687 research outputs found
Microbial production of polyhydroxy alkanotes (PHA) from Alcaligens spp. and Pseudomonas oleovorans using different carbon sources
Plastics have resistance to biological breakdown that result in its accumulation in the environment. This emphasizes the need to search for biodegradable polymer, which is easily disposable and degradable. Bacteria synthesize and accumulate polyhydroxy alkanote (PHA) as carbon source under limiting conditions of nutrients. The effect of different nutrient conditions on production of PHA by Alcaligens eutrophus, Alcaligens latus and Pseudomonas oleovorans was screened and characterized in this study. The influence of different carbon sources on PHA production showed that, medium with glucose as carbon source produced the maximum PHA content of 4.14 g/l from A. eutrophus. P.oleovorans produced 2.06 g/l from n-octane as carbon source. The functional groups of the extracted PHA granules were identified as C=O group by fourier transform infrared (FTIR) spectroscopy analysis.Biodegrability studies showed that, the PHA produced is degradable by a number of soil microbes making it an ideal environmentally friendly material for regular human use
Induced maturation of penaeid prawns for hatchery operations
For successful hatchery production of penaeid prawn seed a steady supply of spawners of desired species of prawns is a necessary prerequisite. As the collection of spawners from the sea is a costly and uncertain operation, efforts have been made to induce the captive broodstock to mature under controlled conditions
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Modeling Virus Transport and Removal during Storage and Recovery in Heterogeneous Aquifers
A quantitative understanding of virus removal during aquifer storage and recovery (ASR) in physically and geochemically heterogeneous aquifers is needed to accurately assess human health risks from viral infections. A two-dimensional axisymmetric numerical model incorporating processes of virus attachment, detachment, and inactivation in aqueous and solid phases was developed to systematically evaluate the virus removal performance of ASR schemes. Physical heterogeneity was considered as either layered or randomly distributed hydraulic conductivities (with selected variance and horizontal correlation length). Geochemical heterogeneity in the aquifer was accounted for using Colloid Filtration Theory to predict the spatial distribution of attachment rate coefficient. Simulation results demonstrate that the combined effects of aquifer physical heterogeneity and spatial variability of attachment rate resulted in higher virus concentrations in the recovered water at the ASR well (i.e. reduced virus removal). While the sticking efficiency of viruses to aquifer sediments was found to significantly influence virus concentration in the recovered water, the solid phase inactivation under realistic field conditions combined with the duration of storage phase had a predominant influence on the overall virus removal. The relative importance of physical heterogeneity increased under physicochemical conditions that reduced virus removal (e.g. lower value of sticking efficiency or solid phase inactivation rate). This study provides valuable insight on site selection of ASR projects and an approach to optimize ASR operational parameters (e.g. storage time) for virus removal and to minimize costs associated with post-recovery treatment
Stars as Catalysts: An Event-Study Analysis of the Impact of Star-Scientist Recruitment on Local Research Performance in a Small Open Economy
There is increasing interest among policymakers in small open economies in the use of star-scientist recruitment policies to catalyse the development of local clusters in targeted research areas. We use Scopus to assemble a dataset on over 1.4 million publications and subsequent citations for Denmark, Ireland and New Zealand from 1990 to 2017. An event-study model is used to estimate the dynamic effects of a star arrival on quality-adjusted research output at both the department and matched individual incumbent levels. Star arrivals are associated with statistically significant increases in department output (excluding the output of the star) of between 12% and 25% after 4 years. At the incumbent level, star arrivals lead to an approximately 5% increase in individual output, with substantially larger increases for incumbents who co-author with the star
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Lymphoid priming in human bone marrow begins before expression of CD10 with upregulation of L-selectin.
Expression of the cell-surface antigen CD10 has long been used to define the lymphoid commitment of human cells. Here we report a unique lymphoid-primed population in human bone marrow that was generated from hematopoietic stem cells (HSCs) before onset of the expression of CD10 and commitment to the B cell lineage. We identified this subset by high expression of the homing molecule L-selectin (CD62L). CD10(-)CD62L(hi) progenitors had full lymphoid and monocytic potential but lacked erythroid potential. Gene-expression profiling placed the CD10(-)CD62L(hi) population at an intermediate stage of differentiation between HSCs and lineage-negative (Lin(-)) CD34(+)CD10(+) progenitors. CD62L was expressed on immature thymocytes, and its ligands were expressed at the cortico-medullary junction of the thymus, which suggested a possible role for this molecule in homing to the thymus. Our studies identify the earliest stage of lymphoid priming in human bone marrow
Use of gemcitabine and ginger extract infusion may improve the efficiency of cervical cancer treatment
Chemotherapy uses drugs to kill cancer cells, either by preventing them from multiplying or by causing the cells to self-destruct. However, in most cases, high systemic toxicity and drug resistance limit the successful outcomes of treatment regimes. Prevention of cancer through dietary intervention recently has received an increasing interest and dietary polyphenols have become not only important potential chemopreventive, but also therapeutic, natural agents. Combination of effective chemopreventive agent (such as ginger) with chemotherapeutic agents may enhance efficacy while reducing toxicity to normal tissues, resulting in better survival. In this study, we observed that treatment of human cervical carcinoma cell line, HeLa with ethanolic ginger extract in combination with gemcitabine resulted in significant dose-dependent decrease in cell viability. It is noteworthy that use of ginger extract increased the efficacy of gemcitabine and importantly, it was found to be minimally toxic to normal cells. Together, these results suggest a novel mechanism may be involved in the synergistic effect of this combination. Thus, this combination may be an effective modality management in the treatment of cervical cancer
The heterogeneity of MNC' subsidiaries and technology spillovers: explaining positive and negative effects in emerging economies
Comparative assessment of the impact of motorisation on the artisanal fisheries at Vizhinajam
The fishery statistics collected from Vizhinjam
fish landing centre for seven years from 1986 to
1992 was utilised as the data for the motorisation period. The fishery data during the pre-motorisation
period is taken from Luther et cd. (1982) for
presenting the comparative assessment of the
impact of motorisation. An Increase in the total fish catch as well as in the catch per unit effort is evident during themotorisation period. The fast accessibility to the distant fishing grounds by the motorlsed crafts,
the increased number of fishing hands employed
in the motorlsed units and the avEiilability of more
time for actual fishing due to the time saved for
rowing seem to be the major reasons for the higher
catch and catch rate in the motorlsed units
Synchrotron X-ray Studies of the Structural and Functional Hierarchies in Mineralised Human Dental Enamel:A State-of-the-Art Review
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