Behaviour and the Origin of Organisms.

It is common in origins of life research to view the first stages of life as the passive result of particular environmental conditions. This paper considers the alternative possibility: that the antecedents of life were already actively regulating their environment to maintain the conditions necessary for their own persistence. In support of this proposal, we describe 'viability-based behaviour': a way that simple entities can adaptively regulate their environment in response to their health, and in so doing, increase the likelihood of their survival. Drawing on empirical investigations of simple self-preserving abiological systems, we argue that these viability-based behaviours are simple enough to precede neo-Darwinian evolution. We also explain how their operation can reduce the demanding requirements that mainstream theories place upon the environment(s) in which life emerged.

Going big by going small: Trade-offs in microbiome explanations of cancer.

Microbial factors have been implicated in cancer risk, disease progression, treatment and prevention. The key word, however, is "implicated." Our aim in this paper is to map out some of the tensions between competing methods, goals, and standards of evidence in cancer research with respect to the causal role of microbial factors. We discuss an array of pragmatic and epistemic trade-offs in this research area: prioritizing coarse-grained versus fine-grained explanations of the roles of microbiota in cancer; explaining general versus specific cancer targets; studying model organisms versus human patients; and understanding and explaining cancer versus developing diagnostic tools and treatments. In light of these trade-offs and the distinctive complexity and heterogeneity on both sides of the microbiome-cancer relationship, we suggest that it would be more productive and intellectually honest to frame much of this work, at least currently, in terms of generating causal hypotheses to investigate further. Claims of established causal connections between the microbiome and cancer are in many cases overstated. We also discuss the value of "black boxing" microbial causal variables in this research context and draw some general cautionary lessons for ongoing discussions of microbiomes and cancer.

Exploring political diversity in relation to health and stress, among graduate students in the mental health field.

ObjectiveExamine associations between political diversity, health, and stress in a student sample for whom examining political biases is necessary. Participants: Graduate students in mental health (N = 512) from July 2017 to June 2018. Methods: Participants completed an online survey of political views, health, and stress. Descriptive statistics reported sample characteristics; stepwise regressions tested whether political affiliation and perceived political majority/minority status predicted health and stress. Results: Students identified primarily as liberal, and perceived their counterparts as liberal. Liberal political identification generally predicted more stress and poorer health in several domains; however, those identifying as most politically conservative also reported relatively high stress. Conclusions: Liberal academic environments may relate to stress for those who identify as most politically conservative, while also not protecting liberals against broader sociopolitical stress and related health sequelae. Graduate students in mental health may benefit from increased curricular and supervisory focus on political diversity and related biases.

Microbes, mathematics, and models.

Microbial model systems have a long history of fruitful use in fields that include evolution and ecology. In order to develop further insight into modelling practice, we examine how the competitive exclusion and coexistence of competing species have been modelled mathematically and materially over the course of a long research history. In particular, we investigate how microbial models of these dynamics interact with mathematical or computational models of the same phenomena. Our cases illuminate the ways in which microbial systems and equations work as models, and what happens when they generate inconsistent findings about shared targets. We reveal an iterative strategy of comparative modelling in different media, and suggest reasons why microbial models have a special degree of epistemic tractability in multimodel inquiry.

Evaluation of dexmedetomidine and postoperative pain management in patients with adolescent idiopathic scoliosis: conclusions based on a retrospective study at a tertiary pediatric hospital.

OBJECTIVES: This study evaluated the effectiveness of dexmedetomidine in decreasing opioid use in children with adolescent idiopathic scoliosis following posterior spinal fusion surgery at a pediatric tertiary care hospital over the past 10 years. DESIGN: This was a retrospective chart review. Patients were separated into two groups: those that received opioid via patient-controlled analgesia pain therapy alone and those that received opioid via patient-controlled analgesia pain therapy with dexmedetomidine. SETTING: A tertiary pediatric free-standing hospital. The study focused on care administered in the perioperative period, including the operating room, ICU, and general hospital floor. PATIENTS: One hundred sixty-three children with adolescent idiopathic scoliosis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Measurements included patient demographics, American Society of Anesthesiologists Physical Status Classification System, levels of spinal fusion, length of hospital stay, complications, numeric pain scores, opioid requirement, elastomeric pain pump use, length of time until ambulation, adverse effects, and naloxone use. Data were collected through the first 72 hours of the perioperative period. One hundred six patients received opioids via patient-controlled analgesia therapy with dexmedetomidine and 57 received opioids via patient-controlled analgesia alone. Within the groups, there were 46 patients who received local anesthetic infusions via elastomeric pumps in the patient-controlled analgesia with dexmedetomidine group and 16 patients had pumps in the patient-controlled analgesia-alone group. There was no overall difference in postoperative use of morphine (or equivalents) between the two groups. However, the use of elastomeric pain pumps demonstrated a statistically significant decrease in mean overall opioid consumption (42.6 mg vs 63.1 mg, p < 0.001). CONCLUSIONS: There was no difference in opioid use related to dexmedetomidine on any postoperative day. The only variable showing a significant opioid sparing effect was the use of local anesthetic infusions via elastomeric pumps. Using continuous local anesthetic infusions instead of dexmedetomidine could eliminate the need for ICU admission, require shorter hospital stays, and reduce costs while still providing safe and effective pain control.

Flies from meat and wasps from trees: Reevaluating Francesco Redi's spontaneous generation experiments.

Francesco Redi's seventeenth-century experiments on insect generation are regarded as a key contribution to the downfall of belief in spontaneous generation. Scholars praise Redi for his experiments demonstrating that meat does not generate insects, but condemn him for his claim elsewhere that trees can generate wasps and gallflies. He has been charged with rejecting spontaneous generation only to change his mind and accept it, and in the process, with failing (at least in some sense) as a rigorous experimental philosopher. In this paper I defend Redi from both of these charges. In doing so, I draw some broader lessons for our understanding of spontaneous generation. 'Spontaneous generation' does not refer to a single theory, but rather a landscape of possible views. I analyze Redi's theoretical commitments and situate them within this landscape, and argue that his error in the case of insects from plants is not as problematic as previous commentators have said it is. In his research on gall insects Redi was addressing a different question from that of his experiments on insect generation-the question was not "Can insects come from nonliving matter?," but rather, "Can insects come from living organisms which are not their parents (namely, trees)?" In the latter case, he gave an answer which we now know to be false, but this was not due to any failure in his rigor as an experimental philosopher.

Social and ethical checkpoints for bottom-up synthetic biology, or protocells.

An alternative to creating novel organisms through the traditional "top-down" approach to synthetic biology involves creating them from the "bottom up" by assembling them from non-living components; the products of this approach are called "protocells." In this paper we describe how bottom-up and top-down synthetic biology differ, review the current state of protocell research and development, and examine the unique ethical, social, and regulatory issues raised by bottom-up synthetic biology. Protocells have not yet been developed, but many expect this to happen within the next five to ten years. Accordingly, we identify six key checkpoints in protocell development at which particular attention should be given to specific ethical, social and regulatory issues concerning bottom-up synthetic biology, and make ten recommendations for responsible protocell science that are tied to the achievement of these checkpoints.

Patient-controlled epidural analgesia (PCEA) for postoperative pain control after lumbar spine surgery.

Spine surgery remains one of the most common procedures for patients with a wide variety of spine disorders. Postoperative pain after major spine surgery is moderate to severe. We retrospectively reviewed 245 medical records of adult patients undergoing major spine surgery who received either patient-controlled epidural analgesia based on local anesthetics and opioids or patient-controlled intravenous analgesia as postoperative pain management. Several outcomes were analyzed including pain intensity, opioid consumption, time to endotracheal extubation, the incidence of deep venous thrombosis, and length of stay in the hospital. We found that the use of patient-controlled epidural analgesia provided better postoperative analgesia [median (quartiles) verbal analog scale score of 4 (3, 5) vs. 5 (3, 6)] and decreased the amount of opioid consumption postoperatively [median of 0 mg (0, 3) vs. 35 mg (0, 150)] compared with patient-controlled intravenous analgesia. Also, a substantially higher number of patients in the patient-controlled intravenous group required opioids as rescue analgesia. Incidences of deep venous thrombosis, operating room extubation, and length of stay in the hospital were not associated with the analgesic technique. The results of this study suggest that the use of neuroaxial analgesia for the management of postoperative pain associated with major spine surgery may have some beneficial properties over intravenous analgesia. The use of a reduced amount of opioids by patients with epidural analgesia may be relevant because of potential fewer side effects mainly in elderly patients. Several limitations related to the retrospective nature of the study are described. Prospective randomized-controlled trials are needed to understand and elucidate the optimum regimen of postoperative pain management after major spine surgery.