Dynamic temperature dependence patterns in future energy demand models in the context of climate change

Energy demand depends on outdoor temperature in a ‘u’ shaped fashion. Various studies have used this temperature dependence to investigate the effects of climate change on energy demand. Such studies contain implicit or explicit assumptions to describe expected socio-economic changes that may affect future energy demand.This paper critically analyzes these implicit or explicit assumptions and their possible effect on the studies' outcomes. First we analyze the interaction between the socio-economic structure and the temperature dependence pattern (TDP) of energy demand. We find that socio-economic changes may alter the TDP in various ways. Next we investigate how current studies manage these dynamics in socio-economic structure. We find that many studies systematically misrepresent the possible effect of socio-economic changes on the TDP of energy demand. Finally, we assess the consequences of these misrepresentations in an energy demand model based on temperature dependence and climate scenarios. Our model results indicate that expected socio-economic dynamics generally lead to an underestimation of future energy demand in models that misrepresent such dynamics. We conclude that future energy demand models should improve the incorporation of socio-economic dynamics. We propose dynamically modeling several key parameters and using direct meteorological data instead of degree days.     

Practical aspects of the detection of lactic bacteria in beer

The conventional method used for the detection of microbiological contaminations in beer requires at least 4 days but often extends to 7 days for the detection of Pediococcus. In order to reduce the detection time for lactic bacteria, and especially Pediococcus, we studied the influence of various cultural factors on the rate of growth of 20 strains of Pedioccocus and 16 strains of Lactobacillus. Simple modifications of the MRS medium (pH 5·5 adjusted with HCl, 0·05 at ethanol) have allowed us to reduce by as much as two days the detection of lactic bacteria as compared with conventional method used in our laboratory.     

THE DETERMINATION OF IRON COPPER AND CALCIUM IN BEER

The atomic absorption methods for iron, copper and calcium in beer, published by the American Society of Brewing Chemists, are recommended.     

A rapid and velocity-independent damage localization approach for ultrasonic structural health monitoring

This paper presents a novel damage localization approach for active ultrasonic structural health monitoring. The formalism considers triplets of two actuators and one sensor in a spatially distributed transducer network. Depending on time-of-flight measurements that are automatically conducted on differential signals, the defect position in isotropic and quasi-isotropic plates is located very rapidly without the wave velocity information. This is particularly beneficial when the wave speed cannot be obtained because of an unknown stacking sequence of the laminate. Results are shown for different point-like defects on isotropic and quasi-isotropic structures for which the processing time is less than 1 s on a standard computer.     

A field study of the microbiological quality of fresh produce of domestic and Mexican origin

Produce is responsible for an increasingly larger proportion of foodborne disease outbreaks. In particular, the globalization of the food supply may introduce new food safety risks and allow widespread distribution of contaminated food, particularly produce. The objectives of this study were to: (i) compare the overall quality of domestic and Mexican produce throughout the packing process; (ii) examine changes in microbiological quality of both domestic and Mexican produce at each stage of production and processing; and (iii) evaluate the prevalence of select pathogens on fresh produce, including leafy green, herbs, melons, and vegetables. Furthermore, we also sought to characterize the antibiotic resistance profiles of Enterococcus faecium and Enterococcus faecalis strains isolated from fresh produce. A total of 466 produce and matching environmental swab samples was collected from various locations in packing sheds in the southern US from November 2002 through December 2003. These samples were assayed by enumerative tests for total aerobic bacteria (APC), total coliforms, total Enterococcus, and E. coli. Produce samples were also analyzed for the presence of Salmonella, Listeria monocytogenes, Shigella, and E. coli O157:H7. A total of 112 E. faecium and E. faecalis isolates were further screened for antibiotic resistance using a panel of seventeen antibiotics. Overall, the microbiological quality of fresh produce ranged from 4.0 to 7.9 log(10) CFU/g (APC); less than 1.0 log(10) to 4.5 log(10) CFU/g (coliforms); less than 1.0 log(10) to 4.0 log(10) CFU/g (E. coli); and less than 1.0 log(10) to 5.4 log(10) CFU/g (Enterococcus). No Salmonella, Shigella, or E. coli O157:H7 were detected from the 466 25-g produce samples tested. However, three domestic cabbage samples were found to be positive for L. monocytogenes. Of the Enterococcus isolates, E. faecium had a higher degree of resistance to antibiotics in general, while Enterococcus spp. isolated from Mexican produce had a higher degree of antibiotic resistance when compared to strains isolated from produce samples of domestic origin. Despite increased attention to the role of imported produce in foodborne disease, this study does not support the assumption that domestic produce is of higher microbial quality than Mexican produce.     

Identification of the tissue inhibitor of metalloproteinases-2 (TIMP-2) binding site on the hemopexin carboxyl domain of human gelatinase A by site-directed mutagenesis. The hierarchical role in binding TIMP-2 of the unique cationic clusters of hemopexin modules III and IV

Cell surface activation of progelatinase A occurs in a quaternary complex with the tissue inhibitor of metalloproteinases-2 (TIMP-2) and two membrane-type matrix metalloproteinases. We have mutated the unique cationic clusters found in hemopexin modules III and IV of the carboxyl domain (C domain) of human gelatinase A to determine their role in binding TIMP-2. Twelve single, double, and triple site-directed mutations were produced that exhibited different TIMP-2 binding properties. Notably, single alanine substitutions at Lys547 and Lys617 reduced TIMP-2 binding by an order of magnitude from that of the recombinant wild-type C domain. Mutations that completely disrupted the C domain.TIMP-2 interaction were K558A/R561A, K610T/K617A, and K566A/K568A/K617A. A triple mutation, K566A/K568A/K575A, having TIMP-2 binding indistinguishable from the wild-type C domain (Kd 3.0 x 10(-8) M), showed that simple reduction of net positive charge does not reduce TIMP-2 affinity. Because the double mutation K566A/K568A also did not alter TIMP-2 binding, these data do not confirm previously reported chimera studies that indicated the importance of the triple lysine cluster at positions 566/567/568 in TIMP-2 binding. Nonetheless, a subtle role in TIMP-2 interaction for the 566/567/568-lysine triad is indicated from the enhanced reduction in TIMP-2 binding that occurs when mutations here were combined with K617A. Thus, these analyses indicate that the TIMP-2 binding surface lies at the junction of hemopexin modules III and IV on the peripheral rim of the gelatinase A C domain. This location implies that considerable molecular movement of the TIMP-2. C domain complex would be needed for the bound TIMP-2 to inhibit in cis the gelatinase A active site.     

Path planning for deformable linear objects

We present a new approach to path planning for deformable linear (one-dimensional) objects such as flexible wires. We introduce a method for efficiently computing stable configurations of a wire subject to manipulation constraints. These configurations correspond to minimal-energy curves. By restricting the planner to minimal-energy curves, the execution of a path becomes easier. Our curve representation is adaptive in the sense that the number of parameters automatically varies with the complexity of the underlying curve. We introduce a planner that computes paths from one minimal-energy curve to another such that all intermediate curves are also minimal-energy curves. This planner can be used as a powerful local planner in a sampling-based roadmap method. This makes it possible to compute a roadmap of the entire "shape space," which is not possible with previous approaches. Using a simplified model for obstacles, we can find minimal-energy curves of fixed length that pass through specified tangents at given control points. Our work has applications in cable routing, and motion planning for surgical suturing and snake-like robots.     

Damage Detection and Localization in Metallic Structures Based on <Emphasis Type="Italic">Jointed Electromagnetic Waveguides</Emphasis>: A Proof-of-Principle Study

This paper presents a novel approach for the detection of surface damage in metallic structures, where the electromagnetic waveguide forms a union with the structure to be inspected. The sensing concept in such jointed electromagnetic waveguides will be described here and measurement results will be presented using a hollow metallic waveguide on an aluminium sample. The experimental proof of principle is performed in the frequency band from 20 to 40 GHz using a network analyzer. It is possible to (i) detect holes as small as 1 mm, (ii) discriminate between different hole sizes, and, (iii) localize the axial position of the defect in the waveguide. This approach has great potential to be used for structural health monitoring of complex technical structures and components.