High-quality evidence from prospective longitudinal studies in humans is essential to testing hypotheses related to the developmental origins of health and disease. In this paper, the authors draw upon their own experiences leading birth cohorts with longitudinal follow-up into adulthood to describe specific challenges and lessons learned. Challenges are substantial and grow over time. Long-term funding is essential for study operations and critical to retaining study staff, who develop relationships with participants and hold important institutional knowledge and technical skill sets. To maintain contact, we recommend that cohorts apply multiple strategies for tracking and obtain as much high-quality contact information as possible before the child’s 18th birthday. To maximize engagement, we suggest that cohorts offer flexibility in visit timing, length, location, frequency, and type. Data collection may entail multiple modalities, even at a single collection timepoint, including measures that are self-reported, research-measured, and administrative with a mix of remote and in-person collection. Many topics highly relevant for adolescent and young adult health and well-being are considered to be private in nature, and their assessment requires sensitivity. To motivate ongoing participation, cohorts must work to understand participant barriers and motivators, share scientific findings, and provide appropriate compensation for participation. It is essential for cohorts to strive for broad representation including individuals from higher risk populations, not only among the participants but also the staff. Successful longitudinal follow-up of a study population ultimately requires flexibility, adaptability, appropriate incentives, and opportunities for feedback from participants.

Understanding place-based contributors to health requires geographically and culturally diverse study populations, but sharing location data is a significant challenge to multisite studies. Here, we describe a standardized and reproducible method to perform geospatial analyses for multisite studies. Using census tract-level information, we created software for geocoding and geospatial data linkage that was distributed to a consortium of birth cohorts located throughout the USA. Individual sites performed geospatial linkages and returned tract-level information for 8810 children to a central site for analyses. Our generalizable approach demonstrates the feasibility of geospatial analyses across study sites to promote collaborative translational research.

In recent years, a variety of efforts have been made in political science to enable, encourage, or require scholars to be more open and explicit about the bases of their empirical claims and, in turn, make those claims more readily evaluable by others. While qualitative scholars have long taken an interest in making their research open, reflexive, and systematic, the recent push for overarching transparency norms and requirements has provoked serious concern within qualitative research communities and raised fundamental questions about the meaning, value, costs, and intellectual relevance of transparency for qualitative inquiry. In this Perspectives Reflection, we crystallize the central findings of a three-year deliberative process—the Qualitative Transparency Deliberations (QTD)—involving hundreds of political scientists in a broad discussion of these issues. Following an overview of the process and the key insights that emerged, we present summaries of the QTD Working Groups’ final reports. Drawing on a series of public, online conversations that unfolded at www.qualtd.net, the reports unpack transparency’s promise, practicalities, risks, and limitations in relation to different qualitative methodologies, forms of evidence, and research contexts. Taken as a whole, these reports—the full versions of which can be found in the Supplementary Materials—offer practical guidance to scholars designing and implementing qualitative research, and to editors, reviewers, and funders seeking to develop criteria of evaluation that are appropriate—as understood by relevant research communities—to the forms of inquiry being assessed. We dedicate this Reflection to the memory of our coauthor and QTD working group leader Kendra Koivu.1

Glaciated valleys of the Dalton Range in the south-west Yukon Territory are dominated by rock glaciers identified as glacier ice-cored debris systems. The two rock glaciers studied have different amounts of deformation at present, resulting from post-formation mechanics.

The primary formation of lobes of the rock glaciers resulted from periods of glacier activity in the Neoglacial, although older lobes, probably late Pleistocene in age, occur below the Neoglacial lobes. The hydrological systems of the rock glaciers have played a major role in the post-formation deformation of the land forms and the present drainage system is entirely sub-surface. The explanation for the extensive occurrence of rock glaciers in the Dalton Range is lithological as a result of the high susceptibility of the Upper Jurassic/Lower Cretaceous sediments to frost action and glacier erosion.

Background: Historically, cash interventions, as opposed to material or in-kind aid, have been relatively uncommon in the humanitarian response to emergencies. The widespread implementation of cash-based programs following the 2004 Indian Ocean tsunami provided an opportunity to examine cash distributions following disasters. The Mercy Corps cash grant program in Aceh, Indonesia, was a short-term intervention intended to assist in recompensing losses from the December 2004 tsunami.

Methods: An evaluation of the Mercy Corps cash grant program was conducted for the 12-month period following the tsunami using program monitoring data and a systematic survey of cash grant beneficiaries.

Results: in 2005, the cash grant program disbursed more than US$3.3 million to more than 53,000 beneficiaries; the average cash grant award was US$6390, which was shared by an average of 108 beneficiaries. In a beneficiary survey, more than 95% of respondents reported the grant allocation processes were fair and transparent and that grant funds were received.

Conclusions: The Mercy Corps experience with cash programs suggests that cash interventions in the emergency context, when properly administered, can have an immediate impact and serve as an efficient mechanism for providing assistance. Organizations involved in humanitarian relief, particularly donors and nongovernmental organizations, should consider incorporating cash-based interventions as an element of their response in future emergencies. (Disaster Med Public Health Preparedness. 2008;2:95–103)

Objective: Effective communication is recognized as an essential process to providing quality care, including palliative and end-of-life care. Discussion of prognosis and support needs of patients with heart failure is particularly challenging given the nature of the condition and care across several settings. The objective was to design, implement, and evaluate an interdisciplinary workshop aimed at improving attitudes and skills related to communication with patients and family, health team communication and documentation, and assessment of physical and emotional symptoms.

Methods: A pretest, delayed posttest evaluation design was used to evaluate two 4-h workshops offered to nurses, social workers, and other nonphysician clinicians.

Results: Although baseline reports of skills were high for the participants, significant improvement was noted for objectives emphasized in the workshop.

Significance of results: This project demonstrated the feasibility of designing, marketing a brief workshop, and positively impacting communication and documentation skills.

Somatic cells of Armillaria gallica fruit bodies have been shown to possess different genotypes for molecular-marker and mating-type loci. Here we report experiments on six quantitative traits and demonstrate that somatic cells of fruit bodies possess almost as much genetic variation for growth rate and phenotypic plasticity as do spores, the products of meiosis. Genetically distinct somatic cells therefore have the potential to grow at different rates relative to one another during primordial fruit body formation. This may confer an advantage on all cell lines within a fruit body, not just those that happen to grow better under a particular set of conditions. To our knowledge, genetic variation for fitness-related traits that make up a single genetic individual has not been reported before.

The history of school reform has continuously fascinated historians of education, but their study of the subject has acquired a new urgency in the last quarter of a century as national political discussions have given an increasingly important place to educational policy. The recent publication of Tinkering toward Utopia: A Century of Public School Reform (Harvard University Press, 1995), by David Tyack and Larry Cuban, offers the latest comprehensive study of the subject. We have invited four distinguished scholars to comment on the book. They are Robert L. Hampel of the University of Delaware, William R. Johnson of the University of Maryland, Baltimore County, David N. Plank of Michigan State University, and Diane Ravitch of the Brookings Institute. Professors Tyack and Cuban have, in turn, agreed to respond to the comments.

Corresponding to every graph, bipartite graph, or directed bipartite graph there exists a directed graph which is connected if and only if the original graph is connected.

In this paper, it is shown that for every directed graph there exists a certain bipartite graph such that the directed graph is connected if and only if the bipartite graph is irreducible. Other connections between reducibility and connectivity are established.

Euler (6) in 1782 first studied orthogonal latin squares. He showed the existence of a pair of orthogonal latin squares for all odd n and conjectured their non-existence for n = 2(2k + 1). MacNeish (8) in 1921 gave a construction of n — 1 mutually orthogonal latin squares for n = p with p prime and of n(v) mutually orthogonal squares of order v where

with p1 p2, … , Pr being distinct primes and

In [1] G. Birkhoff stated an algorithm for expressing a doubly stochastic matrix as an average of permutation matrices. In this note we prove two graphical lemmas and use these to find an upper bound for the number of permutation matrices which the Birkhoff algorithm may use.

A doubly stochastic matrix is a matrix of non-negative elements with row and column sums equal to unity and is there - fore a square matrix. A permutation matrix is an n × n doubly stochastic matrix which has n2-n zeros and consequently has n ones, one in each row and one in each column. It has been shown by Birkhoff [1],Hoffman and Wielandt [5] and von Neumann [7] that the set of all doubly stochastic matrices, considered as a set of points in a space of n2 dimensions constitute the convex hull of permutation matrices.