The effects of the environmental factors on Laminaria disease caused by alginic acid decomposing bacteria

-The rot disease of Laminaria occurs often in nurseries of sporeling and commercial cultivation in the sea and results in economic loss greatly. Usually the disease outbreaks accompanied with massive multiplication of alginic acid decomposing bacteria. From the section of the decaying Lamuutria which resulted from the inoculation of alginic acid decomposing bacteria, it was observed that the bacteria invaded the epiderm of the Laminaria surface at first, then entered the ex-odermis, endodermis and pith. In addition, there were a great amount of bacteria in the intercellular region and a lot of free cells of the algae in the decaying areas. The wall of some free cells was decomposed, which led to soft tissue or disintegration. Alginic acid decomposing bacteria are normal epiphytic microorganisms growing on Lamuutria surface. These bacteria do not cause disease at normal environmental conditions. The experiments showed that the unfavourable conditions, e. g. , wounding, overcrowding, high temperature reduced the ability of antibacterial activity and made the algae more susceptible to the pathogens and favoured the multiplication of alginic acid decomposing bacteria and finally led to the disease outbreak. The unfavourable environmental factors which resulted from a variety of reasons were the main cause of the disease.

Modeling and Analysis of Risk Propagation and Loss Causing Capacity for Key Nodes in Cyber-Physical Coupled Power Network

The modern power system has evolved into a cyber-physical system with deep coupling of physical and information domains,which brings new security risks.Aiming at the problem that the“information-physical”cross-domain attacks with key nodes as springboards seriously threaten the safe and stable operation of power grids,a risk propagation model considering key nodes of power communication coupling networks is proposed to study the risk propagation characteristics of malicious attacks on key nodes and the impact on the system.First,combined with the complex network theory,a topological model of the power communication coupling network is established,and the key nodes of the coupling network are screened out by Technique for Order Preference by Similarity to Ideal Solution(TOPSIS)method under the comprehensive evaluation index based on topological characteristics and physical characteristics.Second,a risk propagation model is established for malicious attacks on key nodes to study its propagation characteristics and analyze the state changes of each node in the coupled network.Then,two loss-causing factors:the minimum load loss ratio and transmission delay factor are constructed to quantify the impact of risk propagation on the coupled network.Finally,simulation analysis based on the IEEE 39-node system shows that the probability of node being breached(α)and the security tolerance of the system(β)are the key factors affecting the risk propagation characteristics of the coupled network,as well as the criticality of the node is positively correlated with the damage-causing factor.The proposed methodological model can provide an effective exploration of the diffusion of security risks in control systems on a macro level.

GIS-Based and Data-Driven Bivariate Landslide-Susceptibility Mapping in the Three Gorges Area, China

A detailed landslide-susceptibility map was produced using a data-driven objective bivariate analysis method with datasets developed for a geographic information system （GIS）. Known as one of the most landslide-prone areas in China, the Zhongxian-Shizhu Segment in the Three Gorges Reservoir region of China was selected as a suitable case because of the frequency and distribution of landslides. The site covered an area of 260.93 km^2 with a landslide area of 5.32 km^2. Four data domains were used in this study, including remote sensing products, thematic maps, geological maps, and topographical maps, all with 25 m × 25 m pixels. Statistical relationships for landslide susceptibility were developed using landslide and landslide causative factor databases. All continuous variables were converted to categorical variables according to the percentile divisions of seed cells, and the corresponding class weight values were calculated and summed to create the susceptibility map. According to the map, 3.6% of the study area was identified as high-susceptibility. Extremely low-, very low-, low-, and medium-susceptibility zones covered 19.66%, 31.69%, 27.95%, and 17.1% of the area, respectively. The high- and medium-hazardons zones are along both sides of the Yangtze River, being in agreement with the actual distribution of landslides.

Using a modified PAP/RAC model and GIS-for mapping water erosion and causal risk factors:Case study of the Asfalou watershed,Morocco

Our work focuses on the assessment of trends,erosion states and causal risk factors for soil erosion of the Asfalou watershed through the use of the Priority Actions Program/Regional Activity Center(PAP/RAC).This qualitative study model for water erosion makes it possible to assess susceptibility and determine potential fragile areas in order to diagnose the state of soil degradation.We adopted the PAP/RAC crossed matrices,the geographic information system(GIS)and remote sensing(RS)to develop the classical modelling.This method is based on three main approaches:predictive,descriptive and integration.Introducing soil types,slope length(LS)and climatic factors into our model,including rainfall erosivity(R),slope exposure,soil moisture index(SMI)and land surface temperature(LST),improved the reli-ability of our model.The correlation analysis identified these factors that explain erosion states and the risk of soil erosion.The coefficients of determination(R2)of the various erosive states resulting from the modified PAP/RAC approach explain respectively 98.30%,77%and 49.3%of the observed variability of the erosive states.These factors provide information on the current state of soil degradation depending on the degree of influence of the different factors that control erosion.The descriptive approach has shown that soil loss manifests itself in different forms,whether for sheet erosion(L)and ravines(C1)succes-sively affecting 79.95%and 17.84%of the land.The integration approach identifies factors and areas requiring intervention to counter the effects of soil erosion in the Asfalou watershed effectively and sustainably.

ACIDIC FIBROBLAST GROWTH FACTOR REDUCES RAT SKELETAL MUSCLE DAMAGE CAUSED BY ISCHEMIA AND REPERFUSION

Acute interruption of arterial blood flow to the extremities is often associated with significant morbidity and mortality. Broad spectrum mitogenic and non mitogenic activities of FGFs inspired us to study its protecting effects on tissue injuries in ischemia reperfusion condition. We found that systemic administration of aFGF after reperfusion onset prevented severe skeletal muscle injuries. In rats treated with aKGF, the tissue edema was reduced significantly, the tissue viability was increased, and the muscle fibers contained more succinate dehydrogenase (SDH) and adenosine triphosphatasc (ATPase). The pathological results supported the concept of improved prevention with aFGF treatment. The possible tissue protection by aFGF may come from its ability to regulate the concentration of evtra- and intracellular calcium ion. Besides, it may moderate other Ca2+ dependent enzyme conversion processes. Also, it may take part in the vascular tone regulation under ischemia and reperfusion conditions. These results suggest further study of tissue ischemia prevention with FGF and its possible mechanisms in the future.

Software defect prevention based on human error theories

Software defect prevention is an important way to reduce the defect introduction rate.As the primary cause of software defects,human error can be the key to understanding and preventing software defects.This paper proposes a defect prevention approach based on human error mechanisms：DPe HE.The approach includes both knowledge and regulation training in human error prevention.Knowledge training provides programmers with explicit knowledge on why programmers commit errors,what kinds of errors tend to be committed under different circumstances,and how these errors can be prevented.Regulation training further helps programmers to promote the awareness and ability to prevent human errors through practice.The practice is facilitated by a problem solving checklist and a root cause identification checklist.This paper provides a systematic framework that integrates knowledge across disciplines,e.g.,cognitive science,software psychology and software engineering to defend against human errors in software development.Furthermore,we applied this approach in an international company at CMM Level 5 and a software development institution at CMM Level 1 in the Chinese Aviation Industry.The application cases show that the approach is feasible and effective in promoting developers＇ ability to prevent software defects,independent of process maturity levels.