Hybridization in the invasive Fallopia complex and its influence on sexual reproduction and herbivore resistance

Biological invasions are considered to be an important cause of current biodiversity loss and can cause significant ecological problems. Several hypotheses have been proposed to explain why exotic plants become invasive. An important determinant of the success of invasive plants in their adventive range is the efficiency of reproduction. High fecundity and the potential for sexual reproduction, which generates genetic variability but also vigorous clonal growth, are attributes frequently observed among the most successful invasive plants. However, external factors also can influence plant invasions. One commonly accepted mechanism for the invasion success of plants is that plants introduced into a new range experience less herbivory due to the release from natural enemies resulting in higher plant fitness. Furthermore, biological invasions may be promoted by climate change. Altered environmental conditions due to climate change could be more favourable for many invasive species and could increase the reproduction, establishment and spread of exotic plants in the introduced range. Recently, it has been claimed that the ability of exotic plants to establish and rapidly expand in a novel range may also be shaped by evolutionary processes. Interspecific hybridization has been identified as a stimulus for the evolution of increased invasiveness in exotic plant species. Hybridization can increase genetic variation and provide the genetic material on which natural selection can act. Novel gene combinations may result in phenotypes that are stronger competitors, have higher reproduction and survival rates and are more resistant against herbivory and may therefore be favoured by natural selection. Moreover, hybridization may facilitate adaptation to different or altered environmental conditions, for example, due to climate change. Successful hybrid genotypes might be fixed and retained by vegetative propagation and increase the invasion success of exotic plants. Taxa of the genus Fallopia (Polygonaceae), native to eastern Asia, are among the most troublesome invasive species worldwide and are particularly aggressive in Europe and North America. The plants cause significant damage to native ecosystems and are especially a problem along rivers. In Europe, exotic Fallopia plants spread mainly by vegetative propagation. Of the widespread F. japonica var. japonica in Europe only a single genotype with male-sterile flowers has been found, and sexual reproduction in the exotic Fallopia complex is thus restricted mainly to hybridization among the taxa. The naturalized but less frequent species F. sachalinensis can act as pollen donor, resulting in the hybrid F. x bohemica. The hybrid is frequent and considered to have a higher invasion potential and a faster spread than its parental species. A third introduced species is the climbing F. baldschuanica. Hybridization between this species and F. japonica var. japonica results in the hybrid F. x conollyana, which so far has only rarely been reported from Europe. In my dissertation I present four studies on hybridization in the invasive Fallopia complex in Western Europe and its consequences. Specifically, I studied the genetic diversity and hybridization patterns (chapter 2), extent and variation in sexual reproduction (chapter 3), regional variation in seedling establishment and the potential effects of climate change (chapter 4) and the influence of hybridization on herbivore resistance (chapter 5)

Jakobinismus als Wurzel des Journalismus

Meine Diplomarbeit beschäftigt sich mit der Frage, ob die Wurzel des modernen Journalismus im deutschen Jakobinismus zu suchen ist. Im Mittelpunkt der Untersuchung stehen die Biographien der meiner Meinung nach 65 wichtigsten deutschen und österreichischen Jakobinern und einer Jakobinerin, die zu diesem Zweck von mir erstellt wurden. Die Lebensläufe der ausgewählten Demokraten geben Aufschluss über deren Ausbildung, den beruflichen Werdegang und die publizistische Tätigkeit während der Französischen Revolution. Dadurch entstand eine Liste von 115 aufklärerischen Zeitungen bzw. Zeitschriften, für die angeführten Jakobiner entweder als Mitarbeiter tätig waren bzw. die von einem Jakobiner gegründet, herausgegeben, geleitet oder redigiert wurden. Aufgrund der Zeitungen und Zeitschriften ergaben sich die folgenden Zentren jakobinscher Publizistik: Linksrheinische Gebiete, Frankreich, Süddeutschland, Norddeutschland und das dänische Altona. Blätter, die nicht eingeordnet werden konnten, wurden extra angeführt. Auch die Lage in Preußen und Österreich wurde wegen der historischen und politischen Bedeutung besprochen. Die vorliegende Arbeit gibt einen Überblick über die historischen Ereignisse, die deutsche Publizistik zur Zeit der Französischen Revolution und widmet sich genauer der jakobinischen Medien und ihrer Darstellungsformen. Aufgrund meiner Forschung habe ich festgestellt, welch wichtigen Beitrag die jakobinischen Publizisten zur Entwicklung eines modernen Journalismus und des Berufes des Journalisten geleistet haben. Der Jakobinismus brachte verschiedene Neuerungen für den Journalismus. Die bedeutendste war wohl, dass die jakobinischen Publizisten es als ihre Pflicht ansahen, als Anwälte und Sprecher der niederen Bevölkerungsschichten, Kaufleute, Handwerker und Bauern über tagespolitische Themen in regelmäßigen Abständen - das Kriterium der Periodizität erfüllend - zu informieren. Alle Stände hatten plötzlich Zugang zu den Medien und konnten diese als Nachrichtenquelle nutzen. Jedoch ging es im ausgehenden 18. Jahrhundert nicht nur mehr um die Information an sich, sondern auch v.a. darum, Missstände und Ungerechtigkeiten aufzuzeigen. Zum ersten Mal in der Geschichte wurde in der Presse öffentlich Kritik geübt und eine Meinung geäußert. Es kam zur Entstehung einer Öffentlichkeit. Mit Hilfe der Biographien wurde gezeigt, dass ein kleiner Teil der Jakobiner als hauptberufliche politische Publizisten tätig waren. Aufgrund dieser Ergebnisse bin ich zu der Erkenntnis gekommen, dass es berechtigt ist, den Ursprung des modernen Journalismus im deutschen Jakobinismus festzusetzen. Die Frage, ob der Beruf des Journalisten zur Zeit der Französischen Revolution schon existierte, konnte in dieser Arbeit nicht beantwortet werden und verlangt weitere Forschung. Eine Untersuchung und Analyse der jakobinischen Zeitungen und Zeitschriften müsste durchgeführt werden, wodurch festgestellt werden könnte, ob die Jakobiner in ihren Artikeln das Prinzip der Unparteilichkeit befolgt haben. Sollte sich auch nur einer der hauptberuflichen jakobinischen Publizisten an den Grundsatz der Unparteilichkeit gehalten haben, so war dieser - so lautet die neue Hypothese - von Beruf Journalist und der Beruf existierte bereits im ausgehenden 18. Jahrhundert

The moderating effects of sex, age, and education on the outcome of combined cognitive training and transcranial electrical stimulation in older adults.

Computerized cognitive training (CCT) has been shown to improve cognition in older adults via targeted exercises for single or multiple cognitive domains. Combining CCT with non-invasive brain stimulation is thought to be even more effective due to synergistic effects in the targeted brain areas and networks. However, little is known about the moderating effects of sex, age, and education on cognitive outcomes. Here, we investigated these factors in a randomized, double-blind study in which we administered CCT either combined with transcranial direct (tDCS), alternating (tACS) current stimulation or sham stimulation. 59 healthy older participants (mean age 71.7 ± 6.1) received either tDCS (2 mA), tACS (5 Hz), or sham stimulation over the left dorsolateral prefrontal cortex during the first 20 min of a CCT (10 sessions, 50 min, twice weekly). Before and after the complete cognitive intervention, a neuropsychological assessment was performed, and the test scores were summarized in a composite score. Our results showed a significant three-way interaction between age, years of education, and stimulation technique (F(6,52) = 5.53, p = 0.007), indicating that the oldest participants with more years of education particularly benefitted from tDCS compared to the sham group, while in the tACS group the youngest participants with less years of education benefit more from the stimulation. These results emphasize the importance of further investigating and taking into account sex, age, and education as moderating factors in the development of individualized stimulation protocols. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov, identifier NCT03475446

Clock monitoring is associated with age-related decline in time-based prospective memory

In laboratory time-based prospective memory tasks, older adults typically perform worse than younger adults do. It has been suggested that less frequent clock checking due to problems with executive functions may be responsible. We aimed to investigate the role of clock checking in older adults’ time-based prospective memory and to clarify whether executive functions would be associated with clock checking and consequently, with time-based prospective memory. We included 62 healthy older adults (62-85 years of age) and applied tasks of time-based prospective memory as well as of executive functions (i.e., inhibition, fluency, and working memory). We used mediation analysis to test whether time-based prospective memory declined with advancing age due to less frequent clock checking. In addition, we tested whether there would be an association between executive functions and clock checking or time-based prospective memory. Time-based prospective memory declined with advancing age due to less frequent clock checking within 30s prior to intention completion. We only found a link between executive functions and clock checking (or time-based prospective memory) when not controlling for age. Our results support the importance of clock checking for time-based prospective memory and add to the current literature that older adults’ prospective memory declines because they are less able to adapt their clock checking. Yet, the reason why older adults are less able to adapt their clock checking still remains open. Our results do not indicate that executive function deficits play a central role

Innovative Industry: Environmental horticulture professionals’ perceptions on wildlife-friendly plants and a potential certification offering

Plants can improve people’s lives and mental health, but consumers have become increasingly concerned about the impact of plant production practices on the environment and wildlife. Previous research has not explored the interest and ability of plant producers and suppliers to provide wildlife friendly plant options for consumers. The University of Florida is considering the development of a wildlife-friendly plant certification to enhance production protocols for growers and connect consumers to sustainable plant options. This study explored perceptions of this certification through 11 in-depth interviews with environmental horticulture professionals. The study was guided by the following research questions: 1) What experiences do environmental horticulture professionals have with wildlife-friendly plants?, 2) What trends do environmental horticulture professionals see with consumers?, 3) What are the benefits and barriers to adopting this wildlife-friendly plant certification?, and 4) What communication strategies are needed to make this wildlife-friendly plant certification viable? Results indicate environmental horticulture professionals recognize the advantages of wildlife-friendly plants. However, the interviews revealed specific barriers to adoption and communication considerations that would impact certification diffusion. Implications of this research include a need for strategic programming regarding the wildlife-friendly plant certification and cohesive communication strategies among environmental horticulture organizations to educate professionals and consumers about wildlife-friendly plant options

Leveraging Skype in the Classroom for Science Communication: A Streaming Science – Scientist Online Approach

A growing need exists to identify, implement, and research alternative methods to communicate with, educate, and engage youth about science, in order to increase science literacy and knowledge of future societal decision-makers. Electronic field trips (EFTs) are one channel of non-formal communication and education that have been introduced in agricultural and natural resources to reach youth audiences with science-based information in real-time. EFTs can be conducted in several different ways due to the proliferation of video production and web-streaming technologies. The following professional development article offers science communication professionals and scientists a detailed model and specific steps to develop and host an EFT via the Skype in the Classroom platform. The outlined model builds off of prior application and research from the Streaming Science online science communication platform and offers a secondary model for effective EFT implementation and research. The authors describe the establishment of an online science communication network, the development of the Streaming Science: Scientist Online format, content creation, the production team structure, and mobile production hardware and software. Scientist Online EFT program outcomes in terms of participation are noted, as well as student outcomes in the form of excerpts to demonstrate student engagement are shared

Broadened assessments, health education and cognitive aids in the remote memory clinic

The prevalence of dementia is increasing and poses a health challenge for individuals and society. Despite the desire to know their risks and the importance of initiating early therapeutic options, large parts of the population do not get access to memory clinic-based assessments. Remote memory clinics facilitate low-level access to cognitive assessments by eschewing the need for face-to-face meetings. At the same time, patients with detected impairment or increased risk can receive non-pharmacological treatment remotely. Sensor technology can evaluate the efficiency of this remote treatment and identify cognitive decline. With remote and (partly) automatized technology the process of cognitive decline can be monitored but more importantly also modified by guiding early interventions and a dementia preventative lifestyle. We highlight how sensor technology aids the expansion of assessments beyond cognition and to other domains, e.g., depression. We also illustrate applications for aiding remote treatment and describe how remote tools can facilitate health education which is the cornerstone for long-lasting lifestyle changes. Tools such as transcranial electric stimulation or sleep-based interventions have currently mostly been used in a face-to-face context but have the potential of remote deployment—a step already taken with memory training apps. Many of the presented methods are readily scalable and of low costs and there is a range of target populations, from the worried well to late-stage dementia

Yeast XRS2 and human NBN gene: Experimental evidence for homology using codon optimized cDNA

The genes, XRS2 in Saccharomyces cerevisiae and NBN in mammals, have little sequence identity at the amino acid level. Nevertheless, they are both found together with MRE11 and RAD50 in a highly conserved protein complex which functions in the repair of DNA double-strand breaks. Here, we have examined the evolutionary and functional relationship of these two genes by cross-complementation experiments. These experiments necessitated sequence correction for specific codon usage before they could be successfully conducted. We present evidence that despite extreme sequence divergence nibrin can, at least partially, replace Xrs2 in the cellular DNA damage response, and Xrs2 is able to promote nuclear localization of MRE11 in NBS cells. We discuss that the extreme sequence divergence reflects a unique adaptive pressure during evolution related to the specific eukaryotic role for both Xrs2 and nibrin in the subcellular localisation of the DNA repair complex. This, we suggest, is of particular relevance when cells are infected by viruses. The conflict hypothesis of co-evolution of DNA repair genes and DNA viruses may thus explain the very low sequence identity of these two homologous genes