Cortical excitability signatures for the degree of sleepiness in human

Sleep is essential in maintaining physiological homeostasis in the brain. While the underlying mechanism is not fully understood, a 'synaptic homeostasis' theory has been proposed that synapses continue to strengthen during awake, and undergo downscaling during sleep. This theory predicts that brain excitability increases with sleepiness. Here, we collected transcranial magnetic stimulation (TMS) measurements in 38 subjects in a 34-hour program, and decoded the relationship between cortical excitability and self-report sleepiness using advanced statistical methods. By utilizing a combination of partial least squares (PLS) regression and mixed-effect models, we identified a robust pattern of excitability changes, which can quantitatively predict the degree of sleepiness. Moreover, we found that synaptic strengthen occurred in both excitatory and inhibitory connections after sleep deprivation. In sum, our study provides supportive evidence for the synaptic homeostasis theory in human sleep and clarifies the process of synaptic strength modulation during sleepiness.

Human Resource Risk Management Framework and Factors Influencing It

Nowadays, the importance of human resource risk in organizations has greatly increased, and some thinkers refer to it as a core competency and a key responsibility for any human resource professional. Thus, given the importance of the subject of the present article, the aim of this study is to analyze the human resource risk management framework and the factors influencing it. In this regard, using the library method, human resource risk framework was analyzed from the perspective of management science thinkers of Paul and Milcher, Ernst and Young, Meyer, Maenpaa & Voutilainen, Rotarsko, Li and Zhang, Pandey. Then, the factors influencing human resource risk management were identified and mentioned, and Stevens' human resource risk policies and procedures were presented. Then, the perception of risk and the factors influencing attention to risk and action for it were stated. In the final section, theories related to risk perception were discussed in the form of the Wild risk-homeostasis theory (1982) and the Naatanen & Summak zero-risk theory (1976). Studies show that human resource risk management frameworks provide a conceptual model for the systematic development and planning of human resource risk management activities. They are also useful for assessing and evaluating the level of human resource risk. These frameworks provide the basis for planning, evaluating, and implementing human resource risk management.

“God Spoke to Me”: Subjective Paranormal Experience and the Homeostatic Response to Early Trauma

The prevalence of reported subjective paranormal experience (SPE) is at high levels in all populations investigated to date. This article presents a new integrative theory of SPE in light of the brain’s homeostatic response to early trauma. I hold that developmental factors in the brain’s responses to trauma predispose victimized individuals towards SPE and paranormal beliefs. I examine the reported associations between childhood abuse, dissociation, depersonalization, compartmentalization, fantasy generation, homeostasis and SPE. A new integrative theory of psychological homeostasis draws upon the mechanisms of dissociation and fantasy generation to explain the origins of SPE. Twelve hypotheses from the Homeostasis Theory are found to be consistent with the findings of multiple studies and falsifying evidence has yet to be identified. Freezing and associated releases of fantasy, which may take the form of SPE, serve as a survival strategy in the homeostatic regaining of safety and control following childhood abuse. Prospective research is necessary to deepen our understanding of the brain mechanisms required by the system described here.

“God Spoke to Me”: Subjective Paranormal Experience and the Brain's Homeostatic Response to Early Trauma

Subjective paranormal experience (SPE) has been a notable part of the human historical narrative. Alleged miracles, telepathy, clairvoyance, precognition, witchcraft, spiritualism, monsters and ghosts have received a supernatural interpretation. The incidence and prevalence of reported SPE remains at high levels in all populations investigated to date. Previous research on SPE has focused on the cognitive and social factors that facilitate paranormal beliefs and experiences. I consider here developmental factors in the brain’s responses to trauma that appear to predispose certain individuals towards SPE. The theory draws upon the established mechanisms of dissociation and fantasy generation to describe and explain the origins of paranormal experience. The theory hypothesizes that childhood abuse and victimization trigger autonomic responses of dissociation, depersonalization and compartmentalization. Freezing and associated releases of fantasy serve as a survival strategy in the homeostatic regaining of safety and control. The predictions from the homeostasis theory are consistent with the findings of multiple studies and falsifying evidence has yet to be identified.

Stoichiometric homeostasis: a test to predict tundra vascular plant species and community-level responses to climate change

Climate change is having profound influences on Arctic tundra plant composition, community dynamics, and ecosystem processes. Stoichiometric homeostasis (H), the degree to which a plant maintains its internal nutrient concentrations independent of nutrient variations in its environment, may be a useful approach to predict the impacts of these influences. In this case study, we used fertilization manipulation data to calculate homeostasis indices based on nitrogen (HN), phosphorus (HP), and nitrogen to phosphorus ratios (HN:P) of aboveground tissues for seven common tundra vascular species belonging to three growth forms. We then analyzed species H relationships with dominance, spatial stability, and responsiveness to various experimental manipulations. Each of the H indices was correlated amongst tissue types within each species and was generally highest in ericoid mycorrhizal host species and lowest in the ectomycorrhizal birch. Species HP and HN:P were consistently positively correlated with aboveground biomass within the controls and across all manipulations. Furthermore, these same species were spatially stable across experimentally warmed field plots. Stoichiometric homeostasis theory has been successful in predicting grassland community dynamics. This first test of its applicability across a variety of Arctic plant growth forms highlights its considerable potential in predicting tundra plant community structure and responses to environmental change.

Maritime Safety Standards and the Seriousness of Shipping Accidents

In our paper The Risk Homeostasis Theory1, it was accepted that the behaviour of people involved in the operation of cargo carrying ships is conditioned to maximize the economic benefits of the amount of risk assumed in the transport. As a follow-up to that paper, the objective of this one is to investigate the relationship between the level of compliance of the cargo carrying vessels with international standards and the degree of severity of the incidents they are involved in. For this purpose, we analyse the same sample of 2,584 cargo carrying ships involved in incidents during 2005 and 2006 used in that investigation. The variables of the Paris MoU to identify substandard ships are used again to measure the standard level of ships and the degree of seriousness of incidents is determined by the number of days ships are under repair.