Bionic Design of the Surface Morphology of Rubber Bush Covered on Driving Drums

Driving drum uses friction force to transfer power in belt conveyor. By means of bionic technology, the surface morphology of driving drum's flexible cladding was researched to increase the frictional traction force in this paper. Taking tree frog and katydid as biological prototypes, the structural features and adhesion mechanisms of their epidermal pad attachment organs were studied. Imitating the shape and structure of the epidermal pads, based on the principle of function bionics, four new surface morphologies of drum’s bush were designed. The behavior of the bionic bush contacting to the belt was simulated with finite element analysis software. The results of contact analysis show that the bionic drum’s bushes can generate embedding and interlocking effect during the contact process. The contact form can be changed from plane or cambered surface contact to meshing contact to enhance the frictional traction of drums. Keywords: Epidermal pad; Surface morphology; Bionic design; Finite element analysis; Frictio

Empirical analysis of the relationship between Supply Chain Management and business performance: Case of companies in the cotton sector in Mali.

As part of a national policy favoring the local processing of agricultural products, several companies have been created in the cotton sector in Mali. According to the 2014 report of the National Council of the Malian Patronage, several Malian companies have difficulties in terms of performance. The reasons for this insufficiency are: (difficult access to financing, poor management, poor quality of products, lack of information, etc.). We can summarize this situation by a lack of practices in Supply Chain Management. The objective of this section was to empirically evaluate the impact of supply chain management on the performance of companies operating in the cotton sector in Mali. We favored an approach that links four SCM practices across a variety of dimensions of performance. In our methodology, we used an econometric regression analysis. At the end of this study, it should be remembered that the practices of the management of the supplier relationship and the exchange and sharing of information constitute the two most productive supply chain management practices in the cotton sector in Mali. In addition, among the dimensions of performance considered, financial performance and customer satisfaction are the two most sensitive variants of SCM practices. Key words: the company, Performance, Supply Chain Management, information, customer, cotton sector

The Research of Biology Coupling Characteristics on the Shells of Haliotis discus hannai Ino

The surface morphologies, structures and materials of Haliotis discus hannai Ino shells were qualitatively studied by means of a stereoscopic microscope，a field emission scanning electronic microscopy, energy dispersive spectrometer and X-ray diffractometer, and abrasive particle wear was qualitatively and quantitatively studied by means of a pin-on-disc apparatus. The results showed that the outer layer surface of Haliotis discus hannai Ino shells was non-smooth and had some strumae or similar parallel convex wave. The shells of Haliotis discus hannai Ino are polycrystalline composites of calcium carbonate and proteins and glycoproteins and consist of the periostracum, prismatic and nacreous layers with calcite in the outer prismatic layer and aragonite in the inner nacreous layer. Nacreous layer is a natural composite comprised of calcium carbonate in the aragonite polymorph with organic macromolecules sandwiched in between, and the coupling of platelet interlocks and organic materials makes nacreous layer to be strong and tough.The abrasive particle wear tests showed that the abrasion resistance was different on the different parts of the shells, and the left of the shells possessed the highest abrasion resistance and the abrasion resistance of the shells was the lowest on the edge of the right. The nacreous layer possessed higher abrasion resistance than prismatic layer because of the coupling of structure and materials of nacreous layer. Key words: Haliotis discus hannai Ino shells; morphology; structure; materials; anti-wear; biological character; couplin

Salmonella produce microRNA-like RNA fragment Sal-1 in the infected cells to facilitate intracellular survival.

Salmonella have developed a sophisticated machinery to evade immune clearance and promote survival in the infected cells. Previous studies were mostly focused on either bacteria itself or host cells, the interaction mechanism of host-pathogen awaits further exploration. In the present study, we show that Salmonella can exploit mammalian cell non-classical microRNA processing machinery to further process bacterial small non-coding RNAs into microRNA-like fragments. Sal-1, one such fragment with the highest copy number in the infected cells, is derived from Salmonella 5-leader of the ribosomal RNA transcript and has a stem structure-containing precursor. Processing of Sal-1 precursors to mature Sal-1 is dependent on host cell Argonaute 2 (AGO2) but not Dicer. Functionally, depleting cellular Sal-1 strongly renders the Salmonella bacteria less resistant to the host defenses both in vitro and in vivo. In conclusion, we demonstrate a novel strategy for Salmonella evading the host immune clearance, in which Salmonella produce microRNA-like functional RNA fragments to establish a microenvironment facilitating bacterial survival

Transcriptional changes in Toxoplasma gondii in response to treatment with monensin

Background: Infection with the apicomplexan protozoan parasite T. gondii can cause severe and potentially fatal cerebral and ocular disease, especially in immunocompromised individuals. The anticoccidial ionophore drug monensin has been shown to have anti-Toxoplasma gondii properties. However, the comprehensive molecular mechanisms that underlie the effect of monensin on T. gondii are still largely unknown. We hypothesized that analysis of T. gondii transcriptional changes induced by monensin treatment can reveal new aspects of the mechanism of action of monensin against T. gondii. Methods: Porcine kidney (PK)-15 cells were infected with tachyzoites of T. gondii RH strain. Three hours post-infection, PK-15 cells were treated with 0.1 ?M monensin, while control cells were treated with medium only. PK-15 cells containing intracellular tachyzoites were harvested at 6 and 24 h post-treatment, and the transcriptomic profiles of T. gondii-infected PK-15 cells were examined using high-throughput RNA sequencing (RNA-seq). Quantitative real-time PCR was used to verify the expression of 15 differentially expressed genes (DEGs) identified by RNA-seq analysis. Results: A total of 4868 downregulated genes and three upregulated genes were identified in monensin-treated T. gondii, indicating that most of T. gondii genes were suppressed by monensin. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of T. gondii DEGs showed that T. gondii metabolic and cellular pathways were significantly downregulated. Spliceosome, ribosome, and protein processing in endoplasmic reticulum were the top three most significantly enriched pathways out of the 30 highly enriched pathways detected in T. gondii. This result suggests that monensin, via down-regulation of protein biosynthesis in T. gondii, can limit the parasite growth and proliferation. Conclusions: Our findings provide a comprehensive insight into T. gondii genes and pathways with altered expression following monensin treatment. These data can be further explored to achieve better understanding of the specific mechanism of action of monensin against T. gondii.[Figure not available: see fulltext.