Condensation of Eigen Microstate in Statistical Ensemble and Phase Transition

In a statistical ensemble with $M$ microstates, we introduce an $M \times M$ correlation matrix with the correlations between microstates as its elements. Using eigenvectors of the correlation matrix, we can define eigen microstates of the ensemble. The normalized eigenvalue by $M$ represents the weight factor in the ensemble of the corresponding eigen microstate. In the limit $M \to \infty$, weight factors go to zero in the ensemble without localization of microstate. The finite limit of weight factor when $M \to \infty$ indicates a condensation of the corresponding eigen microstate. This indicates a phase transition with new phase characterized by the condensed eigen microstate. We propose a finite-size scaling relation of weight factors near critical point, which can be used to identify the phase transition and its universality class of general complex systems. The condensation of eigen microstate and the finite-size scaling relation of weight factors have been confirmed by the Monte Carlo data of one-dimensional and two-dimensional Ising models.Comment: 9 pages, 16 figures, accepted for publication in Sci. China-Phys. Mech. Astro

studyoftheshearratedependenceofgranularfrictionbasedoncommunitydetection

In this study, computer simulations are performed on three-dimensional granular systems under shear conditions. The system comprises granular particles that are confined between two rigid plates. The top plate is subjected to a normal force and driven by a shearing velocity. A positive shear-rate dependence of granular friction, known as velocity-strengthening, exists between the granular and shearing plate. To understand the origin of the dependence of frictional sliding, we treat the granular system as a complex network, where granular particles are nodes and normal contact forces are weighted edges used to obtain insight into the interiors of granular matter. Community structures within granular property networks are detected under different shearing velocities in the steady state. Community parameters, such as the size of the largest cluster and average size of clusters, show significant monotonous trends in shearing velocity associated with the shear-rate dependence of granular friction. Then, we apply an instantaneous change in shearing velocity. A dramatic increase in friction is observed with a change in shearing velocity in the non-steady state. The community structures in the non-steady state are different from those in the steady state. Results indicate that the largest cluster is a key factor affecting the friction between the granular and shearing plate

A Identidade do Ensino Superior: a Educação Superior e a Universidade

A definição de uma ‘ideia' de educação superior parece ser uma tarefa que alguns pós-modernistas lançam definitivamente para o caixote do lixo da história. Produto, por excelência, da modernidade, e no cruzamento dos modelos humboldtiano, napoleónico e de Oxbridge, a educação superior, tal como a herdámos, era centrada no conhecimento, isto é, na sua produção (investigação), na sua distribuição (ensino) e na sua difusão pelo corpo social (função de serviço à sociedade). O conhecimento e o seu manuseamento definiam não só a missão institucional como a natureza das organizações consagradas ao ensino superior. A estes elementos componentes da ‘ideia' de educação superior foram incorporados outros igualmente estruturantes: a funcionalidade destas instituições em relação à consolidação e desenvolvimento do Estado-nação. Os quadros necessários ao funcionamento e estrutura do aparelho de Estado encontravam nas universidades e noutros institutos de ensino superior o lugar privilegiado para a sua formação. O que este artigo pretende argumentar é que, num contexto em que a produção, a distribuição e a difusão do conhecimento se transformam, em que a globalização/localização intensifica - sobretudo na Europa - a fragilidade das instâncias nacionais e em que o processo de massificação e de democratização do acesso ao ensino superior o conduzem a outro modelo sociológico que não o de origem, a educação superior está a viver uma identidade esquizóide: educação terciária, pós-secundária, educação fundada na investigação, educação vocacional, etc. Esta situação requer um esforço de reflexividade que, ao mesmo tempo que recusa a procura essencialista de uma ‘ideia' de ensino superior, enfatiza a necessidade de promover uma perspectiva de educação que não soçobre ao pobre paradigma da adaptabilidade, segundo o qual o critério de utilidade de uma dada instituição é directamente proporcional à sua capacidade de sobreviver às mudanças operadas no seu ambiente organizacional.Palavras-chave: Ensino Superior; modernidade; identidade

Condensation of eigen microstate in statistical ensemble and phase transition

In a statistical ensemble with M microstates, we introduce an MxM correlation matrix with correlations among microstates as its elements. Eigen microstates of ensemble can be defined using eigenvectors of the correlation matrix. The eigenvalue normalized by M represents weight factor in the ensemble of the corresponding eigen microstate. In the limit M , weight factors drop to zero in the ensemble without localization of the microstate. The finite limit of the weight factor when M indicates a condensation of the corresponding eigen microstate. This finding indicates a transition into a new phase characterized by the condensed eigen microstate. We propose a finite-size scaling relation of weight factors near critical point, which can be used to identify the phase transition and its universality class of general complex systems. The condensation of eigen microstate and the finite-size scaling relation of weight factors are confirmed using Monte Carlo data of one-dimensional and two-dimensional Ising models.</p

Distinct patterns of distribution, community assembly and cross-domain co-occurrence of planktonic archaea in four major estuaries of China

Abstract Background Archaea are key mediators of estuarine biogeochemical cycles, but comprehensive studies comparing archaeal communities among multiple estuaries with unified experimental protocols during the same sampling periods are scarce. Here, we investigated the distribution, community assembly, and cross-domain microbial co-occurrence of archaea in surface waters across four major estuaries (Yellow River, Yangtze River, Qiantang River, and Pearl River) of China cross climatic zones (~ 1,800 km) during the winter and summer cruises. Results The relative abundance of archaea in the prokaryotic community and archaeal community composition varied with estuaries, seasons, and stations (reflecting local environmental changes such as salinity). Archaeal communities in four estuaries were overall predominated by ammonia-oxidizing archaea (AOA) (aka. Marine Group (MG) I; primarily Nitrosopumilus), while the genus Poseidonia of Poseidoniales (aka. MGII) was occasionally predominant in Pearl River estuary. The cross-estuary dispersal of archaea was largely limited and the assembly mechanism of archaea varied with estuaries in the winter cruise, while selection governed archaeal assembly in all estuaries in the summer cruise. Although the majority of archaea taxa in microbial networks were peripherals and/or connectors, extensive and distinct cross-domain associations of archaea with bacteria were found across the estuaries, with AOA as the most crucial archaeal group. Furthermore, the expanded associations of MGII taxa with heterotrophic bacteria were observed, speculatively indicating the endogenous demand for co-processing high amount and diversity of organic matters in the estuarine ecosystem highly impacted by terrestrial/anthropogenic input, which is worthy of further study. Conclusions Our results highlight the lack of common patterns in the dynamics of estuarine archaeal communities along the geographic gradient, expanding the understanding of roles of archaea in microbial networks of this highly dynamic ecosystem

Comparative transcriptome analysis of sweet corn seedlings under low-temperature stress

Stress induced by low temperature, which represents a widespread environmental factor, strongly affects maize growth and yield. However, the physiological characteristics and molecular regulatory mechanisms of maize seedlings in response to cold remain poorly understood. In this study, using RNA-seq, we investigated the transcriptome profiles of two sweet corn inbred lines, “Richao” (RC) and C5, under cold stress. A total of 357 and 455 differentially expressed genes (DEGs) were identified in the RC and C5 lines, respectively, 94 DEGs were detected as common DEGs related to cold response in both genotypes, and a total of 589 DEGs were detected as cold tolerance-associated genes. By combining protein function clustering analysis and significantly enriched Gene Ontology (GO) terms analysis, we suggest that transcription factors may play a dominating role in the cold stress response and tolerance of sweet corn. Furthermore, 74 differentially expressed transcription factors were identified, of those many genes involved in the metabolism and regulation of hormones. These results expand our understanding of the complex mechanisms involved in chilling tolerance in maize, and provide a set of candidate genes for further genetic analyses

An exploratory clinical trial of apatinib combined with intensity‐modulated radiation therapy for patients with unresectable hepatocellular carcinoma

Abstract Purpose To evaluate the clinical efficacy and safety of apatinib combined with intensity‐modulated radiation therapy (IMRT) in patients with unresectable hepatocellular carcinoma (uHCC). Materials and methods Open‐label, single‐arm, exploratory clinical trial of apatinib combined with IMRT for uHCC patients. Patients aged 18–75 years with adequate hematological, liver, and renal functions and Eastern Cooperative Oncology Group (ECOG) performance status of ≤2 were enrolled in this study from March 2017 to September 2020. Patients were received IMRT (biological effective dose: 46–60 Gy) and continuous apatinib (250–500 mg/day) oral administration until HCC progression or unacceptable toxic effects. The endpoints included progression‐free survival (PFS), overall survival (OS), disease control rate (DCR), objective response rate (ORR), and safety. The trial registration number is ChiCTR‐OPC‐17011890. Results A total of 33 patients have taken part in the study. The median age was 58 years old (range 32–77), 27 (81.9%) patients were ECOG PS 0–1, and 28 (84.9%) patients were male. In addition, 25 (75.7%) patients suffered from hepatitis B, 32 cases (97.0%) were in Barcelona Clinic Liver Cancer (BCLC) Stages B–C, and eight (24.2%) had portal vein involvement. Moreover, 12 (36.4%) and 21 (63.6%) patients received apatinib as first‐line and second or later‐line therapy, respectively. The average follow‐up was 11.4 months, the median PFS was 7.8 months (95% confidence interval: 3.9–11.7). The OS rates at 6 and 12 months were 96.7% and 66.2%. The ORR and DCR were 15.1% and 81.8%, respectively. Hepatic toxicity was the most common treatment‐related adverse events in Grades 3–4 (12.1%). No radiation‐induced liver disease and Grade 5 toxicity were recorded. Conclusion Apatinib combined with IMRT is a safe and effective method to improve PFS and DCR and has good anti‐tumor activity in patients with uHCC

Microstructures and photosynthetic diurnal changes in the different types of lichen soil crusts

In the revegetation region of Shapotou (at the southeastern edge of Tengger Desert), biological soil crusts (BSCs) generally develop and succeed from cyanobacterial soil crusts (CSCs) to lichen soil crusts (LSCs). Based on the different dominant lichens on crust surface, LSCs were further divided into cyanolichen soil crusts (CLSCs) and green algae lichen soil crusts (GLSCs). In this study, the microstructures and photosynthetic diurnal changes in both CLSCs and GLSCs were investigated using the microscopic observation and chlorophyll fluorescence techniques. The results showed the different types of LSCs have different surface morphological characteristics and inner structures due to the different biological compositions. Compared with the CLSCs, GLSCs had a higher photosynthetic efficiency, including the maximum photosynthetic efficiency (Fv/Fm) and effective photosynthetic efficiency (Phi(PSII)), which in the final analysis was considered to be closely correlated with the different photosynthetic characteristics between different photobiont types (green algae and cyanobacteria). In addition, similar to CSCs, a midday depression of photosynthetic efficiency was detected in LSCs, although the depression extents were different in different types of LSCs. In conclusion, the occurrence of midday depression of photosynthetic efficiency might be a stress effect and also an adaptation strategy of LSCs to adversity, especially the high light intensity and temperature at noon. (C) 2013 Elsevier Masson SAS. All rights reserved.In the revegetation region of Shapotou (at the southeastern edge of Tengger Desert), biological soil crusts (BSCs) generally develop and succeed from cyanobacterial soil crusts (CSCs) to lichen soil crusts (LSCs). Based on the different dominant lichens on crust surface, LSCs were further divided into cyanolichen soil crusts (CLSCs) and green algae lichen soil crusts (GLSCs). In this study, the microstructures and photosynthetic diurnal changes in both CLSCs and GLSCs were investigated using the microscopic observation and chlorophyll fluorescence techniques. The results showed the different types of LSCs have different surface morphological characteristics and inner structures due to the different biological compositions. Compared with the CLSCs, GLSCs had a higher photosynthetic efficiency, including the maximum photosynthetic efficiency (Fv/Fm) and effective photosynthetic efficiency (Phi(PSII)), which in the final analysis was considered to be closely correlated with the different photosynthetic characteristics between different photobiont types (green algae and cyanobacteria). In addition, similar to CSCs, a midday depression of photosynthetic efficiency was detected in LSCs, although the depression extents were different in different types of LSCs. In conclusion, the occurrence of midday depression of photosynthetic efficiency might be a stress effect and also an adaptation strategy of LSCs to adversity, especially the high light intensity and temperature at noon. (C) 2013 Elsevier Masson SAS. All rights reserved