A PCR-based method to distinguish fungi of the rice sheath-blight complex, Rhizoctonia solani, R. oryzae and R. oryzae-sativae

Identification of Rhizoctonia solani, R. oryzae and R. oryzae-sativae, components of the rice sheath disease complex, is extremely difficult and often inaccurate and as a result may hinder the success of extensive breeding programmes throughout Asia. In this study, primers designed from unique regions within the rDNA internal transcribed spacers have been used to develop a rapid PCR-based diagnostic test to provide an accurate identification of the species on rice. Tests on the specificity of the primers concerned showed that they provide the means for accurate identification of the Rhizoctonia species responsible for sheath diseases in rice.

Measurement of the full stress tensor in a crystal using photoluminescence from point defects: The example of nitrogen vacancy centers in diamond

We introduce a method for measuring the full stress tensor in a crystal utilising the properties of individual point defects. By measuring the perturbation to the electronic states of three point defects with C 3 v symmetry in a cubic crystal, sufficient information is obtained to construct all six independent components of the symmetric stress tensor. We demonstrate the method using photoluminescence from nitrogen-vacancy colour centers in diamond. The method breaks the inverse relationship between spatial resolution and sensitivity that is inherent to existing bulk strain measurement techniques, and thus, offers a route to nanoscale strain mapping in diamond and other materials in which individual point defects can be interrogated.

Lamina propria: The functional center of the bladder?

The bladder mucosa consists of the urothelium, basement membrane, and lamina propria (LP). Although the urothelium has been given much attention, it may be regarded as one part of a signaling system involving another equally important component of the bladder mucosa, namely, the LP. The LP lies between the basement membrane of the mucosa and the detrusor muscle and is composed of an extracellular matrix containing several types of cells, including fibroblasts, adipocytes, interstitial cells, and afferent and efferent nerve endings. In addition, the LP contains a rich vascular network, lymphatic vessels, elastic fibers, and smooth muscle fascicles (muscularis mucosae). The roles of the LP and its components in bladder function have not been definitively established, though it has been suggested to be the capacitance layer of the bladder, determining bladder compliance and enabling adaptive changes to increasing volumes. However, the bladder LP may also serve as a communication center, with an important integrative role in signal transduction to the central nervous system (nociception, mechanosensation). The LP may also, by means of its different components, make it possible for the urothelium to transmit information to other components of the bladder wall, contributing to activation of the detrusor muscle. In addition, the LP may serve as a source for production of factors influencing the growth of both the overlying urothelium and the underlying detrusor muscle.

A Novel Bradykinin-Related Dodecapeptide (RVALPPGFTPLR) from the Skin Secretion of the Fujian Large-Headed Frog (Limnonectes fujianensis) Exhibiting Unusual Structural and Functional Features

Bradykinin-related peptides (BRPs) are significant components of the defensive skin secretions of many anuran amphibians, and these secretions represent the source of the most diverse spectrum of such peptides so far encountered in nature. Of the many families of bioactive peptides that have been identified from this source, the BRPs uniquely appear to represent homologues of counterparts that have specific distributions and receptor targets within discrete vertebrate taxa, ranging from fishes through mammals. Their broad spectra of actions, including pain and inflammation induction and smooth muscle effects, make these peptides ideal weapons in predator deterrence. Here, we describe a novel 12-mer BRP (RVALPPGFTPLR-RVAL-(L1, T6, L8)-bradykinin) from the skin secretion of the Fujian large-headed frog (Limnonectes fujianensis). The C-terminal 9 residues of this BRP (-LPPGFTPLR) exhibit three amino acid substitutions (L/R at Position 1, T/S at Position 6 and L/F at Position 8) when compared to canonical mammalian bradykinin (BK), but are identical to the kinin sequence present within the cloned kininogen-2 from the Chinese soft-shelled turtle (Pelodiscus sinensis) and differ from that encoded by kininogen-2 of the Tibetan ground tit (Pseudopodoces humilis) at just a single site (F/L at Position 8). These data would imply that the novel BRP is an amphibian defensive agent against predation by sympatric turtles and also that the primary structure of the avian BK, ornithokinin (RPPGFTPLR), is not invariant within this taxon. Synthetic RVAL-(L1, T6, L8)-bradykinin was found to be an antagonist of BK-induced rat tail artery smooth muscle relaxation acting via the B2-receptor.

Measurement of the Electrogenicity of Bile Salt/H+ Antiport in Escherichia coli

The transmembrane proton gradient (ΔpH) is the primary source of energy exploited by secondary active substrate/H+ antiporters to drive the electroneutral transport of substrates across the Escherichia coli (E. coli) inner membrane. Such electroneutral transport results in no net movement of charges across the membrane. The charge on the transported substrate and the stoichiometry of the exchange reaction, however, can result in an electrogenic reaction which is driven by both the ΔpH and the electrical (∆Ψ) components of the proton electrochemical gradient, resulting in a net movement of electrical charges across the membrane. We have shown that the major facilitator superfamily transporter MdtM - a multidrug efflux protein from E. coli that functions physiologically in protection of bacterial cells against bile salts - imparts bile salt resistance to the bacterial cell by coupling the exchange of external protons (H+) to the efflux of bile salts from the cell interior via an electrogenic antiport reaction (Paul et al., 2014). This protocol describes, using fluorometry, how to detect electrogenic antiport activity of MdtM in inverted membrane vesicles of an antiporter-deficient strain of E. coli TO114 cells by measuring transmembrane ∆Ψ. The method exploits changes that occur in the intensity of the fluorescence signal (quenching and dequenching) of the probe Oxonol V in response to changes in membrane potential due to the MdtM-catalysed sodium cholate/H+ exchange reaction. The protocol can be adapted to detect activity of any secondary active antiporter that couples the electrogenic translocation of H+ across a biological membrane to that of its counter-substrate, and may be used to unmask otherwise camouflaged transport activities and physiological roles.

Asthma control and exacerbations: two different sides of the same coin.

Purpose of review: Optimal asthma management includes both the control of asthma symptoms and reducing the risk of future asthma exacerbations. Traditionally, treatment has been adjusted largely on the basis of symptoms and lung function and for many patients, this approach delivers both excellent symptom control and reduced risk. However, the relationship between these two key components of the disease may vary between different asthmatic phenotypes and disease severities and there is increasing recognition of the need for more individualized treatment approaches.

Recent findings: A number of factors which predict exacerbation risk have been identified including demographic and behavioural features and specific inflammatory biomarkers. Type-2 cytokine-driven eosinophilic airways inflammation predisposes to frequent exacerbations and predicts response to corticosteroids, and the usefulness of sputum eosinophilia as both a marker of exacerbation risk and biomarker for adjustment of corticosteroid treatment has been established for some time. However, attempts to develop surrogate markers, which would be more straightforward to deliver in the clinic, have been challenging.

Summary: Some patients with asthma have persistent symptoms in the absence of type-2 cytokine driven-eosinophilic airways inflammation due to noncorticosteroid responsive mechanisms (T2-low disease). Composite biomarker strategies using easily measured surrogate indicators of type-2 inflammation (such as fractional exhaled nitric oxide, blood eosinophil count and serum periostin levels) may predict exacerbation risk better but it is unclear if they can be used to adjust corticosteroid treatment. Biomarkers will be used to target novel biologic treatments but additionally may be used to optimize corticosteroid treatment dose and act as prognostics for exacerbation risk and potentially other important longer term asthma outcomes.

'Trusting the numbers': mineral prospecting, raising finance and the governance of knowledge

Mineral prospecting and raising finance for ‘junior’ mining firms has historically been regarded as a speculative activity. For the regulators of securities markets upon which ‘junior’ mining companies seek to raise capital, a perennial problem has been handling not only the indeterminacy of scientific claims, but also the social basis of epistemic practices. This paper examines the production of a system of public warrant and associated knowledge practices intended to enable investors to differentiate between ‘destructive’ and ‘productive’ varieties of financial speculation. It traces the use of the notion of ‘disclosure’ in constructing and legitimizing the ‘juniors’ market in Canada. It argues that though the work of ‘economics’ may be necessary in the construction of markets, it is by no means sufficient. Attention must also be given to the ways in which legal models of ‘the free-market’ can be translated and constantly re-worked across the sites and spaces of regulatory practice, animating the geographies of markets.

'Trusting the numbers': mineral prospecting, raising finance and the governance of knowledge

Mineral prospecting and raising finance for ‘junior’ mining firms has historically been regarded as a speculative activity. For the regulators of securities markets upon which ‘junior’ mining companies seek to raise capital, a perennial problem has been handling not only the indeterminacy of scientific claims, but also the social basis of epistemic practices. This paper examines the production of a system of public warrant and associated knowledge practices intended to enable investors to differentiate between ‘destructive’ and ‘productive’ varieties of financial speculation. It traces the use of the notion of ‘disclosure’ in constructing and legitimizing the ‘juniors’ market in Canada. It argues that though the work of ‘economics’ may be necessary in the construction of markets, it is by no means sufficient. Attention must also be given to the ways in which legal models of ‘the free-market’ can be translated and constantly re-worked across the sites and spaces of regulatory practice, animating the geographies of markets.