Evaluation of commercial soil health tests using a medium-term cover crop experiment in a humid,temperate climate

Plant and Soil - Microbial-driven biogeochemical cycles of phosphorus (P) in wetlands subjected to global climate warming result in a downstream eutrophication risk. However, how warming influences...     

Timely synthesis of the adenovirus type 5 E1B 55-kilodalton protein is required for efficient genome replication in normal human cells

Previous studies have indicated that the adenovirus type 5 E1B 55-kDa protein facilitates viral DNA synthesis in normal human foreskin fibroblasts (HFFs) but not in primary epithelial cells. To investigate this apparent difference further, viral DNA accumulation was examined in primary human fibroblasts and epithelial cells infected by the mutant AdEasyE1Δ2347, which carries the Hr6 frameshift mutation that prevents production of the E1B 55-kDa protein, in an E1-containing derivative of AdEasy. Impaired viral DNA synthesis was observed in normal HFFs but not in normal human bronchial epithelial cells infected by this mutant. However, acceleration of progression through the early phase, which is significantly slower in HFFs than in epithelial cells, eliminated the dependence of efficient viral DNA synthesis in HFFs on the E1B 55-kDa protein. These observations suggest that timely synthesis of the E1B 55-kDa protein protects normal cells against a host defense that inhibits adenoviral genome replication. One such defense is mediated by the Mre11-Rad50-Nbs1 complex. Nevertheless, examination of the localization of Mre11 and viral proteins by immunofluorescence suggested that this complex is inactivated similarly in AdEasyE1Δ2347 mutant-infected and AdEasyE1-infected HFFs.     

Ventricular pacing – Electromechanical consequences and valvular function

Although great strides have been made in the areas of ventricular pacing, it is still appreciated that dyssynchrony can be malignant, and that appropriately placed pacing leads may ameliorate mechanical dyssynchrony. However, the unknowns at present include:1. The mechanisms by which ventricular pacing itself can induce dyssynchrony;2. Whether or not various pacing locations can decrease the deleterious effects caused by ventricular pacing;3. The impact of novel methods of pacing, such as atrioventricular septal, lead-less, and far-field surface stimulation;4. The utility of ECG and echocardiography in predicting response to therapy and/or development of dyssynchrony in the setting of cardiac resynchronization therapy (CRT) lead placement;5. The impact of ventricular pacing-induced dyssynchrony on valvular function, and how lead position correlates to potential improvement.This review examines the existing literature to put these issues into context, to provide a basis for understanding how electrical, mechanical, and functional aspects of the heart can be distorted with ventricular pacing. We highlight the central role of the mitral valve and its function as it relates to pacing strategies, especially in the setting of CRT. We also provide future directions for improved pacing modalities via alternative pacing sites and speculate over mechanisms on how lead position may affect the critical function of the mitral valve and thus overall efficacy of CRT.     

An experimental and theoretical approach to 5alpha-cholestan-6-spiro-1',2',4'-triazolidine-3'-one

The 5alpha-cholestan-6-one semicarbazone (1) on reaction with hydrogen peroxide at 0 degrees C affords selectively 5alpha-cholestan-6-spiro-1',2',4'-triazolidine-3'-one. (2) The structural assignment of the product was confirmed on the basis of its elemental, analytical and spectral analysis. The Hartree-Fock method using 6-31G* basis set was employed in order to explore the reaction mechanism. The results of the computational study show that the reaction proceeds through two radical intermediates formation. The different characteristics involved during the reaction were explained, firstly, the lower energy conformation of each molecule using total energy, hardness and dipole moment, and secondly, the explanation of the free radical mechanism, using frontier molecular orbital (FMO) theory, encoded electrostatic potential, spin electronic density and atomic charges. The localization of highest occupied molecular orbital (HOMO) or alpha-HOMO, lowest unoccupied molecular orbital (LUMO) or alpha-LUMO and the flow of atomic charges are in good agreement to support the present mechanism of the reaction. Stability and feasibility of all the optimized structures were supported by their respective fundamental frequencies and energy minima.     

Solid-State Fermentation with Trichoderma reesei for Cellulase Production

Cellulase yields of 250 to 430 IU/g of cellulose were recorded in a new approach to solid-state fermentation of wheat straw with Trichoderma reesei QMY-1. This is an increase of ca. 72% compared with the yields (160 to 250 IU/g of cellulose) in liquid-state fermentation reported in the literature. High cellulase activity (16 to 17 IU/ml) per unit volume of enzyme broth and high yields of cellulases were attributed to the growth of T. reesei on a hemicellulose fraction during its first phase and then on a cellulose fraction of wheat straw during its later phase for cellulase production, as well as to the close contact of hyphae with the substrate in solid-state fermentation. The cellulase system obtained by the solid-state fermentation of wheat straw contained cellulases (17.2 IU/ml), β-glucosidase (21.2 IU/ml), and xylanases (540 IU/ml). This cellulase system was capable of hydrolyzing 78 to 90% of delignified wheat straw (10% concentration) in 96 h, without the addition of complementary enzymes, β-glucosidase, and xylanases.     

Genetic distances among the diabetic “Punjabis” and comparative populations from North India

Non-insulin dependent diabetes mellitus (NIDDM) is emerging as a major non-communicable disease in developing countries. Using principal component and Mahalanobis' generalized distance analyses, we examined gene frequency data at 3 polymorphic loci in sedentee urban controls, urban diabetics of the “Punjabi” population along with other comparative populations from North India. Mahalanobis generalized distance analysis suggests relative dissimilarity in the “Punjabi” disease subgroups indicating possible genetic heterogeneity. The genetic distance analysis also identified clinal variation along a north-west to south-east axis in North India.     

SCP production by Chaetomium cellulolyticum,a new thermotolerant cellulolytic fungus

Chaetomium cellulolyticum, a newly isolated cellulolytic fungus, showed 50–100% faster growth rates and over 80% more final biomass-protein formation than Trichoderma viride, a well-known high cellulase-producing cellulolytic organism, when cultivated on Solka-floc (a purified, predominantly amorphorous form of cellulose) or partially delignified sawdust (consisting of a mixture of hardwoods) as the sole-carbon source in the fermentation media. However, in both cases, T. viride produced much higher quantities of free cellulases at faster rates and also degraded more substrate than C. cellulolyticum. It is concluded that the synthesis mechanisms and/or the nature of the cellulase complexes of the two types of organisms are quite different such that C. cellulolyticum is more optimal for single-cell protein (SCP) production, while T. viride is more optimal for the production of extracellular cellulases. It was also found that the amino acid composition of C. cellulolyticum is generally better than that of T. viride and compares favorably with those of the FAO reference protein, alfalfa, and soya meal. In addition, preliminary feeding trials on rats have shown no adverse effects of the SCP produced by C. cellulolyticum fermentations.     

Shifting clinal patterns of stress resistance traits in Drosophila ananassae

Drosophila ananassae, a desiccation and cold sensitive species, is abundant along the latitudinal gradient of the Indian subcontinent. Analysis of seasonally varying wild-caught flies showed two independent patterns of melanisation: (1) narrow to broad melanic stripes on three anterior abdominal segments only; (2) a novel body color pattern (dark vs. light background). We investigated the degree to which these two melanisation systems vary; first with latitude and secondly among seasons. There is a shallow latitudinal cline for percent striped melanisation as well as for frequency of body color alleles during the rainy season. The frequencies of body color alleles vary significantly across seasons in the northern populations i.e. the light allele occur abundantly (>0.94) during the rainy season while the frequency of the dark allele increases (0.22–0.35) during the dry season causing steeper clines during the dry season. By contrast, the low variations in abdominal stripes showed non-significant changes and the cline was similar across seasons. Furthermore, both types of melanisation patterns showed no plasticity with respect to temperature. The present study also investigated clines related to desiccation, heat and cold stress in D. ananassae females across seasons (rainy and dry) from nine latitudinal populations. The clines for stress related traits changes to steeper and non-linear during the dry season. Thus, latitudinal populations of D. ananassae differ in slope values of clines for stress related traits across seasons. This study reports seasonal changes in latitudinal clines of stress resistance traits as seen in a changing frequency of body color alleles of D. ananassae in northern locality, while in southern localities it remains constant. This is presumably the result of only minor seasonal changes in humidity and temperature in the South, whereas in the North seasonal climatic variability is much higher.