Development of spectral band cloning techniques for soil nutrients estimation

Satellite‐based monitoring is an indispensable tool to guide soil‐specific crop management. However, it has attained little success in the estimation of soil nutrients due to the limitations incurred from inherent spectral characteristics. In this study, spectral band cloning (SBC) is developed and proposed to augment the soil nutrient predictive capabilities of broadband satellite data. Fine‐spectral channels of spectrometers were synchronized with coarse resolution of IRS satellite data to generate nutrient‐sensitive cloned IRS bands. Soil samples, collected at the time of satellite image acquisition in Lop Buri, Thailand, were analyzed both spectrally and chemically, viz., soil organic matter (OM), phosphorus, potassium and iron. The resulting SBC‐based models showed acceptable correlations, which otherwise were unattainable from raw IRS bands through prevailing models. Accuracy and validation measures showed good agreements between the measured and estimated nutrient surfaces. It is concluded that the SBC is a promising method of quantitative soil nutrient mapping, and could further be used for identification and mapping of other indiscernible biophysical parameters.     

Habitat quality–physicochemical water quality–littoral macroinvertebrate community nexus in Lugo Lake (Ethiopia): Priorities for sustainable water resources management

The integration of water quality characteristics with habplot-based habitat quality assessment score (HabQA) has received little attention in ecological quality assessment studies. This study investigated the macroinvertebrate community structure in relation with lake habitat quality and physicochemical water quality variables in Lugo Lake (Ethiopia). Twelve sampling sites (eight agricultural and four recreational) were included. The variation among macroinvertebrates data was significantly explained by HabQA score and soluble reactive phosphorus. The study revealed the greater importance of habitat quality characteristics in comparison with the other conventional physicochemical characteristics on macroinvertebrate community structure. We strongly recommend the use of HabQA system while studying macroinvertebrate community structure for a deeper understanding of the environmental functioning of tropical lakes. The results suggested the need to apply integrated and sustainable protection and management of the lake catchment (including wetlands) to enhance the ecological integrity and hence biodiversity of lakes.     

Lack of effect of olanzapine on the pharmacokinetics of a single aminophylline dose in healthy men

STUDY OBJECTIVE: To test whether olanzapine, an atypical antipsychotic, is an inhibitor of cytochrome P450 (CYP) 1A2 activity, we conducted a drug interaction study with theophylline, a known CYP1A2 substrate. DESIGN: Two-way, randomized, crossover study. SETTING: Clinical research laboratory. SUBJECTS: Nineteen healthy males (16 smokers, 3 nonsmokers). INTERVENTIONS: Because the a priori expectation was no effect of olanzapine on theophylline pharmacokinetics, a parallel study using cimetidine was included as a positive control. In group 1, 12 healthy subjects received a 30-minute intravenous infusion of aminophylline 350 mg after 9 consecutive days of either olanzapine or placebo. In group 2, seven healthy subjects received a similar aminophylline infusion after 9 consecutive days of either cimetidine or placebo. MEASUREMENTS AND MAIN RESULTS: Concentrations of theophylline and its metabolites in serum and urine were measured for 24 and 72 hours, respectively. Plasma concentrations of olanzapine and its metabolites were measured for 24 hours after the next to last dose and 168 hours after the last olanzapine dose. Olanzapine did not affect theophylline pharmacokinetics. However, cimetidine significantly decreased theophylline clearance and the corresponding formation of its metabolites. Urinary excretion of theophylline and its metabolites was unaffected by olanzapine but was reduced significantly by cimetidine. Steady-state concentrations of olanzapine (15.3 ng/ml), 10-N-glucuronide (4.9 ng/ml), and 4'-N-desmethyl olanzapine (2.5 ng/ml) were observed after olanzapine 10 mg once/day and were unaffected by coadministration of theophylline. CONCLUSION: As predicted by in vitro studies, steady-state concentrations of olanzapine and its metabolites did not affect theophylline pharmacokinetics and should not affect the pharmacokinetics of other agents metabolized by the CYP1A2 isozyme.     

Effect of starter cultures on properties of soft white cheese made from camel (Camelus dromedarius) milk

This experiment was conducted to investigate the effect of starter cultures on the physicochemical properties, texture, and consumer preferences of soft white cheese (SWC) made from camel (Camelus dromedarius) milk. The experiment was laid out in a completely randomized design with 5 treatments [starter cultures; i.e., 1 thermophilic (STI-12), 2 blended (RST-743 and XPL-2), and 2 mesophilic (R-707 and CHN-22) cultures]. Starter cultures STI-12 and RST-743 were inoculated at 37°C, whereas XPL-2, R-707, and CHN-22 were inoculated at 30°C. Camel milk inoculated using STI-12 and RST-743 cultures resulted in faster acidification than XPL-2, R-707, and CHN-22 cultures. Camel milk SWC made using STI-12 and CHN-22 cultures gave lower pH (4.54) and titratable acidity (0.59), respectively, whereas R-707 culture resulted in high cheese yield (13.44 g/100 g). In addition, high fat (20.91 g/100 g), protein (17.49 g/100 g), total solids (43.44 g/100 g), and ash (2.40 g/100 g) contents were recorded for SWC made from camel milk made using RST-743 culture. Instrumental analysis of cheese texture revealed differences in resistance to deformation in which camel milk SWC made using RST-743 culture gave higher firmness (3.20 N) and brittleness (3.12 N). However, no significant difference was observed among camel milk SWC adhesiveness made using different starter cultures. Consumer preference for appearance, aroma, taste, and overall acceptances of SWC were affected by inoculation of starter cultures. Considering curd firmness, cheese yield, compositional quality, and textures using STI-12, RST-743, and R-707, these cultures were found to be better for the manufacture of camel milk SWC.     

Biocatalytic Asymmetric Phosphorylation Catalyzed by Recombinant Glycerate‐2‐Kinase

The efficient synthesis of pure d ‐glycerate‐2‐phosphate is of great interest due to its importance as an enzyme substrate and metabolite. Therefore, we investigated a straightforward one‐step biocatalytic phosphorylation of glyceric acid. Glycerate‐2‐kinase from Thermotoga maritima was expressed in Escherichia coli, allowing easy purification. The selective glycerate‐2‐kinase‐catalyzed phosphorylation was followed by ³¹P NMR and showed excellent enantioselectivity towards phosphorylation of the d ‐enantiomer of glyceric acid. This straightforward phosphorylation reaction and subsequent product isolation enabled the preparation of enantiomerically pure d ‐glycerate 2‐phosphate. This phosphorylation reaction, using recombinant glycerate‐2‐kinase, yielded d ‐glycerate 2‐phosphate in fewer reaction steps and with higher purity than chemical routes.     

Analysis of experimentally generated friction related acoustic emission signals

Acoustic emission signals generated by sliding friction between two flat steel surfaces are characterized. A test fixture to simulate the reciprocating motion between the two surfaces under controlled conditions is developed. Sliding friction under several combinations of surface roughness, relative velocity, and normal pressure was examined. Wideband AE sensors and instrumentation were used for acquiring and analyzing the acoustic emission signals. Acoustic emission events occurred primarily during the slip portion of the stick-slip cycles. AE waveform features obtained during these experiments were indicative of the tribological conditions. Frequency components in excess of 700 kHz were seen during these experiments. The characteristics of the experimentally observed acoustic emission signals were in general agreement with earlier numerical predictions. Friction related acoustic emission signals were distinguishable from those from other sources such as fatigue crack growth. The characterization of friction related acoustic emission signals is likely to be of value in many tribological and structural health monitoring applications.     

Synthesis and luminescence in sol–gel auto-combustion-synthesized $$\hbox {CaSnO}_{3}{:}\hbox {Eu}^{3+}$$ phosphor

Undoped and Eu-doped \(\hbox {CaSnO}_{3}\) nanopowders were prepared by a facile sol–gel auto-combustion method calcined at \(800{^{\circ }}\hbox {C}\) for 1 h. The samples are found to be well-crystallized pure orthorhombic \(\hbox {CaSnO}_{3}\) structure. Photoluminescence (PL) measurements indicated that the undoped sample exhibits a broad blue emission at about 420–440 nm, which can be recognized from an intrinsic centre or centres in \(\hbox {CaSnO}_{3}\). Eu-doped \(\hbox {CaSnO}_{3}\) showed broad blue emission centred about 434 nm, a weak peak at 465 nm and a sharp intense yellow emission line at 592 nm. The emission situated at 592 nm was assigned to the f–f transition of \(^{5}\hbox {D}_{0}\rightarrow ^{7}\hbox {F}_{1}\) in \(\hbox {Eu}^{3+}\) ions. The afterglow emission and PL decay results in Eu-doped \(\hbox {CaSnO}_{3}\) phosphor, which revealed that there are at least two different traps in this phosphor. From the obtained results, \(\hbox {Eu}^{3+}\)-doped \(\hbox {CaSnO}_{3}\) phosphor could be proposed as a potential white luminescent optical material.     

Accumulation of heavy metals in the physical and biological systems of Lake Koka,Ethiopia: Implications for potential health risks

Lake Koka has several important socioeconomic uses, hydroelectric power generation, domestic water supply, irrigation, recreation and fishery. It is currently under serious threat, however, because of point and nonpoint pollution inputs. The objective of the present study was to examine the concentration of heavy metals (Mn, Cr, Pb, Zn, Cu, Ni and Cd) and their bioaccumulation, and biomagnification factors along the lake's food chain in order to assess the potential human and ecological health risks. Water, sediment and plankton samples were collected from seven sampling sites and fishes were purchased on site from fishers. The analyses were performed using a graphite furnance atomic absorption spectrophotometer. Heavy metals levels in the sediment samples were ranked in the order of Mn > Cr > Pb > Zn > Cu > Ni > Cd. Similarly, the metal concentration in the fish muscles was Cr > Cu > Pb > Cd. The sediment bioaccumulation factor (<1) and water bioaccumulation factor (>1) for Cd, Pb and Cr indicated the lake water exhibited higher concentrations than the sediment. In parallel, the Cr biomagnification factor for zooplankton, catfish, Nile tilapia and common carp was 1.63, 1.18, 1.36 and 2.28, respectively. The Cr concentrations at the Modjo (or Mojo) Upstream, Modjo Downstream and Kentare sites, and the Pb concentrations at riverine sites were above the permissible limits established by the World Health Organization. Cr ranked as fish species > zooplankton > phytoplankton, being above the permissible limits in catfish, Nile tilapia and common carp. Generally, the weekly intake estimates were considerably lower than the tolerable human intake values provided by WHO and others. However, Cr biomagnified along the trophic levels ultimately reaching the top consumers, with Cr (VI) being carcinogenic. The lake is a major fishery source, indicating care must be taken in regard to the weekly intake of the fishes, particularly common carp.     

Measurement of caffeine in coffee beans with UV/vis spectrometer

In this research work using UV/vis spectrophotometer the molar decadic absorption coefficients and transitional dipole moment of pure caffeine in water and dichloromethane were obtained at 272 and 274.7 nm. The molar decadic absorption coefficients of caffeine in water and dichloromethane at these wavelengths are 1115 and 1010 m² mol⁻¹, respectively. The calculated values for the transitional dipole moment of caffeine in water and in dichloromethane are 10.40 × 10⁻³⁰ and 10.80 × 10⁻³⁰ C m, respectively. After characterizing caffeine in water and dichloromethane, fast and simple methods were developed that enable to quantify the content of caffeine in coffee beans. The methods helped in extracting caffeine from coffee dissolved in water by dichloromethane, and Gaussian fit was applied to eliminate the possible interference with the caffeine spectra.     

Olanzapine 10-N-glucuronide. A tertiary N-glucuronide unique to humans

In humans, a major metabolite of the atypical antipsychotic olanzapine in the plasma and in the urine was found to be an N-glucuronide. Unexpectedly, the glucuronic acid moiety was linked through a nitrogen of the benzodiazepine nucleus of olanzapine by way of a secondary amine linkage, rather than through a nitrogen on the piperazine substituent of the nucleus, to give a quaternary ammonium glucuronide. Derivatization with phenylisothiocyanate to yield a thiourea adduct indicated that conjugation occurred via a secondary amine. Subsequently, mass spectrometry and nuclear magnetic resonance studies with the isolated metabolite and later with the synthesized metabolite indicated that the glucuronide was linked at the 10- position of olanzapine. This phase 2 metabolite was only detected in the plasma and urine of human subjects and not in mice, rats, or monkeys; a trace of this metabolite was detected in dog urine. The N-10 glucuronide was resistant to enzymatic and base hydrolysis but was cleaved under acidic conditions. Formation of an N-glucuronide metabolite directly with the benzodiazepine nucleus has not previously been reported.