An easy iris center detection method for eye gaze tracking system

Iris center detection accuracy has great impact on eye gaze tracking system performance. This paper proposes an easy and efficient iris center detection method based on modeling the geometric relationship between the detected rough iris center and the two corners of the eye. The method fully considers four states of iris within the eye region, i.e. center, left, right, and upper. The proposed active edge detection algorithm is utilized to extract iris edge points for ellipse fitting. In addition, this paper also presents a predicted edge point algorithm to solve the decrease in ellipse fitting accuracy, when part of the iris becomes hidden from rolling into a nasal or temporal eye corner. The evaluated result of the method on our eye database shows the global average accuracy of 94.3%. Compared with existing methods, our method achieves the highest iris center detection accuracy. Additionally, in order to test the performance of the proposed method in gaze tracking, this paper presents the results of gaze estimation achieved by our eye gaze tracking system

Competition between Replicative and Translesion Polymerases during Homologous Recombination Repair in Drosophila

In metazoans, the mechanism by which DNA is synthesized during homologous recombination repair of double-strand breaks is poorly understood. Specifically, the identities of the polymerase(s) that carry out repair synthesis and how they are recruited to repair sites are unclear. Here, we have investigated the roles of several different polymerases during homologous recombination repair in Drosophila melanogaster. Using a gap repair assay, we found that homologous recombination is impaired in Drosophila lacking DNA polymerase zeta and, to a lesser extent, polymerase eta. In addition, the Pol32 protein, part of the polymerase delta complex, is needed for repair requiring extensive synthesis. Loss of Rev1, which interacts with multiple translesion polymerases, results in increased synthesis during gap repair. Together, our findings support a model in which translesion polymerases and the polymerase delta complex compete during homologous recombination repair. In addition, they establish Rev1 as a crucial factor that regulates the extent of repair synthesis

Assessing the medical resources in COVID-19 based on evolutionary game

COVID-19 has brought a great challenge to the medical system. A key scientific question is how to make a balance between home quarantine and staying in the hospital. To this end, we propose a game-based susceptible-exposed-asymptomatic -symptomatic- hospitalized-recovery-dead model to reveal such a situation. In this new framework, time-varying cure rate and mortality are employed and a parameter m is introduced to regulate the probability that individuals are willing to go to the hospital. Through extensive simulations, we find that (1) for low transmission rates (β 0.2), large values of m lead to breakdown of the healthcare system, which will further increase the cumulative number of confirmed cases and death cases. Finally, we conduct the empirical analysis using the data from Japan and other typical countries to illustrate the proposed model and to test how our model explains reality

A System Dynamics Model for Assessing the Efficacy of Lethal Control for Sustainable Management of <i>Ochotona curzoniae</i> on Tibetan Plateau

When population abundances exceed the economical or ecological threshold, animals are always regarded as pests, so effective and sustainable management strategies are required. As a native species widely distributed on Tibetan Plateau, plateau pika is regarded as a pest when its abundance is too high. For decades, plateau pika were controlled using toxic baits by both the local government and shepherds. However, how pika population fluctuates after lethal control is far from certain. Based on our previous studies, demographic parameters of plateau pika were acquired. A system dynamics model is developed to parameterize a population model for this species. The model incorporates two age categories (juvenile and adult) of both sexes, and uses density-dependent factors, including reproduction, mortality, and migration. The model is used originally to analyze the effect of pika management on the population dynamics and resulting abundance, in order to plan optimal pest controlling strategies. The results show that lethal control is efficient when continuously conducted once each year, or twice with 2-year intervals. For sustainable controlling pest abundance, comprehensive strategies should be considered. An appropriate population model could be used to explore the optimal strategies and provide important reference into decision making about pest management

A High-Precision Method for 100-Day-Old Classification of Chickens in Edge Computing Scenarios Based on Federated Computing

Due to the booming development of computer vision technology and artificial intelligence algorithms, it has become more feasible to implement artificial rearing of animals in real production scenarios. Improving the accuracy of day-age detection of chickens is one of the examples and is of great importance for chicken rearing. This paper focuses on the problem of classifying the age of chickens within 100 days. Due to the huge amount of data and the different computing power of different devices in practical application scenarios, it is important to maximize the computing power of edge computing devices without sacrificing accuracy. This paper proposes a high-precision federated learning-based model that can be applied to edge computing scenarios. In order to accommodate different computing power in different scenarios, this paper proposes a dual-ended adaptive federated learning framework; in order to adapt to low computing power scenarios, this paper performs lightweighting operations on the mainstream model; and in order to verify the effectiveness of the model, this paper conducts a number of targeted experiments. Compared with AlexNet, VGG, ResNet and GoogLeNet, this model improves the classification accuracy to 96.1%, which is 14.4% better than the baseline model and improves the Recall and Precision by 14.8% and 14.2%, respectively. In addition, by lightening the network, our methods reduce the inference latency and transmission latency by 24.4 ms and 10.5 ms, respectively. Finally, this model is deployed in a real-world application and an application is developed based on the wechat SDK

Altered attentive bias towards interpersonal communication information across phases of schizophrenia: an eye-tracking study

Background Eye movement abnormality in schizophrenia has been studied for several decades. However, patient differences in eye movements across phases of schizophrenia from eye-tracking studies have not been well documented. Aims This pilot study used eye-tracking technology to investigate attentive bias towards interpersonal communication information across different clinical phases of schizophrenia. Methods This study included 78 persons at clinical high risk (CHR) for schizophrenia, 68 first-episode (FEZ) patients, and 39 chronically ill patients from the Shanghai At Risk for Psychosis Extending Project (SHARP Extending cohort) as well as 74 healthy controls (HCs). The experiment was an unguided-viewing task composed of 24 trials showing three types of pictures which varied in the degree of interpersonal communication. Type 1 was a scenery picture without people, type 2 was a picture with four people not communicating, and type 3 was a picture with four people communicating. We used two measures: (1) initial fixation duration and (2) total fixation duration. Results A ratio for both measures was calculated between measures for pictures with more or less interpersonal communication. The ratio of initial fixation duration for pictures with people communicating versus pictures with people not communicating was lowest in chronically ill patients (0.13 (0.34))compared with HCs (0.31 (0.36)), FEZ patients (0.31 (0.46)), and CHR patients (0.36 (0.42)). The difference in the ratios of initial fixation duration for type 2 and type 3 pictures was also significant for female participants (HCs vs chronically ill patients, t=2.706, p=0.009; CHR patients vs chronically ill patients, t=4.079, p<0.001). In addition, the ratio of initial fixation duration on pictures with people not communicating versus pictures without people negatively correlated with participants' high-risk symptoms (r=-0.35, p=0.002) among the CHR group and also correlated with the negative symptom subscore on the Positive and Negative Syndrome Scale (PANSS) among chronically ill patients (r=-0.33, p=0.037). The ratio of initial fixation duration between type 1 and type 3 pictures was associated with PANSS negative symptoms only in female patients with schizophrenia (r=-0.46, p=0.004). Conclusions These findings suggest an altered attentive bias towards pictures with a high degree of interpersonal communication information across different clinical phases in schizophrenia. The ratio of initial attentive orienting was associated with negative symptoms in female patients

Data from: Nitrogen controls the net primary production of an alpine Kobresia meadow in the northern Qinghai-Tibet Plateau

Net primary production (NPP) is a fundamental property of natural ecosystems. Understanding the temporal variations of NPP could provide new insights into the responses of communities to environmental factors, whilst also contributing to a better assessment of regional carbon storage. However, few studies based on long-term field biomass measurements have directly addressed this subject in the unique environment of the Qinghai-Tibet plateau (QTP). we examined the interannual variations of NPP during 2008-2015 by monitoring both aboveground net primary productivity (ANPP) and belowground net primary productivity (BNPP), and identified their relationships with environmental factors by adopted the general linear model (GLM)and structural equation model (SEM). In addition, the interannual variation of root turnover and its controls were also investigated. The results show that the ANPP and BNPP increased by rates of 15.01 g/m2 and 143.09 g/m2 per year during 2008-2015, respectively. BNPP was mainly affected by growing season air temperature (GST) and growing season precipitation (GSP) rather than mean annual air temperature (MAT) or mean annual precipitation (MAP), while ANPP was only controlled by GST. In addition, available nitrogen (AN) was significant positively associated with BNPP and ANPP. Root turnover rate averaged 30% /yr, increased with soil depth, and was largely controlled by GST. Our results suggest that alpine Kobresia meadow was an N-limited ecosystem, the NPP on the QTP might increase further in the future in the context of global warming and nitrogen deposition

Data from: Moderate grazing promotes the root biomass in Kobresia meadow on the northern Qinghai-Tibet Plateau

Grazing is an important modulator of both plant productivity and biodiversity in grassland community, yet how to determine a suitable grazing intensity in alpine grassland is still controversy. Here, we explore the effects of different grazing intensities on plant biomass and species composition, both at community level and functional group level, and examines the productivity–species richness relationship under four grazing patterns: no grazing (CK), light grazing (LG), moderate grazing (MG) and heavy grazing (HG), attempt to determine a suitable grazing intensity in alpine grassland. The results were as follows. The total aboveground biomass (AGB) reduced with increasing grazing intensity, and the response of plant functional groups was different. AGB of both sedges and legumes increased from MG to HG, while the AGB of forbs reduced sharply and the grass AGB remained steady. There was a significant positive relationship between productivity and species richness both at community level and functional group level. In contrast, the belowground biomass (BGB) showed a unimodal relationship from CK to HG, peaking in MG (8297.72±621.29 g m-2). Interestingly, the grassland community tends to allocate more root biomass to the upper soil layer under increasing grazing intensities. Our results suggesting that moderate levels of disturbance may be the optimal grassland management strategy for alpine meadow in terms of root production