Morphological,biochemical, and molecular characterization of Oscillatoria kawamurae (Oscillatoriales,Cyanobacteria) isolated from different geographical regions

Oscillatoria kawamurae is an unusual freshwater cyanobacterium because of its large trichome and ambiguous gas vacuole. Because little is known about its phenotypic or genotypic characteristics, this study conducted morphological, biochemical, and genetic characterization of O. kawamurae strains isolated from Japan, Laos, and Myanmar. All strains displayed similar morphological characteristics; however some differences were observed in vegetative cell widths, trichome colors, and the distribution patterns of their gas vacuole‐like structures. The in vivo and phycobiliprotein absorption spectra revealed the two different trichome colors found in the four representative strains of O. kawamurae (Inle1, Lao7, Biwa6, and Inba3). These different trichome colors corresponded to the different ratios of phycoerythrin and phycocyanin, the two types of phycobilin pigments: 0.25 for olive‐green strain (Inle1) and 0.65–0.73 for brown‐green strains (Biwa6, Inba3, and Lao7). Cellular fatty acid compositions of the four strains were C14:0, C15:0, C16:0, C16:1c, C17:0, C18:0, C18:1c, C18:3α and C18:4, whereas two strains (Biwa6 and Inba3) lacked C17:0. Of the fatty acids, palmitic acid (C16:0) was predominant. PCR experiments using primers targeting a gas vesicle gene (gvpA) recovered gvpA fragments from all O. kawamurae strains, suggesting that this species has true gas vacuoles. The 16S rDNA sequences of all of the strains were identical regardless of their different trichome colors and/or geographic origins. Phylogenetic analyses based on the 16S rDNA sequences indicated that O. kawamurae forms a monophyletic clade with O. princeps CCALA 1115 clB1 and O. duplisecta ETS‐06. We discuss the taxonomy of O. kawamurae based on the data obtained in this study.     

Temperature and heat production patterns inside organism clusters

Clustering of organisms under cold air temperature conditions is modelled with a finite-difference method. Metabolic functions of temperature are used to simulate completely ectothermic, completely endothermic, and other organisms. To adequately match real conditions, the core temperature is kept constant at a high level, while the periphery of the organism cluster is assigned a lower temperature representing the cold conditions under which clustering is observed for organisms. The numerical model reasonably predicts the observed temperature distribution in honeybee clusters. The results do not support suggestions that organisms could overheat in the core of a cluster if they do not use thermoregulatory mechanisms to cool down. Endothermic organisms are not as efficient as ectothermic ones in heating a cluster core temperature to a given level. The general ectothermic metabolic rate function exhibited one of the highest efficiencies for heating the cluster.     

Genotypic analysis of Mycobacterium leprae isolates from Japan and other Asian countries reveals a global transmission pattern of leprosy

The genotype of single-nucleotide polymorphism type 3, CTC, at positions 14676, 164275, and 2935685, along with four copies of 6 bp repeats in the rpoT gene, was predominant for isolates originating in the Japanese mainland. Type 1, CGA, type 2, CTA, and type 3 were detected from Korea, Indonesia, and Myanmar. No isolates with four copies of 6 bp were detected from Myanmar, Okinawa, and Japanese Brazilian patients. Type 4, TTC, with three copies of 6 bp, was detected only from Japanese Brazilians. The results indicate that infection occurred in Brazil and the disease developed later in Japan.     

A new primate from the Eocene Pondaung Formation of Myanmar and the monophyly of Burmese amphipithecids

The family Amphipithecidae is one of the two fossil primate taxa from Asia that appear to be early members of the anthropoid clade. Ganlea megacanina, gen. et sp. nov., is a new amphipithecid from the late middle Eocene Pondaung Formation of central Myanmar. The holotype of Ganlea is distinctive in having a relatively enormous lower canine showing heavy apical wear, indicating an important functional role of the lower canine in food preparation and ingestion. A phylogenetic analysis of amphipithecid relationships suggests that Ganlea is the sister taxon of Myanmarpithecus, a relatively small-bodied taxon that has often, but not always, been included in Amphipithecidae. Pondaungia is the sister taxon of the Ganlea + Myanmarpithecus clade. All three Pondaung amphipithecid genera are monophyletic with respect to Siamopithecus, which is the most basal amphipithecid currently known. The inclusion of Myanmarpithecus in Amphipithecidae diminishes the likelihood that amphipithecids are specially related to adapiform primates. Extremely heavy apical wear has been documented on the lower canines of all three genera of Burmese amphipithecids. This distinctive wear pattern suggests that Burmese amphipithecids were an endemic radiation of hard object feeders that may have been ecological analogues of living New World pitheciin monkeys.     

Estimating abundance with sparse data: tigers in northern Myanmar

As part of a national strategy for recovering tiger populations, the Myanmar Government recently proposed its first and the world’s largest tiger reserve in the Hukaung Valley, Kachin State. During November 2002–June 2004, camera-traps were used to record tigers, identify individuals, and, using capture–recapture approaches, estimate density in the reserve. Despite extensive (203 trap locations, 275–558 km² sample plots) and intensive (>4,500 trap nights, 9 months of sampling) survey efforts, only 12 independent detections of six individual tigers were made across three study sites. Due to the sparse data, estimates of tiger abundance generated by Program CAPTURE could not be made for all survey sites. Other approaches to estimating density, based on numbers of tigers caught, or derived from borrowed estimates of detection probability, offer an alternative to capture–recapture analysis. Tiger densities fall in the range of 0.2–2.2 tigers/100 km², with 7–71 tigers inside a 3,250 km² area of prime tiger habitat, where efforts to protect tigers are currently focused. Tiger numbers might be stabilized if strict measures are taken to protect tigers and their prey from seasonal hunting and to suppress illegal trade in wildlife. Efforts to monitor abundance trends in the tiger population will be expensive given the difficulty with which tiger data can be obtained and the lack of available surrogate indices of tiger density. Monitoring occupancy patterns, the subject of a separate ongoing study, may be more efficient.     

Metabolic pathways variability and sequence/networks comparisons

Background  

In this work a simple method for the computation of relative similarities between homologous metabolic network modules is presented. The method is similar to classical sequence alignment and allows for the generation of phenotypic trees amenable to be compared with correspondent sequence based trees. The procedure can be applied to both single metabolic modules and whole metabolic network data without the need of any specific assumption.     

OPTIMUM POLLEN AND FEMALE RECEPTOR SIZE FOR ANEMOPHILY

A set of mathematical models is developed to describe the relationship between the sizes of pollen grains and female receptors which result in maximum anemophilous pollen transfer. The models predict anemophilous plants should have Stokes numbers in the range of 1.0 to 2.72. The Stokes number is a function of both pollen size and effective receptive surface size. The models were tested with data gathered for 28 assumed anemophilous species and 20 known zoophilous species. The models identify anemophily with an accuracy of approximately 75%. If pollen size alone is used to determine anemophily, then accuracy drops to only 50%. The Stokes number criterion reported here could help in the determination of anemophily of extant and fossil plant taxa.