67,633 research outputs found
Cymatosirella taylorii Dabek & Witkowski 2013, sp. nov.
No full text<i>Cymatosirella taylorii</i> Dąbek & Witkowski <i>sp. nov.</i> (Figs 44–51 [LM], Figs 52–58 [SEM]) <p>Frustules rectangular in girdle view with undulated outline. Valves lanceolate to elliptical, 4–13 µm long and 1–4 µm wide. Central part of valve face and apices elevated. Valve surface areolated, with ca. 50 areolae in 10 µm. Areolae distributed over the whole valve face.</p> <p> <b>Type:</b> — SOUTH AFRICA. Western Cape Province: eastern part of Langebaan Lagoon, Saldanha Bay, sandy sediment from the intertidal sandbank (33°6’788’’S; 18°2’631’’E) collected on 19 th February 2011 by Dąbek, Witkowski & Archibald (SZCZ 17582, holotype!).</p> <p> <b>Habitat:</b> —The eastern part of Langebaan Lagoon is a shallow, sandy tidal pool. High and low tide occur twice a day. Sea surface water temperature exceeds 18° C</p> <p> <b>Etymology:</b> —Named after and dedicated to our friend and prominent South African diatomologist Dr. Jonathan Taylor (North-West University, Potchefstroom, South Africa).</p> <p> <b>Observations:</b> —The frustules are rectangular in girdle view with an undulated outline (Figs 44–47, 52). Cells are predominantly solitary, but occasionally two cells were found joined together (Fig. 44). The girdle is broad, and composed of numerous bands bearing one row of fine puncta (Fig. 52). The valves are lanceolate to elliptical, 4–13 µm long and 1–4 µm wide (Figs 48–51, 53). The central part of the valve face and apices are elevated (Figs 54, 56). The valve surface is strongly ornamented with areolae, ca. 50 in 10 µm (Figs 53–56). Near the central elevation, areolae are randomly distributed; further towards the apices they are arranged in longitudinal rows (Figs 53, 55, 56). Occlusions have not been observed. Each valve bears two ocelluli, composed of 7–10 porelli, with 1–2 central ones (Figs 57, 58). The ocelluli are surrounded by a hyaline ring of silica (Figs 53, 55, 57). No areolae occur near the ocelluli (Figs 53, 57). Spines were observed only rarely. Processes, pili, fascia nor pseudosepta have not been observed.</p> <p> <b>Ecology and geography:</b> — <i>Cymatosirella taylorii</i> has been found in only one sandy sample (SZCZ 17582, the holotype) from an intertidal sandbank in the eastern part of the Langebaan Lagoon. Only a dozen valves have been found. This species most probably belongs to the epipsammon.</p>Published as part of <i>Dąbek, Przemysław, Sabbe, Koen, Witkowski, Andrzej, Archibald, Colin, Kurzydłowski, Krzyszof J. & Zgłobicka, Izabela, 2013, Cymatosirella Dąbek, Witkowski & Sabbe gen. nov., a new marine benthic diatom genus (Bacillariophyta) belonging to the family Cymatosiraceae, pp. 42-56 in Phytotaxa 121 (1)</i> on page 50, DOI: 10.11646/phytotaxa.121.1.2, <a href="http://zenodo.org/record/5079466">http://zenodo.org/record/5079466</a>
Ultrasonic Sensor for Mobile Mini-Robots Using Pseudo-Random Codes
No full textKlahold J, Rautenberg J, Rückert U. Ultrasonic Sensor for Mobile Mini-Robots Using Pseudo-Random Codes. In: Rückert U, Sitte J, Witkowski U, eds. Proceedings of the 5th International Heinz Nixdorf Symposium: Autonomous Minirobots for Research and Edutainment (AMiRE01). Vol 97. Heinz Nixdorf Institut, Universität Paderborn; 2001: 225-232
Mining e-mail content for author identification forensics
No full textWe describe an investigation into e-mail content mining for author identification, or authorship attribution, for the purpose of forensic investigation. We focus our discussion on the ability to discriminate between authors for the case of both aggregated e-mail topics as well as across different email topics. An extended set of e-mail document features including structural characteristics and linguistic patterns were derived and, together with a Support Vector Machine learning algorithm, were used for mining the e-mail content. Experiments using a number of e-mail documents generated by different authors on a set of topics gave promising results for both aggregated and multi-topic author categorisation
Enhanced siliceous plankton productivity in response to middle Eocene warming at Southern Ocean ODP Sites 748 and 749
No full textThe Middle Eocene Climatic Optimum (MECO) is a major transient warming event that occurred at ~ 40 Ma and reversed a long-term cooling trend through the early and middle Eocene. We report the results of a high-resolution, quantitative study of siliceous microfossils at Ocean Drilling Program Sites 748 and 749 (Southern Kerguelen Plateau, Southern Ocean, ~ 58°S) across a ~ 1.4 myr interval spanning the MECO event. At both sites, a significant increase in biosiliceous sedimentation is associated with the MECO event. Rich siliceous planktonic microfossil assemblages in this interval are unusual in that they are dominated by ebridians, with radiolarians as a secondary major component. Silicoflagellates and diatoms comprise only a minor fraction of the assemblage, in contrast to siliceous microfossil assemblages that characterize modern Southern Ocean sediments. Based on our new siliceous microfossil records, we interpret two ~ 300 kyr periods of elevated nutrient availability in Southern Ocean surface waters which span the peak warming interval of the MECO and the post-MECO cooling interval. A diverse assemblage of large silicoflagellates belonging to the Dictyocha grandis plexus is linked to the rapid rise in sea-surface temperatures immediately prior to peak warmth, and a pronounced turnover is observed in both ebridian and silicoflagellate assemblages at the onset of peak warming. The interval of peak warmth is also characterized by high abundance of cosmopolitan ebridians (e.g., Ammodochium spp.) and silicoflagellates (e.g., Naviculopsis spp.), and increased abundance of tropical and subtropical diatom genera (e.g., Asterolampra and Azpeitia). These observations confirm the relative pattern of temperature change interpreted from geochemical proxy data at multiple Southern Ocean sites. Furthermore, rapid assemblage changes in both autotrophic and heterotrophic siliceous microfossil groups indicate a reorganization of Southern Ocean plankton communities in response to greenhouse warming during the MECO event
A Bluetooth Scatternet for the Khepera Robot
No full textDu JL, Witkowski U, Rückert U. A Bluetooth Scatternet for the Khepera Robot. In: 4th International Symposium on Autonomous Minirobots for Research and Edutainment (AMiRE). Buenos Aires, Argentina; 2007: 189-195.Radio-based communication plays a vital role in multi-robot systems.
Bluetooth is an energy-efficient communication technology suited for resourcelimited mini-robots such as the Khepera. However, the maximum number of nodes in a Bluetooth piconet is limited, while scatternets - networks of piconets - have not been fully specified. In this paper we present a Bluetooth scatternet using Bluetooth communication sticks developed in our research group. In our solution, bridge nodes carrying two of such Bluetooth sticks are used to interconnect piconets. Beside the developed hardware, issues such as routing as well as topology control are addressed. Finally, data rate and latency measurements are presented for the implemented solution
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
Teleworkbench: An Analysis Tool for Multi-Robotic Experiments
No full textTanoto A, Du JL, Witkowski U, Rückert U. Teleworkbench: An Analysis Tool for Multi-Robotic Experiments. In: Proceedings of the IFIP Conference on Biologically Inspired Cooperative Computing (BICC 2006), 19th World Computer Congress (WCC). Santiago, Chile; 2006.This paper presents a tool, one component of the Teleworkbench
system, for analyzing experiments in multi-robotics. The proposed
tool combines the video taken by a web cam monitoring the field
where the experiment runs and some computer generated visual objects
representing important events and information as well as robots’
behavior into one interactive video based on MPEG-4 standard. Visualization
and data summarization enables the developer to quickly grasp
a situation, whereas the possibility of scrolling through the video and
selectively activating information helps him analyzing interesting events
in depth. Because of the MPEG-4 standard used for the output video,
the analysis process can be done in a wide range of platforms. This trait
is beneficial for education and research cooperation purposes
"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
Case Report: melanoma and melanocytic nevus differentiation with reflectance confocal microscopy. [v1; ref status: indexed, http://f1000r.es/5mr]
No full textHistorically, melanoma has been typically diagnosed by naked-eye examination and confirmed with invasive biopsy. However, recently the use of reflectance confocal microscopy enables non-invasive bedside diagnosis of clinically equivocal lesions. We present a case in which reflectance confocal microscopy was used to evaluate two skin lesions in the same patient confirming the diagnosis of a melanoma and potentially avoiding invasive biopsy in the second benign melanocytic lesion. Clinicians should be aware of the availability of new non-invasive technologies that can aid in early diagnosis of malignant skin tumors and potentially reduce the number of benign lesion excisions
Author, publisher and bookseller : a tripartite synergy in Nigerian book industry
No full textThis work is about the roles of Author, Publisher and Bookseller in Book development in
Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after
which it proceeded by defining who an author, a publisher, and a bookseller is and
expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in
the emerging Information Society. Furthermore, the various constraints to book
development were identified while the paper advised on how the Book Industry can be
further promoted in Nigeria. However, the paper concluded and made recommendations
on how the Book sector can help in enhancing scholarship in the country
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