Microclimate effects of short rotation tree-strips in Germany

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Historicization without periodization: post-postmodernism and the poetics of politics

A large number of recent scholarship in (American) literary and cultural studies is devoted to describing the contemporary moment as a monumental break from the previous (or current) period, postmodernism, by hailing our contemporary times as the era of post-postmodernism, late postmodernism, metamodernism, cosmodernism, or of a similarly termed construction. In these different proclamations, we recognize a pervasive tendency to periodize, an attempt to separate phases of human existence and cultural creation into neat stages that ‘logically’ follow after one another to form a supposedly coherent narrative. This practice of periodizing comes with a number of pitfalls that many of these studies seem not fully aware of, and it in turn speaks to (and characterizes) the contemporary moment as one marked by a desire for the boundedness of such clear divisions. In the following pages, we chronicle the quandaries that follow from such implicit and explicit efforts of periodization by focalizing them through three different ‘creation myths’ of the contemporary that such efforts at periodization typically subscribe to. As a way of sidestepping these, we accentuate the strengths of more ‘local’ critical lenses, approaches that historicize without periodizing. As one such lens, we suggest to engage the contemporary moment through the ‘poetics of politics,’ a historical discursive formation in which literary and popular texts’ desire for political relevance is matched by a recognition, in politics, of the (meta)textual quality of political action

Participating Audiences, Imagined Public Spheres: The Cultural Work of Contemporary American(ized) Narratives - Introduction

This is a book about contemporary American(ized) narratives and the audiences they call into being. It brings together eight very diverse case studies covering and investigating a wide range of media, genres, and modes to ask how contemporary 'texts' encourage 'imagined communities' of readers/viewers that operate as 'public spheres' of social and political deliberation, self-fashioning, and debate. In asking this question, the contributions collected in this volume shift perspectives in a number of ways: They question the boundary between the audiences of (often popular and broadly circulating) narratives on the one side and national public spheres on the other; they thus encourage rereading the transnational mobility of American(ized) narratives not simply as a phenomenon of popular culture but as an indicator of emerging transnational public spheres; and they invite us to look closely at the narrative dynamics with which these texts operate their audiences as public spheres

An objective functional evaluation of myoelectrically-controlled hand prostheses: A pilot study using the virtual peg insertion test

Assessing upper limb prostheses and their influence when performing goal-directed activities is essential to compare the quality of different devices and optimize their control settings. Currently available assessments are often subjective, insensitive, and cannot provide a detailed evaluation of prostheses and their usage. The goal of this pilot study was to explore the feasibility of using the Virtual Peg Insertion Test (VPIT) to provide an in-depth assessment of a prosthesis and its functional performance. One transradial amputee performed the goal-directed manipulation task of the VPIT with the sound body side and four different myoelectrically-controlled prostheses. The subject was able to complete the VPIT protocol successfully with technically advanced prosthesis (two out of four devices). The kinematic- and kinetic-based objective evaluation measures extracted from the VPIT were able to capture clear differences between the sound and amputated body side and were able to identify varying movement patterns for different prostheses. Additionally, the outcome measures were sensitive to changes in prosthesis control settings and showed clear trends across measures of subjectively perceived prosthesis quality assessed through a questionnaire. This work demonstrates the general feasibility of objectively evaluating functional prosthesis usage with the VPIT

Impact of black locust hedgerows on wind velocity and wind erosion in eastern Germany

PresentationThe production of energy wood on arable land increased in Germany during the last years. Black locust (Robinia pseudoacacia L.) is a suitable tree species in order to ensure substantial woody biomass yields on agricultural sites in eastern Germany. Arranged in hedge structures (alley cropping) positive effects on wind velocity and hence on soil erosion can be expected for the whole agricultural production area. Results of field measurements carried out in several alley cropping sites located in eastern Germany show that wind velocity can be reduced by more than 50 percent, even though tree hedgerows were not higher than four meters. Here, the reduction of wind speed was depending on the distance to woody crops, the width of the crop alleys and the orientation of hedgerows. As a result of wind speeds reduction the potential of soil erosion by wind decreases considerably. The risk of wind erosion is even nearly negligible for 24 m wide or smaller crop alleys. In this presentation, wind velocity data of comprehensive measurements will be shown depending on tree height and arrangement of black locust hedgerows. Moreover, derived from wind speed results specific statements about soil erosion risk by wind are given, taking into account soil texture data

Alley cropping - a promising multifunctional form of land use for reclaimed lignite mine sites in Germany

PresentationSince the 1920s more than 80.000 ha land were affected by lignite open cast mining activities in the Lusatia region (Eastern Germany). Subsequently, large post-mining landscapes with substrates poor in humus and nutrients evolved in this region. As a result the conventional crop production on those post-mine areas is comparably restricted. Against this background, the increasing demand for woody biomass for bioenergy and thus the cultivation of fast growing trees for woody biomass production could represent a promising option to enhance the productivity of reclaimed mine land. Thus, considerable research were carried out on reclaiming technologies and improving soil quality with different fast growing tree species in the Lusatia lignite region over the past two decades. It has been shown that a sustainable supply of bioenergy wood is possible with black locust (Robinia pseudoacacia L.) trees even under the unfavorable growth conditions in the marginal post mining area. Since this knowledge is mainly based on studies of monocultural plantations (SRC) in 2007 a short rotation alley cropping system (SRACS) was established in the reclaimed lignite mine site “Welzow-Süd” (25 km south of Cottbus). The present study examines the results of seven years of field measurements carried out within this SRACS in terms of three major environmental and economic benefits of agroforestry: 1) biomass production, 2) soil nutrition and 3) wind velocity reduction, which all can significantly contribute to a successful rehabilitation of degraded landscapes

KIC 4247791: A SB4 system with two eclipsing binaries (2EBs)

KIC 4247791 is an eclipsing binary observed by the Kepler satellite mission. We wish to determine the nature of its components and in particular the origin of a shallow dip in its Kepler light curve that previous investigations have been unable to explain in a unique way. We analyze newly obtained high-resolution spectra of the star using synthetic spectra based on atmosphere models, derive the radial velocities of the stellar components from cross-correlation with a synthetic template, and calculate the orbital solution. We use the JKTEBOP program to model the Kepler light curve of KIC 4247791. We find KIC 4247791 to be a SB4 star. The radial velocity variations of its four components can be explained by two separate eclipsing binaries. In contradiction to previous photometric findings, we show that the observed composite spectrum as well as the derived masses of all four of its components correspond to spectral type F. The observed small dip in the light curve is not caused by a transit-like phenomenon but by the eclipses of the second binary system. We find evidence that KIC 4247791 might belong to the very rare hierarchical SB4 systems with two eclipsing binaries.Comment: 6 pages, 8 figures, 2 table

Characterizing reproducibility of cerebral hemodynamic responses when applying short-channel regression in functional near-infrared spectroscopy

Significance: Functional near-infrared spectroscopy (fNIRS) enables the measurement of brain activity noninvasively. Optical neuroimaging with fNIRS has been shown to be reproducible on the group level and hence is an excellent research tool, but the reproducibility on the single-subject level is still insufficient, challenging the use for clinical applications. Aim: We investigated the effect of short-channel regression (SCR) as an approach to obtain fNIRS measurements with higher reproducibility on a single-subject level. SCR simultaneously considers contributions from long- and short-separation channels and removes confounding physiological changes through the regression of the short-separation channel information. Approach: We performed a test-retest study with a hand grasping task in 15 healthy subjects using a wearable fNIRS device, optoHIVE. Relevant brain regions were localized with transcranial magnetic stimulation to ensure correct placement of the optodes. Reproducibility was assessed by intraclass correlation, correlation analysis, mixed effects modeling, and classification accuracy of the hand grasping task. Further, we characterized the influence of SCR on reproducibility. Results: We found a high reproducibility of fNIRS measurements on a single-subject level ( and correlation ). SCR increased the reproducibility from 0.64 to 0.81 ( ) but did not affect classification (85% overall accuracy). Significant intersubject variability in the reproducibility was observed and was explained by Mayer wave oscillations and low raw signal strength. The raw signal-to-noise ratio (threshold at 40 dB) allowed for distinguishing between persons with weak and strong activations. Conclusions: We report, for the first time, that fNIRS measurements are reproducible on a single-subject level using our optoHIVE fNIRS system and that SCR improves reproducibility. In addition, we give a benchmark to easily assess the ability of a subject to elicit sufficiently strong hemodynamic responses. With these insights, we pave the way for the reliable use of fNIRS neuroimaging in single subjects for neuroscientific research and clinical applications

Characterizing reproducibility of cerebral hemodynamic responses when applying short-channel regression in functional near-infrared spectroscopy.

Significance: Functional near-infrared spectroscopy (fNIRS) enables the measurement of brain activity noninvasively. Optical neuroimaging with fNIRS has been shown to be reproducible on the group level and hence is an excellent research tool, but the reproducibility on the single-subject level is still insufficient, challenging the use for clinical applications. Aim: We investigated the effect of short-channel regression (SCR) as an approach to obtain fNIRS measurements with higher reproducibility on a single-subject level. SCR simultaneously considers contributions from long- and short-separation channels and removes confounding physiological changes through the regression of the short-separation channel information. Approach: We performed a test-retest study with a hand grasping task in 15 healthy subjects using a wearable fNIRS device, optoHIVE. Relevant brain regions were localized with transcranial magnetic stimulation to ensure correct placement of the optodes. Reproducibility was assessed by intraclass correlation, correlation analysis, mixed effects modeling, and classification accuracy of the hand grasping task. Further, we characterized the influence of SCR on reproducibility. Results: We found a high reproducibility of fNIRS measurements on a single-subject level ( and correlation ). SCR increased the reproducibility from 0.64 to 0.81 ( ) but did not affect classification (85% overall accuracy). Significant intersubject variability in the reproducibility was observed and was explained by Mayer wave oscillations and low raw signal strength. The raw signal-to-noise ratio (threshold at 40 dB) allowed for distinguishing between persons with weak and strong activations. Conclusions: We report, for the first time, that fNIRS measurements are reproducible on a single-subject level using our optoHIVE fNIRS system and that SCR improves reproducibility. In addition, we give a benchmark to easily assess the ability of a subject to elicit sufficiently strong hemodynamic responses. With these insights, we pave the way for the reliable use of fNIRS neuroimaging in single subjects for neuroscientific research and clinical applications

A low-dimensional representation of arm movements and hand grip forces in post-stroke individuals

Characterizing post-stroke impairments in the sensorimotor control of arm and hand is essential to better understand altered mechanisms of movement generation. Herein, we used a decomposition algorithm to characterize impairments in end-effector velocity and hand grip force data collected from an instrumented functional task in 83 healthy control and 27 chronic post-stroke individuals with mild-to-moderate impairments. According to kinematic and kinetic raw data, post-stroke individuals showed reduced functional performance during all task phases. After applying the decomposition algorithm, we observed that the behavioural data from healthy controls relies on a low-dimensional representation and demonstrated that this representation is mostly preserved post-stroke. Further, it emerged that reduced functional performance post-stroke correlates to an abnormal variance distribution of the behavioural representation, except when reducing hand grip forces. This suggests that the behavioural repertoire in these post-stroke individuals is mostly preserved, thereby pointing towards therapeutic strategies that optimize movement quality and the reduction of grip forces to improve performance of daily life activities post-stroke