Numbers,scale and symbols: the public understanding of nanotechnology

Nanotechnology will be an increasing part of the everyday lives of most people in the world. There is a general recognition that few people understand the implications of the technology, the technology itself or even the definition of the word. This lack of understanding stems from a lack of knowledge about science in general but more specifically difficulty in grasping the size scale and symbolism of nanotechnology. A potential key to informing the general public is establishing the ability to comprehend the scale of nanotechnology. Transitioning from the macro to the nanoscale seems to require an ability to comprehend scales of one-billion. Scaling is a skill not common in most individuals and tests of their ability to extrapolate size based upon scaling a common object demonstrates that most individuals cannot scale to the extent needed to make the transition to nanoscale. Symbolism is another important vehicle to providing the general public with a basis to understand the concepts of nanotechnology. With increasing age, individuals are able to draw representations of atomic scale objects, but these tend to be iconic and the different representations not easily translated. Ball and stick models are most recognized by the public, which provides an opportunity to present not only useful symbolism but also a reference point for the atomic scale.     

Selective perception of novel science: how definitions affect information processing about nanotechnology

This study examines how familiarity with an issue—nanotechnology—moderates the effect of exposure to science information on how people process mediated messages about a complex issue. In an online experiment, we provide a nationally representative sample three definitions of nanotechnology (technical, technical applications, and technical risk/benefit definitions). We then ask them to read an article about the topic. We find significant interactions between perceived nano-familiarity and the definition received in terms of how respondents perceive favorable information conveyed in the stimulus. People less familiar with nanotechnology were more significantly affected by the type of definition they received.     

Value chain of nanotechnology: a comparative study of some major players

The article provides a general overview for the landscapes of national nanotechnology development from 1991 to 2010. More than 230,000 unique patents are identified based on a composite search strategy in the Derwent innovation index database. According to the concordance between patent classification and industry technology, some main application areas are identified to compare the positions and specializations among the leading countries. By extracting the content of the “use” subfield in the abstracts and harvesting the keywords representing characteristics of life cycle, nanotechnology patents are grouped into four categories: nanomaterials, nanointermediates, nano-enabled products, and nanotools, which can be seen as four stages of nanotechnology’s value chain. These analyses enable us to identify the distributions of value chain and prolific research institutions among the leading countries. It is found that China is productive in nanomaterials and nanointermediates, rather than nano-enabled products and nanotools, which could be mainly explained by the fact that Chinese academia makes a main contribution to nanotechnology patenting. However, there is a big gap between university patenting and market demands, leading to a low rate of technology transfer or licensing.     

Weighted complex network analysis of travel routes on the Singapore public transportation system

The structure and properties of public transportation networks have great implications for urban planning, public policies and infectious disease control. We contribute a complex weighted network analysis of travel routes on the Singapore rail and bus transportation systems. We study the two networks using both topological and dynamical analyses. Our results provide additional evidence that a dynamical study adds to the information gained by traditional topological analysis, providing a richer view of complex weighted networks. For example, while initial topological measures showed that the rail network is almost fully connected, dynamical measures highlighted hub nodes that experience disproportionately large traffic. The dynamical assortativity of the bus networks also differed from its topological counterpart. In addition, inspection of the weighted eigenvector centralities highlighted a significant difference in traffic flows for both networks during weekdays and weekends, suggesting the importance of adding a temporal perspective missing from many previous studies.     

乘客对北京公交车内噪声感知的社会调查

本文通过社会声学调查的方法研究了乘客对公交车内噪声的感知情况。问卷内容主要包括乘客的人口统计学信息以及乘客对噪声的识别、反映、感受的若干问题。通过对问卷的描述性统计和卡方检验得出:车辆发动机以及乘客打电话、聊天的噪声是车内噪声的主要来源,也是乘客显著反感的噪声。车内噪声已经影响到了乘客的正常交流,也成为影响乘客因长时间乘坐引起心烦和疲劳的原因。鉴于以上影响乘客在有对座位的选择权时往往可能会偏向噪声影响小的位置。综合分析得出乘客对公交车内噪声感知偏向于比较吵闹、影响不大和有点厌恶。此外,对乘客的人口统计学差异做了进一步分析得出:吵闹程度、烦恼程度在性别、学历、年龄上不存在显著性差异;在影响程度上性别有显著性差异,学历、年龄无显著性差异。公交车内噪声已经成为影响乘车环境的重要因素之一,对公交车内噪声需要提高重视和加以控制。     

Categorical perception of intonation contrasts: effects of listeners' language background

Intonation perception of English speech was examined for English- and Chinese-native listeners. F0 contour was manipulated from falling to rising patterns for the final words of three sentences. Listener's task was to identify and discriminate the intonation of each sentence (question versus statement). English and Chinese listeners had significant differences in the identification functions such as the categorical boundary and the slope. In the discrimination functions, Chinese listeners showed greater peakedness than English peers. The cross-linguistic differences in intonation perception were similar to the previous findings in perception of lexical tones, likely due to listeners' language background differences.     

A comparative study of ESD of positive and negative ions from CO on tungsten

Electron stimulated desorption of O^? ions has been demonstrated from the CO/W system. Ion yields are shown to be approximately a factor of 50 smaller for O^? than for O⁺. The O^? species is shown to originate from both α-CO adsorption states with an estimated 80% of the O^? signal coming from the CO⁺ producing α-state. Preliminary results indicate that the ion energy distribution for O^? is broader and peaks at a higher energy than for the O⁺ ions.     

Interplay of negative pressure and hydrogen chemical effects in CeRhSn from first principles

Investigations within the local spin density functional theory (LSDF) of the intermetallic hydride system CeRhSnH_x were carried out for discrete model compositions in the range 0.33 ≤x_H ≤ 1.33 with the purpose of assessing the change of the cerium valence state in the neighborhood of the experimental hydride composition, CeRhSnH_0.8. In agreement with experiment, the analyses of the electronic and magnetic structures and of the chemical bonding properties point to trivalent cerium for 1 ≤x_H ≤ 1.33. In contrast, for lower hydrogen amounts the hydride system stays in an intermediate-valent state for cerium, like in CeRhSn. The influence of the insertion of hydrogen is addressed from both the volume expansion and chemical bonding effects. The latter are found to have the main influence on the change of Ce valence character. Spin polarized calculations point to a finite magnetic moment carried by the Ce 4f states; its magnitude increases with x_H in the range 1 ≤x_H ≤ 1.33.     

The thermal effects on the negative refraction of sonic crystals

The thermal effects on the refractive direction of a sonic crystal consisted of steel rods in air background is investigated. By means of varying the temperature, the refractive direction and the range of the incident angle with the negative refraction are changed accordingly due to the variations of the air density and sound speed. The focus behaviors, intensity and distance, of the sonic crystal plane lens with varying temperature are studied. Moreover, at certain frequencies and incident angles, the refractive angles can be changed from negative to positive by varying the temperature of a sonic crystal with air background. The tunable sonic crystal can be used to design various novel ultrasonic devices.     

Enhancement of temporal periodicity cues in cochlear implants: effects on prosodic perception and vowel identification

Standard continuous interleaved sampling processing, and a modified processing strategy designed to enhance temporal cues to voice pitch, were compared on tests of intonation perception, and vowel perception, both in implant users and in acoustic simulations. In standard processing, 400 Hz low-pass envelopes modulated either pulse trains (implant users) or noise carriers (simulations). In the modified strategy, slow-rate envelope modulations, which convey dynamic spectral variation crucial for speech understanding, were extracted by low-pass filtering (32 Hz). In addition, during voiced speech, higher-rate temporal modulation in each channel was provided by 100% amplitude-modulation by a sawtooth-like wave form whose periodicity followed the fundamental frequency (F0) of the input. Channel levels were determined by the product of the lower- and higher-rate modulation components. Both in acoustic simulations and in implant users, the ability to use intonation information to identify sentences as question or statement was significantly better with modified processing. However, while there was no difference in vowel recognition in the acoustic simulation, implant users performed worse with modified processing both in vowel recognition and in formant frequency discrimination. It appears that, while enhancing pitch perception, modified processing harmed the transmission of spectral information.     

A parametric study of negative feedback Nd:YAG laser

The output pulse parameters of a mode-locked Nd:YAG laser with a passive negative feedback element were studied experimentally. The pulse evolution within the train was experimentally recorded using a modified second harmonic generation autocorrelator. By comparing the laser operation with and without an acousto-optic modulator, we found that with the later there is a significant increase in the mode locking probability and the pulse acquires a temporally Gaussian symmetric pulse shape. Further with the active modulator there is a relaxation in alignment tolerances and increase in the range of permissible dye concentrations for stable mode locking. It was also observed that the pulse width of the negative feedback laser depends on the saturation intensity of the mode locking dye and reduces for a dye with higher saturation intensity. The pulse width was also found to reduce linearly as the initial transmission of the dye is reduced.     

Addressing conflicts of interest in nanotechnology oversight: lessons learned from drug and pesticide safety testing

Financial conflicts of interest raise significant challenges for those working to develop an effective, transparent, and trustworthy oversight system for assessing and managing the potential human health and ecological hazards of nanotechnology. A recent paper in this journal by Ramachandran et al., J Nanopart Res, 13:1345–1371 (2011) proposed a two-pronged approach for addressing conflicts of interest: (1) developing standardized protocols and procedures to guide safety testing; and (2) vetting safety data under a coordinating agency. Based on past experiences with standardized test guidelines developed by the international Organization for Economic Cooperation and Development (OECD) and implemented by national regulatory agencies such as the U.S. Environmental Protection Agency (EPA) and Food and Drug Administration (FDA), we argue that this approach still runs the risk of allowing conflicts of interest to influence toxicity tests, and it has the potential to commit regulatory agencies to outdated procedures. We suggest an alternative approach that further distances the design and interpretation of safety studies from those funding the research. In case the two-pronged approach is regarded as a more politically feasible solution, we also suggest three lessons for implementing this strategy in a more dynamic and effective manner.     

Biological effects of weak electromagnetic fields from 0 Hz to 200 MHz: a survey of the literature with special emphasis on possible magnetic resonance effects

The literature on biological effects of weak electromagnetic fields of a frequency of 200 MHz or less is surveyed. The topic has been extraordinarily controversial, in part because of disputed assertions about a role for electromagnetic fields in carcinogenesis or production of abnormalities in growth and development. There is fairly widespread acceptance of certain beneficial effects, particularly the stimulation of healing. An increasing number of reports point to interactions between static magnetic fields and time-varying fields in the production of some effects. Safety implications are noted along with the hypothetical possibility of production of experimental artifacts by electromagnetic fields in MRS research.     

Making sense of policy choices: understanding the roles of value predispositions, mass media, and cognitive processing in public attitudes toward nanotechnology

Using a nationally representative telephone survey of 1,015 adults in the United States, this study examines how value predispositions, communication variables, and perceptions of risks and benefits are associated with public support for federal funding of nanotechnology. Our findings show that highly religious individuals were less supportive of funding of nanotech than less religious individuals, whereas individuals who held a high deference for scientific authority were more supportive of funding of the emerging technology than those low in deference. Mass media use and elaborative processing of scientific news were positively associated with public support for funding, whereas factual scientific knowledge had no significant association with policy choices. The findings suggest that thinking about and reflecting upon scientific news promote better understanding of the scientific world and may provide a more sophisticated cognitive structure for the public to form opinions about nanotech than factual scientific knowledge. Finally, heuristic cues including trust in scientists and perceived risks and benefits of nanotech were found to be associated with public support for nanotech funding. We conclude with policy implications that will be useful for policymakers and science communication practitioners.     

Stage effects of negative emotion on spatial and verbal working memory

Background  

The effects of negative emotion on different processing periods in spatial and verbal working memory (WM) and the possible brain mechanism of the interaction between negative emotion and WM were explored using a high-time resolution event-related potential (ERP) technique and time-locked delayed matching-to-sample task (DMST).     

On the study of the effects of sea views, greenery views and personal characteristics on noise annoyance perception at homes

Noise annoyance has caused significant adverse impacts on human beings and numerous efforts have been spent on mitigating annoyance problems. Natural greenery has been shown to be able to moderate annoyance problems at home but this conclusion was drawn without properly controlling the potential confounding factors. Furthermore, few have explored the moderation effect of a sea view. Accordingly, this study formulated a multivariate model to examine the impacts of natural views as well as personal characteristics on annoyance perception. A housing estate was selected in Hong Kong as the survey site for which some of the residents were exposed to greenery views, sea views, or both from their homes. Eight hundred and sixty-one responses were collected via questionnaire surveys and analyzed using an ordered logit model. The results suggest that both a greenery view and a sea view can moderate annoyance responses. Several individual's personal characteristics are found to affect individuals' annoyance perception. The duration of time spent daily at home is shown to have an influence on the moderation impact exerted by a greenery view, while the age of an individual is shown to have an influence on noise moderation effect exerted by a sea view.