We present the lessons learned about the degradation observed in several space solar missions, based on contributions at the Workshop about On-Orbit Degradation of Solar and Space Weather Instruments ...that took place at the Solar Terrestrial Centre of Excellence (Royal Observatory of Belgium) in Brussels on 3 May 2012. The aim of this workshop was to open discussions related to the degradation observed in Sun-observing instruments exposed to the effects of the space environment. This article summarizes the various lessons learned and offers recommendations to reduce or correct expected degradation with the goal of increasing the useful lifespan of future and ongoing space missions.
The metal hyperaccumulator plant Noccaea caerulescens is protected from disease by the accumulation of high concentrations of metals in its aerial tissues, which are toxic to many pathogens. As these ...metals can lead to the production of damaging reactive oxygen species (ROS), metal hyperaccumulator plants have developed highly effective ROS tolerance mechanisms, which might quench ROS-based signals. We therefore investigated whether metal accumulation alters defence signalling via ROS in this plant.
We studied the effect of zinc (Zn) accumulation by N. caerulescens on pathogen-induced ROS production, salicylic acid accumulation and downstream defence responses, such as callose deposition and pathogenesis-related (PR) gene expression, to the bacterial pathogen Pseudomonas syringae pv. maculicola.
The accumulation of Zn caused increased superoxide production in N. caerulescens, but inoculation with P. syringae did not elicit the defensive oxidative burst typical of most plants. Defences dependent on signalling through ROS (callose and PR gene expression) were also modified or absent in N. caerulescens, whereas salicylic acid production in response to infection was retained.
These observations suggest that metal hyperaccumulation is incompatible with defence signalling through ROS and that, as metal hyperaccumulation became effective as a form of elemental defence, normal defence responses became progressively uncoupled from ROS signalling in N. caerulescens.
Summary
Background
Exposure to low levels of vitamin D in fetal life might be a risk factor for childhood asthma.
Objective
We examined whether 25‐hydroxyvitamin D levels in mid‐gestation and at ...birth were associated with higher airway resistance and inflammation, and increased risks of wheezing and asthma in school‐age children.
Methods
We performed a population‐based prospective cohort study among 3130 mothers and their children. Maternal blood samples in mid‐gestation and umbilical cord blood samples at birth were used to determine 25‐hydroxyvitamin D levels. At age of 6, airway resistance (Rint) was measured by interrupter technique and airway inflammation by fractional exhaled nitric oxide (FENO) using NIOX chemiluminescence analyser. Wheezing and asthma were prospectively assessed by annual questionnaires until age 6.
Results
Maternal levels of 25‐hydroxyvitamin D in mid‐gestation were not associated with Rint, FeNO, wheezing patterns, or asthma. Children in the lowest tertile of 25‐hydroxyvitamin D levels at birth had a higher Rint (Z‐score (95% confidence interval 95% CI): −0.42 (−0.84, −0.01), P‐value for trend< 0.05), compared to those in the highest tertile group. The effect estimate attenuated when child's current 25‐hydroxyvitamin D level was taken into account Z‐score (95% CI): −0.55 (−1.08, 0.01).
Conclusion and Clinical Relevance
Low levels of 25‐hydroxyvitamin D at birth were associated with a higher airway resistance in childhood. Additional adjustment for child's current 25‐hydroxyvitamin D level reduced the effect size of the association. Further studies are needed to replicate these findings and to examine mechanisms underlying the observed association and the long‐term consequences.
The suite of SECCHI optical imaging instruments on the STEREO‐A spacecraft is used to track a solar storm, consisting of several coronal mass ejections (CMEs) and other coronal loops, as it ...propagates from the Sun into the heliosphere during May 2007. The 3‐D propagation path of the largest interplanetary CME (ICME) is determined from the observations made by the SECCHI Heliospheric Imager (HI) on STEREO‐A (HI‐1/2A). Two parts of the CME are tracked through the SECCHI images, a bright loop and a V‐shaped feature located at the rear of the event. We show that these two structures could be the result of line‐of‐sight integration of the light scattered by electrons located on a single flux rope. In addition to being imaged by HI, the CME is observed simultaneously by the plasma and magnetic field experiments on the Venus Express and MESSENGER spacecraft. The imaged loop and V‐shaped structure bound, as expected, the flux rope observed in situ. The SECCHI images reveal that the leading loop‐like structure propagated faster than the V‐shaped structure, and a decrease in in situ CME speed occurred during the passage of the flux rope. We interpret this as the result of the continuous radial expansion of the flux rope as it progressed outward through the interplanetary medium. An expansion speed in the radial direction of ∼30 km s−1 is obtained directly from the SECCHI‐HI images and is in agreement with the difference in speed of the two structures observed in situ. This paper shows that the flux rope location can be determined from white light images, which could have important space weather applications.
Rotationally inelastic collisions of NO(X) with Ar are investigated in unprecedented detail using state-to-state, crossed molecular beam experiments. The NO(X) molecules are selected in the
= 0.5,
= ...0.5,
state and then oriented such that either the 'N' or 'O' end of the molecule is directed towards the incoming Ar atom. Velocity map ion imaging is then used to probe the scattered NO molecules in well-defined quantum states. We show that the fully quantum state-resolved differential steric asymmetry, which quantifies how the relative efficiency for scattering off the 'O' and the 'N' ends of the molecule varies with scattering angle, is strongly affected by quantum interference. Significant changes in both integral and differential cross sections are found depending on whether collisions occur with the N or O ends of the molecule. The results are well accounted for by rigorous quantum mechanical calculations, in contrast to both classical trajectory calculations and more simplistic models that provide, at best, an incomplete picture of the dynamics.
The
Heliospheric Imagers
(HI) on the
Solar TErrestrial RElations Observatory
(STEREO) observe the solar wind and disturbances therein as it propagates from close to the Sun to 1 AU and beyond. In ...this article we use stellar photometry over much of the mission to date to make a determination of the long-term evolution of the photometric response of the inner (HI-1) cameras. We find very slow degradation rates of the order of 0.1 % per year, similar to those found for HI-2 by Tappin, Eyles and Davies (
Solar Phys.
290
, 2143,
2015
) and significantly slower than rates found for other comparable instruments. We also find that it is necessary to make a small (
≈
1
%
) revision to the photometric calibration parameters used to convert instrument units into physical units. Finally, we briefly discuss the effects of pointing instabilities on the measurement of stellar count rates.
We present a concept for a small mission to the Sun–Earth Lagrangian L5 point for innovative solar, heliospheric and space weather science. The proposed INvestigation of Solar-Terrestrial Activity ...aNd Transients (INSTANT) mission is designed to identify how solar coronal magnetic fields drive eruptions, mass transport and particle acceleration that impact the Earth and the heliosphere. INSTANT is the first mission designed to (1) obtain measurements of coronal magnetic fields from space and (2) determine coronal mass ejection (CME) kinematics with unparalleled accuracy. Thanks to innovative instrumentation at a vantage point that provides the most suitable perspective view of the Sun–Earth system, INSTANT would uniquely track the whole chain of fundamental processes driving space weather at Earth. We present the science requirements, payload and mission profile that fulfill ambitious science objectives within small mission programmatic boundary conditions.
•A small mission concept to the Sun–Earth Lagrangian L5 point is proposed.•The mission tackles new science objectives with innovative instrumentation.•A full mission design consistent with small mission constraints is described.
In 2007 January, at the heliocentric distance r < 0.3 AU, comet McNaught 2006P1 became the brightest comet since C/Ikeya-Seki 1965S1 and was continuously monitored by space-based solar observatories. ...We provide strong evidence that an archlike tail observed by the Heliospheric Imager aboard the STEREO spacecraft is the first ever detected tail composed of neutral Fe atoms. We obtain an Fe lifetime tau = (4.1 plus or minus 0.4) x 10 super(1) s at r = 0.25 AU, in agreement with theoretical predictions of the photoionization lifetime. The expected dust temperature is inconsistent with iron sublimation, suggesting that Fe atoms are coming from troilite evaporation.
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