Use of Marine Waste Extract as a Nitrogen Source for Biological Sulfate Reduction: Development of a Suitable Alternative

Marine wastes extract (MWE), prepared from marine organic wastes, was used to develop an alternative nitrogen source for sulfate-reducing bacteria (SRB) in environments like acid mine drainage that are acidic in nature and contain high levels of sulfate and dissolved metals. The MWE contains 13.95 g L^?1 of nitrogen, and other micronutrients like K, Na, P, S, Ca, Fe, Mg, Mn, Zn, Co, Cu and Ni, and has a C/N ratio of 0.107. A modified SRB medium (MSRB) was developed by replacing the commercial nitrogen source of standard SRB growth medium with MWE. MSRB was compared with modified Postgate B, Postgate B, and Widdel and Pfennig media, which contained bactopeptone and NH₄Cl, as nitrogen sources. Results showed that the growth media could support a total microbial population of 2.8 × 10¹²–6.2 × 10¹² cells mL^?1 with 96, 80, 92.5, and 65 % SRB in MSRB, Postgate B, modified Postgate B, and Widdel and Pfennig media, respectively. The sulfate reduction efficiency was 97, 87, 72, and 68 % at reduction rates of 12.41, 11.10, 4.35, and 8.8 mg L^?1 h^?1, respectively, for the same media. We conclude that MWE could be a cost-effective substitute for commercially available nitrogen sources for SRB for large-scale treatment of sulfate-rich wastewater.     

Human capital and per capita product: A comparison of US states

This article analyzes the extent to which human capital differences can explain the differences in gross state product (GSP) per capita levels between the richer and poorer states of the US. It uses 1990 Census and Bureau of Economic Analysis data on educational attainment, wage levels of different segments of the labor force, and GSP to compare New York – our representative rich state – with the poorest third of the states. The findings indicate that human capital differences explain at least 49% of the observed difference in GSP per capita between New York and each of the poor states. Received: 19 May 1999 / Accepted: 19 September 1999     

Structure-function analysis of a conserved aromatic cluster in the N- terminal domain of human epidermal growth factor

The importance of a cluster of conserved aromatic residues of human epidermal growth factor (hEGF) to the receptor binding epitope is suggested by the interaction of His10 and Tyr13 of the A-loop with Tyr22 and Tyr29 of the N-terminal beta-sheet to form a hydrophobic surface on the hEGF protein. Indeed, Tyr13 has previously been shown to contribute a hydrophobic determinant to receptor binding. The roles of His10, Tyr22 and Tyr29 were investigated by structure-function analysis of hEGF mutant analogues containing individual replacements of each residue. Substitutions with aromatic residues or a leucine at position 10 retained receptor affinities and agonist activities similar to wild- type indicating that an aromatic residue is not essential. Variants with polar, charged or aliphatic substitutions altered in size and/or hydrophobicity exhibited reduced binding and agonist activities. 1- Dimensional 1H NMR spectra of high, moderate and low-affinity analogues at position 10 suggested only minor alterations in hEGF native structure. In contrast, a variety of replacements were tolerated at position 22 or 29 indicating that neither aromaticity nor hydrophobicity of Tyr22 and Tyr29 is required for receptor binding. CD spectra of mutant analogues at position 22 or 29 indicated a correlation between loss of receptor affinity and alterations in hEGF structure. The results indicate that similar to Tyr13, His10 of hEGF contributes hydrophobicity to the receptor binding epitope, whereas Tyr22 and Tyr29 do not appear to be directly involved in receptor interactions. The latter conclusion, together with previous studies, suggests that hydrophobic residues on only one face of the N-terminal beta-sheet of hEGF are important in receptor recognition.      

Highly hydrophobic hierarchical nanomicro roughness polymer surface created by stamping and laser micromachining

This article describes the design and fabrication of hierarchical nanomicrostructured polymer surfaces with high hydrophobicity. The nanoscale roughness is achieved by stamping a ZnO nanowire film into PDMS. Subsequently, microstructures with different periodicities are created in the stamped PDMS sample by direct laser writing using femtosecond pulses. With this approach, we were able to produce hierarchical surface morphologies, composed of nano and microscale structures that exhibit water contact angles larger than 160°. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42082.     

Modeling of bubble‐size distribution in water and freon co‐blown free rise polyurethane foams

A model has been developed to simulate the foam characteristics obtained, when chemical (water) and physical (Freon) blowing agents are used together for the formation of polyurethane foams. The model considers the rate of reaction, the consequent rise in temperature of the reaction mixture, nucleation of bubbles, and mass transfer of CO₂ and Freon to them till the time of gelation. The model is able to explain the experimental results available in literature. It further predicts that the nucleation period gets reduced with increase in water (at constant Freon content), whereas with increase in Freon (at constant water) concentration nucleation period decreases marginally leading to narrower bubble‐size distribution. By the use of uniform sized nuclei added initially, the model predicts that the bubble‐size distribution can be made independent of the rate of homogeneous nucleation and can, thus, offer an extra parameter for its control. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40745.     

Methotrexate treatment for sarcoid-associated panuveitis

OBJECTIVE: To determine the safety and efficacy of low-dose methotrexate (MTX) for sarcoid-associated panuveitis. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Twenty eyes from 11 patients were analyzed. Eight patients had sarcoidosis. Three patients were clinically suspected of sarcoidosis despite negative laboratory testing. All charts of patients with sarcoidosis and idiopathic uveitis seen by the Duke Uveitis Service from 1989 to 1997 were retrospectively reviewed. Those with sarcoid-associated or sarcoid-suspected panuveitis treated with MTX with a minimum of 6 months of follow-up were studied. INTERVENTION: Low-dose MTX was administered to patients weekly and patients were followed with serial ophthalmologic and medical examinations. MAIN OUTCOME MEASURES: Visual acuity, oral and topical corticosteroid requirements, anterior chamber inflammation, and ability to undergo successful cataract extraction were used to measure the efficacy of MTX therapy. RESULTS: After MTX treatment was initiated, 90% of eyes had preserved or improved visual acuity. Mean initial Snellen visual acuity was 20/62 and mean final acuity was 20/40 (P = 0.044). Of those patients initially requiring oral corticosteroids, the dosage was decreased in 100%, and they were completely discontinued in 86%. The mean initial oral corticosteroid dose was 26.6 mg and the mean final dose was 1.5 mg (P = 0.012). Topical corticosteroids were decreased in 63% of eyes. The mean initial use was once every 1.6 hours, and the mean final use was once every 3.9 hours (P = 0.001). Ninety-five percent of eyes had stabilized or decreased inflammation. The mean initial inflammation score was 1.2, and the mean final score was 0.5 (P = 0.007). Five of six eyes previously unable to have cataract extraction because of uncontrolled inflammation became quiet on MTX and underwent surgery. One hundred percent of these eyes had improved vision after surgery. Side effects were mild and transient or reversible. CONCLUSION: Low-dose MTX is an effective and safe adjunct to treat chronic sarcoid-associated panuveitis.     

Electrochemotherapy: transition from laboratory to the clinic

Although electroporation in the past has mainly been used as a research tool, recent work has demonstrated its potential for clinical applications. Some of the areas explored include electrochemotherapy (ECT), which utilizes electroporation as a means for delivering chemotherapeutic agents directly into tumor cells, encapsulation of drugs or genes into cells for their use as carrier systems, transdermal delivery of drugs or genes, gene therapy, and delivery of drugs or genes with an electroporation catheter. This article discusses the principles of ECT as a method of treating cancer, the requirements and development of electronic and electromechanical hardware for ECT, and it presents data for both in-vivo animal studies and clinical applications, especially for subcutaneous tumors. It is concluded that ECT has shown promise in treating a variety of cancers in humans. The basic principles are reasonably well understood. A good start has been made in the development of the necessary hardware to generate and apply the needed electric fields. As the human genome project progresses in identifying gene-based diseases and their possible cures, the same hardware system used for ECT can also be used for electrogene therapy. As ECT-based therapy becomes more widely recognized, it will offer an additional treatment modality and increased hope for cancer patients.     

The influence of land-use change and landscape dynamics on the climate system: relevance to climate-change policy beyond the radiative effect of greenhouse gases

Our paper documents that land-use change impacts regional and global climate through the surface-energy budget, as well as through the carbon cycle. The surface-energy budget effects may be more important than the carbon-cycle effects. However, land-use impacts on climate cannot be adequately quantified with the usual metric of 'global warming potential'. A new metric is needed to quantify the human disturbance of the Earth's surface-energy budget. This 'regional climate change potential' could offer a new metric for developing a more inclusive climate protocol. This concept would also implicitly provide a mechanism to monitor potential local-scale environmental changes that could influence biodiversity.