Position-element frequency learning is dissociable from Hebb repetition learning

Position-element association has been extensively investigated as a mechanism for serial order memory and has been widely implemented in models of short-term memory. This study examined whether and how the position-element association is learned as a form of long-term knowledge dissociated from other forms of knowledge such as sequence knowledge acquired in the Hebb list repetition paradigm. Laboratory learning experiments demonstrated that repeated exposure to a specific position-element association facilitated subsequent recall of the position-element association with experimental control of other aspects of to-be-learned statistical structure of the artificial phonotactics. The experiments also demonstrated that the positional frequency learning was more gradual than Hebb list learning, suggesting a dissociation of the two forms of learning. Functional roles of these two forms of learning were discussed

The interaction between temporal grouping and phonotactic chunking in short-term serial order memory for novel verbal sequences

The current study investigated the ways long-term memory contributes to short-term serial order memory of novel verbal sequences, focusing on long-term knowledge of bi-element frequency, that is, co-occurrence frequency of two consecutive elements in a linguistic environment. Participants performed two types of immediate serial recall of nine-element (nine-mora) sequences: low bi-mora frequency sequences where all eight associations between the nine morae were low frequency, and mixed bi-mora frequency sequences, with high-frequency associations for six of the eight bi-morae. Experiment 1 confirmed the bi-directional bi-mora frequency effect, meaning better recall performance for morae having high-frequency association with either the preceding mora (forward association) or the following mora (backward association). In Experiment 2, two temporal pauses were inserted in each list to disrupt high-frequency associations with the preceding mora or the following mora. The results showed that the bi-element frequency effect diminished when the high-frequency backward association was disrupted but the effect remained when the high-frequency forward association was disrupted. We discuss possible mechanisms underlying the asymmetric influence of temporal pauses on interactions between short-term memory and linguistic long-term memory

A digital multilayer neural network with limited binary expressions

金沢大学大学院自然科学研究科情報システムA design methodology is presented for digital multilayer neural networks with limited binary expressions. An error back-propagation algorithm is modified as follows: the numbers of binary bits used for connections and unit outputs are decreased step by step in the training process. In order to express unit outputs with two-level values, the differential of the logistic function is replaced by a small positive constant used in weight change equations. After the training is completed, binary expressions for connections and unit outputs can be reduced to several-bit and two-level values, respectively. Therefore, no multipliers or nonlinear functions are required in the resulting network, which will be used for pattern recognition. Furthermore, memory capacity and adder circuit hardware can be reduced. The network performance is also insensitive to noisy patterns

Extensive genomic diversity and selective conservation of virulence determinants in enterohemorrhagic Escherichia coli strains of O157 and non O157 serotypes

Background: Enterohemorrhagic Escherichia coli (EHEC) O157 causes severe food-borne illness in humans. The chromosome of O157 consists of 4.1 Mb backbone sequences shared by benign E. coli K-12, and 1.4 Mb O157-specific sequences encoding many virulence determinants, such as Shiga toxin genes (stx genes) and the locus of enterocyte effacement (LEE). Non-O157 EHECs belonging to distinct clonal lineages from O157 also cause similar illness in humans. According to the "parallel" evolution model, they have independently acquired the major virulence determinants, the stx genes and LEE. However, the genomic differences between O157 and non-O157 EHECs have not yet been systematically analyzed. Results: Using microarray and whole genome PCR scanning analyses, we performed a whole genome comparison of 20 EHEC strains of O26, O111, and O103 serotypes with O157. In non-O157 EHEC strains, although genome sizes were similar with or rather larger than O157 and the backbone regions were well conserved, O157-specific regions were very poorly conserved. Around only 20% of the O157- specific genes were fully conserved in each non-O157 serotype. However, the non-O157 EHECs contained a significant number of virulence genes that are found on prophages and plasmids in O157, and also multiple prophages similar to, but significantly divergent from, those in O157. Conclusion: Although O157 and non-O157 EHECs have independently acquired a huge amount of serotype- or strain-specific genes by lateral gene transfer, they share an unexpectedly large number of virulence genes. Independent infections of similar but distinct bacteriophages carrying these virulence determinants are deeply involved in the evolution of O157 and non-O157 EHECs

PPP2R1A (protein phosphatase 2 regulatory subunit A, alpha)

Review on PPP2R1A, with data on DNA, on the protein encoded, and where the gene is implicated

Determining the developmental requirements for Hebb repetition learning in young children:Grouping, short-term memory, and their interaction

The Hebb repetition paradigm has recently attracted attention as a measure of serial order learning, which underlies word-form learning abilities. Although children are good vocabulary learners, it is surprising that previous Hebb learning studies with young children show rather weak Hebb effects. In this study, we conducted two experiments to identify developmental factors that drive an increase of the size of the Hebb effect in young children. Motivated by evidence from adult work, we focused on an ability to group a sequence into consistent subsequences and on phonological short-term memory (STM) capacity. In Experiment 1 (N = 98), it was shown that 3- to 5-year-old children with high phonological STM capacity showed a Hebb effect, particularly in the later experimental trials. In Experiment 2 (N = 97), temporal grouping of the sequences in 2–2 subsequences further encouraged children with high phonological STM capacity to show the Hebb effect even in the earlier experimental trials and children with low STM capacity to show a trend toward a Hebb effect in the later trials. Moreover, across Experiments 1 and 2 we found robust evidence of transfer of the Hebb effect to recall of new sequences that partially overlapped in item-by-item pairings with the Hebb sequence, indicating that children use consistent grouping strategies when learning above-span Hebb sequences. These findings indicate that phonological STM, grouping consistency, and their interaction are developmental requirements for the Hebb effect to emerge

Multicenter phase II trial of preoperative chemoradiotherapy with S-1 for locally advanced oral squamous cell carcinoma

PURPOSE: We evaluated whether preoperative chemotherapy with S-1 and concurrent radiotherapy is feasible and efficacious in the treatment of advanced oral squamous cell carcinoma. METHODS: Participants comprised 39 patients with oral carcinoma (stage III, n = 15; stage IVA, n = 24). All patients received a total radiation dose of 40 Gy, in once-daily 2-Gy fractions, and received S-1 at 65 mg/m(2)/day for 5 consecutive days, over 4 consecutive weeks with concurrent radiotherapy. RESULTS: Hematological toxicity was mild and reversible. The most common non-hematological toxicity was grade 3 mucositis, but this was transient and tolerable. Radical surgery was performed for 37 patients, with the remaining 2 patients declining the surgery. Postoperatively, local failure developed in 1 patient, and neck failure in 2 patients. Distant metastases were identified in 4 patients. At a median follow-up of 38.0 months (range 23–88 months), locoregional control, disease-specific survival, and overall survival rates at 3 years were 91.5, 83.8, and 83.8 %, respectively. CONCLUSION: Concurrent administration of S-1 and radiotherapy combined with surgery offers a well-tolerated method of successfully treating advanced oral squamous cell carcinoma. The locoregional control rate remains high even at 3 years of follow-up, and no serious adverse effects have been encountered

Computer-aided Surgical Planning of Anterior Cruciate Ligament Reconstruction in MR Images

AbstractAnterior cruciate ligament (ACL) injury causes knee joint instability, and effects on sports performance. Therefore, ACL reconstruction is essential to keep their high performance. It is well known that the outcome of ACL reconstruction is strongly related to the placement and orientation of the bone tunnel. Therefore, optimization of tunnel drilling technique is an important factor to obtain satisfactory surgical results. Current procedure relies on arthroscopic evaluation and there is a risk of damaging arteries and ligaments during surgery. The damages may reduce the accuracy and reproducibility of ACL reconstruction. As a postoperative evaluation method, a quadrant method has been used to evaluate the placement and orientation of the bone tunnel in X-ray radiography. This study proposes a computer-aided surgical planning system for evaluating ACL insertion site and orientation using magnetic resonance (MR) images. We first introduce MR image based the quadrant method to determine the ACL insertion site for preoperative patients. It also evaluates the 3-D spatial relationship between the planning femoral drilling hole and arteries around the femoral condyle. This system has been applied to ACL injured patients, it may increase the accuracy and reproducibility of ACL bone tunnel, and it can evaluate a risk of damaging the surrounding arteries and ligaments