A computational model of behavioral adaptation to solve the credit assignment problem

The adaptive fitness of an organism in its ecological niche is highly reliant upon its ability to associate an environmental or internal stimulus with a behavior response through reinforcement. This simple but powerful observation has been successfully applied in a number of contexts within computational neuroscience and reinforcement learning to model both human and animal behaviors. However, a critical challenge faced by these models is the credit assignment problem which asks how past behavior comes to be associated with a delayed reinforcement signal. In this paper we reformulate the credit assignment problem to ask how past stimuli come to be linked to adaptive behavioral responses in the context of a simple neuronal circuit. We propose a biologically plausible variant of a spiking neural network which can model a wide variety of behavioral, learning, and evolutionary phenomena. Our model suggests one fundamental mechanism, potentially in use in the brains of both simple and complex organisms, that would allow it to associate a behavior with an adaptive response. We present results that showcase the model's versatility and biological plausibility in a number of tasks related to classical and operant conditioning including behavioral chaining. We then provide further simulations to demonstrate how adaptive behaviors such as reflexes and simple category detection may have evolved using our model. Our results indicate the potential for further modifications and extensions of our model to replicate more sophisticated and biologically plausible behavioral, learning, and intelligence phenomena found throughout the animal kingdom.Comment: 18 pages, 9 figure

Deaf STEM Community Alliance: Establishing a model virtual academic community

Abstract - This presentation describes the incremental and iterative development of the Deaf STEM Community Alliance’s virtual academic community, the Deaf and Hard of Hearing Virtual Academic Community (DHHVAC). The DHHVAC components address three critical barriers to the success of students who are deaf or hard-of-hearing: student preparation, socialization, and access to media

Transcriptome Analyses of Tumor-Adjacent Somatic Tissues Reveal Genes Co-Expressed with Transposable Elements

Background: Despite the long-held assumption that transposons are normally only expressed in the germ-line, recent evidence shows that transcripts of transposable element (TE) sequences are frequently found in the somatic cells. However, the extent of variation in TE transcript levels across different tissues and different individuals are unknown, and the co-expression between TEs and host gene mRNAs have not been examined. Results: Here we report the variation in TE derived transcript levels across tissues and between individuals observed in the non-tumorous tissues collected for The Cancer Genome Atlas. We found core TE co-expression modules consisting mainly of transposons, showing correlated expression across broad classes of TEs. Despite this co-expression within tissues, there are individual TE loci that exhibit tissue-specific expression patterns, when compared across tissues. The core TE modules were negatively correlated with other gene modules that consisted of immune response genes in interferon signaling. KRAB Zinc Finger Proteins (KZFPs) were over-represented gene members of the TE modules, showing positive correlation across multiple tissues. But we did not find overlap between TE-KZFP pairs that are co-expressed and TE-KZFP pairs that are bound in published ChIP-seq studies. Conclusions: We find unexpected variation in TE derived transcripts, within and across non-tumorous tissues. We describe a broad view of the RNA state for non-tumorous tissues exhibiting higher level of TE transcripts. Tissues with higher level of TE transcripts have a broad range of TEs co-expressed, with high expression of a large number of KZFPs, and lower RNA levels of immune genes

Correction to: Transcriptome Analyses of Tumor-Adjacent Somatic Tissues Reveal Genes Co-Expressed with Transposable Elements

Following publication of the original article [1], the authors reported errors in Table 2 wherein all “KZFP” in the gene names should be changed to “ZNF”

Development of paediatric non-stage prognosticator guidelines for population-based cancer registries and updates to the 2014 Toronto Paediatric Cancer Stage Guidelines

Population-based cancer registries (PBCRs) generate measures of cancer incidence and survival that are essential for cancer surveillance, research, and cancer control strategies. In 2014, the Toronto Paediatric Cancer Stage Guidelines were developed to standardise how PBCRs collect data on the stage at diagnosis for childhood cancer cases. These guidelines have been implemented in multiple jurisdictions worldwide to facilitate international comparative studies of incidence and outcome. Robust stratification by risk also requires data on key non-stage prognosticators (NSPs). Key experts and stakeholders used a modified Delphi approach to establish principles guiding paediatric cancer NSP data collection. With the use of these principles, recommendations were made on which NSPs should be collected for the major malignancies in children. The 2014 Toronto Stage Guidelines were also reviewed and updated where necessary. Wide adoption of the resultant Paediatric NSP Guidelines and updated Toronto Stage Guidelines will enhance the harmonisation and use of childhood cancer data provided by PBCRs

Recommendation to Reduce Patients’ Blood Pressure and Cholesterol Medication Costs

The Community Preventive Services Task Force recommends reducing patient out-of-pocket costs (ROPC) for medications to control high blood pressure and high cholesterol when combined with additional interventions aimed at improving patient–provider interaction and patient knowledge, such as team-based care with medication counseling, and patient education

Treatment of hemangiomas in children using a Nd:YAG laser in conjunction with ice cooling of the epidermis: techniques and results

BACKGROUND: Hemangiomas are the most common type of congenital anomaly in childhood. Although many resolve spontaneously, intervention is required when their growth could damage vital adjacent structures. Various therapeutic approaches to childhood hemangiomas with different types of laser have been described previously. The objective of this study was to determine whether the cooling of the epidermis during irradiation of hemangiomas with a Nd:YAG laser prevents thermal damage and decreases the number of sessions required to treat these lesions. METHODS: Between 1993 and 2001, 110 patients aged 3 months to 4 years, with cutaneous hemangiomas were treated with a Nd:YAG laser. The lesion was cooled with ice prior to, during, and after the irradiation. During each session the laser beam passed through the pieces of ice. The laser power was between 35–45 W with a pulse length of 2–10 seconds. RESULTS: After 6 months of follow-up, from the first session of laser treatment, total resolution was obtained in 72 (65.5%) patients. A second or third session followed in 30 out of 38 patients in which, the initial results were good, moderate, or poor. The parents of the remaining eight children refused this second session and these patients excluded from the study Complications were seen in nine (8.8%) patients. One patient had postoperative bleeding which stopped spontaneously, while atrophic scars occurred in six (5.8%) patients, and hypertrophic scars in two (1.9%) patients. CONCLUSIONS: Nd:YAG laser irradiation in conjunction with ice protection of the epidermis produces good cosmetic results for the treatment of cutaneous hemangiomas in children, and decreases the number of sessions for treatment of these lesions