Characterization of a Novel Cr6+ Reducing Pseudomonas sp. with Plant Growth–Promoting Potential

The isolate RNP4 obtained from a long-term tannery waste contaminated soil was characterized and presumptively identified as Pseudomonas sp. The strain RNP4 tolerated concentrations up to 450 mg Cr⁶⁺/L on a Luria-Bartani (LB) agar medium and reduced a substantial amount of Cr⁶⁺ to Cr³⁺ in the LB liquid medium. The ability of performing multifarious activities in tandem suggested the uniqueness of isolate RNP4. The strain produced a substantial amount of indole acetic acid (IAA) in tryptophan-supplemented medium. The strain also exhibited the production of siderophore and solubilization of phosphorus in mineral salt medium and SRS1 medium, respectively. Concurrent production of IAA and siderophore and the solubilization of phosphorus revealed its plant growth promotion potential. Furthermore, the strain was able to promote the growth of black gram, Indian mustard, and pearl millet in the presence of Cr⁶⁺. Thus, the innate capability of this novel isolate for parallel bioremediation and plant growth promotion has significance in the management of environmental and agricultural problems.     

A linkage map of diploid Avena based on RFLP loci and a locus conferring resistance to nine isolates of Puccinia coronata var. ‘avenae’

An F₂ oat population was produced by crossing the diploid (n=7) species Avena strigosa (CI 3815) with A. wiestii (CI 1994), resistant and susceptible, respectively, to 40 isolates of Puccinia coronata, the causal agent of crown rust. Eighty-eight F₂ individuals were used to construct an RFLP linkage map representing the A genome of cultivated hexaploid oat. Two hundred and eight RFLP loci have been placed into 10 linkage groups. This map covers 2416 cM, with an average of 12 cM between RFLP loci. Eighty-eight F₃ lines, derived from F₂ individuals used to construct the map, were screened for resistance to 9 isolates of P. coronata. One locus, Pca, was found to confer a dominant resistance phenotype to isolates 203, 258, 263, 264B, 290, 298, 325A, and 345. Pca also conferred resistance to isolate 276; however, an unlinked second gene may also be involved.Journal Paper No. 15143 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa. Project No. 3134 and 2447     

Can Lactobacillus spp. Be a Factor Reducing the Risk of Miscarriage?

Pregnancy loss is a common obstetric problem. Significant causes of miscarriage include genetic and epigenetic disorders of the embryo, immunological and endocrine factors, uterine malformations, improper embryo selection, and lifestyle. Perhaps a hitherto underappreciated cause of miscarriage may be an abnormal microbiota composition of the female reproductive system. Lactobacillus spp. is the most common bacteria within the reproductive tract. However, the protective role of Lactobacilli in the vagina has been well described in the literature, while it is still unknown what function Lactobacilli may have in the uterus. Moreover, new research shows that Lactobacillus spp. can have a role in miscarriage. However, both molecular and immunological mechanisms of host-Lactobacillus spp. interactions are not fully understood. Understanding these relationships will help address the importance and extent of the protective role of Lactobacillus spp. in miscarriage.     

Time to the MRCA of a sample in a Wright–Fisher model with variable population size

Determining the expected distribution of the time to the most recent common ancestor of a sample of individuals may deliver important information about the genetic markers and evolution of the population. In this paper, we introduce a new recursive algorithm to calculate the distribution of the time to the most recent common ancestor of the sample from a population evolved by any conditional multinomial sampling model. The most important advantage of our method is that it can be applied to a sample of any size drawn from a population regardless of its size growth pattern. We also present a very efficient method to implement and store the genealogy tree of the population evolved by the Galton–Watson process. In the final section we present results applied to a simulated population with a single bottleneck event and to real populations of known size histories.     

Biochemical Studies on “Bakanae” Fungus. Part 58–59. Synthesis of Substances related to Gibberellins

Synthesis of a new lactone of cyclohexane series, 3-methyl-cyclohexane-cis-diol-(2,5) -carboxylic acid lactone, is described. Spectroscopic properties of this and another lactone as well as two related esters are listed.     

Monochoria vaginalis var. angustifolia，a new variety of the Pontederiaceae from Thailand

A new variety of Monochoria C. Presl from Thailand, M. vaginalis （N. L. Burman）Kunth var.angustifolia G. X. Wang, is described. This variety can be distinguished from the typical one, M. vaginalis var. vaginalis, by having mature leaves narrowly lanceolat     

Assigning Brassica microsatellite markers to the nine C-genome chromosomes using Brassica rapa var. trilocularis–B. oleracea var. alboglabra monosomic alien addition lines

Brassica rapa var. trilocularis-B. oleracea var. alboglabra monosomic alien addition lines (MAALs) were used to assign simple sequence repeat (SSR) markers to the nine C-genome chromosomes. A total of 64 SSR markers specific to single C-chromosomes were identified. The number of specific markers for each chromosome varied from two (C3) to ten (C4, C7 and C9), where the designation of the chromosomes was according to Cheng et al. (Genome 38:313-319, 1995). Seventeen additional SSRs, which were duplicated on 2-5 C-chromosomes, were also identified. Using the SSR markers assigned to the previously developed eight MAALs and recently obtained aneuploid plants, a new Brassica rapa-B. oleracea var. alboglabra MAAL carrying the alien chromosome C7 was identified and developed. The application of reported genetically mapped SSR markers on the nine MAALs contributed to the determination of the correspondence between numerical C-genome cytological (Cheng et al. in Genome 38:313-319, 1995) and linkage group designations. This correspondence facilitates the integration of C-genome genetic information that has been generated based on the two designation systems and accordingly increases our knowledge about each chromosome. The present study is a significant contribution to genetic linkage analysis of SSR markers and important agronomic traits in B. oleracea and to the potential use of the MAALs in plant breeding.     

Degradation of the Herbicide Atrazine by the Soil Mycelial Fungus INBI 2-26 (–), a Producer of Cellobiose Dehydrogenase

Nonsporulating mycelial fungi producing cellobiose dehydrogenase (CDH) and isolated from soils of South Vietnam with a high residual content of dioxins are capable of growing on a solid medium in the presence of high atrazine concentrations (to 500 mg/l). At 20 and 50 mg/l atrazine, the area of fungal colonies was 1.5–1.2-fold larger, respectively, than the control colonies of the same age, whereas development of the colonies at 500 mg/l atrazine was delayed by 5 days, compared with controls grown in the absence of atrazine. Surface cultivation of the fungus on a minimal medium with glucose as a sole source of carbon and energy decreased the initial concentration of atrazine (20 mg/l) 50 times in 40 days; in addition, no pronounced sorption of atrazine by mycelium was detected. This was paralleled by an accumulation in the culture medium of extracellular CDH; atrazine increased the synthesis of this enzyme two- to threefold. Accumulation of -glucosidase (a mycelium-associated enzyme) and cellulases preceded the formation of CDH.     

Phylogenetic Relationships of the Genus Paramesotriton （Caudata： Salamandridae） with the Description of a New Species from Qixiling Nature Reserve,Jiangxi, Southeastern China and a Key to the species

The matrilineal genealogy of the genus Paramesotriton is hypothesized based on DNA sequences from mitochondrial NADH subunit two （ND2） and its flanking tRNAs （tRN^Arp and a partial tRNA^Ala）. The genealogy identifies a highly divergent, unnamed lineage from Qixiling Nature Reserve, Jiangxi, China and places it as the sister taxon of P. chinensis. The newly discovered population differs from other congeners by several features of external morphology including having large clusters of dark brown conical warts on the dorsum of the head, lateral surface of the body and dorsolateral ridges. Its intermittent dorsal vertebral ridge is the same color as other parts of the dorsum and tail narrows gradually from the base to the tip. Further, the new population differs from all congeners by an uncorrected P-distance of more than 9.38% in ND2. Consequently, we describe the new species of Asian warty newt （Salamandridae） as Paramesotriton qixilingensis sp. nov.     

Description of the type-series of Palaeocryptonyx donnezani Depéret, 1892 (Aves: Phasianidae) with the selection of a lectotype

We have re-examined the original type-series of Palaeocryptonyx donnezani Depéret, 1892 housed in the Laboratoire de Géologie de Lyon, Université Claude-Bernard Lyon 1 (France), and have selected a lectotype and paralectotypes. P. donnezani is the type species of the extinct genus Palaeocryptonyx, known from six species from different European Neogene and Pleistocene fossil localities. The species have been compared with different medium-sized Phasianidae species on the basis of our own study and data from the literature. The systematic position of P. donnezani has been questioned, because it has been misplaced in the extant genera Alectoris and Coturnix, but our analysis confirms its validity and its attribution to a separate genus; hence we also confirm the validity of the genus Palaeocryptonyx.     

Neuromuscular control of the point to point and oscillatory movements of a sagittal arm with the actor–critic reinforcement learning method

In this study, we have used a single link system with a pair of muscles that are excited with alpha and gamma signals to achieve both point to point and oscillatory movements with variable amplitude and frequency.

The system is highly nonlinear in all its physical and physiological attributes. The major physiological characteristics of this system are simultaneous activation of a pair of nonlinear muscle-like-actuators for control purposes, existence of nonlinear spindle-like sensors and Golgi tendon organ-like sensor, actions of gravity and external loading. Transmission delays are included in the afferent and efferent neural paths to account for a more accurate representation of the reflex loops.

A reinforcement learning method with an actor–critic (AC) architecture instead of middle and low level of central nervous system (CNS), is used to track a desired trajectory. The actor in this structure is a two layer feedforward neural network and the critic is a model of the cerebellum. The critic is trained by state-action-reward-state-action (SARSA) method. The critic will train the actor by supervisory learning based on the prior experiences. Simulation studies of oscillatory movements based on the proposed algorithm demonstrate excellent tracking capability and after 280 epochs the RMS error for position and velocity profiles were 0.02, 0.04?rad and rad/s, respectively.     

On the accuracy of a diffusion approximation to a discrete state–space Markovian model of a population

The traditional Kolmogorov equations treat the size of a population as a discrete random variable. A model is introduced that extends these equations to incorporate environmental variability. Difficulties with this discrete model motivate approximating the population size as a continuous random variable through the use of diffusion processes. The set of cumulants for both the population size and the environmental factors affecting the population size characterize the population–environmental system. The evolution of this set, as predicted by the diffusion approximation, closely matches the corresponding predictions for the discrete model. It is also noted that the simulation estimates of the cumulants against which the predictions of the diffusion model are checked can vary considerably between simulations — despite averaging over a large number of simulation runs. The precision of the simulation estimates–both over time and with differing cumulant order–is discussed.     

Description of Pyramimonas diskoicola sp. nov. and the importance of the flagellate Pyramimonas (Prasinophyceae) in Greenland sea ice during the winter–spring transition

Pyramimonas Schmarda is a genus of unicellular green flagellates, recorded in marine water and sea ice samples. Pyramimonas is within the prey size range of the most important protozoan grazers in Disko Bay, West Greenland, where this study took place. Despite the potential ecological importance, little is known about the occurrence of the genus. The aim of this study was to explore the biomass of Pyramimonas in developing stages of sea ice and in the water column. Pyramimonas colonized the early stages of sea ice, and the highest percent of Pyramimonas biomass was found in grease ice. The biomass of Pyramimonas was more than a magnitude higher within sea ice compared to the surface water. The results illustrate that Pyramimonas from the ice is an important contributor to the plankton community prior to the spring bloom. An undescribed species, Pyramimonas diskoicola sp. nov., was found. Based on morphology and ultrastructure, combined with molecular phylogeny inferred from the small-subunit SSU rDNA and the large-subunit chloroplast-encoded rbcL, the species was placed in subgenus Vestigifera. The cells possessed four flagella, measured 8.3 ± 2.6 μm in length and 5.1 ± 0.8 μm in width, and were characterized by an uplifted quadrant in the center of the box scales, not seen at any other Pyramimonas species. The phylogenetic analyses indicated P. diskoicola to be closely related to other polar sea ice species of Pyramimonas.