286 research outputs found
Current-induced spin torque resonance of magnetic insulators affected by field-like spin-orbit torques and out-of-plane magnetizations
The spin-torque ferromagnetic resonance (ST-FMR) in a bilayer system
consisting of a magnetic insulator such as Y3Fe5O12 and a normal metal with
spin-orbit interaction such as Pt is addressed theoretically. We model the
ST-FMR for all magnetization directions and in the presence of field-like
spin-orbit torques based on the drift-diffusion spin model and quantum
mechanical boundary conditions. ST-FMR experiments may expose crucial
information about the spin-orbit coupling between currents and magnetization in
the bilayers.Comment: 4 pages, 2 figure
Coercion promotes alloparental care in cooperative breeders.
Members of social groups may negotiate among each other about the exchange of goods and services. If this involves asymmetries between interacting partners, for instance in condition, power, or expected payoffs, coercion may be involved in the bargain. Cooperative breeders are excellent models to study such interactions, because asymmetries are inherent in the relationship between dominant breeders and subordinate helpers. Currently it is unclear whether punishment is used to enforce costly cooperation in such systems. Here we investigated experimentally in the cooperatively breeding cichlid Neolamprologus pulcher whether alloparental brood care provided by subordinates is contingent on enforcement by dominant breeders. We manipulated first the brood care behavior of a subordinate group member and then the possibility of the dominant breeders to punish idle helpers. When subordinates were prevented from providing brood care, breeders increased their attacks on them, which triggered increased alloparental brood care by helpers as soon as this was again possible. In contrast, when the possibility to punish helpers was prevented, energetically costly alloparental brood care did not increase. Our results confirm predictions of the pay-to-stay mechanism causing alloparental care in this species and they suggest more generally that coercion can play an important role in the control of cooperation
Mineralocorticoid receptors in nonâalcoholic fatty liver disease
Liver diseases are the fourth common death in Europe responsible for about 2 million death per year worldwide. Among the known detrimental causes for liver dysfunction are virus infections, intoxications and obesity. The mineralocorticoid receptor (MR) is a ligandâdependent transcription factor activated by aldosterone or glucocorticoids but also by pathological milieu factors. Canonical actions of the MR take place in epithelial cells of kidney, colon and sweat glands and contribute to sodium reabsorption, potassium secretion and extracellular volume homeostasis. The nonâcanonical functions can be initiated by inflammation or an altered microâmilieu leading to fibrosis, hypertrophy and remodelling in various tissues. This narrative review summarizes the evidence regarding the role of MR in portal hypertension, nonâalcoholic fatty liver disease, liver fibrosis and cirrhosis, demonstrating that inhibition of the MR in vivo seems to be beneficial for liver function and not just for volume regulation. Unfortunately, the underlying molecular mechanisms are still not completely understood
An all-electrical torque differential magnetometer operating under ambient conditions
An all-electrical torque differential magnetometry (also known as cantilever
magnetometry) setup employing piezoelectric quartz tuning forks is
demonstrated. The magnetometer can be operated under ambient conditions as well
as low temperatures and pressures. It extends the allowed specimen mass range
up to several 10 g without any significant reduction in the sensitivity.
Operation under ambient conditions and a simple all-electrical design of the
magnetometer should allow for an easy integration with other experimental
setups. The uniaxial magnetic anisotropy of a 25 m diameter iron wire,
measured under ambient conditions with a high signal to noise ratio, was found
to be in good agreement with its literature value. Further applications of the
technique are discussed.Comment: 9 two-column pages, 9 figure
Authors reply to Mushtaq and Minn-Dinâs letter [Anxiety disorders in mothers and their children : prospective-longitudinal community study]
As Mushtaq & Minn-Din correctly point out, Bijl et al1 did not find associations between prevalence rates of any psychiatric disorder (including anxiety disorders) in children and anxiety-related symptoms in parents. However, one must be aware of several methodological differences to our investigation: the results cited by Mushtaq & Minn-Din are based on 12-month prevalence rates and multivariate logistic regression analysis additionally controlling for childhood adversities and socio-demographic characteristics. We would like to clarify that the results of the Bijl et al paper are much more comparable with our study and that the results we are actually referring to are those based on life-time prevalence rates of psychiatric disorders in children without controlling for childhood adversities and reported separately for the various offspring disorders. Here, Bijl et al clearly report associations between anxiety in parents and children. In addition, it is true that the adult children in the Bijl et al study were considerably older (18â65 years) than the offspring in our study (17â21 years at follow-up). We would like to add that there are other substantial ways in which the studies differ; for example, our use of assessment via direct interviews v. family-history information.1 Nevertheless, we do not see why our claim that we confirm and extend the Bijl et al study should be problematic, especially when taking into account the low median for age at onset of anxiety disorders.2 We would also like to point out that both studies were community-based so that the use of the term âpatientsâ by Mushtaq & Minn-Din is slightly misleading
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