An AFM Approach Applied in a Study of α-Crystallin Membrane Association: New Insights into Lens Hardening and Presbyopia Development

The lens of the eye loses elasticity with age, while α-crystallin association with the lens membrane increases with age. It is unclear whether there is any correlation between α-crystallin association with the lens membrane and loss in lens elasticity. This research investigated α-crystallin membrane association using atomic force microscopy (AFM) for the first time to study topographical images and mechanical properties (breakthrough force and membrane area compressibility modulus (KA), as measures of elasticity) of the membrane. α-Crystallin extracted from the bovine lens cortex was incubated with a supported lipid membrane (SLM) prepared on a flat mica surface. The AFM images showed the time-dependent interaction of α-crystallin with the SLM. Force spectroscopy revealed the presence of breakthrough events in the force curves obtained in the membrane regions where no α-crystallin was associated, which suggests that the membrane’s elasticity was maintained. The force curves in the α-crystallin submerged region and the close vicinity of the α-crystallin associated region in the membrane showed no breakthrough event within the defined peak force threshold, indicating loss of membrane elasticity. Our results showed that the association of α-crystallin with the membrane deteriorates membrane elasticity, providing new insights into understanding the molecular basis of lens hardening and presbyopia

Hydrological conditions in seagrass beds in Palk Bay and Gulf of Mannar, southeast coast of India

Comparative analysis has been made on the water quality parameters in three seagrass sites, Sangumal and Farm pond in Palk Bay; Thonithurai and one non seagrass site - Kundhukaal point in the Gulf of Mannar from January 2006 to December 2007. The atmospheric temperature ranged from 24.8° to 35.3 °C, sea surface temperature from 25° to 35°C, pH from 7.44 to 8.44, dissolved oxygen from 1.0 ml to 5.9 ml l-1 and total suspended solids from 10.7 mg to 122 mg l-1 in the four sites. The maximum concentration of phosphate, silicate, nitrite and nitrate in the water were 1.22 μmol, 5.83 μmol, 0.63 μmol and 2.03 μmol l-1 respectively. Sangumal had the maximum input of nutrients especially during the northeast monsoon. Pearsons correlation coefficient showed significant positive correlation (ρ<0.01) of sea surface temperature with pH, salinity, dissolved oxygen and negative correlation with total suspended solids, nitrite and ammonia. Though ANOVA did not show significant difference in water quality parameter between sites with and without seagrass, highly significant difference (ρ<0.001) was observed seasonally in sea surface temperature, salinity, nitrite, ammonia, wind velocity, rainfall and number of rainy days, thereby influencing the growth of seagrass beds

Preparation and Characterization of Nanostructured CaCu2.90 Zn0.10 Ti4O12 Ceramic

Nanostructure CaCu2.90Zn0.10Ti4O12 (CCZTO) electronic ceramic was synthesized by semi‐wet route. The objective of this route is to enable the calcination and sintering processes to go for completion in shorter time and at lower temperature.The samples were characterized by XRD, TEM, SEM and EDX analyses. The crystallite size of the CCZTO ceramic, obtained by XRD using Debye Scherrer formula, range from 38‐74nm which is in good agreement with the particle size observed by TEM analysis. It was observed clearly that the grain size significantly increased with an increase in sintering duration. Dielectric measurements were carried out by LCR meter in the temperature range, 300‐  500K, at few selected frequencies. It was also observed that the dielectric constant and dielectric loss of CCZTO are temperature independent in higher frequency whereas temperature dependent in low frequency region. The ceramics exhibit high dielectric constant of 1.35 x 10 4 at 1 kHz

Yield and Quality of Passion Fruit in Relation to Training Systems

Four different training systems, viz., Kniffin, High trellis, Tatura and Bower were evaluated in passion fruit cv. Kaveri. Kniffin system with 4 arms recorded highest cumulative yield of 67.22 t/ha with a cost:benefit ratio of 1:4.25, followed by Kniffin 2 arm and 6 arm, respectively. Kniffin system was also the most ideal system of training for passion fruit, facilitating easy cultural operations. Although Tatura system recorded highest cumulative yield/vine (43.57kg), it registered lowest yield/ha, largely due to lower plant population/ha (1250 vines/ha). Fruit quality parameters like TSS, Vit. C, carotene content and titrable acidity were not significantly influenced by different training systems. Similarly, interception of Photosynthetically Active Radiation (PAR) by the canopy did not differ significantly among training systems. Though photosynthetic rate did not differ significantly, shaded leaves in the canopy did not contribute photosynthates and were parasitic on the vine

Environmental monitoring in Sea cage culture

Cage culture is a fast growing industry all over the world and demands good environmental practices to assure sustainability. The sustained development of coastal aquaculture has reached a good understanding with the environment, respecting it and undertaking actions that tend to diminish the possible impacts that may arise from this activity. In order to do so, measures are to be taken in production to avoid degrading the environment, whilst still being appropriate, economically viable and socially acceptable. In this sense, it has been considered necessary to develop some basic environmental strategies to assure the best site for the aquaculture purposes, avoiding possible confrontations with other coastal uses