Spectral, Compositional, and Physical Properties of the Upper Murray Formation and Vera Rubin Ridge, Gale Crater, Mars.

During 2018 and 2019, the Mars Science Laboratory Curiosity rover investigated the chemistry, morphology, and stratigraphy of Vera Rubin ridge (VRR). Using orbital data from the Compact Reconnaissance Imaging Spectrometer for Mars, scientists attributed the strong 860 nm signal associated with VRR to the presence of red crystalline hematite. However, Mastcam multispectral data and CheMin X-ray diffraction (XRD) measurements show that the depth of the 860 nm absorption is negatively correlated with the abundance of red crystalline hematite, suggesting that other mineralogical or physical parameters are also controlling the 860 nm absorption. Here, we examine Mastcam and ChemCam passive reflectance spectra from VRR and other locations to link the depth, position, and presence or absence of iron-related mineralogic absorption features to the XRD-derived rock mineralogy. Correlating CheMin mineralogy to spectral parameters showed that the ~860 nm absorption has a strong positive correlation with the abundance of ferric phyllosilicates. New laboratory reflectance measurements of powdered mineral mixtures can reproduce trends found in Gale crater. We hypothesize that variations in the 860 nm absorption feature in Mastcam and ChemCam observations of VRR materials are a result of three factors: (1) variations in ferric phyllosilicate abundance due to its ~800-1,000 nm absorption; (2) variations in clinopyroxene abundance because of its band maximum at ~860 nm; and (3) the presence of red crystalline hematite because of its absorption centered at 860 nm. We also show that relatively small changes in Ca-sulfate abundance is one potential cause of the erosional resistance and geomorphic expression of VRR.

Synergistic Ground and Orbital Observations of Iron Oxides on Mt. Sharp and Vera Rubin Ridge.

Visible/short-wave infrared spectral data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) show absorptions attributed to hematite at Vera Rubin ridge (VRR), a topographic feature on northwest Mt. Sharp. The goals of this study are to determine why absorptions caused by ferric iron are strongly visible from orbit at VRR and to improve interpretation of CRISM data throughout lower Mt. Sharp. These goals are achieved by analyzing coordinated CRISM and in situ spectral data along the Curiosity Mars rover's traverse. VRR bedrock within areas that have the deepest ferric absorptions in CRISM data also has the deepest ferric absorptions measured in situ. This suggests strong ferric absorptions are visible from orbit at VRR because of the unique spectral properties of VRR bedrock. Dust and mixing with basaltic sand additionally inhibit the ability to measure ferric absorptions in bedrock stratigraphically below VRR from orbit. There are two implications of these findings: (1) Ferric absorptions in CRISM data initially dismissed as noise could be real, and ferric phases are more widespread in lower Mt. Sharp than previously reported. (2) Patches with the deepest ferric absorptions in CRISM data are, like VRR, reflective of deeper absorptions in the bedrock. One model to explain this spectral variability is late-stage diagenetic fluids that changed the grain size of ferric phases, deepening absorptions. Curiosity's experience highlights the strengths of using CRISM data for spectral absorptions and associated mineral detections and the caveats in using these data for geologic interpretations and strategic path planning tools.

Evidence for a Diagenetic Origin of Vera Rubin Ridge, Gale Crater, Mars: Summary and Synthesis of Curiosity's Exploration Campaign.

This paper provides an overview of the Curiosity rover's exploration at Vera Rubin ridge (VRR) and summarizes the science results. VRR is a distinct geomorphic feature on lower Aeolis Mons (informally known as Mount Sharp) that was identified in orbital data based on its distinct texture, topographic expression, and association with a hematite spectral signature. Curiosity conducted extensive remote sensing observations, acquired data on dozens of contact science targets, and drilled three outcrop samples from the ridge, as well as one outcrop sample immediately below the ridge. Our observations indicate that strata composing VRR were deposited in a predominantly lacustrine setting and are part of the Murray formation. The rocks within the ridge are chemically in family with underlying Murray formation strata. Red hematite is dispersed throughout much of the VRR bedrock, and this is the source of the orbital spectral detection. Gray hematite is also present in isolated, gray-colored patches concentrated toward the upper elevations of VRR, and these gray patches also contain small, dark Fe-rich nodules. We propose that VRR formed when diagenetic event(s) preferentially hardened rocks, which were subsequently eroded into a ridge by wind. Diagenesis also led to enhanced crystallization and/or cementation that deepened the ferric-related spectral absorptions on the ridge, which helped make them readily distinguishable from orbit. Results add to existing evidence of protracted aqueous environments at Gale crater and give new insight into how diagenesis shaped Mars' rock record.

Publishing a nursing textbook: collaborating through "seamless technology".

Electronic communication can enhance long-distance networking and scholarly activity and make long-distance collaboration through technology a reality. Technology presents a new world of opportunity for improving writing skills, nurturing collegiality, and maximizing efficiency in the successful completion of collaborative projects. The concept of "seamless technology" introduced by the authors provides a guide to assist partners involved in collaborative projects to manage technology for a successful, rewarding experience. Basic questions regarding technology that need to be answered on the front end of a long-distance project are suggested in this article. In addition, the steps taken by the authors to co-author and co-edit a nursing textbook and accompanying instructor's manual by using electronic communication and other sources of technology are outlined. The authors address ways that long-distance collaboration required them to maximize their communication and planning skills, thereby increasing productivity and reducing costs. The challenges and rewards of working together exclusively through technology are discussed, and finally, implications for professional nursing are addressed.

Competency outcomes for learning and performance assessment. Redesigning a BSN curriculum.

In an atmosphere in which disgruntled students appeal to their legislators for intervention and faculty give few unsatisfactory clinical grades, the faculty of this state supported school of nursing began a two-step process to strengthen the assessment of students. The first step consisted of the appointment of a testing committee to provide faculty with ongoing assistance with test construction. The next concerned clinical evaluation.

The grief experience of older women whose husbands had hospice care.

Grief is a universal phenomenon, affecting every age and culture. However, the literature reveals that this concept is surrounded with ambiguity and conflicting research findings. There are few studies which focus on the grief of older widows, and none which focuses on the grief of older women whose husbands received hospice care. The purpose of this longitudinal study was to generate a conceptual definition and theory of grief for older adult women using grounded theory methodology. Informants comprised six older widows whose husbands were enrolled in a hospice programme in a southern metropolitan setting in the United States. Each informant was asked to respond to the initial question: "What is your experience in dealing with the loss of your husband?' Interviews were conducted in the widows' homes after the deaths of their husbands during the following three time frames of bereavement: 1-4 months, 7-10 months and 13-16 months. Interviews were audio-taped, transcribed, coded and analysed using the constant comparative method. Oracle, a text-oriented database management computer program, was used to facilitate the creation, storage, coding, analysis and retrieval of data. Cross-comparisons of the findings from the three phases of data collection were made and these findings were compared with the literature. The following core concepts emerged from the data: "being aware', "experiencing distress', "supporting', "coping' and "facing new realities'. Core concepts were combined into a conceptual definition of grief and a grounded theory of grief of older adult women whose husbands experienced hospice care was developed. The results of this study expand our knowledge of the grief process of older widows whose husbands received hospice care and have implications for the development of effective bereavement intervention programmes.

Mothers grieving the death of a child. Case reports of maternal grief.

Research has shown that the experience of losing a child is by far the most painful. It is documented that bereaved parents have more intense symptomatology than adults grieving other types of loss, such as the loss of a spouse or parent. However, there are fewer studies that focus on parental grief than on other types of grief. This article presents case reports of two mothers grieving the deaths of their children. This presentation is unique because grief as a process is explicated from the perspective of the mothers by means of qualitative and quantitative analysis. Taped semistructured interview sessions were conducted monthly and analyzed using grounded theory. These results were compared to results obtained from the analysis of two quantitative symptom inventories--the SCL-90-R, a psychological distress scale, and the GEI, a 135 item grief experience inventory. The experience of maternal grief that is presented through case examples will enable practitioners to connect theory with practical application to ease the suffering of grieving parents.

An analysis of the concept of grief.

Grief is a universal response affecting every age and culture. However, this concept is surrounded by ambiguity. It is poorly understood by nurses who encounter grieving persons with increasing frequency, especially as the population ages. The ability of nurses to gain an increased understanding of grief depends on the clarification of this concept. A concept analysis is described. Antecedents, attributes, referents and intervening variables of grief are identified. In addition, model, borderline, related, invented and contrary cases are described. This analysis results in a comprehensive definition of grief which is proposed. This definition can contribute to the foundation essential to guide nursing practice with grieving persons.

Preholiday grief. Facing it alone.

These strategies for coping with the holidays following a loss can be shared not only in a group format such as a preholiday workshop, but also on a one-to-one basis by caring health professionals. To be effective in promoting adaptation to loss, it is vital that health-care professionals heighten their awareness of the needs and reactions of the grieving person. Their sensitivity to the anxiety and pain that can accompany the holiday season must increase. Only when awareness and sensitivity increase will there be an increase in the development of effective bereavement outreach programs. Through such programs the bereaved can experience positive encounters with caring professionals who can help them establish a new sense of hope, purpose, and renewed self-esteem.

In vitro glucan synthesis by membranes of celery petioles: the role of the membrane in determining the type of linkage formed.

Glucan synthesis was achieved with an in vitro membrane fraction from the petioles of celery (Apium graveolens). The optimum conditions for maximum synthesis were established. The Km and Vmax for the enzymic system were 1.0 mM and 0.19 microM min-1 mg protein-1, respectively. Mechanical damage to the membrane fraction altered the proportion of beta-(1----3) to beta-(1----4) glucosyl linkages that were synthesized. We suggest that cellulose synthesis (beta-(1----4)-linked glucan chains) is controlled by the availability of UDP-glucose at the plasma membrane surface in conjunction with an organized relationship between the synthase system and a specifically oriented glucosyl radical acting as an acceptor held on the membrane surface. An intact membrane is therefore necessary to direct synthesis for the beta-(1----4) bond by an enzyme that is capable of transglucosylation to the secondary alcoholic groups on C-2, C-3 or C-4 of the acceptor radical. The specificity of the system is controlled by the whole enzyme complex held on the membrane.