Unsteady Magnetopause Reconnection Under Quasi-Steady Solar Wind Driving.

The intrinsic temporal nature of magnetic reconnection at the magnetopause has been an active area of research. Both temporally steady and intermittent reconnection have been reported. We examine the steadiness of reconnection using space-ground conjunctions under quasi-steady solar wind driving. The spacecraft suggests that reconnection is first inactive, and then activates. The radar further suggests that after activation, reconnection proceeds continuously but unsteadily. The reconnection electric field shows variations at frequencies below 10 mHz with peaks at 3 and 5 mHz. The variation amplitudes are ∼10-30 mV/m in the ionosphere, and 0.3-0.8 mV/m at the equatorial magnetopause. Such amplitudes represent 30%-60% of the peak reconnection electric field. The unsteadiness of reconnection can be plausibly explained by the fluctuating magnetic field in the turbulent magnetosheath. A comparison with a previous global hybrid simulation suggests that it is the foreshock waves that drive the magnetosheath fluctuations, and hence modulate the reconnection.

Phylogenetic Curved Optimal Regression for Adaptive Trait Evolution.

Regression analysis using line equations has been broadly applied in studying the evolutionary relationship between the response trait and its covariates. However, the characteristics among closely related species in nature present abundant diversities where the nonlinear relationship between traits have been frequently observed. By treating the evolution of quantitative traits along a phylogenetic tree as a set of continuous stochastic variables, statistical models for describing the dynamics of the optimum of the response trait and its covariates are built herein. Analytical representations for the response trait variables, as well as their optima among a group of related species, are derived. Due to the models' lack of tractable likelihood, a procedure that implements the Approximate Bayesian Computation (ABC) technique is applied for statistical inference. Simulation results show that the new models perform well where the posterior means of the parameters are close to the true parameters. Empirical analysis supports the new models when analyzing the trait relationship among kangaroo species.

A Case Study of Connection Between Ground Magnetic Field Perturbations and Tail Current Sheet Bursty Flows at X = -60 RE.

We report the first observations that connect a burst of fast flows and Pi2 fluctuations in the midtail current sheet at X ~-60 RE with ground magnetic negative bays and Pi2 pulsations at high latitudes near 70°. Both the flow burst and negative bays occurred around midnight and were isolated and lasted for ~10 min. The flow burst had the characteristics of a low-density plasma bubble. It was moving earthward at ~340 km/s and was accompanied by field-aligned currents. The timing and equatorward motion of magnetic bays can be accounted for by this earthward moving bubble. Enhanced Pi2 fluctuations were observed within both the bubble and the magnetic bays. Pressure anisotropy with higher parallel pressure was observed associated with the flow burst and was firehose unstable. We discuss firehose instability as one of the possible mechanisms for the Pi2 fluctuations.

Deep vein thrombosis due to continuous prone positioning after retinal detachment surgery.

In March 2014, a 56-year-old woman without previous underlying disease underwent encircling scleral buckling, 20-gauge pars plana vitrectomy, cryotherapy around a retinal tear, and gas-fluid exchange with 15% perfluoropropane flush for upper rhegmatogenous retinal detachment of the left eye. However, she developed progressive left leg swelling, pain, warmth, and redness, associated with difficulty in elevating her left leg after continuously maintaining a prone head position when either lying down or sitting for 2 days. When she arrived at the emergency room, she had an elevated D-dimer level. After undergoing Doppler ultrasound imaging, she was diagnosed as having deep vein thrombosis of the left leg. She received anticoagulation therapy with enoxaparin and warfarin overlapping for 7 days. The edema, pain, and paresthesia of her left leg were relieved. However, because of the risk of bleeding with anti-coagulation drug usage, the patient needed to be monitored for 6 months. Prone positioning for gas tamponade is important for anatomic and functional success in retinal detachment surgery; however, timely walking and rest between periods of continuous prone positioning should be encouraged to prevent deep vein thrombosis and other impaired circulation-related complications.

Rapid regression of cystoid macular edema associated with cytomegalovirus retinitis in adult acute myeloid leukemia by intravitreal methotrexate combined with oral valganciclovir: A case report with comparison of binocular outcome.

Cytomegalovirus (CMV) retinitis is a late complication of organ and hematopoietic stem cell transplant, the risk of which depends on the degree of immunosuppression. With the institution of preemptive ganciclovir therapy early after transplant, most patients survive episodes of life-threatening CMV infection during the early months (usually the first 3 months) after transplant and hence late onset of CMV disease, such as CMV retinitis, is being recognized more frequently. Direct involvement of the macula or optic head remains the leading cause of visual loss in patients with CMV retinitis, but there are few studies investigating the management of this condition. Herein, we present the case of 28-year-old man who had acute myeloid leukemia and developed CMV retinitis with bilateral cystoid macular edema and optic swelling in the right eye 6 months after bone marrow transplant. He received treatment with intravitreal methotrexate in the right eye in combination with oral valganciclovir. Visual acuity improved 1 month after four weekly injections of intravitreal methotrexate 400 µg/0.1 mL. Resolved disc swelling and regression of macular edema were also observed. By comparing binocular outcome, we present our findings and discuss the possible efficacy and safety of this treatment with respect to regression of anatomical damage and improvement in visual acuity.

Axial length and subfoveal choroidal thickness in individuals with age-related macular degeneration.

PURPOSE: To compare axial length (AL) and subfoveal choroidal thickness (SFCT) between individuals with age-related macular degeneration (AMD) and controls with no lesions. METHODS: This was a case-control study. In total, 853 eyes of 484 patients (>65 years), including 397 eyes at various AMD stages and 456 eyes with no fundus lesions (controls) were recruited. Using color fundus photography, eyes were grouped according to AMD degree. AL was automatically measured using IOL Master and SFCT was manually measured by two independent observers. The associations among age, AL, SFCT, and each AMD grade were analyzed. RESULTS: Out of 853 eyes, 456 had no lesions, 217 contained drusen only, 134 had early AMD, and 46 had late AMD. The eyes with late AMD were older (p = 0.007) and had longer AL (p ≥ 0.001) and thinner SFCT (p < 0.001) compared with groups of no fundus lesions, drusen only, and early AMD. SFCT in eyes with late AMD decreased by 19.20 µm (p = 0.049), 24.78 µm (p = 0.029), and 15.56 µm (p = 0.162) compared with groups of no fundus lesions, drusen only, and early AMD, respectively. SFCT decreased by 14.18 µm/mm increase in AL (p < 0.001). The odds ratio (OR) for late AMD by longer AL (≥25 mm) and thinner SFCT (<240 µm) was 4.54 (χ2 = 9.36; p = 0.002) and 4.86 (χ2 = 17.62; p < 0.001), respectively, and was 9.57 (χ2 = 18.07; p < 0.001) when both AL ≥ 25 ≥m and SFCT < 240 µm. CONCLUSION: Eyes with late AMD have distinct reduced SFCT and elongated AL. Eyes with thinner SFCT and longer AL showed high ORs for late AMD and even higher ORs when both factors were simultaneously present. These findings illustrate the crucial pathophysiological role of these two important ocular fac tors and arouse our attention to patients with both characteristics, especially in Asian countries where the prevalence of myopia are disturbingly high.