Vermicomposting potentiality of Perionyx excavatus for recycling of waste biomass of Java citronella--an aromatic oil yielding plant

Laboratory investigation on vermicomposting efficacy of Perionyx excavatus for recycling of distillation waste biomass of java citronella (Cymbopogon winterianus Jowitt) was carried out in two seasonal trials i.e. summer and winter periods. The experiment was conducted in earthen pots using a mixture of citronella waste material and cowdung in the proportion of 5:1. A control treatment without earthworms was setup for comparison of the results. The vermicompost had shown 5.8 folds reduction in C/N ratio and 5.6 folds enhancement in ash content. The nutrient contents (N, P, K, Ca and Mg) in the vermicompost had increase in the range of 1.2 - 4.1 fold than the initial level. The FT-IR spectra of the vermicompost confirmed increase in nitrogen rich compounds and decrease in aliphatic/aromatic compounds as compared to the initial level of the biowaste materials. The vermicomposting process is influenced by seasonal variation and summer was more productive than winter.     

Taxonomic status and composition of stem bark oil of a variant of Cinnamomum bejolghota (Lauraceae) from Northeast India

Cinnamomum bejolghota var. jarainum , var. nov., is illustrated and described as new. The essential oil composition of stem bark oil of the taxon is also analyzed and reported.     

Microencapsulation of Zanthoxylum limonella oil (ZLO) in glutaraldehyde crosslinked gelatin for mosquito repellent application

Glutaraldehyde (GA) crosslinked gelatin (G) microcapsules containing Zanthoxylum limonella oil (ZLO) were prepared by coacervation technique. The effect of various parameters such as variation of oil-loading, gelatin concentration and degree of crosslinking on release rate of oil were studied. Scanning electron microscopy (SEM) was used to understand the surface characteristics of microcapsules. FTIR-results indicated the absence of any significant interaction between polymer and oil.     

Purification and characterization of phenoloxidase from the hemolymph of healthy and diseased Antheraea assamensis Helfer (Lepidoptera: Saturniidae): Effects of certain biological components and chemical agents on enzyme activity

In the current study, a dimeric phenoloxidase (PO) from the hemolymph of healthy and diseased (pebrine infected) larvae of Antheraea assamensis Helfer was extracted and purified. The protein was subjected to purification using Sephacryl S‐100 and CM Sepharose chromatography. The enzyme comprised of two subunits of ~76.8 and 76 kDa that showed PO activity in 6 mM l ‐3,4‐dihydroxyphenylalanine (L ‐DOPA) and 8 mM catechol but not in hydroquinone. Optimum temperature for PO activity was 30°C in l ‐DOPA and 37°C in catechol. Optimum pH ranged from 6.8 to 7.0 in L ‐DOPA and 7.0–7.2 in catechol. Specific activity of the purified PO from healthy larvae was 53.9 µM/min per mg of protein per ml in L ‐DOPA and 50.77 µM/min per mg of protein per ml in catechol. Specific activity of PO from diseased larvae was 30.0 µM/min per mg of protein per ml in L ‐DOPA and 28.55 µM/min per mg of protein per ml in catechol. Purification fold was 3.27–4.21 for healthy and 2.38–2.56 for diseased fractions. The enzyme showed the Michaelis constant (K_m) of 2.46–2.85 mM for healthy and diseased fractions in L ‐DOPA. In catechol K_m of 9.23–17.71 mM was observed. Peptidoglycan was the best activator of purified PO from both healthy and diseased fractions. Interactions between controls and activators appeared statistically significant (F = 767.5; df = 3; P < 0.0001). Na⁺, K⁺, and Cu²⁺ increased, whereas Ca²⁺, Zn²⁺, Mg²⁺, and Co²⁺ decreased PO activity. The overall interactions appeared highly significant (F = 217.0; df = 27; P < 0.0001). Kojic acid, dithiothreitol, thiourea, phenylthiourea, carbendazim, N‐bromosuccinimide, N,N,N′,N′‐tetraacetic acid, and diethyldithiocarbamate inhibited PO activity.     

Induction of oscillatory ventilation pattern using dynamic modulation of heart rate through a pacemaker

For disease states characterized by oscillatory ventilation, an ideal dynamic therapy would apply a counteracting oscillation in ventilation. Modulating respiratory gas transport through the circulation might allow this. We explore the ability of repetitive alternations in heart rate, using a cardiac pacemaker, to elicit oscillations in respiratory variables and discuss the potential for therapeutic exploitation. By incorporating acute cardiac output manipulations into an integrated mathematical model, we observed that a rise in cardiac output should yield a gradual rise in end-tidal CO2 and, subsequently, ventilation. An alternating pattern of cardiac output might, therefore, create oscillations in CO2 and ventilation. We studied the effect of repeated alternations in heart rate of 30 beats/min with periodicity of 60 s, on cardiac output, respiratory gases, and ventilation in 22 subjects with implanted cardiac pacemakers and stable breathing patterns. End-tidal CO2 and ventilation developed consistent oscillations with a period of 60 s during the heart rate alternations, with mean peak-to-trough relative excursions of 8.4 +/- 5.0% (P < 0.0001) and 24.4 +/- 18.8% (P < 0.0001), respectively. Furthermore, we verified the mathematical prediction that the amplitude of these oscillations would depend on those in cardiac output (r = 0.59, P = 0.001). Repetitive alternations in heart rate can elicit reproducible oscillations in end-tidal CO2 and ventilation. The size of this effect depends on the magnitude of the cardiac output response. Harnessed and timed appropriately, this cardiorespiratory mechanism might be exploited to create an active dynamic responsive pacing algorithm to counteract spontaneous respiratory oscillations, such as those causing apneic breathing disorders.     

Irradiance influences tea leaf (<Emphasis Type="Italic">Camellia sinensis</Emphasis> L.) photosynthesis and transpiration

Rates of net photosynthesis (P _N) and transpiration (E), and leaf temperature (T_L) of maintenance leaves of tea under plucking were affected by photosynthetic photon flux densities (PPFD) of 200–2 200 μmol m⁻² s⁻¹. P _N gradually increased with the increase of PPFD from 200 to 1 200 μmol m⁻² s⁻¹ and thereafter sharply declined. Maximum P _N was 13.95 μmol m⁻² s⁻¹ at 1 200 μmol m⁻² s⁻¹ PPFD. There was no significant variation of P _N among PPFD at 1 400–1 800 μmol m⁻² s⁻¹. Significant drop of P _N occurred at 2 000 μmol m⁻² s⁻¹. PPFD at 2 200 μmol m⁻² s⁻¹ reduced photosynthesis to 6.92 μmol m⁻² s⁻¹. PPFD had a strong correlation with T_L and E. Both T_L and E linearly increased from 200 to 2 200 μmol m⁻² s⁻¹ PPFD. T_L and E were highly correlated. The optimum T_L for maximum P _N was 26.0 °C after which P _N declined significantly. E had a positive correlation with P _N.     

Methane emission associated with anatomical and morphophysiological characteristics of rice (Oryza sativa) plant

Plant-mediated transport is the primary route of methane (CH(4)) emission from the reduced paddy field to the aboveground atmosphere. Experiments were conducted at North Bank Plain Agro-climatic Zone of Assam, India, during monsoon rice-growing season (July to December 2006) to elucidate the influences of anatomical and morphophysiological characteristics of rice (Oryza sativa L.) cultivars on methane emission from submerged agroecosystem. Ten rice cultivars were grown in light-textured loamy soil under rainfed uniform field condition. Among the 10 cultivars, 5 were traditional rice genotypes commonly grown in the agroclimatic zone and the other 5 were improved high-yielding varieties. Wide variation in CH(4) flux was recorded among the rice cultivars, which may be regulated by the difference in anatomical and morphophysiological characteristics of rice plant. Microscopic analysis of stem portion showed that high- and medium-CH(4)-emitting cultivars recorded higher size of the medullary cavity. Leaf area and transpirational rates were also found to be higher in high-CH(4)-emitting varieties. Scanning electron microscopic analysis revealed higher stomatal frequencies in high-methane-emitting cultivars. Data presented in this study suggest that variation in anatomical and morphophysiological characteristics among different rice genotypes may influence CH(4) emission from paddy fields.     

Effect of carbon and nitrogen sources on neutral proteinase production byPseudomonas aeruginosa

A strain ofPseudomonas aeruginosa from soil produced large quantitaties of extracellular neutral proteinase and could utilize several organic substances as carbon and nitrogen sources for enzyme production. The growth media required the presence of a high amount of phosphate when glucose was the carbon source. The intermediates of citric-acid cycle acids supported the proteinase production more than any other carbon sources. However, complex nitrogenous substances supported enzyme production more efficiently. Higher concentration of casamino acids suppressed the proteinase synthesis.     

Simple Method for Inducing Ascospore Formation in Yeasts

A new method for inducing ascospore formation in yeasts is described and compared with conventional methods for its performance. The method has the advantage of simplicity, reproducibility, and saving of time.