A modeling study of soil temperature and moisture effects on population dynamics of Paronychiurus kimi (Collembola: Onychiuridae)

The effect of soil moisture on population dynamics of Paronychiurus kimi (Collembola) was examined by combining an empirical soil moisture model with a temperature-sensitive, stage-structured population model. Field observations of soil temperature were used to drive the population model, and simulations were compared to field observations of juvenile and adult densities. Simulations without soil moisture effects produced stable, interyear population dynamics and a significant correlation between simulations and observations (n=12, r ²=0.40, P<0.05) but overestimated densities during much of the year. Adding responses to soil moisture improved the fit between simulations and observations (n=13, r ²=0.40), suggesting that soil moisture is a major limiting factor on field populations of P. kimi. Moreover, an observed temporary decline in field populations during spring could be explained partly by the effects of an herbicide, paraquat (N,N′-dimethyl-gamma,gamma′-bipyridylium dichloride) (r ²=0.45), suggesting that paraquat imposes additional limits on collembolan populations.     

Preparation and characterization of water/oil and water/oil/water emulsions containing biopolymer-gelled water droplets

The purpose of this study was to create water-in-oil (W/O) and water-in-oil-in-water (W/O/W) emulsions containing gelled internal water droplets. Twenty weight percent W/O emulsions stabilized by a nonionic surfactant (6.4 wt % polyglycerol polyricinoleate, PGPR) were prepared that contained either 0 or 15 wt % whey protein isolate (WPI) in the aqueous phase, with the WPI-containing emulsions being either unheated or heated (80 degrees C for 20 min) to gel the protein. Optical microscopy and sedimentation tests did not indicate any significant changes in droplet characteristics of the W/O emulsions depending on WPI content (0 or 15%), shearing (0-7 min at constant shear), thermal processing (30-90 degrees C for 30 min), or storage at room temperature (up to 3 weeks). W/O/W emulsions were produced by homogenizing the W/O emulsions with an aqueous Tween 20 solution using either a membrane homogenizer (MH) or a high-pressure valve homogenizer (HPVH). For the MH the mean oil droplet size decreased with increasing number of passes, whereas for the HPVH it decreased with increasing number of passes and increasing homogenization pressure. The HPVH produced smaller droplets than the MH, but the MH produced a narrower particle size distribution. All W/O/W emulsions had a high retention of water droplets (>95%) within the larger oil droplets after homogenization. This study shows that W/O/W emulsions containing oil droplets with gelled water droplets inside can be produced by using MH or HPVH.     

Pyrolysis GC-MS analysis of tars formed during the aging of wood and bamboo crude vinegars

Constituents of tars formed during the aging of bamboo (Phyllostachys pubescens), oak (Quercus serrata), and pine (Pinus densiflora) wood crude vinegars were analyzed by pyrolysis-gas chromatography (Py-GC) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) to investigate their origination. The pyrolysate of tars obtained from the wood and bamboo crude vinegars were almost identical and were primarily composed of phenolic compounds and aromatic hydrocarbons. In addition, during the aging of model wood vinegar that was prepared for comparison with the wood and bamboo vinegars, a marked decrease was observed in the levels of phenolic compounds (phenol; o-, p-, and m-cresol; and syringol). Furthermore, the Py-GC-MS results of the tars produced during the aging of the model wood vinegar revealed that phenolic compounds were primarily responsible for the formation of tar during the aging of wood and bamboo crude vinegars. Pyrroles, which may be derived from the primary pyrolysate of amino acids, nitrogen-containing extracts, or both, were also partially involved in the formation of tar during the aging period.     

Effect of dietary substitution of sea tangle (ST), Laminaria japonica with rice bran (RB) on growth and body composition of juvenile abalone (Haliotis discus)

Dietary substitution effect of sea tangle (ST) with rice bran (RB) on growth and carcass composition of juvenile abalone (Haliotis discus) was determined. Juvenile abalone was acclimated to the experimental conditions for 4 weeks. Seventy juvenile abalone averaging 0.43 g were randomly distributed into each of the 18, 70 L plastic rectangular containers. The experimental diets were fed to abalone once a day at a satiation level with a little leftover. The feeding trial lasted for 16 weeks. Survival of abalone was not affected by dietary substitution of ST with RB. However, weight gain of abalone fed the RB40 diet was higher than that of abalone fed the all other diets except for the RB0 diet. No significant difference in weight gain was found in abalone fed between the RB0 and RB100 diets. SGR of abalone fed the RB40 diet was higher than that of abalone fed the all other diets. Also SGR of abalone fed the RB0 diet was higher than that of abalone fed the RB100 diet, but not different from that of abalone fed the RB20, RB60 and RB80 diets. Moisture, crude protein and ash content of the soft body of abalone were affected by dietary substitution of ST with RB. In conclusion, the 100% ST could be substituted with RB without a retardation of weight gain of abalone when the 20% ST was included into the experimental diet. However, the best growth performance was obtained in abalone fed the RB40 diet substituting 40% ST with RB.     

Variations in chemical characteristics and pulpability within jute plant (Chorcorus capsularis)

The differences in morphological and chemical characteristics and pulpability of core and bark fiber of jute at different position, top, middle and bottom were studied. The fiber length at the middle part of both bark and core was longer than the top and bottom part. With increasing height from bottom to top lignin content is decreased and α-cellulose content increased. The bark had higher α-cellulose and lower lignin than core. The bark produced nitrobenzene oxidation products with larger syringaldehyde/vanillin (S/V) ratios than the core. The yields of nitrobenzene oxidation products in bark were higher than core. The analysis of neutral sugars suggested that xylose is the predominant sugar of hemicellulose in both bark and core. The bark had higher glucose and lower xylose as compared to core. Under identical conditions of pulping, bark gave higher pulp yield and lower kappa number than core. The bark pulp showed better bleachability than core pulp. The higher tensile index in core pulp and higher tear index in bark pulp were observed.     

Pathological characteristics of olive flounder <Emphasis Type="Italic">Paralichthys olivaceus</Emphasis> experimentally infected with <Emphasis Type="Italic">Streptococcus parauberis</Emphasis>

Pathological characteristics of olive flounder Paralichthys olivaceus experimentally infected with Streptococcus parauberis were studied. Various stressful conditions, aeration and netting stress in particular, led to induced mortality by S. parauberis. Netting stress-induced mortality was positively correlated to bacterial dose and stressful conditions. Inflammation of the heart and pericarditis was the major pathological change observed in olive flounder experimentally infected with S. parauberis. During the infected period, the number of bacteria in the infected olive flounder was recorded over time. S. parauberis remained in all fish organs tested, especially in the heart and brain.     

Effect of tree age on the cellulose structure of Nalita wood (Trema orientalis)

The change of crystalline structure of Nalita cellulose with tree age has been studied using X-ray diffraction and FT-IR spectroscopy. The proportion of crystallinity and crystal size were increased with tree age. FT-IR spectroscopy showed that the Nalita cellulose was a monoclinic unit cell structure (I_β). The proportion of crystallinity and crystal size of the 30-month-old Nalita wood was higher as compared to aspen wood. The degree of polymerization (DP) of Nalita cellulose of different ages has also been studied. The DP of cellulose increased with tree age. The DP of Nalita cellulose was lower than that of aspen cellulose. The percentage of glucose in Nalita wood increased with tree age.     

ALLEVIATION OF ALUMINUM IN ACIDIC SOILS AND ITS EFFECT ON GROWTH OF HYBRID AND CLONAL OIL PALM SEEDLINGS

Aluminum (Al) toxicity is an important factor in limiting crop production. The present study examined the Al alleviation effects on the growth of hybrid (breeding) and clonal (tissue culture) of D × P oil palm seedlings. The experiment was performed using calcium carbonate (CaCO₃), and ground magnesium limestone (GML) and magnesium carbonate (MgCO₃) as soil-amendments at different rates in Colombia and Malaysia, respectively. The effects of the treatments were evaluated monthly on vegetative variables and visual symptoms. Chlorophyll concentrations were recorded in Malaysia at the fifth month growing stage. The different amendments improved the soil fertility and it was reflected on better performance of shoot and root growth. The chlorophyll content in the frond number 3 for both materials enhanced significantly when Al saturation was low (0–30%). The results from the experiment revealed the importance of neutralization of Al in reducing its toxicity in oil palm.     

外源植物激素对东方山羊豆响应盐胁迫的调控效应初探

为确定东方山羊豆(Galega orientalis)种子萌发及苗期耐盐性,明确在盐胁迫条件下,植物生长激素对东方山羊豆种子萌发及苗期生理特性的影响,分析比较了不同NaCl浓度（0、25、50、100、150、200 mmol·L-1）梯度及不同植物生长激素处理下的东方山羊豆种子萌发率、幼苗脯氨酸、丙二醛和叶绿素含量等指标的差异。结果表明,东方山羊豆种子和幼苗对盐胁迫比较敏感,东方山羊豆能够适应50 mmol·L-1浓度以内NaCl胁迫,50 mmol·L-1浓度以内NaCl对种子萌发及幼苗生长影响小,随着NaCl浓度的增高,种子发芽率和幼苗丙二醛、叶绿素含量显著降低,脯氨酸含量显著增加;GA3可以提高150 mmol·L-1浓度以内NaCl胁迫条件下东方山羊豆的种子萌发率;NAA适合调控东方山羊豆幼苗在中、低盐浓度下的生长。