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51.
Creating informed public opinion: citizen deliberation about nanotechnologies for human enhancements
Michael D. Cobb 《Journal of nanoparticle research》2011,13(4):1533-1548
Many people believe that ordinary citizens should influence scientific and technological developments, but the American public
is routinely uninformed about these issues. As a solution, some scholars advocate creating informed public opinions by encouraging
citizens to deliberate about the issues. Although this idea is currently widely applauded in the science and technology literature,
deliberative outcomes are infrequently measured and the practice of deliberation is routinely criticized in other disciplines.
This research contributes to our understanding of the effectiveness of citizen deliberation as a method for increasing public
engagement with science. I report data measuring results of deliberation in a national citizens’ technology forum (NCTF)
about nanotechnologies for human enhancement. The NCTF was a month-long process involving six groups of 9–15 ordinary citizens
who deliberated in different locations across the United States with the goal of reaching consensus about policy recommendations
within their groups. I find that structured deliberation generated informed opinions, sometimes meaningful shifts in preferences,
and increased trust and internal efficacy among the participants. Nevertheless, the NCTF has important shortcomings, and it
is not obvious that consensus conferences should be preferred over other mechanisms for creating informed opinions. Future
research is needed to corroborate the findings of this study and to systematically compare outcomes of structured citizen
deliberation to other less resource intensive forms of engagement. 相似文献
52.
J.J. Aubert G. Bassompierre K.H. Becks C. Best E. B?hm X. de Bouard F.W. Brasse C. Broll S. Brown J. Carr R.W. Clifft J.H. Cobb G. Coignet F. Combley J.M. Crespo G. DAgostini P.F. Dalpiaz S.J. Wimpenny 《Physics letters. [Part B]》1981,106(5):419-422
Two trimuon events of the type μ+N→μ+μ+μ+X and one μ+N→μ+μ?μ?X have been observed in 250 GeV μ+ -iron interactions. The expected rate from the decay of hadrons (charm, π, K) is about one event. Other processes that may contribute are both beauty production and charm production with mixing. The data give upper limits of 12×10?36 cm2 for the cross section of beauty pair production by muons, and 20% for transitions due to mixing, both at 90% confidence level. 相似文献
53.
Gaussian orbital calculation of the ESR coupling constants in the PF2 radical are presented, in excellent agreement with experiment. 相似文献
54.
Li L Kresh JA Karabacak NM Cobb JS Agar JN Hong P 《Journal of the American Society for Mass Spectrometry》2008,19(12):1867-1874
This article presents a memory efficient algorithm for accurately calculating the isotopic fine structures of molecules. Treating individual isotopic species of a molecule as different mass states, we introduce the concept of transitions between mass states and represent all mass states of the molecule in a hierarchical structure. We show that there exists a simple relationship between two different mass states at two different levels of the hierarchical structure. This allows us to efficiently and accurately compute both the mass and the abundance of every mass state of a small to medium-sized molecule, whose gross structures include small number of fine structures. A truncated calculation of this algorithm can be applied to calculate a majority of isotopic species (99.99% of cumulative abundance) of a large molecule. 相似文献
55.
Qi Lin Hao Lan Chunmiao Ma Ryan T. Stendall Prof. Kenneth Shankland Dr. Rebecca A. Musgrave Dr. Peter N. Horton Dr. Carsten Baldauf Prof. Hans-Jörg Hofmann Prof. Craig P. Butts Dr. Manuel M. Müller Dr. Alexander J. A. Cobb 《Angewandte Chemie (International ed. in English)》2023,62(36):e202305326
We report the first NMR and X-ray diffraction (XRD) structures of an unusual 13/11-helix (alternating i, i+1 {NH−O=C} and i, i+3 {C=O−H−N} H-bonds) formed by a heteromeric 1 : 1 sequence of α- and δ-amino acids, and demonstrate the application of this framework towards catalysis. Whilst intramolecular hydrogen bonds (IMHBs) are the clear driver of helix formation in this system, we also observe an apolar interaction between the ethyl residue of one δ-amino acid and the cyclohexyl group of the next δ-residue in the sequence that seems to stabilize one type of helix over another. To the best of our knowledge this type of additional stabilization leading to a specific helical preference has not been observed before. Critically, the helix type realized places the α-residue functionalities in positions proximal enough to engage in bifunctional catalysis as demonstrated in the application of our system as a minimalist aldolase mimic. 相似文献
56.
Cobb AJ 《Organic & biomolecular chemistry》2007,5(20):3260-3275
The synthesis of modified nucleic acids has been the subject of much study ever since the structure of DNA was elucidated by Watson and Crick at Cambridge and Wilkins and Franklin at King's College over half a century ago. This review describes recent developments in the synthesis and application of these artificial nucleic acids, predominantly the phosphoramidites which allow for easy inclusion into oligonucleotides, and is divided into three separate sections. Firstly, modifications to the base portion will be discussed followed secondly by modifications to the sugar portion. Finally, changes in the type of nucleic acid linker will be discussed in the third section. Peptide Nucleic Acids (PNAs) are not discussed in this review as they represent a separate and large area of nucleic acid mimics. 相似文献
57.
58.
In this new century, nanotechnology has evolved from a novel concept to an integral aspect of product advancement. With an increasing presence of nanomaterials in commercial products, more concern about the impact of nanomaterials on human health and also the environment has been considered and evaluated. Fullerenes (C60), have been studied in several different areas and applied widely. Wider application of fullerenes into different products in the recent decades has increased the potential of fullerene releases into the environment. Fullerene research involves physical and chemical characteristics, toxicity, environment fate, and interaction with other pollutions. However, few studies have addressed fullerene quantification in solid matrices. Standardized artificial sediment was prepared following OECD guideline 225, and extracted C60 was quantified by HPLC–UV. A normal shaking method was employed for extraction for two times. Extracts were concentrated and analyzed. Recovery results revealed up to 90.7 ± 4.5%, 90.0 ± 3.8%, 93.8 ± 5.4%, respectively for 1.62, 0.65, and 0.32 μg/g C60 in dry sediment, which shows no significant difference between different concentration levels. Furthermore, extraction efficiency did not show significant difference while using TelfonTM tubes (96.5 ± 6.0%) or silanized glass vessels (90.7 ± 4.5%). This indicated that relative low cost is required for the method to be initially started in any lab. This technique has also been applied in the determination of C60 in sediment samples collected after a 10 day benthic exposure study. Extraction precision has been increased from 4.5% (S.D.) as the validation value up to 15.4% (RSD%) or more. The increased inhomogeneity by bioturbation and matrix complexity of the sediment after the toxicity test could both lower the extraction precision. 相似文献
59.
Herein, we report the synthesis of novel phenylalanine and tyrosine derivatives containing a N-methyliminodiacetic acid boronate group. These compounds can be prepared enantiomerically pure, they are stable to column chromatography and they can be stored in air for two months without degradation occurring. This new class of boronate containing aromatic amino acids has potential applications in both peptide chemistry and natural product synthesis. 相似文献
60.
Adamson P Auty DJ Ayres DS Backhouse C Barr G Barrett WL Bishai M Blake A Bock GJ Boehnlein DJ Bogert D Bower C Budd S Cavanaugh S Cherdack D Childress S Choudhary BC Coelho JA Cobb JH Coleman SJ Corwin L Cravens JP Cronin-Hennessy D Danko IZ de Jong JK Devenish NE Diwan MV Dorman M Escobar CO Evans JJ Falk E Feldman GJ Frohne MV Gallagher HR Gomes RA Goodman MC Gouffon P Gran R Grant N Grzelak K Habig A Harris D Harris PG Hartnell J Hatcher R Himmel A Holin A Huang X Hylen J Ilic J Irwin GM 《Physical review letters》2010,105(15):151601
We searched for a sidereal modulation in the MINOS far detector neutrino rate. Such a signal would be a consequence of Lorentz and CPT violation as described by the standard-model extension framework. It also would be the first detection of a perturbative effect to conventional neutrino mass oscillations. We found no evidence for this sidereal signature, and the upper limits placed on the magnitudes of the Lorentz and CPT violating coefficients describing the theory are an improvement by factors of 20-510 over the current best limits found by using the MINOS near detector. 相似文献