Tracing of Neuronal Connections in the Human Brain by Magnetic Resonance Imaging in vivo

Axon degeneration after disruption of fibre tracts in the mammalian nervous system is accompanied by myelin breakdown which leads to changes in its magnetic resonance properties. In two patients with pure motor strokes due to small ischaemic lesions restricted to the internal capsule, magnetic resonance imaging disclosed a narrow band of pathological signal increase descending band-like into the brain stem and ascending to the precentral gyrus, which corresponded to the well-known path of the pyramidal tract. The findings suggest that in man anterograde and possibly retrograde fibre degeneration can be traced in vivo by conventional magnetic resonance imaging techniques. Critical conditions are the presence of small, strategically located lesions, appropriate choice of imaging plane, and the interval between time of lesion and of imaging. This demonstration may open a new era for functional neuroanatomy of man

Motor recovery following capsular stroke

The functional anatomy of motor recovery was studied by assessing motor function quantitatively in 23 patients following capsular or striatocapsular stroke. While selective basal ganglia lesions (caudate and/or putamen exclusively) did not affect voluntary movements of the extremities, lesions of the anterior (plus caudate/putamen) or posterior limb of the internal capsule led to an initially severe motor impairment followed by excellent recovery, hand function included. In contrast, lesions of the posterior limb of the internal capsule in combination with damage to lateral thalamus compromised motor outcome. In experimental tracing of the topography of the internal capsule in macaque monkeys, we found axons of primary motor cortex passing through the middle third of the posterior limb of the internal capsule. Axons of premotor cortex (dorsolateral and post-arcuate area 6) passed through the capsular genu, and those of supplementary motor area (mesial area 6) through the anterior limb. Small capsular lesion can therefore disrupt the output of functionally and anatomically distinct motor areas selectively. The clinically similar motor deficits with a similar course of functional restitution following disruption of these different descending motor pathways indicate a parallel operation of cortical motor areas. They may have the further capability of substituting each other functionally in the process of recovery from hemiparesis

Effect of sainfoin (Onobrychis viciifolia) silage and hay against gastrointestinal nematodes in lambs

The objective of the study was to examine the effect of dried and ensiled sainfoin (Onobrychis viciifolia) against two species of gastrointestinal nematodes (Haemonchus contortus, Cooperia curticei) in lambs. Twenty-four days post experimental infection, 24 lambs were allocated to 4 equal groups. Group A and B received sainfoin silage and control silage respectively for 16 days. Groups C and D were fed on sainfoin hay or control hay for the same period. Feeds were administered ad libitum and mean refusals and live weight were regularly recorded. Individual faecal egg counts (FEC) were performed twice weekly. After the feeding period all lambs were slaughtered for post mortem investigation. The consumption of sainfoin hay was associated with a significant reduction of the adult H. contortus burden by 47 % (P < 0.05) whereas no significant difference was seen when feeding sainfoin silage (49 %, P = 0.112). The C. curticei worm burden was not significantly reduced by either sainfoin hay or silage. At slaughter FEC were significantly reduced by sainfoin hay by 64 % (P < 0.001) compared to the control feed. After feeding sainfoin silage FEC decreased by 48 % (P = 0.056). There was a tendency of better live weight gain in sainfoin hay fed animals compared to the control fed ones (P=0.07). These results demonstrate a nematocidal effect of a tanniferous forage legume against gastrointestinal nema¬¬todes, which was more pronounced against H. contortus. The antiparasitic effects were largely preserved when feeding sainfoin silage, suggesting this conservation procedure to be a valuable alternative to hay

Integration of Pulsed Electric Fields in the Biorefinery Concept to Extract Microalgae Components of Interest for Food Industry

The high cultivation costs for microalgae and the complex and costly downstream processing make the price per ton of raw materials from microalgae biomass, such as biofuel, uneconomic. To overcome this detriment, it is suggested to use the residual biomass for biofuel production after obtaining high- and middle-value products. Microalgae are an attractive food source, since they are rich in proteins, peptides, carbohydrates, lipids, and other essential nutrients with protective and detoxifying roles (vitamins, minerals, pigments). A major problem is that these valuable components cannot be accessed without prior and adequate cell disruption. This chapter discusses a new strategy to integrate PEF treatment into biorefinery concept by implementation of an incubation step which facilitates the release of intracellular components after PEF treatment. Based on the results obtained from the microalgae Chlorella vulgaris and the cyanobacteria Arthrospira platensis, the dependence of various influencing factors such as temperature, pH value, and biomass concentration on protein release during the incubation step is shown. Finally, the efficiency of this approach is discussed

On the Stretch Factor of Polygonal Chains

Let P=(p_1, p_2, ..., p_n) be a polygonal chain. The stretch factor of P is the ratio between the total length of P and the distance of its endpoints, sum_{i = 1}^{n-1} |p_i p_{i+1}|/|p_1 p_n|. For a parameter c >= 1, we call P a c-chain if |p_ip_j|+|p_jp_k| <= c|p_ip_k|, for every triple (i,j,k), 1 <= i<j<k <= n. The stretch factor is a global property: it measures how close P is to a straight line, and it involves all the vertices of P; being a c-chain, on the other hand, is a fingerprint-property: it only depends on subsets of O(1) vertices of the chain. We investigate how the c-chain property influences the stretch factor in the plane: (i) we show that for every epsilon > 0, there is a noncrossing c-chain that has stretch factor Omega(n^{1/2-epsilon}), for sufficiently large constant c=c(epsilon); (ii) on the other hand, the stretch factor of a c-chain P is O(n^{1/2}), for every constant c >= 1, regardless of whether P is crossing or noncrossing; and (iii) we give a randomized algorithm that can determine, for a polygonal chain P in R^2 with n vertices, the minimum c >= 1 for which P is a c-chain in O(n^{2.5} polylog n) expected time and O(n log n) space

Relaxation of Subgraph Queries Delivering Empty Results

Graph databases with the property graph model are used in multiple domains including social networks, biology, and data integration. They provide schema-flexible storage for data of a different degree of a structure and support complex, expressive queries such as subgraph isomorphism queries. The exibility and expressiveness of graph databases make it difficult for the users to express queries correctly and can lead to unexpected query results, e.g. empty results. Therefore, we propose a relaxation approach for subgraph isomorphism queries that is able to automatically rewrite a graph query, such that the rewritten query is similar to the original query and returns a non-empty result set. In detail, we present relaxation operations applicable to a query, cardinality estimation heuristics, and strategies for prioritizing graph query elements to be relaxed. To determine the similarity between the original query and its relaxed variants, we propose a novel cardinality-based graph edit distance. The feasibility of our approach is shown by using real-world queries from the DBpedia query log

Functional neuroanatomy of the rhinophore of Aplysia punctata

BACKGROUND: For marine snails, olfaction represents a crucial sensory modality for long-distance reception, as auditory and visual information is limited. The posterior tentacle of Aplysia, the rhinophore, is a chemosensory organ and several behavioural studies showed that the rhinophores can detect pheromones, initiate orientation and locomotion toward food. However the functional neuroanatomy of the rhinophore is not yet clear. Here we apply serotonin-immunohistochemistry and fluorescent markers in combination with confocal microscopy as well as optical recording techniques to elucidate the structure and function of the rhinophore of the sea slug Aplysia punctata. RESULTS: With anatomical techniques an overview of the neuroanatomical organization of the rhinophore is presented. Labelling with propidium iodide revealed one layer of cell nuclei in the sensory epithelium and densely packed cell nuclei beneath the groove of the rhinophore, which extends to about two third of the total length of the rhinophore. Serotonin immunoreactivity was found within the olfactory glomeruli underneath the epithelium as well as in the rhinophore ganglion. Retrograde tracing from the rhinophore ganglion with 4-(4-(dihexadecylamino)styryl)-N-methylpyridinium iodide (DiA) demonstrated the connection of glomeruli with the ganglion. Around 36 glomeruli (mean diameter 49 μm) were counted in a single rhinophore. Fluorimetric measurements of intracellular Ca(2+ )levels using Fura-2 AM loading revealed Ca(2+)-responses within the rhinophore ganglion to stimulation with amino acids. Bath application of different amino acids revealed differential responses at different positions within the rhinophore ganglion. CONCLUSION: Our neuroanatomical study revealed the number and position of glomeruli in the rhinophore and the rhinophore ganglion as processing stage of sensory information. Serotonin-immunoreactive processes were found extensively within the rhinophore, but was not detected within any peripheral cell body. Amino acids were used as olfactory stimuli in optical recordings and induced sensory responses in the rhinophore ganglion. The complexity of changes in intracellular Ca(2+)-levels indicates, that processing of odour information takes place within the rhinophore ganglion. Our neuroanatomical and functional studies of the rhinophore open up a new avenue to analyze the olfactory system in Aplysia