Newest publications
The influence of social norms on expressing sympathy in social media
(2024) Graf-Drasch, Valerie; Gimpel, Henner; Bonenberger, Lukas; Blaß, Marlene; Graf-Drasch, Valerie; University of Hohenheim, Stuttgart, Germany; Gimpel, Henner; University of Hohenheim, Stuttgart, Germany; Bonenberger, Lukas; Branch Business & Information Systems Engineering of Fraunhofer FIT, Augsburg, Germany; Blaß, Marlene; Branch Business & Information Systems Engineering of Fraunhofer FIT, Augsburg, Germany
Increasingly, people are turning to social media to express grief. By and large, however, the social media community can do little more than improvise reactions, not quite sure how to use the old familiar social scripts as guides to lending effective support. To examine the role of social media in the grieving process, we used a mixed-methods approach: 12 interviews with “social media grievers” reveal the expectations of the bereaved regarding other users’ behavior. By way of two online experiments with 1058 participants, we tested how these expectations are met by the messaging of social media providers in accordance with social norm theory. We found that injunctive social norm messages are particularly effective, whereas descriptive social norm messages vary in their effectiveness, depending on which information is presented and how prominently so. What our study shows, then, is that both are potent socio-technical tools that can guide users towards more empathetic behavior when dealing with the bereaved, so while social media may not be a substitute for therapy, they can offer profound comfort for those of us dealing with bereavement and grief.
Arbuscular mycorrhizal fungi-based bioremediation of mercury: insights from zinc and cadmium transporter studies
(2023) Guo, Yaqin; Martin, Konrad; Hrynkiewicz, Katarzyna; Rasche, Frank; Guo, Y.; Faculty of Agricultural Sciences, Institute of Agricultural Sciences in the Tropics (Hans-Ruthenberg-Institute), University of Hohenheim, 70593, Stuttgart, Germany; Martin, K.; Faculty of Agricultural Sciences, Institute of Agricultural Sciences in the Tropics (Hans-Ruthenberg-Institute), University of Hohenheim, 70593, Stuttgart, Germany; Hrynkiewicz, K.; Department of Microbiology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, 87-100, Torun, Poland; Rasche, F.; Faculty of Agricultural Sciences, Institute of Agricultural Sciences in the Tropics (Hans-Ruthenberg-Institute), University of Hohenheim, 70593, Stuttgart, Germany
Phytoremediation, a sustainable approach for rehabilitating mercury (Hg)-contaminated soils, can be enhanced by arbuscular mycorrhizal (AM) fungi, which promote plant growth and metal uptake, including Hg, in contaminated soils. Hg, despite lacking a biological function in plants, can be absorbed and translocated using Zn and/or Cd transporters, as these elements belong to the same group in the periodic table (12/2B). In fact, the specific transporters of Hg in plant roots remain unknown. This study is therefore to provide fundamental insights into the prospect to remediate Hg-contaminated soils, with a focus on the role of AM fungi. The hypothesis posits that Hg uptake in plants may be facilitated by transporters responsible for Zn/Cd, affected by AM fungi. The Scopus database was used to collect studies between 2000 and 2022 with a focus on the ecological role of AM fungi in environments contaminated with Zn and Cd. Particular emphasis was laid on the molecular mechanisms involved in metal uptake and partitioning. The study revealed that AM fungi indeed regulated Zn and/or Cd transporters, influencing Zn and/or Cd uptake in plants. However, these effects vary significantly based on environmental factors, such as plant and AM fungi species and soil conditions (e.g., pH, phosphorus levels). Given the limited understanding of Hg remediation, insights gained from Zn and Cd transporter systems can guide future Hg research. In conclusion, this study underscores the importance of considering environmental factors and provides fundamental insights into the potential of Hg phytoremediation with the assistance of AM fungi.
Do we need post-tree thinning management? Prescribed fire and goat browsing to control woody encroacher species in an Ethiopian savanna
(2024) Abate, Teshome; Abebe, Tesfaye; Treydte, Anna; Abate, Teshome; College of Agriculture, Hawassa University, Hawassa, Ethiopia; Abebe, Tesfaye; College of Agriculture, Hawassa University, Hawassa, Ethiopia; Treydte, Anna; Department of Sustainable Agriculture and Biodiversity Conservation, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania
Worldwide, bush encroachment threatens rangeland ecosystem services, including plant biodiversity and forage for livestock. Various control methods for encroaching woody species and restoring herbaceous vegetation exist but have rarely been explored experimentally. We assessed the impact of post-tree thinning management on tree mortality, the herbaceous community, and overall rangeland condition in Borana, an Ethiopian savanna ecosystem. At two 1.4 ha areas of encroached mono-specific Vachellia drepanolobium (whistling thorn) stands, we set up twenty-four 20 × 10 m experimental plots with four post-tree-thinning treatments (goat browsing only (1), prescribed fire (2), fire and goat browsing (3), and control (4) (i.e., no management after tree cutting), with three replications in a complete block design. Over two growing periods, we monitored resulting tree mortality, coppicing, seedling mortality and recruitment, as well as herbaceous layer attributes (diversity, biomass) and overall rangeland condition. All three post-tree thinning management scenarios significantly enhanced tree mortalities, reduced seedling recruitment and increased the abundance of the dominant desirable grass species. Prescribed fire and fire and goat-browsing treatments resulted in significantly greater grass and forb species richness, forb diversity, and biomass, as well as the overall rangeland condition compared to goat browsing only and the control treatment. However, grass species diversity did not respond to treatments. Post-tree management significantly increased tree mortality, reduced seedling recruitment, and increased the abundance of desirable grass species. Our findings strongly suggest that post-thinning management, particularly prescribed fire or a combination of fire and browsing, is highly effective in suppressing woody encroachment and improving biomass and overall rangeland condition.
Composition of the ileum microbiota is a mediator between the host genome and phosphorus utilization and other efficiency traits in Japanese quail (Coturnix japonica)
(2022) Haas, Valentin; Vollmar, Solveig; Preuß, Siegfried; Rodehutscord, Markus; Camarinha-Silva, Amélia; Bennewitz, Jörn; Haas, Valentin; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Vollmar, Solveig; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Preuß, Siegfried; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Rodehutscord, Markus; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Camarinha-Silva, Amélia; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany; Bennewitz, Jörn; Institute of Animal Science, University of Hohenheim, Stuttgart, Germany
Background: Phosphorus is an essential nutrient in all living organisms and, currently, it is the focus of much attention due to its global scarcity, the environmental impact of phosphorus from excreta, and its low digestibility due to its storage in the form of phytates in plants. In poultry, phosphorus utilization is influenced by composition of the ileum microbiota and host genetics. In our study, we analyzed the impact of host genetics on composition of the ileum microbiota and the relationship of the relative abundance of ileal bacterial genera with phosphorus utilization and related quantitative traits in Japanese quail. An F2 cross of 758 quails was genotyped with 4k genome-wide single nucleotide polymorphisms (SNPs) and composition of the ileum microbiota was characterized using target amplicon sequencing. Heritabilities of the relative abundance of bacterial genera were estimated and quantitative trait locus (QTL) linkage mapping for the host was conducted for the heritable genera. Phenotypic and genetic correlations and recursive relationships between bacterial genera and quantitative traits were estimated using structural equation models. A genomic best linear unbiased prediction (GBLUP) and microbial (M)BLUP hologenomic selection approach was applied to assess the feasibility of breeding for improved phosphorus utilization based on the host genome and the heritable part of composition of the ileum microbiota.
Results: Among the 59 bacterial genera examined, 24 showed a significant heritability (nominal p ≤ 0.05), ranging from 0.04 to 0.17. For these genera, six genome-wide significant QTL were mapped. Significant recursive effects were found, which support the indirect host genetic effects on the host’s quantitative traits via microbiota composition in the ileum of quail. Cross-validated microbial and genomic prediction accuracies confirmed the strong impact of microbial composition and host genetics on the host’s quantitative traits, as the GBLUP accuracies based on the heritable microbiota-mediated components of the traits were similar to the accuracies of conventional GBLUP based on genome-wide SNPs.
Conclusions: Our results revealed a significant effect of host genetics on composition of the ileal microbiota and confirmed that host genetics and composition of the ileum microbiota have an impact on the host’s quantitative traits. This offers the possibility to breed for improved phosphorus utilization based on the host genome and the heritable part of composition of the ileum microbiota.
Occurrence of ‘Candidatus Mycoplasma haemosuis’ in fattening pigs, sows and piglets in Germany using a novel gap-based quantitative real-time PCR assay
(2022) Ade, Julia; Stadler, Julia; Ritzmann, Mathias; Zübert, Christina; Hoelzle, Katharina; Hoelzle, Ludwig E.; Ade, Julia; Institute of Animal Science, Department of Livestock Infectiology and Environmental Hygiene, University of Hohenheim, Stuttgart, Germany; Stadler, Julia; Clinic for Swine, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität Munich, Oberschleissheim, Germany; Ritzmann, Mathias; Clinic for Swine, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universität Munich, Oberschleissheim, Germany; Zübert, Christina; Institute of Animal Science, Department of Livestock Infectiology and Environmental Hygiene, University of Hohenheim, Stuttgart, Germany; Hoelzle, Katharina; Institute of Animal Science, Department of Livestock Infectiology and Environmental Hygiene, University of Hohenheim, Stuttgart, Germany; Hoelzle, Ludwig E.; Institute of Animal Science, Department of Livestock Infectiology and Environmental Hygiene, University of Hohenheim, Stuttgart, Germany
Background: The appearance of the novel porcine haemotrophic mycoplasma (HM) species ‘Candidatus Mycoplasma haemosuis’ was reported in apparently healthy but also in clinically sick animals in China, Korea and in a case report from Germany. Outside of Asia, however, nothing further is known about the frequency of ‘Ca. M. haemosuis’ in pigs to date. To investigate the distribution of this novel HM species in Germany, fattening pigs, sows and pre-suckling piglets were examined using a herein developed quantitative real-time PCR assay (qPCR). Because the piglets were sampled before the first colostrum uptake, additional information on a possible vertical transmission from dams to their offspring was obtained.
Results: Our novel qPCR assay successfully detected ‘Ca. M. haemosuis’ in all blood samples from the ‘Ca. M. haemosuis’-infected pigs. No cross-reactivity was detected when DNA from non-target Mycoplasma spp. and other bacterial species representing 105 bacteria/reaction were used as a template. The lower limit of detection of the qPCR was thus 10 gap gene copies per reaction and 2.5 x 103 genome equivalents (GE) per mL blood.
‘Candidatus M. haemosuis’ was detected by this qPCR in blood samples from a total out of 6.25% sows (13/208), 4.50% pre-suckling piglets (28/622) and 17.50% fattening pigs (35/200). On farm level, 3 out of 21 piglet producing farms (14.28%) and 9 out of 20 fattening farms (45.00%) were positive for ‘Ca. M. haemosuis’. Co-infections with M. suis were evident in all age groups.
Conclusion: ‘Candidatus M. haemosuis’ infection is present in German pig farms and the detection of the novel porcine HM species in piglets immediately after birth before colostrum intake indicates vertical transmission. The novel qPCR assay specific for ‘Ca. M. haemosuis’ described herein will be a prerequisite for future studies on the prevalence, epidemiology as well as the clinical and economic impact of ‘Ca. M. haemosuis’ infections.