National Research Council Report Research Articles

Phenanthroline Catalysis in Stereoselective 1,2-cis Glycosylations.

The National Research Council's report in 2012 recognized glycosidic bond forming (glycosylation) reactions as critical due to the central importance of carbohydrates to the glycosciences. This report emphasized the need for the development of reproducible and broadly applicable glycosylation technologies to facilitate the stereoselective synthesis of biomedically relevant glycan libraries for tool development and for research applications by nonspecialists. In response to this report with NIH Common Fund support, the publications of new catalytic diastereoselective glycosylation protocols, some with broad generality under mild conditions, have been recently reported by our group and others. These recent discoveries have also advanced the understanding of the glycosylation reaction mechanism involving the coupling of a sugar electrophile bearing a leaving group at its C1-anomeric center with an alcohol nucleophile. This glycosidic bond forming reaction can lead to a mixture of two stereoisomers that differ in the configuration of the anomeric center.In our group, we discovered that readily available phenanthroline, a rigid and planar organic compound with two fused pyridine rings, could be utilized as a nucleophilic catalyst to promote highly diastereoselective glycosylation of an alcohol nucleophile with a sugar bromide electrophile. The phenanthroline catalysis process allows access to a myriad of high yielding and diastereoselective 1,2-cis pyranosides and furanosides. This catalyst-controlled approach has been applied to the synthesis of a potential vaccine adjuvant α-glucan octasaccharide. For pyranosyl bromide electrophiles, an extensive mechanistic investigation illustrated that two phenanthrolinium ion intermediates, a 4C1 chair-liked equatorial-conformer and a B2,5 boat-like axial-conformer, are formed in a ratio of 2:1 (equatorial/axial). To obtain high levels of axial-1,2-cis selectivity, a Curtin-Hammett scenario was proposed wherein interconversion of the 4C1 equatorial-conformer and B2,5 axial-conformer is more rapid than nucleophilic addition. Hydroxyl attack takes place from the axial-face of the more reactive 4C1 chairlike equatorial intermediate to afford an axial-1,2-cis glycoside product. The phenanthroline catalysis system is applicable to a number of furanosyl bromide electrophiles to provide the challenging 1,2-cis substitution products in good yield and diastereoselectivity. NMR experiments and density-functional theory (DFT) calculations support an associative mechanism in which the rate-determining step takes place from an invertive displacement of the faster reacting furanosyl phenanthrolinium ion intermediate with an alcohol nucleophile. Overall, this work stands at the underdeveloped intersection of operationally simple conditions, catalysis, and stereocontrolled glycosidic bond formation, each of which represents an important theme in the preparation of biologically important oligosaccharides and glycopeptides for applications to human health and medicine.

Standardized Procedure of Measuring the pH Value of Cement Matrix Material by Ex-Situ Leaching Method (ESL)

According to the Spanish National Research Council (CSIC) report, the ex-situ leaching method (ESL) is more appropriate and accurate than other methods for measuring pH value in terms of repeatability and reproducibility. In this study, the ESL method was used to measure the pH value of cement matrix materials. The design test process aimed to avoid underestimating the variation in pH during the process of solution stirring and pH measurement without using both argon and nitrogen to block the specimen contact with air, with good repeatability and reproducibility. This study also considered the influence of the dryness of the specimen before crushing, the size of the powder, the air-exposed specimen, the air-exposed solution, the temperature of the solution, etc. After testing and analysis, a standard procedure for detecting the pH value of cement matrix materials was established which is known as the S-ESL method.

Introduction to Special Issue on Risk Assessment, Economic Evaluation, and Decisions.

Integrating risk assessment, economic evaluation, and uncertainty to inform policy decisions is a core challenge to risk analysis. In September 2019, the Harvard Center for Risk Analysis, with support from the Society for Risk Analysis Economics and Benefits Analysis Specialty Group and others, convened a workshop to address this issue. The workshop built in part on the recommendations of the 2009 National Research Council report, Science and Decisions: Advancing Risk Assessment. It honored John S. Evans, whose thoughtful and innovative teaching and scholarship have significantly advanced thinking on these issues. This special issue features a profile of Dr. Evans and nine articles that build on work presented at the workshop.

Human-assisted Sample Return Mission at the Schrödinger Basin, Lunar Far Side, Using a New Geologic Map and Rover Traverses

Abstract The Schrödinger basin on the south polar lunar far side has been highlighted as a promising target for future exploration. This report provides a high-resolution geologic map in the southwest peak-ring (SWPR) area of the Schrödinger basin, emphasizing structural features and detailed mapping of exposed outcrops within the peak ring. Outcrops are correlated with mineralogical data from the Moon Mineralogical Mapper instrument. Geologic mapping reveals a complex structural history within the basin through a system of radially oriented faults. Further, the geologic map shows both faulted and magmatic contacts between peak-ring mineralogies, providing both structural and magmatic context for understanding lunar crustal evolution and polar region processes. To investigate these relationships and address key scientific concepts and goals from the National Research Council (NRC) report, we propose three traverse paths for a robotic sample return mission in the SWPR area. These traverses focus on addressing the highest priority science concepts and goals by investigating known outcrops with diverse mineralogical associations and visible contacts among them. Coinciding with the preparation for the 2024 Artemis III mission, NASA is increasing the priority of robotic exploration at the lunar south pole before the next crewed mission to the Moon. Through mapping the Schrödinger SWPR, we identified the extent of different lunar crustal mineralogies, inferred their geologic relationships and distribution, and pinpointed traversable routes to sample spectrally diverse outcrops and outcrop-derived boulders. The SWPR region is therefore a promising potential target for future exploration, capable of addressing multiple high-priority lunar science goals.

The American Chemical Society General Chemistry Performance Expectations Project: From Task Force to Distributed Process for Implementing Multidimensional Learning

This contribution reports the process and outcomes of a multiyear effort that supported institutions in reforming general chemistry using multidimensional learning approaches in the form of performance expectations. Performance expectations are based on evidence-centered assessment design principles and describe what learners should be able to do with their knowledge, a subtle (but profound) shift from traditional course learning goals. The effort grew from the recommendations of a task force appointed in 2015 by the American Chemical Society’s Division of Chemical Education and Society Committee on Education. This task force recommended a participatory process for creating general chemistry performance expectations that was distributed over, and also coordinated across, multiple institutions. With support from the ACS Education Division, this recommendation was enacted through workshops which supported faculty in developing activities and assessments that integrated content, science and engineering practices, and cross-cutting concepts—a three-dimensional structure based on the National Research Council report A Framework for K-12 Education. From these workshops, a group of faculty committed to implementing three-dimensional performance expectations in their courses evolved. In practice, these faculty found that their institutional work resulted in designing learning performances that, while also three-dimensional, were of narrower content focus than is typical of performance expectations. This development process also led faculty to use the structures of evidence-centered design and multidimensional learning to document learning activity designs in new ways, generating a consensus activity structure. As examples of how faculty used this consensus activity structure as a new way to examine student learning and performances, development artifacts from four of the participating institutions is presented.

Advances toward validating examiner writership opinion based on handwriting kinematics

A National Research Council report on strengthening forensic science raised concern over the lack of scientific studies supporting the validity of examining and interpreting forensic evidence. However, establishing the foundational validity of subjective methods can be challenging. The present study aimed to establish the scientific validity of expert writership opinions and the two-stage approach to evidence interpretation using measures derived from research on handwriting motor control. Regression-based procedures were used to address two experimental questions: 1) what are the relative contributions of kinematic and pressure features in predicting examiner support for alternate writership propositions when examining pairs of questioned handwriting samples; and 2) to what extent does information about the rarity of the kinematic feature dissimilarity scores improve the accuracy of a predictive model based on dissimilarity alone. Regarding the first question, we identified a multifactor model consisting of feature dissimilarity scores and their population distributions having correlation coefficients (R2) of 0.84 and 0.88 for the same-writer and different-writers propositions, respectively. Temporal features contributed up to 21% to the predictive value of the model, whereas spatial features contributed only 9% and pen pressure contributed up to 17%. When we compared models reflecting a single-stage process (based on feature dissimilarities) of forming opinions with models reflecting a two-stage process (based on feature dissimilarities and rarity) we found that the two-stage models had an average of 15.25% greater predictive value than single-stage models. These findings support the scientific validity of FDE writership determinations and underscore the importance of the two-stage approach for evidence interpretation.

Forty Years of Food Safety Risk Assessment: A History and Analysis.

Before the founding of the Society for Risk Analysis (SRA) in 1980, food safety in the United States had long been a concern, but there was a lack of systematic methods to assess food-related risks. In 1906, the U.S. Congress passed, and President Roosevelt signed, the Pure Food and Drug Act and the Meat Inspection Act to regulate food safety at the federal level. This Act followed the publication of multiple reports of food contamination, culminating in Upton Sinclair's novel The Jungle, which highlighted food and worker abuses in the meatpacking industry. Later in the 20th century, important developments in agricultural and food technology greatly increased food production. But chemical exposures from agricultural and other practices resulted in major amendments to federal food laws, including the Delaney Clause, aimed specifically at cancer-causing chemicals. Later in the 20th century, when quantitative risk assessment methods were given greater scientific status in a seminal National Research Council report, food safety risk assessment became more systematized. Additionally, in these last 40 years, food safety research has resulted in increased understanding of a range of health effects from foodborne chemicals, and technological developments have improved U.S. food safety from farm to fork by offering new ways to manage risks. We discuss the history of food safety and the role risk analysis has played in its evolution, starting from over a century ago, but focusing on the last 40 years. While we focus on chemical risk assessment in the U.S., we also discuss microbial risk assessment and international food safety.

Evaluating Likelihood Ratio (LR) for firearm evidence identifications in forensic science based on the Congruent Matching Cells (CMC) method

Firearm evidence identification has been challenged by the 2008 and 2009 National Research Council (NRC) reports and by legal proceedings on its fundamental assumptions, its procedure involving subjective interpretations, and the lack of a statistical foundation for evaluation of error rates or other measures for the weight of evidence. To address these challenges, researchers of the National Institute of Standards and Technology (NIST) recently developed a Congruent Matching Cells (CMC) method for automatic and objective firearm evidence identification and quantitative error rate evaluation. Based on the CMC method, a likelihood ratio (LR) procedure is proposed in this paper aiming to provide a scientific basis for firearm evidence identification and a method for evaluation of the weight of evidence. The initial LR evaluations using two sets of 9mm cartridge cases’ breech face impression images with different sample sizes, imaging methods and ammunition showed that for all the declared identifications of the tested 2D and 3D image pairs, the evaluated LRs for the least favorable scenario were well above an order of 106, which provides Extremely Strong Support for a prosecution proposition (e.g. a same-source proposition) in a Bayesian frame. The LR evaluations also showed that for all the declared exclusions of the tested 3D image pairs, the evaluated LRs for the least favorable scenario were above an order of 102, which provides Moderately Strong Support for a defense proposition (e.g. a different-source proposition) in a Bayesian frame.

O PAPEL DO PENSAMENTO ESPACIAL NA CONSTRUÇÃO DO RACIOCÍNIO GEOGRÁFICO


 
 
 
 Nos últimos anos o pensamento espacial foi incorporado como temática a ser estudada na educação geográfica brasileira, o que nos recobrou enorme responsabilidade teórica e metodológica no movimento de compreendermos em que medida ele pode ser uma habilidade a ser desenvolvida e de que modo ele atua como dimensão participante na construção do raciocínio geográfico. Partimos das definições das teorias que fundam o pensamento espacial (GOLLEDGE & SPECTOR, 1978 , LIBEN & DOWNS, 1989, TVERSKY, 1981, entre outros) antes de sua síntese no relatório do National Research Council (2006) para elaborar um relacionamento entre os campos de conhecimentos coerente diante da geografia brasileira e das necessidades que nossos professores e jovens têm, defendendo o pensamento espacial como um conteúdo procedimental-conceitual (Zabala, 1999). Apresentaremos por fim essa ideia dialogando diferentes campos epistêmicos e situações, como possibilidade de contribuição teórica e prática para a Educação Geográfica, reforçando a linguagem cartográfica, os sujeitos, suas ações e seus lugares no mundo como parte intrínseca do processo de ensino- aprendizagem em Geografia.
 Palavras-chave
 Educação Geográfica, Raciocínio Geográfico, Cartografia Escolar, Situação Geográfica, Cognição
 
 
 

Reevaluating Polyunsaturated Fatty Acid Essentiality in Rainbow Trout

AbstractThe National Research Council (NRC) reports that the essential fatty acid requirements of Rainbow Trout Oncorhynchus mykiss can be satisfied by 0.7–1.0% 18:3(n‐3) or 0.4–0.5% n‐3 long‐chain (LC) polyunsaturated fatty acids (PUFAs; defined by NRC as 20:5[n‐3] + 22:6[n‐3]) in the diet. These requirements were defined roughly 50 years ago and do not consider the importance of n‐6 PUFAs in the diet. Therefore, we assessed survival, growth performance, and tissue fatty acid composition of juvenile Rainbow Trout (mean initial weight ± SE = 24.6 ± 0.1 g; 10 fish/tank, 4 tanks/diet) that were fed experimental diets (53% protein; 13% lipid) containing fish oil, fully hydrogenated soybean oil, or fully hydrogenated soybean oil with five different combinations of fatty acid ethyl esters (18:2[n‐6], 18:3[n‐3], 20:4[n‐6], 20:5[n‐3], and 22:6[n‐3]) to illuminate the relative essentiality of n‐3 and n‐6 PUFAs. Final individual weight (78.2–132 g), weight gain (216–433%), feed conversion ratio (0.93–1.42), specific growth rate (2.05–2.98% body weight/d), and hepatosomatic index (1.4–2.1) were significantly affected by dietary treatment whereby Rainbow Trout that received the fish oil‐based diet outperformed all other treatments. Growth of fish that were given different combinations of fatty acid ethyl esters was not statistically different. Fatty acid tissue composition generally reflected dietary treatment, with the greatest profile changes observed in intraperitoneal fat, fillet, and liver and the smallest changes occurring in brain and eye tissues. Results largely validate previous reports indicating that Rainbow Trout are physiologically able to synthesize LC‐PUFAs from C18 PUFAs and therefore do not necessarily require LC‐PUFA‐rich feeds. However, numeric increases in the growth of Rainbow Trout suggest that this species achieves an energetic advantage if offered n‐3 and n‐6 LC‐PUFAs in the diet.

Toxicity testing in the 21st century: progress in the past decade and future perspectives.

Advances in the biological sciences have led to an ongoing paradigm shift in toxicity testing based on expanded application of high-throughput in vitro screening and in silico methods to assess potential health risks of environmental agents. This review examines progress on the vision for toxicity testing elaborated by the US National Research Council (NRC) during the decade that has passed since the 2007 NRC report on Toxicity Testing in the 21st Century (TT21C). Concomitant advances in exposure assessment, including computational approaches and high-throughput exposomics, are also documented. A vision for the next generation of risk science, incorporating risk assessment methodologies suitable for the analysis of new toxicological and exposure data, resulting in human exposure guidelines is described. Case study prototypes indicating how these new approaches to toxicity testing, exposure measurement, and risk assessment are beginning to be applied in practice are presented. Overall, progress on the 20-year transition plan laid out by the US NRC in 2007 has been substantial. Importantly, government agencies within the United States and internationally are beginning to incorporate the new approach methodologies envisaged in the original TT21C vision into regulatory practice. Future perspectives on the continued evolution of toxicity testing to strengthen regulatory risk assessment are provided.

Imprisonment, opioids and health care reform: The failure to reach a high-risk population

The 2014 National Research Council report on American incarceration optimistically anticipated the Affordable Care Act (ACA) would be “a turning point in the nation's health care, and … will provide unprecedented access to care for many people being released from correctional facilities.” However, the ACA was not designed to proactively respond to risks associated with prisoner re-entry into society. Our overarching hypothesis is that unmet health needs among previously incarcerated adults can be more fully understood by analyzing how un-prescribed use of drugs, such as opioids, is associated with economic and health problems and health care un-insurance that in turn results in exclusion from needed health care services. Using several waves of the National Longitudinal Study of Adolescent to Adult Health conducted before and after passage and implementation of ACA, our analysis indicates that the above risk factors nearly fully mediate the association between previous incarceration and failure to receive needed health care. We argue that these factors are likely intensified by a reactive approach to health care reform that not only fails to cover many former prisoners, but also is lacking in sufficient outreach programming, and as such is insufficient for adults with health problems and limited economic resources - especially those using un-prescribed opioids. Future work should address the capacity of more proactively organized public health programs to expand coverage to previously incarcerated populations - including un-prescribed opioid users - and thereby reduce their health risks and vulnerability to repeated exposure to law enforcement surveillance and criminal punishment.

Projekt "Mapowanie odbitek linii papilarnych" (część I) - geneza

Since the publication of the National Research Council Report titled: Strengthening Forensic Science in the United States: A Path Forward for the United States Department of Justice, there has been an international discussion on scientific character of fingerprint examination, and Poland has not been excluded from it. The approaches to fingerprint identification in the United States of America and Poland are completely different. In the first case, the holistic standard is used basing exclusively on the experience and conviction of the expert, and in the other one, numerical standard precisely determining the minimum number of consistent individual characteristics (minutiae) required for identification. Both standards have both advantages and significant drawbacks. A good way out of this situation would be finding a solution combing the holistic and numerical approaches and the project “Mapping of friction skin ridges impressions” implemented by the forensic experts of Fingerprint Examination Department in the Central Forensic Laboratory of the Police makes constitutes contribution to that.

When Is Science Used in Science Policy? Examining the Importance of Scientific and Technical Information in National Research Council Reports

AbstractA frequent lament among researchers is that public policy makers should pay more attention to scientific and technical information (STI). If there is any single area where one might expect STI to be used in public policy making and agenda setting it is in science and technology policy. Many of the policy makers in science and technology policy are themselves scientists or researchers and presumably would prove especially receptive to STI. However, STI is only one of many types of information used in policy making and policy actors often differ in the extent to which they view STI as credible, particularly compared to other types of potentially policy‐relevant information. Research on credibility (the believability of information, information types, and media) has shown variance and policy makers’ “credibility maps.” Thus, some policy makers have preference for formal information generally and STI specifically, but others privilege raw data, personal experience, authority, history and anecdote, analogical reasoning, or conformance to ideology, to name just a few of the information choices. Here, we build on the current researchers’ previous bibliometrics‐based work and use data from 41 semi‐structured elite interviews with National Research Council (NRC) executives and staff and NRC committee members concerning the use of STI in reports issued by the NRC. Findings show that the use of STI in NRC reports varies according to the nature of the inquiry and the sponsor. Information used in the reports is based on not only the assessed credibility of information but also its perceived direct relevance and the availability of STI as compared to other types of information. In general, the amount of STI in the NRC reports tends to have modest effects on the likelihood that reports will be used in policy making or by the mass media. More important factors include the timing of the report with respect to political agendas, the party requesting the report, and the enacted roles of NRC staff members and committee chairs.

Constructing Legitimacy in Geoengineering Discourse: The Politics of Representation in Science Policy Literature

ABSTRACTGeoengineering, the idea of addressing climate change through large-scale technological projects, is a unique example of a contested emerging technology. It stands out in the degree to which both its scope of possibilities and its premise are characterized by global existential risks. Despite controversy due to inherent and perceived risks, this field has been shifting toward mainstream consideration. Geoengineering science policy reports reflect this shift and influence the subsequent trajectory of research and potential deployment. The two most notable geoengineering policy reports are those by the Royal Society in 2009 and the National Research Council (NRC) in 2015. Discursive strategies recurrent in these reports construct notions of legitimacy and normalcy in regard to geoengineering. These strategies include relative legitimation of actors and approaches, differentiating research from deployment, elevating particular geoengineering methods through comparative evaluation, and normalizing novel geoengineering proposals through analogy. These strategies are present in both the benchmark geoengineering policy reports, with a deepening and entrenchment evident in the later NRC report. Together, these discursive strategies promote the legitimization of geoengineering research.

How explicit is the cognitive science foundation of geoscience education research? A study of syntactical units in JGE articles

ABSTRACTThe National Research Council's report, Discipline-Based Education Research: Understanding and Improving Learning in Undergraduate Science and Engineering (Singer, Nielsen, & Schweingruber, 2012), states that discipline-based education research (DBER), such as geoscience education research (GER), is informed by research about cognition and learning. It also states that how different disciplines ground their DBER in existing cognitive theories of learning varies. The aim of this study is to take a first step toward systematically evaluating the degree to which research on undergraduate geoscience education published in the Journal of Geoscience Education (JGE) is informed by cognitive science concepts and grounded in cognitive learning theories. This study's theoretical framework draws on a linguistic theory of representation and a general cognitive theory of learning. The methodology of a systematic literature review was used to examine 1,760 articles published in JGE from 1985 to 2016. Of these articles, 167 articles met the selection criteria (undergraduate geoscience education research) for further appraisal. The results of this study suggest that undergraduate geoscience education scholars (a) have an ongoing interest in cognition-related research topics, (b) have an overall low degree of fluency or familiarity with cognitive science concepts, and (c) can further future GER studies in cognitive learning theories. Recommendations based on this study's findings include independently learning more about cognition, developing partnerships or collaborations with those more knowledgeable about cognitive concepts and theories, and supporting one another in the GER community to increase fluency with cognitive science concepts and increasingly incorporate theoretical frameworks into future GER studies.

Gas Chromatography-Mass Spectrometer (GC/MS): In Scientific Evidence, Even 'Gold Standard' Techniques Have Limitations

There is an emerging view that there are two types of forensic science: “junk” science such as forensic odontology (bitemark analysis) and “real” science such as nuclear DNA typing. The 2009 National Research Council report contributed to the emergence of this view. On the one hand, the report was sharply critical of techniques such as bitemark analysis. On the other hand, the report had high praise for techniques such as the DNA typing identification technique and gas chromatography/mass spectrometry (GC/MS) as an elemental analysis methodology. The courts are becoming increasingly skeptical about “junk” science techniques. In some instances, they are excluding testimony based on such techniques. In other cases, they are severely restricting the wording of the opinions based on such techniques that experts may testify to. However, in the case of “real” science, the courts tend to assume reliability. In particular, the courts have come to view nuclear DNA typing and GC/MS analysis as the “gold standards” of forensic science. The courts routinely admit testimony about nuclear DNA typing, and one court has gone to the length of declaring that GC/MS analysis is “nearly infallible.” However, the 2016 President’s Council of Advisors on Science and Technology report raised questions about one “gold standard,” DNA analysis. The PCAST report questioned the validity of the traditional methods of analyzing mixed DNA samples. The report faulted those methods as unduly subjective. In addition, many commentators have challenged the validity of Low Copy Number (LCN) testing of minute or “touch” DNA samples. Although the New York have admitted testimony about LCN analysis, many other courts have barred such testimony. The thesis of this article is that like nuclear DNA testing, GC/MS analysis has important limitations. The article explains that when GC/MS is used in drug testing, the court must inquire as to the mode of analysis: full scan, selective ion reliance, or selective ion monitoring. The article adds that when GC/MS is employed to identify ignitable liquids in arson investigations, the court should inquire as to the condition of the sample tested: Has it been subjected to weathering, microbial degradation, or pyrolysis? It is certainly justifiable to subject “junk” science to more intense scrutiny. However, the courts should not naively assume that GC/MS is “nearly infallible.” In forensic science, even “gold standard” techniques have significant limitations.

Repeatability and reproducibility of forensic likelihood ratio methods when sample size ratio varies

Existing statistical methods for estimating the log-likelihood ratio from biometric scores include parametric estimation, kernel density estimation, and recently adopted logistic regression estimation. There has been a growing interest to study the repeatability and reproducibility of these methods on biometric datasets after the 2009 National Research Council report [15] and the 2016 President's Council of Advisors on Science and Technology report [1]. For a statistical forensic evaluation method to be repeatable, it needs to generate consistent log-likelihood ratios for various sample size ratios between the genuine (mated) and imposter (non-mated) scores from the same database. It is a well known fact, that for logistic regression methods, the estimated intercept value depends on the sample size ratio between the two groups. Therefore, when computing log-likelihood ratios using logistic regression estimation, different genuine and impostor sample size ratios could result in different log-likelihood ratio values. We performed extensive simulations and used face and fingerprint biometric datasets to investigate repeatability and reproducibility of existing log-likelihood ratio estimation methods.

Formative Analysis of Aging in Place: Implications for the Design of Caregiver Robots

Many have conceptualized caregiver robots as consumer products and studied elders’ perceived needs afor and preferences about such products. For reviews, please see (Broadbent, Stafford, & MacDonald, 2009; Jones & Schmidlin, 2011). That approach, though, could create robots that cannot satisfy elders’ actual caregiving needs. Alternatively, one can conceptualize caregiver robots as workers in complex socio-technical systems. To do so, one would need a detailed account of the caregiving that takes place in elders’ homes. Unfortunately, as noted in a National Research Council (2011) report, such a detailed account of caregiving does not exist. Accordingly, we sought to develop such an account. There are many ways to analyze work (for a discussion of general approaches, see Vicente, 1999). They can be categorized into 3 general types: normative, descriptive, and formative approaches (Vicente, 1999). We adopted a formative approach because formative approaches are tailored to the analysis of complex socio-technical systems (Vicente, 1999). They capture work requirements without specifying how that work must be done or who must do it. For example, the constraint “must not lose track of time” captures a work requirement but allows the associated work to be accomplished in a number of different ways (e.g., by checking a clock, setting an alarm) and by a number of different entities (e.g., family member, caregiver robot). To conduct our analysis, researchers observed caregiving in elders’ homes, and interviewed caregivers about their work activities. Researchers then organized their findings into an Abstraction Hierarchy (AH; Vicente, 1999), that is, a detailed account of the aging in place socio-technical system. Our primary aim was to create an AH that describes means-ends relations between the complex socio-technical caregiving system’s overall objectives, work tasks, and physical resources. Such a description provides a detailed account of the caregiving work domain, and serves as the foundation for subsequent formative analyses of caregiving. To create the AH, research team members completed 4 steps: 1) analyzing existing caregiving documentation, 2) observing caregiving and interviewing caregivers, 3) drafting and/or refining the AH, and 4) validating the AH. Steps 2 and 3 were iterative. This process is consistent with Naikar, Hopcraft, and Moylan’s (2005) recommendations regarding formative analyses. The AH made clear that caregiving for those who age in place is a complex and nuanced activity. More specifically, our analysis confirmed existing research regarding categories of caregiving tasks and revealed aspects of caregiving that have not been detailed so far. The existing literature indicates that caregivers assist older adults with self-maintenance activities of daily life (ADLs), such as eating, toileting, and dressing (Lawton, 1990), instrumental activities of daily life (IADLs), such as cooking, cleaning, and shopping (Lawton, 1990), and enhanced activities of daily life (EADLs), such as participating in social activities and pursuing hobbies (Rogers, et al., 1998). Our analysis confirmed those findings, and our AH provides a more detailed account of those tasks than was previously available. Our analysis also revealed aspects of caregiving for those who are aging in place that have not been detailed thus far in the research literature. For example, our AH contains a purpose-related function called Counseling, which concerns ensuring that the elder does not experience psychological distress. To perform this function, the caregiver must understand the elder’s situation (e.g., a family conflict), use information about that situation (e.g., experience with relevant family members and/or past conflicts; the elders’ past choices), and offer the elder advice about how to proceed (e.g., which family member’s advice to follow). The main implication of our AH for the design of caregiver robots is that such robots cannot be designed to perform purpose-related functions in a one-size-fits-all way; rather, caregiver robots must exhibit context-conditioned variability (Vicente, 1999). Our AH has many other important implications for the design of caregiver robots, which unfortunately cannot be detailed here due to space constraints.

Estimands and Their Role in Clinical Trials

ABSTRACTThe National Research Council (NRC) highlighted the need to more clearly distinguish between the target of estimation (“estimand”) and the method of estimation (“estimator”) in clinical trials. While the NRC report on “The Prevention and Treatment of Missing Data in Clinical Trials” focuses on issues arising due to missing data, a framework to coherently align trial objectives and corresponding estimands is valuable in a broader sense. The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) has reinforced this by tasking a working group to develop an addendum to the ICH-E9 guideline “Statistical Principles for Clinical Trials.” In this article, we motivate the need for change, propose a structured framework to bridge trial objectives with proper inference tools, and discuss how it may impact the role of statisticians involved in clinical trial design and analysis.