Establishment of the biological control agent Hypocosmia pyrochroma for Dolichandra unguis-cati (Bignoniaceae) is limited by microclimate

Cat's claw creeper, Dolichandra unguis-cati (Bignoniaceae), a perennial woody vine native to tropical America, is a target for biological control in Australia and South Africa. The cat's claw creeper leaf-tying moth Hypocosmia pyrochroma (Lepidoptera: Pyralidae) from tropical South America was released as a biological control agent for cat's claw creeper in Australia from 2007 to 2010. A total of 2,277 adults, 837 pupae and 77,250 larvae were released at 40 sites in Queensland and New South Wales. Releases were made mostly in open fields (85%), and at limited sites (15%) in insect-proof cages erected over naturally occurring cat's claw creeper infestations in the field. Sampling was conducted annually in spring and autumn to monitor the establishment and dispersal of H. pyrochroma. Establishment of H. pyrochroma was first noticed in 2012 at three release sites and since then the number of established sites has increased to 80 in 2020. Establishment was evident on both ‘short-pod’ and ‘long-pod’ forms of cat's claw creeper and was more widespread in sites where releases were made within insect-proof field cages (50%) than in sites with open field releases (9%). The moth was active from late spring to late autumn with peak larval activity in late summer. To date, all field establishments have been in areas predicted by a CLIMEX model as climatically suitable but restricted mostly to riparian environment (93% of establishment), where the moth has continued to spread from 1.5 to 23 km from release sites. In contrast, there is the only limited establishment and spread in non-riparian corridors, highlighting the role of microclimate (riparian) as a limiting factor for establishment and spread. Future efforts will focus on redistribution of the agent to river/creek systems where the moth is currently not present.     

Comprehensive Analysis of Synonymous Codon Usage Bias for Complete Genomes and E2 Gene of Atypical Porcine Pestivirus

Atypical porcine pestivirus (APPV) is an emerging novel pestivirus causing the congenital tremor (CT) in piglets. The worldwide distribution characteristic of APPV make it a threat to global swine health. E2 is the major envelope glycoprotein of APPV and the crucial target for vaccine development. Considering the genetic variability of APPV complete genomes and its E2 gene as well as gaps for codon analysis, a comprehensive analysis of codon usage patterns was performed. Relative synonymous codon usage (RSCU) and effective number of codon (ENC) analyses showed that a relatively instable change existed and a slight low codon usage bias (CUB) were displayed in APPV genomes. ENC-plot analysis and correlation analyses of nucleotide compositions and ENC showed that mutation pressure and natural selection both affected the codon usage bias of the APPV and natural selection had a more obvious influence for E2 gene compared with complete genomes. Principal component analysis (PCA) and correlation analyses confirmed the above results. Correlation analyses between Gravy and Aromaticity values and the codon bias showed that natural selection played an important role in shaping the synonymous codon bias. Furthermore, neutrality plot analysis showed that natural selection was the main force while mutation pressure was a minor force influencing the codon usage pattern of the APPV E2 gene and complete genomes. The results could illustrate the codon usage patterns of APPV genomes and provided valuable basic data for further fundamental research of evolution of APPV.

     

Comparison of hinge microflow fields of bileaflet mechanical heart valves implanted in different sinus shape and downstream geometry

The characterization of the bileaflet mechanical heart valves (BMHVs) hinge microflow fields is a crucial step in heart valve engineering. Earlier in vitro studies of BMHV hinge flow at the aorta position in idealized straight pipes have shown that the aortic sinus shapes and sizes may have a direct impact on hinge microflow fields. In this paper, we used a numerical study to look at how different aortic sinus shapes, the downstream aortic arch geometry, and the location of the hinge recess can influence the flow fields in the hinge regions. Two geometric models for sinus were investigated: a simplified axisymmetric sinus and an idealized three-sinus aortic root model, with two different downstream geometries: a straight pipe and a simplified curved aortic arch. The flow fields of a 29-mm St Jude Medical BMHV with its four hinges were investigated. The simulations were performed throughout the entire cardiac cycle. At peak systole, recirculating flows were observed in curved downsteam aortic arch unlike in straight downstream pipe. Highly complex three-dimensional leakage flow through the hinge gap was observed in the simulation results during early diastole with the highest velocity at 4.7 m/s, whose intensity decreased toward late diastole. Also, elevated wall shear stresses were observed in the ventricular regions of the hinge recess with the highest recorded at 1.65 kPa. Different flow patterns were observed between the hinge regions in straight pipe and curved aortic arch models. We compared the four hinge regions at peak systole in an aortic arch downstream model and found that each individual hinge did not vary much in terms of the leakage flow rate through the valves.     

Development of a DNA Microarray Method for Detection and Identification of All 15 Distinct O-Antigen Forms of Legionella pneumophila

Legionella is ubiquitous in many environments. At least 50 species and 70 serogroups of the Gram-negative bacterium have been identified. Of the 50 species, 20 are pathogenic, and Legionella pneumophila is responsible for the great majority (approximately 90%) of the Legionnaires'' disease cases that occur. Furthermore, of the 15 L. pneumophila serogroups identified, O1 alone causes more than 84% of the Legionnaires'' disease cases that occur worldwide. Rapid and reliable assays for the detection and identification of L. pneumophila in water, environmental, and clinical samples are in great demand. L. pneumophila bacteria are traditionally identified by their O antigens by immunological methods. We have recently developed an O serogroup-specific DNA microarray for the detection of all 15 distinct O-antigen forms of L. pneumophila, including serogroups O1 to O15. A total of 35 strains were used to verify the specificity of the microarray, including 15 L. pneumophila O-antigen standard reference strains and seven L. pneumophila clinical isolates as target strains, seven reference strains of other non-pneumophila Legionella species as closely related strains, and six non-Legionella bacterial species as nonrelated strains. The detection sensitivity was 1 ng of genomic DNA or 0.4 CFU/ml in water samples with filter enrichment and plate culturing. This study demonstrated that the microarray allows specific, sensitive, and reproducible detection of L. pneumophila serogroups. To the best of our knowledge, this is the first report of a microarray serotyping method for all 15 distinct O-antigen forms of L. pneumophila.     

Early Pleistocene Equus (Equidae,Perissodactyla) from Andersson Loc. 32 in Qixian,Shanxi, China

The Equus specimens of Andersson Loc. 32 in Qixian, Shanxi previously identified as Equus cf. sanmeniensis are rediscovered in this research. The skull has moderate size, deep nasal notch, clear preorbital fossa, undulated lateral outline, upper cheek tooth with simple fossette and incisor with incomplete cup, should be identified as Equus teilhardi. The mandible has cheek tooth with V-shaped linguaflexid, incisor with incomplete cup, moderate size, strong pli caballinid and deep ectoflexid on molar, should be identified as Equus qingyangensis. This skull is first record of a complete cranial material of E. teilhardi, reveals many important cranial features of E. teilhardi, supports anatomical comparison and phylogenetic discussion with other stenonid horses. The morphological differences between E. teilhardi and E. qingyangensis show their different niches, further explain the reason of their coexistence. Incomplete cup on incisor is an unstable feature. It has been found in several species of stenonid horses, likely a remaining feature derived from the most primitive Equus, Equus simplicidens. The small-sized stenonid horses with short limbs and incisors with incomplete cups likely have relation with E. teilhardi, such as Equus yunnanensis and Equus stehlini. E. qingyangensis has most primitive features in Eurasian stenonid horses.     

Development of a DNA microarray to identify the Streptococcus pneumoniae serotypes contained in the 23-valent pneumococcal polysaccharide vaccine and closely related serotypes

Streptococcus pneumoniae is a major worldwide human pathogen. This investigation has developed a reliable and accurate DNA microarray method for inter-species differentiation of S. pneumoniae and intra-species differentiation of the 23 groups of S. pneumoniae including serotypes represented in the 23-valent pneumococcal vaccine and the other 20 closely related serotypes. In addition to 16S rDNA probes, serotype- or serogroup-specific probes targeting the capsular polysaccharide synthesis (cps) genes, wzy or capA were generated. We adopted a two-step multiplex PCR to improve the sensitivity of detection to a level of 10(5) cfu/ml in pure culture or 50 ng DNA. A total of 169 isolates (from China, Australia, Canada and New Zealand) including 147 belonging to 23-valent vaccine and closely related serotypes of S. pneumoniae, 11 belonging to other serotypes and 11 of different species commonly isolated from respiratory tract were tested to verify the method. The DNA microarray method developed provides a sensitive means to rapidly identify the members of the most common S. pneumoniae serotypes in patients and to monitor their distribution in different patient groups and geographic locations. Such information is needed for disease surveillance and to monitor vaccine efficacy.