A search for companions to nearby brown dwarfs: the binary DENIS-P J1228.2-1547

Hubble Space Telescope imaging observations of two nearby brown dwarfs, DENIS-P J1228.2-1547 and Kelu 1, made with the near-infrared camera and multiobject spectrometer (NICMOS), show that the DENIS object is resolved into two components of nearly equal brightness with a projected separation of 0.275 arc second (5 astronomical units for a distance of 18 parsecs). This binary system will be able to provide the first dynamical measurement of the masses of two brown dwarfs in only a few years. Upper limits to the mass of any unseen companion in Kelu 1 yield a planet of 7 Jupiter masses aged 0. 5 x 10(9) years, which would have been detected at a separation larger than about 4 astronomical units. This example demonstrates that giant planets could be detected by direct imaging if they exist in Jupiter-like orbits around nearby young brown dwarfs.     

Determination of Pomological and Morphological Characteristics and Chemical Compositions of Local Apple Varieties Grown in Gumushane,Turkey

The present study was conducted in order to determine the pomological and morphological characteristics and chemical compositions of some local apple varieties grown in Gumushane. As a result of field work in Gumushane province, sixteen different apples, which are Summer Apple, English apple, Green Belly, Black Belly and Yellow Belly Apples, Amasya Marble, Bey Apple, Chest Apple, Mahsusa, Arabian Girl, Willow Apple, Tav?anba??, Yellow H?d?r, Local Marble, Bride Apple, and Fatty Apple were collected in order to analyze. The average results of pomological and morphological properties and chemical compositions were obtained as following: fruit mass; 127.36 g, fruit width; 65.23 mm, fruit length; 57.30 mm, fruit stalk thickness; 2.17 mm, fruit stalk length; 17.63 mm, stalk pit depth; 12.75 mm, flower pit depth; 10.29 mm, fruit firmness; 13.79 kg/cm², seed house width; 15.89 mm, seed house length; 17.39 mm, number of seeds; 4.3, water soluble dry matter content; 14.53?%, ash content; 1.11?%, pH; 3.8, titratable acidity; 0.69 g/L, water content; 83.8?%, reducing sugar; 5.04 g/100 g, sucrose; 2.25 g/100 g, and the amount of total sugars; 7.29 g/100. The fruit peel color was determined by considering the light transmittance (L). The average L values were ranged between 112.06 and 66.32. On the other hand among the mineral elements, potassium and manganese amounts were determined as the highest and the lowest, respectively.     

Optimizing fertilizers doses and their effects on photosynthesis and biomass yield of Hibiscus cannabinus cultivated on BRIS soil

In tropical climate, huge amount of fertilizer need to be used for the cultivation of kenaf (Hibiscus cannabinus L.) in Beach Ridges Interspersed with Swales (BRIS) soil, however this approach is not cost effective and environmental friendly. Therefore, the optimizing of fertilizer rate for BRIS soils and selection of suitable soil amendments are crucial to get a higher yield. In this study, the effects of different combinations of urea, chicken manure and biochar on soil properties, growth performance and physiological characteristics of kenaf cultivated on the BRIS soil were investigated. Eight treatments were conducted namely: control (T1), biochar (T2), chicken manure (T3), urea (T4), chicken manure + urea (T5), biochar + chicken manure (T6), urea + biochar (T7) and biochar + chicken manure + urea (T8). The biomass and physiological characteristics of kenaf were recorded every month, while the soil was analyzed following a standard laboratory procedure. The application of organic and inorganic fertilizer (urea) significantly increased the nutrient content of the soil compared to the T1, whereas T3 showed the highest pH, cation exchange capacity, and exchangeable bases (Na, Mg, Ca). However, the mixing of biochar with organic and inorganic fertilizers showed the highest plant height, diameter of stem and number of leaves as well as dry biomass compared to other treatments. Furthermore, the application of nitrogen fertilizer significantly increased the photosynthesis rate and stomatal conductivity. The results suggest that the mixing of biochar with organic and inorganic fertilizers represents an effective approach for the cultivation of kenaf in tropical climate.     

Artificial neural network analysis of lipase-catalyzed synthesis of sugar alcohol ester

Artificial neural network (ANN) analysis of immobilized Candida antarctica lipase B-catalyzed esterification of palmitic acid with xylitol was carried out. Temperature, time, amount of enzyme, amount of molecular sieve, substrate molar ratio and volume of solvent were the six important parameters used as the inputs of the network trained by Levenberg-Marquardt (LM) algorithm. After evaluating different ANN configurations, the best network was found to be consisted of two hidden layers with six and seven neurons in the first and second layers respectively, using a hyperbolic tangent sigmoid transfer function. The coefficient of determination (R²) and mean square error (MSE) values between the actual and predicted responses were 1 and 1.5025e−24 for the training and 0.97239 and 0.03259 for the testing datasets. The results indicate the good generalization performance of the neural network model and its capability to predict the conversion of the substrates.     

Effects of herbage intake on goat performance in the mediterranean type natural pastures

This study aimed at identifying changes in natural pastures during the grazing season and investigating the effects of these changes on pasture feeding potential for high yielding dairy goats. During the study, 12 dairy goats were grazed on a 1.5 ha natural pasture for three months from April to June in 2003, 2004 and 2005. The goats were fed 0.5 kg/day of concentrate as a supplement during the grazing season. Botanical composition, herbage production and intake, crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of the pasture were determined. Live weight, milk yield, milk dry matter (DM) and fat content of the goats were monitored. The data were analyzed using a linear model, which evaluated the effects of grazing seasons in each year. Based on the three-year average, 87% of pasture was herbaceous plants and the remaining was shrubs in DM basis with Cistus creticus , Quercus ithaburensis , Pistacia atlantica and Asparagus acutifolius being the major shrub species. The herbage yield in June was significantly lower than in other months in all years ( P  = 0.001). In all experimental years, the CP content of the pasture decreased but the structural carbohydrates increased as the grazing season proceeded. While live weight was not affected by grazing periods except for 2004 ( P  = 0.001), milk yield significantly decreased with advancing grazing period ( P  = 0.001). The results of the present study indicate that natural pasture has a supportive effect in April and May on the milk yield of lactating goats which are in mid-lactation, and suggested that supplementary feeding is required in consecutive grazing periods.     

Gene flow from transgenic wheat and barley under field conditions

In this study the frequency and distance of gene flow from transgenic wheat (Triticum aestivum) and barley (Hordeum vulgare) to non-transgenic wheat and barley crops was investigated under local field conditions. Trials were conducted in the Australian Capital Territory (ACT) and in South Australia (SA). Gene flow from transgenic wheat was confirmed at frequencies of 0.012% and 0.0037% in the ACT and SA, respectively. In both trials gene flow occurred over distances of less than 12 m. Gene flow was also detected from transgenic barley at a frequency of 0.005%, over a distance of less than 12 m. The results show that under Australian field conditions, gene flow occurs at extremely low frequencies and over very short distances. Physical separation of transgenic and non-transgenic cereal crops by greater than 12 m should ensure that contamination of adjacent non-transgenic cereal crops remains less than 0.02%, well below the level permitted under Australian regulations.     

Natural enemies of the bagworm, Metisa plana Walker (Lepidoptera: Psychidae) and their impact on host population regulation

The bagworm, Metisa plana (Lepidoptera: Psychidae) is an important pest of oil palm, capable of being present as outbreak, which could cause a crop loss of up to 44%. Circumstantial evidence has long indicated that natural enemies play an important role in the population regulation of this pest. However, direct field data on the enemies themselves has been lacking.

A field study on a population of M. plana was made at PORIM Kluang, Johor, Malaysia from September 1988 to December 1992. The population of bagworm was initially high (late 1988, up to 38 larvae/frond, and in early 1990, up to 30 larvae/frond) but remained extremely low in the subsequent period (< 10 larvae/frond).

The population of M. plana was affected by both primary and secondary parasitoids and predators. Among the primary parasitoids, Dolichogenidea metesae was the most pronounced larval parasitoid of M. plana. This parasitoid was commonly attacked by hyperparasitoids, particularly Pediobius anomalus and Pediobius imbreus. A hypothetical life table constructed from the mortality figures of the declining part of the population during late 1988 confirmed that the natural enemies played a key role in suppressing the bagworm population.

The present study confirmed that overlapping generations were vital for the persistence of parasitoids of M. plana. The paper also suggested a possible need of alternative hosts. An active predator, Callimerus arcufer was also commonly encountered.     

Optimization of lipase-catalyzed synthesis of palm amino acid surfactant using response surface methodology (RSM)

Amino acid surfactants are high-value surfactants which have excellent emulsifying characteristics and minimal toxicity to the living body. Enzymatic synthesis of palm kernel amino acid surfactant was optimized by response surface methodology (RSM) using palm kernel olein (PKO) and l(+)-lysine catalyzed by Lipozyme RM IM. The reaction was performed in batch mode stirred tank reactor (STR) with one multi-bladed impeller. A central composite rotatable design (CCRD) was employed to evaluate the interactive effects of various parameters. The parameters were temperature (A): (40.00–70.00 °C), impeller speed (B): (100.00–400.00 rpm), substrates ratio (C): (1.00–4.00 mmol) and enzyme amount (D): (5.00–8.00 g). The optimum condition derived via RSM at fixed reaction time of 24 h was temperature; 47.50 °C, impeller speed; 323.96 rpm, substrates ratio; 3.25 mmol and enzyme amount; 7.25 g. The experimental yield was 89.03% under the optimum condition, which compared well with the maximum predicted value of 93.77%.