Distinguishing wet from dry age-related macular degeneration using three-dimensional computer-automated threshold Amsler grid testing

Background/aims: With the increased efficacy of current therapy for wet age-related macular degeneration (AMD), better ways to detect wet AMD are needed. This study was designed to test the ability of three-dimensional contrast threshold Amsler grid (3D-CTAG) testing to distinguish wet AMD from dry AMD. Methods: Conventional paper Amsler grid and 3D-CTAG tests were performed in 90 eyes: 63 with AMD (34 dry, 29 wet) and 27 controls. Qualitative comparisons were based upon the three-dimensional shapes of central visual field (VF) defects. Quantitative analyses considered the number and volume of the three-dimensional defects. Results: 25/34 (74%) dry AMD and 6/29 (21%) wet AMD eyes had no distortions on paper Amsler grid. Of these, 5/25 (20%) dry and 6/6 (100%) wet (p=0.03) AMD eyes exhibited central VF defects with 3D-CTAG. Wet AMD displayed stepped defects in 16/28 (57%) eyes, compared with only 2/34 (6%) of dry AMD eyes (p=0.002). All three volumetric indices of VF defects were two- to four-fold greater in wet than dry AMD (p<0.006). 3D-CTAG had 83.9% positive and 90.6% negative predictive values for wet AMD. Conclusions: 3D-CTAG has a higher likelihood of detecting central VF defects than conventional Amsler grid, especially in wet AMD. Wet AMD can be distinguished from dry AMD by qualitative and quantitative 3D-CTAG criteria. Thus, 3D-CTAG may be useful in screening for wet AMD, quantitating disease severity, and providing a quantitative outcome measure of therapy

Effects of Soil Moisture on the Pupation Behavior of \u3ci\u3eAltica Subplicata\u3c/i\u3e (Coleoptera: Chrysomelidae)

The effects of soil moisture on the pupation behavior of a willow flea beetle, Attica subplicata, were studied with two laboratory experiments. To test the effect of soil moisture on the number of larvae pupating and pupal survival, we set up pupation chambers filled with sand with three different soil moistures: dry, moist, and wet. The number of larvae pupating was much greater in the moist sand and wet sand treatments than in the dry sand treatment. Pupal survival, as measured by the proportion of adults successfully emerging, was greater in the moist treatment than in the wet or dry treatments. Thus, overall pupation success (number of adults successfully emerging) was greater in the moist treatment than in the wet treatment and greater in the wet treatment than in the dry treatment. To examine the effect of soil moisture on choice of pupation site, we provided the larvae with a choice of two soil moistures in each pupation chamber. More larvae chose wet over dry conditions and more chose moist over dry conditions, but larvae did not discriminate between moist and wet conditions. The improved pupation in areas with higher soil moisture is consistent with the field distribution pattern of greater beetle densities on dunes with greater soil moisture

Napier grass performance under agroforestry systems of upland area on Tuntang watershed, Indonesia

The success of forage cultivation effort extremely depends on several factors, such as kinds of forage, climate, water, and soil fertility. A research on napier grass in agroforestry system conducted to find out soil fertility, growth, production, and quality of forage in agroforestry system in headwaters of Tuntang watershed. This research used factorial plan 2 x 2 which was repeated five times. The first factor was agroforestry system (AFS-1 and AFS-2) and the second factor was defoliation in wet and dry season. Parameter observed were height of plants, forage production, dry matter content, crude protein, and crude fibre. In addition, agroforestry soil samples comprised specific weight of soil, pH, and N total. Height of plant in AFS-1 was higher (85.1 cm) than AFS-2 system (71.5 cm). Season had an affect on plants growth which was shown by height of plant that was lower during dry season (66.8 cm) than during wet season (89.8 cm). AFS-1 system had a better forage yield than AFS-2. Dry matter of forage varied between agroforestry system and season. The lowest dry matter during wet season could be found in AFS-1. The highest protein content in AFS-1 could be found during wet season (11.27%), and the lowest protein content in AFS-2 was during dry season (6.0%). Crude fibre of napier grass in AFS-2 was higher than AFS-1. Crude fibre content during dry season was higher than during wet season. The napier grass in AFS-1 has a better growth, production, and quality than in AFS-2. The growth, forage yield, crude protein and fibre contents during wet season in the upland area of Tuntang watershed are better than during dry season. The best dry matter content is in AFS-2 during dry season and the highest crude protein content of napier grass lies in AFS-1 during wet season. Keywords : Agroforestry, napier grass, crude protein, crude fibe

The use of video imagery to analyse groundwater and shoreline dynamics on a dissipative beach

Groundwater seepage is known to influence beach erosion and accretion processes. However, field measurements of the variation of the groundwater seepage line (GWSL) and the vertical elevation difference between the GWSL and the shoreline are limited. We developed a methodology to extract the temporal variability of the shoreline and the wet-dry boundary using video imagery, with the overarching aim to examine elevation differences between the wet-dry boundary and the shoreline position in relation to rainfall and wave characteristics, during a tidal cycle. The wet-dry boundary was detected from 10-minute time-averaged images collected at Ngaranui Beach, Raglan, New Zealand. An algorithm discriminated between the dry and wet cells using a threshold related to the maximum of the red, green and blue intensities in Hue-Saturation-Value. Field measurements showed this corresponded to the location where the watertable was within 2 cm of the beachface surface. Timestacks, time series of pixels extracted from cross-shore transects in the video imagery, were used to determine the location of the shoreline by manually digitizing the maximum run-up and minimum run-down location for each swash cycle, and averaging the result. In our test data set of 14 days covering a range of wave and rainfall conditions, we found 6 days when the elevation difference between the wet-dry boundary and the shoreline remained approximately constant during the tidal cycle. For these days, the wet-dry boundary corresponded to the upper limit of the swash zone. On the other 8 days, the wet-dry boundary and the shoreline decoupled with falling tide, leading to elevation differences of up to 2.5 m at low tide. Elevation differences between the GWSL and the shoreline at low-tide were particularly large when the cumulative rainfall in the preceding month was greater than 200 mm. This research shows that the wet-dry boundary (such as often used in video shoreline-finding algorithms) is related to groundwater seepage on low-sloped, medium to fine sand beaches such as Ngaranui Beach (mean grain size~0.27 mm, beach slope ~1:70) and may not be a good indicator of the position of the shoreline

Triaxial compression tests on a crushable sand in dry and wet conditions

A calcareous sand from the Persian Gulf is subjected to a series of dry and fully drained saturated triaxial shear tests. The samples are prepared at relative densities of 65% and either left dry or saturated. They are consolidated to confining pressures ranging from 50 to 750 kPa, and sheared until shear strains of 20%. It is shown that the stress-strain and strength characteristics of crushable sand are significantly affected by the presence of water. During shearing of wet samples, there is less dilation, the peak is postponed and a lower shear strength is reached compared to dry samples. Crushability is assessed by comparing the granulometry before and after the triaxial tests. While both dry and wet samples show breakage, the wet sand is consistently more crushable. It is stated that the higher crushability of the wet sand suppresses its dilation during shearing

Mercury deposition in southern New Hampshire, 2006–2009

The atmospheric deposition of mercury (Hg) occurs via several mechanisms including wet, dry, and occult processes. In an effort to understand the atmospheric cycling and seasonal depositional characteristics of Hg, event-based wet deposition samples and reactive gaseous Hg (RGM) measurements were collected for approximately 3 years at Thompson Farm (TF), a near-coastal rural site in Durham, NH, part of the University of New Hampshire AIRMAP Observing Network. Total aqueous mercury exhibited seasonal patterns in Hg wet deposition at TF. The lowest Hg wet deposition was measured in the winter with an average total seasonal deposition of 1.56 μg m−2compared to the summer average of 4.71 μg m−2. Inter-annual differences in total wet deposition are generally linked with precipitation volume, with the greatest deposition occurring in the wettest year. Relationships between surface level RGM and Hg wet deposition were also investigated based on continuous RGM measurements at TF from November 2006 to September 2009. No correlations were observed between RGM mixing ratios and Hg wet deposition, however the ineffective scavenging of RGM during winter precipitation events was evidenced by the less frequent depletion of RGM below the detection level. Seasonal dry deposition of reactive gaseous Hg (RGM) was estimated using an order-of-magnitude approach. RGM mixing ratios and dry deposition estimates were greatest during the winter and spring. The seasonal ratios of Hg wet deposition to RGM dry deposition vary by up to a factor of 80

Energy dissipation in sheared wet granular assemblies

Energy dissipation in sheared dry and wet granulates is considered in the presence of an externally applied confining pressure. Discrete element simulations reveal that for sufficiently small confining pressures, the energy dissipation is dominated by the effects related to the presence of cohesive forces between the particles. The residual resistance against shear can be quantitatively explained by a combination of two effects arising in a wet granulate: (i) enhanced friction at particle contacts in the presence of attractive capillary forces and (ii) energy dissipation due to the rupture and reformation of liquid bridges. Coulomb friction at grain contacts gives rise to an energy dissipation which grows linearly with increasing confining pressure for both dry and wet granulates. Because of a lower Coulomb friction coefficient in the case of wet grains, as the confining pressure increases the energy dissipation for dry systems is faster than for wet ones

Impact of different particle size distributions on anaerobic digestion of the organic fraction of municipal solid waste

Particle size may significantly affect the speed and stability of anaerobic digestion, and matching the choice of particle size reduction equipment to digester type can thus determine the success or failure of the process. In the current research the organic fraction of municipal solid waste was processed using a combination of a shear shredder, rotary cutter and wet macerator to produce streams with different particle size distributions. The pre-processed waste was used in trials in semi-continuous ‘wet’ and ‘dry’ digesters at organic loading rate (OLR) up to 6 kg volatile solids (VS) m?3 day?1. The results indicated that while difference in the particle size distribution did not change the specific biogas yield, the digester performance was affected. In the ‘dry’ digesters the finer particle size led to acidification and ultimately to process failure at the highest OLR. In ‘wet’ digestion a fine particle size led to severe foaming and the process could not be operated above 5 kg VS m?3 day?1. Although the trial was not designed as a direct comparison between ‘wet’ and ‘dry’ digestion, the specific biogas yield of the ‘dry’ digesters was 90% of that produced by ‘wet’ digesters fed on the same waste at the same OLR.<br/

TAXONOMIC STRUCTURE OF THE PLANT COMMUNITIES OF TREE PLANTATIONS AT THE IRON ORE DUMPS IN KRYVYI RIH CITY

The development of woody-shrub vegetation in dump ecotopes for a long time was considered as the perspective of phytorecultivation problems. As a result of preliminary studies of the Department of Optimization of Technogenic Landscapes of the Kryvyi Rih Botanical Garden of National Academy of Sciences of Ukraine, it has been established that optimal conditions for its development are created in the dump ecotopes, firstly, at a certain level of moisture and mineral nutrition, which corresponds to a range of a number of hygrotopes: from dry to fresh (clays), from dry to wet (loams), from wet to very wet (sands), from raw to wet (gravel and screes) and wet (pebbles and gravel)