Mitochondrial DNA supports the identification of two endangered river sharks (Glyphis glyphis and Glyphis garricki) across northern Australia

The river sharks (genus Glyphis) are a small group of poorly known sharks occurring in tropical rivers and estuarine waters across northern Australia, south-east Asia and the subcontinent. The taxonomy of the genus has long been unclear due to very few individuals having been caught and examined, resulting in a paucity of data regarding their distribution, biology and ecology. Only recently has attention focussed on the two Australian species, G. glyphis and G. garricki. This study is a result of a rare opportunity to collate the few samples that have been collected from these species and the bull shark Carcharhinus leucas, which shares an overlapping range. These samples were analysed using the DNA barcoding approach (cox1 mitochondrial gene), compared with six other species of carcharhinids and evaluated in light of the current taxonomic classification. Nine species-specific nucleotide differences were found between G. glyphis and G. garricki and no intra-specific variation provides strong support for the separation into distinct species. Significant differences were also observed at the inter-generic level, with Glyphis forming a distinct clade from Carcharhinus. This study provides the basis for future molecular studies required to better address conservation issues confronting G. glyphis and G. garricki in Australia.

Responses of two species of mesquite to initial and follow-up applications of selected herbicides in a potted trial

Quilpie mesquite (Prosopis velutina) is an invasive woody weed that is believed to have been introduced into south-west Queensland in the 1930s. Following the withdrawal of 2,4,5-T, research on P. pallida resulted in revised recommendations for control of all Prosopis spp. in Queensland. Adoption of many of these recommendations for Quilpie mesquite control produced substandard results. Following a pilot trial, a shade-house experiment was conducted to determine the differences in susceptibility of two species of mesquite, P. velutina and P. pallida, to commonly available herbicides. It was hypothesized that P. velutina was less susceptible than P. pallida, based upon claims that the registered chemical recommendations for Prosopis spp. were not sufficiently effective on P. velutina. Nine foliar herbicide treatments were applied to potted shade-house plants. Treatment effects indicated differing susceptibility between the two species. P. velutina consistently showed less response to metsulfuron, fluroxypyr, 2,4-D/picloram and triclopyr/picloram, compared to the glyphosate formulations, where negligible differences occurred between the two species. The response to glyphosate was poor at all rates in this experiment. Re-application of herbicides to surviving plants indicated that susceptibility can decrease when follow-up application is in autumn and the time since initial application is short. The relationship between leaf structure and the volume of spray adhering to a plant was assessed across species. The herbicide captured by similar-sized plants of each species differed, with P. pallida retaining a greater volume of herbicide.

One device, two doses

Ms Breathless is a 59-year-old lady living with chronic obstructive pulmonary disease (COPD) for several years now, and quit smoking over 20 years ago. She sometimes experiences symptoms of breathlessness, and an unrelenting productive cough, particularly when she comes in contact with dusty places, second-hand smoke, or when her allergies and hay fever play up. Apart from these triggers, her symptoms are well maintained with her inhalers glycopyrronium bromide (Seebri) and indacaterol (Onbrez), and she has been using them for about nine months. Ms Breathless is otherwise healthy, and not taking any other medicines.

Predicting a new phase (T′′) of two-dimensional transition metal di-chalcogenides and strain-controlled topological phase transition

Single layered transition metal dichalcogenides have attracted tremendous research interest due to their structural phase diversities. By using a global optimization approach, we have discovered a new phase of transition metal dichalcogenides (labelled as T′′), which is confirmed to be energetically, dynamically and kinetically stable by our first-principles calculations. The new T′′ MoS2 phase exhibits an intrinsic quantum spin Hall (QSH) effect with a nontrivial gap as large as 0.42 eV, suggesting that a two-dimensional (2D) topological insulator can be achieved at room temperature. Most interestingly, there is a topological phase transition simply driven by a small tensile strain of up to 2%. Furthermore, all the known MX2 (M = Mo or W; X = S, Se or Te) monolayers in the new T′′ phase unambiguously display similar band topologies and strain controlled topological phase transitions. Our findings greatly enrich the 2D families of transition metal dichalcogenides and offer a feasible way to control the electronic states of 2D topological insulators for the fabrication of high-speed spintronics devices.

Two sympatric spotted gum species are molecularly homogeneous.

Large fruited spotted gum eucalypt Corymbia henryi occurs sympatrically with small fruited spotted gum Corymbia citriodora subspecies variegata over a large portion of its range on the east coast of Australia. The two taxa are interfertile, have overlapping flowering times and share a common set of insect and vertebrate pollinators. Previous genetic analysis of both taxa from two geographically remote sites suggested that the two were morphotypes rather than genetically distinct species. In this study we further explore this hypothesis of genic species by expanding sampling broadly through their sympatric locations and examine local-scale spatial genetic structure in stands that differ in species and age composition. Delineation of populations at five microsatellite loci, using an individual-based approach and Bayesian modelling, as well as clustering of individuals based on allele frequencies showed the two species to be molecularly homogeneous. Genetic structure aligned largely with geographic areas of origin, and followed an isolation-by-distance model, where proximal populations were generally less differentiated than more distant ones. At the stand level, spotted gums also generally showed little structure consistent with the high levels of gene flow inferred across the species range. Disturbances in the uniformity of structuring were detected, however, and attributed to localised events giving rise to even aged stands, probably due to regeneration from a few individuals following fire.

Changes in phosphine sorption in wheat after storage at two temperatures.

BACKGROUND: Wheat can be stored for many months before being fumigated with phosphine to kill insects, so a study was undertaken to investigate whether the sorptive capacity of wheat changes as it ages. Wheat was stored at 15 or 25C and 55% RH for up to 5.5 months, and samples were fumigated at intervals to determine sorption. Sealed glass flasks (95% full) were injected with 1.5 mg L-1 of phosphine based on flask volume. Concentrations were monitored for 11 days beginning 2 h after injection. Some wheat samples were refumigated after a period of ventilation. Several fumigations of wheat were conducted to determine the pattern of sorption during the first 24 h. RESULTS: Phosphine concentration declined exponentially with time from 2 h after injection. Rate of sorption decreased with time spent in storage at either 15 or 25C and 55% RH. Rate of sorption tended to be lower when wheat was refumigated, but this could be explained by time in storage rather than by refumigation per se. The data from the 24 h fumigations did not fit a simple exponential decay equation. Instead, there was a rapid decline in the first hour, with phosphine concentration falling much more slowly thereafter. CONCLUSIONS: The results have implications for phosphine fumigation of insects in stored wheat. Both the time wheat has spent in storage and the temperature at which it has been stored are factors that must be considered when trying to understand the impact of sorption on phosphine concentrations in commercial fumigations.

Structure and dynamics of two-dimensional sheared granular flows

The structure and dynamics of the two-dimensional linear shear flow of inelastic disks at high area fractions are analyzed. The event-driven simulation technique is used in the hard-particle limit, where the particles interact through instantaneous collisions. The structure (relative arrangement of particles) is analyzed using the bond-orientational order parameter. It is found that the shear flow reduces the order in the system, and the order parameter in a shear flow is lower than that in a collection of elastic hard disks at equilibrium. The distribution of relative velocities between colliding particles is analyzed. The relative velocity distribution undergoes a transition from a Gaussian distribution for nearly elastic particles, to an exponential distribution at low coefficients of restitution. However, the single-particle distribution function is close to a Gaussian in the dense limit, indicating that correlations between colliding particles have a strong influence on the relative velocity distribution. This results in a much lower dissipation rate than that predicted using the molecular chaos assumption, where the velocities of colliding particles are considered to be uncorrelated.

Complexes of lanthanide perchlorates with two new O,N,O ligands derived from antipyraldehyde and acetic and benzoic acid hydrazides

Antipyrine is a well known ligand for lanthanides (I). A forage through the organic literature of pyrazolones reveals that the 4-position of antipyrine is amenable to a wide variety of organic reactions. It should thus be possible to introduce suitable functional groups at this position and design new multidentate ligands for metal ions. It is also found that the coordination chemistry of lanthanides is much less well developed and far fewer ligands have been used for complexation with lanthanide ions compared to that of the d-transition metal ions. Keeping these points in view we have reported earlier, complexes of lanthanides with a bidentate ligand N,N-diethyl-antipyrine-4-carboxamide (2). In this communication we report the synthesis of two new ligands from Schiff base condensation of antipyraldehyde and the hydrazides of acetic and benzoic acids and the complexes formed by these hydrazones with lanthanide perchlorates.

Development of pseudo-two-dimensional turbulent wakes

Pseudotwo-dimensional wakes are generated by introducing spanwise cellular structures into an otherwise plane turbulent wake by means of the castellated blunt trailing edges of different configurations. The transverse growths of these coflowing cellular wakes are found to be independent of each other without any noticeable spanwise interaction. This wake growth is examined in the light of the plane equilibrium wake analysis. Though these wakes are not found to be exactly self-similar, their growth shows a nonmonotonous approach toward the asymptotic state appropriate to that of a plane wake. The dye emission in the wakes illustrated a coherent vortical structure in the transverse plane, similar to that of the usual two-dimensional wake, in spite of the initial spanwise irregularities.

Two couples including Willy Tese Moses and Gertrud Moses walking down a street; Bad Ragaz, Switzerland Portraits Couples

Digital Image

Fenja Rost with two unidentified men on a horse drawn cart working on a farm Portraits Groups

Digital Image

Myelodysplasia as a cause of hindlimb ataxia in two beef calves.

Myelodysplasia is a general term referring to abnormal development of the spinal cord. Unless associated with vertebral malformations, it can be difficult to distinguish clinically from other causes of spinal cord disease. These case reports describe the clinical and pathological findings in two calves with a distinctive non-progressive pelvic limb ataxia. The syndrome was observed in two calves on a large, extensively managed beef cattle property near Richmond, north Queensland. Both calves had similar clinical signs, including hindlimb ataxia with swaying of the pelvis and a well-coordinated bilateral hopping-like action. The differential diagnoses are discussed. A focal or diffuse myelodysplasia should be suspected in calves that have exhibited a non-progressive hindlimb ataxia from birth.

Understanding invasion history: genetic structure and diversity of two globally invasive plants and implications for their management

Aim: Resolving the origin of invasive plant species is important for understanding the introduction histories of successful invaders and aiding strategies aimed at their management. This study aimed to infer the number and origin(s) of introduction for the globally invasive species, Macfadyena unguis-cati and Jatropha gossypiifolia using molecular data. Location: Native range: Neotropics; Invaded range: North America, Africa, Europe, Asia, Pacific Islands and Australia. Methods: We used chloroplast microsatellites (cpSSRs) to elucidate the origin(s) of introduced populations and calculated the genetic diversity in native and introduced regions. Results: Strong genetic structure was found within the native range of M. unguis-cati, but no genetic structuring was evident in the native range of J. gossypiifolia. Overall, 27 haplotypes were found in the native range of M. unguis-cati. Only four haplotypes were found in the introduced range, with more than 96% of introduced specimens matching a haplotype from Paraguay. In contrast, 15 haplotypes were found in the introduced range of J. gossypiifolia, with all invasive populations, except New Caledonia, comprising multiple haplotypes. Main conclusions: These data show that two invasive plant species from the same native range have had vastly different introduction histories in their non-native ranges. Invasive populations of M. unguis-cati probably came from a single or few independent introductions, whereas most invasive J. gossypiifolia populations arose from multiple introductions or alternatively from a representative sample of genetic diversity from a panmictic native range. As introduced M. unguis-cati populations are dominated by a single haplotype, locally adapted natural enemies should make the best control agents. However, invasive populations of J. gossypiifolia are genetically diverse and the selection of bio-control agents will be considerably more complex.

Freddy Godshaw (Gottschalk) (far left) on Pfingsten (Pentacost) with two unidentified friends who perished in the Holocaust. Portraits Children

Digital Image