Current United States Preventive Services Task Force (USPSTF) recommendations include routine screening for breast, cervical, colorectal, and lung cancer; however, two out of every three cancer cases occur in other indications, leading to diagnoses in advanced stages of the disease and a higher likelihood of mortality. Blood-based multi-cancer early detection (MCED) tests can impact cancer screening and early detection by monitoring for multiple different cancer types at once, including indications where screening is not performed routinely today. We conducted a survey amongst healthcare providers (HCPs), payers, and patients within the U.
View Article and Find Full Text PDFOur theory of positively reinforced free-operant behavior (Perez & Dickinson, 2020) assumes that responding is controlled by two systems. One system is sensitive to the correlation between response and reinforcement rates and controls goal-directed behavior, whereas a habitual system learns by reward prediction error. We present an extension of this theory to the aversive domain that explains why free-operant avoidance responding increases with both the experienced rate of negative reinforcement and the difference between this rate and that programmed by the avoidance schedule.
View Article and Find Full Text PDFThe influence of the Rescorla-Wagner model cannot be overestimated, despite that (1) the model does not differ much computationally from its predecessors and competitors, and (2) its shortcomings are well-known in the learning community. Here we discuss the reasons behind its widespread influence in the cognitive and neural sciences, and argue that it is the constant search for general-process theories by learning scholars which eventually produced a model whose application spans many different areas of research to this day. We focus on the theoretical and empirical background of the model, the theoretical connections that it has with later developments across Marr's levels of analysis, as well as the broad variety of research that it has guided and inspired.
View Article and Find Full Text PDFUnderstanding how culture evolves in society is an extremely difficult task. The bifocal stance theory (BST) deploys two copying strategies which can be linked to dual-system theories of behavior. BST would benefit from incorporating results from these theories, such as the evolution of attention to goals or steps of a behavioral sequence, and the role of the environment in prompting different copying strategies.
View Article and Find Full Text PDFIn the natural world, stimulus-outcome associations are often ambiguous, and most associations are highly complex and situation-dependent. Learning to disambiguate these complex associations to identify which specific outcomes will occur in which situations is critical for survival. Pavlovian occasion setters are stimuli that determine whether other stimuli will result in a specific outcome.
View Article and Find Full Text PDFDespite evidence that precision medicine (PM) results in improved patient care, the broad adoption and implementation has been challenging across the United States (US). To better understand the perceived barriers associated with PM adoption, a quantitative survey was conducted across five stakeholders including medical oncologists, surgeons, lab directors, payers, and patients. The results of the survey reveal that stakeholders are often not aligned on the perceived challenges with PM awareness, education and reimbursement, with there being stark contrast in viewpoints particularly between clinicians, payers, and patients.
View Article and Find Full Text PDFTheories of learning distinguish between elemental and configural stimulus processing depending on whether stimuli are processed independently or as whole configurations. Evidence for elemental processing comes from findings of summation in animals where a compound of two dissimilar stimuli is deemed to be more predictive than each stimulus alone, whereas configural processing is supported by experiments using similar stimuli in which summation is not found. However, in humans the summation effect is robust and impervious to similarity manipulations.
View Article and Find Full Text PDFIt has been suggested that there are two distinct and parallel mechanisms for controlling instrumental behavior in mammals: goal-directed actions and habits. To gain an understanding of how these two systems interact to control behavior, it is essential to characterize the mechanisms by which the balance between these systems is influenced by experience. Studies in rodents have shown that the amount of training governs the relative expression of these two systems: Behavior is goal-directed following moderate training, but the more extensively an instrumental action is trained, the more it becomes habitual.
View Article and Find Full Text PDFData on transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), among college athletes are limited. In August 2020, the Chicago Department of Public Health (CDPH) was notified of a cluster of COVID-19 cases among a university's men's and women's soccer teams. CDPH initiated an investigation, interviewed members of both teams, and collated laboratory data to understand transmission of SARS-CoV-2 within the teams.
View Article and Find Full Text PDFSince December 2019, SARS-CoV-2 has spread extensively throughout the world, with more than 117 million reported cases and 2.6 million deaths (Johns Hopkins coronavirus resource center, https://coronavirus.jhu.
View Article and Find Full Text PDFCeftazidime/avibactam is an important treatment option for infections caused by carbapenemase-producing (KPC-Kp), however, resistance can emerge during treatment. The objective of the study was to define the ceftazidime/avibactam concentrations required to suppress bacterial regrowth in ceftazidime/avibactam susceptible isolates and identify active therapies against ceftazidime/avibactam-resistant KPC-Kp. Time-kill assays were performed against twelve ST258 KPC-Kp isolates that harbored or .
View Article and Find Full Text PDFBackground: People experiencing homelessness are at increased risk of coronavirus disease 2019 (COVID-19), but little is known about specific risk factors for infection within homeless shelters.
Methods: We performed widespread severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) polymerase chain reaction testing and collected risk factor information at all homeless shelters in Chicago with at least 1 reported case of COVID-19 (n = 21). Multivariable, mixed-effects log-binomial models were built to estimate adjusted prevalence ratios (aPRs) for SARS-CoV-2 infection for both individual- and facility-level risk factors.
Recent theories of instrumental behavior postulate that the correlation between response and reward rate is a critical factor in instrumental goal-directed performance. However, it is still not clear whether human actions can be sensitive to rate correlation. Using a novel within-subject design, participants were trained under ratio and interval contingencies of reinforcement matching both reward probabilities and reward rates between conditions.
View Article and Find Full Text PDFContemporary theories of instrumental performance assume that responding can be controlled by 2 behavioral systems, 1 goal-directed that encodes the outcome of an action, and 1 habitual that reinforces the response strength of the same action. Here we present a model of free-operant behavior in which goal-directed control is determined by the correlation between the rates of the action and the outcome whereas the total prediction error generated by contiguous reinforcement by the outcome controls habitual response strength. The outputs of these two systems summate to generate a total response strength.
View Article and Find Full Text PDFQ J Exp Psychol (Hove)
April 2020
Human experiments have demonstrated that instrumental performance of an action and the causal beliefs of the effectiveness of an action in producing a reward are correlated and controlled by the probability of an action leading to a reward. The animal literature, however, shows that instrumental performance under free-operant training differs even when the reward probabilities are matched while subjects undergo training under ratio or interval schedules of reward. In two experiments, we investigated whether causal beliefs would correlate with instrumental performance under ratio and interval schedules for matched reward probabilities.
View Article and Find Full Text PDFHepatitis C virus (HCV) and human immunodeficiency virus (HIV) co-infection among persons who inject drugs (PWID) is a major public health concern. There are limited data in clinical trials on the use of direct-acting antiviral (DAA) therapy for treatment of HCV in co-infected PWID. It is critical for these patients to gain access to treatment in order to decrease progression of liver disease and decrease transmission of both HIV and HCV.
View Article and Find Full Text PDFIntroduction: Endorphins, endocannabinoids, monoamines, and neurotrophins have all been implicated in the euphoric response to endurance running, known as a runner's high (RH). The epitranscriptional mechanisms regulating this effect have not been defined. Here, we investigate peripheral micro-ribonucleic acid (miRNA) changes unique to athletes experiencing postrun euphoria, yielding insights into gene networks that control an RH.
View Article and Find Full Text PDFThe higher response rates observed on ratio than on matched interval reward schedules has been attributed to the differential reinforcement of longer inter-response times (IRTs) on the interval contingency. Some data, however, seem to contradict this hypothesis, showing that the difference is still observed when the role of IRT reinforcement is neutralized by using a regulated-probability interval schedule (RPI). Given the mixed evidence for these predictions, we re-examined this hypothesis by training three groups of rats to lever press under ratio, interval and RPI schedules across two phases while matching reward rates within triads.
View Article and Find Full Text PDFSeveral contemporary models anticipate that the summation effect is modulated by the similarity between the cues forming a compound. Here, we explore this hypothesis in a series of causal learning experiments. Participants were presented with two visual cues that separately predicted a common outcome and later asked for the outcome predicted by the compound of the two cues.
View Article and Find Full Text PDFMicroribonucleic acids (miRNAs) mediate adaptive responses to exercise and may serve as biomarkers of exercise intensity/capacity. Expression of miRNAs is altered in skeletal muscle, plasma, and saliva following exertion. Women display unique physiologic responses to endurance exercise, and miRNAs respond to pathologic states in sex-specific patterns.
View Article and Find Full Text PDFZika virus (ZIKV) is a mosquito-borne flavivirus that has recently been responsible for a serious outbreak of disease in South and Central America. Infection with ZIKV has been associated with severe neurological symptoms and the development of microcephaly in unborn fetuses. Many of the regions involved in the current outbreak are known to be endemic for another flavivirus, dengue virus (DENV), which indicates that a large percentage of the population may have pre-existing DENV immunity.
View Article and Find Full Text PDFALK, ROS1 and RET gene fusions are important predictive biomarkers for tyrosine kinase inhibitors in lung cancer. Currently, the gold standard method for gene fusion detection is Fluorescence In Situ Hybridization (FISH) and while highly sensitive and specific, it is also labour intensive, subjective in analysis, and unable to screen a large numbers of gene fusions. Recent developments in high-throughput transcriptome-based methods may provide a suitable alternative to FISH as they are compatible with multiplexing and diagnostic workflows.
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