Prevalence of osteoporosis in Australian women : Geelong Osteoporosis Study

To evaluate the prevalence of osteoporosis at various sites among Australian women, cross-sectional bone mineral density (BMD) data for adult females was obtained from an age-stratified population-based sample (n = 1494; 20–94 yr) drawn at random from the Barwon Statistical Division, a population characteristic of Australia. Age- and weight- (and for three sites, height) matched reference ranges for BMD at the lumbar spine, proximal femur, forearm, and total body were developed using regression techniques. The cutoff BMD level for osteoporosis at the PA spine was 0.917 g/cm² and 0.713 g/cm² at the femoral neck according to the World Health Organization (WHO) guidelines. The upper cutoff level for osteopenia was 1.128 g/cm² at the PA spine and 0.913 g/cm² for the femoral neck. The proportion of Australian women categorized as having osteoporosis at the PA spine, femoral neck, or midforearm ranged from 0.9% among those aged 40–44 yr to 87.0% for those older than 79 yr. This study provides reference data representative of the Australian female population. A large proportion of elderly Australian women has osteoporosis according to the WHO guidelines.

Integral approach and numerical improvement to calculate carbon concentration profiles in carburising

The carbon diffusion in steel, where the carbon diffusivity varies with the carbon content, was solved with the integral methods under the third boundary condition. The variation of carbon diffusivity in steel with the carbon content was described with two different functions, linear dependence and exponential dependence. The integral approximation for both cases was improved with the numerical computation to more accurately predict the carbon profiles. The integral solution is more accurate than the formulation based on the assumption of a constant diffusivity or those based on the assumption of a constant diffusivity and/or constant carbon content at part surface. It is also more easily used in practice than the numerical method to describe the carburising process and predict the carbon content at steel surface and carbon profiles in treated layer.

Enzymatic synthesis of isopropyl myristate using immobilized lipase from Bacillus cereus MTCC 8372

A purified alkaline thermo-tolerant bacterial lipase from Bacillus cereus MTCC 8372 was immobilized on a Poly (MAc- co -DMA- cl -MBAm) hydrogel. The hydrogel showed approximately 94% binding capacity for lipase. The immobilized lipase (2.36 IU) was used to achieve esterification of myristic acid and isopropanol in n -heptane at 65 °C under continuous shaking. The myristic acid and isopropanol when used at a concentration of 100 mM each in n -heptane resulted in formation of isopropyl myristate (66.0 ± 0.3 mM) in 15 h. The reaction temperature below or higher than 65°C markedly reduced the formation of isopropyl myristate. Addition of a molecular sieve (3 Å × 1.5 mm) to the reaction mixture drastically reduced the ester formation. The hydrogel bound lipase when repetitively used to perform esterification under optimized conditions resulted in 38.0 ± 0.2 mM isopropyl myristate after the 3 ^rd cycle of esterification.

Purification and characterization of a low molecular mass alkaliphilic lipase of Bacillus cereus MTCC 8372

A low molecular mass alkaliphilic extra-cellular lipase of Bacillus cereus MTCC 8372 was purified 35-fold by hydrophobic interaction (Octyl-Sepharose) chromatography. The purified enzyme was found to be electrophoretically pure by denaturing gel electrophoresis and possessed a molecular mass of approximately 8 kDa. It is a homopentamer of 40 kDa as revealed by native-PAGE. The lipase was optimally active at 55 °C and retained approximately half of its original activity after 40 min incubation at 55 °C. The enzyme was maximally active at pH 8.5. Mg ²⁺ , Cu ²⁺ , Ca ²⁺ , Hg ²⁺ , Al ³⁺ and Fe ³⁺ at 1 mM enhanced hydrolytic activity of the lipase. Interestingly, Hg ²⁺ ions synergized and Zn ²⁺ and Co ²⁺ ions antagonized the lipase activity. Among surfactants, Tween 80 promoted the lipase activity. Phenyl methyl sulfonyl fluoride (PMSF, 15 mM) decreased 98% of original activity of lipase. The lipase was highly specific towards p -nitrophenyl palmitate and showed a V _max and K _m of 0.70 mmol.mg ⁻¹ .min ⁻¹ and 32 mM for hydrolysis of p NPP.

Synthesis of ethyl acetate employing celite-immobilized lipase of Bacillus cereus MTCC 8372

A wide range of fatty acid esters can be synthesized by esterification and transesterification reactions catalyzed by lipases in non-aqueous systems. In the present study, immobilization of a purified alkaline extra-cellular lipase of Bacillus cereus MTCC 8372 by adsorption on diatomaceous earth (celite) for synthesis of ethyl acetate via transesterification route was investigated. B. cereus lipase was deposited on celite (77% protein binding efficiency) by direct binding from aqueous solution. Immobilized lipase was used to synthesis of ethyl acetate from vinyl acetate and ethanol in n -nonane. Various reaction conditions, such as biocatalyst concentration, substrates concentration, choices of solvents ( n -alkanes), incubation time, temperature, molecular sieves (3Å × 1.5 mm), and water activity(a _w ), were optimized. The immobilized lipase (25 mg/ml) was used to perform transesterification in n -alkane(s) that resulted in approximately 73.7 mM of ethyl acetate at 55 °C in n -nonane under shaking (160 rpm) after 15 h, when vinyl acetate and ethanol were used in a equimolar ratio (100 mM each). Addition of molecular sieves (3Å × 1.5 mm) as well as effect of water activity of saturated salt solutions (KI, KCl and KNO ₃ ) to the transesterification efficiency has inhibitory effect. Batch operational stability tests indicated that immobilized lipase had retained 50% of its original catalytic activity after four consecutive batches of 15 h each.

Microbial lipases : at the interface of aqueous and non-aqueous media: a review

In recent times, biotechnological applications of microbial lipases in synthesis of many organic molecules have rapidly increased in non-aqueous media. Microbial lipases are the working horses' in biocatalysis and have been extensively studied when their exceptionally high stability in non-aqueous media has been discovered. Stability of lipases in organic solvents makes them commercially feasibile in the enzymatic esterification reactions. Their stability is affected by temperature, reaction medium, water concentration and by the biocatalyst's preparation. An optimization process for ester synthesis from pilot scale to industrial scale in the reaction medium is discussed. The water released during the esterification process can be controlled over a wide range and has a profound effect on the activity of the lipases. Approaches to lipase catalysis like protein engineering, directed evolution and metagenome approach were studied. This review reports the recent development in the field of non-aqueous microbial lipase catalysis and factors controlling the esterification/transesterification processes in organic media.

Effect of moisture content on the physical properties of fibered flaxseed

The physical properties of fibered flaxseed were investigated within moisture content varying from 6.21 to 16.29%. The length, width, thickness and geometric mean diameter increased from 4.20 to 4.44mm, 1.99 to 2.13mm, 0.91 to 0.95mm, and 1.95 to 2.06mm, respectively in the moisture content range. One thousand seed weight increased linearly from 4.22 to 4.62g. The bulk density decreased from 726.783 to 611.872kg/m3, while the true density increased from 1165.265 to 1289.341kg/m3 in the moisture content range. The porosity values of flaxseed increased linearly from 37.67 to 52.54%. The highest static coefficient of friction was found on the plywood surface, while the lowest on the stainless steel surface. The static coefficient of friction increased from 0.467 to 0.972, 0.442 to 0.864, 0.492 to 0.927, and 0.490 to 0.845 for plywood, stainless steel, aluminum sheet and galvanized iron, respectively. The angle of repose increased linearly from 25.7° to 33.8° in the moisture content range. The results are necessary for design of equipment to handling, transportation, processing, and the storage of flaxseed.

Effects of predator control on behaviour of an apex predator and indirect consequences for mesopredator suppression

1. Apex predators can benefit ecosystems through top–down control of mesopredators and herbivores. However, apex predators are often subject to lethal control aimed at minimizing attacks on livestock. Lethal control can affect both the abundance and behaviour of apex predators. These changes could in turn influence the abundance and behaviour of mesopredators.

2. We used remote camera surveys at nine pairs of large Australian rangeland properties, comparing properties that controlled dingoes Canis lupus dingo with properties that did not, to test the effects of predator control on dingo activity and to evaluate the responses of a mesopredator, the feral cat Felis catus.

3. Indices of dingo abundance were generally reduced on properties that practiced dingo control, in comparison with paired properties that did not, although the effect size of control was variable. Dingoes in uncontrolled populations were crepuscular, similar to major prey. In populations subject to control, dingoes became less active around dusk, and activity was concentrated in the period shortly before dawn.

4. Shifts in feral cat abundance indices between properties with and without dingo control were inversely related to corresponding shifts in indices of dingo abundance. There was also a negative relationship between predator visitation rates at individual camera stations, suggesting cats avoided areas where dingoes were locally common. Reduced activity by dingoes at dusk was associated with higher activity of cats at dusk.

5. Our results suggest that effective dingo control not only leads to higher abundance of feral cats, but allows them to optimize hunting behaviour when dingoes are less active. This double effect could amplify the impacts of dingo control on prey species selected by cats. In areas managed for conservation, stable dingo populations may thus contribute to management objectives by restricting feral cat access to prey populations.

6. Synthesis and applications. Predator control not only reduces indices of apex predator abundance but can also modify their behaviour. Hence, indicators other than abundance, such as behavioural patterns, should be considered when estimating a predator's capacity to effectively interact with lower trophic guilds. Changes to apex predator behaviour may relax limitations on the behaviour of mesopredators, providing enhanced access to resources and prey.

Using an Electronic Monitoring System to Link Offspring Provisioning and Foraging Behavior of a Wild Passerine

Although the costs of parental care are at the foundations of optimal-parental-investment theory, our understanding of the nature of the underlying costs is limited by the difficulty of measuring variation in foraging effort. We simultaneously measured parental provisioning and foraging behavior in a free-living population of Zebra Finches (Taeniopygia guttata) using an electronic monitoring system. We fitted 145 adults with a passive transponder tag and remotely recorded their visits to nest boxes and feeders continuously over a 2-month period. After validating the accuracy of this monitoring system, we studied how provisioning and foraging activities varied through time (day and breeding cycle) and influenced the benefits (food received by the offspring) and costs (interclutch interval) of parental care. The provisioning rates of wild Zebra Finches were surprisingly low, with an average of only one visit per hour throughout the day. This was significantly lower than those reported for this model species in captivity and for most other passerines in the wild. Nest visitation rate only partially explained the amount of food received by the young, with parental foraging activity, including the minimum distance covered on foraging trips, being better predictors. Parents that sustained higher foraging activity and covered more distance during the first breeding attempt took longer to renest. These results demonstrate that in some species matching foraging activity with offspring provisioning may provide a better estimate of the true investment that individuals commit to a reproductive attempt.

Darumbal voyaging: intensifying use of central Queensland's Shoalwater Bay islands over the past 5000 years

Island archipelagos of the tropical coast of central Queensland include the most distant offshore islands used by Aboriginal Australians. Excavations on Collins, Otterbourne and High Peak Islands, located up to 40 km from the mainland, reveal evidence of offshore voyaging and marine specialisation in the Shoalwater Bay region for at least 5200 years. A time lag of up to 3000 years between island formation and systematic island use may reflect delayed development of key marine resources. Expansion of island use commencing around 3000–3500 years ago is linked to population increases sustained by synchronous increases in marine resources. Occupational hiatuses variously between 1000 and 3000 years ago are associated with increased ENSO activity. Intensified island use within the past 1000 years is primarily a social phenomenon associated with continuing demographic pressures and the development of more coastally and marine-focused mainland groups, with settlement patterns increasingly encompassing adjacent islands. The viability of risky offshore canoe voyaging was underwritten by two key high-return subsistence pursuits – hunting green turtles and collecting turtle eggs. In addition to subsistence and quartz quarrying, a key motivation for island visitation may have been socially restricted (e.g. ceremonial) practices.

Acetylation of alcohols and phenols using continuous-flow, tungstosilicic acid-supported, monolith microreactors with scale-up capability

A highly scalable and efficient flow-system has been developed to perform the catalyzed acetylation of alcohols and phenols, such as salicylic acid, at room temperature in excellent yield. The volumetric throughput and the amount of product can be increased simply by increasing the diameter of a versatile catalytic 12-tungstosilicic acid-supported, silica monolith can be used to increase the quantity of product produced without having to changeing the optimal operatingreaction conditions.