Frank to Jim, 24 July 1956

Professional correspondenc

Impact of axial active magnetic bearing stiffness coefficient on resonance frequencies of reaction wheel rotor

Разработана математическая модель системы «ротор - электромагнитные подшипники» для электродвигателя-маховика системы ориентации и стабилизации космического аппарата. Модель учитывает собственные частоты изгибных колебаний ротора и коэффициенты жесткости электромагнитных подшипников. Предложен способ повышения угловой жесткости системы путем применения многополюсного осевого электромагнитного подшипника и рассмотрено влияние его коэффициента жесткости на собственные частоты системы.The paper presents the mathematical model of «rotor - active magnetic bearings» system for reaction wheel used in spacecraft attitude control system. Developed model consider the natural frequencies of rotor bending oscillations and stiffness parameters of electromagnetic bearing. Method of angular stiffness increasing by using multipolar axial magnetic bearing is suggested and the results of impact analysis of multipolar axial magnetic bearing stiffness on resonance frequencies of system is considered

Working memory filtering continues to develop into late adolescence

While most measures of working memory (WM) performance have been shown to plateau by mid-adolescence and developmental changes in fronto-parietal regions supporting WM encoding and maintenance have been well characterized, little is known about developmental variation in WM filtering. We investigated the possibility that the neural underpinnings of filtering in WM reach maturity later in life than WM function without filtering. Using a cued WM filtering task (McNab and Klingberg, 2008), we investigated neural activity during WM filtering in a sample of 64 adults and adolescents. Regardless of age, increases in WM activity with load were concentrated in the expected fronto-parietal network. For adults, but not adolescents, recruitment of the basal ganglia during presentation of a filtering cue was associated with neural and behavioral indices of successful filtering, suggesting that WM filtering and related basal ganglia function may still be maturing throughout adolescence and into adulthood

A genomic lifespan program that reorganises the young adult brain is targeted in schizophrenia

The genetic mechanisms regulating the brain and behaviour across the lifespan are poorly understood. We found that lifespan transcriptome trajectories describe a calendar of gene regulatory events in the brain of humans and mice. Transcriptome trajectories defined a sequence of gene expression changes in neuronal, glial and endothelial cell-types, which enabled prediction of age from tissue samples. A major lifespan landmark was the peak change in trajectories occurring in humans at 26 years and in mice at 5 months of age. This species-conserved peak was delayed in females and marked a reorganization of expression of synaptic and schizophreniasusceptibility genes. The lifespan calendar predicted the characteristic age of onset in young adults and sex differences in schizophrenia. We propose a genomic program generates a lifespan calendar of gene regulation that times age-dependent molecular organization of the brain and mutations that interrupt the program in young adults cause schizophrenia

Training Basic Visual Attention Leads to Changes in Responsiveness to Social‐Communicative Cues in 9‐Month‐Olds

The current study investigated transfer effects of gaze-interactive attention training to more complex social and cognitive skills in infancy. Seventy 9-month-olds were assigned to a training group (n = 35) or an active control group (n =35). Before, after, and at 6-week follow-up both groups completed an assessment battery assessing transfer to non-trained aspects of attention control, including table-top tasks assessing social attention in semi-naturalistic contexts. Transfer effects were found on non-trained screen-based tasks, but importantly also on a structured observation task assessing the infants’ likelihood to respond to an adult’s social communication cues. The results causally link basic attention skills and more complex social communicative skills, and provide a principle for studying causal mechanisms of early development

Cyclical Trends in American Foreign Policy Moods

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