3,738 research outputs found
Die 'Westforschung' zum europäischen Nordwesten als Gegenstand der Zeit- und Wissenschaftsgeschichte
The German \"Westforschung\" (Western Research) of the 1920s to 1960s, i.e. the interdisciplinary cross-border study of the region west of the Rhine into Germany\'s neighbouring countries, has recently become topical within the wider discussion on the contribution of German scholars to National Socialism. Developed after World War I in a defensive stance against French claims on the Rhineland, it later served, intentionally or not, as a (pseudo-)legitimisation for the national-socialist aggression to the west in 1940. The article presents an overview of the northern variant of Westforschung regarding the Low Countries, a special case, not the least because important contributions came from Dutch and Belgian scholars and because this paradigm did not end in 1945 but continued to prevail until the early 1960s
Impaired facilitation of motor evoked potentials in incomplete spinal cord injury
Objectives: To improve the diagnosis of damaged spinal motor pathways in incomplete spinal cord injury (iSCI) by assessing the facilitation of lower limbs motor evoked potentials (MEP). Methods: Control subjects (n = 12) and iSCI patients (n = 21) performed static and dynamic isometric foot dorsiflexions. MEPs induced by transcranial magnetic stimulation and EMG background of tibialis anterior muscle (TA) were analyzed. Static and dynamic muscle activation was performed at comparable levels of maximal voluntary contraction (MVC). The influence of the motor tasks on the excitability and facilitation of MEPs was compared between controls and iSCI patients. Results: In the controls an increased facilitation of TA MEP at lower levels of dynamic compared with static activation (10-20% MVC) could be shown. At matched EMG background level the MEP responses were significantly increased. In the iSCI patients at a comparable level of TA activation the MEP responses were significantly reduced and 3 different patterns of MEP responses could be distinguished: i) preserved increment of TA MEP in the dynamic motor task, ii) unchanged MEP size in the dynamic and static motor task, and iii) elicitable MEPs in the dynamic motor task,which were abolished in the static motor task. Conclusions: Static and dynamic motor tasks have different effects on TA MEP facilitation. The task-dependent modulation of TA MEPs is comparable to that described for upper limb muscles. Complementary to the MEP delay this approach allows for an estimation of the severity of spinal tract damage. The task-dependent modulation of TA MEPs is an additional diagnostic tool to improve the assessment and monitoring of motor function in iSC
In search of virus carriers of the 1988 and 2002 phocine distemper virus outbreaks in European harbour seals
European harbour seal (Phoca vitulina) populations decreased substantially during the phocine distemper virus (PDV) outbreaks of 1988 and 2002. Different hypotheses have stated that various seals and terrestrial carnivore species might be the source of infection. To further analyse these hypotheses, grey (Halichoerus grypus) and ringed (Phoca hispida) seals, polar bears (Ursus maritimus) and minks (Mustela lutreola) were sampled from the North Sea and East Greenland coasts between 1988 and 2004 and investigated by RT-PCR using a panmorbillivirus primer pair. However, all samples were negative for morbillivirus nucleic acid
Microwave realization of quasi one-dimensional systems with correlated disorder
A microwave setup for mode-resolved transport measurement in
quasi-one-dimensional (quasi-1D) structures is presented. We will demonstrate a
technique for direct measurement of the Green's function of the system. With
its help we will investigate quasi-1D structures with various types of
disorder. We will focus on stratified structures, i.e., structures that are
homogeneous perpendicular to the direction of wave propagation. In this case
the interaction between different channels is absent, so wave propagation
occurs individually in each open channel. We will apply analytical results
developed in the theory of one-dimensional (1D) disordered models in order to
explain main features of the quasi-1D transport. The main focus will be
selective transport due to long-range correlations in the disorder. In our
setup, we can intentionally introduce correlations by changing the positions of
periodically spaced brass bars of finite thickness. Because of the equivalence
of the stationary Schr\"odinger equation and the Helmholtz equation, the result
can be directly applied to selective electron transport in nanowires,
nanostripes, and superlattices.Comment: 11 pages, 9 figure
Experimental Test of a Two-dimensional Approximation for Dielectric Microcavities
Open dielectric resonators of different shapes are widely used for the
manufacture of microlasers. A precise determination of their resonance
frequencies and widths is crucial for their design. Most microlasers have a
flat cylindrical geometry, and a two-dimensional approximation, the so-called
method of the effective index of refraction, is commonly employed for numerical
calculations. Our aim has been an experimental test of the precision and
applicability of a model based on this approximation. We performed very
thorough and accurate measurements of the resonance frequencies and widths of
two passive circular dielectric microwave resonators and found significant
deviations from the model predictions. From this we conclude that the model
generally fails in the quantitative description of three-dimensional dielectric
resonators.Comment: 10 pages, 13 figure
Annotated bibliography for the Scoping study “Improving the perspective for regional trade and investment in West-Africa: the key to food security, economic development and stability in the region?”
ASC – Publicaties niet-programma gebonde
PT symmetry and spontaneous symmetry breaking in a microwave billiard
We demonstrate the presence of parity-time (PT) symmetry for the
non-Hermitian two-state Hamiltonian of a dissipative microwave billiard in the
vicinity of an exceptional point (EP). The shape of the billiard depends on two
parameters. The Hamiltonian is determined from the measured resonance spectrum
on a fine grid in the parameter plane. After applying a purely imaginary
diagonal shift to the Hamiltonian, its eigenvalues are either real or complex
conjugate on a curve, which passes through the EP. An appropriate basis choice
reveals its PT symmetry. Spontaneous symmetry breaking occurs at the EP
Allomonal effect of breath contributes to differential attractiveness of humans to the African malaria vector Anopheles gambiae
BACKGROUND: Removal of exhaled air from total body emanations or artificially standardising carbon dioxide (CO(2)) outputs has previously been shown to eliminate differential attractiveness of humans to certain blackfly (Simuliidae) and mosquito (Culicidae) species. Whether or not breath contributes to between-person differences in relative attractiveness to the highly anthropophilic malaria vector Anopheles gambiae sensu stricto remains unknown and was the focus of the present study. METHODS: The contribution to and possible interaction of breath (BR) and body odours (BO) in the attraction of An. gambiae s.s. to humans was investigated by conducting dual choice tests using a recently developed olfactometer. Either one or two human subjects were used as bait. The single person experiments compared the attractiveness of a person's BR versus that person's BO or a control (empty tent with no odour). His BO and total emanations (TE = BR+BO) were also compared with a control. The two-person experiments compared the relative attractiveness of their TE, BO or BR, and the TE of each person against the BO of the other. RESULTS: Experiments with one human subject (P(1)) as bait found that his BO and TE collected more mosquitoes than the control (P = 0.005 and P < 0.001, respectively), as did his BO and the control versus his BR (P < 0.001 and P = 0.034, respectively). The TE of P(1 )attracted more mosquitoes than that of another person designated P(8 )(P < 0.021), whereas the BR of P(8 )attracted more mosquitoes than the BR of P(1 )(P = 0.001). The attractiveness of the BO of P(1 )versus the BO of P(8 )did not differ (P = 0.346). The BO from either individual was consistently more attractive than the TE from the other (P < 0.001). CONCLUSIONS: We demonstrated for the first time that human breath, although known to contain semiochemicals that elicit behavioural and/or electrophysiological responses (CO(2), ammonia, fatty acids) in An. gambiae also contains one or more constituents with allomonal (~repellent) properties, which inhibit attraction and may serve as an important contributor to between-person differences in the relative attractiveness of humans to this important malaria vector
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