Witt, Annette

[["dc.bibliographiccitation.artnumber","e1002438"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","PLoS Computational Biology"],["dc.bibliographiccitation.volume","8"],["dc.contributor.author","Battaglia, Demian"],["dc.contributor.author","Witt, Annette"],["dc.contributor.author","Wolf, Fred"],["dc.contributor.author","Geisel, Theo"],["dc.date.accessioned","2017-09-07T11:46:13Z"],["dc.date.available","2017-09-07T11:46:13Z"],["dc.date.issued","2012"],["dc.description.abstract","Anatomic connections between brain areas affect information flow between neuronal circuits and the synchronization of neuronal activity. However, such structural connectivity does not coincide with effective connectivity (or, more precisely, causal connectivity), related to the elusive question “Which areas cause the present activity of which others?”. Effective connectivity is directed and depends flexibly on contexts and tasks. Here we show that dynamic effective connectivity can emerge from transitions in the collective organization of coherent neural activity. Integrating simulation and semi-analytic approaches, we study mesoscale network motifs of interacting cortical areas, modeled as large random networks of spiking neurons or as simple rate units. Through a causal analysis of time-series of model neural activity, we show that different dynamical states generated by a same structural connectivity motif correspond to distinct effective connectivity motifs. Such effective motifs can display a dominant directionality, due to spontaneous symmetry breaking and effective entrainment between local brain rhythms, although all connections in the considered structural motifs are reciprocal. We show then that transitions between effective connectivity configurations (like, for instance, reversal in the direction of inter-areal interactions) can be triggered reliably by brief perturbation inputs, properly timed with respect to an ongoing local oscillation, without the need for plastic synaptic changes. Finally, we analyze how the information encoded in spiking patterns of a local neuronal population is propagated across a fixed structural connectivity motif, demonstrating that changes in the active effective connectivity regulate both the efficiency and the directionality of information transfer. Previous studies stressed the role played by coherent oscillations in establishing efficient communication between distant areas. Going beyond these early proposals, we advance here that dynamic interactions between brain rhythms provide as well the basis for the self-organized control of this “communication-through-coherence”, making thus possible a fast “on-demand” reconfiguration of global information routing modalities."],["dc.identifier.doi","10.1371/journal.pcbi.1002438"],["dc.identifier.gro","3151853"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/7868"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8682"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.relation.issn","1553-7358"],["dc.rights","CC BY 2.5"],["dc.rights.uri","https://creativecommons.org/licenses/by/2.5"],["dc.title","Dynamic Effective Connectivity of Inter-Areal Brain Circuits"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.journal","Frontiers in Neural Circuits"],["dc.bibliographiccitation.volume","7"],["dc.contributor.author","Witt, Annette"],["dc.contributor.author","Palmigiano, Agostina"],["dc.contributor.author","Neef, Andreas"],["dc.contributor.author","El Hady, Ahmed"],["dc.contributor.author","Wolf, Fred"],["dc.contributor.author","Battaglia, Demian"],["dc.date.accessioned","2017-09-07T11:45:38Z"],["dc.date.available","2017-09-07T11:45:38Z"],["dc.date.issued","2013"],["dc.description.abstract","Dynamic oscillatory coherence is believed to play a central role in flexible communication between brain circuits. To test this communication-through-coherence hypothesis, experimental protocols that allow a reliable control of phase-relations between neuronal populations are needed. In this modeling study, we explore the potential of closed-loop optogenetic stimulation for the control of functional interactions mediated by oscillatory coherence. The theory of non-linear oscillators predicts that the efficacy of local stimulation will depend not only on the stimulation intensity but also on its timing relative to the ongoing oscillation in the target area. Induced phase-shifts are expected to be stronger when the stimulation is applied within specific narrow phase intervals. Conversely, stimulations with the same or even stronger intensity are less effective when timed randomly. Stimulation should thus be properly phased with respect to ongoing oscillations (in order to optimally perturb them) and the timing of the stimulation onset must be determined by a real-time phase analysis of simultaneously recorded local field potentials (LFPs). Here, we introduce an electrophysiologically calibrated model of Channelrhodopsin 2 (ChR2)-induced photocurrents, based on fits holding over two decades of light intensity. Through simulations of a neural population which undergoes coherent gamma oscillations—either spontaneously or as an effect of continuous optogenetic driving—we show that precisely-timed photostimulation pulses can be used to shift the phase of oscillation, even at transduction rates smaller than 25%. We consider then a canonic circuit with two inter-connected neural populations oscillating with gamma frequency in a phase-locked manner. We demonstrate that photostimulation pulses applied locally to a single population can induce, if precisely phased, a lasting reorganization of the phase-locking pattern and hence modify functional interactions between the two populations."],["dc.identifier.doi","10.3389/fncir.2013.00049"],["dc.identifier.fs","599401"],["dc.identifier.gro","3151827"],["dc.identifier.pmid","23616748"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10678"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8657"],["dc.language.iso","en"],["dc.notes","Financial support by the German Federal Ministry of Education and Research (BMBF) via the Bernstein Center for Computational Neuroscience—Göttingen (01GQ1005B, 01GQ0430, 01GQ07113), the Bernstein Focus Neurotechnology—Göttingen (01GQ0811) and the Bernstein Focus Visual Learning (01GQ0921, 01GQ0922), the German Israel Research Foundation and the VolkswagenStiftung (ZN2632) and the Deutsche Forschungsgemeinschaft through CRC-889 (906-17.1/2006)."],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.relation.issn","1662-5110"],["dc.relation.orgunit","Fakultät für Physik"],["dc.subject.mesh","Action Potentials"],["dc.subject.mesh","Biological Clocks"],["dc.subject.mesh","Computational Biology"],["dc.subject.mesh","HEK293 Cells"],["dc.subject.mesh","Humans"],["dc.subject.mesh","Neural Networks (Computer)"],["dc.subject.mesh","Optogenetics"],["dc.subject.mesh","Photic Stimulation"],["dc.subject.mesh","Random Allocation"],["dc.subject.mesh","Time Factors"],["dc.title","Controlling the oscillation phase through precisely timed closed-loop optogenetic stimulation: a computational study"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","093942"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Chaos: An Interdisciplinary Journal of Nonlinear Science"],["dc.bibliographiccitation.volume","27"],["dc.contributor.author","Witt, Annette"],["dc.contributor.author","Ehlers, Frithjof"],["dc.contributor.author","Luther, Stefan"],["dc.date.accessioned","2020-12-10T18:12:37Z"],["dc.date.available","2020-12-10T18:12:37Z"],["dc.date.issued","2017"],["dc.identifier.doi","10.1063/1.5003249"],["dc.identifier.eissn","1089-7682"],["dc.identifier.issn","1054-1500"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/74439"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Extremes of fractional noises: A model for the timings of arrhythmic heart beats in post-infarction patients"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","e26457"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","PLoS ONE"],["dc.bibliographiccitation.volume","6"],["dc.contributor.author","Hennig, Holger"],["dc.contributor.author","Fleischmann, Ragnar"],["dc.contributor.author","Fredebohm, Anneke"],["dc.contributor.author","Hagmayer, York"],["dc.contributor.author","Nagler, Jan"],["dc.contributor.author","Witt, Annette"],["dc.contributor.author","Theis, Fabian J."],["dc.contributor.author","Geisel, Theo"],["dc.date.accessioned","2018-11-07T08:50:38Z"],["dc.date.available","2018-11-07T08:50:38Z"],["dc.date.issued","2011"],["dc.description.abstract","Although human musical performances represent one of the most valuable achievements of mankind, the best musicians perform imperfectly. Musical rhythms are not entirely accurate and thus inevitably deviate from the ideal beat pattern. Nevertheless, computer generated perfect beat patterns are frequently devalued by listeners due to a perceived lack of human touch. Professional audio editing software therefore offers a humanizing feature which artificially generates rhythmic fluctuations. However, the built-in humanizing units are essentially random number generators producing only simple uncorrelated fluctuations. Here, for the first time, we establish long-range fluctuations as an inevitable natural companion of both simple and complex human rhythmic performances. Moreover, we demonstrate that listeners strongly prefer long-range correlated fluctuations in musical rhythms. Thus, the favorable fluctuation type for humanizing interbeat intervals coincides with the one generically inherent in human musical performances."],["dc.identifier.doi","10.1371/journal.pone.0026457"],["dc.identifier.isi","000296519600019"],["dc.identifier.pmid","22046289"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/8345"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/21739"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1932-6203"],["dc.rights","CC BY 2.5"],["dc.rights.uri","https://creativecommons.org/licenses/by/2.5"],["dc.title","The Nature and Perception of Fluctuations in Human Musical Rhythms"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","5257"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Optics Express"],["dc.bibliographiccitation.volume","28"],["dc.contributor.author","de Beurs, A. C. C."],["dc.contributor.author","Liu, X."],["dc.contributor.author","Jansen, G. S. M."],["dc.contributor.author","Konijnenberg, A. P."],["dc.contributor.author","Coene, W. M. J."],["dc.contributor.author","Eikema, K. S. E."],["dc.contributor.author","Witte, S."],["dc.creator.author","A. C. C. de Beurs"],["dc.creator.author","X. Liu"],["dc.creator.author","G. S. M. Jansen"],["dc.creator.author","A. P. Konijnenberg"],["dc.creator.author","W. M. J. Coene"],["dc.creator.author","K. S. E. Eikema"],["dc.creator.author","S. Witte"],["dc.date.accessioned","2022-10-19T09:52:38Z"],["dc.date.available","2022-10-19T09:52:38Z"],["dc.date.issued","2020"],["dc.identifier.doi","10.1364/OE.380056"],["dc.identifier.eissn","1094-4087"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/116336"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Extreme ultraviolet lensless imaging without object support through rotational diversity in diffractive shearing interferometry"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Bulletin of the American Physical Society"],["dc.bibliographiccitation.volume","58"],["dc.contributor.author","Witt, Annette"],["dc.contributor.author","Battaglia, Demian"],["dc.contributor.author","Gail, Alexander"],["dc.date.accessioned","2018-02-26T14:17:17Z"],["dc.date.available","2018-02-26T14:17:17Z"],["dc.date.issued","2013"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/12627"],["dc.language.iso","en"],["dc.notes","https://meetings.aps.org/Meeting/MAR13/Event/190986"],["dc.notes.status","fcwi"],["dc.relation.conference","American Physical Society March Meeting"],["dc.relation.eventend","2013-03-22"],["dc.relation.eventlocation","Baltimore, Md"],["dc.relation.eventstart","2013-03-18"],["dc.title","Paradoxical Behavior of Granger Causality"],["dc.type","conference_abstract"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1087.2"],["dc.bibliographiccitation.issue","Suppl 1"],["dc.bibliographiccitation.journal","Annals of the Rheumatic Diseases"],["dc.bibliographiccitation.lastpage","1088"],["dc.bibliographiccitation.volume","81"],["dc.contributor.author","Hoeper, J. R."],["dc.contributor.author","Iliadis, I."],["dc.contributor.author","Richter, M."],["dc.contributor.author","Meyer, S. E."],["dc.contributor.author","Kahl, K."],["dc.contributor.author","Witte, T."],["dc.contributor.author","Hoeper, K."],["dc.contributor.author","Meyer-Olson, D."],["dc.date.accessioned","2022-11-01T10:17:07Z"],["dc.date.available","2022-11-01T10:17:07Z"],["dc.date.issued","2022"],["dc.description.abstract","Background\r\n Disease flares of rheumatoid arthritis (RA) are important stressors for patients (pts) who may use coping for disease management. Some coping styles are thought to be beneficial and may help to improve disease outcome whereas others are thought to be harmful.\r\n \r\n \r\n Objectives\r\n We investigate the frequency and intensity of different coping styles in pts with an acute flare of seropositive RA and its impact on disease outcomes after 12 month of therapy.\r\n \r\n \r\n Methods\r\n Coping was analysed with the Brief-COPE (1) using a 4 point Likert scale in 222 pts participating in the ERFASS study (2). Coping styles were analysed by confirmatory and exploratory factor analysis (CFA, EFA). Disease activity was measured via DAS28 (CRP), depression and/or anxiety using Hospital Anxiety and Depression Scale (HADS) and Patient Health Questionnaire 9 (PHQ-9). Repeated measures ANOVA was used to identify the effect of different coping strategies on disease activity and Spearman-Rho to identify correlations.\r\n \r\n \r\n Results\r\n Factor analysis revealed five dominant coping styles (problem oriented, emotion oriented, dysfunctional, religion, alcohol/drugs) which were consistent during 6 and 12 months follow up. When analysing the relative intensity of each coping strategy over time there was no significant change during treatment (Table 1). The usage of only a single coping style at baseline (“I am doing this a medium amount” or “a lot”) was reported by 70 pts (31,5%). 65 pts (29,3%) reported the use of 2 coping styles simultaneously, 25 pts (11,3%) 3 coping styles and 4 pts (1,8%) four coping styles. Problem oriented coping was used by 125 pts (56,3%), emotional coping by 97 pts (43,7%), dysfunctional coping by 41 pts (18,5%), religion by 24 pts (10,8%) and alcohol/drugs by only 4 pts (1,8%). 58 pts (26,1%) reported not to use any of the coping styles (“I am doing this not at all” or “only a little bit”) and these pts had a lower DAS28 during the course of the study (p=0.036) as compared to pts who use one or more coping strategies. When analysing the group with high disease activity (DAS28 >5.1) at baseline (n=60), pts with medium or high dysfunctional coping had a significantly higher disease activity after 12 months as compared to those with no or little dysfunctional coping (U = 187,00, Z = -2.025, p = 0.043) (Figure 1). The other coping styles did not significantly predict the outcome of disease activity. We observed a strong correlation between dysfunctional coping and depression (PHQ9 r = 0.590; HADS depression r = 0.569) as well as anxiety (HADS anxiety r = 0.639) but not for the other coping strategies at baseline.\r\n \r\n Figure 1.\r\n \r\n \r\n \r\n Table 1.\r\n \r\n Development of disease activity (DAS28) and coping strategies over time\r\n \r\n \r\n \r\n \r\n \r\n Time\r\n \r\n \r\n \r\n Baseline mean (SD)\r\n Month 6 mean (SD)\r\n Month 12 mean (SD)\r\n \r\n \r\n \r\n \r\n DAS28\r\n 4.32 (1.14)\r\n 2.79 (1.23)\r\n 2.47 (1.05)\r\n \r\n \r\n Problem oriented\r\n 53.10 (14.93)\r\n 49.69 (14.10)\r\n 47.43 (14.00)\r\n \r\n \r\n Emotion oriented\r\n 49.94 (13.00)\r\n 50.73 (12.76)\r\n 50.46 (13.45)\r\n \r\n \r\n Dysfunctional\r\n 40.25 (14.59)\r\n 36.44 (11.76)\r\n 36.00 (12.26)\r\n \r\n \r\n Religion\r\n 36.15 (18.30)\r\n 35.53 (17.02)\r\n 34.68 (16.64)\r\n \r\n \r\n Alcohol / Drugs\r\n 27.03 (7.81)\r\n 27.15 (8.75)\r\n 26.53 (6.07)\r\n \r\n \r\n \r\n \r\n \r\n \r\n Conclusion\r\n Different ways of coping may be used simultaneously during an acute flare of seropositive RA. In pts with high disease activity dysfunctional coping is the only coping strategy predicting a worse disease outcome after 12 months and dysfunctional coping correlates with depression and anxiety.\r\n \r\n \r\n References\r\n [1]Carver CS (1997) You want to measure coping but your protocol’s too long: consider the brief COPE. Int J Behav Med 4(1):92–100.\r\n [2]Hoeper JR, Zeidler J, Meyer SE, et al. Effect of nurse-led care on outcomes in patients with ACPA/RF-positive rheumatoid arthritis with active disease undergoing treat-to-target: a multicentre randomised controlled trial. RMD Open 2021\r\n \r\n \r\n Disclosure of Interests\r\n Juliana Rachel Hoeper: None declared, Ioana Iliadis: None declared, Marianne Richter: None declared, Sara Eileen Meyer: None declared, Kai Kahl: None declared, Torsten Witte: None declared, Kirsten Hoeper Speakers bureau: Abbvie, Novartis, Galapagos, Sandoz Hexal, Chugai, Lilly, Consultant of: Abbvie, Novartis, Galapagos, Sandoz Hexal, Dirk Meyer-Olson Speakers bureau: Bristol Myers Squibb, Celltrion, Chugai, Fresenius Kabi, Galapagos, Lilly, Sandoz Hexal\r\n , Consultant of: Abbvie, Amgen, Astra Zeneca, Biogen, Novartis, Viatris"],["dc.identifier.doi","10.1136/annrheumdis-2022-eular.3743"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/116738"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-605"],["dc.relation.eissn","1468-2060"],["dc.relation.issn","0003-4967"],["dc.title","POS1483-HPR Dysfunctional Coping Correlates with Depression and Anxiety and Predicts Worse Outcome in Patients with a High Disease Activity in Rheumatoid Arthritis"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","126"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Pediatric Research"],["dc.bibliographiccitation.lastpage","133"],["dc.bibliographiccitation.volume","55"],["dc.contributor.author","Roth, C."],["dc.contributor.author","Hegemann, F."],["dc.contributor.author","Hildebrandt, J."],["dc.contributor.author","Balzer, I."],["dc.contributor.author","Witt, Annette"],["dc.contributor.author","Wuttke, Wolfgang"],["dc.contributor.author","Jarry, Hubertus"],["dc.date.accessioned","2018-11-07T10:53:01Z"],["dc.date.available","2018-11-07T10:53:01Z"],["dc.date.issued","2004"],["dc.description.abstract","Central precocious puberty is commonly treated by gonadotropin releasing hormone (GnRH) agonists. To compare modes of action and effectiveness of GnRH analogues and assess treatment combinations of agonistic (triptorelin) and antagonistic (cetrorelix acetate) GnRH analogues with established treatment, we used prepubertal 31-d-old ovariectomized female rats. Strongest inhibition of LH and FSH occurred after 2-d treatment with antagonist alone (LH 0.08 +/- 0.02 versus 3.2 +/- 0.56 ng/mL in controls; FSH 10.8 +/- 2.8 versus 44.2 +/- 5.0 ng/mL in controls, p < 0.001). Combined agonist/antagonist was second most effective of the treatments (after 5 d treatment, LH 0.52 +/- 0.15 versus 4.9 +/- 1.1 ng/mL in controls; p < 0.01). Pituitary gonadotropin subunit LHbeta mRNA levels were inhibited in all groups except controls, but pituitary GnRH receptor mRNA was stimulated by agonist yet unaffected by combined analogues. Explanted ovaries were incubated with either analogue, both 10(-6) M. After 4 h, GnRH receptor mRNA levels were significantly reduced by antagonist. but not agonist. To verify puberty-inhibiting effects of GnRH analogues, we used 26-d-old female rats with androgen-induced precocious puberty after injecting subcutaneously single 300 mug danazol on postnatal d 5. Single application of cetrorelix depot (cetrorelix embonate) reduced serum estradiol levels and pituitary LHbeta expression; GnRH receptor mRNA levels were down-regulated in the pituitary and ovary (p < 0.05). In androgen-induced precocious puberty model, single injection of antagonist effectively arrests premature hormonal activation and down-regulates pituitary and ovarian GnRH receptors. We conclude that GnRH analogue combination and especially antagonist alone treatment most directly suppress gonadotropin levels. This implies that early treatment gonadotropin flare-up associated with agonist treatment is avoidable."],["dc.identifier.doi","10.1203/01.PDR.0000100463.84334.3F"],["dc.identifier.isi","000187502400018"],["dc.identifier.pmid","14605254"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49254"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Int Pediatric Research Foundation, Inc"],["dc.relation.issn","0031-3998"],["dc.title","Pituitary and gonadal effects of GnRH (gonadotropin releasing hormone) analogues in two peripubertal female rat models"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","555"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Transactions of the ASABE"],["dc.bibliographiccitation.lastpage","563"],["dc.bibliographiccitation.volume","57"],["dc.contributor.author","Steinmeier, U."],["dc.contributor.author","Neudecker, M."],["dc.contributor.author","Witt, Annette"],["dc.contributor.author","von Hoersten, Dieter"],["dc.contributor.author","Schroeter, M."],["dc.date.accessioned","2018-11-07T09:46:14Z"],["dc.date.available","2018-11-07T09:46:14Z"],["dc.date.issued","2014"],["dc.description.abstract","The ability to mark bulk goods from different origins with RFID markers is of industrial interest, as such a method would improve the traceability of, e. g., cereals. However, due to a number of open technical questions, this method has not been utilized on a larger scale yet. This article studies the amount of segregation occurring between RFID markers, which are simulated as grain-sized plastic capsules, and marked wheat using two different setups. This segregation could occur during handling and transport due to the slightly different physical properties of the markers and the grains; it would then lead to erroneous results during subsequent quantitative analysis. In the first experiment, two samples of wheat, one marked with RFID dummies, were discharged in several steps from a test silo. A comparison of the marker concentration in the samples with the amount of associated wheat showed no discernible segregation. An additional statistical analysis allowed us to establish a relationship between the marker concentration and the error margin. In the second experiment, a mixture of wheat and markers was vertically shaken in a container, mimicking transport of wheat in large vessels. The position of the markers inside the container was determined by three-dimensional scans using x-ray tomography. We found that shaking induced some segregation due to sidewall-driven convection rolls, which indicated that the simulated markers were not optimally matched to the wheat grains."],["dc.description.sponsorship","State of Lower Saxony"],["dc.identifier.isi","000335896600017"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/34827"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Soc Agricultural & Biological Engineers"],["dc.relation.issn","2151-0040"],["dc.relation.issn","2151-0032"],["dc.title","SEGREGATION OF SIMULATED RFID MARKERS DURING HANDLING AND TRANSPORT OF WHEAT"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","e0125785"],["dc.bibliographiccitation.firstpage","1"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","PLOS ONE"],["dc.bibliographiccitation.lastpage","16"],["dc.bibliographiccitation.volume","10"],["dc.contributor.author","Wadewitz, P."],["dc.contributor.author","Hammerschmidt, K."],["dc.contributor.author","Battaglia, D."],["dc.contributor.author","Witt, A."],["dc.contributor.author","Wolf, F."],["dc.contributor.author","Fischer, J."],["dc.date.accessioned","2017-09-07T11:45:38Z"],["dc.date.available","2017-09-07T11:45:38Z"],["dc.date.issued","2015"],["dc.description.abstract","To understand the proximate and ultimate causes that shape acoustic communication in animals, objective characterizations of the vocal repertoire of a given species are critical, as they provide the foundation for comparative analyses among individuals, populations and taxa. Progress in this field has been hampered by a lack of standard in methodology, however. One problem is that researchers may settle on different variables to characterize the calls, which may impact on the classification of calls. More important, there is no agreement how to best characterize the overall structure of the repertoire in terms of the amount of gradation within and between call types. Here, we address these challenges by examining 912 calls recorded from wild chacma baboons (Papio ursinus). We extracted 118 acoustic variables from spectrograms, from which we constructed different sets of acoustic features, containing 9, 38, and 118 variables; as well 19 factors derived from principal component analysis. We compared and validated the resulting classifications of k-means and hierarchical clustering. Datasets with a higher number of acoustic features lead to better clustering results than datasets with only a few features. The use of factors in the cluster analysis resulted in an extremely poor resolution of emerging call types. Another important finding is that none of the applied clustering methods gave strong support to a specific cluster solution. Instead, the cluster analysis revealed that within distinct call types, subtypes may exist. Because hard clustering methods are not well suited to capture such gradation within call types, we applied a fuzzy clustering algorithm. We found that this algorithm provides a detailed and quantitative description of the gradation within and between chacma baboon call types. In conclusion, we suggest that fuzzy clustering should be used in future studies to analyze the graded structure of vocal repertoires. Moreover, the use of factor analyses to reduce the number of acoustic variables should be discouraged."],["dc.identifier.doi","10.1371/journal.pone.0125785"],["dc.identifier.gro","3151834"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/11824"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8660"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","public"],["dc.notes.submitter","final"],["dc.relation.issn","1932-6203"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","Characterizing Vocal Repertoires—Hard vs. Soft Classification Approaches"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]