Municipal Solid Waste Recycling Issues

Municipal solid waste (MSW) recycling targets have been set nationally and in many states. Unfortunately, the definitions of recycling, rates of recycling, and the appropriate components of MSW vary. MSW recycling has been found to be costly for most municipalities compared to landfill disposal. MSW recycling policy should be determined by the cost to the community and to society more generally. In particular, recycling is a good policy only if environmental impacts and the resources used to collect, sort, and recycle a material are less than the environmental impacts and resources needed to provide equivalent virgin material plus the resources needed to dispose of the postconsumer material safely. From a review of the existing economic experience with recycling and an analysis of the environmental benefits (including estimation of external social costs), we find that, for most communities, curbside recycling is only justifiable for some postconsumer waste, such as aluminum and other metals. We argue that alternatives to curbside recycling collection should be explored, including product takeback for products with a toxic content (such as batteries) or product redesign to permit more effective product remanufacture.     

Chain length of the polylysine in receptor-targeted gene transfer complexes affects duration of reporter gene expression both in vitro and in vivo

Complexes composed of peptide ligand for the serpin enzyme complex receptor covalently coupled to poly-L-lysine condensed by charge interaction with plasmid DNA direct gene transfer into receptor bearing cells. We compared intensity and duration of reporter gene expression in vitro and in vivo from serpin-enzyme receptor-directed gene transfer complexes prepared with poly-L-lysine of different chain lengths. When substituted with linker and ligand to comparable extents, DNA complexes containing short chain poly-L-lysine were larger and gave higher peak expression but significantly shorter duration of expression than those containing long chain poly-L-lysine. Both peak expression and duration of expression exceeded that observed with Lipofectin. Neither naked DNA nor DNA complexed with unsubstituted polylysine was effective in gene transfer. For in vivo experiments, complexes containing optimal ligand and degree of substitution (based on in vitro data, peptide C105Y, 11 ligands/plasmid DNA molecule) were prepared with either short chain or long chain polylysine and a beta-galactosidase expression plasmid. Following injection into the tail veins of mice, longer chain complexes gave significantly higher expression of reporter gene in lung and spleen that lasted for a significantly longer period of time than the shorter chain complexes. The short chain poly-L-lysine-DNA complexes were larger in diameter, as assessed by electron microscopy or atomic force microscopy, and gave less protection against DNase digestion in vitro than longer chain complexes. Thus, for gene transfer complexes directed at the serpin enzyme complex receptor, longer chain poly-L-lysine gave a much longer duration of expression both in vitro and in vivo. We speculate that this may be due to protection against degradation afforded the plasmid DNA by the tighter compaction produced by long chain poly-L-lysine.     

Turkish aggregate electricity demand: An outlook to 2020

This paper investigates the relationship between Turkish aggregate electricity consumption, GDP and electricity prices in order to forecast future Turkish aggregate electricity demand. To achieve this, an aggregate electricity demand function for Turkey is estimated by applying the structural time series technique to annual data over the period 1960 to 2008. The results suggest that GDP, electricity prices and a UEDT (Underlying Energy Demand Trend) are all important drivers of Turkish electricity demand. The estimated income and price elasticities are found to be 0.17 and −0.11 respectively with the estimated UEDT found to be generally upward sloping (electricity using) but at a generally decreasing rate. Based on the estimated equation, and different forecast assumptions, it is predicted that Turkish aggregate electricity demand will be somewhere between 259 TWh and 368 TWh in 2020.     

Recombination in Tula hantavirus evolution: analysis of genetic lineages from Slovakia

To examine the evolution of Tula hantavirus (TUL), carried by the European common vole (Microtus arvalis and M. rossiaemeridionalis), we have analyzed genetic variants from Slovakia, the country where the virus is endemic. Phylogenetic analysis (PHYLIP) based on either partial (nucleotides [nt] 441 to 898) or complete N-protein-encoding sequences divided Slovakian TUL variants into two main lineages: (i) strains from eastern Slovakia, which clustered with Russian strains, and (ii) strains from western Slovakia situated closer to those from the Czech Republic. We found genetic diversity of 19% between the two groups and 4% within the western Slovakian TUL strains. Phylogenetic analysis of the 3' noncoding region (3'-NCR), however, placed the eastern Slovakian strains closer to those from western Slovakia and the Czech Republic, with a greater distance to the Russian strains, suggesting a recombinant nature of the S segment in the eastern Slovakian TUL lineage. A bootscan search of the S-segment sequences of TUL strains revealed at least two recombination points in the S sequences of eastern Slovakian TUL strains (nt 400 to 415 and around 1200) which agreed well with the pattern of amino acid substitutions in the N protein and deletions/insertions in the 3'-NCR of the S segment. These data suggest that homologous recombination events occurred in the evolution of hantaviruses.     

Subjective effects of peak clipping and compression limiting in normal and hearing-impaired children and adults

Despite many advances in hearing-aid signal processing, compression limiting and peak clipping are still used. To date, perceptual studies have been conducted only with adults. The current study was designed to investigate the clarity of peak-clipped and compressed speech for both adults and children. Subjects were 30 normal-hearing and 30 hearing-impaired individuals in three age ranges (7-9, 10-12, and 16-50 years). Stimuli were processed at 60, 70, 75, and 80 dB SPL using peak clipping and at 80 dB SPL using compression limiting. Paired-comparison measures were used to assess the clarity of sentences, and a signal-to-distortion ratio (SDR) based on a measure of coherence between input and output was computed for each condition. For the peak-clipping conditions, there was a decrease in perceived clarity as the input increased from 60 to 80 dB SPL. This perceptual continuum was most apparent for the normal-hearing adults. The normal-hearing 10-12 year olds and the hearing-impaired adults showed a similar, but less pronounced, pattern. In contrast, the remaining three subject groups showed minimal differences in perceived clarity across conditions. Surprisingly, only the two oldest normal-hearing groups showed a clear preference for compression limiting over peak clipping at the highest input level, and only their results were consistent with the pattern of coherence across stimuli. Judgments of clarity by the normal-hearing subjects correlated best with the SDR in the 500-2000-Hz range, while clarity judgments of the hearing-impaired subjects correlated best with the SDR below 1000 Hz.     

740 nm InP/GaInP quantum-dot laser with 190 A cm/sup -2/ room temperature threshold current density

InP quantum-dot lasers grown on GaAs substrates and emitting in the 730-740 nm band with threshold current density as low as 190 A cm/sup -2/ for a 2000 /spl mu/m-long device with uncoated facets are reported.     

Theory-based research for understanding the process of dynamic psychotherapy.

Research is reviewed on 6 theoretical propositions central to psychodynamic psychotherapy: (1) The establishment of an alliance is important to successful outcome; (2) the patient displays a central relationship theme (transference); (3) transference interpretations are helpful; (4) the therapist aims at accurate interpretations of the transference; (5) the patient gains understanding of self and the relationship pattern; and (6) the patient's improvement is reflected in changes in the relationship pattern, although the pattern is still evident. We suggest concepts that are in need of research development: internalization, resistance, working through, self-understanding and insight, and the therapist's adherence to recommended techniques. (PsycINFO Database Record (c) 2010 APA, all rights reserved)