Particle-unstable light nuclei with a Sturmian approach that preserves the Pauli principle

Sturmian theory for nucleon-nucleus scattering is discussed in the presence of all the phenomenological ingredients necessary for the description of weakly-bound (or particle-unstable) light nuclear systems. Currently, we use a macroscopic potential model of collective nature. The analysis shows that the couplings to low-energy collective-core excitations are fundamental but they are physically meaningful only if the constraints introduced by the Pauli principle are taken into account. The formalism leads one to discuss a new concept, Pauli hindrance, which appears to be important to understand the structure of weakly-bound and unbound systems.Comment: 5 pages, 2 figures, 1 table, contribution to proceedings of "18th International IUPAP Conference on Few-Body Problems in Physics," Santos, Brazil, August 21-26, 200

Linking the exotic structure of 17{}^{17}C to its unbound mirror 17{}^{17}Na

The structure of ${}^{17}$C is used to define a nuclear interaction that, when used in a multichannel algebraic scattering theory for the $n+{}^{16}$C system, gives a credible definition of the (compound) excitation spectra. When couplings to the low-lying collective excitations of the ${}^{16}$C-core are taken into account, both sub-threshold and resonant states about the $n+{}^{16}$C threshold are found. Adding Coulomb potentials to that nuclear interaction, the method is used for the mirror system of $p+{}^{16}$Ne to specify the low-excitation spectrum of the particle unstable $^{17}$Na. We compare the results with those of a microscopic cluster model. A spectrum of low excitation resonant states in ${}^{17}$Na is found with some differences to that given by the microscopic-cluster model. The calculated resonance half-widths (for proton emission) range from $\sim 2$ to $\sim 672$ keV.Comment: 13 pages, 5 figure

Wei Fan v South Eastern Sydney Local Health District (No 2)

Wei Fan v South Eastern Sydney Local Health District (No 2)1 is a professional negligence decision given by Harrison AsJ on 31 August 2015. In this case, the plaintiff claimed damages for medical negligence on the basis of delayed diagnoses which caused him significant injuries. This case serves as a good example of the importance of credible lay and expert evidence, particularly where the facts include multiple hospitals and multiple admissions. This case also provides a reasonable example of the interplay between different mitigating defences including contributory negligence, failure to mitigate and volenti non fit injuria (voluntary assumption of risk). Ultimately, as the plaintiff’s evidence was not substantial or credible, the plaintiff’s claim failed. The court also went further and determined that (had the plaintiff been successful) there would have been a non-specific discount for contributory negligence

Non-localities in nucleon-nucleus potentials

Two causes of non-locality inherent in nucleon-nucleus scattering are considered. They are the results of two-nucleon antisymmetry of the projectile with each nucleon in the nucleus and the dynamic polarization potential representation of channel coupling. For energies $\sim 40 - 300$ MeV, a g-folding model of the optical potential is used to show the influence of the knock-out process that is a result of the two-nucleon antisymmetry. To explore the dynamic polarization potential caused by channel coupling, a multichannel algebraic scattering model has been used for low-energy scattering.Comment: 12 pages, 11 figures, submitted to EPJ

Coupled-channel calculation of bound and resonant spectra of Lambda-9Be and Lambda-13C hypernuclei

A Multi-Channel Algebraic Scattering (MCAS) approach has been used to analyze the spectra of two hyper-nuclear systems, Lambda-9Be and Lambda-13C. The splitting of the two odd-parity excited levels (1/2^- and 3/2^-) at 11 MeV excitation in Lambda-13C is driven mainly by the weak Lambda-nucleus spin-orbit force, but the splittings of the 3/2^+ and 5/2^+ levels in both Lambda-9Be and Lambda-13C have a different origin. These cases appear to be dominated by coupling to the collective 2+ states of the core nuclei. Using simple phenomenological potentials as input to the MCAS method, the observed splitting and level ordering in Lambda-9Be is reproduced with the addition of a weak spin-spin interaction acting between the hyperon and the spin of the excited target. With no such spin-spin interaction, the level ordering in Lambda-9Be is inverted with respect to that currently observed. In both hyper-nuclei, our calculations suggest that there are additional low-lying resonant states in the Lambda-nucleus continua.Comment: 15 pages, 3 figures, 6 tables. To be published in International Journal of Modern Physics

Transcriptional cellular responses in midgut tissue of Aedes aegypti larvae following intoxication with Cry11Aa toxin from Bacillus thuringiensis.

BackgroundAlthough much is known about the mechanism of action of Bacillus thuringiensis Cry toxins, the target tissue cellular responses to toxin activity is less understood. Previous transcriptomic studies indicated that significant changes in gene expression occurred during intoxication. However, most of these studies were done in organisms without a sequenced and annotated reference genome. A reference genome and transcriptome is available for the mosquito Aedes aegypti, and its importance as a disease vector has positioned its biological control as a primary health concern. Through RNA sequencing we sought to determine the transcriptional changes observed during intoxication by Cry11Aa in A. aegypti and to analyze possible defense and recovery mechanisms engaged after toxin ingestion.ResultsIn this work the changes in the transcriptome of 4(th) instar A. aegypti larvae exposed to Cry11Aa toxin for 0, 3, 6, 9, and 12 h were analyzed. A total of 1060 differentially expressed genes after toxin ingestion were identified with two bioconductoR packages: DESeq2 and EdgeR. The most important transcriptional changes were observed after 9 or 12 h of toxin exposure. GO enrichment analysis of molecular function and biological process were performed as well as Interpro protein functional domains and pBLAST analyses. Up regulated processes include vesicular trafficking, small GTPase signaling, MAPK pathways, and lipid metabolism. In contrast, down regulated functions are related to transmembrane transport, detoxification mechanisms, cell proliferation and metabolism enzymes. Validation with RT-qPCR showed large agreement with Cry11Aa intoxication since these changes were not observed with untreated larvae or larvae treated with non-toxic Cry11Aa mutants, indicating that a fully functional pore forming Cry toxin is required for the observed transcriptional responses.ConclusionsThis study presents the first transcriptome of Cry intoxication response in a fully sequenced insect, and reveals possible conserved cellular processes that enable larvae to contend with Cry intoxication in the disease vector A. aegypti. We found some similarities of the mosquito responses to Cry11Aa toxin with previously observed responses to other Cry toxins in different insect orders and in nematodes suggesting a conserved response to pore forming toxins. Surprisingly some of these responses also correlate with transcriptional changes observed in Bti-resistant and Cry11Aa-resistant mosquito larvae

Complex Conjugate Pairs in Stationary Sturmians

Sturmian eigenstates specified by stationary scattering boundary conditions are particularly useful in contexts such as forming simple separable two nucleon t matrices, and are determined via solution of generalised eigenvalue equation using real and symmetric matrices. In general, the spectrum of such an equation may contain complex eigenvalues. But to each complex eigenvalue there is a corresponding conjugate partner. In studies using realistic nucleon--nucleon potentials, and in certain positive energy intervals, these complex conjugated pairs indeed appear in the Sturmian spectrum. However, as we demonstrate herein, it is possible to recombine the complex conjugate pairs and corresponding states into a new, sign--definite pair of real quantities with which to effect separable expansions of the (real) nucleon--nucleon reactance matrices.Comment: (REVTEX) 8 Pages, Padova DFPD 93/TH/78 and University of Melbourn