Use of Incremental Adaptation and Habituation Regimens for Mitigating Optokinetic Side-effects

The use of incremental and repeated exposures regimens have been put forth as effective means to mitigate visually induced motion sickness based on the Dual Process Theory (DPT) (Groves & Thompson, 1970) of neural plasticity. In essence, DPT suggests that by incrementing stimulus intensity the depression opponent process should be allowed to exert greater control over the net outcome than the sensitization opponent process, thereby minimizing side-effects. This conceptual model was tested by empirically validating the effectiveness of adaptation, incremental adaptation, habituation, and incremental habituation regimens to mitigate side-effects arising from exposure to an optokinetic drum. Forty college students from the University of Central Florida participated in the experimentation and were randomly assigned to a regimen. Efforts were taken to balance distribution of participants in the treatments for gender and motion sickness susceptibility. Results indicated that overall, the application of an incremental regimen is effective in reducing side-effects (e.g. malaise, dropout rates, postural instabilities, etc.) when compared to a non-incremented regimen, whether it be a one-time or repeated exposure. Furthermore, the application of the Motion History Questionnaire (MHQ) (Graybiel & Kennedy, 1965) for identifying high and low motion sickness susceptible individuals proved effective. Finally, gender differences in motion sickness were not found in this experiment as a result of balancing susceptibility with the gender subject variable. Findings from this study can be used to aid effective design of virtual environment (VE) usage regimens in an effort to manage cybersickness. Through pre-exposure identification of susceptible individuals via the MHQ, exposure protocols can be devised that may extend limits on exposure durations, mitigate side-effects, reduce dropout rates, and possibly increase training effectiveness. This document contains a fledgling set of guidelines form VE usage that append those under development by Stanney, Kennedy, & Kingdon (In press) and other previously established guidelines form simulator use (Kennedy et al., 1987). It is believed that through proper allocation of effective VE usage regimens cybersickness can be managed, if susceptible individuals are identified prior to exposure

Crew factors in flight operations 9: Effects of planned cockpit rest on crew performance and alertness in long-haul operations

This study examined the effectiveness of a planned cockpit rest period to improve alertness and performance in long-haul flight operations. The Rest Group (12 crew members) was allowed a planned 40 minute rest period during the low workload, cruise portion of the flight, while the No-Rest Group (9 crew members) had a 40 minute planned control period when they maintained usual flight activities. Measures used in the study included continuous ambulatory recordings of brain wave and eye movement activity, a reaction time/vigilance task, a wrist activity monitor, in-flight fatigue and alertness ratings, a daily log for noting sleep periods, meals, exercise, flight and duty periods, and the NASA Background Questionnaire. The Rest Group pilots slept on 93 percent of the opportunities, falling asleep in 5.6 minutes and sleeping for 25.8 minutes. This nap was associated with improved physiological alertness and performance compared to the No-Rest Group. The benefits of the nap were observed through the critical descent and landing phases of flight. The nap did not affect layover sleep or the cumulative sleep debt. The nap procedures were implemented with minimal disruption to usual flight operations and there were no reported or identified concerns regarding safety

Multi-omics of the gut microbial ecosystem in inflammatory bowel diseases.

Inflammatory bowel diseases, which include Crohn's disease and ulcerative colitis, affect several million individuals worldwide. Crohn's disease and ulcerative colitis are complex diseases that are heterogeneous at the clinical, immunological, molecular, genetic, and microbial levels. Individual contributing factors have been the focus of extensive research. As part of the Integrative Human Microbiome Project (HMP2 or iHMP), we followed 132 subjects for one year each to generate integrated longitudinal molecular profiles of host and microbial activity during disease (up to 24 time points each; in total 2,965 stool, biopsy, and blood specimens). Here we present the results, which provide a comprehensive view of functional dysbiosis in the gut microbiome during inflammatory bowel disease activity. We demonstrate a characteristic increase in facultative anaerobes at the expense of obligate anaerobes, as well as molecular disruptions in microbial transcription (for example, among clostridia), metabolite pools (acylcarnitines, bile acids, and short-chain fatty acids), and levels of antibodies in host serum. Periods of disease activity were also marked by increases in temporal variability, with characteristic taxonomic, functional, and biochemical shifts. Finally, integrative analysis identified microbial, biochemical, and host factors central to this dysregulation. The study's infrastructure resources, results, and data, which are available through the Inflammatory Bowel Disease Multi'omics Database ( http://ibdmdb.org ), provide the most comprehensive description to date of host and microbial activities in inflammatory bowel diseases

Occupy: in theory and practice

This paper situates the discourse of the Occupy movement within the context of radical political philosophy. Our analysis takes place on two levels. First, we conduct an empirical analysis of the ‘official’ publications of Occupy Wall Street (OWS) and Occupy London (OL). Operationalising core concepts from the framing perspective within social movement theory, we provide a descriptive-comparative analysis of the ‘collective action frames’ of OWS and OL. Second, we consider the extent to which radical political philosophy speaks to the discourse of Occupy. Our empirical analysis reveals that both movements share diagnostic frames, but there were notable differences in terms of prognostic framing. The philosophical discussion suggests that there are alignments between anarchist, post-anarchist and post-Marxist ideologies at the level of both identity and strategy. Indeed, the absence of totalising anti-capitalist or anti-statist positions in Occupy suggests that – particularly with Occupy London – alignments are perhaps not so distant from typically social democratic demands

Macrophages in Alzheimer’s disease: the blood-borne identity

Alzheimer’s disease (AD) is a progressive and incurable neurodegenerative disorder clinically characterized by cognitive decline involving loss of memory, reasoning and linguistic ability. The amyloid cascade hypothesis holds that mismetabolism and aggregation of neurotoxic amyloid-β (Aβ) peptides, which are deposited as amyloid plaques, are the central etiological events in AD. Recent evidence from AD mouse models suggests that blood-borne mononuclear phagocytes are capable of infiltrating the brain and restricting β-amyloid plaques, thereby limiting disease progression. These observations raise at least three key questions: (1) what is the cell of origin for macrophages in the AD brain, (2) do blood-borne macrophages impact the pathophysiology of AD and (3) could these enigmatic cells be therapeutically targeted to curb cerebral amyloidosis and thereby slow disease progression? This review begins with a historical perspective of peripheral mononuclear phagocytes in AD, and moves on to critically consider the controversy surrounding their identity as distinct from brain-resident microglia and their potential impact on AD pathology

Modes of Aβ toxicity in Alzheimer’s disease

Alzheimer’s disease (AD) is reaching epidemic proportions, yet a cure is not yet available. While the genetic causes of the rare familial inherited forms of AD are understood, the causes of the sporadic forms of the disease are not. Histopathologically, these two forms of AD are indistinguishable: they are characterized by amyloid-β (Aβ) peptide-containing amyloid plaques and tau-containing neurofibrillary tangles. In this review we compare AD to frontotemporal dementia (FTD), a subset of which is characterized by tau deposition in the absence of overt plaques. A host of transgenic animal AD models have been established through the expression of human proteins with pathogenic mutations previously identified in familial AD and FTD. Determining how these mutant proteins cause disease in vivo should contribute to an understanding of the causes of the more frequent sporadic forms. We discuss the insight transgenic animal models have provided into Aβ and tau toxicity, also with regards to mitochondrial function and the crucial role tau plays in mediating Aβ toxicity. We also discuss the role of miRNAs in mediating the toxic effects of the Aβ peptide