questionnaires, assessing either total anxiety or disorder-specific symptom scores, prioritizing comparability over individual information. To account for interindividual differences, the Anxiety and Avoidance Scale for Children (AVAC) was developed, following a precise, personalized, assessment approach. In responding to the questionnaire, children and parents identify the most anxiety-eliciting situations before starting treatment, and rate them for anxiety and avoidance. Ratings are repeated over the course of treatment. The aim of this study is to introduce the new questionnaire and present first data on psychometric properties. The AVAC was administered to 389 children with separation anxiety disorder ($\it N$ = 148), social anxiety disorder ($\it N$ = 110) or specific phobia ($\it N$ = 131) aged 8 to 16 and their parents, along with other measures of anxiety and psychopathology before and after cognitive behavioral treatment. Results showed adequate to good test-retest reliability. The AVAC items correlated significantly with established anxiety questionnaires, indicating convergent construct validity. Regarding divergent construct validity, the AVAC showed only small correlations with externalizing symptoms, demonstrating its precision in measuring anxiety and avoidance. The questionnaire was also sensitive to change after treatment, with medium to large effects in the reduction of anxiety and avoidance. The present analyses suggest that the new personalized assessment approach with the AVAC is a reliable and valid assessment of individualized anxiety and avoidance, as well as change in those constructs over the course of CBT treatment

Bochum Assessment of Avoidance-based Emotion Regulation for Children (BAER-C)

Avoidance-based emotion regulation plays a central role in the development and maintenance of anxiety disorders across the life span. However, measures for children that account for different avoidance strategies, are scarce. Derived from Gross' Process Model of Emotion Regulation, the Bochum Assessment of Avoidance-based Emotion Regulation for Children (BAER-C) was developed to assess avoidance strategies (cognitive avoidance, behavioural avoidance, verbal reassurance, and social reassurance) and reappraisal in anticipatory anxious situations. In the present study, the BAER-C was administered to 129 school children aged 8 to 14 and 199 children with anxiety disorders aged 8 to 16 and their parents, along with established measures on anxiety, psychopathology, and emotion regulation. Factor structure, internal consistency, convergent, divergent and construct validity were analysed. Results of the anxious sample showed a satisfactory internal consistency (McDonald's $\omega$ = .94) for all scales as well as positive correlations with anxiety symptoms (all $\it rs$ > .17, all $\it ps$ < .05). Factor analysis supported a five-factor model. This model was confirmed in the student sample. Children with an anxiety disorder scored higher on behavioural avoidance, verbal reassurance, and social reassurance than school children ($\it F$ (5,304) = 12.63, $\it p$ = .003, $\eta$$_{p}^{2}$ = .17). Results for construct validity were ambiguous. Our analyses suggest that the BAER-C is a promising theory-based new instrument to reliably assess different avoidance strategies in children. More research is needed to further analyse construct validity with other emotion regulation questionnaires