Lens nuclear opacity quantitation with long-range swept-source optical coherence tomography: correlation to LOCS III and a Scheimpflug imaging-based grading system

PurposeTo quantitate lens nuclear opacity using long-range swept-source optical coherence tomography (SS-OCT) images and to evaluate the correlation of this method to Lens Opacities Classification System III (LOCS III) and a Scheimpflug imaging-based grading system (Pentacam Nuclear Stage function; PNS).MethodsThis study enrolled 120 participants (120 eyes) with age-related nuclear cataracts. The best-corrected visual acuity (BCVA), LOCS III nuclear opalescence (NO) and nuclear colour (NC) were obtained. The nuclear density measured using PNS function (NDPNS) was recorded. Three successive series of long-range SS-OCT images were captured, and the nuclear region was analysed using ImageJ (NIH, Bethesda, Maryland, USA) to generate SS-OCT image-based nuclear density (NDSS-OCT). The repeatability of NDSS-OCT measurement was evaluated using within-subject coefficient of variation (CVw) and intraclass correlation coefficient (ICC). Correlations of NDSS-OCT with NO and NC, BCVA and NDPNS were analysed. According to the integrity of nucleus imaged by Pentacam, patients were divided into two groups, and the parameters were compared between groups.ResultsThe CVw and ICC for NDSS-OCT measurement were 1.5 % and 0.994, respectively. The NDSS-OCT significantly correlated with NO (r=0.831), NC (r=0.873), BCVA (r=0.655) and NDPNS (r=0.891). The NDSS-OCT, NO and NC, and BCVA were significantly different between the two groups.ConclusionLens nuclear opacity quantitation using long-range SS-OCT images was repeatable and correlated well with LOCS III and PNS function. The Scheimpflug principle had a limitation in imaging dense nucleus. Long-range SS-OCT seems more promising for objectively and quantitatively assessing lens nuclear opacity.

Obama's push on nuclear arms control faces hurdles

Subject The US arms control agenda. Significance Despite having less than a year in office, President Barack Obama's administration is sustaining a high-profile arms control agenda in 2016. The administration wants to restore several damaged treaties with Russia, broaden Russia-China-US cooperation on various non-proliferation issues and leave Obama's successor a firm nuclear security architecture. Arms control is a consultative, long-term diplomatic process, and is susceptible to the political imperatives of more immediate regional crises. Impacts Tacit US support of Israeli nuclear opacity will undermine arms control efforts in the Middle East. Post-Obama arms control efforts are likely to focus on the security of nuclear material, rather than strategic arms reductions. Senate retirements will undermine US arms control advocacy in Congress. The United States will retain its nuclear arsenal indefinitely despite criticism from its allies.

Multi-frequency, multi-epoch VLBI observations of the M87 jet

We present some of preliminary results obtained by our dense monitoring project of the M87 jet with VERA 22 and 43 GHz starting from October 2010. The aims of this monitor are to clarify the detailed physical properties of the M87 jet base near the black hole, including the connection to γ-ray productions, jet kinematics and nuclear opacity. We detected a remarkable increase of the radio flux from the jet base of M87 during an elevated very-high-energy γ-ray activity occurred in the early 2012, suggesting that the γ-ray is produced in the immediate vicinity of the central black hole.

The Last Taboo: Israel's Bomb Revisited

Is it really possible to redesign and buttress the nonproliferation regime, as the Iranian case requires, while leaving Israel's nuclear capacity an untouched taboo? Is it healthy for Israeli democracy or global security to continue with the path of nuclear opacity?