196,065 research outputs found
Die Porphyrkuppenlandschaft des unteren Saaletals - Vegetationsdynamische Untersuchungen auf kleinflächigen Kuppen unterschiedlicher Entstehungszeit
No full textPartzsch M, Scherf W, Hensen I. Die Porphyrkuppenlandschaft des unteren Saaletals - Vegetationsdynamische Untersuchungen auf kleinflächigen Kuppen unterschiedlicher Entstehungszeit. Tuexenia 23. 2003;23:227-255
Plasticity and Adaptation in Neuromorphic Biohybrid Systems
No full textNeuromorphic systems take inspiration from the principles of biological information processing to form hardware platforms that enable the large-scale implementation of neural networks. The recent years have seen both advances in the theoretical aspects of spiking neural networks for their use in classification and control tasks and a progress in electrophysiological methods that is pushing the frontiers of intelligent neural interfacing and signal processing technologies. At the forefront of these new technologies, artificial and biological neural networks are tightly coupled, offering a novel “biohybrid” experimental framework for engineers and neurophysiologists. Indeed, biohybrid systems can constitute a new class of neuroprostheses opening important perspectives in the treatment of neurological disorders. Moreover, the use of biologically plausible learning rules allows forming an overall fault-tolerant system of co-developing subsystems. To identify opportunities and challenges in neuromorphic biohybrid systems, we discuss the field from the perspectives of neurobiology, computational neuroscience, and neuromorphic engineering. © 2020 The Author(s
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Zur Keimungsbiologie acht ausgewählter kurzlebiger Ruderal- und Segetalarten
No full textPartzsch, M.: Germination biology of eight short-living ruderal and segetal species – Hercynia N. F.43 (2010): 149 –166.Knowledge on the germination behaviour of plant species allows to draw conclusions to be drawn ontheir associated regeneration capacity. Open field observations indicate that short-living species oftenproduce high numbers of seedlings. For this study we collected samples from eight species (Berteroaincana, Camelina microcarpa, Lepidium campestre, Medicago lupulina, Microrrhinum minus, Odontitesvulgaris, Thlaspi arvense and Trifolium arvense) which commonly occur throughout a climatic dryregion in central Germany in the vicinity of Halle/S. to investigate their germination behaviour underdifferent temperature and light conditions.A proportion of the mature seeds collected was used for an initial germination experiment while therest were buried in soil to ensure hibernation until the following experiment phase under similar conditionsthe following spring. The germination experiments were carried out under cold (8/4 °C), regular(20/10 °C) and hot (32/20 °C) temperature conditions and under an alternating light-dark regime (12h :12h). Thirty or forty batches of seeds (n = 4) were placed on filter paper in Petri dishes and kept permanentlymoist with de-ionized water. All germinated seeds (radicula being visible) were counted everytwo to three days. The experiments lasted 45 days and, after each experiment, the remaining seeds weretested for viability.In general, the germination percentage and velocity of the investigated species was highest under warmtemperature conditions, which corresponds with the optimum development period in any year. However,with the exception of Berteroa incana, germination in the year of harvest was surprisingly low. Theseeds of Berteroa incana were not dormant and germinated equally well after harvest and after hibernation.Berteroa incana belongs to the transient seed bank type. The dormancy of Camelina microcarpa,Lepidium ruderale and Microrrhinum minus was broken after hibernation, whereas Medicago lupulina,Odontites vulgaris, Thlaspi arvense and Trifolium arvense remained dormant. The first three speciesgerminated between 50 and 94 % at 32/20 °C in the second year and built up a short-term persistent seedbank. Germination of the four latter species was very low (approx. 40 % or lower), and after hibernation,their dormancy was not significantly broken, rendering their seed bank of the long-term persistence.Key words: Germination, dormancy, natural stratification, seed bank type, viabilityDie Hercynia publiziert Originalbeiträge mit dem Schwerpunkt Ökologie (mit ihren vielseitigen Aspekten der Biodiversität), Botanik, Zoologie, Geologie und Geografie, den anwendungsorientierten Bereichen des Natur- und Umweltschutzes, sowie der Land- und Forstwirtschaft
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Zur Keimungsbiologie acht ausgewählter ephemerer Xerothermrasenarten
No full textPartzsch, M.: Germination biology of eight selected ephemeral xerothermic grassland species. – Hercynia N.F. 42 (2009): 93–110.The germination behaviour of plants is strongly related to the environmental conditions and the biology and life span of the species involved. In the natural-near xerothermic vegetation of the porphyry landscape around Halle, Germany (Saxony-Anhalt), we can find plant species with a very narrow seasonal dynamic. These are ephemeral plants which are annual and survive long time of the year as seeds in the soil. They can germinate in very early spring or in summer. Other species germinate in autumn und overcome winter as seedlings or juvenile individuals. Both types can be also in combination. For this study our goal was to find out whether the different types of therophytes are characterized by the same germination pattern, or if they show differences depending on their life types. For the consequent comparative studies on germination temperature, percentage germination, velocity, dormancy and viability we selected the following eight species: Cerastium semidecandrum, Erophila verna, Gypsophila muralis, Myosotis ramosissima, M. stricta, Saxifraga tridactylites, Spergula morisonii and Veronica verna.The germination experiments were carried out under varying light-dark-regimes (12/12 hrs at 8/4 °C, 20/10 °C, and 32/20 °C). The first experiment was started ca. 6 weeks after harvest. The rest of the seeds was burrowed under field conditions outdoors and exposed to a natural stratification. The second germination experiment was initiated after hibernation in the following spring. The viability of seeds was tested before and after the 1st and 2nd round of experiments. Results show that there was no complete dormancy in any of the species; a certain proportion of seeds always germinated under all conditions. For C. semidecandrum, E. verna, G. muralis, S. tridactylites and S. morisonii germination percentage and velocity was lowest in the fruiting year while after hibernation it was significantly higher and faster. In the case of M. ramosissima, M. stricta and V. verna, germination was highest in autumn while after hibernation only a small proportion of seeds germinated. The germination behaviour of the eight target species is related to the life span of the species: C. semidecandrum, E. verna, S. tridactylites and S. morisonii are summer annual as well as annual hibernating species. A small proportion of seeds already germinated in the year of harvesting; after hibernation they germinated very quickly with between 85 and 100 % germination at optimal temperature/light-conditions of 20/10 °C. In accordance with Jäger & Werner (2005), M. ramosissima, M. stricta and V. verna are just annual hibernating species. However, in our study they showed highest germination success in autumn while in the spring germination was minimal and slow, and only under cold conditions (8/4 °C). G. muralis is summer annual, but germination in the year of harvesting was low under all three temperature/ light-conditions. After hibernation, half of the seeds germinated quickly under cold and medium conditions. Also, under warm conditions (32/20 °C) she was relatively successful. The very low seed size of the eight species argued for a long-term persistent diaspore bank. Caused to the germination and dormancy pattern it was estimated differently. The results show, that C. semidecandrum, E. verna, S. tridactylites and S. morisonii almost completely germinate after hibernation, which would assign these species to the short-term persistent diaspore bank type. The low germination and the high seed viability after hibernation in M. ramosissima and M. stricta may suggest a long-term persistent diaspore bank type. However, V. verna developed a transient and G. muralis a short-term till long-term persistent seed bank.Die Hercynia publiziert Originalbeiträge mit dem Schwerpunkt Ökologie (mit ihren vielseitigen Aspekten der Biodiversität), Botanik, Zoologie, Geologie und Geografie, den anwendungsorientierten Bereichen des Natur- und Umweltschutzes, sowie der Land- und Forstwirtschaft
Zur Keimungsbiologie acht ausgewählter Xerothermrasenarten: Teil 3: Asteraceae
No full textPartzsch, M.: Germination biology of xerothermic grassland species - Part 3: Asteraceae. - HercyniaN. F. 44 (2011): 211 – 227.Currently, restoration of species-rich dry grassland communities is in focus of vegetation ecology. Theexperimental approaches are seed addition and hay transfer. A requirement for the prediction of successis a good knowledge of the germination biology of the introduced species. In this study eight xerothermicspecies of the family Asteraceae were investigated: Achillea nobilis, A. pannonica, Centaureajacea subsp. angustifolia, C. scabiosa subsp. scabiosa, Hieracium pilosella, H. umbellatum, Tanacetumcorymbosum and Taraxacum laevigatum.The germination experiments were carried out under three temperature-light regimes (8 / 4 °C, 20 /10 °C, 32 / 20 °C; 12 h light : 12 h darkness; 45 days). The collected seeds were divided in two parts.The first experiment was carried out in the year of harvest. The other diaspores were buried in soil fromNovember till March, to ensure hibernation until the next experimental phase in following spring. Seedviability was tested before and after the experiments.Results show that seeds of all species are not fully dormant. Seeds of Achillea nobilis und Taraxacumlaevigatum germinated completely in the year of harvest and also after hibernation. But only a half ortwo-thirds of seeds of the other species germinated. This indicates an asynchronous germination andmeans that, even under favourable conditions, only a proportion of seeds germinate in a certain time.Achillea nobilis showed an optimal germination at 20 / 10 °C, and Hieracium umbellatum at 32 / 20 °C,while Achillea pannonica, Centaurea scabiosa, Hieracium pilosella and Tanacetum corymbosum germinatedin a broad range of temperatures between 20 / 10 °C and 32 / 20 °C. Taraxacum laevigatum,however, germinated between 8 / 4 °C and 20 / 10 °C. Centaurea jacea and Hieracium pilosella showedan optimal germination at 20 / 10 °C and 32 / 20 °C, but also relatively high germination rates at 8 / 4 °C.Germination of Centaurea jacea and Taraxacum laevigatum was not significantly affected by naturalcold stratification. The other species showed a change in temperature sensitivity. Because of the earlystart of germination under warm and hot conditions, germination velocity is very high. After hibernationthe germination started few days earlier.Results regarding the germination behaviour and seed viability allow to assign the species to two typesof the diaspore bank: (1) transient: Achillea nobilis and Taraxacum laevigatum and (2) short-term persistent:Achillea pannonica, Centaurea jacea, C. scabiosa, Hieracium pilosella, H. umbellatum andTanacetum corymbosum.Results suggest that the investigated species are well suitable for restoration of species-rich dry grasslandcommunities.Die Hercynia publiziert Originalbeiträge mit dem Schwerpunkt Ökologie (mit ihren vielseitigen Aspekten der Biodiversität), Botanik, Zoologie, Geologie und Geografie, den anwendungsorientierten Bereichen des Natur- und Umweltschutzes, sowie der Land- und Forstwirtschaft
Zur Keimungsbiologie von zwölf ausgewählten Ruderal-, Wiesen- und Xerothermrasenarten - Teil 5: Apiaceae
No full textPartzsch, M.: Germination biology of twelve ruderal, meadow and xerothermic grassland species - Part 5: Apiaceae. - Hercynia N. F. 45 (2012): 173 – 192.
With the present study the series on investigation of germination biology of species from xerothermic and mesothermic grasslands and ruderally influenced habitats should be proceeding because germination is very important for establishment of species and the knowledge of this process is necessary to evaluate the success of restoration of species rich grasslands especially after disturbance. The following twelve species of the family Apiaceae were investigated: Bupleurum falcatum, Cervaria rivini, Conium maculatum, Daucus carota, Falcaria vulgaris, Heracleum sphondylium, Pastinaca sativa, Peucedanum oreoselinum, Pimpinella saxifraga, Seseli annuum, S. hippomarathrum, Torilis japonica.The germination experiments were carried out under three temperature-light regimes (8 / 4 °C, 20 / 10 °C, 32 / 20 °C; 12 h light : 12 h darkness; 45 days), simulating climate conditions in spring, summer and autumn. The collected diaspores were divided in two parts. Germination experiment of the first part was carried out in the year of harvest. The second part of diaspores was buried in soil from November till March, to ensure hibernation until the next experimental phase in following spring. Diaspore viability was tested before and after the experiments.The results show, that Bupleurum falcatum, Cervaria rivini, Conium maculatum, Falcaria vulgaris, Heracleum sphondylium and Pastinaca sativa germinated not or very low, Pimpinella saxifraga, Seseli annuum and S. hippomarathrum germinated between 30 and 50 % and Daucus carota, Peucedanum oreoselinum and Torilis japonica germinated with ca. 70 % in the year of harvest. Peucedanum oreoselinum, Pimpinella saxifraga, Seseli annuum and S. hippomarathrum showed optimal germination under warm conditions, and Daucus carota and Torilis japonica under hot conditions. Germination strongly increased in Conium maculatum, Daucus carota, Heracleum sphondylium, Peucedanum oreoselinum and Torilis japonica in a broad temperature range after hibernation, especially under cold conditions. This suggests a morphological or morpho-physiological dormancy. It seems that the other species have a much deeper dormancy because the germination was not promoted after hibernation. In general, the natural cold-stratification accelerated germination. Concerning the seed bank type, Conium maculatum, Daucus carota, Heracleum sphondylium, Peucedanum oreoselinum and Torilis japonica belong to the short-term persistent type and the other species to the long-term persistent type. Clear relations between life history and habitat preference and the germination behaviour of the species were not found.Results suggest that it needs long-term investigation for evaluation of restoration success on grasslands by the use of species of the family Apiaceae.Die Hercynia publiziert Originalbeiträge mit dem Schwerpunkt Ökologie (mit ihren vielseitigen Aspekten der Biodiversität), Botanik, Zoologie, Geologie und Geografie, den anwendungsorientierten Bereichen des Natur- und Umweltschutzes, sowie der Land- und Forstwirtschaft
- …
