A Method of Circular Scleral Buckle Length Calculation in Retinal Detachment Surgery

Purpose. To develop a method of circular buckle length calculation for optimization of circular scleral buckling in retinal detachment surgery.Methods. At the first stage of the study a formula for calculation of optimal circular scleral buckle length for patients with various axial length (AL) of the eyeball was developed (90 eyes). These healthy eyes were divided into three groups, 30 eyes in each: group 1 — AL 19 to 23.5 mm, group 2 — AL 23.6 to 27 mm, group 3 — AL over 27 mm. In all the groups AL and equatorial diameter of the eyeball were measured with ultrasound A- and B- scanning (Тomey UD8000, Tomey AL 3000). Mathematic estimation of equatorial eyeball diameter dependence on AL was performed using correlation and regression analysis and the formula for optimal circular buckle length calculation was derived. At the second stage the derived formula was used in clinic during retinal detachment surgery in 15 eyes of 15 patients aged 28 to 44 years (37.6 ± 2.6) with subtotal retinal detachment occupying 2 to 3 quadrants. Follow-up period was 1 to 4 months (2.3 ± 0.5). For control, in all patient’s intraoperative measurement of the eyeball circumference in equatorial zone was performed.Results. The first step of the study revealed high correlation coefficient (r) between AL and equatorial eyeball diameter in groups 1 and 2, 0.89 and 0.87, respectively. In group 3 correlation coefficient was 0.57 which shows moderate correlation between AL and equatorial eyeball diameter. Group 3 (AL > 27 mm) was not included in deriving the formula for circular buckle length calculation. Finally, regression equation was obtained and the following formula for circular buckle length calculation was derived: L = 0.9π (8.05 + 0.66 AL), where L — circular buckle length, π = 3.14, AL — axial length of the eyeball. At the second stage of the study (eyes with AL less than 27 mm) anatomical attachment of the retina was achieved in all 15 cases (100 %), elevation of the buckle was 1.44 to 1.6 mm (1.5 ± 0.02), circular buckle shortening made 10 % of the initial eyeball diameter. Control measurement of eyeball diameter in equatorial zone coincided with calculated values, that is, equaled the data obtained from presented formula and from preoperative ultrasound measurement of equatorial eyeball diameter.Conclusions. The derived formula for circular buckle length calculation is highly effective for eyes with AL less than 27 mm: provides optimal height of impression roll (approximately 1.5 mm), reduces the risk of postoperative complications, it is simple in use and shortens the operation time. For calculation of circular buckle length for eyes with AL over 27 mm it is reasonable to use the data of preoperative ultrasound A-scan measurement of equatorial diameter of the eyeball.

Environment/Geography and Prosperity/Transparency (E), (4), (7)

This chapter discusses the influence of the environment and geography on prosperity and corruption and reviews some leading empirical works.A direct and robust empirical relationship exists between the environment/geography and the prosperity of nations. For instance, countries located in the inter-tropical or equatorial zone tend to be poorer than those located in temperate zones. Seasonal dynamics lead ecosystems and societies to accumulate and manage more resources, while equatorial species and people tend to consume the available resources immediately rather than storing, accumulating, and reinvesting the excess capital.An abundance of natural resources (i.e. fuels and minerals) tends to generate conditions for rent-seeking and corruption. Venezuela, Nigeria, or Arab countries are examples of countries located on the equator characterised by an abundance of natural resources and by high levels of corruption.

Statistical Analysis and Interpretation of High-, Mid- and Low-Latitude Responses in Regional Electron Content to Geomagnetic Storms

Geomagnetic storm is one of the most powerful factors affecting the state of the Earth’s ionosphere. Revealing the significance of formation mechanisms for ionospheric storms is still an unresolved problem. The purpose of the study is to obtain a statistical pattern of the response in regional electron content to geomagnetic storms on a global scale to interpret the results using the upper atmosphere model (the Global Self-consistent Model of the Thermosphere, Ionosphere, and Protonosphere), to make the detailed comparison with the thermospheric storm concept, and to compare the obtained pattern with results from previous statistical studies. The regional electron content is calculated based on the global ionospheric maps data, which allows us to cover the midlatitude and high-latitude zones of both hemispheres, as well as the equatorial zone. Most of the obtained statistical pattern agrees with the thermospheric storm concept and with the previous statistical studies: ionospheric responses at ionospheric storm main phases including their seasonal dependences for the high- and midlatitudes and some features of ionospheric responses at recovery phases. However, some of the statistical patterns are inconsistent with the thermospheric storm concept or contradicts the previous statistical studies: negative midlatitude ionospheric responses at recovery phases in the local winter, the domination of the spring response in the equatorial zone, seasonal features of the positive after-effects, the interhemispheric asymmetry of ionospheric responses, and the prestorm enhancement. We obtained that the contribution of electric field to the interpretation of the zonal and diurnal averaged storm-time regional electron content (REC) disturbances is insignificant. The positive after-storm effects at different latitudes are caused by n(O) disturbances.

A depletion of ammonia and water by storms in the deep atmosphere of Jupiter

<p>Microwave observations by the Juno spacecraft have shown that, contrary to expectations, the concentration of ammonia is still variable down to pressures of tens of bars in Jupiter. While mid-latitudes show a strong depletion, the equatorial zone of Jupiter has an abundance of ammonia that is high and nearly uniform with depth. In parallel, Juno determined that the Equatorial Zone is peculiar for its absence of lightning, which is otherwise prevalent most everywhere else on the planet. We show that a model accounting for the presence of small-scale convection and water storms originating in Jupiter’s deep atmosphere accounts for the observations. At mid-latitudes, where thunderstorms powered by water condensation are present, ice particles may be lofted high in the atmosphere, in particular into a region located at pressures between 1.1 and 1.5 bar and temperatures between 173K and 188K, where ammonia vapor can dissolve into water ice to form a low-temperature liquid phase containing about 1/3 ammonia and 2/3 water. We estimate that, following the process creating hailstorms on Earth, this liquid phase enhances the growth of hail-like particles that we call ‘mushballs’. Their growth and fall over many scale heights can effectively deplete ammonia, and consequently, water to great depths in Jupiter’s atmosphere. In the Equatorial Zone, the absence of thunderstorms shows that this process is not occurring, implying that small-scale convection can maintain a near homogeneity of this region. We predict that water, which sinks along with ammonia, should also be depleted down to pressures of tens of bars. Except during storms, Jupiter's deep atmosphere should be stabilized by the mean molecular weight gradient created by the increase in abundance of ammonia and water with depth.  This new vision of the mechanisms at play, which are both deep and latitude-dependent, has consequences for our understanding of Jupiter’s deep interior and of giant-planet atmospheres in general.</p>

Atmospheric reaction to the manifestations of the geodynamic activity of the Sulawes phenomenon according to satellite data

Using ATOVS satellite data (NOAA / POES) atmospheric disturbances that arose in the equatorial zone of Indonesia in the fall of 2018 were studied as a reaction to the geophysical manifestations of the geodynamic activity of a strong earthquake with a magnitude of M = 7,5. An archive of satellite information has been formed. A technique has been developed for analyzing the temperature of profiles during strong seismic activity of the Sulawes phenomenon. The atmospheric effects over the seismically active region of this earthquake were studied. It was found that in the troposphere during the study period anomalies with lower temperatures are observed above the epicenter region of the Indonesian earthquake and thermal anomalies with elevated temperatures are formed in the lower stratosphere.