Diversity analysis of Rhacophorus margaritifer (Schlegel, 1837) in Baturraden based on RAPD markers

Rhacophorus margaritifer is an endemic species of arboreal frog in Java. Previous studies found this frog in several locations of Baturraden, namely in primary forest of Ketenger area, along Pancuran Pitu tourism track, and Baturraden Botanical Garden. There were still limited studies of molecular diversity of R. margaritifer and no prior data from population in the southern slope of Mount Slamet. This study aimed to look at the genetic polymorphism and determine the locus diversity of R.margaritifer population in Baturraden by using the PCR-RAPD technique. Frog tissue samples were taken from three populations in Kalipagu hiking trail (HPK 01), Baturraden hiking trail (HPK 02), and Baturraden Botanical Garden (KRB). DNA was extracted using the Chelex method. Molecular characterization was performed based on RAPD markers. The RAPD marker band pattern was changed to binary data 0-1 and analysed using Arlequin software ver.3.5. A total of 19 frog individuals were obtained during sampling at three locations. High genetic diversity had been observed in all populations with gene diversity range from 0.9643 in HPK 01 population to 1.0000 in both KRB and HPK 02 populations. A high locus variation was also observed for all populations with values of 0.159524 in KRB; 0.165816 in HPK 01; 0.192857 in HPK 02, respectively. AMOVA indicated no genetic difference among populations of R. margaritifer (p=0.50244).

Validation of Hot Corrosion and Fatigue Models in HOTPITS

HOTPITS is a set of physics-based modeling tools for treating Type II hot corrosion in Ni-based superalloys. The methodology includes modeling the nucleation, growth, and coalescence of pits and microcracks as a random process, as well as the transition of pits to micrcracks and the propagation of the resulting large crack to failure. In this investigation, critical experiments were performed on coupon and low-cycle fatigue (LCF) specimens in order to validate the hot corrosion and the fatigue models in HOTPITS. The pit nucleation, growth, and coalescence models in HOTPITS including the assumption of a random process are validated by the hot corrosion critical experiments performed at two salt contents. The LCF critical experiments, performed using a marker band protocol, validated the stress concentration factor-based models used to predict the pit-to-crack transition in the HOTPITS tool.

Development and Validation of a Gene-Targeted dCAPS Marker for Marker-Assisted Selection of Low-Alkaloid Content in Seeds of Narrow-Leafed Lupin (Lupinus angustifolius L.)

Low-alkaloid content is an important breeding target to improve the quality of lupin seeds. An APETALA2/ethylene response transcription factor, RAP2-7, is likely a candidate gene for the major alkaloid locus iucundus, and plays a crucial role in regulation of seed alkaloid content in narrow-leafed lupin (NLL; Lupinus angustifolius L.). Here, we exploited a single-nucleotide polymorphism within RAP2-7 credibly associated with seed alkaloid content, to develop the co-dominant derived cleaved amplified polymorphic sequence (dCAPS) marker iuc_RAP2-7. Marker validation in 202 NLL accessions demonstrated that seed alkaloid content ≥0.9% of the seed dry weight was associated with the high-alkaloid marker band (Iucundus genotypes), whereas alkaloid content up to 0.5% of the seed dry weight was associated with the low-alkaloid marker band (iucundus genotypes). Within a given detection limit, iuc_RAP2-7 unambiguously identified all but three low-alkaloid accessions. The latter accessions apparently have a different regulatory mechanism for seed alkaloid content because the RAP2-7 gene/putative promoter sequence and expression of alkaloid-associated genes in the leaves of the three ambiguous accessions were similar to those of bitter Iucundus lines. We consider the iuc_RAP2-7 marker is a powerful tool that will facilitate NLL marker-assisted selection by rapid rejection of bitter Iucundus genotypes and thus accelerate development of new low-alkaloid cultivars.

Republished: Delayed ischemic stroke due to stent marker band occlusion after stent-assisted coiling

A middle-aged patient with an internal carotid-posterior communicating artery aneurysm and basilar artery tip aneurysm was treated by stent-assisted coiling. One ischemic infarction and two transient ischemic attacks occurred with the same symptoms (inability to walk unassisted and tendency to fall to the left) during the first 2 years post-treatment. The ischemic infarction was found in the right side of the pons, consistent with the vascular territory of the stent-containing vessel. The cause of the delayed ischemic stroke was investigated on DSA and cone beam CT, which revealed that the proximal end of the stent, one marker band, was just covering a small perforating artery of the basilar artery trunk. The present case suggests that marker band occlusion can induce delayed ischemic stroke. To prevent this complication, it is important to evaluate the perforating vessels preoperatively and carefully deploy a stent for the marker band to avoid occlusion of large perforating vessels. Post-treatment evaluation is also important because dual antiplatelet therapy will be required for a longer period if an artery is occluded by a marker band.

A Modified Compliance Method for Automatically Measuring Fatigue Crack Growth In Situ during Spectrum Fatigue Testing

The fatigue critical structures of military aircraft are generally subjected to variable amplitude flight spectrum loading. Maintaining aircraft structural integrity to ensure safe operation of the fleet is critically dependent on accurate analysis and reliable prediction of fatigue crack growth in those structures under service operating conditions. To achieve this goal, laboratory experimental methods that can accurately measure and monitor fatigue crack growth under variable amplitude loading are required. This can be challenging as no test standard exists to guide the process of fatigue crack growth measurement under variable amplitude loading conditions to ensure the accuracy of the test results. This challenge was addressed by developing a modified compliance method as described in this paper. The results presented employed a modified compliance method complemented with a travelling microscope technique and marker band loads. The modified compliance method developed is able to measure in-situ, fatigue crack growth of standard compact-tension specimens under a fighter flight spectrum loading. The marker band loads and microscope readings were used to assist the post-test validation using quantitative fractography. The results from this study have demonstrated that the modified compliance method can produce consistent and accurate fatigue crack growth data under variable amplitude loading conditions.

Genetic purity testing of pumpkin hybrid seed by ultrathin-layer isoelectric focusing

Ultrathin-layer isoelectric focusing of seed proteins was used to test the genetic purity of pumpkin hybrid seeds. In the pH range of 5-8, one male marker band and two female marker bands were found in the male and female parental line, respectively. Based on the male marker band and female marker bands, the genetic purity of F1 seeds can easily be determined in the laboratory.