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Context Dependent Auditory Thresholds Determined by Brainstem Audiometry and Prepulse Inhibition in Mongolian Gerbils

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Open Journal of Acoustics 2012年第1期2卷 34-49页

作者： markus walter Konstantin Tziridis Sonke Ahlf Holger Schulze Experimental Otolaryngology University of Erlangen-Nuremberg Erlangen Germany

Information on hearing thresholds is not always reliable as differences in these thresholds have been described even for the same species. This may partially be due to different methods used by different labs. A frequently used approach to obtain an estimate of hearing threshold is the electrophysiological recording of auditory brainstem responses (ABR). They are usually recorded under deep anesthesia and represent the auditory evoked far-field potentials at various levels in the central auditory pathway. Alternatively, several behavioral approaches are employed. These commonly use operant or classical conditioning to determine hearing thresholds. A potential disadvantage of these methods is that any sound conditioning may in principle alter auditory perception and therefore auditory thresholds. To exclude this type of methodological bias a prepulse inhibition (PPI) paradigm can be used where an audiogram can be determined without any kind of pre-training. Here we compare the threshold estimates obtained by two different ABR and PPI measurements where stimuli are presented in different contexts, either randomly or non-randomly, to test for a possible effect of auditory sensitization. In addition we test the effect of a frequency specific acoustic trauma on the audiograms obtained with both methods. In general we find behaviorally determined audiograms to be significantly lower in absolute thresh- old compared to ABR measurements. Furthermore non-randomized presentation context of the stimuli generally results in audiograms with 10 to 15 dB lower thresholds than pseudo-randomized presentation. Finally, the amount of threshold loss induced by acoustic trauma is similar for all methods tested.

关键词： Acoustic Trauma Hearing Thresholds Auditory Processing Startle Response

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Species-specific effects of genetic diversity and species diversity of experimental communities on early tree performance

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Journal of Plant Ecology 2017年第1期10卷 252-258页

作者： Xueqin Zeng walter Durka markus Fischer Department of Community Ecology(BZF) Helmholtz Centre for Environmental Research-UFZTheodor-Lieser-Str.4Halle D-06120Germany Institute of Plant Sciences University of BernAltenbergrain 21Bern CH-3013Switzerland Kadoorie Farm and Botanic Garden Lam Kam RoadTai PoNew TerritoriesHong Kong German Centre for Integrative Biodiversity Research(iDiv) Halle-Jena-LeipzigDeutscher Platz 5eLeipzig D-04103Germany

Aims Changing biodiversity can affect ecosystem ***,the role of genetic diversity within species,relative to the one of species diversity,has hardly been *** To address the effects of both genetic diversity and species diversity during the important stage of early tree life,we used eight seed families(SF)taken from each of 12 evergreen and deciduous tree species of subtropical forest to perform a factorial *** established 264 communities of 16 trees *** community had a species diversity of either one or four species and a genetic diversity of either one,two or four SF per *** measured plant survival,growth rate,final biomass and herbivory 20 months after *** Findings Species differed from each other in biomass,growth rate,herbivory and survival(P<0.001).Deciduous species tended to have much higher biomass(P<0.1)and experienced higher herbivory(P<0.05)than evergreen *** diversity affected the performance of different species differently(species diversity by species interaction,P<0.001 for all variables but survival).Biomass differed between SF and increasing genetic diversity from one to two,and from two to four,SF per species increased biomass for some species and decreased it for others(P<0.001).Our study showed pronounced species-specific responses of early tree performance to species diversity and less pronounced responses to genetic *** species-specific responses suggest feedbacks of species diversity and genetic diversity on future species composition.

关键词： biodiversity-ecosystem functioning tree biomass herbivory survival subtropical China allometry

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Heritability of early growth traits and their plasticity in 14 woody species of Chinese subtropical forest

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Journal of Plant Ecology 2017年第1期10卷 222-231页

作者： Xueqin Zeng walter Durka Erik Welk markus Fischer UFZ-Helmholtz Centre for Environmental Research Department of Community Ecology(BZF)Theodor-Lieser-Str.4D-06120 HalleGermany Institute of Plant Sciences University of BernAltenbergrain 21CH-3013 BernSwitzerland Kadoorie Farm and Botanic Garden Lam Kam RoadTai PoNew TerritoriesHong Kong Institute of Biology Martin Luther University Halle-WittenbergAm Kirchtor 01D-06108 HalleGermany

Aims Genetic variation in plant traits represents the raw material for future adaptive *** extent can be estimated as heritability based on the performance of experimental plants of known relatedness,such as maternal half-sib seed *** there is considerable heritability information for herbaceous plants and commercially important trees,little is known for woody species of natural subtropical ***,it is open whether heritability is higher for species with r-or K-strategies,for more common species with larger distribution ranges than for rarer ones,or for populations closer to the centres of distributional *** For 14 woody species in Chinese subtropical forest,we collected 13-38 maternal seed families,assessed seed size,grew replicates of each seed family in one more and one less benign nursery environment and measured stem diameter and plant height after 7 *** findings For the different species,plants grew 1.8-8.1 times taller in the more benign *** all 14 species,variation between seed families(and thus heritability)was significant(with very few exceptions at the P<0.001 level)for seed size and for stem diameter and plant height in both ***,significant seed family by nursery interactions for stem diameter and plant height for all species(P<0.001)indicated significant heritability for plasticity in these *** regression analysis suggests that heritabilities were higher for species with higher age at reproduction and higher wood density(traits indicating a K strategy)but also for species with higher specific leaf area(a trait rather indicating an r strategy).Furthermore,heritabilities were higher for species with larger range sizes,while there was no significant relationship between heritabilities and the distance of the study area to the range margins of our study *** conclusion,the detected large heritability estimates suggest considerable potential for the evolution

关键词： heritability plant performance phenotypic plasticity subtropical forest

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Species diversity and population density affect genetic structure and gene dispersal in a subtropical understory shrub

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Journal of Plant Ecology 2012年第3期5卷 270-278页

作者： Xueqin Zeng Stefan G.Michalski markus Fischer walter Durka UFZ-Helmholtz Centre for Environmental Research Department of Community Ecology(BZF)Theodor-Lieser-Strasse 4D-06120 HalleGermany Institute of Plant Sciences University of BernAltenbergrain 21CH-3013 BernSwitzerland

Aims The dispersal of pollen and seeds is spatially restricted and may vary among plant populations because of varying biotic interactions,population histories or abiotic *** gene dispersal is spatially restricted,it will eventually result in the development of spatial genetic structure(SGS),which in turn can allow insights into gene dispersal ***,we assessed the effect of habitat characteristics like population density and community structure on small-scale SGS and estimate historical gene dispersal at different spatial *** In a set of 12 populations of the subtropical understory shrub Ardisia crenata,we assessed genetic variation at 7 microsatellite loci within and among *** investigated small-scale genetic structure with spatial genetic autocorrelation statistics and heterogeneity tests and estimated gene dispersal distances based on population differentiation and on within-population *** was related to habitat characteristics by multiple *** Findings The populations showed high genetic diversity(He=0.64)within populations and rather strong genetic differentiation(F#ST=0.208)among populations,following an isolation-by-distance pattern,which suggests that populations are in gene flow–drift *** SGS was present within populations(mean Sp=0.027).Population density and species diversity had a joint effect on SGS with low population density and high species diversity leading to stronger small-scale *** of historical gene dispersal from between-population differentiation and from within-population SGS resulted in similar values between 4.8 and 22.9 *** results indicate that local-ranged pollen dispersal and inefficient long-distance seed dispersal,both affected by population density and species diversity,contributed to the genetic population structure of the *** suggest that SGS in shrubs is more similar to that of herbs than to trees and that in communities with

关键词： Ardisia crenata BEF China gene flow habitat effects spatial genetic structure

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Wheat yield prediction by zero sink and equilibrium-type soil phosphorus tests

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Pedosphere 2022年第4期32卷 543-554页

作者： walter W.WENZEL Cornelia MESMER Eric J.FLORIDA markus PUSCHENREITER Holger KIRCHMANN Institute of Soil Research Department of Forest and Soil SciencesUniversity of Natural Resources and Life Sciences ViennaKonrad-Lorenz-Straße 24Tulln A-3430Austria College of Agriculture and Forestry Mindanao State University at NaawanNaawan 9023Philippines Department of Soil and Environment Swedish University of Agricultural SciencesBox 701475007 UppsalaLennart Hjelms väg 9Uppsala 75651Sweden

Diffusive gradients in thin films(DGT)measurements have been shown to outperform other phosphorus(P)tests in soils with strong P sorption,but this has not been confirmed for moderately weathered European *** compared the performance of DGT in predicting wheat grain yield in Swedish long-term fertility experiments with those of standard intensity(water-extractable P(P-H2O))and quantity(ammonium lactate-extractable P(P-AL))tests.A Mitscherlich-type model was used to fit wheat yield response to P application rates(0,15,30 or 35,and 45 kg P ha-1 year-1)in each individual trial replicate to estimate the maximum *** trials with clear plateau-type yield responses and the goodness of fit(R2)>0.75,relative yields(RYs)were calculated for each P treatment and plotted against the soil P test results(n=143).The goodness of the Mitscherlich-type fits decreased in the following order:DGT-measured P(P-DGT)(R2=0.35)>P-H2O(R2=0.18)>P-AL(R2=0.13).When excluding soils with P-AL:P-DGT≥0.1 L g-1,R2 was considerably improved to 0.55 for P-AL,0.46 for P-H2O,and 0.65 for P-DGT(n=61).At 95%of maximum yield,the upper limit of P deficiency for P-DGT was 44.8(the soils with P-AL:P-DGT<0.1 L g-1)and 61.9μg L-1(all soils),falling within the range reported for other European and Australian soils(6.0–142μg L-1).We show that in the investigated Swedish soils,DGT performed better than the quantity and intensity tests,which is attributed to its ability to capture P diffusion and resupply from the soil solid phase,similar to plant roots in the rhizosphere.

关键词： ammonium lactate-extractable phosphorus diffusive gradients in thin films(DGT) distribution coefficient long-term field experiment Mitscherlich-type model

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Genetic diversity and differentiation follow secondary succession in a multi-species study on woody plants from subtropical China

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Journal of Plant Ecology 2017年第1期10卷 213-221页

作者： Christoph Z.Hahn Stefan G.Michalski markus Fischer walter Durka Department of Community Ecology(BZF) Helmholtz Centre for Environmental Research—UFZTheodor-Lieser-Straße 4D-06120 HalleGermany Institute of Plant Sciences University of BernAltenbergrain 21CH-3013 BernSwitzerland German Centre for Integrative Biodiversity Research(iDiv)Halle-Jena-Leipzig Deutscher Pl.5E04103 LeipzigGermany

Aims Species diversity and genetic diversity may be affected in parallel by similar environmental ***,genetic diversity may also be affected independently by habitat *** aim at disentangling relationships between genetic diversity,species diversity and habitat characteristics of woody species in subtropical *** We studied 11 dominant tree and shrub species in 27 plots in Gutianshan,China,and assessed their genetic diversity(A_(r))and population differentiation(F′_(ST))with microsatellite *** tested if Ar and population specific F′_(ST) were correlated to local species diversity and plot ***-model inference and model averaging were used to determine the relative importance of each ***,we tested for isolation-by-distance(IBD)and isolation-by-elevation by regressing pairwise F′_(ST) against pairwise spatial and elevational *** Findings Genetic diversity was not related to species diversity for any of the study ***,our results do not support joint effects of habitat characteristics on these two levels of ***,genetic diversity in two understory shrubs,Rhododendron simsii and Vaccinium carlesii,was affected by plot age with decreasing genetic diversity in successionally older *** differentiation increased with plot age in *** and Lithocarpus *** shows that succession can reduce genetic diversity within,and increase genetic diversity between ***,we found four cases of IBD and two cases of *** former indicates inefficient pollen and seed dispersal by animals whereas the latter might be due to phenological *** patterns indicate that succession can affect genetic diversity without parallel effects on species diversity and that gene flow in a continuous subtropical forest can be restricted even at a local scale.

关键词： Allelic richness population differentiation habitat characteristics gene flow species-genetic diversity correlation SGDC

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Intraocular pressure before and after capsulorhexis using two viscoelastic substances and two surgical approaches in enucleated porcine eyes

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International Journal of Ophthalmology(English edition) 2024年第6期17卷 1156-1160页

作者： Chiraz Ben Abdallah walter Sekundo markus SLadewig Daniel M.Handzel Augenzentrum Osthessen Fulda 36037Germany University Eye Hospital Philipps-University Marburg 35043Germany University Eye Hospital Philipps-University Campus FuldaFulda 36043Germany

AIM:To investigate the influence of ophthalmic viscoelastic devices(OVDs)and different surgical approaches on the intraocular pressure(IOP)before and after creation of the curvilinear circular capsulorhexis(CCC)as a measure for anterior chamber stability during this ***:Prospective experimental WetLab study carried out on enucleated porcine *** was measured before and after CCC with the iCare Rebound tonometer(iCare ic200;iCare Finland Oy,Vantaa,Finland).The OVDs used were a cohesive one[Z-Hyalin,Carl Zeiss Meditec AG,Germany;hyaluronic acid(HA)]and a dispersive[Z-Celcoat,Carl Zeiss Meditec AG,Germany;hydroxy propylmethylcellulosis(HPMC)].The CCC was created using Utrata forceps or 23 g microforceps in different combinations with the ***:Using the Utrata forceps the IOP dropped from 63.65±6.44 to 11.25±3.63 mm Hg during the *** use of different OVDs made no *** the 23 g microforceps the IOP dropped from 65.35±8.15 to 36.55±6.09 mm *** difference between IOP drop using either Utrata forceps or 23 g microforceps was highly significant regardless of the OVD ***:Using the sideport for the creation of the capsulorhexis leads to a lesser drop in IOP during this maneuver compared to the main incision in enucleated porcine *** use of different OVD has no significant influence on IOP drop.

关键词： cataract surgery ophthalmosurgical viscoelastic device intraocular pressure capsulorhexis enucleated porcine eye

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Silk-based nerve guidance conduits with macroscopic holes modulate the vascularization of regenerating rat sciatic nerve

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Neural Regeneration Research 2025年第6期20卷 1789-1800页

作者： Carina Hromada Patrick Heimel markus Kerbl LászlóGál Sylvia Nürnberger Barbara Schaedl James Ferguson Nicole Swiadek Xavier Monforte Johannes C.Heinzel Antal Nógrádi Andreas H.Teuschl-Woller David Hercher Department Life Science Engineering University of Applied Sciences Technikum WienViennaAustria Austrian Cluster for Tissue Regeneration ViennaAustria Ludwig Boltzmann Institute for Traumatology The Research Center in Cooperation with AUVAViennaAustria University Clinic of Dentistry Medical University of ViennaViennaAustria Department of Plastic Reconstructive and Aesthetic SurgeryLandesklinikum Wiener Neustadt2700 Wiener NeustadtAustria Department of Anatomy Histology and EmbryologyAlbert Szent-Györgyi Medical SchoolUniversity of SzegedSzegedHungary Medical University of Vienna Department of Orthopedics and Trauma SurgeryDevision of Trauma SurgeryViennaAustria Department of Hand- PlasticReconstructive and Burn SurgeryBG Unfallklinik TuebingenUniversity of TuebingenTuebingenGermany

Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). However, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimizatio

关键词： axon regeneration blood vessel functional recovery macroporous nerve lesion peripheral nerve repair sciatic nerve silk-based nerve guidance conduit vascularization

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Extending harmonized national forest inventory herb layer vegetation cover observations to derive comprehensive biomass estimates

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Forest Ecosystems 2020年第2期7卷 201-214页

作者： markus Didion Forest Resources and Management Swiss Federal Research Institute WSLZürcherstrasse 1118903 BirmensdorfSwitzerland

Background:National forest inventories(NFI)have a long history providing data to obtain nationally representative and accurate estimates of growing ***,in most NFIs additional data are collected to provide information on a range of forest ecosystem functions such as biodiversity,habitat,nutrient and carbon *** important driver of nutrient and C cycling is decomposing biomass produced by forest *** studies have demonstrated that understory vegetation,particularly annual plant litter of the herb layer can contribute significantly to nutrient and C cycling in forests.A methodology to obtain comprehensive,consistent and nationally representative estimates of herb layer biomass on NFI plots could provide added value to NFIs by complementing the existing strong basis of biomass estimates of the tree and tall shrub *** study was based on data from the Swiss NFI since it covers a large environmental gradient,which extends its applicability to other ***:Based on data from 405 measurements in nine forest strata,a parsimonious model formulation was identified to predict total and non-ligneous herb layer *** herb layer cover,elevation was the main statistically significant explanatory variable for *** regression models accurately predicted biomass based on absolute percentage cover(for total biomass:R2=0.65,p=0;for non-ligneous biomass:R2=0.76;p=0)as well as on cover classes(R2=0.83;p=0;and R2=0.79,p=0),which are typically used in *** good performance was supported by the verification with data from repeated *** the 2 nd,3 rd,and 4 th Swiss NFI estimates of non-ligneous above-ground herb layer biomass 586.6±7.7,575.2±7.6,and 586.7±7.9 kg·ha-1,***:The study presents a methodology to obtain herb layer biomass estimates based on a harmonized and standardized attribute available in many *** result of this study was a parsimonious model requiring only elevation data of sample plo

关键词： Model ENFIN Switzerland Ground layer Herbs Ferns Grasses Shrubs Carbon Litter

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Robustness evaluation of cutting tool maintenance planning for soft ground tunneling projects

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Underground Space 2018年第1期3卷 72-85页

作者： Alena Conrads markus Scheffer markus Konig markus Thewes Inastitute of Tunneling cand Construction Management Ruhr-Universitat BochunGermany Chair of Computing in Engineering Ruhr-Universitit BochunGermany

Tunnel boring machines require extensive maintenance and inspection effort to provide a high *** cutting tools of the cutting wheel must be changed timely upon reaching a critical *** one possible maintenance strategy is to change tools only when it is absolutely necessary,tools can also be changed preventively to avoid further *** different maintenance strategies inﬂuence the maintenance duration and the overall project ***,determine downtime related to a particular mainte-nance strategy is still a challenging *** paper shows an analysis of the robustness to achieve the planned project performance of a maintenance strategy considering uncertainties of wear behavior of the cutting tools.A simulation based analysis is presented,imple-menting an empirical wear prediction *** strategies of maintenance planning are compared by performing a parameter vari-ation study including Monte-Carlo *** maintenance costs are calculated and evaluated with respect to their ***,an improved and robust maintenance strategy has been determined.

关键词： Mechanized tunneling,Maintenance Wear of cutting tools Process simulation Robustness Uncertainty modeling

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