Conservative Likelihood Ratio Estimator for Infrequent Data Slightly above a Frequency Threshold

A naive likelihood ratio (LR) estimation using the observed frequencies of events can overestimate LRs for infrequent data. One approach to avoid this problem is to use a frequency threshold and set the estimates to zero for frequencies below the threshold. This approach eliminates the computation of some estimates, thereby making practical tasks using LRs more efficient. However, it still overestimates LRs for low frequencies near the threshold. This study proposes a conservative estimator for low frequencies, slightly above the threshold. Our experiment used LRs to predict the occurrence contexts of named entities from a corpus. The experimental results demonstrate that our estimator improves the prediction accuracy while maintaining efficiency in the context prediction task.Comment: The 9th International Conference on Advanced Informatics: Concepts, Theory and Applications (ICAICTA 2022

A Computational Model of Tonality Cognition Based on Prime Factor Representation of Frequency Ratios and Its Application

(Abstract to follow

Rupture of Internal carotid artery pseudoaneurysm in the sphenoid sinus as a complication of deep neck space infection

Background : Pseudoaneurysm of the internal carotid artery (ICA) is a very rare but potentially fatal complication of deep neck space infection. Methods : This paper describes a very rare case of an ICA pseudoaneurysm rupture in the sphenoid sinus caused by a deep neck abscess. Results : A 62-year-old male with a deep neck space infection underwent surgical drainage. On the postoperative 21st day, however, he suddenly had massive epistaxis. A transnasal endoscopic examination found massive bleeding out of the sphenoid sinus. Immediate intra-arterial angiography revealed two pseudoaneurysms of the left ICA at the cavernous segment (C4) and the clinoid segment (C5), which were embolized with coils. The patient made an uneventful recovery after the embolization. Conclusion : We found no reports in the literature that pseudoaneurysms associated with a deep neck infection rupture in the sphenoid sinus. Prompt treatment along with accurate diagnosis is essential for successful management of such cases

Individual differences and course attendance: Why do students skip class?

Individual differences are theorised as being key predictors of students’ lecture attendance. Understanding students’ (lack of) motivation for studying is an essential first step in supporting these individual differences and potentially increasing class/lecture attendance. The current study explored the role of students’ deficits in motivations (ability/effort/task value) for studying and their predictive relationship with course attendance, while controlling for prior competence and academic self-concept. Second-year students (n = 219; Female = 40) undertaking three semester-long courses in English as a foreign language participated in the year-long study. The structural model tested included prior achievement and self-concept (Time-1; 15 weeks prior), the motivational deficits for studying in the course (Time-2; ability, effort and task value), and class attendance across the two semesters of study. Self-concept negatively predicted all motivational deficits (moderate-large effects), and positively predicted attendance. Two of the motivational deficits (ability and effort) also had strongly contrasting effects (positive and negative respectively) on attendance. The implications and practical suggestions for intervention are discussed

Roles of Phosphate in Skeleton

Phosphate is essential for skeletal mineralization, and its chronic deficiency leads to rickets and osteomalacia. Skeletal mineralization starts in matrix vesicles (MVs) derived from the plasma membrane of osteoblasts and chondrocytes. MVs contain high activity of tissue non-specific alkaline phosphatase (TNSALP), which hydrolyzes phosphoric esters such as pyrophosphates (PPi) to produce inorganic orthophosphates (Pi). Extracellular Pi in the skeleton is taken up by MVs through type III sodium/phosphate (Na+/Pi) cotransporters and forms hydroxyapatite. In addition to its roles in MV-mediated skeletal mineralization, accumulating evidence has revealed that extracellular Pi evokes signal transduction and regulates cellular function. Pi induces apoptosis of hypertrophic chondrocytes, which is a critical step for endochondral ossification. Extracellular Pi also regulates the expression of various genes including those related to proliferation, differentiation, and mineralization. In vitro cell studies have demonstrated that an elevation in extracellular Pi level leads to the activation of fibroblast growth factor receptor (FGFR), Raf/MEK (mitogen-activated protein kinase/ERK kinase)/ERK (extracellular signal-regulated kinase) pathway, where the type III Na+/Pi cotransporter PiT-1 may be involved. Responsiveness of skeletal cells to extracellular Pi suggests their ability to sense and adapt to an alteration in Pi availability in their environment. Involvement of FGFR in the Pi-evoked signal transduction is interesting because enhanced FGFR signaling in osteoblasts/osteocytes might be responsible for the overproduction of FGF23, a key molecule in phosphate homeostasis, in a mouse model for human X-linked hypophosphatemic rickets (XLH). Impaired Pi sensing may be a pathogenesis of XLH, which needs to be clarified in future