Detection of potential space station control/structure interaction with CO-ST-IN

The NASA Lewis Research Center is concerned with the potential of interaction between space station controllers and the solar PV array structures. The models required to handle this problem are very large, and automated methods were developed for the transfer of data between structural dynamic and control system analysis software. These methods emphasize the need to achieve accurate coupled analysis results while using as small a model as possible. Specific tools which help the analyst in this regard include modal order techniques, the use of mode acceleration to calculate internal loads and stresses and the transfer of Craig-Bampton components to reduce problems associated with modal sufficiency. These techniques were applied to a space station model with 366 modes below 1 Hz. Attitude control, and alpha and beta joint control were simulated. The inclusion of alpha and beta joint controllers is important when examining overall space station dynamics. An initial choice of control parameters does indicate a potential for control/structure interaction during reboost. As expected this is exacerbated by increasing the rate gain and decreasing the hysteresis of the reaction control system (RCS) in order to improve rigid body performance

Which combination drug therapies are most effective for hypertension?

Insufficient evidence exists to determine which specific combinations most effectively decrease cardiovascular morbidity and mortality, although combinations of hypertension medications at lower doses generally reduce cardiovascular outcomes (stroke, coronary heart disease) more than monotherapy (strength of recommendation [SOR]: A, large meta-analyses). The combination of benazepril and amlodipine reduces the composite endpoint of cardiovascular events and deaths more than benazepril plus hydrochlorothiazide with similar rates of adverse effects (SOR: A, randomized controlled trial [RCT]). Combining an angiotensin converting enzyme inhibitor (ACE-I) with a thiazide, b-blocker, or calcium channel blocker produces side effects similar to monotherapy, as does combining an angiotensin receptor blocker (ARB) with a thiazide or calcium channel blocker (SOR: A, meta-analyses). However, an ACE-I combined with an ARB increases the risk of renal complications and death more than monotherapy (SOR: A, RCT)

Chronobiology of Epilepsy

A fine balance between neuronal excitation and inhibition governs the physiological state of the brain. It has been hypothesized that when this balance is lost as a result of excessive excitation or reduced inhibition, pathological states such as epilepsy emerge. Decades of investigation have shown this to be true in vitro. However, in vivo evidence of the emerging imbalance during the "latent period" between the initiation of injury and the expression of the first spontaneous behavioral seizure has not been demonstrated. Here, we provide the first demonstration of this emerging imbalance between excitation and inhibition in vivo by employing long term, high temporal resolution, and continuous local field recordings from microelectrode arrays implanted in an animal model of limbic epilepsy. We were able to track both the inhibitory and excitatory postsynaptic field activity during the entire latent period, from the time of injury to the occurrence of the first spontaneous epileptic seizure. During this latent period we observe a sustained increase in the firing rate of the excitatory postsynaptic field activity, paired with a subsequent decrease in the firing rate of the inhibitory postsynaptic field activity within the CA1 region of the hippocampus. Firing rates of both excitatory and inhibitory CA1 field activities followed a circadian- like rhythm, which is locked near in-phase in controls and near anti-phase during the latent period. We think that these observed changes are implicated in the occurrence of spontaneous seizure onset following injury

Naturopathic Physician Attitudes and Practices for Vaccination and Primary Care in the State of Vermont

Introduction: Recent increase in measles cases has sparked vaccination controversy. Naturopathic physicians (NDs) have been recognized as primary care providers by VT since 2012. It is not well understood how NDs address vaccination with patients. Our goal was to determine how Vermont NDs address vaccines and preventative care with their patients.https://scholarworks.uvm.edu/comphp_gallery/1234/thumbnail.jp

Dermal fin rays and scales derive from mesoderm, not neural crest

SummaryNeural crest cells disperse throughout the embryonic head to generate diverse cell types of two classes: non-ectomesenchymal (including melanocytes, peripheral neurons and glia) and ectomesenchymal (skeletogenic, odontogenic, cartilaginous and connective tissue cell fates). In contrast to cranial neural crest, trunk neural crest of amniotes generates only non-ectomesenchymal cell types. Anamniote trunk neural crest, however, has been assumed to generate derivatives of both classes, including osteoblasts of dermal skeletal elements, which includes scales and fin rays. Through genetic lineage tracing in zebrafish, we present the first test of this assumption and find that trunk neural crest does not generate fin osteoblasts; rather, these derive from a late emerging population of paraxial mesoderm. Similarly we show that the mineralising cells of the scales are mesodermally derived, with no contribution from neural crest. Our data suggest that trunk/tail exoskeletal structures evolved through deployment of mesodermally derived mesenchyme, rather than neural crest

Structures of Receptor Complexes of a North American H7N2 Influenza Hemagglutinin with a Loop Deletion in the Receptor Binding Site

Human infections with subtype H7 avian influenza viruses have been reported as early as 1979. In 1996, a genetically stable 24-nucleotide deletion emerged in North American H7 influenza virus hemagglutinins, resulting in an eight amino acid deletion in the receptor-binding site. The continuous circulation of these viruses in live bird markets, as well as its documented ability to infect humans, raises the question of how these viruses achieve structural stability and functionality. Here we report a detailed molecular analysis of the receptor binding site of the North American lineage subtype H7N2 virus A/New York/107/2003 (NY107), including complexes with an avian receptor analog (3′-sialyl-N-acetyllactosamine, 3′SLN) and two human receptor analogs (6′-sialyl-N-acetyllactosamine, 6′SLN; sialyllacto-N-tetraose b, LSTb). Structural results suggest a novel mechanism by which residues Arg220 and Arg229 (H3 numbering) are used to compensate for the deletion of the 220-loop and form interactions with the receptor analogs. Glycan microarray results reveal that NY107 maintains an avian-type (α2-3) receptor binding profile, with only moderate binding to human-type (α2-6) receptor. Thus despite its dramatically altered receptor binding site, this HA maintains functionality and confirms a need for continued influenza virus surveillance of avian and other animal reservoirs to define their zoonotic potential

Pilot Source Study 2015: US Regional Airline Pilot Hiring Background Characteristic Changes Consequent to Public Law 111-216 and the FAA First Officer Qualifications Rule

This report is the first article in a series called Pilot Source Study 2015. Public Law (PL) 111-216, passed by the US Congress in 2010, and the subsequent FAA Regulation, Pilot Certification and Qualification Requirements for Air Carrier Operations Rule, abruptly changed the pilot hiring situation for US air carriers operating under 14 CFR Part 121. PL 111-216 became effective on August 1, 2013; thereafter, pilots were not eligible to be first officers in Part 121 air carriers unless they were certificated as Air Transport Pilots (ATP) with 1,500 hours of flight time, with some flight hour reductions for specified military and academic experiences. Recognizing that the rule had a notable impact on US regional airlines, the researchers visited 19 Part 121 regional airlines to extract data from their documents and records. De-identified background and corresponding performance data were recorded for 6,734 pilots hired after August 1, 2013. These data were analyzed in three articles, exploring the background characteristics of these pilots and determining to what extent there were differences in these background characteristics between post-law pilots (hired after August 1, 2013) and pre-law pilots (hired from 2005 to 2011). Besides the mandated increase in total flight hours and the requirement for an ATP certificate, the post-law pilots had less aviation-related academic experience, a lower proportion of flight instructors with more instructor experience, a larger proportion of military pilots, and a large range of flight experience suggesting career switching or returning to aviation. Among pilots with less experience, there was a significant reduction in multiengine time. This report is a preliminary article on the shift of pilot background characteristics as a result of the pilot certification and qualifications requirements mandated by Congress. Two future articles are being prepared. One article will analyze the success of post-law pilots in initial training for Part 121 operations, and another article will compare background and success factors between pilots hired before PL 111-216 and those hired after the law was passed

Pilot Source Study 2015: An Analysis of FAR Part 121 Pilots Hired after Public Law 111-216—Their Backgrounds and Subsequent Successes in US Regional Airline Training and Operating Experience

This report is the second in a series entitled Pilot Source Study 2015. Public Law 111-216 (Airline Safety and Federal Aviation Administration Extension Act of 2010) and the subsequent FAA regulation changed pilot hiring for US air carriers operating under 14 CFR Part 121. The Pilot Source Study 2015 was designed to determine the effect of Public Law 111-216 on US regional airlines after its effective date, August 1, 2013. The study collected records for 6,734 FAR Part 121 regional airline pilots to determine the effect of pilots’ backgrounds on their performance in regional airline training and operations. A previous report (Bjerke et al., 2016) compared the backgrounds of these pilots (post-law pilots) to the backgrounds of pilots hired between 2005 and 2011 (pre-law pilots). This report examines the performance of post-law new-hire pilots in initial training and operations as first officers for Part 121 regional air carriers. Post-law pilot backgrounds were measured against four performance measures: non-completions, extra training, extra initial operating experience (IOE), and extra recurrent training. Pilots who had the fewest non-completions and required less extra training were the recent college graduates (fewer than 4 years since graduation), pilots with fewer total flight hours (1,500 hours or less), and pilots who graduated from flight programs accredited by the Aviation Accreditation Board International (AABI). Pilots who required less extra IOE and less extra recurrent training were pilots whose previous employment was with a Part 121 air carrier, recent college graduates (fewer than 4 years since graduation), and pilots with fewer total flight hours (1,500 hours or less). Other background indicators of successful performance included the Institutional-Authority Restricted ATP (R-ATP); a bachelor’s degree, particularly in aviation; and prior military pilot experience. The third report of this series will compare background and success factors between pre-law pilots and post-law pilots