The great divide: rhamnolipids mediate separation between P. aeruginosa and S. aureus.

The interactions between bacterial species during infection can have significant impacts on pathogenesis. Pseudomonas aeruginosa and Staphylococcus aureus are opportunistic bacterial pathogens that can co-infect hosts and cause serious illness. The factors that dictate whether one species outcompetes the other or whether the two species coexist are not fully understood. We investigated the role of surfactants in the interactions between these two species on a surface that enables P. aeruginosa to swarm. We found that P. aeruginosa swarms are repelled by colonies of clinical S. aureus isolates, creating physical separation between the two strains. This effect was abolished in mutants of S. aureus that were defective in the production of phenol-soluble modulins (PSMs), which form amyloid fibrils around wild-type S. aureus colonies. We investigated the mechanism that establishes physical separation between the two species using Imaging of Reflected Illuminated Structures (IRIS), which is a non-invasive imaging method that tracks the flow of surfactants produced by P. aeruginosa. We found that PSMs produced by S. aureus deflected the surfactant flow, which in turn, altered the direction of P. aeruginosa swarms. These findings show that rhamnolipids mediate physical separation between P. aeruginosa and S. aureus, which could facilitate coexistence between these species. Additionally, we found that a number of molecules repelled P. aeruginosa swarms, consistent with a surfactant deflection mechanism. These include Bacillus subtilis surfactant, the fatty acids oleic acid and linoleic acid, and the synthetic lubricant polydimethylsiloxane. Lung surfactant repelled P. aeruginosa swarms and inhibited swarm expansion altogether at higher concentration. Our results suggest that surfactant interactions could have major impacts on bacteria-bacteria and bacteria-host relationships. In addition, our findings uncover a mechanism responsible for P. aeruginosa swarm development that does not rely solely on sensing but instead is based on the flow of surfactant.

On the murky dissociation between expression and communication.

The authors present an ambitious attempt to outline the gradual evolution of the cognitive foundations of ostensive communication. We focus on three problematic aspects of the distinction between expression and communication: ambiguity in the distinction's central principle of "complementary mechanisms," inconsistencies in the application of the distinction across taxa, and the dismissal of mentalizing in nonhuman primates.

Staphylococcal secreted cytotoxins are competition sensing signals for Pseudomonas aeruginosa.

Coinfection with two notorious opportunistic pathogens, the Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus , dominates chronic pulmonary infections. While coinfection is associated with poor patient outcomes, the interspecies interactions responsible for such decline remain unknown. Here, we dissected molecular mechanisms of interspecies sensing between P. aeruginosa and S. aureus . We discovered that P. aeruginosa senses S. aureus secreted peptides and, counterintuitively, moves towards these toxins. P. aeruginosa tolerates such a strategy through "competition sensing", whereby it preempts imminent danger/competition by arming cells with type six secretion (T6S) and iron acquisition systems. Intriguingly, while T6S is predominantly described as weaponry targeting Gram-negative and eukaryotic cells, we find that T6S is essential for full P. aeruginosa competition with S. aureus , a previously undescribed role for T6S. Importantly, competition sensing was activated during coinfection of bronchial epithelia, including T6S islands targeting human cells. This study reveals critical insight into both interspecies competition and how antagonism may cause collateral damage to the host environment.

Primate cognition in zoos: Reviewing the impact of zoo-based research over 15 years.

Primate cognition research is reliant on access to members of the study sp ecies and logistical infrastructures to conduct observations and experiments. Historically founded in research centers and private collections, and spreading to modern zoos, sanctuaries, and the field, primate cognition has been investigated in diverse settings, each with benefits and challenges. In our systematic review of 12 primatology, animal behavior, and animal cognition journals over the last 15 years, we turn a spotlight on zoos to quantify their current impact on the field and to highlight their potential as robust contributors to future work. To put zoo-based research in context, we compare zoos to three other site types: university-owned or independent research centers, sanctuaries, and field sites. We assess the contributions of zoos across several critical considerations in primate cognition research, including number of investigations, species diversity, sample size, research topic diversity, and methodology. We identified 1119 publications reporting studies of primate cognition, almost 25% of which report research conducted in zoos. Across publications, zoo-based research has greater species diversity than research centers and covers a diverse range of research topics. Although our review is merely a snapshot of primate cognition research, our findings suggest that zoos may present advantages to researchers regarding species diversity, and lack some of the methodological constraints of field sites, allowing greater ease of access to a diverse range of subjects for cognition investigations. We suggest that zoos have great potential as key contributors for future investigations in primate cognition. Finally, we shed light on the symbiotic relationship that can emerge between researchers and zoos, forming partnerships that bring unique advantages to both parties.

Promoting Cardiac Rehabilitation in Acute Coronary Syndrome Patients: Quality Initiative Based on Education, Automated Referral, and Multidisciplinary Rounds.

Cardiac rehabilitation is a class 1 recommendation for acute coronary syndrome (ACS) patients according to the American College of Cardiology/American Heart Association. However, only 1 in 5 ACS patients are referred for cardiac rehabilitation nationally, and even fewer at our institution. We sought to improve the number of referrals to cardiac rehabilitation for post-ACS patients admitted to our inpatient cardiology service, and ultimately their participation in the program. We designed a quality improvement initiative that included education of patients and house staff, automated referral order, and participation of cardiac rehabilitation staff members on multidisciplinary rounds. We compared the number of patients who received a referral to cardiac rehabilitation, had the first appointment scheduled before hospital discharge, and attended the program before and after our intervention. Six months after initiation of the project, the proportion of ACS patients referred to cardiac rehabilitation before hospital discharge increased from 10% to 43% (P < 0.001). The mean number of patients with a cardiac rehabilitation appointment scheduled before discharge was 2 before and 5 after the intervention (P < 0.001), and the mean number of patients who attended their scheduled appointment was 1 before and 3 after the intervention (P = 0.001). Run charts demonstrated that the number of referrals and the number of scheduled appointments remained above the median following the intervention. In conclusion, an initiative that included education, automated referrals, and direct one-on-one contact with cardiac rehabilitation staff before discharge increased the number of cardiac rehabilitation referrals, and appointments scheduled and attended in post-ACS patients.

Inferential Communication: Bridging the Gap Between Intentional and Ostensive Communication in Non-human Primates.

Communication, when defined as an act intended to affect the psychological state of another individual, demands the use of inference. Either the signaler, the recipient, or both must make leaps of understanding which surpass the semantic information available and draw from pragmatic clues to fully imbue and interpret meaning. While research into human communication and the evolution of language has long been comfortable with mentalistic interpretations of communicative exchanges, including rich attributions of mental state, research into animal communication has balked at theoretical models which describe mentalized cognitive mechanisms. We submit a new theoretical perspective on animal communication: the model of inferential communication. For use when existing proximate models of animal communication are not sufficient to fully explain the complex, flexible, and intentional communication documented in certain species, specifically non-human primates, we present our model as a bridge between shallower, less cognitive descriptions of communicative behavior and the perhaps otherwise inaccessible mentalistic interpretations of communication found in theoretical considerations of human language. Inferential communication is a framework that builds on existing evidence of referentiality, intentionality, and social inference in primates. It allows that they might be capable of applying social inferences to a communicative setting, which could explain some of the cognitive processes that enable the complexity and flexibility of primate communication systems. While historical models of animal communication focus on the means-ends process of behavior and apparent cognitive outcomes, inferential communication invites consideration of the mentalistic processes that must underlie those outcomes. We propose a mentalized approach to questions, investigations, and interpretations of non-human primate communication. We include an overview of both ultimate and proximate models of animal communication, which contextualize the role and utility of our inferential communication model, and provide a detailed breakdown of the possible levels of cognitive complexity which could be investigated using this framework. Finally, we present some possible applications of inferential communication in the field of non-human primate communication and highlight the role it could play in advancing progress toward an increasingly precise understanding of the cognitive capabilities of our closest living relatives.

Effect of Medication Adherence and Early Follow-Up on Unplanned Readmission Post-Myocardial Infarction: Quality Improvement in a Safety Net Hospital.

Medication nonadherence is a strong predictor of adverse events and unplanned 30-day readmissions in post-myocardial infarction (MI) patients. Nonadherence with dual antiplatelet therapy (DAPT) is of particular concern in post-MI patients, given the high rate of percutaneous coronary intervention in this population. Review of post-MI quality measures revealed that compared to national benchmarks, our safety net hospital had lower DAPT adherence rates and higher unplanned 30-day readmission rates. The aim was to improve these important quality measures by creating a transition of care pathway primarily focused on medication accessibility and affordability of DAPT and early follow-up. A multidisciplinary task force created a transition of care pathway that included bedside medication delivery, patient assistance program enrollment for medications, and follow-up within 10 days of discharge in a dedicated post-MI clinic. Resources for the pathway (personnel and hospital) were already available and repurposed. We compared quality measures of DAPT adherence, proportion of patients evaluated early after hospital discharge, and unplanned 30-day readmissions before and after the initiative. Following initiation of the transition of care pathway, DAPT adherence increased from 56% pre-intervention to 92% post-intervention (P < 0.0001). The proportion of patients scheduled for early clinic follow-up after discharge increased and unplanned 30-day readmissions decreased following initiation of the pathway. A transition of care pathway for post-MI patients using readily available resources was associated with increased DAPT adherence and decreased 30-day unplanned readmissions.

Interspecies interactions induce exploratory motility in Pseudomonas aeruginosa.

Microbes often live in multispecies communities where interactions among community members impact both the individual constituents and the surrounding environment. Here, we developed a system to visualize interspecies behaviors at initial encounters. By imaging two prevalent pathogens known to be coisolated from chronic illnesses, Pseudomonas aeruginosa and Staphylococcus aureus, we observed P. aeruginosa can modify surface motility in response to secreted factors from S. aureus. Upon sensing S. aureus, P. aeruginosa transitioned from collective to single-cell motility with an associated increase in speed and directedness - a behavior we refer to as 'exploratory motility'. Explorer cells moved preferentially towards S. aureus and invaded S. aureus colonies through the action of the type IV pili. These studies reveal previously undescribed motility behaviors and lend insight into how P. aeruginosa senses and responds to other species. Identifying strategies to harness these interactions may open avenues for new antimicrobial strategies.

Establishing an infrastructure for collaboration in primate cognition research.

Inferring the evolutionary history of cognitive abilities requires large and diverse samples. However, such samples are often beyond the reach of individual researchers or institutions, and studies are often limited to small numbers of species. Consequently, methodological and site-specific-differences across studies can limit comparisons between species. Here we introduce the ManyPrimates project, which addresses these challenges by providing a large-scale collaborative framework for comparative studies in primate cognition. To demonstrate the viability of the project we conducted a case study of short-term memory. In this initial study, we were able to include 176 individuals from 12 primate species housed at 11 sites across Africa, Asia, North America and Europe. All subjects were tested in a delayed-response task using consistent methodology across sites. Individuals could access food rewards by remembering the position of the hidden reward after a 0, 15, or 30-second delay. Overall, individuals performed better with shorter delays, as predicted by previous studies. Phylogenetic analysis revealed a strong phylogenetic signal for short-term memory. Although, with only 12 species, the validity of this analysis is limited, our initial results demonstrate the feasibility of a large, collaborative open-science project. We present the ManyPrimates project as an exciting opportunity to address open questions in primate cognition and behaviour with large, diverse datasets.

Increased cerebral blood volume and oxygen consumption in neonatal brain injury.

With the increasing interest in treatments for neonatal brain injury, bedside methods for detecting and assessing injury status and evolution are needed. We aimed to determine whether cerebral tissue oxygenation (StO(2)), cerebral blood volume (CBV), and estimates of relative cerebral oxygen consumption (rCMRO(2)) determined by bedside frequency-domain near-infrared spectroscopy (FD-NIRS) have the potential to distinguish neonates with brain injury from those with non-brain issues and healthy controls. We recruited 43 neonates < or =15 days old and >33 weeks gestational age (GA): 14 with imaging evidence of brain injury, 29 without suspicion of brain injury (4 unstable, 6 stable, and 19 healthy). A multivariate analysis of variance with Newman-Keuls post hoc comparisons confirmed group similarity for GA and age at measurement. StO(2) was significantly higher in brain injured compared with unstable neonates, but not statistically different from stable or healthy neonates. Brain-injured neonates were distinguished from all others by significant increases in CBV and rCMRO(2). In conclusion, although NIRS measures of StO(2) alone may be insensitive to evolving brain injury, increased CBV and rCMRO(2) seem to be useful for detecting neonatal brain injury and suggest increased neuronal activity and metabolism occurs acutely in evolving brain injury.

Medical bankruptcy in the United States, 2007: results of a national study.

BACKGROUND: Our 2001 study in 5 states found that medical problems contributed to at least 46.2% of all bankruptcies. Since then, health costs and the numbers of un- and underinsured have increased, and bankruptcy laws have tightened. METHODS: We surveyed a random national sample of 2314 bankruptcy filers in 2007, abstracted their court records, and interviewed 1032 of them. We designated bankruptcies as "medical" based on debtors' stated reasons for filing, income loss due to illness, and the magnitude of their medical debts. RESULTS: Using a conservative definition, 62.1% of all bankruptcies in 2007 were medical; 92% of these medical debtors had medical debts over $5000, or 10% of pretax family income. The rest met criteria for medical bankruptcy because they had lost significant income due to illness or mortgaged a home to pay medical bills. Most medical debtors were well educated, owned homes, and had middle-class occupations. Three quarters had health insurance. Using identical definitions in 2001 and 2007, the share of bankruptcies attributable to medical problems rose by 49.6%. In logistic regression analysis controlling for demographic factors, the odds that a bankruptcy had a medical cause was 2.38-fold higher in 2007 than in 2001. CONCLUSIONS: Illness and medical bills contribute to a large and increasing share of US bankruptcies.

Discounting the debtors will not make medical bankruptcy disappear.

David Dranove and Michael Millenson seem determined to deny that financial fallout from illness pushes middle-class families into bankruptcy. Anxious to erase the headline that three-quarters of U.S. medical bankrupts had health insurance at the onset of their illnesses and the resulting spotlight on inadequate coverage and insurance cancellation practices, they ignore most of our data and misrepresent the rest. They dismiss families' explanations of their difficulties and blame those ruined by illness for their own problems. However, the data from the bankruptcy courts are undeniable. Bankruptcies affect mainly middle-class, privately insured families, and about half are triggered, at least in part, by illnesses.

Illness and injury as contributors to bankruptcy.

In 2001, 1.458 million American families filed for bankruptcy. To investigate medical contributors to bankruptcy, we surveyed 1,771 personal bankruptcy filers in five federal courts and subsequently completed in-depth interviews with 931 of them. About half cited medical causes, which indicates that 1.9-2.2 million Americans (filers plus dependents) experienced medical bankruptcy. Among those whose illnesses led to bankruptcy, out-of-pocket costs averaged dollar 11,854 since the start of illness; 75.7 percent had insurance at the onset of illness. Medical debtors were 42 percent more likely than other debtors to experience lapses in coverage. Even middle-class insured families often fall prey to financial catastrophe when sick.