Density-Dependent Response of an Ultracold Plasma to Few-Cycle Radio-Frequency Pulses

Ultracold neutral plasmas exhibit a density-dependent resonant response to applied radio-frequency (RF) fields in the frequency range of several MHz to hundreds of MHz for achievable densities. We have conducted measurements where short bursts of RF were applied to these plasmas, with pulse durations as short as two cycles. We still observed a density-dependent resonant response to these short pulses. However, the too rapid timescale of the response, the dependence of the response on the sign of the driving field, the response as the number of pulses was increased, and the difference in plasma response to radial and axially applied RF fields are inconsistent with the plasma response being due to local resonant heating of electrons in the plasma. Instead, our results are consistent with rapid energy transfer from collective motion of the entire electron cloud to electrons in high-energy orbits. In addition to providing a potentially more robust way to measure ultracold neutral plasma densities, these measurements demonstrate the importance of collective motion in the energy transport in these systems.Comment: 5 pages, 4 figure

Subsample Difference Correction for Terra MODIS SWIR Bands 5-7 Using Lunar Observations

The Moderate Resolution Imaging Spectroradiometer (MODIS) is one of the key instruments on board the Terra (EOS (Earth Observing Satellite) AM-1) spacecraft. MODIS has 36 spectral bands ranging in wavelength between 0.4 and 14.2 microns, at three spatial resolutions of 250 meters (bands 1-2), 500 meters (bands 3-7), and 1 kilometer (bands 8-36). For each 1-km sample, the 250-m and 500-m bands use 4 and 2 detectors with each acquiring 4 and 2 subsamples respectively in order to maintain consistent along-scan and along-track resolutions at nadir. The SWIR (Short-Wave Infrared) bands, 57 and 26, share the same focal-plane array as the 1-km thermal emissive bands, 20-25. During one of the two 500-m subsamples for bands 57, sampling of the 1-km bands introduces increased electronic crosstalk contamination, resulting in a subsample difference for both Earth-view and on-board calibrator observations. For this work, we use data from lunar and on-board blackbody observations, which occur at different signal levels for bands 20-25, to derive a correction to the contamination. This correction can be applied to reduce the subsample differences in the MODIS Earth-view data over a wide range of scenes. The impact of this correction on the sensor calibration and Earth-view data will be assessed

Sensor Performance Assessment for Terra and Aqua MODIS Using Unscheduled Lunar Observations

The Moderate Resolution Imaging Spectroradiometer (MODIS) has been in operation for over 18 and 16 years on the Terra and Aqua spacecrafts, respectively. In order to maintain long-term calibration stability over the life of each mission, MODIS uses a set of on-board calibrators as well as observations of the Moon and selected Earth-view targets. The lunar observations nominally occur in a narrow phase angle range, 55 degrees - 56 degrees, and use scheduled spacecraft maneuvers in order to bring the Moon into alignment with the MODIS space-view port. These observations are used to help characterize the MODIS scan-mirror response versus scan-angle. In addition to these scheduled lunar observations, MODIS also views the Moon through the space-view port without a spacecraft maneuver when the geometry is appropriately aligned. This occurs over a wider phase angle range, between 51 degrees - 82 degrees, than those of the scheduled moon observations. While the phase angle restriction of our scheduled observations provides consistency between the calibration events, the unscheduled Moon data can provide a valuable assessment of many calibration related investigations that use the Moon. In this paper, we compare the results of unscheduled versus scheduled lunar observations for several sensor calibration and performance assessments. These include the lunar calibration trending used to characterize the scan-mirror response versus scan angle and the electronic crosstalk correction of bands 27-30, which are currently used in the MODIS Level-1B data products, as well as sensor performance assessments such as band-to-band and detector-to-detector spatial registration

Factors Influencing Sleep Difficulty and Sleep Quantity in the Citizen Pscientist Psoriatic Cohort.

IntroductionSleep is essential for overall health and well-being, yet more than one-third of adults report inadequate sleep. The prevalence is higher among people with psoriasis, with up to 85.4% of the psoriatic population reporting sleep disruption. Poor sleep among psoriasis patients is particularly concerning because psoriasis is independently associated with many of the same comorbidities as sleep dysfunction, including cardiovascular disease, obesity, and depression. Given the high prevalence and serious consequences of disordered sleep in psoriasis, it is vital to understand the nature of sleep disturbance in this population. This study was designed to help meet this need by using survey data from Citizen Pscientist, an online patient portal developed by the National Psoriasis Foundation.MethodsOur analysis included 3118 participants who identified as having a diagnosis by a physician of psoriasis alone or psoriasis with psoriatic arthritis. Demographic information, psoriasis severity and duration, sleep apnea status, smoking and alcohol consumption, itch timing, and sleep characteristics were included. Two separate multivariate logistic regression models in STATA were used to determine whether the presence of psoriatic arthritis, age, gender, body mass index, comorbid sleep apnea, psoriasis severity, timing of worst itch, smoking status, or high-risk alcohol consumption were associated with sleep difficulty or low sleep quantity, defined by the American Academy of Sleep Medicine as less than 7 h of sleep per night on average.ResultsResults from the multivariate logistic regressions found that sleep difficulty was associated with psoriatic arthritis (OR 2.15, 95% CI [1.79-2.58]), female gender (2.03 [1.67-2.46]), obese body mass index (BMI ≥ 30) (1.25 [1.00-1.56]), sleep apnea (1.41 [1.07-1.86]), psoriasis severity of moderate (1.59 [1.30-1.94]) or severe (2.40 [1.87-3.08]), and smoking (1.60 [1.26-2.02]). Low sleep quantity was associated with obese BMI (1.62 [1.29-2.03]), sleep apnea (1.30 [1.01-1.68]), psoriasis severity of moderate (1.41 [1.16-1.72]) or severe (1.40 [1.11-1.76]), and smoking (1.62 [1.31-2.00]). Sleep difficulty and low sleep quantity were not associated with age, alcohol consumption, or timing of worst itch.ConclusionThese results are potentially meaningful in several aspects. We identify an important distinction between sleep difficulty and sleep quantity in psoriatic disease, whereby having psoriatic arthritis and being female are each associated with sleep difficulty despite no association with low sleep quantity. Furthermore, there is conflicting evidence from prior studies as to whether psoriasis severity is associated with sleep difficulty, but this well-powered, large study revealed a strong, graded relationship between psoriasis severity and both sleep difficulty and low sleep quantity. Overall, our results show that both sleep difficulty and low sleep quantity were associated with multiple factors in this analysis of a large psoriatic cohort. These findings suggest that dermatologists may gather clinically useful information by screening psoriatic patients for trouble sleeping and low sleep quantity to identify potential comorbidities and to more effectively guide disease management

Considerations for legal, ethical, and effective practice in dementia research

Dementia represents a potentially overwhelming health burden, both for the UK and worldwide. Addressing this fast-growing issue is a key priority for the government, health service and the public. Advances in care including the development of efficacious disease-modifying, and eventually curative, treatments can only be achieved through effective dementia research. Specifically, research directly involving participants with dementia is essential to further understanding. However, working with cognitively impaired participants with and without capacity to consent to research presents unique ethical and legal challenges. For clinicians and scientists on the frontline of dementia research, scenarios frequently arise that pose such challenges. A lack of guidance for a consistent approach in navigating these scenarios limits researchers’ ability to proceed with confidence. This represents a threat to the rights and wishes of research participants as well as the field at large, as it may lead to studies being unnecessarily terminated or, worse, poor practice. In this article, we take a multiprofessional approach, informed by carer input, to these issues. We review the relevant ethical and legal literature relating to the conduct of non-interventional research studies in patients with dementia. This includes a thorough recap of the Mental Capacity Act (2005), which provides a legal framework in England and Wales for conducting research with participants who lack capacity to consent. We also discuss the important, but sometimes incomplete, role of research ethics committees in guiding researchers. We then present and discuss a series of case vignettes designed to highlight areas of incomplete coverage by existing governance. These vignettes describe theoretical scenarios informed by our own real-word experiences of encountering ethical issues when conducting dementia research. They include scenarios in which participants demonstrate varying degrees of understanding of the research they are involved in and ability to communicate their wishes and feelings. Building on these vignettes, we then provide a checklist for researchers to work through when presented with similar scenarios. This checklist covers the key ethical, legal and practical considerations that we have argued for. Taken together, this article can act as a guide, previously lacking in the literature, for colleagues in the field to enable much needed ethical, legal and effective research

ReseArch with Patient and Public invOlvement: a RealisT evaluation - the RAPPORT study

Background Patient and public involvement (PPI) is a prerequisite for many funding bodies and NHS research ethics approval. PPI in research is defined as research carried out with or by the public rather than to, about or for them. While the benefits of PPI have been widely discussed, there is a lack of evidence on the impact and outcomes of PPI in research. Objectives To determine the types of PPI in funded research, describe key processes, analyse the contextual and temporal dynamics of PPI and explore the experience of PPI in research for all those involved. Mechanisms contributing to the routine incorporation of PPI in the research process were assessed, the impact of PPI on research processes and outcomes evaluated, and barriers and enablers to effective PPI identified. Design A three-staged realist evaluation drawing on Normalisation Process Theory to understand how far PPI was embedded within health-care research in six areas: diabetes mellitus, arthritis, cystic fibrosis, dementia, public health and learning disabilities. The first two stages comprised a scoping exercise and online survey to chief investigators to assess current PPI activity. The third stage consisted of case studies tracked over 18 months through interviews and document analysis. The research was conducted in four regions of England. Participants Non-commercial studies currently running or completed within the previous 2 years eligible for adoption on the UK Clinical Research Network portfolio. A total of 129 case study participants included researchers and PPI representatives from 22 research studies, and representatives from funding bodies and PPI networks

Common and Distinct Roles of Juvenile Hormone Signaling Genes in Metamorphosis of Holometabolous and Hemimetabolous Insects

Insect larvae metamorphose to winged and reproductive adults either directly (hemimetaboly) or through an intermediary pupal stage (holometaboly). In either case juvenile hormone (JH) prevents metamorphosis until a larva has attained an appropriate phase of development. In holometabolous insects, JH acts through its putative receptor Methoprene-tolerant (Met) to regulate Krüppel-homolog 1 (Kr-h1) and Broad-Complex (BR-C) genes. While Met and Kr-h1 prevent precocious metamorphosis in pre-final larval instars, BR-C specifies the pupal stage. How JH signaling operates in hemimetabolous insects is poorly understood. Here, we compare the function of Met, Kr-h1 and BR-C genes in the two types of insects. Using systemic RNAi in the hemimetabolous true bug, Pyrrhocoris apterus, we show that Met conveys the JH signal to prevent premature metamorphosis by maintaining high expression of Kr-h1. Knockdown of either Met or Kr-h1 (but not of BR-C) in penultimate-instar Pyrrhocoris larvae causes precocious development of adult color pattern, wings and genitalia. A natural fall of Kr-h1 expression in the last larval instar normally permits adult development, and treatment with an exogenous JH mimic methoprene at this time requires both Met and Kr-h1 to block the adult program and induce an extra larval instar. Met and Kr-h1 therefore serve as JH-dependent repressors of deleterious precocious metamorphic changes in both hemimetabolous and holometabolous juveniles, whereas BR-C has been recruited for a new role in specifying the holometabolous pupa. These results show that despite considerable evolutionary distance, insects with diverse developmental strategies employ a common-core JH signaling pathway to commit to adult morphogenesis

The Costs and Benefits of American Policymaking Venues

Many law and policy scholars consider judges inimical to good public policymaking, and the criticisms they level on the judiciary implicitly reflect some of the concerns raised by Alexander Bickel and other critics. Despite the charge by critics that judges are institutionally ill equipped to participate in the policy-making process and that legal processes are costly, there are reasons to believe otherwise. This article uses field interviews and three case studies of an environmental dispute in the Pacific Northwest to show that the judiciary can be an institutional venue that enhances public input, can be more inclusive than other venues, and produces positive-sum outcomes when other venues cannot. The findings also suggest that legislative and agency policymaking are just as contentious and costly as judicial policy-making processes