After decades of study, much remains unknown about the foraging practices of the earliest inhabitants of Puerto Rico. Here, we present an analysis of the malacological assemblages of two neighboring and (partially) contemporary early sites from the island's southwest, finding intriguing intersite differences in shellfish collection practices. We attribute this diversity to differences in site type, chronology, or changes in local coastal configuration. This work not only provides insights into prehistoric Puerto Rican foraging dynamics but also demonstrates the importance of considering factors including intra-age chronology, site type, and changes in paleoenvironmental conditions when considering ancient foraging practices.

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

A growing body of evidence suggests that synaptic plasticity is involved in addictive behaviour and nicotine dependence (ND). Neurotrophic factors, such as neurotrophin 3 (NT3) play a key role in modulating neuronal plasticity. Therefore, an association between nicotine, smoking and neurotrophic factors has been suggested. However, the role of NT3 in ND has not been thoroughly investigated in humans so far.

We investigated the influence of chronic (long-term smoking) and acute nicotine administration on the plasma level of NT3. We measured plasma NT3 levels at baseline and then 15 and 45 minutes after nicotine or placebo administration using an enzyme-linked-immunoabsorbent-assay (ELISA). Smokers showed higher NT3 level than non-smokers at baseline. Interestingly, 15 minutes after acute nicotine injection, plasma level of NT3 in both smokers and non-smokers decreased significantly and went back to baseline levels after 30 minutes. We found that plasma nicotine and NT3 levels were positively correlated in smokers at baseline.

There is a direct interaction of nicotine with NT3, which is different in acute and chronic exposure. Interestingly, the concentration of NT3 is correlated and up-regulated in smokers. We propose that neuroplasticity, which plays a role in addictive behaviour such as smoking or nicotine dependence (ND) might be mediated by these interactions of nicotine and NT3. We speculate that these might even play a part in the so called “self-medicating” with cigarettes that is often seen in patients with certain mental disorders.

This document is a resource for Emergency Medical Services (EMS) treating an injured law enforcement K9 (LEK9) in the field and/or during transport by ambulance to a veterinary hospital. A Joint Task Force on Working Dog Care was created, which included veterinarians, EMS directors, EMS physicians, and canine handlers, who met to develop a treatment protocol for injured LEK9s. The protocol covers many major life-threatening injuries that LEK9s may sustain in the line of duty, and also discusses personnel safety and necessary equipment. This protocol may help train EMS providers to save the life of an injured LEK9.