Reconstruction of optical vector-fields with applications in endoscopic imaging

We introduce a framework for the reconstruction of the amplitude, phase and polarisation of an optical vector-field using measurements acquired by an imaging device characterised by an integral transform with an unknown spatially-variant kernel. By incorporating effective regularisation terms, this new approach is able to recover an optical vector-field with respect to an arbitrary representation system, which may be different from the one used for device calibration. In particular, it enables the recovery of an optical vector-field with respect to a Fourier basis, which is shown to yield indicative features of increased scattering associated with tissue abnormalities. We demonstrate the effectiveness of our approach using synthetic holographic images as well as biological tissue samples in an experimental setting where measurements of an optical vector-field are acquired by a multicore fibre (MCF) endoscope, and observe that indeed the recovered Fourier coefficients are useful in distinguishing healthy tissues from tumours in early stages of oesophageal cancer.M. Gataric and S. E. Bohndiek were supported by an EPSRC grant EP/N014588/1 for the centre for Mathematical and Statistical Analysis of Multimodal Clinical Imaging. G. S. D. Gordon and S. E. Bohndiek received funding from CRUK (C47594/A16267, C14303/A17197, C47594/A21102) and a pump-priming award from the Cancer Research UK Cambridge Centre Early Detection Programme (A20976). The work of F. Renna was funded in part by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 655282 and in part by the FCT grant SFRH/BPD/118714/2016

A Stokes polarimetric light microscopy view of liquid crystal droplets

The optical characteristics of materials, such as their magnetooptical effects, birefringence, optical activities, linear and circular dichroism, are probed via the polarisation states of light transmitted through or reflected from the specimens. As such, the measurements of the polarisation states play an important role in many research disciplines. Experimentally, Stokes parameters provide a full description of the polarisation states of light. We report the implementation of a dual- photoelastic modulator based polarimeter in a light microscope, enabling the determination of Stokes parameters at each pixel. As a case study, polarimetric images of liquid crystal droplets of different internal structures are obtained, showing their distinct polarisation characteristics. We demonstrate that the prototype Stokes polarimetric microscope allows the quantitative determination of the polarisation characteristics of light at the object plane and enables the access of the information of full polarisation states as compared to a conventional cross polariser microscope. This work shows that Stokes polarimetric microscopy may find potential applications in a wide range of research fields

Rho decay width from the lattice

The XXVIII International Symposium on Lattice Field Theory, June 14-19, 2010, Villasimius, Sardinia ItalyInternational audienceWhile the masses of light hadrons have been extensively studied in lattice QCD simulations, there exist only a few exploratory calculations of the strong decay widths of hadronic resonances. We will present preliminary results of a computation of the rho meson width obtained using $N_f=2+1$ flavor simulations. The work is based on L\"uscher's formalism and its extension to moving frames

Regularity of Edge Ideals and Their Powers

We survey recent studies on the Castelnuovo-Mumford regularity of edge ideals of graphs and their powers. Our focus is on bounds and exact values of $\text{ reg } I(G)$ and the asymptotic linear function $\text{ reg } I(G)^q$, for $q \geq 1,$ in terms of combinatorial data of the given graph $G.$Comment: 31 pages, 15 figure

Mouse Estrous Cycle Identification Tool and Images

The efficiency of producing timed pregnant or pseudopregnant mice can be increased by identifying those in proestrus or estrus. Visual observation of the vagina is the quickest method, requires no special equipment, and is best used when only proestrus or estrus stages need to be identified. Strain to strain differences, especially in coat color can make it difficult to determine the stage of the estrous cycle accurately by visual observation. Presented here are a series of images of the vaginal opening at each stage of the estrous cycle for 3 mouse strains of different coat colors: black (C57BL/6J), agouti (CByB6F1/J) and albino (BALB/cByJ). When all 4 stages (proestrus, estrus, metestrus, and diestrus) need to be identified, vaginal cytology is regarded as the most accurate method. An identification tool is presented to aid the user in determining the stage of estrous when using vaginal cytology. These images and descriptions are an excellent resource for learning how to determine the stage of the estrous cycle by visual observation or vaginal cytology

Description and evaluation of an EBM curriculum using a block rotation

BACKGROUND: While previous authors have emphasized the importance of integrating and reinforcing evidence-based medicine (EBM) skills in residency, there are few published examples of such curricula. We designed an EBM curriculum to train family practice interns in essential EBM skills for information mastery using clinical questions generated by the family practice inpatient service. We sought to evaluate the impact of this curriculum on interns, residents, and faculty. METHODS: Interns (n = 13) were asked to self-assess their level of confidence in basic EBM skills before and after their 2-week EBM rotation. Residents (n = 21) and faculty (n = 12) were asked to assess how often the answers provided by the EBM intern to the inpatient service changed medical care. In addition, residents were asked to report how often they used their EBM skills and how often EBM concepts and tools were used in teaching by senior residents and faculty. Faculty were asked if the EBM curriculum had increased their use of EBM in practice and in teaching. RESULTS: Interns significantly increased their confidence over the course of the rotation. Residents and faculty felt that the answers provided by the EBM intern provided useful information and led to changes in patient care. Faculty reported incorporating EBM into their teaching (92%) and practice (75%). Residents reported applying the EBM skills they learned to patient care (86%) and that these skills were reinforced in the teaching they received outside of the rotation (81%). All residents and 11 of 12 faculty felt that the EBM curriculum had improved patient care. CONCLUSIONS: To our knowledge, this is the first published EBM curriculum using an individual block rotation format. As such, it may provide an alternative model for teaching and incorporating EBM into a residency program

Theoretical study of the insulating oxides and nitrides: SiO2, GeO2, Al2O3, Si3N4, and Ge3N4

An extensive theoretical study is performed for wide bandgap crystalline oxides and nitrides, namely, SiO_{2}, GeO_{2}, Al_{2}O_{3}, Si_{3}N_{4}, and Ge_{3}N_{4}. Their important polymorphs are considered which are for SiO_{2}: $\alpha$-quartz, $\alpha$- and $\beta$-cristobalite and stishovite, for GeO_{2}: $\alpha$-quartz, and rutile, for Al_{2}O_{3}: $\alpha$-phase, for Si_{3}N_{4} and Ge_{3}N_{4}: $\alpha$- and $\beta$-phases. This work constitutes a comprehensive account of both electronic structure and the elastic properties of these important insulating oxides and nitrides obtained with high accuracy based on density functional theory within the local density approximation. Two different norm-conserving \textit{ab initio} pseudopotentials have been tested which agree in all respects with the only exception arising for the elastic properties of rutile GeO_{2}. The agreement with experimental values, when available, are seen to be highly satisfactory. The uniformity and the well convergence of this approach enables an unbiased assessment of important physical parameters within each material and among different insulating oxide and nitrides. The computed static electric susceptibilities are observed to display a strong correlation with their mass densities. There is a marked discrepancy between the considered oxides and nitrides with the latter having sudden increase of density of states away from the respective band edges. This is expected to give rise to excessive carrier scattering which can practically preclude bulk impact ionization process in Si_{3}N_{4} and Ge_{3}N_{4}.Comment: Published version, 10 pages, 8 figure

Validated outcome of treatment changes according to International League Against Epilepsy criteria in adults with drug-resistant focal epilepsy.

OBJECTIVE: Although many studies have attempted to describe treatment outcomes in patients with drug-resistant epilepsy, results are often limited by the adoption of nonhomogeneous criteria and different definitions of seizure freedom. We sought to evaluate treatment outcomes with a newly administered antiepileptic drug (AED) in a large population of adults with drug-resistant focal epilepsy according to the International League Against Epilepsy (ILAE) outcome criteria. METHODS: This is a multicenter, observational, prospective study of 1053 patients with focal epilepsy diagnosed as drug-resistant by the investigators. Patients were assessed at baseline and 6, 12, and 18 months, for up to a maximum of 34 months after introducing another AED into their treatment regimen. Drug resistance status and treatment outcomes were rated according to ILAE criteria by the investigators and by at least two independent members of an external expert panel (EP). RESULTS: A seizure-free outcome after a newly administered AED according to ILAE criteria ranged from 11.8% after two failed drugs to 2.6% for more than six failures. Significantly fewer patients were rated by the EP as having a "treatment failure" as compared to the judgment of the investigator (46.7% vs 62.9%, P < 0.001), because many more patients were rated as "undetermined outcome" (45.6% vs 27.7%, P < 0.001); 19.3% of the recruited patients were not considered drug-resistant by the EP. SIGNIFICANCE: This study validates the use of ILAE treatment outcome criteria in a real-life setting, providing validated estimates of seizure freedom in patients with drug-resistant focal epilepsy in relation to the number of previously failed AEDs. Fewer than one in 10 patients achieved seizure freedom on a newly introduced AED over the study period. Pseudo drug resistance could be identified in one of five cases