Table of Contents and Prologue

Editorial board, Table of contents, and Prologue, an introduction to volume 1

A NEW ANALYSIS OF Nd-Fe-B BASED PERMANENT MAGNETS

A large number of sintered Nd-Fe-B based magnets with three different heat treatments and also substituted samples (Nd by Dy, Fe by Co or both) were investigated by measuring the temperature dependence of both coercivity and anisotropy field. Additionally the ratio between Nd and (Fe, B) was varied systematically. These data were analysed using a nucleation model description. The reliability of this model was proved by comparing the analysis with that performed on a Sm2Co17 based magnet

Hedgerows Have a Barrier Effect and Channel Pollinator Movement in the Agricultural Landscape

Agricultural intensification and the subsequent fragmentation of semi-natural habitats severely restrict pollinator and pollen movement threatening both pollinator and plant species. Linear landscape elements such as hedgerows are planted for agricultural and conservation purposes to increase the resource availability and habitat connectivity supporting populations of beneficial organisms such as pollinators. However, hedgerows may have unexpected effects on plant and pollinator persistence by not just channeling pollinators and pollen along, but also restricting movement across the strip of habitat. Here, we tested how hedgerows influence pollinator movement and pollen flow. We used fluorescent dye particles as pollen analogues to track pollinator movement between potted cornflowers Centaurea cyanus along and across a hedgerow separating two meadows. The deposition of fluorescent dye was significantly higher along the hedgerow than across the hedgerow and into the meadow, despite comparable pollinator abundances. The differences in pollen transfer suggest that hedgerows can affect pollinator and pollen dispersal by channeling their movement and acting as a permeable barrier. We conclude that hedgerows in agricultural landscapes can increase the connectivity between otherwise isolated plant and pollinator populations (corridor function), but can have additional, and so far unknown barrier effects on pollination services. Functioning as a barrier, linear landscape elements can impede pollinator movement and dispersal, even for highly mobile species such as bees. These results should be considered in future management plans aiming to enhance the persistence of threatened pollinator and plant populations by restoring functional connectivity and to ensure sufficient crop pollination in the agricultural landscape

Importance of core and linear marsh elements for wetland arthropod diversity in an agricultural landscape

The importance of linear habitat elements connecting core habitat patches for biodiversity conservation is still poorly understood. We surveyed reed strips along drainage ditches and reed marshes in an agricultural landscape to assess how both the density of linear habitat elements and the area of core habitat affect diversity and community composition of spiders, ground beetles, and long-legged flies. For each taxonomic group, species composition of both all' and typical wetland' species, but not species richness was different between ditches and marshes. Overall local species richness and richness of species of conservation interest were affected at a landscape scale both by the density of ditches and by the area of core wetland. Strength and direction of these effects differed among groups. An increase in the density of reed ditches positively affected the total species richness of spiders and ground beetles and the species richness of typical wetland ground beetles, but not for long-legged flies and typical wetland spiders. The positive effects were explained by improved network functionality, rather than by increase in available habitat area at landscape level. The number of red list spiders and long-legged flies increased only with increasing core wetland area, while no significant effects were found for the number of red list ground beetles. Our study revealed that preserving or increasing the density of habitat corridors (more reed ditches) can be beneficial for the species richness of particular predatory arthropods, including species of conservation concern (especially ground beetles). Other groups react indifferently or are only positively impacted by an increase of core wetland area

Cannabidiol Protects Dopaminergic Neurons in Mesencephalic Cultures against the Complex I Inhibitor Rotenone Via Modulation of Heme Oxygenase Activity and Bilirubin

Phytocannabinoids protect neurons against stressful conditions, possibly via the heme oxygenase (HO) system. In cultures of primary mesencephalic neurons and neuroblastoma cells, we determined the capability of cannabidiol (CBD) and tetrahydrocannabinol (THC) to counteract effects elicited by complex I-inhibitor rotenone by analyzing neuron viability, morphology, gene expression of IL6, CHOP, XBP1, HO-1 (stress response), and HO-2, and in vitro HO activity. Incubation with rotenone led to a moderate stress response but massive degeneration of dopaminergic neurons (DN) in primary mesencephalic cultures. Both phytocannabinoids inhibited in-vitro HO activity, with CBD being more potent. Inhibition of the enzyme reaction was not restricted to neuronal cells and occurred in a non-competitive manner. Although CBD itself decreased viability of the DNs (from 100 to 78%), in combination with rotenone, it moderately increased survival from 28.6 to 42.4%. When the heme degradation product bilirubin (BR) was added together with CBD, rotenone-mediated degeneration of DN was completely abolished, resulting in approximately the number of DN determined with CBD alone (77.5%). Using N18TG2 neuroblastoma cells, we explored the neuroprotective mechanism underlying the combined action of CBD and BR. CBD triggered the expression of HO-1 and other cell stress markers. Co-treatment with rotenone resulted in the super-induction of HO-1 and an increased in-vitro HO-activity. Co-application of BR completely mitigated the rotenone-induced stress response. Our findings indicate that CBD induces HO-1 and increases the cellular capacity to convert heme when stressful conditions are met. Our data further suggest that CBD via HO may confer full protection against (oxidative) stress when endogenous levels of BR are sufficiently high

THE EFFECT OF SUBSTITUTION IN Nd2Fe14-xZxB (Z = Al, Si, Ga, Co, Ni) COMPOUNDS

Almost every element substituting Fe in Nd2Fe14B lowers the magnetocrystallined anisotropy. The effect on the ordering temperature Tc is different : in particular Al and Ni reduce Tc, whereas Si, Ga and Co increase Tc. Mössbauer experiments show that the Fe atoms are substituted in a non random manner. This is supported by the different magnetic properties due to the various substituents

Radical Scavenging Is Not Involved in Thymoquinone-Induced Cell Protection in Neural Oxidative Stress Models

Thymoquinone (TQ), an active compound from Nigella sativa seeds, is often described as a pharmacologically relevant compound with antioxidative properties, while the synthesis of TQ in the plant via oxidations makes it inapplicable for scavenging radicals. Therefore, the present study was designed to reassess the radical scavenging properties of TQ and explore a potential mode of action. The effects of TQ were studied in models with mitochondrial impairment and oxidative stress induced by rotenone in N18TG2 neuroblastoma cells and rotenone/MPP+ in primary mesencephalic cells. Tyrosine hydroxylase staining revealed that TQ significantly protected dopaminergic neurons and preserved their morphology under oxidative stress conditions. Quantification of the formation of superoxide radicals via electron paramagnetic resonance showed an initial increase in the level of superoxide radicals in the cell by TQ. Measurements in both cell culture systems revealed that the mitochondrial membrane potential was tendentially lowered, while ATP production was mostly unaffected. Additionally, the total ROS levels were unaltered. In mesencephalic cell culture under oxidative stress conditions, caspase-3 activity was decreased when TQ was administered. On the contrary, TQ itself tremendously increased the caspase-3 activity in the neuroblastoma cell line. Evaluation of the glutathione level revealed an increased level of total glutathione in both cell culture systems. Therefore, the enhanced resistance against oxidative stress in primary cell culture might be a consequence of a lowered caspase-3 activity combined with an increased pool of reduced glutathione. The described anti-cancer ability of TQ might be a result of the pro-apoptotic condition in neuroblastoma cells. Our study provides evidence that TQ has no direct scavenging effect on superoxide radicals