Freezing of viable embryos and larvae of marine shrimp, Penaeus semisulcatus de Haan

Although sperm cryopreservation has been carried out successfully in a number of commercially important aquatic species, particularly in some teleost fish (see review of Rana in Muir & Roberts 1993) and also shellfish (Subramoniam 1993), the technology is still not at the stage of advanced commercial application that is seen in domestic mammals. Cryopreservation of eggs and embryos, of aquatic animals however, is a virgin field in cryobiology and has not yet received any appreciable amount of attention. The first successful attempt at the cryopreservation of embryos of sea urchin was reported by Asahina & Takahashi (1978). Later Zell (1978) and Erdahl & Graham (1980) have reported preliminary attempts to freeze the eggs of rainbow trout

Stormwater sand filters in water-sensitive urban design

This paper investigates the suitability of sand filters for harvesting and treating stormwater for non-potable reuse purposes. A stormwater sand filtration device was constructed in a small urban catchment in Sydney, Australia. A sand filter is typically used in water-sensitive urban design (WSUD) as a component of a treatment train to remove pollution from stormwater before discharge to receiving waters, to groundwater or for collection and reuse. This paper describes an 18 month field study undertaken to determine the effectiveness and pollutant removal efficiency of a sand filter, and the differences in the pollutant removal efficiency of two grades of sand. A comparison of pollutant removal with previous literature on sand filters showed similar efficiencies but nutrient removal was higher than expected. A further unexpected result was that the coarse filter media performed as well as the fine media for most pollutant types and was superior in suspended solids removal. Improved modelling equations for predicting suspended solids and total phosphorus removal in sand filters are also presented in this paper

In vitro propagation of Alternanthera sessilis (sessile joyweed), a famine food plant

A complete protocol for micropropagation of Alternanthera sessilis using leaf explants was developed. Leaf explants from A. sessilis established on Murashige and Skoog medium were treated with various concentrations and combinations of auxins and cytokinins to determine the best method for callus formation, shoot regeneration and root formation. MS medium supplemented with 1 mg/l BAP and 1 mg/l 2,4-D was determined to be the most suitable for callus induction. After 2 weeks, the callus wasthen transferred to shooting media which consisted of half strength MS basal medium, 1 mg/l IAA and 1 mg/ l BAP. After 4 weeks, structures were observed with their basal ends embedded on the callus. These structures turned into green colored shoot buds. MS medium supplemented with 1 mg/l IAA and 1 mg/l BAP showed maximum shoot multiplication. For rooting, the optimal medium was half strength MS medium supplemented with 1 mg/l IBA. Rooted plantlets were then transferred to sunbag vessels which provided the high humidity environment. The hardened plants were then successfullyestablished in the soil medium and can function in the natural environment

Chemical-assisted physico-biological water mining system

Water mining is the process of extracting valuable water from a sewerage network by treating raw sewage to high standards. A range of commercially viable water mining treatment technologies are now available to treat sewage to specified water quality targets. Most of these technologies have minimal plant footprint requirements, making them suitable for decentralised operations. This paper discusses a hybrid water mining system that includes chemically assisted fine solids separation followed by a biological treatment process. Results from the first proof testing of this water mining system in Sydney, Australia are presented. The results confirm the suitability of the hybrid system for producing high-quality water for non-potable reuse

Prospects of Grouper Culture in India

The "Groupers" of the genus Epinephelus are excellent marine food fishes in the Indo Pacific and Carribean regions and have assumed importance for commercial culture in recent year

Formation of lead lanthanum zirconate titanate films by heat treatments

Lead lanthanum zirconate titanate (PLZT) also called lanthanum doped PZT films were deposited by RF magnetron sputtering. PLZT in the perovskite phase is required to obtain a film with a large electro-optic effect. It can also be used as a ferroelectric and piezoelectric material. However films that have not been heat treated either during or after deposition are typically in the pyrochlore phase. Perovskite PLZT films obtained by heating the substrate during sputtering showed little evidence of cracks in the films sputtered without heating the substrate were not in the Perovskite phase and post deposition annealing was required to do so. Both furnace and rapid thermal annealing were investigated but in both cases cracks formed in the films to various degrees. Such films are unsuitable for optical device fabrication. To determine the orientation of PLZT films X-ray diffraction (XRD) spectras were obtained and compared. Samples were prepared on silicon substrates which had a thin film of 20 nm Ti/100 nm Pt deposited by electron beam evaporation. Sputtering was done in an argon atmosphere using a PLZT (9/65/35) target. Thicknesses of 1 mum were obtained. Some samples were heated during sputtering up to a temperature of 650 degC. Annealing temperatures were varied from 500 to 750 degC. The best results (determined by XRD) were obtained for RTA at 750 degC for 10 minutes in air. XRD spectra of before and after annealing show a significant increase in the Perovskite peaks. The patterning of these films to form optical waveguides by ion beam etching is also presented. The samples were patterned with photoresist masks and ion beam etched using argon at a gun voltage of 500

Implementation of Fault-tolerant Quantum Logic Gates via Optimal Control

The implementation of fault-tolerant quantum gates on encoded logic qubits is considered. It is shown that transversal implementation of logic gates based on simple geometric control ideas is problematic for realistic physical systems suffering from imperfections such as qubit inhomogeneity or uncontrollable interactions between qubits. However, this problem can be overcome by formulating the task as an optimal control problem and designing efficient algorithms to solve it. In particular, we can find solutions that implement all of the elementary logic gates in a fixed amount of time with limited control resources for the five-qubit stabilizer code. Most importantly, logic gates that are extremely difficult to implement using conventional techniques even for ideal systems, such as the T-gate for the five-qubit stabilizer code, do not appear to pose a problem for optimal control.Comment: 18 pages, ioptex, many figure

On the large sunfish landed near Mandapam

A sunfish, Ranzania laevis (Pennant) measuring 660 mm total length was caught on 5.3.1998 in shoreseine near Mandapam in Palk Bay. In fresh condition its colour was bluish with dark above and pale white below with small hexagonal plates and smooth skin. Six streaks of lighter colour bordered with dark descended from snout to gill slits and curved downwards to the ventral profile. The posterior three streaks were branched with dark spots. The lips were produced forward beyond the teeth closing as a vertical slit

The plasma nitric oxide and homocysteine levels and their association with insulin resistance in South Indian women with polycystic ovary syndrome

Background: Women with polycystic ovary syndrome (PCOS) exhibit features of the metabolic syndrome apart from low-grade chronic inflammation and endothelial dysfunction and may be at increased risk for cardiovascular disease (CVD). The Nitric oxide (NO) and Homocysteine (Hcy) are important plasma markers of endothelial dysfunction, an early marker of atherosclerosis. There are no Indian studies on NO and Hcy levels in women with PCOS and their association with Insulin Resistance (IR). Therefore the present study is to estimate plasma levels of NO and Hcy in south Indian women with PCOS and association with insulin resistance.Methods: 104 women with PCOS and 95 healthy age matched control subject were enrolled in the study. Standard physical methods and Chemiluminescent Immunoassay technique were employed for estimation of Anthropometric parameter and plasma sex hormones respectively. Fasting insulin, glucose, NO and Hcy were measured by standard methods. Insulin resistance was evaluated by using Homeostasis Model Assessment for Insulin Resistance (HOMA- IR)Results: Women with PCOS had significantly higher insulin resistance (P<0.01), Hcy (p<0.05) and lower NO levels (P<0.05), IR was positively correlated with Hcy (r= 0.610, p<0.01) and negatively correlated with NO (r= -0.285; p<0.01)Conclusions: Our data revealed that South Indian women with PCOS had elevated IR and homocyeteine and lowered NO levels