Neural Correlates Of Episodic Memory Formation In Children And Adults

The medial temporal lobe (MTL) and prefrontal cortex (PFC) are two key brain regions that support episodic memory formation in both children and adults, but the functional developmental of these regions remains unclear. In this study, we investigated the development of neural correlates of episodic memory formation using functional MRI with a subsequent memory paradigm, administered to a cross-sectional sample of 83 children and adults. We found that MTL subregions showed an age-related increase in activation supporting memory formation of complex scenes. In addition, a functionally defined scene-sensitive region in the posterior MTL also showed similar increase and predicted better memory for complex scenes. Within the PFC we found age-related increase in both activation and deactivation that support memory formation. Finally, we found age-related increase in the functional connectivity between dorsal lateral PFC and posterior MTL regions. Taken together, these findings suggest that the continued functional development of the MTL and the PFC is crucial for age-related improvements in memory

Self-Sacrificing Behavior of the Sponsoring Company and Participation Behavior of Community Members in the Crowdsourcing

Self-sacrificing behavior of the sponsoring company in the community is increasingly important to improve the active participation and organizational citizenship behavior of community members. However, our understanding of how self-sacrificing behavior influence the participation and behavior of community members remains limited. This study investigates the underlying influencing mechanism of the self-sacrificing behavior of the sponsoring company on the knowledge management process of community members in crowdsourcing communities and further examines the mediating effect of organizational identification. Based on 286 community members surveyed from the crowdsourcing communities of eight high-tech companies, we find that the self-sacrificing behavior of the company can help community members develop organizational identification, which leads to knowledge innovation and integration. Furthermore, we find that knowledge integration of crowdsourcing community members mediates the relationship between their organizational identification and knowledge innovation

Prevalence, antibiotic resistance and virulence feature of Listeria monocytogenes isolated from bovine milk in Yunnan, Southwest China

The prevalence of Listeria monocytogenes in bovine milk from different regions of Yunnan Province, Southwest China, was investigated. The isolated strains were genotyped using pulsed-field gel electrophoresis (PFGE), and their virulence and antibiotic resistance potential analysed with whole-genome sequencing (WGS). A total of 8 L. monocytogenes strains were isolated from 4 out of 161 samples, with a detection rate of 2.48%. All strains were at least resistant to one antibiotic, and the majority of strains (75%) were multi-antibiotic resistant. The 8 strains were clustered into 3 pulsotypes, and each pulsotype contained only strains isolated from the same geographical area. One strain was selected from each pulsotype for WGS, and it was found that a total of 99 antibiotic resistance genes and 83 virulence genes were detected from the 3 strains, respectively, which indicated that L. monocytogenes isolated from bovine milk have strong antibiotic resistance and virulence potential

Ask Questions with Double Hints: Visual Question Generation with Answer-awareness and Region-reference

The visual question generation (VQG) task aims to generate human-like questions from an image and potentially other side information (e.g. answer type). Previous works on VQG fall in two aspects: i) They suffer from one image to many questions mapping problem, which leads to the failure of generating referential and meaningful questions from an image. ii) They fail to model complex implicit relations among the visual objects in an image and also overlook potential interactions between the side information and image. To address these limitations, we first propose a novel learning paradigm to generate visual questions with answer-awareness and region-reference. Concretely, we aim to ask the right visual questions with Double Hints - textual answers and visual regions of interests, which could effectively mitigate the existing one-to-many mapping issue. Particularly, we develop a simple methodology to self-learn the visual hints without introducing any additional human annotations. Furthermore, to capture these sophisticated relationships, we propose a new double-hints guided Graph-to-Sequence learning framework, which first models them as a dynamic graph and learns the implicit topology end-to-end, and then utilizes a graph-to-sequence model to generate the questions with double hints. Experimental results demonstrate the priority of our proposed method

Biogeographic patterns and drivers of soil viromes

Viruses are crucial in shaping soil microbial functions and ecosystems. However, studies on soil viromes have been limited in both spatial scale and biome coverage. Here we present a comprehensive synthesis of soil virome biogeographic patterns using the Global Soil Virome dataset (GSV) wherein we analysed 1,824 soil metagenomes worldwide, uncovering 80,750 partial genomes of DNA viruses, 96.7% of which are taxonomically unassigned. The biogeography of soil viral diversity and community structure varies across different biomes. Interestingly, the diversity of viruses does not align with microbial diversity and contrasts with it by showing low diversity in forest and shrubland soils. Soil texture and moisture conditions are further corroborated as key factors affecting diversity by our predicted soil viral diversity atlas, revealing higher diversity in humid and subhumid regions. In addition, the binomial degree distribution pattern suggests a random co-occurrence pattern of soil viruses. These findings are essential for elucidating soil viral ecology and for the comprehensive incorporation of viruses into soil ecosystem models

Neural Correlates of Syntax and Proto-Syntax: Evolutionary Dimension

The present fMRI study tested predictions of the evolution-of-syntax framework which analyzes certain structures as remnants (“fossils”) of a non-hierarchical (non-recursive) proto-syntactic stage in the evolution of language (Progovac, 2015, 2016). We hypothesized that processing of these structures, in comparison to more modern hierarchical structures, will show less activation in the brain regions that are part of the syntactic network, including Broca’s area (BA 44 and 45) and the basal ganglia, i.e., the network bolstered in the line of descent of humans through genetic mutations that contributed to present-day dense neuronal connectivity among these regions. Fourteen healthy native English-speaking adults viewed written stimuli consisting of: (1) full sentences (FullS; e.g., The case is closed); (2) Small Clauses (SC; e.g., Case closed); (3) Complex hierarchical compounds (e.g., joy-killer); and (4) Simple flat compounds (e.g., kill-joy). SC (compared to FullS) resulted in reduced activation in the left BA 44 and right basal ganglia. Simple (relative to complex) compounds resulted in increased activation in the inferior temporal gyrus and the fusiform gyrus (BA 37/19), areas implicated in visual and semantic processing. We discuss our findings in the context of current theories regarding the co-evolution of language and the brain

Room temperature all-solid-state lithium batteries based on a soluble organic cage ionic conductor

All solid-state lithium batteries (SSLBs) are poised to have higher energy density and better safety than current liquid-based Li-ion batteries, but a central requirement is effective ionic conduction pathways throughout the entire cell. Here we develop a catholyte based on an emerging class of porous materials, porous organic cages (POCs). A key feature of these Li(+) conducting POCs is their solution-processibility. They can be dissolved in a cathode slurry, which allows the fabrication of solid-state cathodes using the conventional slurry coating method. These Li(+) conducting cages recrystallize and grow on the surface of the cathode particles during the coating process and are therefore dispersed uniformly in the slurry-coated cathodes to form a highly effective ion-conducting network. This catholyte is shown to be compatible with cathode active materials such as LiFePO(4), LiCoO(2) and LiNi(0.5)Co(0.2)Mn(0.3)O(2), and results in SSLBs with decent electrochemical performance at room temperature

Characterizing The Development Of Episodic Memory And Assessing The Reliability Of Fmri Measures

The ability to remember past events is critical for everyday life and showed robust improvement over development from childhood to adulthood. With advances in noninvasive neuroimaging methods such as functional MRI in recent years, research efforts have been focused on identifying neural correlates underpinning developmental gains in memory performance. In my dissertation work, using a widely-validated subsequent memory paradigm, I aim to characterize functional MRI correlates of memory development. Specifically, I focused my investigation on identifying age differences in the functional patterns of two brain regions critical for memory, the prefrontal cortex and the hippocampus. Focusing on the prefrontal cortex (Chapter 1), I found memory-related activation in inferior frontal gyrus and memory-related deactivation in superior frontal gyrus. Both regions demonstrated developmental effects, but only memory-related deactivation in superior prefrontal cortex mediated the relationship between age and memory performance. The prefrontal cortex showed dynamic developmental effects in its functional connectivity with the medial temporal lobe, including parahippocampal gyrus. Focusing on the hippocampus (Chapter 2), I found that both anterior and posterior hippocampus supported memory formation, with effects that are relatively stable from ages 8 to 25 years. Differential developmental patterns were found for the functional connectivity between hippocampal subregions and prefrontal/visual cortices, suggesting increased functional specialization along the long axis of the hippocampus. Lastly, I tackled critical yet often neglected concerns over the reliability in identifying neural correlates of memory with fMRI (Chapter 3). I estimated the reliability of subsequent memory effects using an independent reliability dataset (n=24, ages 8 to 20 years), with a similar focus on the prefrontal cortex and the hippocampus. Good to excellent test-retest reliability was observed on the group-level contrast, corresponding to group-level analyses with a cross-sectional design. On the individual level, good reliability was observed in cortical regions including the prefrontal cortex and parahippocampal gyrus, but not in the hippocampus. Collectively, through critical evaluation and rigorous analyses, I have made important contributions to the field by providing novel insights into how traditionally-defined “memory-regions” dynamically support memory development on a granular, subregion level. In addition, my work has contributed in establishing the much-needed boundaries to the extent to which fMRI measures can be applied to answer important questions in memory development