Bacillus thuringiensis resistance in Plutella – too many trees?

Plutella xylostella was the first insect for which resistance to Bacillus thuringiensis was reported in the field, yet despite many studies on the nature of this resistance phenotype its genetic and molecular basis remains elusive. Many different factors have been proposed as contributing to resistance, although in many cases it has not been possible to establish a causal link. Indeed, there are so many studies published that it has become very difficult to “see the wood for the trees”. This article will attempt to clarify our current understanding of Bt resistance in P. xylostella and consider the criteria that are used when validating a particular model

Donating to Destruction: Combating Capacity Enhancing Fisheries Subsidies and EEZ Overfishing Within UNCLOS

The delicate balance on which the oceans now sit cannot be understated. While many oceanic issues persist, overfishing is one that affects large portions of the Earth's population, particularly in relation to food. Despite a growing decline in fisheries populations, governments continue to subsidize their fisheries at alarming rates. This issue is currently at the forefront of WTO negotiations, but has it been overlooked within the scope of UNCLOS? Despite a strong exclusion clause for domestic EEZ fisheries, perhaps reframing a potential dispute as contrary to protection and preservation of the marine environment, instead of one solely rooted in fisheries, might provide an avenue for meaningful change, if a dispute were to arise

Analysis of a cell division gene cluster in "Escherichia coli"

Several genes, essential for cell growth and division in Escherichia coli, have been mapped to the 76 minute region of the chromosome. DNA sequencing of part of this region revealed three cell division genes (ftsY, ftsE, and ftsX) in a putative operon. A fourth gene (orf4) was also identified that was transcribed in the opposite direction to the putative operon. The genes rpof, f am, dnaM and ftsS have also been mapped to this region, but their location, relative to the putative operon, was unknown. In this study the fam and rpoU genes were independently cloned and shown to be allelic. The dnaM gene was also found to be an allele of rpoH, and the gene was found to lie immediately downstream of the putative cell division operon. The restriction map of the area was extended, and the distance between the putative operon and the nearest known gene clockwise on the chromosome map (pit), was determined. The ftsS gene was found to be an allele of ftsX. Two promoters were identified within the putative operon, one proximal to ftsY and the other proximal to ftsE. A combination of S1 and primer extension mapping, of the mRNA transcripts, identified the transcriptional start sites of these two promoters. A polycistronic message was also identified encoding all three cell division genes, suggesting at least some degree of co-ordinated expression. In conclusion, the transcriptional organisation of the 76 minute, essential gene cluster has been determined, and evidence has been presented. that there is some degree of co-ordinated expression of the component genes

Structural classification of insecticidal proteins – towards an in silico characterization of novel toxins

The increasing rate of discovery of new toxins with potential for the control of invertebrate pests through next generation sequencing, presents challenges for the identification of the best candidates for further development. A consideration of structural similarities between the different toxins suggest that they may be functionally less diverse than their low sequence similarities might predict. This is encouraging from the prospective of being able to use computational tools to predict toxin targets from their sequences, however more structure/function data are still required to reliably inform such predictions

Glabralysins, potential New β-pore-forming toxin family members from the schistosomiasis vector snail biomphalaria glabrata

Biomphalaria glabrata is a freshwater Planorbidae snail. In its environment, this mollusk faces numerous microorganisms or pathogens, and has developed sophisticated innate immune mechanisms to survive. The mechanisms of recognition are quite well understood in Biomphalaria glabrata, but immune effectors have been seldom described. In this study, we analyzed a new family of potential immune effectors and characterized five new genes that were named Glabralysins. The five Glabralysin genes showed different genomic structures and the high degree of amino acid identity between the Glabralysins, and the presence of the conserved ETX/MTX2 domain, support the hypothesis that they are pore-forming toxins. In addition, tertiary structure prediction confirms that they are structurally related to a subset of Cry toxins from Bacillus thuringiensis, including Cry23, Cry45, and Cry51. Finally, we investigated their gene expression profiles in snail tissues and demonstrated a mosaic transcription. We highlight the specificity in Glabralysin expression following immune stimulation with bacteria, yeast or trematode parasites. Interestingly, one Glabralysin was found to be expressed in immune-specialized hemocytes, and two others were induced following parasite exposure

Prospecting for scarabid specific Bacillus thuringiensis crystal toxin cry8 gene in sugarcane ecosystem of Tamil Nadu, India

In the present study, we report the occurrence of cry8 positive isolates of Bacillus thuringiensis (Bt) in selected white grub, Holotrichia serrata F. (Coleoptera: Scarabaeidae), endemic soils of sugarcane ecosystem and other places in Tamil Nadu. Out of the 66 soil samples collected and screened for white grub specific Bt, 74 isolates of the bacterium, all containing only spherical crystal toxin, were identified. PCR screening of these isolates with cry8 gene universal primer revealed six isolates to be positive. Further, the amplicon of a 370 bp band, amplified with another set of degenerate primer designed based on the conserved sequence of cry8 genes, was sequenced from four isolates. Multiple sequence alignment revealed the gene sequences to be the same for all the isolates. The present report of the availability of cry8 positive Bt isolates opens the avenue for controlling white grubs through transgenic research

Quantum elimination measurements

If an initial state is prepared from a known set, then the aim of a quantum state elimination measurement is to rule out a subset of the possible initial states. We use semi-definite programming to find either bounds or exact results on the success probabilities of certain elimination measurements. In conjunction we use an analytic approach to find optimal measurements. We obtain optimal measurements for unambiguous elimination in a two-qubit case where each qubit is in one of two possible states. We also show how it might be possible to use our elimination measurements in a QKD protocol. In addition we prove that the best method to eliminate the highest average number of states for sequences of qubits with each qubit in one of two possible states is individual unambiguous measurements. Furthermore we show the method of decomposing a unitary matrix into beamsplitter-like operations found by Reck et al. and apply this to our elimination measurement to realise a way of experimental implementation. In the final chapter we look at joint measurements and find the optimal probe state that we would use to minimise the uncertainty in our estimation of the sharpness of a measurement between two observables.Engineering and Physical Sciences Research Council (EPSRC) funding

Polybenzoxazine-Grafted Composites: Accelerated Polymerization of Benzoxazine Resins from Bulk- to Microscale Mesylated Materials

Benzoxazine-based resins often afford high modulus and high glass transition polymers that are desirable for creating safe and reliable thermoset parts and composites. However, benzoxazine resins have had limited widespread deployment into industry due to their high cure temperature. By blending functionalized glass substrates with the benzoxazine monomer, we hypothesize that the cure temperature of thermosetting resin can be lowered. The structure and purity of the particles, determined by NMR and FTIR, will be presented. DSC studies on the stability and cure accelerating properties of blends composed of functionalized glass substrates and benzoxazine monomer will be determined and compared against blends composed of un-functionalized glass substrates and a benzoxazine monomer. TGA studies for thermal stability of silica particles will also be discussed. The extent of functionalization of the silica will be studied via TGA and XPS. The application of this science may be used as an alternative to the current phenolic resins used in the aerospace industry

The relationship between patient satisfaction and patient-and family-centered care

Evidence of quality care is an important outcome in healthcare. Patient satisfaction, an outcome of care, is considered by many experts to be a measure of quality. Patient- and family-centered care (PFCC) is a healthcare delivery model that aims to enhance partnerships with healthcare providers and patients and families. These partnerships are believed to play a significant role in improving satisfaction and quality. However, there is a scarcity of research that uses standardized tools and methods to show correlations between patient satisfaction and PFCC.   The purpose of this study was to examine the relationship between the patient's perception of patient- and family-centered care (PFCC) as measured by questions defined by the National Task Force on Patient- and Family-Centered Care Metrics for Press Ganey Survey items and the patients' perception of their inpatient care as measured by the HCAHPS Inpatient Core Survey in patient care units in an academic medical center in the southeastern United States.   A descriptive cross-sectional research design was used. The sample (N=1016) was primarily white (57%) females (69%) with a mean age of 52.8 years. Those respondents that were highly satisfied with their care also rated their perception of the presence of PFCC highly. A relationship was also noted with respondent characteristics such as age, gender, and perceived health status. Significant relationships were noted with domains of care in which nurses had the most influence. Findings from this study validated relationships between patient satisfaction and PFCC and provided evidence that nurses play a vital role in this outcome.  Ph.D

The human cancer cell active toxin Cry41Aa from Bacillus thuringiensis acts like its insecticidal counterparts

Understanding how certain protein toxins from the normally insecticidal bacterium Bacillus thuringiensis (Bt) target human cell lines has implications for both the risk assessment of products containing these toxins and potentially for cancer therapy. This understanding requires knowledge of whether the human cell active toxins work by the same mechanism as their insecticidal counterparts or by alternative ones. The Bt Cry41Aa (also known as Parasporin3) toxin is structurally related to the toxins synthesised by commercially produced transgenic insect-resistant plants, with the notable exception of an additional C-terminal β-trefoil ricin domain. To better understand its mechanism of action, we developed an efficient expression system for the toxin and created mutations in regions potentially involved in the toxic mechanism. Deletion of the ricin domain did not significantly affect the activity of the toxin against the human HepG2 cell line, suggesting that this region was not responsible for the mammalian specificity of Cry41Aa. Various biochemical assays suggested that unlike some other human cell active toxins from Bt Cry41Aa did not induce apoptosis, but that its mechanism of action was consistent with that of a pore-forming toxin. The toxin induced a rapid and significant decrease in metabolic activity. Adenosine triphosphate depletion, cell swelling and membrane damage were also observed. An exposed loop region believed to be involved in receptor binding of insecticidal Cry toxins was shown to be important for the activity of Cry41Aa against HepG2 cells