BACKGROUND In patients with schizophrenia,the brain structure and neurotransmitter levels change,which may be related to the occurrence and progression of this disease.AIM To explore the relationships between changes ...BACKGROUND In patients with schizophrenia,the brain structure and neurotransmitter levels change,which may be related to the occurrence and progression of this disease.AIM To explore the relationships between changes in neurotransmitters,brain structural characteristics,and the scores of the Positive and Negative Symptom Scale(PANSS)in patients with first-episode schizophrenia.METHODS The case group comprised 97 patients with schizophrenia,who were evaluated using the Canadian Neurological Scale and confirmed by laboratory tests at Ningbo Mental Hospital from January 2020 to July 2022.The control group comprised 100 healthy participants.For all participants,brain structural characteristics were explored by measuring brain dopamine(DA),glutamic acid(Glu),and gamma-aminobutyric acid(GABA)levels,with magnetic resonance imaging.The case group was divided into negative and positive symptom subgroups using PANSS scores for hierarchical analysis.Linear correlation analysis was used to analyze the correlations between neurotransmitters,brain structural character istics,and PANSS scores.RESULTS Patients in the case group had higher levels of DA and lower levels of Glu and GABA,greater vertical and horizontal distances between the corpus callosum and the inferior part of the fornix and larger ventricle area than patients in the control group(P<0.05).Patients with positive schizophrenia symptoms had significantly higher levels of DA,Glu,and GABA than those with negative symptoms(P<0.05).In patients with positive schizophrenia symptoms,PANSS score was significantly positively correlated with DA,vertical and horizontal distances between the corpus callosum and the infrafornix,and ventricular area,and was significantly negatively correlated with Glu and GABA(P<0.05).In patients with negative schizophrenia symptoms,PANSS score was significantly positively correlated with DA,vertical distance between the corpus callosum and the infrafornix,horizontal distance between the corpus callosum and the infrafornix,and ventricular area,and was significantly negatively correlated with Glu and GABA(P<0.05).CONCLUSION In patients with first-episode schizophrenia,DA levels increased,Glu and GABA levels decreased,the thickness of the corpus callosum increased,and these variables were correlated with PANSS scores.展开更多
The development of various applications based on social network text is in full swing.Studying text features and classifications is of great value to extract important information.This paper mainly introduces the comm...The development of various applications based on social network text is in full swing.Studying text features and classifications is of great value to extract important information.This paper mainly introduces the common feature selection algorithms and feature representation methods,and introduces the basic principles,advantages and disadvantages of SVM and KNN,and the evaluation indexes of classification algorithms.In the aspect of mutual information feature selection function,it describes its processing flow,shortcomings and optimization improvements.In view of its weakness in not balancing the positive and negative correlation characteristics,a balance weight attribute factor and feature difference factor are introduced to make up for its deficiency.The experimental stage mainly describes the specific process:the word segmentation processing,to disuse words,using various feature selection algorithms,including optimized mutual information,and weighted with TF-IDF.Under the two classification algorithms of SVM and KNN,we compare the merits and demerits of all the feature selection algorithms according to the evaluation index.Experiments show that the optimized mutual information feature selection has good performance and is better than KNN under the SVM classification algorithm.This experiment proves its validity.展开更多
In the north Indian Ocean (NIO), maps of sea level anomaly from satellite altimetry were analysed from January-1995 to December-2000. The study attempted to trace the trajectories of the individual mesoscale anomalies...In the north Indian Ocean (NIO), maps of sea level anomaly from satellite altimetry were analysed from January-1995 to December-2000. The study attempted to trace the trajectories of the individual mesoscale anomalies manually and to understand seasonal changes in terms of phase speed. Mesoscale anomalies are detected as concentric circular shapes and diameters of ~90 km to 600 km and the minimum 30 days life cycle. Relatively higher eddy kinetic energy was noticed in the northwestern region of the NIO. Individual mesoscale anomalies, namely positive (warm, anticyclonic eddies) and negative (cold, cyclonic eddies) showing travelling direction westward in the NIO basins. In autumn, the number of negative anomalies detected is more than positive anomalies and vice versa during summer. The westward propagating positive (negative) anomalies in the Arabian Sea start appearing in winter (spring) along (away from) the west coast of India and west of 65°E;individual anomalies move to the west in spring/summer/autumn and collide along Somalia’s & Arabian coast. A group of positive (negative) anomalies trajectories appears as a tail at the southern tip of India are located west of the Laccadive ridge in winter (summer to autumn) associated with LH (LL). The Bay of Bengal (BB) trajectories show southwestward in northern BB, westward in central BB and northwestward in southern BB;individual anomalies are appearing along the west coast of Andaman & Nicobar ridge. The zonal phase speed decreases away from the equator, and the magnitude varies longitudinally in each season in the form of a wave-like pattern propagating westward from autumn to summer;the life cycle of the wave is almost 365 days (a year). The theoretical phase speed of the first mode of the baroclinic Rossby waves is quite similar to that of averaged zonal speed. Therefore mesoscale anomalies (eddies) are embedded into the large waves like phenomenon (Rossby waves), responsible for creating high variability and EKE in the region of NIO along the western boundaries.展开更多
西格拉花岗岩体位于祁连东部的米屈花岗岩带上,空间上呈NW-NWW向展布,岩体由花岗闪长岩-花岗岩-正长岩组成,主要岩性为花岗闪长岩。LA-ICP-MS锆石U-Pb定年结果表明,西格拉花岗闪长岩存在两期岩浆作用,年龄分别为465.6±6.5Ma、443.2...西格拉花岗岩体位于祁连东部的米屈花岗岩带上,空间上呈NW-NWW向展布,岩体由花岗闪长岩-花岗岩-正长岩组成,主要岩性为花岗闪长岩。LA-ICP-MS锆石U-Pb定年结果表明,西格拉花岗闪长岩存在两期岩浆作用,年龄分别为465.6±6.5Ma、443.2±4.8Ma,其中,前者与祁连洋俯冲极性发生转变的时限（~463Ma）相近,而后者与祁连洋闭合的时间（~445Ma）相似。早期淡色花岗闪长岩具正铕异常（δEu=2.44）,晚期暗色花岗闪长岩则为弱负/正铕异常（δEu=0.94~1.32）,两者均显示出高Si、Al,富Na贫K,富集Ba、Sr、LREE,高Sr/Y值,低Y、HREE含量,亏损HFSE（Nb、Ta、Ti、P）的特征,与Martin et al.（2005）划分的高硅埃达克岩（HSA）相似。其源区可能均残留石榴子石、普通角闪石及少量金红石,而斜长石则大量参与部分熔融过程,推测早期花岗闪长岩的源区深度可能超过50km;整体上,由早期→晚期反映出加厚地壳减薄、地幔组分贡献增强的趋势;两者可能均为加厚下地壳物质部分熔融的产物。展开更多
Background:Ecological processes such as seedling establishment,biotic interactions,and mortality can leave footprints on species spatial structure that can be detectable through spatial point-pattern analysis(SPPA).Be...Background:Ecological processes such as seedling establishment,biotic interactions,and mortality can leave footprints on species spatial structure that can be detectable through spatial point-pattern analysis(SPPA).Being widely used in plant ecology,SPPA is increasingly carried out to describe biotic interactions and interpret patternprocess relationships.However,some aspects are still subjected to a non-negligible debate such as required sample size(in terms of the number of points and plot area),the link between the low number of points and frequently observed random(or independent)patterns,and relating patterns to processes.In this paper,an overview of SPPA is given based on rich and updated literature providing guidance for ecologists(especially beginners)on summary statistics,uni-/bi-/multivariate analysis,unmarked/marked analysis,types of marks,etc.Some ambiguities in SPPA are also discussed.Results:SPPA has a long history in plant ecology and is based on a large set of summary statistics aiming to describe species spatial patterns.Several mechanisms known to be responsible for species spatial patterns are actually investigated in different biomes and for different species.Natural processes,plant environmental conditions,and human intervention are interrelated and are key drivers of plant spatial distribution.In spite of being not recommended,small sample sizes are more common in SPPA.In some areas,periodic forest inventories and permanent plots are scarce although they are key tools for spatial data availability and plant dynamic monitoring.Conclusion:The spatial position of plants is an interesting source of information that helps to make hypotheses about processes responsible for plant spatial structures.Despite the continuous progress of SPPA,some ambiguities require further clarifications.展开更多
文摘BACKGROUND In patients with schizophrenia,the brain structure and neurotransmitter levels change,which may be related to the occurrence and progression of this disease.AIM To explore the relationships between changes in neurotransmitters,brain structural characteristics,and the scores of the Positive and Negative Symptom Scale(PANSS)in patients with first-episode schizophrenia.METHODS The case group comprised 97 patients with schizophrenia,who were evaluated using the Canadian Neurological Scale and confirmed by laboratory tests at Ningbo Mental Hospital from January 2020 to July 2022.The control group comprised 100 healthy participants.For all participants,brain structural characteristics were explored by measuring brain dopamine(DA),glutamic acid(Glu),and gamma-aminobutyric acid(GABA)levels,with magnetic resonance imaging.The case group was divided into negative and positive symptom subgroups using PANSS scores for hierarchical analysis.Linear correlation analysis was used to analyze the correlations between neurotransmitters,brain structural character istics,and PANSS scores.RESULTS Patients in the case group had higher levels of DA and lower levels of Glu and GABA,greater vertical and horizontal distances between the corpus callosum and the inferior part of the fornix and larger ventricle area than patients in the control group(P<0.05).Patients with positive schizophrenia symptoms had significantly higher levels of DA,Glu,and GABA than those with negative symptoms(P<0.05).In patients with positive schizophrenia symptoms,PANSS score was significantly positively correlated with DA,vertical and horizontal distances between the corpus callosum and the infrafornix,and ventricular area,and was significantly negatively correlated with Glu and GABA(P<0.05).In patients with negative schizophrenia symptoms,PANSS score was significantly positively correlated with DA,vertical distance between the corpus callosum and the infrafornix,horizontal distance between the corpus callosum and the infrafornix,and ventricular area,and was significantly negatively correlated with Glu and GABA(P<0.05).CONCLUSION In patients with first-episode schizophrenia,DA levels increased,Glu and GABA levels decreased,the thickness of the corpus callosum increased,and these variables were correlated with PANSS scores.
文摘The development of various applications based on social network text is in full swing.Studying text features and classifications is of great value to extract important information.This paper mainly introduces the common feature selection algorithms and feature representation methods,and introduces the basic principles,advantages and disadvantages of SVM and KNN,and the evaluation indexes of classification algorithms.In the aspect of mutual information feature selection function,it describes its processing flow,shortcomings and optimization improvements.In view of its weakness in not balancing the positive and negative correlation characteristics,a balance weight attribute factor and feature difference factor are introduced to make up for its deficiency.The experimental stage mainly describes the specific process:the word segmentation processing,to disuse words,using various feature selection algorithms,including optimized mutual information,and weighted with TF-IDF.Under the two classification algorithms of SVM and KNN,we compare the merits and demerits of all the feature selection algorithms according to the evaluation index.Experiments show that the optimized mutual information feature selection has good performance and is better than KNN under the SVM classification algorithm.This experiment proves its validity.
文摘In the north Indian Ocean (NIO), maps of sea level anomaly from satellite altimetry were analysed from January-1995 to December-2000. The study attempted to trace the trajectories of the individual mesoscale anomalies manually and to understand seasonal changes in terms of phase speed. Mesoscale anomalies are detected as concentric circular shapes and diameters of ~90 km to 600 km and the minimum 30 days life cycle. Relatively higher eddy kinetic energy was noticed in the northwestern region of the NIO. Individual mesoscale anomalies, namely positive (warm, anticyclonic eddies) and negative (cold, cyclonic eddies) showing travelling direction westward in the NIO basins. In autumn, the number of negative anomalies detected is more than positive anomalies and vice versa during summer. The westward propagating positive (negative) anomalies in the Arabian Sea start appearing in winter (spring) along (away from) the west coast of India and west of 65°E;individual anomalies move to the west in spring/summer/autumn and collide along Somalia’s & Arabian coast. A group of positive (negative) anomalies trajectories appears as a tail at the southern tip of India are located west of the Laccadive ridge in winter (summer to autumn) associated with LH (LL). The Bay of Bengal (BB) trajectories show southwestward in northern BB, westward in central BB and northwestward in southern BB;individual anomalies are appearing along the west coast of Andaman & Nicobar ridge. The zonal phase speed decreases away from the equator, and the magnitude varies longitudinally in each season in the form of a wave-like pattern propagating westward from autumn to summer;the life cycle of the wave is almost 365 days (a year). The theoretical phase speed of the first mode of the baroclinic Rossby waves is quite similar to that of averaged zonal speed. Therefore mesoscale anomalies (eddies) are embedded into the large waves like phenomenon (Rossby waves), responsible for creating high variability and EKE in the region of NIO along the western boundaries.
文摘西格拉花岗岩体位于祁连东部的米屈花岗岩带上,空间上呈NW-NWW向展布,岩体由花岗闪长岩-花岗岩-正长岩组成,主要岩性为花岗闪长岩。LA-ICP-MS锆石U-Pb定年结果表明,西格拉花岗闪长岩存在两期岩浆作用,年龄分别为465.6±6.5Ma、443.2±4.8Ma,其中,前者与祁连洋俯冲极性发生转变的时限（~463Ma）相近,而后者与祁连洋闭合的时间（~445Ma）相似。早期淡色花岗闪长岩具正铕异常（δEu=2.44）,晚期暗色花岗闪长岩则为弱负/正铕异常（δEu=0.94~1.32）,两者均显示出高Si、Al,富Na贫K,富集Ba、Sr、LREE,高Sr/Y值,低Y、HREE含量,亏损HFSE（Nb、Ta、Ti、P）的特征,与Martin et al.（2005）划分的高硅埃达克岩（HSA）相似。其源区可能均残留石榴子石、普通角闪石及少量金红石,而斜长石则大量参与部分熔融过程,推测早期花岗闪长岩的源区深度可能超过50km;整体上,由早期→晚期反映出加厚地壳减薄、地幔组分贡献增强的趋势;两者可能均为加厚下地壳物质部分熔融的产物。
文摘Background:Ecological processes such as seedling establishment,biotic interactions,and mortality can leave footprints on species spatial structure that can be detectable through spatial point-pattern analysis(SPPA).Being widely used in plant ecology,SPPA is increasingly carried out to describe biotic interactions and interpret patternprocess relationships.However,some aspects are still subjected to a non-negligible debate such as required sample size(in terms of the number of points and plot area),the link between the low number of points and frequently observed random(or independent)patterns,and relating patterns to processes.In this paper,an overview of SPPA is given based on rich and updated literature providing guidance for ecologists(especially beginners)on summary statistics,uni-/bi-/multivariate analysis,unmarked/marked analysis,types of marks,etc.Some ambiguities in SPPA are also discussed.Results:SPPA has a long history in plant ecology and is based on a large set of summary statistics aiming to describe species spatial patterns.Several mechanisms known to be responsible for species spatial patterns are actually investigated in different biomes and for different species.Natural processes,plant environmental conditions,and human intervention are interrelated and are key drivers of plant spatial distribution.In spite of being not recommended,small sample sizes are more common in SPPA.In some areas,periodic forest inventories and permanent plots are scarce although they are key tools for spatial data availability and plant dynamic monitoring.Conclusion:The spatial position of plants is an interesting source of information that helps to make hypotheses about processes responsible for plant spatial structures.Despite the continuous progress of SPPA,some ambiguities require further clarifications.
