Evolution and ecology of the Ceanothus-Frankia symbiosis

The evolutionary relationship between Frankia and actinorhizal plants was evaluated by reconstructing molecular phylogenetic trees from nifH, 16S rDNA, and rbcL nucleotide sequences. Subgroupings in Frankia phylogenetic trees reconstructed from nifH and from 16S rDNA sequences were consistent in terms of plant origins of Frankia strains. Although the branching order of Frankia 16S rDNA and plant rbcL trees were different, subgroupings of Frankia and of plants correlated well in terms of symbiotic partnership. Tree matching, estimated divergence times, and molecular clock hypothesis tests indicated that Frankia clades diverged more recently than plant clades and that actinorhizal symbioses originated more than three times after the plant clades diverged. A phylogenetic tree of Ceanothus species, which are symbiotic partners of Frankia, was reconstructed using ndhF gene sequences. The analysis identified two main clades corresponding to two subgenera: Ceanothus and Cerastes. The analysis also suggested that three monophyletic clades within the subgenus ceanothus can be delimited on the basis of vegetative characters. Based on rbcL sequences, the two subgenera diverged 18-39 million years ago whereas species within each subgenus diverged more recently. These results support the current division of Ceanothus into two monophyletic subgenera and agree with the postulated recent divergence of many species within each subgenus. Specificity between Ceanothus species and their Frankia microsymbionts was evaluated by analysis of DNA in nodules collected from three copopulations of Ceanothus species. Sequencing of the intergenic spacer region between 16S and 23S rRNA genes suggested that Ceanothus-microsymbiont Frankia are closely related. Nodules were further analyzed by genomic fingerprinting using repetitive sequences and PCR (rep-PCR). A newly designed, direct repeat sequence and a BOX sequence showed that Ceanothus-microsymbiont Frankia exhibited less diversity within each copopulation than among copopulations. Furthermore, geographic separation was a more important factor for divergence of Ceanothus-microsymbiont Frankia than host plant. The population of Ceanothus-infective Frankia in soils under stands of Ceanothus velutinus and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), a non-host plant, were compared. The population sizes were measured using plant bioassay methods with C. velutinus, C. sanguineus, and C. integerrimus as trap plants. Population size in soil under C. velutinus was about 10 times higher than that under the Douglas-fir. Nodulation capacities of the three trap plants were not significantly different. The diversity of Frankia nodulating trap plants was examined using rep-PCR. Results suggested that infective Frankia is not species-specific with regard to the three Ceanothus species used as trap plants and that although the degree of diversity was similar in both soils, the two populations consisted of different Frankia

Force-sensitive resistors to measure the distribution of weight in the pads of sound dogs in static standing position

The purpose of this study was to measure how weight is distributed in the pads of each of the 4 limbs of dogs and evaluate the intra-investigator reproducibility and inter-investigator reliability of the measurement method. Eight dogs were examined 3 times a day by 3 investigators at 1 week intervals for 3 weeks to determine the weight distribution to each of the pads. The force-sensitive resistor was used for measurement and specific software (PetLAB2) was used to calculate the weight applied to each pad. The intra-investigator reproducibility showed moderate to good reliability (ICC range, 0.575-0.873) and the inter-investigator reliability was moderate (ICC range, 0.525-0.746). Based on this study, it can be observed whether the weight distributed to each pad approaches the normal value after treatment in patients with orthopaedic and neurologic diseases. It is expected that this experimental method will be one of the objective indicators to evaluate the degree of recovery in patients with orthopaedic and neurologic diseases

Synthesis of micro-assembled Si/titanium silicide nanotube anodes for high-performance lithium-ion batteries

Chemical reduction of micro-assembled CNT@TiO2@SiO2 leads to the formation of titanium silicide-containing Si nanotubular structures. The Si-based nanotube anodes exhibit a high capacity (>1850 mA h g-1) and an excellent cycling performance (capacity retention of >99% after 80 cycles).close5

Steatocystoma Multiplex Confined to the Scalp with Concurrent Alopecia

Steatocystoma multiplex (SM) is an uncommon disorder of the pilosebaceous unit characterized by the development of numerous sebum-containing dermal cysts which rarely involves the scalp. Here, we report a case of a 50-year-old man with multiple cystic nodules and alopecic patches on his scalp. On histopathological examination, the folded cyst was found to be lined by stratified squamous epithelium, while flattened sebaceous gland cells were identified in the cystic wall. Pigment casts were present in the hair papillae and perifollicular regions, suggesting trichotillomania as a possible cause of the observed alopecia. This case appears to represent an unusual clinical manifestation of SM

Log-transformed plasma level of brain natriuretic peptide during the acute phase of Kawasaki disease is quantitatively associated with myocardial dysfunction

PurposeBrain natriuretic peptide (BNP) has been considered a biochemical marker for myocarditis in Kawasaki disease. We performed this study to determine its quantitative significance.MethodsWe attempted to correlate log-transformed BNP concentrations (log-BNP) and clinical, laboratory, and echocardiographic variables in 81 children with Kawasaki disease. Stepwise multiple linear regression analysis was used to determine the variables independently associated with log-BNP concentration.ResultsSerum C-reactive protein level (P<0.0001), serum alanine aminotransferase concentration (P=0.0032), white blood cell count (P=0.0030), and left ventricular mass index (P=0.0024) were positively related with log-BNP, and hemoglobin level (P<0.0001), serum albumin level (P<0.0001), Na+ concentrations (P<0.0001), left ventricular fractional shortening (P=0.0080), and peak early diastolic tissue velocity of the left ventricular basal lateral segment (P=0.0045) were negatively related to the log-BNP concentration. Multiple regression analysis showed that serum albumin concentration (R2=0.31, P=0.0098) and left ventricular mass index (R2=0.09, P=0.0004) were significantly associated with the log-BNP concentration.ConclusionElevated BNP levels during the acute phase of Kawasaki disease may be attributable to cardiac dysfunction associated with the increase in left ventricular mass, and log-BNP concentration may be a quantitative biochemical marker of myocarditis in Kawasaki disease

Complete genome sequence of Middle East respiratory syndrome coronavirus KOR/KNIH/002_05_2015, isolated in South Korea

The full genome sequence of a Middle East respiratory syndrome coronavirus (MERS-CoV) was identified from cultured and isolated in Vero cells. The viral genome sequence has high similarity to 53 human MERS-CoVs, ranging from 99.5% to 99.8% at the nucleotide level. © 2015 Kim et al.

Intra-host competition and interactions between Soybean mosaic virus (SMV) strains in mixed-infected soybean

Abstract Over the past two decades, the dominant Soybean mosaic virus (SMV) strain in South Korea has changed from G5 to G7H. To examine the dominance of G7H, intra-host competition between G7H and G5 was evaluated in soybean plants infected with a mixture of SMV strains. The distribution patterns of the two SMV strains in soybean plants inoculated with G7H, G5 and G7H/G5 were investigated at designated time points by RT-PCR/RFLP analysis, which enables the specific differentiation of low concentrations of SMV strains and the detection of mixed infection at any given time. When leaves of &apos;Kwangankong&apos; and &apos;Tawonkong&apos; were infected with both strains, the upper leaves had only the G7H strain in simultaneous infections. In sequential inoculations, the leaves exhibited mosaic symptoms caused by G7H, and the G5 strain was not detected in plants pre-inoculated with the G7H strain before inoculation with the G5 strain. In the reverse treatment, both G5 and G7H were present at every vegetative stage. In addition, interactions between the virulence and dominance of G7H, G5, and G1, a less virulent strain, were investigated. Three landrace soybeans were co-inoculated with G7H/G5, G7H/G1, G5/G1, and G7H/G5/G1 sets. There was no significant difference between virulence and dominance. These results demonstrate the dominance of G7H in mixed infections and could explain the prevalence of G7H in South Korea