Comparing the Atmospheres of Mercury and the Earth's Moon

The exospheres of Mercury and the Earth's Moon are fundamentally similar, but the differences that do exist between them can help us to develop a better understanding of the processes at work on the two bodies that produce and remove volatiles. The major differences are derived from (1) the different compositions of the two surfaces, (2) the different particle and field em'ironments above the surface of each body (particularly the presence of intrinsic magnetic field of Mercury), and (3) the larger flux of interplanetary dust incident at the orbit of Mercury. The first difference, surface composition, is the most intractable problem, but the most challenging part of that problem, the composition of the Hermean regolith, may be at least partially addressed as the MESSENGER mission completes work over the next year. Much progress has been made with respect to exploring the second difference above--spacecraft such as Helios, Ulysses, WIND, and ACE have measured the solar wind and its composition both in Earth orbit and at distances encompassing the orbit of Mercury. While our knowledge of the solar wind is incomplete, again it is far more detailed than a simple 1/R(sup 2) law would predict. Another problem is that of the flux of charged particles to the surfaces. While Mercury's magnetosphere is the subject of current study with MESSENGER, the influx of charged particles on the Moon has gone beyond a cos (psi) picture, where psi is the solar zenith angle. We know that the influx of ions at the Moon is affected by magnetic anomalies, by craters, and by surface charging. The third external difference is the differing flux of interplanetary dust incident on the two surfaces. In this talk we will consider: (1) the species that one can compare now for these two exospheres (Na, K, and He); (2) the species that you might be able to compare with future measurements (Ca and Mg); arid (3) how intensive ground-based observations of the easiest lunar species to observe from the ground, Na and K, might help us address source processes at work on both surfaces. We will discuss current and planned modeling efforts for both the lunar and Hermean exospheres, and some current and planned observations, both ground-based and space-based

A Small, Remotely Operated, Coronagraph located at Small Observatory to obtain Frequent Low-cost Remote Observations of the Lunar Exosphere

The sodium in the lunar exosphere is a marker for the study of the lunar exosphere because the sodium possesses two strong resonance transitions from the ground state whose wavelengths fall in the visible spectrum near 590 nm. Emissions at these wavelengths are thus, observable from Earth. Observations have shown that the exosphere responds in a complex way to the external processes (impact vaporization, sputtering, and photon stimulated desorption) that weather the lunar regolith to produce the sodium (Sarantos et aI., Icarus, 205, 2010). Unraveling the sodium production allows us to study the processes that weather the regolith. Obtaining the extensive time sequence of observations required to unravel the sources of sodium using conventional observatories is impractical, and too expensive. Effectively imaging the lunar sodium exosphere close to the Moon requires an off-axis rejection of scattered light that can only be obtained with a coronagraph sited at an observatory dedicated to remote robotic observing (the Winer Observatory in Sonoita Arizona) that can obtain the quality and quantity of lunar sodium observations needed to answer these questions, and at modest cost. The design uses Commercial Off the Shelf Technology (COTS). We are working to begin routine the observations before the launch of the Lunar Atmosphere and Dust Environment Explorer (LADEE) mission

Coronagraphic Observations of the Lunar Sodium Exosphere January-June, 2017

In order to observe the lunar sodium exosphere out to one-half degree around the Moon, we designed, built and installed a small robotically controlled coronagraph at the Winer Observatory in Sonoita, Arizona. Observations are obtained remotely every available clear night from our home base at Goddard Space Flight Center or from Prescott, Arizona. We employ an Andover temperature-controlled 1.5-angstrom-wide narrow-band filter centered on the sodium D2 line, and a similar 1.5-angstrom filter centered blueward of the D2 line by 3 angstroms for continuum observations. Our data encompass lunations in 2015, 2016, and 2017, thus we have a long baseline of sodium exospheric calibrated images. During the course of three years we have refined the observational sequence in many respects. Therefore this paper only presents the results of the spring, 2017, observing season. We present limb profiles from the south pole to the north pole for many lunar phases. Our data do not fit any power of cosine model as a function of lunar phase or with latitude. The extended Na exosphere has a characteristic temperature of about 22506750 degrees Kelvin, indicative of a partially escaping exosphere. The hot escaping component may be indicative of a mixture of impact vaporization and a sputtered component

Covid-19 is an opportunity for gender equality within the workplace and at home

Could covid-19 help unravel gender norms

Key Considerations for Accountability and Gender in Health Systems in Low- and Middle-Income Countries

This article poses questions, challenges, and dilemmas for health system researchers striving to better understand how gender shapes accountability mechanisms, by critically examining the relationship between accountability and gender in health systems. It raises three key considerations, namely that: (1) power and inequities are centre stage: power relations are critical to both gender and accountability, and accountability mechanisms can transform health systems to be more gender-equitable; (2) intersectionality analyses are necessary: gender is only one dimension of marginalisation and intersects with other social stratifiers to create different experiences of vulnerability; we need to take account of how these stratifiers collectively shape accountability; and (3) empowerment processes that address gender inequities are a prerequisite for bringing about accountability. We suggest that holistic approaches to understanding health systems inequities and accountability mechanisms are needed to transform gendered power inequities, impact on the gendered dimensions of ill health, and enhance health system functioning.Open Society Foundations, Vozes Desiguais/Unequal Voices, Future Health Systems consortium, the Impact Initiative and Health Systems Globa

Performance of private sector health care: implications for universal health coverage

Although the private sector is an important health-care provider in many low-income and middle-income countries, its role in progress towards universal health coverage varies. Studies of the performance of the private sector have focused on three main dimensions: quality, equity of access, and efficiency. The characteristics of patients, the structures of both the public and private sectors, and the regulation of the sector influence the types of health services delivered, and outcomes. Combined with characteristics of private providers-including their size, objectives, and technical competence-the interaction of these factors affects how the sector performs in different contexts. Changing the performance of the private sector will require interventions that target the sector as a whole, rather than individual providers alone. In particular, the performance of the private sector seems to be intrinsically linked to the structure and performance of the public sector, which suggests that deriving population benefit from the private health-care sector requires a regulatory response focused on the health-care sector as a whole

Mapping local structural perturbations in the native state of stefin B (cystatin B) under amyloid forming conditions

Unlike a number of amyloid-forming proteins, stefins, and in particular stefin B (cystatin B) form amyloids under conditions where the native state predominates. In order to trigger oligomerization processes, the stability of the protein needs to be compromised, favoring structural re-arrangement however, accelerating fibril formation is not a simple function of protein stability. We report here on how optimal conditions for amyloid formation lead to the destabilization of dimeric and tetrameric states of the protein in favor of the monomer. Small, highly localized structural changes can be mapped out that allow us to visualize directly areas of the protein which eventually become responsible for triggering amyloid formation. These regions of the protein overlap with the Cu (II)-binding sites which we identify here for the first time. We hypothesize that in vivo modulators of amyloid formation may act similarly to painstakingly optimized solvent conditions developed in vitro. We discuss these data in the light of current structural models of stefin B amyloid fibrils based on H-exchange data, where the detachment of the helical part and the extension of loops were observed

Snap shots from a photo competition: what does it reveal about close-to-community providers, gender and power in health systems?

In this commentary, we discuss a photography competition, launched during the summer of 2014, to explore the everyday stories of how gender plays out within health systems around the world. While no submission fees were charged nor financial awards involved, the winning entries were exhibited at the Global Symposium on Health Systems Research in Cape Town, South Africa, in October 2014, with credits to the photographers involved. Anyone who had an experience of, or interest in, gender and health systems was invited to participate. Underlying the aims of the photo competition was a recognition of the importance of participation of community members, health workers and other non-academics in our research engagement and in venues where their perspectives are often missing. The competition elicited participation from a range of stakeholders engaged in health systems: professional photographers, project managers, donors, researchers, activists and community members. In total, 54 photos were submitted by 29 participants from 15 different nationalities and country locations. We unpack what the photos suggest about gender and health systems and the pivotal role of community-level systems that support health, including that of close-to-community health providers. Three themes emerged: women active on the frontlines of service delivery and as primary unpaid carers, the visibility of men in gender and health systems and the inter-sectoral nature and intra-household dynamics of community health that embed close-to-community health providers. The question of who has the right to take and display images, under what contexts and for what purpose also permeated the photo competition. We reflect on how photos can be valuable representations of the worlds that we, health workers and health systems are embedded in. Photographs broaden our horizons by capturing and connecting us to subjects from afar in seemingly unmediated ways but also reflect the politics, values and subjectivities of the photographer. They represent stereotypes, but also showcase alternate realities of people and health systems, and thereby can engender further reflection and change. We conclude with thoughts about the place of photography in health systems research and practice in highlighting and potentially transforming how we look at and address close-to-community providers.</p