Magnetically sensitive light-induced reactions in cryptochrome are consistent with its proposed role as a magnetoreceptor

Among the biological phenomena that fall within the emerging field of "quantum biology" is the suggestion that magnetically sensitive chemical reactions are responsible for the magnetic compass of migratory birds. It has been proposed that transient radical pairs are formed by photo-induced electron transfer reactions in cryptochrome proteins and that their coherent spin dynamics are influenced by the geomagnetic field leading to changes in the quantum yield of the signaling state of the protein. Despite a variety of supporting evidence, it is still not clear whether cryptochromes have the properties required to respond to magnetic interactions orders of magnitude weaker than the thermal energy, k(B)T. Here we demonstrate that the kinetics and quantum yields of photo-induced flavin-tryptophan radical pairs in cryptochrome are indeed magnetically sensitive. The mechanistic origin of the magnetic field effect is clarified, its dependence on the strength of the magnetic field measured, and the rates of relevant spin-dependent, spin-independent, and spin-decoherence processes determined. We argue that cryptochrome is fit for purpose as a chemical magnetoreceptor.     

Wnt/β-catenin signaling is downregulated but restored by nutrition interventions in the aged heart in mice

Aging hallmarks include decreased progenitor cell functions. The Wnt/β-catenin signaling pathway has emerged as a key player in cellular aging in recent years. Wnt activity changes in aged tissues including skin, serum, muscle and artery. In heart, it is hypothesized that Wnt signaling increases with aging and this signaling drives cardiac progenitor cells into fibrogenic lineage. However, experimental evidence supporting this hypothesis has not been established. Here we take a bioinformatics data mining approach, utilizing pre-existing data, to study cardiac aging gene expression data in mice. Contrary to the hypothesis, our study shows that the Wnt/β-catenin signaling is down-regulated in aged heart in mice. Nutrition treatment, with calorie restriction and Resveratrol supplementation, known to retard aging, opposes heart aging by restoring Wnt/β-catenin signaling level in the old heart. In addition, the expression of β-catenin gene, a key regulator of the Wnt/β-catenin signaling pathway, decreases up to 3-fold in aged heart, but is restored to levels found in young heart with methods of nutrition intervention. Combined with database search, our study suggests that some of bioflavonoids may have potential therapeutic benefits to heart aging.     

Appetitive Violence: A New Phenomenon?

Youth violence has long been regarded as a major social issue. The past decade has, however, seen the scrutiny which encompasses this violence intensify, largely due to a recent media focus on an apparently increasing tendency amongst some young people to engage in acts of ‘appetitive’ or ‘thrill-seeking’ violence. This is reported to be a new form of violence, in which young people act in an excitable state, rather than the more common form of anger-mediated violence. Whilst incidents of appetitive violence are overly represented in the news media and are presented as a major public concern, there is presently no empirical research exploring the validity of this phenomenon and no systematic analysis of the frequency and severity of this form of violent behaviour. Furthermore, the underlying causes of this type of violence are not understood. As such, preventative practices, risk assessment, treatment requirements and targeted management strategies are lacking. The purpose of this review is to examine the current literature on youth violence, particularly youth involvement in ‘thrill-seeking’ acts of violence, as well as describing a range of contemporary factors highlighted as integral to youth violence; specifically, gang involvement, alcohol use and the possession of weapons. This review will also examine an array of international strategies implemented in response to this form of youth violence. Finally, the General Aggression Model (GAM) will be considered to determine whether its framework can assist in advancing our understanding of appetitive violence, by elucidating those characteristics of the individual and their environment that contribute to its expression.     

Verbal adynamia in parkinsonian syndromes: behavioral correlates and neuroanatomical substrate

ABSTRACT

Verbal adynamia (impaired language generation, as during conversation) has not been assessed systematically in parkinsonian disorders. We addressed this in patients with Parkinson’s dementia, progressive supranuclear palsy and corticobasal degeneration. All disease groups showed impaired verbal fluency and sentence generation versus healthy age-matched controls, after adjusting for general linguistic and executive factors. Dopaminergic stimulation in the Parkinson’s group selectively improved verbal generation versus other cognitive functions. Voxel-based morphometry identified left inferior frontal and posterior superior temporal cortical correlates of verbal generation performance. Verbal adynamia warrants further evaluation as an index of language network dysfunction and dopaminergic state in parkinsonian disorders.     

One-Month Serotonin Infusion Results in a Prolonged Fall in Blood Pressure in the Deoxycorticosterone Acetate (DOCA) Salt Hypertensive Rat

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