Identifying influential nodes in complex contagion mechanism

Identifying influential nodes in complex networks is one of the most important and challenging problems to help optimize the network structure, control the spread of the epidemic and accelerate the spread of information. In a complex network, the node with the strongest propagation capacity is known as the most influential node from the perspective of propagation. In recent years, identifying the key nodes in complex networks has received increasing attention. However, it is still a challenge to design a metric that has low computational complexity but can accurately identify important network nodes. Currently, many centrality metrics used to evaluate the influence capability of nodes cannot balance between high accuracy and low time complexity. Local centrality suffers from accuracy problems, while global metrics require higher time complexity, which is inefficient for large scale networks. In contrast, semi-local metrics are with higher accuracy and lower time cost. In this paper, we propose a new semi-local centrality measure for identifying influential nodes under complex contagion mechanisms. It uses the higher-order structure within the first and second-order neighborhoods of nodes to define the importance of nodes with near linear time complexity, which can be applied to large-scale networks. To verify the accuracy of the proposed metric, we simulated the disease propagation process in four real and two artificial networks using the SI model under complex propagation. The simulation results show that the proposed method can identify the nodes with the strongest propagation ability more effectively and accurately than other current node importance metrics

The interactive effect of genetic polymorphisms of IL-10 and COMT on cognitive function in schizophrenia

Dopaminergic and inflammatory systems have been proven to play an important role in the cognitive deficits of schizophrenia. Although increasing evidence indicates two systems have strong interaction, the relevant research on this interaction is still limited. Catechol-o-methyltransferase (COMT) and Interleukin-10 (IL-10) play critical functions in dopaminergic and inflammatory systems respectively, and their genetic polymorphisms are both associated with cognitive function. However, the interactive effect of their genetic polymorphisms has not been investigated. In this study, COMT Val158Met (rs4680) and IL-10 -592A/C (rs1800872) polymorphisms were measured in patients with chronic schizophrenia (n = 244) and healthy controls (n = 396), and their cognitive functions were assessed using the ?Repeatable Battery for the Assessment of Neuropsychological Status? (RBANS). We found that IL-10 alone had no effect on cognitive function, while COMT affected language ability and interacted with the schizophrenia (case vs control) or sex in multiple RBANS indexes. Additionally, we found there was a significant interactive effect between IL-10 and COMT polymorphisms on multiple cognitive indexes of RBANS. In detail, the analysis showed that the IL-10 polymorphism had opposite effects on cognitive function in different COMT genotype carriers; meanwhile, the polymorphism of COMT only had a significant effect on cognitive function in IL-10 C carriers. And this interaction was more significant in schizophrenia than in controls. Our study discovered for the first time, there is an interactive effect between IL-10 and COMT genetic polymorphisms on cognitive function, which is valuable for further investigations and drug administrations associated with both systems.</p

Effects of Long-term Diving Training on Cortical Gyrification

During human brain development, cortical gyrification, which is believed to facilitate compact wiring of neural circuits, has been shown to follow an inverted U-shaped curve, coinciding with the two-stage neurodevelopmental process of initial synaptic overproduction with subsequent pruning. This trajectory allows postnatal experiences to refine the wiring, which may manifest as endophenotypic changes in cortical gyrification. Diving experts, typical elite athletes who commence intensive motor training at a very young age in their early childhood, serve ideal models for examining the gyrification changes related to long-term intensive diving training. Using local gyrification index (LGI), we compared the cortical gyrification between 12 diving experts and 12 controls. Compared with controls, diving experts showed widespread LGI reductions in regions relevant to diving performance. Negative correlations between LGIs and years of diving training were also observed in diving experts. Further exploratory network efficiency analysis of structural cortical networks, inferred from interregional correlation of LGIs, revealed comparable global and local efficiency in diving experts relative to controls. These findings suggest that gyrification reductions in diving experts may be the result of long-term diving training which could refine the neural circuitry (via synaptic pruning) and might be the anatomical substrate underlying their extraordinary diving performance.</p

P50 inhibition defects with psychopathology and cognitive impairment in patients with first-episode drug naive schizophrenia

Background: Many studies have announced that P50 inhibition defects represent sensory gating deficits in schizophrenia, but studies seldom have searched the correlation between P50 inhibition defects and the psychopathology or cognitive impairment of patients with first-episode, drug naive (FEDN) of schizophrenia. In this study, we investigated the auditory sensory gating deficits in a large number of Han patients with FEDN schizophrenia and their correlation with clinical symptoms and cognitive impairment. Methods: A total of 130 patients with FEDN schizophrenia and 189 healthy controls were recruited in this study. Positive and Negative Syndrome Scale (PANSS) and its five-factor model were used to score the psychopathology of the patients, and P50 inhibition was recorded using the 64-channel electroencephalography (EEG) system. Results: Patients exhibited significantly longer S1 and S2 latency, lower S1 and S2 amplitudes and lower P50 difference than healthy controls (all p &lt; 0.05). Significant correlations existed between S1 latency and PANSS negative symptoms or cognitive factor, P50 ratio and general psychopathology, P50 ratio and PANSS total score, P50 difference and general psychopathology, and P50 difference and PANSS total score (all p &lt; 0.05). Multiple regression analysis revealed that S1 latency, sex, age, and education were contributors to negative symptom score (all p &lt; 0.05). S1 latency, S2 latency, sex, age, and smoking status were contributors to cognitive factor (all p &lt; 0.05). Conclusions: Our results show that patients with FEDN schizophrenia have P50 inhibition defects, which may be related to their psychopathological symptoms and cognitive impairment.</p

Prevalence of obesity and clinical and metabolic correlates in first-episode schizophrenia relative to healthy controls

Objective People with schizophrenia exhibit a high obesity rate. However, little is known about the prevalence of obesity and its relationship with clinical symptoms and metabolic indicators in first-episode drug-naive (FEDN) schizophrenia. Methods Demographic and lipid parameters were gathered from 297 FEDN schizophrenia and 325 healthy controls. The patients' symptomatology was evaluated by the Positive and Negative Syndrome Scale (PANSS). Results The obesity rate of FEDN patients was 10.77%, similar to that of controls (10.5%). The prevalence of overweight plus obesity of patients was 44.8%, significantly higher than that of controls (36.6%). Compared with non-obese patients, obese patients had higher levels of cholesterol (4.81 +/- 0.93 vs 4.22 +/- 1.00 mmol/L), triglyceride (0.27 +/- 0.21 vs 0.14 +/- 0.24 mg/dL), low-density lipoprotein (0.48 +/- 0.12 vs 0.40 +/- 0.12 mg/dL), greater ratio of triglyceride/high-density lipoprotein (2.01 +/- 1.23 vs 1.44 +/- 1.26), and higher PANSS positive symptom subscale score (29.81 +/- 6.29 vs 27.05 +/- 6.15), general psychopathology subscale score (70.75 +/- 11.74 vs 66.87 +/- 11.37), and total score (149.81 +/- 21.08 vs 140.64 +/- 21.58), but lower high-density lipoprotein level (1.09 +/- 0.21 vs 1.27 +/- 0.34 mg/dL) (all p < 0.05). Correlation analysis revealed that body mass index (BMI) was positively correlated with triglyceride, cholesterol, high-density lipoprotein, low-density lipoprotein, triglyceride/high-density lipoprotein ratio, PANSS positive symptoms, general psychopathology, and total scores (all p < 0.05, r = 0.124 similar to 0.335). Multiple regression analysis confirmed that PANSS positive symptoms, total score, and cholesterol level were significantly associated with BMI (all p < 0.05, beta: 0.126-0.162). Conclusion There was no significant difference in the prevalence of obesity between FEDN patients and the control group. Moreover, BMI was positively associated with positive symptom severity in FEDN patients

Association of negative symptoms with cognitive impairment in Chinese Han patients with chronic schizophrenia

Objective Cognitive impairment is an essential feature of schizophrenia; however, the relationship between clinical psychiatric symptoms with cognitive impairment is still unclear. Therefore, we aimed to assess cognitive deficits and the relationship between clinical symptoms and cognitive function in patients with chronic schizophrenia, which provide a reference guide for psychiatrists. Methods We compared the cognitive function in 312 schizophrenia inpatients and 397 healthy controls by using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The positive and negative symptom scale (PANSS) was used to assess the clinical symptoms of the patients. Results Analysis of covariance showed that the RBANS total and four index scores (all p < 0.001) were significantly lower in patients than healthy controls. After Bonferroni correction, Pearson correlation analysis showed that there was a significant negative association between PANSS negative symptom subscale and RBANS total score and all 5 domain scores (all p < 0.01). Further regression analysis showed that negative symptoms, age, age of onset, and antipsychotic dose were important independent predictors of cognitive deficits. Conclusions Our findings suggest that patients with chronic schizophrenia exhibit cognitive deficits compared with healthy people. Negative symptoms and some clinical variables are associated with cognitive impairment in patients with schizophrenia. KEYPOINTS This study indicates that patients with chronic schizophrenia have extensive cognitive impairment shown on RBANS except for the visuospatial/constructional domain. Cognitive impairment in patients is associated with age, negative symptoms, age of onset, and antipsychotic dose. There is a significant negative association between cognitive deficits and negative symptoms in patients with chronic schizophrenia. The results of this study need to be confirmed in future studies with longitudinal designs with a large and sex-balanced sample in first-episode drug naive patients with schizophrenia

The combined impact of historical climate change and human activities on reservoir flood control risk

Study area: The Chengbi River Basin (CRB,106°21′ ∼106°48′ E, 23°50′ ∼24°45′ N) and the Chengbi River Reservoir (CRR) in Southwest China. Study focus: To quantitatively assess the combined impact of historical climate change and human activities (HCCHA) on flood control risk (FCR), this study proposes a framework including a characteristics analysis of the HCCHA, a more reasonable determining of the benchmark period and the influence period, and an evaluation of the combined impact of the HCCHA on the flood control risk with bi-variate flood frequency analysis. New hydrological insights for the region: Findings show that: (i) The annual rainfall (44.342 mm/10a) and annual average temperature (0.5796 ℃/10a) increased significantly, while the potential evaporation decreased(‐44.342decreased(−44.342 mm/10a). In the land use change that characterizes human activities, woodland and cropland showed upward trends while a decreasing trend in grassland. (ii) The starting time of climate change (1985) in the CRB is earlier than that of human activities (1988), thus the demarcation time of the benchmark period and influence period is 1985. (iii)As for bivariate flood frequency analysis, the G-H Copula function outperformed the other Copula functions with the error ranges of −0.1654 to 0.0965. (iv) Influenced by HCCHA, the FCR under the design condition decreased by 0.11211–0.05419%, and the corresponding flood control standard (FCS) increased from 892a to 1845a

Association of cigarette smoking with cognitive impairment in male patients with chronic schizophrenia

Background Previous studies have shown that patients with schizophrenia have higher smoking rates and worse cognitive function than healthy controls. However, there is no consistent conclusion about the relationship between smoking and cognitive impairment. Objectives The main purpose of this study was to explore the effects of smoking on cognitive function by using MATRICS Cognitive Consensus Battery (MCCB) in Chinese male patients with schizophrenia. Methods There were 164 patients with chronic schizophrenia and 82 healthy controls. All subjects were interviewed about smoking status. The cognitive function was assessed by MCCB and Stroop tests. The Positive and Negative Syndrome Scale (PANSS) was used to assess the clinical symptoms of the patients. Results Compared with healthy controls, patients had lower MCCB scores in all of its domain scores (allp&lt; 0.05). In the patients, the scores of spatial span test (42.3 +/- 11.6), digital sequence test (42.9 +/- 10.6), and Hopkins Verbal Learning Test (42.2 +/- 10.1) were lower in smokers than those in nonsmokers (allp&lt; 0.05, effect size: 0.28-0.45). Logistic regression analysis showed that the smoking status of the patients was correlated with digital sequence score (p&lt; 0.05, OR = 1.072, 95%CI: 1.013-1.134). Multivariate regression analysis showed that the spatial span total score (beta= - 0.26,t= - 2.74,p&lt; 0.001) was associated with the duration of smoking in patients with schizophrenia. Conclusions Our findings show that smoking patients with chronic schizophrenia exhibit more severe cognitive impairment than nonsmoking patients, especially in working memory and executive function.</p

One-day tropisetron treatment improves cognitive deficits and P50 inhibition deficits in schizophrenia

The core features of schizophrenia (SCZ) include cognitive deficits and impaired sensory gating represented by P50 inhibition deficits, which appear to be related to the alpha 7 nicotinic acetylcholine receptor (nAChR). An agonist of nAChR receptor may improve these defects. This study aimed to investigate how administering multiple doses of tropisetron, a partial agonist of nAChR, for 1 day would affect cognitive deficits and P50 inhibition deficits in SCZ patients. We randomized 40 SCZ non-smokers into a double-blind clinical trial with four groups: placebo, 5 mg/d, 10 mg/d, and 20 mg/d of oral tropisetron. Their P50 ratios were all more than 0.5 and they took risperidone at 3-6 mg/day for at least a month before participating in the experiment. We measured the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and P50 inhibition before and one day after treatment. After one day of treatment, the total RBANS scores of the 20 mg and 5 mg tropisetron groups, and the immediate memory of the 10 mg group were significantly higher than placebo group. The P50 ratio was smaller in the 5 mg and 10 mg groups than in the placebo group (both p < 0.05) after treatment. Furthermore, the improvement in RBANS total score was correlated with increased S1 latency (p < 0.05), and the increase in immediate memory score was correlated with decreased S2 amplitude. One day of treatment with tropisetron improved both cognitive and P50 inhibition deficits, suggesting that longer term treatment with alpha 7 nAChR agonists for these deficits in SCZ may be promising