Raman depolarization ratios in RNA and DNA are sensitive for sugar-base coupling

Polarized and depolarized Raman spectra are obtained for a number of synthetic polynucleotides containing adenine, uracil, and thymine bases. The depolarization ratios are determined by two methods: (1) by dividing the -spectrum by the -spectrum and (2) after curve fitting. Overlapping bands, isotope splitting, reorientational broadening, and noncoincidence splitting affect the magnitude of the depolarization ratios over the band-width. For both Lorentz and Gauss curves these influences are simulated. A comparison of the Raman spectra of RNA and DNA molecules shows that the depolarization ratios for a number of similar base vibrations are different. The vibrational modes and the depolarization ratios of sugar vibrations are most sensitive to the structure of the polynucleotide. Base vibrations that have their potential energy distributed over base and sugar atoms also seem to be more sensitive to the structure. For instance the adenine vibrations at 1332 cm-1 and 1344 cm-1 in poly(dA), poly(dA) · poly(dT) and poly(dA-dT) · poly(dA-dT) have different depolarization ratios of, respectively, 0.36 and 0.28. This supports a previous assignment of the 1332 cm-1 band to a different sugar pucker (O4,-endo) than the C2,-endo corresponding with the 1344 cm-1 vibration. Assuming equal Raman scattering coefficients for this vibration, irrespective of the sugar pucker gives rise to the following ratio of the O4,-endo/C2,-endo in poly(dA) of 0.41, in poly(dA) · poly(dT) of 0.37, and in poly(dA-dT) · poly(dA-dT) of 0.41

Sedation for Gastrointestinal Endoscopic Procedures in the Elderly: Getting Safer but Still Not Nearly Safe Enough

Previously published UK reports showed that excessively large doses of benzodiazepines and opiates were being commonly used to sedate elderly patients for gastrointestinal (GI) endoscopy. This unsafe practice has lead to avoidable morbidity and mortality. We have taken the opportunity provided by recent reports to examine whether GI endoscopy sedation practice in the elderly has improved in the light of this evidence and the publication of guidelines in which specific recommendations on sedation dosage are given

Unstable Identities: The European Court of Human Rights and the Margin of Appreciation

All legal systems work under a master narrative – the self-conception of most actors of the system itself. A master narrative is a short and simple story and it is the underlying premise upon which any legal system is based. It is a simple story because it paints the system in quick broad brushstrokes and at (most) times is oblivious to the paradoxes within it. Furthermore, a master narrative is important for legitimization purposes because the actors’ legitimacy will depend on their (perceived) conformity with the system’s master narrative. Therefore, legitimacy is self-referential; the yardsticks for a legitimate action are contained within the system’s master narrative, not outside of it. When talking about different international courts it is important to remember that they are embedded within a master narrative that is contextual and contingent and, at different points, more or less contested. This paper explores the question of what happens when the master-narrative is in a period of transition (from a state cantered to a post-national world order) and when the actors’ legitimacy, their interpretative endeavours the very fundamentals are in a state of flux. I use the margin of appreciation discussion as a focal point of describing the conflicting narratives under which the European Court of Human Rights works, narratives in which the different actors (judges, attorneys, NGO activists, government agents) and their consequences in terms of the interpretation of the European Convention on Human Rights

Organochlorines in common dolphins caught in shark nets during the Natal ‘sardine run’

The concentrations of organochlorines were determined in blubber and liver samples from common dolphins inhabiting the coastal waters of the south-east coast of southern Africa. Liver levels of PCBs and DDTs are far lower and do not appear directly associated with those in blubber. In males, blubber residue concentrations increased with age but in females a marked rapid decline in concentrations of PCBs and t-DDT was evident between the eighth and eleventh growth layer groups, approximately the age of sexual maturity and subsequent to their first or second ovulation. Lower levels in females are explained through transfer to the new-born calf during lactation and the consequences of this for the newborn calf are discussed

Nonsingular, big-bounce cosmology from spinor-torsion coupling

The Einstein-Cartan-Sciama-Kibble theory of gravity removes the constraint of general relativity that the affine connection be symmetric by regarding its antisymmetric part, the torsion tensor, as a dynamical variable. The minimal coupling between the torsion tensor and Dirac spinors generates a spin-spin interaction which is significant in fermionic matter at extremely high densities. We show that such an interaction averts the unphysical big-bang singularity, replacing it with a cusp-like bounce at a finite minimum scale factor, before which the Universe was contracting. This scenario also explains why the present Universe at largest scales appears spatially flat, homogeneous and isotropic.Comment: 7 pages; published versio

Enhanced diffraction by a rectangular grating made of a negative phase--velocity (or negative index) material

The diffraction of electromagnetic plane waves by a rectangular grating formed by discrete steps in the interface of a homogeneous, isotropic, linear, negative phase--velocity (negative index) material with free space is studied using the semi--analytic C method. When a nonspecular diffracted order is of the propagating type, coupling to that order is significantly larger for a negative index material than for conventional material. The computed coupling strengths reported here are in agreement with recent experiments, and illustrate the role of evanescent fields localized at the grating interface in producing this enhanced coupling.Comment: 12 pages, 4 figure

Stochastic signatures of involuntary head micro-movements can be used to classify females of ABIDE into different subtypes of neurodevelopmental disorders.

© 2017 Torres, Mistry, Caballero and Whyatt. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).Background: The approximate 5:1 male to female ratio in clinical detection of Autism Spectrum Disorder (ASD) prevents research from characterizing the female phenotype. Current open access repositories [such as those in the Autism Brain Imaging Data Exchange (ABIDE I-II)] contain large numbers of females to help begin providing a new characterization of females on the autistic spectrum. Here we introduce new methods to integrate data in a scale-free manner from continuous biophysical rhythms of the nervous systems and discrete (ordinal) observational scores. Methods: New data-types derived from image-based involuntary head motions and personalized statistical platform were combined with a data-driven approach to unveil sub-groups within the female cohort. Further, to help refine the clinical DSM-based ASD vs. Asperger's Syndrome (AS) criteria, distributional analyses of ordinal score data from Autism Diagnostic Observation Schedule (ADOS)-based criteria were used on both the female and male phenotypes. Results: Separate clusters were automatically uncovered in the female cohort corresponding to differential levels of severity. Specifically, the AS-subgroup emerged as the most severely affected with an excess level of noise and randomness in the involuntary head micro-movements. Extending the methods to characterize males of ABIDE revealed ASD-males to be more affected than AS-males. A thorough study of ADOS-2 and ADOS-G scores provided confounding results regarding the ASD vs. AS male comparison, whereby the ADOS-2 rendered the AS-phenotype worse off than the ASD-phenotype, while ADOS-G flipped the results. Females with AS scored higher on severity than ASD-females in all ADOS test versions and their scores provided evidence for significantly higher severity than males. However, the statistical landscapes underlying female and male scores appeared disparate. As such, further interpretation of the ADOS data seems problematic, rather suggesting the critical need to develop an entirely new metric to measure social behavior in females. Conclusions: According to the outcome of objective, data-driven analyses and subjective clinical observation, these results support the proposition that the female phenotype is different. Consequently the “social behavioral male ruler” will continue to mask the female autistic phenotype. It is our proposition that new observational behavioral tests ought to contain normative scales, be statistically sound and combined with objective data-driven approaches to better characterize the females across the human lifespan.Peer reviewe