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This paper develops a comparative framework for biotechnology policy analysis based on work by Paarlberg, Haga and Willard, and Isaac and applies this framework to help understand the evolution and differences in the regulatory re...
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This paper develops a comparative framework for biotechnology policy analysis based on work by Paarlberg, Haga and Willard, and Isaac and applies this framework to help understand the evolution and differences in the regulatory regimes related to agri-food genomic innovations found in six countries: Italy, Spain, Australia, New Zealand, Canada and the US. Applying this framework to the six cases shows that these governments have fostered different types of regulatory regimes over the last quarter century that are closely connected with the manner in which governments have pursued either promotional or precautionary orientations towards new technologies; and second whether regulatory policy-making has been driven by state or public actors and interests. The implications of these findings for the study of biotechnology, and especially genomics-related matters, regulation and policy-making are then discussed.
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In this article, we ask the question: how important is the participation element in the creation and reproduction of the Canadian biotechnology policy regime? We find that within the quasi-promotional regime currently in place in ...
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In this article, we ask the question: how important is the participation element in the creation and reproduction of the Canadian biotechnology policy regime? We find that within the quasi-promotional regime currently in place in Canada, participation plays an interesting role (close to Hirschman's 'voice' option), but not a core one in setting or modifying policy structure. It depends largely on the institutional setting within which the policy regime was originally constituted. We expect that in Canada, participation will make few inroads in changing the policy regime unless some core elements of the latter change.
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We report on improved stability of poly(3-hexylthiopene) (P3HT) and [6,6]-phenyl C_(61) butyric acid methyl ester bulk heterojunction solar cells using an indium tin oxide (ITO) anode and an indium metal cathode. Except for the IT...
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We report on improved stability of poly(3-hexylthiopene) (P3HT) and [6,6]-phenyl C_(61) butyric acid methyl ester bulk heterojunction solar cells using an indium tin oxide (ITO) anode and an indium metal cathode. Except for the ITO anode the devices are fabricated, stored, and tested entirely in air without encapsulation, exhibiting less than 10% loss in power conversion efficiency after 200 days. X-ray photoelectron spectroscopy shows that this improvement in ambient stability is correlated with the diffusion of indium from the cathode into the active polymer. The In oxidizes presumably resulting in a reduction in P3HT polymer chain degradation.
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House flies, Musca domestica, utilize ephemeral resources such as animal feces for oviposition and development of larval offspring, but they face competition with fungi that colonize the same resource. We predicted that house flie...
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House flies, Musca domestica, utilize ephemeral resources such as animal feces for oviposition and development of larval offspring, but they face competition with fungi that colonize the same resource. We predicted that house flies avoid oviposition on feces well-colonized with fungi, thereby reducing fungal competition for larval offspring. Working with fungal isolates from chicken feces, we have previously shown that prior establishment of Phoma spp., Fusarium spp., or Rhizopus spp. on feces significantly reduced oviposition by house flies. Here, we report that, in the headspace volatiles of these three fungal genera, five compounds (dimethyl trisulfide, an unknown, 2-phenylethanol, citronellal, norphytone) elicit responses from house fly antennae. In behavioral bioassays, dimethyl trisulfide and 2-phenylethanol significantly reduced oviposition by house flies. We conclude that fungus-derived volatiles serve as semiochemical cues that help house flies avoid resources colonized with fungal competitors for the development of larval offspring.
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Replication of surface nano-structures from a master stamp allows large-area volume production that is otherwise cost prohibitive through conventional direct-write methods, such as electron beam lithography and focused ion beam mi...
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Replication of surface nano-structures from a master stamp allows large-area volume production that is otherwise cost prohibitive through conventional direct-write methods, such as electron beam lithography and focused ion beam milling. However, the creation of a master stamp containing sophisticated patterns still requires significant time on such direct-write tools. We demonstrate a method for reducing this tool time by patterning smaller nano-structures, and then enlarging them to the desired size through isotropic etching. We can create circular structures of any arrangement and size, down to the patterning limits of the direct-write tools. Subsequent metal mask deposition, lift-off, and anisotropic etching transforms the circular patterns to out-of-plane pillar structures for the final stamp. A 1 cm~2 area filled with a pattern of 200 nm diameter nano-holes spaced 520 nm apart, requires only 21 h to complete using our process, compared to 75 h using conventional fabrication. We demonstrate the utility and practicality of the quartz stamps through polymer embossing and replication. Embossed polymer nano-hole arrays are coated with a Cr/Au (5/100 nm) film to create surface plasmon resonance structures. Extraordinary optical transmission spectra from the metallized arrays show the expected spectral features when compared to focused ion beam milled structures.
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Compact discs (CDs) can be used as rapid, low-cost, high-capacity screening platforms for running bioassays with no modification of the detection hardware (conventional standard optical drive). We describe herein a new protocol to...
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Compact discs (CDs) can be used as rapid, low-cost, high-capacity screening platforms for running bioassays with no modification of the detection hardware (conventional standard optical drive). We describe herein a new protocol to read and quantitate biotin-streptavidin binding assays with a standard optical drive by using a CD-data analysis software (IsoBuster), which identifies erroneous sectors by locating the exact error position bit-by-bit and allows various data formats to be used. The numbers of erroneous sectors increase as a function of the streptavidin concentration in the tested solutions. High spatial accuracy and detection sensitivity (0.3 μg/mL) were achieved.
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Anecdotal evidence suggests that cockroaches respond to electrical appliances or outlets. Our objectives were to determine the effect of field-inducing sources and field attributes on attraction of German cockroaches, Blattella ge...
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Anecdotal evidence suggests that cockroaches respond to electrical appliances or outlets. Our objectives were to determine the effect of field-inducing sources and field attributes on attraction of German cockroaches, Blattella germanica (L.) (Blattodea: Blattellidae), and to test those parameters found effective for attraction of B. germanica for attraction of other groups of insects. In two-choice, large-arena experiments, significantly more female, but not nymphal, B. germanica settled in or near electrified coils with static or fluctuating electromagnetic fields produced by low-level direct current (DC) or alternating current (AC) sources than in control coils without current. Electromagnetic fields with the magnetic, but not the electric, component of the field nulled still attracted B. germanica, suggesting that the electric component of the field may contribute to the attraction or arrestment response of B. germanica. DC-powered coils with static electromagnetic fields also attracted/arrested brown-banded cockroaches, Supella longipalpa (Fabricius) (Blattodea: Blattellidae), common silverfish, Lepisma saccharina (L.), firebrats, Thermobia domestica (Packard) (both Thysanura: Lepismatidae), and European earwigs, Forficula auricularia (L.) (Dermaptera: Forficulidae), but they repelled American cockroaches, Periplaneta americana (L.) (Blattodea: Blattidae). If proven in field experiments, electrified coils as trap baits may offer non-toxic alternatives to pesticides for selective insect control in urban environments.
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A method was developed for the quantification of matrine in human plasma using a liquid-liquid extraction procedure followed by gas-chromatography-mass spectrometry (GC/MS) analysis. Deuterated matrine, an internal standard of the...
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A method was developed for the quantification of matrine in human plasma using a liquid-liquid extraction procedure followed by gas-chromatography-mass spectrometry (GC/MS) analysis. Deuterated matrine, an internal standard of the analysis, was spiked into the plasma samples before extraction. Linear detection responses were obtained for matrine concentrations ranging from 10 to 500 ng/ml. The intra-day and inter-day precision ranged from 0.4 to 4.0% and 1.0-3.5%, respectively. The intra-day accuracy was between -7.3 and 4.5%. The limit of quantification for matrine was 23 ng/ml. The extraction efficiency averaged about 38%. The validated GC/MS method will be used to quantify matrine in human plasma samples collected in a clinical trial study.
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We report here the exploitation of the 150 cavity in the active site of influenza A viral neuraminidases for the design of novel C-6 triazole-containing Tamiflu derivatives. A general and convenient synthetic route was developed b...
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We report here the exploitation of the 150 cavity in the active site of influenza A viral neuraminidases for the design of novel C-6 triazole-containing Tamiflu derivatives. A general and convenient synthetic route was developed by utilizing a highly substituted cyclic Baylis-Hillman acetate as an active precursor for azide substitution via suprafacial allylic azide [3,3]-sigmatropic rearrangement. Virus replication inhibitory assays in vitro of these triazole derivatives containing either an amino or guanidino function indicated that the guanidinium compound showed the higher efficacy against a strain with N2 subtype at a concentration of 2 × 10~(-5) M but did not inhibit replication of a strain with N1 subtype even at a concentration of 10 ~(-4) M. In order to probe the nature of the enzyme-inhibitor interactions, molecular dynamics simulations were performed on complexes of these compounds with different neuraminidase enzymes. The results indicated that the candidate inhibitors occupy both the 150 cavity and catalytic site but with alternating occupancy.
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Sexual isolation can evolve due to natural selection against hybrids (reinforcement). However, many different forms of hybrid dysfunction, and selective processes that do not involve hybrids, can contribute to the evolution of sex...
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Sexual isolation can evolve due to natural selection against hybrids (reinforcement). However, many different forms of hybrid dysfunction, and selective processes that do not involve hybrids, can contribute to the evolution of sexual isolation. Here we review how different selective processes affect the evolution of sexual isolation, describe approaches for distinguishing among them, and assess how they contribute to variation in sexual isolation among populations of Timema cristinae stick-insects. Pairs of allopatric populations of T. cristinae living on different host-plant species exhibit greater sexual isolation than those on the same host, indicating that some sexual isolation has evolved due to host adaptation. Sexual isolation is strongest in regions where populations on different hosts are in geographic contact, a pattern of reproductive character displacement that is indicative of reinforcement. Ecological costs to hybridization do occur but traits under ecological selection (predation) do not co-vary strongly with the probability of between-population mating such that selection on ecological traits is not predicted to produce a strong correlated evolutionary response in mate preference. Moreover, F1 hybrid egg inviability is lacking and the factors contributing to reproductive character displacement require further study. Finally, we show that sexual isolation involves, at least in part, olfactory communication. Our results illustrate how understanding of the evolution of sexual isolation can be enhanced by isolating the roles of diverse ecological and evolutionary processes.
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