646 research outputs found
How interdisciplinary is nanotechnology?
Facilitating cross-disciplinary research has attracted much attention in recent years, with special concerns in nanoscience and nanotechnology. Although policy discourse has emphasized that nanotechnology is substantively integrative, some analysts have countered that it is really a loose amalgam of relatively traditional pockets of physics, chemistry, and other disciplines that interrelate only weakly. We are developing empirical measures to gauge and visualize the extent and nature of interdisciplinary interchange. Such results speak to research organization, funding, and mechanisms to bolster knowledge transfer. In this study, we address the nature of cross-disciplinary linkages using “science overlay maps” of articles, and their references, that have been categorized into subject categories. We find signs that the rate of increase in nano research is slowing, and that its composition is changing (for one, increasing chemistry-related activity). Our results suggest that nanotechnology research encompasses multiple disciplines that draw knowledge from disciplinarily diverse knowledge sources. Nano research is highly, and increasingly, integrative—but so is much of science these days. Tabulating and mapping nano research activity show a dominant core in materials sciences, broadly defined. Additional analyses and maps show that nano research draws extensively upon knowledge presented in other areas; it is not constricted within narrow silos
Knowledge politics and new converging technologies: a social epistemological perspective
The “new converging technologies” refers to the prospect of advancing the human condition by the integrated study and application of nanotechnology, biotechnology, information technology and the cognitive sciences - or “NBIC”. In recent years, it has loomed large, albeit with somewhat different emphases, in national science policy agendas throughout the world. This article considers the political and intellectual sources - both historical and contemporary - of the converging technologies agenda. Underlying it is a fluid conception of humanity that is captured by the ethically challenging notion of “enhancing evolution”
Clinical applications of pharmacogenomics
Indexación: Scopus.Pharmacogenomics is an emergent field aimed at tailoring pharmacological therapy. Genetic polymorphisms can modify the expression and function of enzymes and proteins involved in drug metabolism, affecting absorption, distribution, biotransformation and excretion as well as the drug-target interaction. Therefore, the presence of allelic variants will classify people as poor, extensive or rapid/ultra rapid metabolizers, modifying drug efficacy and safety. In this work, the state of art in relation to this discipline is presented and the genetic variants of enzymes that are involved in drug pharmacokinetics or pharmacodynamics are described. The effects of these variants on the therapeutic response to drugs used in our country are also discussed.http://ref.scielo.org/4y6n8
Trends for nanotechnology development in China, Russia, and India
China, Russia, and India are playing an increasingly important role in global nanotechnology research and development (R&D). This paper comparatively inspects the paper and patent publications by these three countries in the Thomson Science Citation Index Expanded (SCI) database and United States Patent and Trademark Office (USPTO) database (1976–2007). Bibliographic, content map, and citation network analyses are used to evaluate country productivity, dominant research topics, and knowledge diffusion patterns. Significant and consistent growth in nanotechnology papers are noted in the three countries. Between 2000 and 2007, the average annual growth rate was 31.43% in China, 11.88% in Russia, and 33.51% in India. During the same time, the growth patterns were less consistent in patent publications: the corresponding average rates are 31.13, 10.41, and 5.96%. The three countries’ paper impact measured by the average number of citations has been lower than the world average. However, from 2000 to 2007, it experienced rapid increases of about 12.8 times in China, 8 times in India, and 1.6 times in Russia. The Chinese Academy of Sciences (CAS), the Russian Academy of Sciences (RAS), and the Indian Institutes of Technology (IIT) were the most productive institutions in paper publication, with 12,334, 6,773, and 1,831 papers, respectively. The three countries emphasized some common research topics such as “Quantum dots,” “Carbon nanotubes,” “Atomic force microscopy,” and “Scanning electron microscopy,” while Russia and India reported more research on nano-devices as compared with China. CAS, RAS, and IIT played key roles in the respective domestic knowledge diffusion
Do new Ethical Issues Arise at Each Stage of Nanotechnological Development?
The literature concerning ethical issues associated with nanotechnologies has become prolific. However, it has been claimed that ethical problems are only at stake with rather sophisticated nanotechnologies such as active nanostructures, integrated nanosystems and heterogeneous molecular nanosystems, whereas more basic nanotechnologies such as passive nanostructures mainly pose technical difficulties. In this paper I argue that fundamental ethical issues are already at stake with this more basic kind of nanotechnologies and that ethics impacts every kind of nanotechnologies, already from the simplest kind of engineered nanoproducts. These ethical issues are mainly associated with the social desirability of nanotechnologies, with the difficulties to define nanotechnologies properly, with the important uncertainties surrounding nanotechnologies, with the threat of ‘nano-divide’, and with nanotechnology as ‘dual-use technology’
Towards sustainable transformation: Research priorities in climate change and biodiversity
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By exploring key research gaps and challenges in climate change and biodiversity, this report offers insights into promoting transformative change through research and innovation. Developed through an open and participatory approach, the report builds on the extensive international network of researchers and innovators at Future Earth and beyond. It investigates research needs around topics such as planetary health, societal values, governance, the role of policy instruments, emerging tools, and new ways to work across sectors to implement and drive transformations. Through this transdisciplinary approach, the authors highlight the importance of innovative and inclusive methodologies to tackle sustainability challenges and advocate for collaborative funding initiatives to support these endeavours. The outcomes of this research agenda are crucial in directing and prioritising research funding, emphasising the imperative of systems change in addressing climate change and biodiversity loss
Measurement of the diffractive structure function in deep inelastic scattering at HERA
This paper presents an analysis of the inclusive properties of diffractive
deep inelastic scattering events produced in interactions at HERA. The
events are characterised by a rapidity gap between the outgoing proton system
and the remaining hadronic system. Inclusive distributions are presented and
compared with Monte Carlo models for diffractive processes. The data are
consistent with models where the pomeron structure function has a hard and a
soft contribution. The diffractive structure function is measured as a function
of \xpom, the momentum fraction lost by the proton, of , the momentum
fraction of the struck quark with respect to \xpom, and of . The \xpom
dependence is consistent with the form \xpoma where
in all bins of and
. In the measured range, the diffractive structure function
approximately scales with at fixed . In an Ingelman-Schlein type
model, where commonly used pomeron flux factor normalisations are assumed, it
is found that the quarks within the pomeron do not saturate the momentum sum
rule.Comment: 36 pages, latex, 11 figures appended as uuencoded fil
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Ultrafiltration based purification strategies for surfactin produced by bacillus subtilis lb5a using cassava wastewater as substrate
BACKGROUND: Bacillus subtilis synthesizes surfactin, a powerful surface-active agent. It has interesting potential applications. However, due to its high cost of production, commercial use is impracticable. The downstream processing represents ≈60% of production costs and the culture medium ≈30%. Many reports focused, separately, on production of surfactin using by-products (reduced cost) or the purification using synthetic medium. Therefore, the aim of this work was to evaluate, for the first time, the impact of using a by-product as fermentation medium on the downstream processing based on membrane filtration.
RESULTS: Membranes of PES-100-kDa efficiently retained surfactin micelles - the first step of ultrafiltration, whereas, the second step required membranes of 50-kDa to separate surfactin monomers from proteins. Ultrafiltration of crude biosurfactant was associated with fouling and/or concentration polarization resulting in lower purity than when synthetic medium was used. Further improvement in purity was achieved by partial removal of proteins prior to ultrafiltration by precipitation and extraction. The RMN and MALDI-TOFMS analyses identified 11 potential surfactin homologous composed by two amino acid sequences.
CONCLUSION: Production of surfactin using cassava wastewater as a low-cost culture medium and its purification by the 2-step ultrafiltration process is feasible, nevertheless, the higher protein content of this medium as compared to the synthetic one leads to a lower purity product; further increase in purity can be achieved by applying additional purification steps prior to ultrafiltration with the subsequent increased in process cost
Probing BFKL Dynamics in the Dijet Cross Section at Large Rapidity Intervals in ppbar Collisions at sqrt{s}=1800 and 630 GeV
Inclusive dijet production at large pseudorapidity intervals (delta_eta)
between the two jets has been suggested as a regime for observing BFKL
dynamics. We have measured the dijet cross section for large delta_eta in ppbar
collisions at sqrt{s}=1800 and 630 GeV using the DO detector. The partonic
cross section increases strongly with the size of delta_eta. The observed
growth is even stronger than expected on the basis of BFKL resummation in the
leading logarithmic approximation. The growth of the partonic cross section can
be accommodated with an effective BFKL intercept of
a_{BFKL}(20GeV)=1.65+/-0.07.Comment: Published in Physical Review Letter
Measurement of Jet Shapes in Photoproduction at HERA
The shape of jets produced in quasi-real photon-proton collisions at
centre-of-mass energies in the range GeV has been measured using the
hadronic energy flow. The measurement was done with the ZEUS detector at HERA.
Jets are identified using a cone algorithm in the plane with a
cone radius of one unit. Measured jet shapes both in inclusive jet and dijet
production with transverse energies GeV are presented. The jet
shape broadens as the jet pseudorapidity () increases and narrows
as increases. In dijet photoproduction, the jet shapes have been
measured separately for samples dominated by resolved and by direct processes.
Leading-logarithm parton-shower Monte Carlo calculations of resolved and direct
processes describe well the measured jet shapes except for the inclusive
production of jets with high and low . The observed
broadening of the jet shape as increases is consistent with the
predicted increase in the fraction of final state gluon jets.Comment: 29 pages including 9 figure
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