Simulating Problem Difficulty in Arithmetic Cognition Through Dynamic Connectionist Models

The present study aims to investigate similarities between how humans and connectionist models experience difficulty in arithmetic problems. Problem difficulty was operationalized by the number of carries involved in solving a given problem. Problem difficulty was measured in humans by response time, and in models by computational steps. The present study found that both humans and connectionist models experience difficulty similarly when solving binary addition and subtraction. Specifically, both agents found difficulty to be strictly increasing with respect to the number of carries. Another notable similarity is that problem difficulty increases more steeply in subtraction than in addition, for both humans and connectionist models. Further investigation on two model hyperparameters --- confidence threshold and hidden dimension --- shows higher confidence thresholds cause the model to take more computational steps to arrive at the correct answer. Likewise, larger hidden dimensions cause the model to take more computational steps to correctly answer arithmetic problems; however, this effect by hidden dimensions is negligible.Comment: 7 pages; 15 figures; 5 tables; Published in the proceedings of the 17th International Conference on Cognitive Modelling (ICCM 2019

Comparison of Oxygen Flux in Hydrogel and Silicone Hydrogel Contact Lenses

The prevalence of contact lens use has been continuously growing for their convenience and for cosmetic reasons. Although contact lenses do offer many advantages over glasses, the major concern for many contact lens users is dryness that results from a lack of oxygen that goes through the contact lens to meet the demand of eye tissue. A new type of contact lens, made out of silicone hydrogel, has been introduced in the market which has garnered much attention from many contact users. The silicone hydrogel is different from the traditional hydrogel contact lens since oxygen is permeable through silicone, which was not possible through hydrogels. The hydrogel contact lenses must have high water content for oxygen delivery, silicone hydrogel contacts depends on their high oxygen diffusivity while having low water content. Night and day contact lenses are made out of silicone hydrogel whereas traditional ones for day use are often made out of hydrogel. A model was developed to validate the advantage of wearing silicone hydrogel contact lenses in both day and night conditions. By analyzing the center area of the eye around the pupil as a thin slab, the performance of these two types of contact lenses were compared by computing average oxygen concentrations in the stroma, which is the largest layer of cornea. Using COMSOL Multiphysics, the simplified geometry that included the layers of contact lens, tear, endothelium, and stroma was used as our model to find the oxygen concentration after eight hours of use either with eyes open or closed. The thickness of 80/mu m was used for both hydrogel and silicone hydrogel, the average oxygen concentration was found to be 9.100219x10-8mol/cm3 and 4.198608x10-8 mol/cm3 respectively for day setting with eyes open for eight hours and 3.536442x10-8 mol/cm3 and 2.119774x10-8 mol/cm3 respectively for night setting with eyes closed. Variations of other parameters in modeling also showed the same trend that silicone hydrogel contact lenses ended up with less oxygen in the cornea than hydrogel. Thus, the modeling showed how the silicone hydrogel did not offer any increase in oxygen delivery in both day and night settings

Database Security System for Applying Sophisticated Access Control via Database Firewall Server

Database security, privacy, access control, database firewall, data break masking Recently, information leakage incidents have occurred due to database security vulnerabilities. The administrators in the traditional database access control methods grant simple permissions to users for accessing database objects. Even though they tried to apply more strict permissions in recent database systems, it was difficult to properly adopt sophisticated access control policies to commercial databases due to performance degradations. This paper proposes a database security system including a database firewall server as an enhanced database access control system which can efficiently enforce sophisticated security policies to provide database with confidentiality using a data masking technique for diverse conditions such as the date, time, SQL string, and table columns to database systems

'Choosing shoes': a preliminary study into the challenges facing clinicians in assessing footwear for rheumatoid patients

Background: Footwear has been accepted as a therapeutic intervention for the foot affected by rheumatoid arthritis (RA). Evidence relating to the objective assessment of footwear in patients with RA is limited. The aims of this study were to identify current footwear styles, footwear characteristics, and factors that influence footwear choice experienced by patients with RA. Methods: Eighty patients with RA were recruited from rheumatology clinics during the summer months. Clinical characteristics, global function, and foot impairment and disability measures were recorded. Current footwear, footwear characteristics and the factors associated with choice of footwear were identified. Suitability of footwear was recorded using pre-determined criteria for assessing footwear type, based on a previous study of foot pain. Results: The patients had longstanding RA with moderate-to severe disability and impairment. The foot and ankle assessment demonstrated a low-arch profile with both forefoot and rearfoot structural deformities. Over 50% of shoes worn by patients were opentype footwear. More than 70% of patients’ footwear was defined as being poor. Poor footwear characteristics such as heel rigidity and sole hardness were observed. Patients reported comfort (17%) and fit (14%) as important factors in choosing their own footwear. Only five percent (5%) of patients wore therapeutic footwear. Conclusions: The majority of patients with RA wear footwear that has been previously described as poor. Future work needs to aim to define and justify the specific features of footwear that may be of benefit to foot health for people with RA

The Effect of Neuromuscular Blockade Reversal Agents on Postoperative Pulmonary Complications in Patients undergoing Femur Fracture Repair Surgery: A Retrospective Observational Study

Background Femoral fracture repair surgery under general anesthesia is associated with postoperative pulmonary complications (PPCs). However, information on PPCs caused by residual neuromuscular blockade following perioperative use of neuromuscular blockers is limited. This study aimed to identify the differences in the incidence of PPCs according to the type of neuromuscular blockade reversal agent used in femoral fracture repair surgery, as well as the risk factors for PPCs. Methods We retrospectively analyzed the electronic medical records of 604 patients aged >18 years who underwent general anesthesia for femoral fracture repair surgery at a single university hospital between March 2017 and March 2022. Patients in whom sugammadex or anticholinesterase was used to reverse the neuromuscular block were subjected to propensity score matching. Multivariate logistic regression analysis was performed to identify risk factors for PPCs. Results Among the 604 patients, 108 were matched in each group. The incidence rates of PPCs overall and in the anticholinesterase and sugammadex groups were 7.0%, 8.3%, and 5.6%, respectively, with no significant differences between the groups. Older age, higher ASA (American Society of Anesthesiologists) physical status, and lower preoperative oxygen saturation were risk factors, whereas emergency surgery was a preventive factor. Conclusions Our results demonstrated that the incidence of PPC did not differ significantly between sugammadex and anticholinesterase in patients undergoing femur fracture repair under general anesthesia. Identifying the risk factors and confirming complete recovery from neuromuscular blockade might be more important

Culture supernatant of adipose stem cells can ameliorate allergic airway inflammation via recruitment of CD4+CD25+Foxp3 T cells

SDS-PAGE of supernatant after ASC cultivation. Comparison of protein composition of con sup (concentrated medium for ASCs cultivation) and ASC sup (concentrated culture supernatant after ASC cultivation for 3 days) using SDS-PAGE. Thirty micrograms of each sample was loaded into an SDS-PAGE gel. After electrophoresis, the gel was stained by Coomassie Blue (M molecular marker, arrow indicated extra proteins compared to control). (PPT 370 kb

(E)-9-(4-Chloro­styr­yl)-3,4,5,6,7,9-hexa­hydro-2H-xanthene-1,8-dione

In the title compound, C21H19ClO3, the two cyclo­hexenone rings adopt half-chair conformations, whereas the pyran ring adopts a boat conformation. The 4-chloro­phenyl ring is almost perpendicular to the plane through the four C atoms of the pyran ring [dihedral angle = 87.97 (6)°]. In the crystal, weak C—H⋯O hydrogen bonds link the mol­ecules into a chain parallel to the a-axis

Lattice-patterned LC-polymer composites containing various nanoparticles as additives

In this study, we show the effect of various nanoparticle additives on phase separation behavior of a lattice-patterned liquid crystal [LC]-polymer composite system and on interfacial properties between the LC and polymer. Lattice-patterned LC-polymer composites were fabricated by exposing to UV light a mixture of a prepolymer, an LC, and SiO2 nanoparticles positioned under a patterned photomask. This resulted in the formation of an LC and prepolymer region through phase separation. We found that the incorporation of SiO2 nanoparticles significantly affected the electro-optical properties of the lattice-patterned LC-polymer composites. This effect is a fundamental characteristic of flexible displays. The electro-optical properties depend on the size and surface functional groups of the SiO2 nanoparticles. Compared with untreated pristine SiO2 nanoparticles, which adversely affect the performance of LC molecules surrounded by polymer walls, SiO2 nanoparticles with surface functional groups were found to improve the electro-optical properties of the lattice-patterned LC-polymer composites by increasing the quantity of SiO2 nanoparticles. The surface functional groups of the SiO2 nanoparticles were closely related to the distribution of SiO2 nanoparticles in the LC-polymer composites, and they influenced the electro-optical properties of the LC molecules. It is clear from our work that the introduction of nanoparticles into a lattice-patterned LC-polymer composite provides a method for controlling and improving the composite's electro-optical properties. This technique can be used to produce flexible substrates for various flexible electronic devices