Constraining the formation and transport of lunar impact glasses using the ages and chemical compositions of Chang'e-5 glass beads.

Impact glasses found in lunar soils provide a possible window into the impact history of the inner solar system. However, their use for precise reconstruction of this history is limited by an incomplete understanding of the physical mechanisms responsible for their origin and distribution and possible relationships to local and regional geology. Here, we report U-Pb isotopic dates and chemical compositions of impact glasses from the Chang'e-5 soil and quantitative models of impact melt formation and ejection that account for the compositions of these glasses. The predominantly local provenance indicated by their compositions, which constrains transport distances to <~150 kilometers, and the age-frequency distribution are consistent with formation mainly in impact craters 1 to 5 kilometers in diameter. Based on geological mapping and impact cratering theory, we tentatively identify specific craters on the basaltic unit sampled by Chang'e-5 that may have produced these glasses and compare their ages with the impact record of the asteroid belt.

Age and composition of young basalts on the Moon, measured from samples returned by Chang'e-5.

Orbital data indicate that the youngest volcanic units on the Moon are basalt lavas in Oceanus Procellarum, a region with high levels of the heat-producing elements potassium, thorium, and uranium. The Chang'e-5 mission collected samples of these young lunar basalts and returned them to Earth for laboratory analysis. We measure an age of 1963 ± 57 million years for these lavas and determine their chemical and mineralogical compositions. This age constrains the lunar impact chronology of the inner Solar System and the thermal evolution of the Moon. There is no evidence for high concentrations of heat-producing elements in the deep mantle of the Moon that generated these lavas, so alternate explanations are required for the longevity of lunar magmatism.

Pb-Pb Dating of Terrestrial and Extraterrestrial Samples Using Resonance Ionization Mass Spectrometry.

We are developing an in situ, rock-dating spectrometer for spaceflight called the Chemistry, Organics, and Dating EXperiment (CODEX). CODEX will measure Rb-Sr compositions and determine ages of samples on the Moon or Mars and can be augmented to obtain Pb-Pb ages. Coupling Rb-Sr and Pb-Pb measurements broadens the suite of samples that can be dated and could provide tests of concordance. Here we assess whether geochronologically meaningful Pb-Pb data could be measured in situ by tuning the prototype CODEX to acquire Pb-Pb data from a suite of well-characterized specimens from the Earth, Moon, and Mars. For Keuhl Lake Zircon 91500 our 207Pb/206Pb age of 1,090 ± 40 Ma is indistinguishable from the accepted age. In each of the Martian meteorites we studied, we could not resolve more than a single component of Pb and could not uniquely determine ages; nevertheless, our isotopic measurements were consistent with most previous analyses. On the other hand, we uniquely determined ages for three lunar meteorites. Our age for MIL 05035 is 3,550 ± 170 Ma, within 2σ of published ages for this specimen, in spite of it having <1 ppm Pb. LAP 02205 was contaminated by terrestrial Pb, but by filtering our data to exclude the most contaminated spots, we obtained an age of 3,010 ± 70 Ma, coincident with published values. Finally, our age for NWA 032 is nearly 1,000 Ma older than its age determined from other isotopic systems and is supported by additional Pb measurements made after chemical leaching.

Chronology of martian breccia NWA 7034 and the formation of the martian crustal dichotomy.

Martian meteorite Northwest Africa (NWA) 7034 and its paired stones are the only brecciated regolith samples from Mars with compositions that are representative of the average martian crust. These samples therefore provide a unique opportunity to constrain the processes of metamorphism and alteration in the martian crust, which we have investigated via U-Pu/Xe, 40Ar/39Ar, and U-Th-Sm/He chronometry. U-Pu/Xe ages are comparable to previously reported Sm-Nd and U-Pb ages obtained from NWA 7034 and confirm an ancient (>4.3 billion years) age for the source lithology. After almost 3000 million years (Ma) of quiescence, the source terrain experienced several hundred million years of thermal metamorphism recorded by the K-Ar system that appears to have varied both spatially and temporally. Such protracted metamorphism is consistent with plume-related magmatism and suggests that the source terrain covered an areal extent comparable to plume-fed edifices (hundreds of square kilometers). The retention of such expansive, ancient volcanic terrains in the southern highlands over billions of years suggests that formation of the martian crustal dichotomy, a topographic and geophysical divide between the heavily cratered southern highlands and smoother plains of the northern lowlands, likely predates emplacement of the NWA 7034 source terrain-that is, it formed within the first ~100 Ma of planetary formation.

A nursing case management program for low-income high-risk diabetic clients: a projected cost-benefit analysis.

Case management has been widely promoted as a method that can improve clinical outcomes and reduce healthcare costs. This article describes a cost-benefit analysis for a proposed nursing case management program that provides care for a low-income high-risk diabetic population in a rural county. Industry trends, objectives and functions of the case management program, timeline, financial plan, and cost analysis are described. The analysis indicated a potential net savings of 149,544 dollars annually. This would be a significant cost savings for the healthcare provider and funding source.

Development of a nurse case management service: a proposed business plan for rural hospitals.

The nurse case management service (NCMS) for rural hospitals is an entrepreneurial endeavor designed to provide rural patients with quality, cost-effective healthcare. This article describes the development of an NCMS. A detailed marketing and financial plan, a review of industry trends, and the legal structure and risks associated with the development of the venture are presented. The financial plan projects a minimum savings of 223,200 dollars for rural institutions annually. To improve quality and reduce cost for rural hospitals, the authors recommend implementation of an NCMS.

Requirements and interventions used by BSN programs to promote and predict NCLEX-RN success: a national study.

The purposes of this study were (1) to identify specific program requirements and educational interventions used to promote National Council Licensure Examination-Registered Nurse (NCLEX-RN) success among graduates of Bachelor of Science in Nursing (BSN) programs and (2) to determine the best predictors of NCLEX-RN success used by BSN nursing programs. This descriptive correlational study used the survey method for data collection. Participants were recruited from 513 generic BSN programs. One hundred sixty usable responses were received for a response rate of 31.2 percent. This is the only recent national study of variables associated with NCLEX-RN success that could be found in the literature; therefore, it addresses a gap in the literature. Significant findings related to NCLEX passing rates included (1) the use of standardized entrance exams and Scholastic Aptitude Test (SAT) scores for admission criteria, (2) National League for Nursing (NLN) content at-risk scores for mental health and community health nursing for progression, (3) clinical proficiency and use of exit examinations as graduation requirements, (4) commercial reviews as an intervention, and (5) percent White as a demographic variable. Additionally, the findings support the use of standardized entrance examinations and content area examinations to assess readiness for NCLEX.

WEB-BASED GRADUATE EDUCATION IN RURAL NURSING CASE MANAGEMENT.

The decreasing supply of advanced practice nurses continues to be a problem that plagues America, especially in rural regions. It has been suggested that nurse educators aggressively recruit potential graduate students and provide "easy access" for nurses presently living and practicing in rural areas. Web-based or on-line courses not only improve access to graduate education for rural nurses but also provide for high quality teaching and learning experience for both students and faculty. The purpose of this study was to examine what students in a web-based graduate program in rural nursing case management and faculty perceive are the advantages and disadvantages of web-based learning. In this descriptive study, interviews and a written survey were used for data collection. The sample included six faculty teaching in the graduate nursing program at the time of data collection and 29 former students enrolled or graduated from the program. Findings revealed by students included difficulties with computer technology, unclear expectations for coursework, and lack of socialization as disadvantages. Students identified teacher advocacy and accessibility through distance education as advantages of the program. Faculty identified access as the major advantage. Disadvantages identified by faculty included lack of socialization for students, faculty workload, and a need for ongoing faculty development.