Predictability-dependent encoding of statistical regularities in the early visual cortex

Previous research recognized that humans could extract statistical regularities of the environment to automatically predict upcoming events. However, it has remained unexplored how the brain encodes the distribution of statistical regularities if it continuously changes. To investigate this question, we devised an fMRI paradigm where participants (N = 32) completed a visual four-choice reaction time (RT) task consisting of statistical regularities. Two types of blocks involving the same perceptual elements alternated with one another throughout the task: While the distribution of statistical regularities was predictable in one block type, it was unpredictable in the other. Participants were unaware of the presence of statistical regularities and of their changing distribution across the subsequent task blocks. Based on the RT results, although statistical regularities were processed similarly in both the predictable and unpredictable blocks, participants acquired less statistical knowledge in the unpredictable as compared with the predictable blocks. Whole-brain random-effects analyses showed increased activity in the early visual cortex and decreased activity in the precuneus for the predictable as compared with the unpredictable blocks. Therefore, the actual predictability of statistical regularities is likely to be represented already at the early stages of visual cortical processing. However, decreased precuneus activity suggests that these representations are imperfectly updated to track the multiple shifts in predictability throughout the task. The results also highlight that the processing of statistical regularities in a changing environment could be habitual.

Crab-Eating Monkey Acidic Chitinase (CHIA) Efficiently Degrades Chitin and Chitosan under Acidic and High-Temperature Conditions

Chitooligosaccharides, the degradation products of chitin and chitosan, possess anti-bacterial, anti-tumor, and anti-inflammatory activities. The enzymatic production of chitooligosaccharides may increase the interest in their potential biomedical or agricultural usability in terms of the safety and simplicity of the manufacturing process. Crab-eating monkey acidic chitinase (CHIA) is an enzyme with robust activity in various environments. Here, we report the efficient degradation of chitin and chitosan by monkey CHIA under acidic and high-temperature conditions. Monkey CHIA hydrolyzed α-chitin at 50 °C, producing N-acetyl-D-glucosamine (GlcNAc) dimers more efficiently than at 37 °C. Moreover, the degradation rate increased with a longer incubation time (up to 72 h) without the inactivation of the enzyme. Five substrates (α-chitin, colloidal chitin, P-chitin, block-type, and random-type chitosan substrates) were exposed to monkey CHIS at pH 2.0 or pH 5.0 at 50 °C. P-chitin and random-type chitosan appeared to be the best sources of GlcNAc dimers and broad-scale chitooligosaccharides, respectively. In addition, the pattern of the products from the block-type chitosan was different between pH conditions (pH 2.0 and pH 5.0). Thus, monkey CHIA can degrade chitin and chitosan efficiently without inactivation under high-temperature or low pH conditions. Our results show that certain chitooligosaccharides are enriched by using different substrates under different conditions. Therefore, the reaction conditions can be adjusted to obtain desired oligomers. Crab-eating monkey CHIA can potentially become an efficient tool in producing chitooligosaccharide sets for agricultural and biomedical purposes.

FATIGUE ASSESSMENT OF SHIP SUPERSTRUCTURE AT EXPANSION JOINT

Despite the long history of application of subdivided superstructures and deckhouses, and efforts of ship designers and researchers a sensible solution in design of reliable details at the cut endings was not found yet. It may be explained as consequence of controversial requirements in design of the cut endings. Fatigue design of the superstructure details is addressed to solution of the problem. Presented is an example of fatigue design of the cut ending in a fast ship superstructure based on application of modified «Strain-Life» criterion for fatigue and subsequent approach which utilizes Neuber’s formula and material cyclic properties. To realize the approach a procedure of the long-term stress distribution transformation to the block-type format is developed. Efficiency of the developed technique is illustrated by comparing the results with those of application standard S-N criteria based techniques. The results of analysis allowed selection of the expansion joint detail of the superstructure geometry and construction procedure providing necessary reliability.

Evaluation of the Effectiveness of Modified Pectoral Nerve Blocks Type II (PECS II) for Vascular Access Port Implantation Using Cephalic Vein Venesection

The vascular access port implantation procedure can be performed using the venesection method by inserting a catheter into the cephalic vein in the region of the deltopectoral groove. This method eliminates the need for catheter tunneling. An alternative method to infiltration anaesthesia for port implantation may be a modified pectoral nerve block type II (PECS II). This study aimed to evaluate the effectiveness of modified PECS II for vascular access port implantation using cephalic vein venesection. This retrospective observational study was conducted at the 4th Military Clinical Hospital in Wroclaw, Poland. A group of 114 patients underwent the modified PECS II block and additional cutaneous infiltration anesthesia at the incision line. Pain intensity was assessed on the NRS scale measured intraoperatively at four points. The QoR-15 questionnaire was used to assess patient satisfaction during the first 24 h after surgery. The operator’s condition assessment score was used to assess surgical conditions and operator comfort. The analysis showed that the median pain intensity during vascular port implantation was 0. A statistically significant difference in pain intensity was demonstrated between the specialist’s group and the resident’s group at the second and third measurement points (p < 0.008; p < 0.012). The mean value on the QoR-15 scale was 132. There was a significant difference between the pain scores of the groups. The mean score in the pain position in the specialist’s group was 18 points and in the resident’s group, it was 19 points (p < 0.029). In conclusion, the present study revealed that the modified PECS II block is an effective and safe method of anesthesia for Port-A-Cath implantation.

Optimization of Video Cloud Gaming Using Fast HEVC Video Compression Technique

Cloud computing is a model of technology that offers access to system resources with advanced level of services ability. These resources are measured reliable, flexible and affordable for several kinds of applications and users. Gaming manufacturing is one filed that expands the profits of cloud computing as numerous new cloud gaming designs have been presented. Many advantages of cloud gaming have exaggerated the success of gaming based on the improvements on traditional online gaming. Though, cloud gaming grieves from several downsides such as the massive amount of needed video processing and the computational complexity required for that. This paper displays the original system drawbacks and develops a new and original algorithm to speed up the encoding process by reduces the computational complexity by exploiting the block type and location. Enhancements on the video codec led to 12.2% speeding up on the over-all encoding time with slight loss of users’ satisfactions. Keywords: Cloud gaming, Computational complexity, Motion estimation, HEVC, Video Encoding

Agromorphological Characterization of a Collection of Senna obtusifolia (L.) in Burkina Faso

Aims: Senna obtusifolia (L.) is an important wild herbaceous species for subsaharan Africa population. It is used in human food and traditional medicine to treat several deseases. In Burkina Faso, despite its potentialities, this species is of a little interest in scientific research. The aim of this study is to provide a good knowledge of the genetic diversity of this species. Study Design: The experimental design used was a randomized Fischer block type with three replications. Place and Duration of the Study: The study was carried out at Gampéla during 2018 rainy season. Methodology: Seventy (70) accessions of Senna obtusifolia were used for the evaluation of agromorphological variability. A total of twenty-seven (27) quantitative traits were studied. Results: The study revealed the existence of a great variability within the studied collection. Among the twenty-one (21) traits used for the analysis of variance (ANOVA), seventeen (17) variables significantly discriminate the accessions. A high heterogeneity was observed for the number of leaflets of the three first leaves and the number of floral pieces. In addition, significant correlations were observed between several variables. Indeed, the number of primary branches was positively correlated with the number of fruits per plant (r = 0.483), the number of grains per plant (r = 0.352) and the leaves biomass (r = 0.279). However, the number of days at flowering (NJF) is negatively correlated with the number of primary branches (r = -0.281). The variability obtained was structured in three groups. The third group is composed of accessions with the best agronomic performance that could be used in future breeding program. Conclusion: A high agromorphological diversity of Senna obtusifolia was observed and could be used in a breeding program.

Core and rod structures of a thermophilic cyanobacterial light-harvesting phycobilisome

Cyanobacteria, glaucophytes, and rhodophytes utilize giant, light-harvesting phycobilisomes (PBSs) for capturing solar energy and conveying it to photosynthetic reaction centers. PBSs are compositionally and structurally diverse, and exceedingly complex, all of which pose a challenge for a comprehensive understanding of their function. To date, three detailed architectures of PBSs by cryo-electron microscopy (cryo-EM) have been described: a hemiellipsoidal type, a block-type from rhodophytes, and a cyanobacterial hemidiscoidal-type. Here, we report cryo-EM structures of a pentacylindrical allophycocyanin core and phycocyanin-containing rod of a thermophilic cyanobacterial hemidiscoidal PBS. The structures define the spatial arrangement of protein subunits and chromophores, crucial for deciphering the energy transfer mechanism. They reveal how the pentacylindrical core is formed, identify key interactions between linker proteins and the bilin chromophores, and indicate pathways for unidirectional energy transfer.

Mouse Acidic Chitinase Effectively Degrades Random-Type Chitosan to Chitooligosaccharides of Variable Lengths under Stomach and Lung Tissue pH Conditions

Chitooligosaccharides exhibit several biomedical activities, such as inflammation and tumorigenesis reduction in mammals. The mechanism of the chitooligosaccharides’ formation in vivo has been, however, poorly understood. Here we report that mouse acidic chitinase (Chia), which is widely expressed in mouse tissues, can produce chitooligosaccharides from deacetylated chitin (chitosan) at pH levels corresponding to stomach and lung tissues. Chia degraded chitin to produce N-acetyl-d-glucosamine (GlcNAc) dimers. The block-type chitosan (heterogenous deacetylation) is soluble at pH 2.0 (optimal condition for mouse Chia) and was degraded into chitooligosaccharides with various sizes ranging from di- to nonamers. The random-type chitosan (homogenous deacetylation) is soluble in water that enables us to examine its degradation at pH 2.0, 5.0, and 7.0. Incubation of these substrates with Chia resulted in the more efficient production of chitooligosaccharides with more variable sizes was from random-type chitosan than from the block-type form of the molecule. The data presented here indicate that Chia digests chitosan acquired by homogenous deacetylation of chitin in vitro and in vivo. The degradation products may then influence different physiological or pathological processes. Our results also suggest that bioactive chitooligosaccharides can be obtained conveniently using homogenously deacetylated chitosan and Chia for various biomedical applications.