Leaching characteristics of the fine fraction from an excavated landfill: physico-chemical characterization

Leaching of fine fraction (<10 mm) obtained from landfill mining activities in an Estonian landfill was done. On-site excavation was carried out in four test pits (TP1, TP2, TP3, TP4) that were further divided in four layers (L1, L2, L3, L4). Total chemical oxygen demand (CODt), dissolved chemical oxygen demand (CODd), total organic carbon (TOC), dissolved organic carbon (DOC) and metals (Zn, Cu, Pb and Cd) were analyzed. The results showed that approximately 70 % of CODt were in particulate/colloidal state. The TOC released ranged between 2326 and 3530-mg/kg dry matter for test pits suggesting spatial differences in the studied landfill. DOC ranged between 365–874 and 317–940 mg/kg for different test pits and sampling layers, respectively. Low average leaching rates of metals were observed (0.2–1.5 %). Pb had a significantly higher average leaching rate (1.0 %) compared to Zn (0.70 %) and Cu (0.35 %). The potential use of CODt as a surrogate indicator of TOC, DOC and Zn on the basis of high correlation coefficients was observed. To conclude, the implementation of adequate strategies to manage fine-grained fractions obtained from excavated waste relies on physico-chemical characterization of both the fine fractions itself and the leachate generated during storage and use. © 2015 Springer Japa

Reduction of spurious velocity in finite difference lattice Boltzmann models for liquid - vapor systems

The origin of the spurious interface velocity in finite difference lattice Boltzmann models for liquid - vapor systems is related to the first order upwind scheme used to compute the space derivatives in the evolution equations. A correction force term is introduced to eliminate the spurious velocity. The correction term helps to recover sharp interfaces and sets the phase diagram close to the one derived using the Maxwell construction.Comment: 22 pages, 10 figures (submitted to International Journal of Modern Physics C- Physics and Computers

Gingival Displacements Options in Prosthodontics: A Critical Review on Recent Advances

A plethora of innovations have taken place in impression-making for fixed prosthesis, all with a singular objective to record the finish margins of tooth preparation and the gingival tissues. The gingival displacement temporarily displaces the tissues laterally to adequately record the sub-gingival margins. The purpose of this review is to make an appraisal of the latest advancements in the field of tissue-displacement and analyze their merits and demerits. A conscientious dentist is one with lucid comprehension of concepts, a keen discerning eye on recent developments, well-informed choice of treatment plan, and impeccable execution of the chosen plan

Scanning and Transmission Electron Microscopic Studies on the Oviducts of Pekin Ducks Fed Methyl Mercury Containing Diets

This study was undertaken to examine the effects of varying levels of methyl mercury (MeHg) on the ultrastructure of the surface epithelium of the oviduct of ducks. Accordingly, Pekin ducks were maintained on feed containing varying doses of (0.0; 0.5; 5.0; 15.0 ppm) of MeHg (Group I - control to IV) for 12 weeks and sacrificed. Tissue from the magnum and the shell gland regions of the oviduct was processed for scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the primary and secondary folds of these regions of the oviducts of the control and 0.5 ppm treatment group were densely populated with ciliated cells and that the cilia tend to cover the apical surfaces of the non-ciliated secretory cells. This unchanged ultrastructural morphology of the surface epithelium of 0.5 ppm treatment group was verified with TEM. The ciliated and nonciliated cells in surface epithelium appeared to be equal in frequency. The nuclei of ciliated cells were superficial in location compared to nonciliated secretory cells which had nuclei in the basal part of the cytoplasm. In the oviducal tissues from ducks fed 5.0 ppm MeHg isolated areas of ciliary loss, but minimal disruption of the apical plasma membrane were observed by SEM. In a few birds plasma membrane lesions, condensation of nuclear chromatin and very dilated rough endoplasmic reticulum were seen with TEM. In the oviducal tissues from ducks fed 15.0 ppm MeHg it could be seen that ciliary loss was much more extensive than hitherto observed, and disruption of the apex of cells could be seen. TEM showed degeneration of cytoplasmic organelles, more or less severely damaged ciliated cells, loss of ciliary extensions and formation of compound cilia. These observations indicate that methyl mercury at 5.0 and 15.0 ppm dose levels causes toxic injury to oviducal surface epithelium of Pekin duck that may cause reduced reproductive capability

Current Status of Radioisotope Applications in Defence

Reviews the current status of radioisotope applications in Defence- R&amp;D Establishments, Defence Inspectorates, Ordnance Factories, Public Sector Undertakings under the Defence Ministry, Army, Navy and Air Force Establishments and Military Hospitals. It also lists the users of film badge service in Defence. Training programmes in radioisotope applications in Defence conducted by DRDO organisations have also been highlighted

Structural aberrations in fluorosed human teeth: Biochemical and scanning electron microscopic studies

The present investigation was carried out to provide biochemical and ultrastructural evidences on the aberrations that appear in teeth in human Dental Fluorosis (DF), a condition caused by excess intake of fluoride. Human fluorosed teeth were obtained from the OPD of Madras Dental College, Chennai. Normal tooth samples were also collected from patients who opted for denture. The samples were investigated for fluoride and calcium contents, besides the tooth surfaces were examined under scanning electron microscope to assess the morphological aberrations. An increase in fluoride content and decrease in calcium content in fluorosed human teeth were observed when compared to the control. The scanning electron micrographs of the enamel surface of fluorosed human teeth show pitted, uneven and rough surfaces. Cracks and fissures were also observed on the enamel surface of fluorosed teeth. The present study provides evidence to suggest that pitting, perforation and structural alterations in DF are the result of impaired enamel mineralization

An sRNA Screen for Reversal of Quinolone Resistance in Escherichia coli

In light of the rising prevalence of antimicrobial resistance (AMR) and the slow pace of new antimicrobial development, there has been increasing interest in the development of adjuvants that improve or restore the effectiveness of existing drugs. Here, we use a novel small RNA (sRNA) screening approach to identify genes whose knockdown increases ciprofloxacin (CIP) sensitivity in a resistant strain of Escherichia coli 5000 sRNA constructs were initially screened on a gyrA S83L background, ultimately leading to 30 validated genes whose disruption reduces CIP resistance. This set includes genes involved in DNA replication, repair, recombination, efflux, and other regulatory systems. Our findings increase understanding of the functional interactions of DNA Gyrase, and may aid in the development of new therapeutic approaches for combating AMR

Position-dependent mass models and their nonlinear characterization

We consider the specific models of Zhu-Kroemer and BenDaniel-Duke in a sech$^{2}$-mass background and point out interesting correspondences with the stationary 1-soliton and 2-soliton solutions of the KdV equation in a supersymmetric framework.Comment: 8 Pages, Latex version, Two new references are added, To appear in J.Phys.A (Fast Track Communication

CRISPR for accelerating genetic gains in under utilized crops of the drylands: Progress and prospects

Technologies and innovations are critical for addressing the future food system needs where genetic resources are an essential component of the change process. Advanced breeding tools like “genome editing” are vital for modernizing crop breeding to provide game-changing solutions to some of the “must needed” traits in agriculture. CRISPR/Cas-based tools have been rapidly repurposed for editing applications based on their improved efficiency, specificity and reduced off-target effects. Additionally, precise gene-editing tools such as base editing, prime editing, and multiplexing provide precision in stacking of multiple traits in an elite variety, and facilitating specific and targeted crop improvement. This has helped in advancing research and delivery of products in a short time span, thereby enhancing the rate of genetic gains. A special focus has been on food security in the drylands through crops including millets, teff, fonio, quinoa, Bambara groundnut, pigeonpea and cassava. While these crops contribute significantly to the agricultural economy and resilience of the dryland, improvement of several traits including increased stress tolerance, nutritional value, and yields are urgently required. Although CRISPR has potential to deliver disruptive innovations, prioritization of traits should consider breeding product profiles and market segments for designing and accelerating delivery of locally adapted and preferred crop varieties for the drylands. In this context, the scope of regulatory environment has been stated, implying the dire impacts of unreasonable scrutiny of genome-edited plants on the evolution and progress of much-needed technological advances