Mvmotion: a metadata based virtual machine migration in cloud

As one of the most important features of virtualization, virtual machine (VM) migration provides great benefits for load balancing, resources-saving, fault tolerance in modern cloud data centers. Considering the network traffic caused by transferring data during VM migration imposes a huge pressure on network bandwidth of cloud data centers, and by analyzing the characteristic of the transferred data, we found that the redundant data, which is produced between two physical hosts by hosting virtual machines cloned from same VM template, can be reduced to relieve the network traffic pressure. This paper presents a Metadata based VM migration approach (Mvmotion) to reduce the amount of transferred data during migration by utilizing memory de-redundant technique between two physical hosts. Mvmotion utilizes the hash based fingerprints to generate Metadata of memory, which is used to identify redundant memory of VMs between two hosts. Based on the Metadata, the transfer of redundant memory data during migration can be eliminated. Experiment demonstrates that, compare to Xen’s default migration approach, Mvmotion can reduce the total transferred data by 29–97 %, and decreases the migration time by 16–53 %.     

Putting plant resistance traits on the map: a test of the idea that plants are better defended at lower latitudes

? It has long been believed that plant species from the tropics have higher levels of traits associated with resistance to herbivores than do species from higher latitudes. A meta-analysis recently showed that the published literature does not support this theory. However, the idea has never been tested using data gathered with consistent methods from a wide range of latitudes. ? We quantified the relationship between latitude and a broad range of chemical and physical traits across 301 species from 75 sites world-wide. ? Six putative resistance traits, including tannins, the concentration of lipids (an indicator of oils, waxes and resins), and leaf toughness were greater in high-latitude species. Six traits, including cyanide production and the presence of spines, were unrelated to latitude. Only ash content (an indicator of inorganic substances such as calcium oxalates and phytoliths) and the properties of species with delayed greening were higher in the tropics. ? Our results do not support the hypothesis that tropical plants have higher levels of resistance traits than do plants from higher latitudes. If anything, plants have higher resistance toward the poles. The greater resistance traits of high-latitude species might be explained by the greater cost of losing a given amount of leaf tissue in low-productivity environments.     

Cloning and characterization of three novel WSSV recognizing lectins from shrimp Marsupenaeus japonicus

C-type lectins (CTLs) acting as pattern recognition receptors play essential roles in shrimp innate immune responses. Using WSSV envelope proteins (VP26, VP28, and VP281) to screen a phage display library of Marsupenaeus japonicus, three lectins (termed as MjLecA, MjLecB, and MjLecC) were found to interact with WSSV. Sequence analysis revealed that these MjLecs shared low similarities with each other. Phylogenetic analysis indicated MjLecA and MjLecB are likely to belong to the same lectin sub-family, while MjLecC belongs to another sub-family. These MjLecs showed broad, unique carbohydrate binding spectra. Also, the three MjLecs could interact with several envelope proteins of WSSV and could recognize a wide range of microorganisms. Moreover, binding of MjLecA or MjLecB to WSSV reduced the viral infection rate in vitro. These results suggest that various kinds of CTLs with structural and functional diversities may constitute a recognizing network against invading pathogens such as bacteria and virus, and play essential roles in the defence system of shrimp.     

Microbacterium marinum sp. nov., isolated from deep-sea water

Two Gram-positive, rod-shaped bacterial strains, H101(T) and H207, were isolated from deep sea water collected from South-West Indian Ocean. Phylogenetic analysis of 16S rRNA gene sequences showed that the two strains were closely related to one another (100% similarity), and had the closest relationship with Microbacterium hominis NBRC 15708(T) and Microbacterium insulae KCTC 19247(T) (98.2-98.3% similarities). DNA-DNA hybridization value between strains H101(T) and H207 was 87.2 ± 3.7%, and the values between the two strains and the closely related type strains were well below 70%. The two strains also shared a number of physiological and biochemical characteristics that were distinct from the closely related species, and grew at 2-37 ° C, pH 5-11 and 0-8% (w/v) NaCl. Both strains contained MK-12, MK-13 and MK-11 as the detected menaquinones. The peptidoglycan was of type B1γ with an interpeptide bridge D-Glu(Hyg)→ Gly(2)→ l-Lys. The major cellular fatty acids were anteiso-C(15:0), anteiso-C(17:0), and iso-C(16:0). Based on the genetic and phenotypic properties, it is proposed that strains H101(T) and H207 be classified as representatives of a novel species of the genus Microbacterium, with the name Microbacterium marinum sp. nov. The type strain is H101(T) (= CGMCC 4.6941(T) = DSM 24947(T)).     

Microcalorimetric studies on the polyhydroxyalkanoates production of recombinant Escherichia Coli

The thermogenic curves of metabolism of two strains of Escherichia coli pUC19cab/XL-IBlue and XL-IBlue have been determined by using a LKB-2277 bioActivity Monitor and ampoule method at 37°C. pUC19cab/XL-IBlue was a recombinant E. coli strain bearing a foreign plasmid pUC19cab which brought the polyhydroxyalkanoates (PHAs) production. XL-IBlue was a host bacterium without any foreign DNA. Our studies reveal that the PHA production of recombinant E. coli has an apparent influence on their thermogenic curves of metabolism and therefore the initial time of PHAs production can be determined from these thermogenic curves. The text was submitted by the authors in English.     

Subtyping animal influenza virus with general multiplex RT-PCR and Liquichip high throughput (GMPLex)

This study developed a multiplex RT-PCR integrated with luminex technology to rapidly subtype simultaneously multiple influenza viruses. Primers and probes were designed to amplify NS and M genes of influenza A viruses HA gene of H1, H3, H5, H7, H9 subtypes, and NA gene of the N1 and N2 subtypes. Universal super primers were introduced to establish a multiplex RT-PCR (GM RT-PCR). It included three stages of RT-PCR amplification, and then the RT-PCR products were further tested by LiquiChip probe, combined to give an influenza virus (IV) rapid high throughput subtyping test, designated as GMPLex. The IV GMPLex rapid high throughput subtyping test presents the following features: high throughput, able to determine the subtypes of 9 target genes in H1, H3, H5, H7, H9, N1, and N2 subtypes of the influenza A virus at one time; rapid, completing the influenza subtyping within 6 hours; high specificity, ensured the specificity of the different subtypes by using two nested degenerate primers and one probe, no cross reaction occurring between the subtypes, no non-specific reactions with other pathogens and high sensitivity. When used separately to detect the product of single GM RT-PCR for single H5 or N1 gene, the GMPLex test showed a sensitivity of 10⁻⁵(= 280ELD₅₀) forboth tests and the Luminex qualitative ratio results were 3.08 and 3.12, respectively. When used to detect the product of GM RT-PCR for H5N1 strain at the same time, both showed a sensitivity of 10⁻⁴(=2800 ELD₅₀). The GMPLex rapid high throughput subtyping test can satisfy the needs of influenza rapid testing.Key words: Influenza Virus, General multiplex RT-PCR, Iuminex assay, Subtyping, HA and NA genes     

PAK1 is a novel MEK-independent raf target controlling expression of the IAP survivin in M-CSF-mediated osteoclast survival

As activation of the Ras/Raf/MEK/ERK pathway is a critical component of M-CSF-promoted osteoclast survival, determining specific mechanism by which M-CSF activates this signal transduction pathway is paramount towards advancing treatment of pathological conditions resulting in increased bone turnover. The p21 activated kinase PAK1 modulates activation of the Raf/MEK/ERK pathway by either directly activating Raf or priming MEK for activation by Raf. Therefore a role for PAK1 in M-CSF-mediated activation of the MEK/ERK pathway controlling osteoclast survival was assessed. Here we show that PAK1 is activated by M-CSF in a Ras-dependent mechanism that promotes osteoclast survival. Surprisingly, PAK1 did not modulate Raf activation or Raf-mediated MEK activation. M-CSF mediated activation of Raf was required for PAK1 activation and osteoclast survival promoted by PAK1. This survival response was MEK-independent as expression of constitutively active MEK did not rescue osteoclasts from apoptosis induced by blocking PAK1 function. Functionally, PAK1 promoted osteoclast survival by modulating expression of the IAP family member Survivin. M-CSF therefore functions to promote PAK1 activation as a novel MEK-independent Raf target to control Survivin-mediated osteoclast survival.     

Large-scale expression, purification, and characterization of an engineered prostacyclin-synthesizing enzyme with therapeutic potential

Recently, we reported that a novel hybrid enzyme (TriCat enzyme), engineered by linking human cyclooxygenase-2 (COX-2) with prostacyclin (PGI₂) synthase (PGIS) together through a transmembrane domain, was able to directly integrate the triple catalytic (TripCat) functions of COX-2 and PGIS and effectively convert arachidonic acid (AA) into the vascular protector, PGI₂ [K.H. Ruan, H. Deng, S.P. So, Biochemistry 45 (2006) 14003-14011]. In order to confirm the important biological activity and evaluate its therapeutic potential, it is critical to characterize the properties of the enzyme using the purified protein. The TriCat enzyme cDNA was subcloned into a baculovirus vector and its protein was expressed in Sf-9 cells in large-scale with a high-yield (∼4% of the total membrane protein), as confirmed by Western blot and protein staining. The Sf-9 cells’ membrane fraction, rich in TriCat enzyme, exhibited strong TriCat functions (K_m = 3 μM and K_cat = 100 molecules/min) for the TriCat enzyme and was 3-folds faster in converting AA to PGI₂ than the combination of the individual COX-2 and PGIS. Another superiority of the TriCat enzyme is its dual effect on platelet aggregation: it completely inhibited platelet aggregation at the low concentration of 2 μg/ml and then displayed the ability to reverse the initially aggregated platelets to their non-aggregated state. Furthermore, multiple substrate-binding sites were confirmed in the single protein by high-resolution NMR spectroscopy, using partially purified TriCat enzyme. These studies have clearly demonstrated that the isolated TriCat enzyme protein functions in the selective biosynthesis of the vascular protector, PGI₂, and revealed its potential for anti-thrombosis therapeutics.     

Molecular characterization of two novel isoforms and a soluble form of mouse CLEC-2

CLEC-2 was first identified by sequence similarity to C-type lectin-like molecules with immune functions. Recently, human CLEC-2 has been reported as a receptor for the platelet-aggregating snake venom toxin rhodocytin and the endogenous sialoglycoprotein podoplanin. It has also been reported to facilitate the capture of HIV-1. However, investigation of mouse CLEC-2 (mCLEC-2) has little progressed after its identification. In this study, we identified two novel splicing variants of mCLEC-2 derived from omission of exon 2 and 2/4, respectively. These two variants had different expression profiles and subcellular localization from full-length mCLEC-2. Moreover, we observed that full-length mCLEC-2 could be cleaved probably by proteases sensitive to aprotinin and PMSF into a soluble form that partially existed as a disulfide-linked homodimer. The results presented here represent a further advancement toward the understanding of mCLEC-2.