Nematicidal efficacy of herbal powders on Meloidogyne incognita (Tylenchida: Meloidogynidae) on potted watermelon

Nine herbal powders were tested against root-knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood (Tylenchida: Meloidogynidae) under greenhouse conditions. The herbal powders were collected from Gezira State, Sudan. Herbal powders were used without extraction to simplify the application by farmers. Most of the herbal powders were effective in controlling M. incognita in the soil compared to the control. Some treatments (e.g., Acacia nilotica (L.), Argemone mexicana L., and Azadirachta indica A. Juss) had statistically lower Root Knot Index (RNI) than the control. The number of juveniles per 100 g soil was lower in soil amended with Dinbera retroflexa (Vahl), Azadirachta indica, Salvadora persica (L.), and Acacia nilotica than in unamended soil. The results of both RNI and number of juveniles were not significantly different from the synthetic nematicide used. Herbal powders from A. indica and Acacia nilotica may be promising in controlling of this pest because they are readily available to farmers in tropical regions.     

Restriction endonuclease mapping of the hepatitis B viral genome isolated from Taiwan

The Eco RI fragment of hepatitis B virus (HBV) DNA isolated from human blood plasma Dane particles were inserted into plasmid pUC8 Eco RI site and transformed into E. coli JM103 host. Two recombinants pTWL1 and pTWL2 were found to carry 3.2 kbp fragment and proved to have HBV genome by Southern hybridization method. The 1.4 kbp Bam HI fragment which carried the hepatitis B viral surface antigen (HBsAg) gene, obtained via Bam HI digestion of Dane particles DNA which was made fully double stranded by endogenous DNA polymerase reaction, was also inserted into plasmid pUC8 Bam HI site. Four recombinant clones, pTWS1, pTWS2, pTWS3, and pTWS4 were found. Only one of the clones pTWS1 carried the HBsAg gene in a correct orientation with respect to the lac promoter sequence. The physical mapping of HBV DNA was performed with several restriction endonucleases. Our results indicated that the HBV DNA insert contains unique XbaI and HpaI cleavage sites and lacks the cleavage sites for the HindIII, SmaI, KpnI, SalI, and SstI endonucleases. The locations of Bam HI, BglII, and HincII endonucleases cleavage sites within the cloned HBV DNA of the pTWL1 plasmid were similar to that HBV DNA of adw and adw2 subtypes.     

Bark morphological and chemical features are differentially correlated with disease resistance and yield in hybrid poplar taxa

In the southeastern United States, the establishment of short-rotation intensively cultured plantations of hybrid poplar has been hindered by its susceptibility to stem cankers. We evaluated the tradeoffs between biomass yield and disease tolerance in hybrid poplar genotypes belonging to P. deltoides × P. maximowiczii (DM), P. deltoides × P. nigra (DN), P. trichocarpa × P. maximowiczii (TM), and P. deltoides × P. deltoides (DD) taxa. We hypothesized that canker resistant genotypes will have thicker bark but bark thickness and biomass yield will be negatively correlated. After two growing seasons, the DD genotypes developed thicker bark compared to the genotypes of other taxa and bark thickness was not correlated with biomass yield in the DD genotypes (R² = 0.002). However, in the TM, DM, and DN genotypes, bark thickness was negatively correlated with biomass yield (R² = 0.33–0.77). Disease incidence studies revealed that the DM genotypes were most susceptible to canker whereas no disease was detected in DD genotypes. Furthermore, bark analysis conducted by Fourier transform infrared spectroscopy coupled with multivariate analysis showed that that DD genotypes to be chemically separate from the three hybrid genotypes and that bark chemistry was correlated with canker disease incidence. Taken together, these results reveal that it is possible to generate hybrid poplar genotypes with thicker bark, disease resistance, and higher biomass yields. This insight should guide further efforts to develop genetically improved hybrid poplar genotypes, both in terms of biomass yield and disease tolerance, for cultivation in the southeastern United States. Hybrid poplar cultivation in southeastern United States is hindered by its susceptibility to stem cankers. We evaluated tradeoffs between yield and canker disease resistance in various hybrid poplar genotypes. After two growing seasons, the DD genotypes showed disease resistance and developed thicker bark that was chemically distinct from the other genotypes. Bark thickness was not correlated with yield in the DD genotypes but was negatively correlated with yield in the other genotypes. These results will guide the development of hybrid poplar genotypes that are both disease resistant and high yielding for cultivation in the southeastern United States.     

PEDAL: a dynamic analysis tool for efficient concurrency bug reproduction in big data environment

Concurrency bugs usually manifest under very rare conditions, and reproducing such bugs can be a challenging task. To reproduce concurrency bugs with a given input, one would have to explore the vast interleaving space, searching for erroneous schedules. The challenges are compounded in a big data environment. This paper explores the topic of concurrency bug reproduction using runtime data. We approach the concurrency testing and bug reproduction problem differently from existing literature, by emphasizing on the preemptable synchronization points. In our approach, a light-weight profiler is implemented to monitor program runs, and collect synchronization points where thread scheduler could intervene and make scheduling decisions. Traces containing important synchronization API calls and shared memory accesses are recorded and analyzed. Based on the preemptable synchronization points, we build a reduced preemption set (RPS) to narrow down the search space for erroneous schedules. We implement an optimized preemption-bounded schedule search algorithm and an RPS directed search algorithm, in order to reproduce concurrency bugs more efficiently. Those schedule exploration algorithms are integrated into our prototype, Profile directed Event driven Dynamic AnaLysis (PEDAL). The runtime data consisting of synchronization points is used as a source of feedback for PEDAL. To demonstrate utility, we evaluate the performance of PEDAL against those of two systematic concurrency testing tools. The findings demonstrate that PEDAL can detect concurrency bugs more quickly with given inputs, and consuming less memory. To prove its scalability in a big data environment, we use PEDAL to analyze several real concurrency bugs in large scale multithread programs, namely: Apache, and MySQL.     

Attraction of Gymnosoma rotundatum (Diptera: Tachinidae) to different amounts of Plautia stali (Hemiptera: Pentatomidae) aggregation pheromone and the effect of different pheromone dispensers

The attractiveness of different amounts of the synthetic aggregation pheromone, methyl (E,E,Z)-2,4,6-decatrienoate, of the brown-winged stink bug, Plautia stali (Hemiptera: Pentatomidae) was tested on its parasitoid, Gymnosoma rotundatum (Diptera: Tachinidae), using different types of dispensers in the field. Both sexes of G. rotundatum were attracted to the aggregation pheromone. Pheromones in rubber septum and poly-tube dispensers attracted significantly more G. rotundatum than those in PE-vial dispensers. There were no differences in the attraction of females or males when using 7 to 60 mg pheromone. However, the trap baited with 50 mg pheromone attracted significantly more G. rotundatum of both sexes than the control trap. Further research is necessary to develop an effective pheromone trap that can attract and kill P. stali and can attract G. rotundatum to increase parasitism of the host stink bugs in the field.     

Glycomodification and characterization of anti-colorectal cancer immunotherapeutic monoclonal antibodies in transgenic tobacco

Anti-colorectal cancer mAb CO17-1A (IgG_2a) recognizes the antigen GA733, which is highly expressed on the surface membrane of human colorectal carcinoma cells. In this study, a transgenic tobacco system for the production of mAb CO17-1A was developed. The mAb construct included a KDEL sequence, an endoplasmic reticulum (ER) retention signal attached to the C-terminus of the heavy chain, to target accumulation of mAb into ER. An immunoblot showed significantly enhanced levels of expression of the plant-derived mAbK (mAb^PK) CO17-1A compared to mAb^P CO17-1A mAb without the KDEL sequence. An ELISA assay using human colorectal carcinoma cells confirmed that expression of mAb^PK was also significantly higher than that of mAb^P. Glycosylation analysis revealed that mAb^P had plant-specific glycans; whereas, mAb^PK primarily had oligomannose glycans. FACS showed that the Fc domains of both mAb^PK and mammalian-derived mAb (mAb^M) had similar binding activity to the FcγRI receptor (CD64). However, the Fc domains of the mAb^P had slightly lower binding activity to the Fc_γRI receptor than both mAb^PK and mAb^M. The antibody-dependent cell cytotoxicity of mAb^PK, against human colorectal cancer cells, was as efficient as mAb^M; whereas mAb^P was very low. These results suggest that KDEL localized and accumulated mAb^P in the ER and eventually enhanced the expression of mAb^P with oligomannose glycan and similar anti-cancer biological activity to the parental mAb^M.     

Kinetic studies of the effect of a 17‐nucleotide difference in the 0.3‐kb region containing the R‐U5‐5′ leader sequence of Friend murine leukemia virus on viral gene expression

In addition to the env gene, a 0.3‐kb fragment containing the R‐U5‐5′ leader sequence is essential for the induction of spongiform neurodegeneration by Friend murine leukemia virus (Fr‐MLV) clone A8 and it also influences expression of the Env protein. Kinetic studies were carried out using two recombinant viruses, R7f, carrying the A8 0.3‐kb fragment, and Rec5, carrying the 0.3‐kb fragment of the non‐neuropathogenic Fr‐MLV clone 57. These analyses suggested that the 0.3‐kb fragment influenced the expression level of the Env protein by regulating the amount of spliced env‐mRNA rather than the amount of total viral mRNA or viral production.