Press releases

FRANKFURT. Since about 25 years, animal species in West and Central Africa are no longer being hunted solely for the purpose of local self-sufficiency, but increasingly also for sale in urban areas several hundred kilometres away. As a consequence, many populations have dramatically decreased or already disappeared altogether. A team of European researchers led by Goethe University Frankfurt has now predicted hunting pressure for the Congo Basin and produced a detailed map, which could help in regional planning.

The hunted species are mostly mammals, but also some reptile and bird species. In many areas, they are the only cheap and easily available source of animal protein for the rural community. However, the commercialization of the bushmeat trade has meanwhile led also to the “Empty Forest Syndrome” in forest ecosystems throughout Africa. The sale of bushmeat allows the rural community to purchase products or services which go beyond simple self-sufficiency. This has far-reaching ecological consequences, which ultimately also threaten the existence of the rural population. For example, with the disappearance of the herbivorous animals which serve as seed carriers, the forests disappear in the long term too.

The research team led by Bruno Streit analysed reports published between 1990 and 2007 on the bushmeat on sale on markets in the Congo Basin (Cameroon, Central African Republic, Democratic Republic of the Congo, Equatorial Guinea, Gabon and the Republic of the Congo). On the basis of the number of carcasses openly on sale and the catchment area of the markets, they calculated the annual harvest rates of bushmeat per square kilometre. They then correlated these figures with socio-economic variables, such as population density, the density of the road network and the distance of the markets to the nature reserves. In a further step, they defined different classes of potential hunting pressure.

“For a quarter of the total area, we calculated a level of hunting pressure which was somewhat lower”, explains Professor Bruno Streit of the Institute of Ecology, Evolution and Diversity at Goethe University Frankfurt. “However, our prediction foresees severe to very severe hunting pressure across 39 percent of the area of the Congo Basin. This is the case above all in areas with a very dense network of traffic routes, often in proximity to nature reserves”, continues Stefan Ziegler of the WWF. Thus the internationally famous Virunga National Park and the Okapi Wildlife Reserve in the east of the Democratic Republic of the Congo also lie in such areas.

The map produced by the researchers could help to support sustainable regional planning by ensuring that - as far as possible - roads do not carve up areas rich in wildlife. The map also identifies neuralgic points where the potential for hunting pressure is particularly high. Anti-poaching measures should concentrate on these zones.

The report stemmed from a joint project between Goethe University Frankfurt, experts in remote sensing at the University of Würzburg, and conservationists from WWF Germany.

Publication: Stefan Ziegler, John E. Fa, Christian Wohlfart, Bruno Streit, Stefanie Jacob and Martin Wegmann: Mapping Bushmeat Hunting Pressure in Central Africa, in: Biotropica, 29 Januar 2016 DOI: 10.1111/btp.12286; http://onlinelibrary.wiley.com/doi/10.1111/btp.12286/abstract

Pictures for dowload: www.uni-frankfurt.de/59967888

Information: Prof. Bruno Streit, Institute for Ecology, Evolution and Diversity, Campus Riedberg, Tel.: (069) 798-42160, -42162, streit@bio.uni-frankfurt.de.

FRANKFURT. In contrast to animals, plants form new organs throughout their entire life, i.e. roots, branches, flowers and fruits. Researchers in Frankfurt wanted to know to what extent plants follow a pre-determined plan in the course of this process. In the renowned journal “Current Biology”, they describe the growth of secondary roots of thale cress (Arabidopsis thaliana). They have observed it cell by cell in a high-tech optical microscope and analysed it with computer simulations. Their conclusion: root shape is determined by a combination of genetic predisposition and the self-organization of cells.

“Our work shows the development of the complex organ of the secondary root with unprecedented temporal and spatial resolution”, says Professor Ernst H. K. Stelzer of the Buchmann Institute for Molecular Life Sciences at Goethe University Frankfurt am Main. He is the inventor of the high-resolution and gentle light sheet fluorescence microscopy, with which the researchers recorded the development of secondary roots from the first cell division to their emergence out of the main root. For over 64 hours, they first logged the fluorescence signals from cell nuclei and plasma membrane every five minutes and then identified and followed all cells involved in root development.

The secondary roots stem from a variable number of “founder cells”, of which some contribute to the development. The shape of the secondary roots and the respective growth curves show great similarities. “We classified the cell divisions on the basis of their spatial orientation in order to find out when new cell lines and cell layers form”, explains Daniel von Wangenheim, first author of the study. “Surprisingly, we were not able to predict on the basis of the initial spatial arrangement where exactly the future centre of the secondary root would lie.” Evidently, only the first division of the founder cells is strongly regulated, whilst the subsequent divisions do not follow any pre-determined pattern. Their behaviour is rather more adaptive. In nature, this also makes sense, for example if the roots meet with an obstacle.

In order to be able to identify the fundamental principles of secondary root development in the vast amount of data, the researchers combined methods for the quantitative analysis of cell divisions in wild and genetically modified plants (wild type and mutants) with mathematical modelling. This  was undertaken by their colleague Prof. Alexis Maizel from the University of Heidelberg. He realized that the development of the secondary root is based on a limited number of rules, which account for the growth and orientation of cells. The development of a characteristic secondary root follows the principles of self-organization, which is prevalent in nature.  Alexander Schmitz, co-author of the study, explains the non-deterministic part by the fact that organ development is robust as a result: “In this way, the roots are able to develop in a flexible and nevertheless controlled manner despite the varying arrangement of the cells and mechanical factors in the surrounding tissue.”

Publication: Daniel von Wangenheim, Jens Fangerau, Alexander Schmitz, Richard S. Smith, Heike Leitte, Ernst H.K. Stelzer, Alexis Maizel: Rules and self-organizing properties of post-embryonic plant organ cell division patterns, in: Current Biology, 28.1.2016, DOI: doi:10.1016/j.cub.2015.12.047

Online publication: http://dx.doi.org/10.1016/j.cub.2015.12.047

Video on YouTube: https://youtu.be/OffLqVUI8hE

Information: Prof. Dr. Ernst H. K. Stelzer, Alexander Schmitz, Buchmann Institute for Molecular Life Science, Goethe University, Phone +49(0)69 798-42547 or -42551, ernst.stelzer@physikalischebiologie.de alexander.schmitz@physikalischebiologie.de

Tracing distinct proteins in cells is like looking for a needle in a haystack. In order to localize proteins and decipher their function in living cells, researchers label them with fluorescent molecules. However, the delivery of protein markers is often insufficient. A group of researchers from the Goethe University, working in close collaboration with US colleagues, has now found a solution for this problem. In the current issue of Nature Communications, they report on a process that uses pressure to deliver chemical probes in a fine-tuned manner into living cells.

"Although more and more protein labeling methods utilize synthetic fluorescent dyes, they often suffer from problems such as cell permeability or low labeling efficiency. Moreover, they cannot always be combined with other protein labeling techniques", explains Dr. Ralph Wieneke from the Institute of Biochemistry at the Goethe University.

Recently, the working group led by Wieneke and Prof. Robert Tampé developed a marker that localizes selected proteins in cells with nanometre precision. This highly specific lock-and-key element consists of the small synthetic molecule trisNTA and a genetically encoded His-tag.

In order to deliver this protein marker into cells, the researchers from Frankfurt, together with colleagues from the Massachusetts Institute of Technology (MIT), Cambridge, USA, applied a procedure in which a mixture of cells together with the marker were forced through narrow constrictions. This process is called cell squeezing. Under pressure, the cells incorporate the fluorescent probes with an efficiency rate greater than 80 percent. In addition, the process enabled to squeeze one million cells per second through the artificial capillary in high-throughput.

Since the marker binds very efficiently and specifically to the target protein and its concentration can be precisely regulated within the cell, the researchers were able to record high resolution microscopy images in living cells. Moreover, they were able to trace proteins with the marker only when activated by light. Thus, cellular processes can be observed with high precision in terms of space and time.

The researchers can even combine their labeling methods with other protein labeling techniques in living cells to observe several proteins simultaneously in real time. "Utilizing cell squeezing, we were able to deliver a number of fluorescently labeled trisNTAs in cells. This tremendously expands the scopes of conventional as well as high resolution microscopy in living cells", explains Prof. Robert Tampé. In future, it will be possible to follow dynamic processes in living cells in time and space at high resolution.

A picture is available for downloading here: www.uni-frankfurt.de/59861753

Caption: Utilizing the small lock-and-key element, the nuclear envelope protein Lamin A was stained with fluorescently labeled trisNTA (green). By orthogonal labeling methods, other proteins can be visualized simultaneously within the same cell (Histon 2B in magenta; Lysosomes in blue; Microtubuli in red).

Publication Alina Kollmannsperger, Armon Sharei, Anika Raulf, Mike Heilemann, Robert Langer, Klavs F. Jensen, Ralph Wieneke & Robert Tampé: Live-cell protein labelling with nanometre precision by cell squeezing, in: Nature Communications, 7:10372,

DOI: 10.1038/ncomms10372

www.nature.com/naturecommunications

Information: Dr. Ralph Wieneke, Institute for Biochemistry, Riedberg Campus, Tel.: (069) 798-29477, wieneke@em.uni-frankfurt.de.

Following a nomination by the Research Center SAFE, the Alexander von Humboldt Foundation has granted an Anneliese Maier Research Award 2016 to Marti G. Subrahmanyam, Charles E. Merrill Professor of Finance, Economics and International Business at the Stern School of Business, New York University. Purpose of the grant is the promotion of international cooperation in the humanities and social sciences. The award of 250,000 EUR will be used over a period of five years to finance research cooperation between Subrahmanyam and SAFE/Goethe University. The official host will be Loriana Pelizzon, SAFE Professor of Law and Finance.

Marti Subrahmanyam has published numerous articles and books in the area of corporate finance, capital markets and international finance. His current research interests are the valuation of corporate securities, options and futures markets, corporate debt markets, market microstructure and liquidity, and Indian financial markets. Subrahmanyam studied at the Indian Institute of Management and the Indian Institute of Technology Madras before he started his doctoral studies at the Massachusetts Institute of Technology (MIT) in Cambridge, USA, where he earned a Ph.D. in 1974.

FRANKFURT. Social difficulties are one of the main problems for children and adolescents with Autism Spectrum Disorder (ASD). Especially when their intelligence is unaffected, they become more and more conscious in the course of their development of the fact that they are different. In the framework of group therapy developed at Goethe University Frankfurt, children and adolescents with high functioning ASD can learn how to cope better in the social world and also achieve a lasting effect. This is confirmed by clinical trials which examined 209 children and adolescents between the ages of 8 and 18 over the course of three years.

“We often encounter children and adolescents with Autism Spectrum Disorder in clinical practice who would like to communicate with youngsters of their own age and at the same time experience every day that they meet with rejection because they are unable to understand many of their classmates’ behaviour patterns. And this causes them to despair”, explains Professor Christine Freitag, Head of the Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy. Together with Dr. Hannah Cholemkery, she has developed a behavioural group therapy programme with instructions and exercises for the improvement of social skills.

To date, group therapies for the training of social skills for people with ASD have predominantly been investigated in the USA in the framework of smaller trials without any measurement of stability. The objective of the “SOSTA-net Trial”, led by Christine Freitag and coordinated by Hannah Cholemkery and in which six university hospitals in Germany participated, was to examine whether the social responsiveness of children and adolescents with ASD could be raised by means of group-based behavioural therapy. This took place with the aid of a standardized questionnaire (on the basis of a Social Responsiveness Scale – SRS), in which 65 behaviour patterns were evaluated by the parents before the start of group therapy, at the end of the intervention as well as three months after the end of the intervention in order to measure stability.

Therapy took place once a week over the course of three months in a group with four to five youngsters of the same age and two therapists. There were also three parent evenings. The results were compared with those of a wait list control group. There was a clear improvement in social behaviour in the intervention group, which also remained stable after three months when examined again.

In particular children with severe symptoms and a higher IQ at the beginning of the therapy were able to profit from it.

Publication:

Christine Freitag, Hannah Cholemkery et al.: Group-based cognitive behavioural psychotherapy for children and adolescents with ASD: the randomized, multicentre, controlled SOSTA - net trial, in: Journal of Child Psychology and Psychiatry (2015), DOI: 10.1111/jcpp.12509

http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1469-7610/earlyview

Further information: Professor Dr. Christine M. Freitag, Dr. Hannah Cholemkery, Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy, Tel.: (069) 6301-84055, Hannah.Cholemkery@kgu.de