Spin-wave eigenmodes in direct-write 3D nanovolcanoes

Extending nanostructures into the third dimension has become a major research avenue in modern magnetism, superconductivity, and spintronics, because of geometry-, curvature-, and topology-induced phenomena. Here, we introduce Co-Fe nanovolcanoes-nanodisks overlaid by nanorings-as purpose-engineered 3D architectures for nanomagnonics, fabricated by focused electron beam-induced deposition. We use both perpendicular spin-wave resonance measurements and micromagnetic simulations to demonstrate that the rings encircling the volcano craters harbor the highest-frequency eigenmodes, while the lower-frequency eigenmodes are concentrated within the volcano crater, due to the non-uniformity of the internal magnetic field. By varying the crater diameter, we demonstrate the deliberate tuning of higher-frequency eigenmodes without affecting the lowest-frequency mode. Thereby, the extension of 2D nanodisks into the third dimension allows one to engineer their lowest eigenfrequency by using 3D nanovolcanoes with 30% smaller footprints. The presented nanovolcanoes can be viewed as multi-mode microwave resonators and 3D building blocks for nanomagnonics.O.V.D. and S.L.C. acknowledge the Austrian Science Fund (FWF) for support through Grant No. I 4889 (CurviMag). The Portuguese team acknowledges the Network of Extreme Conditions Laboratories-NECL and the Portuguese Foundation of Science and Technology (FCT) support through Project Nos. NORTE-01-0145-FEDER-022096, PTDC/FIS-MAC/31302/2017, POCI-0145-FEDER-030085 (NOVAMAG), and EXPL/IF/00541/2015. N. Z. and A. V. C. acknowledge the Austrian Science Fund (FWF) for support through Grant No. I 4917. S. B. acknowledges funding by the) Deutsche Forschungsgemeinschaft (DFG through Grant Nos. BA 6595/2-1 and BA 6595/1-1. K. G. acknowledges support from IKERBASQUE (the Basque Foundation for Science). The work of K. G. was supported by the Spanish Ministry of Science and Innovation through Grant No. PID2019-108075RB-C33/AEI/10.13039/501100011033. M.H. acknowledges the DFG for support through Grant No. HU 752/16-1. Support through the Frankfurt Center of Electron Microscopy (FCEM) is gratefully acknowledged. Further, support of the European Cooperation in Science and Technology via COST Action No. CA16218 (NANOCOHYBRI) is acknowledged

Benefits of adversity?! How life history affects the behavioral profile of mice varying in serotonin transporter genotype

Behavioral profiles are influenced by both positive and negative experiences as well as the genetic disposition. Traditionally, accumulating adversity over lifetime is considered to predict increased anxiety-like behavior (“allostatic load”). The alternative “mismatch hypothesis” suggests increased levels of anxiety if the early environment differs from the later-life environment. Thus, there is a need for a whole-life history approach to gain a deeper understanding of how behavioral profiles are shaped. The aim of this study was to elucidate the effects of life history on the behavioral profile of mice varying in serotonin transporter (5-HTT) genotype, an established mouse model of increased anxiety-like behavior. For this purpose, mice grew up under either adverse or beneficial conditions during early phases of life. In adulthood, they were further subdivided so as to face a situation that either matched or mismatched the condition experienced so far, resulting in four different life histories. Subsequently, mice were tested for their anxiety-like and exploratory behavior. The main results were: (1) Life history profoundly modulated the behavioral profile. Surprisingly, mice that experienced early beneficial and later escapable adverse conditions showed less anxiety-like and more exploratory behavior compared to mice of other life histories. (2) Genotype significantly influenced the behavioral profile, with homozygous 5-HTT knockout mice displaying highest levels of anxiety-like and lowest levels of exploratory behavior. Our findings concerning life history indicate that the absence of adversity does not necessarily cause lower levels of anxiety than accumulating adversity. Rather, some adversity may be beneficial, particularly when following positive events. Altogether, we conclude that for an understanding of behavioral profiles, it is not sufficient to look at experiences during single phases of life, but the whole life history has to be considered

Engineered magnetization and exchange stiffness in direct-write Co-Fe nanoelements

Media with engineered magnetization are essential building blocks in superconductivity, magnetism and magnon spintronics. However, the established thin-film and lithographic techniques insufficiently suit the realization of planar components with on-demand-tailored magnetization in the lateral dimension. Here, we demonstrate the engineering of the magnetic properties of CoFe-based nanodisks fabricated by the mask-less technique of focused electron beam induced deposition (FEBID). The material composition in the nanodisks is tuned \emph{in-situ} via the e-beam waiting time in the FEBID process and their post-growth irradiation with Ga ions. The magnetization $M_s$ and exchange stiffness $A$ of the disks are deduced from perpendicular ferromagnetic resonance measurements. The achieved $M_s$ variation in the broad range from $720$ emu/cm$^3$ to $1430$ emu/cm$^3$ continuously bridges the gap between the $M_s$ values of such widely used magnonic materials as permalloy and CoFeB. The presented approach paves a way towards nanoscale 2D and 3D systems with controllable and space-varied magnetic properties.Comment: 5 pages, 4 figure

Effects of the social environment during adolescence on the development of social behaviour, hormones and morphology in male zebra finches (Taeniopygia guttata)

Abstract Background Individual differences in behaviour are widespread in the animal kingdom and often influenced by the size or composition of the social group during early development. In many vertebrates the effects of social interactions early in life on adult behaviour are mediated by changes in maturation and physiology. Specifically, increases in androgens and glucocorticoids in response to social stimulation seem to play a prominent role in shaping behaviour during development. In addition to the prenatal and early postnatal phase, adolescence has more recently been identified as an important period during which adult behaviour and physiology are shaped by the social environment, which so far has been studied mostly in mammals. We raised zebra finches ( Taeniopygia guttata ) under three environmental conditions differing in social complexity during adolescence\ua0-\ua0juvenile pairs, juvenile groups, and mixed-age groups - and studied males\u2019 behavioural, endocrine, and morphological maturation, and later their adult behaviour. Results As expected, group-housed males exhibited higher frequencies of social interactions. Group housing also enhanced song during adolescence, plumage development, and the frequency and intensity of adult courtship and aggression. Some traits, however, were affected more in juvenile groups and others in mixed-age groups. Furthermore, a testosterone peak during late adolescence was suppressed in groups with adults. In contrast, corticosterone concentrations did not differ between rearing environments. Unexpectedly, adult courtship in a test situation was lowest in pair-reared males and aggression depended upon the treatment of the opponent with highest rates shown by group-reared males towards pair-reared males. This contrasts with previous findings, possibly due to differences in photoperiod and the acoustic environment. Conclusion Our results support the idea that effects of the adolescent social environment on adult behaviour in vertebrates are mediated by changes in social interactions affecting behavioural and morphological maturation. We found no evidence that long-lasting differences in behaviour reflect testosterone or corticosterone levels during adolescence, although differences between juvenile and mixed-age groups suggest that testosterone and song behaviour during late adolescence may be associated

The predictive value of early behavioural assessments in pet dogs: a longitudinal study from neonates to adults

Studies on behavioural development in domestic dogs are of relevance for matching puppies with the right families, identifying predispositions for behavioural problems at an early stage, and predicting suitability for service dog work, police or military service. The literature is, however, inconsistent regarding the predictive value of tests performed during the socialisation period. Additionally, some practitioners use tests with neonates to complement later assessments for selecting puppies as working dogs, but these have not been validated. We here present longitudinal data on a cohort of Border collies, followed up from neonate age until adulthood. A neonate test was conducted with 99 Border collie puppies aged 2–10 days to assess activity, vocalisations when isolated and sucking force. At the age of 40–50 days, 134 puppies (including 93 tested as neonates) were tested in a puppy test at their breeders' homes. All dogs were adopted as pet dogs and 50 of them participated in a behavioural test at the age of 1.5 to 2 years with their owners. Linear mixed models found little correspondence between individuals' behaviour in the neonate, puppy and adult test. Exploratory activity was the only behaviour that was significantly correlated between the puppy and the adult test. We conclude that the predictive validity of early tests for predicting specific behavioural traits in adult pet dogs is limited

Excretion patterns of coccidian oocysts and nematode eggs during the reproductive season in Northern Bald Ibis (Geronticus eremita)

Individual reproductive success largely depends on the ability to optimize behaviour, immune function and the physiological stress response. We have investigated correlations between behaviour, faecal steroid metabolites, immune parameters, parasite excretion patterns and reproductive output in a critically endangered avian species, the Northern Bald Ibis (Geronticus eremita). In particular, we related haematocrit, heterophil/lymphocyte ratio, excreted immune-reactive corticosterone metabolites and social behaviour with parasite excretion and two individual fitness parameters, namely, number of eggs laid and number of fledglings. We found that the frequency of excretion of parasites’ oocysts and eggs tended to increase with ambient temperature. Paired individuals excreted significantly more samples containing nematode eggs than unpaired ones. The excretion of nematode eggs was also significantly more frequent in females than in males. Individuals with a high proportion of droppings containing coccidian oocysts were more often preened by their partners than individuals with lower excretion rates. We observed that the more eggs an individual incubated and the fewer offspring fledged, the higher the rates of excreted samples containing coccidian oocysts. Our results confirm that social behaviour, physiology and parasite burden are linked in a complex and context-dependent manner. They also contribute background information supporting future conservation programmes dealing with this critically endangered species