Nitrogen from hairy vetch (Vicia villosa Roth) as winter green manure for white cabbage in organic horticulture

The effect of the nitrogen (N) supply from hairy vetch grown as winter green manure on white cabbage was investigated in field trials performed on an organic farm in north-west Germany over two years. Hairy vetch was either used as green manure or harvested. One of two bare-soil fallow treatments was supplied with hairy vetch shoot mass to serve as reference. In 2002 and 2003, hairy vetch and weeds accumulated 136 and 178 kg ha-1 of shoot N and yielded 3.79 and 4.72 t ha-1, respectively. After ploughing and planting white cabbage (Brassica oleracea L. convar. capitata var. capitata f. alba) for sauerkraut production at the beginning of June, the amount of soil mineral N (SMN) of the topsoil layer was biweekly investigated until canopy for about 6 - 8 weeks. In 2002, already within 2 weeks a maximum of 121 kg SMN ha-1 for the green manure hairy vetch treatment was reached, whereas in 2003 a maximum of only 60 kg SMN ha-1 was observed due to an exceptionally dry and warm season. In 2002, white cabbage shoot yielded an average 4.4 t DM ha-1 (range 3.9 - 5.1 t ha-1 DM) and had accumulated on average 153 kg N ha-1 (range 129 - 178 kg N ha-1). Mean fresh matter yield (FM) of a single head was only 1.2 kg (range 1.1 - 1.3 kg head-1) due to severe pest damage. In the following year, the mean head yield was 5.1 kg FM (range 3.4 - 6.4 kg) and head yield per hectare was 5.8 t DM (range 4.6 - 7.5 t DM ha-1) with a mean head N uptake of 182 kg ha-1 (range 136 - 237 kg N ha-1). The relationship between the weighted arithmetic daily mean of SMN for the first 6 - 8 weeks after the hairy vetch harvest date and the N uptake of cabbage at two sampling dates was significant, as were most correlations between presented core parameters. Although N of hairy vetch used as green manure calculatively recovered on average only about 27% in cabbage shoot N at final harvest, a balanced field N budget can be ensured by using the green manure legume hairy vetch as a basic N source for a subsequent white cabbage cash crop

Stickstoffversorgung der Zweitfrüchte Feldgemüse und Mais nach Winterzwischenfrucht-Leguminosen

Untersucht wurde die Stickstoffzufuhr mit dem Anbau von Leguminosen als Winterzwischenfrüchte (Zottelwicken, Inkarnatklee, Landsberger Gemenge, Wickroggen). Referenzvarianten waren Rübsen, Roggen und Gras in Reinsaat sowie Brache. In Feldversuchen an drei organisch bewirtschafteten Standorten im Rheinland wurden in den Jahren 2002 und 2003 die Zwischenfrüchte und Nachfruchtwirkung geprüft. Bestimmt wurden Ertrag (21 - 62 dt TM/ha), Stickstoffaufnahme (65 - 200 kg N/ha) und Netto-N-Fixierung (im Mittel 100 kg N/ha). Die Zwischenfrüchte wurden im Mai/Juni gemulcht oder beerntet. In den ersten Wochen nach Umbruch der Zwischenfrucht und Saat der Nachfrucht wurde der Verlauf der N-Mineralisierung im Boden gemessen (max. 50 - 180 kg Nmin-N/ha im Ap). Der Ertrag und die N-Aufnahme der Nachfrüchte Weißkohl und Mais betrug 877 - 1.274 dt FM/ha und 125 - 230 kg N/ha bzw. 138 - 196 dt TM/ha und 150 - 280 kg N/ha. Nach dem Verbleib des gemulchten Zwischenfruchtaufwuchses war im Vergleich zu den beernteten Varianten die N-Aufnahme der Nachfrüchte überwiegend signifikant höher. Bei Beerntung der Zwischenfrucht muß ein Großteil des für die Nachfrucht benötigten Stickstoffs aus dem Bodenvorrat gespeist werden, während mit dem Verbleib der Zwischenfrucht gemulcht auf der Fläche eine weitgehend ausgeglichene Stickstoff-Feldbilanz und damit Humusbilanz gestaltet werden kann. Gleichwohl war die mit dem Zwischenfruchtmulch zugeführte N-Menge nicht gleichermaßen als Differenz zwischen den gemulchten und beernteten Varianten der Nachfrucht wiederzufinden. Die N-Nachlieferung aus dem Boden überdeckte teilweise die Wirkung des gemulchten Zwischenfruchtaufwuchses. Mit Winterzwischenfrucht-Leguminosen kann ein mengenmäßig bedeutsamer Beitrag für die innerbetrieblich erzeugte N-Zufuhr geleistet werden. Auf Basis der vorgestellten Feldversuchsergebnisse wird eine Liste an Handlungsempfehlungen vorgestellt

A predictive model for the missing people problem

The disappearance of people is a multidimensional phenomenon, in which several aspects must be considered. It affects people’s security perception and consumes police resources in its treatment. Therefore, does exists an emotional circumstance for the relatives of the missing person. At the same, the police departments must develop a search task, in most cases with much uncertainty. In this research, a predictive model to predict missing people’s status is presented. The information used to create the model come from the Colombian legal Medicine Institute, in a public dataset composed of 6202 cases and 11 variables. The output variable was the final disappearance status, with the categories Appears Dead, Appears Alive, and Still Disappeared. Three supervised machine-learning algorithms were trained and tested for the model creation, K-Nearest Neighbours, Decision Trees, and Random Forest. The study was divided into three phases, first considering all the output categories. In the second phase, generating a binary classification for the Appeared and Not appeared instance. Thirdly, models were built to predict the status of appeared persons, Appears Alive or Appears Dead. The K-NN algorithm outperforms the other models with an Area under the curve value of 94.8%

Safety verification of asynchronous pushdown systems with shaped stacks

In this paper, we study the program-point reachability problem of concurrent pushdown systems that communicate via unbounded and unordered message buffers. Our goal is to relax the common restriction that messages can only be retrieved by a pushdown process when its stack is empty. We use the notion of partially commutative context-free grammars to describe a new class of asynchronously communicating pushdown systems with a mild shape constraint on the stacks for which the program-point coverability problem remains decidable. Stacks that fit the shape constraint may reach arbitrary heights; further a process may execute any communication action (be it process creation, message send or retrieval) whether or not its stack is empty. This class extends previous computational models studied in the context of asynchronous programs, and enables the safety verification of a large class of message passing programs

Parametric Forcing of Waves with Non-Monotonic Dispersion Relation: Domain Structures in Ferrofluids?

Surface waves on ferrofluids exposed to a dc-magnetic field exhibit a non-monotonic dispersion relation. The effect of a parametric driving on such waves is studied within suitable coupled Ginzburg-Landau equations. Due to the non-monotonicity the neutral curve for the excitation of standing waves can have up to three minima. The stability of the waves with respect to long-wave perturbations is determined $via$ a phase-diffusion equation. It shows that the band of stable wave numbers can split up into two or three sub-bands. The resulting competition between the wave numbers corresponding to the respective sub-bands leads quite naturally to patterns consisting of multiple domains of standing waves which differ in their wave number. The coarsening dynamics of such domain structures is addressed.Comment: 23 pages, 6 postscript figures, composed using RevTeX. Submitted to PR

Three-body resonances Lambda-n-n and Lambda-Lambda-n

Possible bound and resonant states of the hypernuclear systems $\Lambda nn$ and $\Lambda\Lambda n$ are sought as zeros of the corresponding three-body Jost functions calculated within the framework of the hyperspherical approach with local two-body S-wave potentials describing the $nn$, $\Lambda n$, and $\Lambda\Lambda$ interactions. Very wide near-threshold resonances are found for both three-body systems. The positions of these resonances turned out to be sensitive to the choice of the $\Lambda n$-potential. Bound $\Lambda nn$ and $\Lambda\Lambda n$ states only appear if the two-body potentials are multiplied by a factor of $\sim 1.5$.Comment: 12 pages, 5 figures. Acknowledgments are added in the new versio

Reachability of Communicating Timed Processes

We study the reachability problem for communicating timed processes, both in discrete and dense time. Our model comprises automata with local timing constraints communicating over unbounded FIFO channels. Each automaton can only access its set of local clocks; all clocks evolve at the same rate. Our main contribution is a complete characterization of decidable and undecidable communication topologies, for both discrete and dense time. We also obtain complexity results, by showing that communicating timed processes are at least as hard as Petri nets; in the discrete time, we also show equivalence with Petri nets. Our results follow from mutual topology-preserving reductions between timed automata and (untimed) counter automata.Comment: Extended versio

Transformational Leadership, Achievement Motivation, and Perceived Stress in Basic Military Training: A Longitudinal Study of Swiss Armed Forces

In Switzerland, military service is a civic obligation for all adult male citizens, and thus, leadership style can be particularly challenging. The present study investigated the impact of superiors’ leadership styles on recruits’ achievement motivation, organizational citizenship behavior (OCB), and perceived stress during their Basic Military Training (BMT). To this end, a total of 525 male recruits (mean age: 20.3 years) recruits were assessed both cross-sectionally and longitudinally. At the start of BMT (baseline), at week 7, and at week 11, participants completed a series of selfrating questionnaires covering demographic information, achievement motivation, organizational citizenship behavior (OCB), perceived stress, and their superiors’ leadership styles (transformational, transactional und laissez-faire). Longitudinally, scores for achievement motivation and OCB showed no significant difference between baseline and the 11th week. In a group comparison, the group experiencing higher transformational leadership (from week 7 to week 11) had the highest scores for achievement motivation and OCB, and the lowest scores for perceived stress, all at week 11. Exploratively, achievement motivation and OCB at baseline were associated with transformational leadership and transactional leadership at week 7 and week 11. Perceived stress at baseline correlated only with transformational leadership but not with transactional leadership, both at week 7 and week 11. Transformational leadership style fostered achievement motivation and OCB in Swiss military recruits and protected them from stress, both cross-sectionally and longitudinally.ISSN:2071-105

Comparative analysis of the lambda-interferons IL-28A and IL-29 regarding their transcriptome and their antiviral properties against hepatitis C virus.

Specific differences in signaling and antiviral properties between the different Lambda-interferons, a novel group of interferons composed of IL-28A, IL-28B and IL-29, are currently unknown. This is the first study comparatively investigating the transcriptome and the antiviral properties of the Lambda-interferons IL-28A and IL-29. Expression studies were performed by microarray analysis, quantitative PCR (qPCR), reporter gene assays and immunoluminometric assays. Signaling was analyzed by Western blot. HCV replication was measured in Huh-7 cells expressing subgenomic HCV replicon. All hepatic cell lines investigated as well as primary hepatocytes expressed both IFN-λ receptor subunits IL-10R2 and IFN-λR1. Both, IL-28A and IL-29 activated STAT1 signaling. As revealed by microarray analysis, similar genes were induced by both cytokines in Huh-7 cells (IL-28A: 117 genes; IL-29: 111 genes), many of them playing a role in antiviral immunity. However, only IL-28A was able to significantly down-regulate gene expression (n = 272 down-regulated genes). Both cytokines significantly decreased HCV replication in Huh-7 cells. In comparison to liver biopsies of patients with non-viral liver disease, liver biopsies of patients with HCV showed significantly increased mRNA expression of IL-28A and IL-29. Moreover, IL-28A serum protein levels were elevated in HCV patients. In a murine model of viral hepatitis, IL-28 expression was significantly increased. IL-28A and IL-29 are up-regulated in HCV patients and are similarly effective in inducing antiviral genes and inhibiting HCV replication. In contrast to IL-29, IL-28A is a potent gene repressor. Both IFN-λs may have therapeutic potential in the treatment of chronic HCV