EU agricultural reform fails on biodiversity Pe'er, G; Dicks, LV; Visconti, P ...
Science (American Association for the Advancement of Science),
06/2014, Letnik:
344, Številka:
6188
Journal Article
Recenzirano
In December 2013, the European Union (EU) enacted the reformed Common Agricultural Policy (CAP) for 2014-2020, allocating almost 40% of the EU's budget and influencing management of half of its ...terrestrial area. Many EU politicians are announcing the new CAP as "greener," but the new environmental prescriptions are so diluted that they are unlikely to benefit biodiversity. Individual Member States (MSs), however, can still use flexibility granted by the new CAP to design national plans to protect farmland habitats and species and to ensure long-term provision of ecosystem services.
A combined approach: A permanent highly porous bismuth‐containing metal–organic framework (CAU‐7) has been synthesized and its structure determined by a combination of electron diffraction, Rietveld ...refinement, and DFT calculations. The compound is catalytically active in the hydroxymethylation of furan (see picture).
Strong static magnetic fields, as used in magnetic resonance imaging (MRI), stimulate the vestibular inner ear leading to a state of imbalance within the vestibular system that causes nystagmus. This ...magnetic vestibular stimulation (MVS) also modulates fluctuations of resting-state functional MRI (RS-fMRI) networks. MVS can be explained by a Lorentz force model, indicating that MVS is the result of the interaction of the static magnetic field strength and direction (called “B0 magnetic field” in MRI) with the inner ear’s continuous endolymphatic ionic current. However, the high variability between subjects receiving MVS (measured as nystagmus slow-phase velocity and RS-fMRI amplitude modulations) despite matching head position, remains to be explained. Furthermore, within the imaging community, an “easy-to-acquire-and-use” proxy accounting for modulatory MVS effects in RS-fMRI fluctuations is needed. The present study uses MRI data of 60 healthy volunteers to examine the relationship between RS-fMRI fluctuations and the individual orientation of inner-ear anatomy within the static magnetic field of the MRI. The individual inner-ear anatomy and orientation were assessed via high-resolution anatomical CISS images and related to fluctuations of RS-fMRI networks previously associated with MVS. More specifically, we used a subject-specific proxy for MVS (pMVS) that corresponds to the orientation of the individual inner-ear anatomy within the static magnetic field direction (also called “
z
-direction” in MR imaging). We found that pMVS explained a considerable fraction of the total variance in RS-fMRI fluctuations (for instance, from 11% in the right cerebellum up to 36% in the cerebellar vermis). In addition to pMVS, we examined the angle of Reid’s plane, as determined from anatomical imaging as an alternative and found that this angle (with the same sinus transformation as for pMVS) explained considerably less variance, e.g., from 2 to 16%. In our opinion, an excess variability due to MVS should generally be addressed in fMRI research analogous to nuisance regression for movement, pulsation, and respiration effects. We suggest using the pMVS parameter to deal with modulations of RS-fMRI fluctuations due to MVS. MVS-induced variance can easily be accounted by using high-resolution anatomical imaging of the inner ear and including the proposed pMVS parameter in fMRI group-level analysis.
The aim of this 15O-labelled H2O bolus positron emission tomography (PET) study was to analyse the hemispheric dominance of the vestibular cortical system. Therefore, the differential effects of ...caloric vestibular stimulation (right or left ear irrigation with warm water at 44°C) on cortical and subcortical activation were studied in 12 right-handed and 12 left-handed healthy volunteers. Caloric irrigation induces a direction-specific sensation of rotation and nystagmus. Significant regional cerebral blood flow increases were found in a network within both hemispheres, including the superior frontal gyrus/sulcus, the precentral gyrus and the inferior parietal lobule with the supramarginal gyrus. These areas correspond best to the cortical ocular motor centres, namely the prefrontal cortex, the frontal eye field and the parietal eye field, known to be involved in the processing of caloric nystagmus. Furthermore, distinct temporo-parietal activations could be separated in the posterior part of the insula with the adjacent superior temporal gyrus, the inferior parietal lobule and precuneus. These areas fit best to the human homologues of multisensory vestibular cortex areas identified in the monkey and correspond to the parieto-insular vestibular cortex (PIVC), the visual temporal sylvian area (VTS) and areas 7 and 6. Further cortical activations were seen in the anterior insula, the inferior frontal gyrus and anterior cingulum. The subcortical activation pattern in the putamen, thalamus and midbrain is consistent with the organization of efferent ocular motor pathways. Cortical and subcortical activation of the described areas was bilateral during monaural stimulation, but predominant in the hemisphere ipsilateral to the stimulated ear and exhibited a significant right hemispheric dominance for vestibular and ocular motor structures in right-handed volunteers. Similarly, a significant left hemispheric dominance was found in the 12 left-handed volunteers. Thus, this PET study showed for the first time that cortical and subcortical activation by vestibular caloric stimulation depends (i) on the handedness of the subjects and (ii) on the side of the stimulated ear. Maximum activation was therefore found when the non-dominant hemisphere was ipsilateral to the stimulated ear, i.e. in the right hemisphere of right-handed subjects during caloric irrigation of the right ear and in the left hemisphere of left-handed subjects during caloric irrigation of the left ear. The localization of handedness and vestibular dominance in opposite hemispheres might conceivably indicate that the vestibular system and its hemispheric dominance, which matures earlier during ontogenesis, determine right- or left-handedness.
The successful cortical processing of multisensory input typically requires the integration of data represented in different reference systems to perform many fundamental tasks, such as bipedal ...locomotion. Animal studies have provided insights into the integration processes performed by the neocortex and have identified region specific tuning curves for different reference frames during ego-motion. Yet, there remains almost no data on this topic in humans.
In this study, an experiment originally performed in animal research with the aim to identify brain regions modulated by the position of the head and eyes relative to a translational ego-motion was adapted for humans. Subjects sitting on a motion platform were accelerated along a translational pathway with either eyes and head aligned or a 20° yaw-plane offset relative to the motion direction while EEG was recorded.
Using a distributed source localization approach, it was found that activity in area PFm, a part of Brodmann area 40, was modulated by the congruency of translational motion direction, eye, and head position. In addition, an asymmetry between the hemispheres in the opercular-insular region was observed during the cortical processing of the vestibular input. A frequency specific analysis revealed that low-frequency oscillations in the delta- and theta-band are modulated by vestibular stimulation. Source-localization estimated that the observed low-frequency oscillations are generated by vestibular core-regions, such as the parieto-opercular region and frontal areas like the mid-orbital gyrus and the medial frontal gyrus.
Functional (psychogenic) dizziness Dieterich, M; Staab, J P; Brandt, T
Handbook of clinical neurology,
2016, Letnik:
139
Journal Article
Recenzirano
Functional and psychiatric disorders that cause vestibular symptoms (i.e., vertigo, unsteadiness, and dizziness) are common. In fact, they are more common than many well-known structural vestibular ...disorders. Neurologists and otologists are more likely to encounter patients with vestibular symptoms due to persistent postural-perceptual dizziness or panic disorder than Ménière's disease or bilateral vestibular loss. Successful approaches to identifying functional and psychiatric causes of vestibular symptoms can be incorporated into existing practices without much difficulty. The greatest challenge is to set aside dichotomous thinking that strongly emphasizes investigations of structural diseases in favor of a three-pronged approach that assesses structural, functional, and psychiatric disorders simultaneously. The pathophysiologic mechanisms underlying functional and psychiatric causes of vestibular symptoms are better understood than many clinicians realize. Research methods such as advanced posturographic analysis and functional brain imaging will push this knowledge further in the next few years. Treatment plans that include patient education, vestibular rehabilitation, cognitive and behavioral therapies, and medications substantially reduce morbidity and offer the potential for sustained remission when applied systematically. Diagnostic and therapeutic approaches are necessarily multidisciplinary in nature, but they are well within the purview of collaborative care teams or networks of clinicians coordinated with the neurologists and otologists whom patients consult first.
Sound-induced vestibular-evoked myogenic potentials (VEMPs) can be used to investigate saccular function, measured from the tonically contracted sternocleidomastoid muscles (SCM) in response to loud ...sound stimuli. The aim of the present study was to assess VEMPs in patients with vestibular migraine and to determine whether saccular function is affected by the disease. Furthermore, tests such as tilts of subjective visual vertical (SVV) and caloric testing were conducted to test whether deficits in the various tests are associated with each other. The amplitude and latency of VEMPs were measured from the SCM in 63 patients with vestibular migraine (median age 47 years; range 24–70 years) and compared with those of 63 sex- and age-matched healthy controls (median age 46 years; range 17–73 years). Of the 63 patients with vestibular migraine, 43 (68%) had reduced EMG-corrected VEMP amplitudes compared to the controls. Thus, the mean of the p13–n23 amplitudes of the vestibular migraine patients were 1.22 (SE ±0.09) for the right and 1.21 (SE ±0.09) for the left side, whereas the averaged amplitudes of the 63 healthy controls showed a mean of 1.79 (SE ±0.09) on the right and of 1.76 (SE ±0.09) on the left. No difference was seen in the latencies and there was no correlation between VEMP amplitudes, tilts of SVV and caloric testing. Our data on patients with vestibular migraine indicate that the VEMP amplitudes are significantly and bilaterally reduced compared to those of controls. This electrophysiological finding suggests that both peripheral vestibular structures, such as the saccule, but also central vestibular structures are affected. Thus, beside the brainstem, structures in the inner ear also seem to contribute to vertigo in vestibular migraine.
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