Category-specific memory encoding in the medial temporal lobe and beyond: the role of reward.

The medial temporal lobe (MTL), including the hippocampus (HC), perirhinal cortex (PRC), and parahippocampal cortex (PHC), is central to memory formation. Reward enhances memory through interplay between the HC and substantia nigra/ventral tegmental area (SNVTA). While the SNVTA also innervates the MTL cortex and amygdala (AMY), their role in reward-enhanced memory is unclear. Prior research suggests category specificity in the MTL cortex, with the PRC and PHC processing object and scene memory, respectively. It is unknown, however, whether reward modulates category-specific memory processes. Furthermore, no study has demonstrated clear category specificity in the MTL for encoding processes contributing to subsequent recognition memory. To address these questions, we had 39 healthy volunteers (27 for all memory-based analyses) undergo functional magnetic resonance imaging while performing an incidental encoding task pairing objects or scenes with high or low reward, followed by a next-day recognition test. Behaviorally, high reward preferably enhanced object memory. Neural activity in the PRC and PHC reflected successful encoding of objects and scenes, respectively. Importantly, AMY encoding effects were selective for high-reward objects, with a similar pattern in the PRC. The SNVTA and HC showed no clear evidence of successful encoding. This behavioral and neural asymmetry may be conveyed through an anterior-temporal memory system, including the AMY and PRC, potentially in interplay with the ventromedial prefrontal cortex.

CardioNet: a manually curated database for artificial intelligence-based research on cardiovascular diseases.

BACKGROUND: Cardiovascular diseases (CVDs) are difficult to diagnose early and have risk factors that are easy to overlook. Early prediction and personalization of treatment through the use of artificial intelligence (AI) may help clinicians and patients manage CVDs more effectively. However, to apply AI approaches to CVDs data, it is necessary to establish and curate a specialized database based on electronic health records (EHRs) and include pre-processed unstructured data. METHODS: To build a suitable database (CardioNet) for CVDs that can utilize AI technology, contributing to the overall care of patients with CVDs. First, we collected the anonymized records of 748,474 patients who had visited the Asan Medical Center (AMC) or Ulsan University Hospital (UUH) because of CVDs. Second, we set clinically plausible criteria to remove errors and duplication. Third, we integrated unstructured data such as readings of medical examinations with structured data sourced from EHRs to create the CardioNet. We subsequently performed natural language processing to structuralize the significant variables associated with CVDs because most results of the principal CVD-related medical examinations are free-text readings. Additionally, to ensure interoperability for convergent multi-center research, we standardized the data using several codes that correspond to the common data model. Finally, we created the descriptive table (i.e., dictionary of the CardioNet) to simplify access and utilization of data for clinicians and engineers and continuously validated the data to ensure reliability. RESULTS: CardioNet is a comprehensive database that can serve as a training set for AI models and assist in all aspects of clinical management of CVDs. It comprises information extracted from EHRs and results of readings of CVD-related digital tests. It consists of 27 tables, a code-master table, and a descriptive table. CONCLUSIONS: CardioNet database specialized in CVDs was established, with continuing data collection. We are actively supporting multi-center research, which may require further data processing, depending on the subject of the study. CardioNet will serve as the fundamental database for future CVD-related research projects.

The artoriine wolf spiders of Australia: the new genus Kochosa and a key to genera (Araneae: Lycosidae).

A key to the six Australian genera of the wolf spider (Lycosidae Sundevall, 1833) subfamily Artoriinae Framenau, 2007 is provided, now including Artoria Thorell, 1877, Artoriopsis Framenau, 2007, Diahogna Roewer, 1960, Kangarosa Framenau, 2010, Kochosa gen. nov. and Tetralycosa Roewer, 1960. Kochosa gen. nov. is described to include 16 species: K. australia sp. nov. (type species; from New South Wales, Queensland, South Australia, Victoria, Western Australia), K. aero sp. nov. (Western Australia), K. asterix sp. nov. (New South Wales, Queensland, Tasmania and Victoria), K. confusa sp. nov. (Queensland), K. erratum sp. nov. (Queensland), K. fleurae sp. nov. (Victoria), K. mendum sp. nov. (Australian Capital Territory, New South Wales, Queensland), K. nigra sp. nov. (Queensland), K. obelix sp. nov. (Western Australia), K. queenslandica sp. nov. (Queensland), K. sharae sp. nov. (South Australia), K. tanakai sp. nov. (New South Wales, Queensland), K. tasmaniensis sp. nov. (Tasmania), K. timwintoni sp. nov. (Western Australia), K. tongiorgii sp. nov., (Queensland), and K. westralia sp. nov. (Western Australia). Kochosa gen. nov. differs distinctly from all other genera within the Artoriinae by somatic and genitalic morphology. Most conspicuous is a distinct off-white or yellowish-white cardiac mark on an otherwise generally uniformly dark abdomen. The cardiac mark is rendered by thick black setae, which are particularly dense posteriorly. The tegular apophysis of the male pedipalp is heavily reduced, generally forming a semi-transparent small lobe. In turn, the embolic division is often complex with a variety of apophyses. Kochosa gen. nov. generally inhabit mesic habitats such as temperate and tropical shrubs and forests along the eastern and south-eastern coast and in the south-western parts of Australia.

xECGNet: Fine-tuning attention map within convolutional neural network to improve detection and explainability of concurrent cardiac arrhythmias.

Background and objectiveDetecting abnormal patterns within an electrocardiogram (ECG) is crucial for diagnosing cardiovascular diseases. We start from two unresolved problems in applying deep-learning-based ECG classification models to clinical practice: first, although multiple cardiac arrhythmia (CA) types may co-occur in real life, the majority of previous detection methods have focused on one-to-one relationships between ECG and CA type, and second, it has been difficult to explain how neural-network-based CA classifiers make decisions. We hypothesize that fine-tuning attention maps with regard to all possible combinations of ground-truth (GT) labels will improve both the detection and interpretability of co-occurring CAs. Methods To test our hypothesis, we propose an end-to-end convolutional neural network (CNN), xECGNet, that fine-tunes the attention map to resemble the averaged response maps of GT labels. Fine-tuning is achieved by adding to the objective function a regularization loss between the attention map and the reference (averaged) map. Performance is assessed by F1 score and subset accuracy. Results The main experiment demonstrates that fine-tuning alone significantly improves a model's multilabel subset accuracy from 75.8% to 84.5% when compared with the baseline model. Also, xECGNet shows the highest F1 score of 0.812 and yields a more explainable map that encompasses multiple CA types, when compared to other baseline methods. Conclusions xECGNet has implications in that it tackles the two obstacles for the clinical application of CNN-based CA detection models with a simple solution of adding one additional term to the objective function.

Neural correlates of episodic memory modulated by temporally delayed rewards.

When a stimulus is associated with an external reward, its chance of being consolidated into long-term memory is boosted via dopaminergic facilitation of long-term potentiation in the hippocampus. Given that higher temporal distance (TD) has been found to discount the subjective value of a reward, we hypothesized that memory performance associated with a more immediate reward will result in better memory performance. We tested this hypothesis by measuring both behavioral memory performance and brain activation using functional magnetic resonance imaging (fMRI) during memory encoding and retrieval tasks. Contrary to our hypothesis, both behavioral and fMRI results suggest that the TD of rewards might enhance the chance of the associated stimulus being remembered. The fMRI data demonstrate that the lateral prefrontal cortex, which shows encoding-related activation proportional to the TD, is reactivated when searching for regions that show activation proportional to the TD during retrieval. This is not surprising given that this region is not only activated to discriminate between future vs. immediate rewards, it is also a part of the retrieval-success network. These results provide support for the conclusion that the encoding-retrieval overlap provoked as the rewards are more delayed may lead to better memory performance of the items associated with the rewards.

Feulgen reaction study of novel threadlike structures (Bonghan ducts) on the surfaces of mammalian organs.

Threadlike structures on the surfaces of internal organs, which are thought to be part of the Bonghan duct system, were first reported about 40 years ago, but have been largely ignored since then. Recently, they were rediscovered, and in this study we discuss the Feulgen reaction that specifically stains DNA in order to identify these structures on the surface of rabbit livers as part of the Bonghan system. The distribution, shapes, and sizes of their nuclei are found to be similar to those of intravascular threadlike structures. The endothelial nuclei are rod-shaped, 10-20 mum long, and aligned in a broken-line striped fashion. The threadlike structure consists of a bundle of several subducts, which is a characteristic feature of Bonghan ducts and distinguishes them morphologically from lymphatic vessels. In addition, the Feulgen reaction clearly demonstrates that the subducts pass through a corpuscle, which is usually irregular or oval-shaped and is connected to two or several threadlike structures that form a web on the surfaces of organs. Furthermore, spherical granules of about 1 mum in diameter are detected in the subducts. These granules were well stained by using the Feulgen reaction, which implies that they contain DNA. According to previous reports, a granule is a type of microcell and plays an essential role in the physiology and therapeutic effect of the Bonghan system and acupuncture. This role has yet to be elucidated.

Putative primo-vascular system in mesentery of rats.

Primo-vessels have been observed in the rat abdominal cavity as floating thread like structures on and not adhering to fascia-wrapped internal organs. To date their presence, locations, and lengths have been irregular and unpredictable, and their identification not regularly repeatable, thus they have remained a nagging enigma in primo-vascular system research for several years. In this work, locations were found where primo-vessels were regularly present and observed repeatedly. These vessels were not floating or freely movable but lay in a regular position in the mesentery in the abdominal cavity of the rat, being observed between the cecum and small intestine and between the colon and mesentery root. The difference between a lymph vessel and a primo-vessel is described in anatomical and histological aspects. In addition, trypan blue was found to enter primo-vessels through the surrounding membranes and filled spaces between fibers comprising the primo-vessels. It is conjectured that the previously observed floating primo-vessels had anomalously and irregularly emerged, for some unknown physiological reasons, from primo-vessels normally located in the fascia-like mesentery.

Comparative analysis of cell surface proteins in chronic and acute leukemia cell lines.

This study was designed to identify the cell surface protein markers that can differentiate between chronic myeloid leukemia (CML) and acute promyelocytic leukemia cells (APL). The differentially expressed plasma membrane proteins were analyzed between CML cell line (K562) and APL cell line (NB4) using the comparative proteomic approach. The cell membrane proteins were enriched by labeling with a membrane-impermeable biotinylation reagent, sulfo-NHS-SS-Biotin, and subjected to liquid chromatography tandem mass spectrometry (LC-MS/MS). By comparative proteomic analysis of K562 and NB4 cells, we identified 25 membrane and 14 membrane-associated proteins. The result of LC-MS/MS combined with chemical tagging method was validated by confirming the expression and localization of one of the differentially expressed plasma membrane proteins, CD43, by FACS and confocal microscopy. Our results indicate that CD43 could be a potential candidate for differentiating CML from APL.