The Plasma Interaction Experiment (PIX) description and test program

The plasma interaction experiment (PIX) is a battery powered preprogrammed auxiliary payload on the LANDSAT-C launch. This experiment is part of a larger program to investigate space plasma interactions with spacecraft surfaces and components. The varying plasma densities encountered during available telemetry coverage periods are deemed sufficient to determine first order interactions between the space plasma environment and the biased experimental surfaces. The specific objectives of the PIX flight experiment are to measure the plasma coupling current and the negative voltage breakdown characteristics of a solar array segment and a gold plated steel disk. Measurements will be made over a range of surface voltages up to plus or minus kilovolt. The orbital environment will provide a range of plasma densities. The experimental surfaces will be voltage biased in a preprogrammed step sequence to optimize the data returned for each plasma region and for the available telemetry coverage

Nanoelectronic thermometers optimised for sub-10 millikelvin operation

We report the cooling of electrons in nanoelectronic Coulomb blockade thermometers below 4 mK. Above 7 mK the devices are in good thermal contact with the environment, well isolated from electrical noise, and not susceptible to self-heating. This is attributed to an optimised design that incorporates cooling fins with a high electron-phonon coupling and on-chip electronic filters, combined with a low-noise electronic measurement setup. Below 7 mK the electron temperature is seen to diverge from the ambient temperature. By immersing a Coulomb Blockade Thermometer in the 3He/4He refrigerant of a dilution refrigerator, we measure a lowest electron temperature of 3.7 mK.Comment: 11 pages, 4 figures. (Fixed fitted saturation T_e on p9

Myocardial Infarct Size by CMR in Clinical Cardioprotection Studies Insights From Randomized Controlled Trials

OBJECTIVES: The aim of this study was to review randomized controlled trials (RCTs) using cardiac magnetic resonance (CMR) to assess myocardial infarct (MI) size in reperfused patients with ST-segment elevation myocardial infarction (STEMI). BACKGROUND: There is limited guidance on the use of CMR in clinical cardioprotection RCTs in patients with STEMI treated by primary percutaneous coronary intervention. METHODS: All RCTs in which CMR was used to quantify MI size in patients with STEMI treated with primary percutaneous coronary intervention were identified and reviewed. RESULTS: Sixty-two RCTs (10,570 patients, January 2006 to November 2016) were included. One-third did not report CMR vendor or scanner strength, the contrast agent and dose used, and the MI size quantification technique. Gadopentetate dimeglumine was most commonly used, followed by gadoterate meglumine and gadobutrol at 0.20 mmol/kg each, with late gadolinium enhancement acquired at 10 min; in most RCTs, MI size was quantified manually, followed by the 5 standard deviation threshold; dropout rates were 9% for acute CMR only and 16% for paired acute and follow-up scans. Weighted mean acute and chronic MI sizes (≤12 h, initial TIMI [Thrombolysis in Myocardial Infarction] flow grade 0 to 3) from the control arms were 21 ± 14% and 15 ± 11% of the left ventricle, respectively, and could be used for future sample-size calculations. Pre-selecting patients most likely to benefit from the cardioprotective therapy (≤6 h, initial TIMI flow grade 0 or 1) reduced sample size by one-third. Other suggested recommendations for standardizing CMR in future RCTs included gadobutrol at 0.15 mmol/kg with late gadolinium enhancement at 15 min, manual or 6-SD threshold for MI quantification, performing acute CMR at 3 to 5 days and follow-up CMR at 6 months, and adequate reporting of the acquisition and analysis of CMR. CONCLUSIONS: There is significant heterogeneity in RCT design using CMR in patients with STEMI. The authors provide recommendations for standardizing the assessment of MI size using CMR in future clinical cardioprotection RCTs

Submesoscale hotspots of productivity and respiration : insights from high-resolution oxygen and fluorescence sections

Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 130 (2017): 1-11, doi:10.1016/j.dsr.2017.10.005.Modeling studies have shown that mesoscale and submesoscale processes can stimulate phytoplankton productivity and export production. Here, we present observations from an undulating, towed Video Plankton Recorder (VPR-II) in the tropical Atlantic. The VPR-II collected profiles of oxygen, fluorescence, temperature and salinity in the upper 140 m of the water column at a spatial resolution of 1 m in the vertical and <2 km in the horizontal. The data reveal remarkable "hotspots", i.e. locations 5 to 10 km wide which have elevated fluorescence and decreased oxygen, both of which are likely the result of intense submesoscale upwelling. Based on estimates of source water, estimated from identical temperature and salinity surfaces, hotspots are more often areas of net respiration than areas of net production — although the inferred changes in oxygen are subject to uncertainty in the determination of the source of the upwelled waters since the true source water may not have been sampled. We discuss the spatial distribution of these hotspots and present a conceptual model outlining their possible generation and decline. Simultaneous measurements of O2/Ar in the mixed layer from a shipboard mass spectrometer provide estimates of rates of surface net community production. We find that the subsurface biological hotspots are often expressed as an increase in mixed layer rates of net community production. Overall, the large number of these hotspots support the growing evidence that submesoscale processes are important drivers in upper ocean biological production.Funding for this work came from the National Science Foundation (R.H.R.S. and D.J.M) (OCE-0925284, OCE-1048897, and OCE- 1029676) and the National Aeronautics and Space Administration (D.J.M.) (NNX08AL71G and NNX13AE47G)

Mindfulness meditation targets transdiagnostic symptoms implicated in stress-related disorders: Understanding relationships between changes in mindfulness, sleep quality, and physical symptoms

Mindfulness-Based Stress Reduction (MBSR) is an 8-week meditation program known to improve anxiety, depression, and psychological well-being. Other health-related effects, such as sleep quality, are less well established, as are the psychological processes associated with therapeutic change. This prospective, observational study (n=213) aimed to determine whether perseverative cognition, indicated by rumination and intrusive thoughts, and emotion regulation, measured by avoidance, thought suppression, emotion suppression, and cognitive reappraisal, partly accounted for the hypothesized relationship between changes in mindfulness and two health-related outcomes: sleep quality and stress-related physical symptoms. As expected, increased mindfulness following the MBSR program was directly correlated with decreased sleep disturbance (r=-0.21, p=0.004) and decreased stress-related physical symptoms (r=-0.38, p<0.001). Partial correlations revealed that pre-post changes in rumination, unwanted intrusive thoughts, thought suppression, experiential avoidance, emotion suppression, and cognitive reappraisal each uniquely accounted for up to 32% of the correlation between the change in mindfulness and change in sleep disturbance and up to 30% of the correlation between the change in mindfulness and change in stress-related physical symptoms. Results suggest that the stress-reducing effects of MBSR are due, in part, to improvements in perseverative cognition and emotion regulation, two “transdiagnostic” mental processes that cut across stress-related disorders

Biallelic variants in COX4I1 associated with a novel phenotype resembling Leigh syndrome with developmental regression, intellectual disability, and seizures

Autosomal recessive COX4I1 deficiency has been previously reported in a single individual with a homozygous pathogenic variant in COX4I1, who presented with short stature, poor weight gain, dysmorphic features, and features of Fanconi anemia. COX4I1 encodes subunit 4, isoform 1 of cytochrome c oxidase. Cytochrome c oxidase is a respiratory chain enzyme that plays an important role in mitochondrial electron transport and reduces molecular oxygen to water leading to the formation of ATP. Defective production of cytochrome c oxidase leads to a variable phenotypic spectrum ranging from isolated myopathy to Leigh syndrome. Here, we describe two siblings, born to consanguineous parents, who presented with encephalopathy, developmental regression, hypotonia, pathognomonic brain imaging findings resembling Leigh‐syndrome, and a novel homozygous variant on COX4I1, expanding the known clinical phenotype associated with pathogenic variants in COX4I1

A pseudo-spectral approach to inverse problems in interface dynamics

An improved scheme for computing coupling parameters of the Kardar-Parisi-Zhang equation from a collection of successive interface profiles, is presented. The approach hinges on a spectral representation of this equation. An appropriate discretization based on a Fourier representation, is discussed as a by-product of the above scheme. Our method is first tested on profiles generated by a one-dimensional Kardar-Parisi-Zhang equation where it is shown to reproduce the input parameters very accurately. When applied to microscopic models of growth, it provides the values of the coupling parameters associated with the corresponding continuum equations. This technique favorably compares with previous methods based on real space schemes.Comment: 12 pages, 9 figures, revtex 3.0 with epsf style, to appear in Phys. Rev.

Cotranslational Folding Stimulates Programmed Ribosomal Frameshifting in the Alphavirus Structural Polyprotein

Viruses maximize their genetic coding capacity through a variety of biochemical mechanisms, including programmed ribosomal frameshifting (PRF), which facilitates the production of multiple proteins from a single mRNA transcript. PRF is typically stimulated by structural elements within the mRNA that generate mechanical tension between the transcript and ribosome. However, in this work, we show that the forces generated by the cotranslational folding of the nascent polypeptide chain can also enhance PRF. Using an array of biochemical, cellular, and computational techniques, we first demonstrate that the Sindbis virus structural polyprotein forms two competing topological isomers during its biosynthesis at the ribosome-translocon complex. We then show that the formation of one of these topological isomers is linked to PRF. Coarse-grained molecular dynamics simulations reveal that the translocon-mediated membrane integration of a transmembrane domain upstream from the ribosomal slip site generates a force on the nascent polypeptide chain that scales with observed frameshifting. Together, our results indicate that cotranslational folding of this viral protein generates a tension that stimulates PRF. To our knowledge, this constitutes the first example in which the conformational state of the nascent polypeptide chain has been linked to PRF. These findings raise the possibility that, in addition to RNA-mediated translational recoding, a variety of cotranslational folding or binding events may also stimulate PRF

Prevalence of maternal complications and neonatal outcomes at a Midwest academic health center

Introduction: The University of Iowa Hospitals and Clinics (UIHC) serves as the main referral center for Iowa and has seen increased delivery volumes following many hospital closures across the state. Maternal characteristics are also shifting as pre-pregnancy obesity of reproductive-age women is increasing nationally and in Iowa; average maternal age at first delivery has also increased over time. The aim of the current study was to characterize the outcomes of the delivering population at UIHC over a one-year period to better understand the population we serve, as well as compare our population to state and national delivering populations. Methods: This study is a secondary analysis of a pre-existing prospectively gathered database related to COVID-19 in pregnancy. The current study included all pregnant patients who delivered or underwent procedures for a spontaneous or induced second-trimester abortion on the labor and delivery unit at UIHC between May 1, 2020, and April 30, 2021. Demographic and clinical data including maternal characteristics, delivery information, maternal complications, and neonatal outcomes were obtained from the electronic medical record and double entered in a Research Electronic Data Capture (REDCap) database. Continuous and categorical variables were summarized using medians and ranges. Results: The median maternal age among the 2497 delivering patients was 30 (IQR 26, 33). The median pre-delivery body mass index (BMI) was 32 (IQR 28, 37), which included 439 patients (17.6%) with BMI &gt;40 at time of delivery. 1769 (70.8%) patients listed White as their self-defined race and 2275 (91.0%) listed English as their preferred language. 23% had hypertensive disease of pregnancy. The patients delivered a total of 2603 neonates, with 907 (34.8%) born by cesarean section. 18.7% of deliveries were preterm and 16.6% of neonates had low birth weight. Discussion: The delivering population at UIHC has a high rate of obesity and preeclampsia, both of which place patients at higher risk for other obstetric complications. The cesarean section rate was significantly higher than the national rate of 31.8% (p=0.0017). Understanding common complications in our changing population will better equip providers to care for these patients; providing these data also creates a resource for other researchers

Consumer attitude and intention toward ridesharing

This paper aims to examine the factors affecting consumer’s intention to participate in the sharing economy in particular toward ridesharing services. Data were collected from UberX users in Australia (n = 278) and New Zealand (n = 295) using online survey and analysed through Structural Equation Modelling in AMOS 25. The research model is tested and compared across three studies. The results show that perceived usefulness and word-of-mouth significantly influence the consumers’ attitude toward ridesharing. The results across two samples show that the positive relationship between perceived usefulness as well as word of mouth and attitude toward service innovation is moderated by the consumers’ attitude toward the advertising. In addition, currently the ridesharing application ridesharing requires more effort from the users, especially those who have a lower self-efficacy or are risk adverse towards using this type of service innovation. This paper suggests ridesharing services utilise the power of the word of mouth and peer recommendations in the brand’s promotional strategies. Furthermore, personalised e-guides and instructions can form part of the service user interface which would help curb the negative perception around app usage and complexity, and thus increase consumer confidence