DaKS - University of Kassel's research data repository

DaKS is the institutional repository of the University of Kassel for research data. It offers structured storage of research data alongside with descriptive metadata, long-term archiving for at least 10 years and – if requested – the publication of the dataset with a DOI.

DaKS is managed by the university library and the IT Service Centre of the University of Kassel. It is hosted at Philipps-Universität Marburg. We are happy to advise you via daks@uni-kassel.de.

Recent Submissions

Research Data

Effect of Various Organic Mulches on Aphids, Their Predators, and Potato Virus Transmission [Dataset]

(Universität Kassel) Winkler, Julian; Kirchner, Sascha M.; Hensel, Oliver

Potato virus Y (PVY) and potato leafroll virus (PLRV) are two viruses of major economic importance in potato cultivation. Several studies have demonstrated that the transmission of non-persistently transmitted PVY can be reduced through the use of straw mulch. However, little is known about the impact of other mulch materials and their influence on persistently transmitted PLRV. The impact of triticale/ vetch, grass/clover, grass silage, and straw mulch was thus investigated in five field trials. Aphid flight activity was monitored using yellow water traps, and vector pressure was calculated based on species-specific relative efficiency factors. The occurrence of aphids and their predators on potato plants were assessed by visual counts. Harvested tubers were tested for their virus incidence for both PVY and PLRV. The results demonstrated that all mulch treatments significantly reduced aphid landings by 30–75% compared to the unmulched control, with the greatest reduction observed for Myzus persicae. Consequently, PVY vector pressure was substantially lower in mulched plots. Mulching with triticale/vetch, grass/clover, and straw significantly decreased PVY incidence by up to 75%. However, the overall incidence of PLRV was too low to make a conclusive statement about the effect of mulch on PLRV transmission. Aphid abundances and numbers of aphid predators on the plants were generally lower in mulched plots. These results demonstrate that organic mulches can be an effective cultural control measure against aphid-transmitted potato viruses, as they disrupt vector landing early in crop development and potentially reduce within-field spread.

Research Data

Effect of organic mulching in potatoes on ground-dwelling predator species [Dataset]

(Universität Kassel) Winkler, Julian; Leisch, Simeon; Kirchner, Sascha M.

This repository contains data and R code from three large-scale field experiments (2021a, 2021b, and 2022) conducted on organic potato fields near Witzenhausen / Göttingen, Germany, investigating the effects of different organic mulching treatments (triticale/vetch, straw, grass silage) versus unmulched controls on ground-dwelling generalist predators—specifically carabid beetles and spiders. These predators provide essential ecosystem services in agriculture by preying on pests, but their biodiversity is threatened by intensification, pesticide use, and climate change. Arthropods were sampled using pitfall traps, yielding 12,076 carabids (42 taxa) and 2,399 spiders (38 taxa). Organic mulching, particularly with triticale/vetch, significantly increased the abundance of key beneficial species such as Bembidion lampros, B. quadrimaculatum, Poecilus cupreus (carabids), and Erigone atra, E. dentipalpis, Agyneta rurestris (spiders). Community composition differed markedly between mulched and control plots, as shown by NMDS and PERMANOVA analyses, likely due to increased habitat complexity, altered microclimate, and enhanced prey availability under mulch. The dataset consists of species-level arthropod counts. R code is provided for data cleaning, descriptive summaries, mixed model analyses, diversity and ordination analyses, indicator species tests, and visualization (using tidyverse, vegan, glmmTMB, DHARMa, multcomp). These resources enable reproducible analysis of how organic mulching supports beneficial arthropod populations and contributes to integrated pest management.

Research Data

Validation of real-time aging simulation of poly(lactic acid) (PLA) using accelerated aging in accordance with ASTM F1980 [Dataset]

(Universität Kassel) Krug, Natalie; Zarges, Jan-Christoph; Chettouh, Chaimae; Heim, Hans-Peter

To advance the application of bio-based materials in medical technology, further research is required to assess their long-term performance. In common practice, accelerated aging tests based on ASTM F1980 are used in medical contexts to predict material behavior over time. This standard provides calculation guidelines to determine the equivalent storage duration under artificially accelerated aging conditions using a Q10-factor. This factor, typically assumed to be 2, represents the increase in reaction rate due to elevated temperatures.
In this study, a comparison was conducted between accelerated aged samples and their real-time equivalents using various PLA types. The results indicate that the standard assumption of Q10 = 2 can lead to an overestimation of degradation, resulting in a misrepresentation of real-time aging behavior. This discrepancy is substantiated by experimental data, including mechanical, thermal, and chemical analyses. A key factor contributing to this deviation appears to be the reliance on overly simplistic assumptions regarding degradation kinetics, which fail to account for autocatalytic reactions and the inherently multi-stage nature of the degradation process. In the present study, this observation was further corroborated through the determination of material-specific Q10-factors. These factors, found to range between 2.3 and 2.5, exhibited dynamic variations throughout the degradation process, highlighting the need for a refined approach to accelerated aging methodologies.

Research Data

High-Resolution Differential Topography Measurement Using Adaptive Linnik Interferometry [Dataset]

(Universität Kassel) Stelter, Andre; Meyer, Christian; Käkel, Eireen; Hillmer, Hartmut; Lehmann, Peter

In order to validate a new sample alignment algorithm, measurements were performed by a home-built Linnik interferometer (100x, NA=0.90 and 133x, NA = 1,1). The dataset contains image stacks obtained by the Linnik interferometer. Two Measurements were carried out as an adaptive measurement where the reference object ist the same as the measurement object. The remaining measurements were carried out in a conventional manner with a plane mirror as reference.

If you use the data please refer to our corresponding article mentioned below.

Research Data

Rigorous full 3D modeling of coherence scanning interferometry and confocal microscopy [Dataset]

(Universität Kassel) Pahl, Tobias; Rosenthal, Felix; Künne, Marco; Käkel, Eireen; Diehl, Michael; Hagemeier, Sebastian; Hillmer, Hartmut; Lehmann, Peter

In order to validate a rigorous simulation model for confocal microscopes and coherence scanning interferometers, measurements were performed by a home-built Linnik interferometer (100x, NA=0.95) and a commercial confocal microscope (150x, NA=0.95). The dataset contains image stacks obtained by the Linnik interferometer for TE-, TM-, and unpolarized light. Additionally, the gratings reconstructed using a combination of envelope and phase analysis are included. In case of the confocal microscope, image stacks are not available, so only the reconstructed grating is stored. For further discussion, an AFM measurement result (tip radius 10 nm) is given as well.
If you use the data please refer to our corresponding article mentioned below.