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1.
The 2011 AASHTO Roadside Design Guide (RDG) contains perhaps the most widely used procedure for choosing an appropriate length of need (LON) for roadside barriers. However, this procedure has several limitations. The procedure uses a highly simplified model of vehicle departure, and the procedure does not allow designers to specify an explicit level of protection. A new procedure for choosing LON that addresses these limitations is presented in this paper. This new procedure is based on recent, real-world road departure trajectories and uses this departure data in a more realistic way. The new procedure also allows LON to be specified for a precisely known level of protection – a level which can be based on number of crashes, injury outcomes or even estimated crash cost – while still remaining straightforward and quick to use like the 2011 RDG procedure.  相似文献   
2.
The relationship of depressed mood to cognitive disturbance in HIV infection was examined in a sample of 139 homosexual men. Ss were grouped according to the classification of the Centers for Disease Control: 39 were in Group IV, 62 were in Group II or Group III, and 38 were HIV-negative. Ss completed the Profile of Mood States and 10 neuropsychological tests. Analysis employing a classification approach indicated that, although symptoms of depression and neuropsychological impairment were more common in Ss who were HIV-positive, particularly those classified as Group IV, there were no systematic relationships between depression and neuropsychological impairment. Depressed mood and cognitive disturbance each seem to have unique associations to HIV illness status. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
3.
The influence of gas velocity (3.5, 10, and 18 mm/s), salt type (NaCl, NaF, NaBr, NaI and CsCl) and salt concentration (0.001-3 M) on bubble coalescence in a small bubble column were studied. The bubble coalescence was determined by the relative change in the measured light intensities passing through the salt solutions and clean deionised water. It was shown that the transition salt concentration for bubble coalescence inhibition (determined at 50% of bubble coalescence) of all investigated salts decreases with increasing superficial gas velocity. The difference in the transition concentration between NaCl, NaF, NaBr and CsCl does not significantly change with the gas velocity. However that difference between NaI and the other salts significantly decreases with increasing the gas velocity. The gas holdup significantly increases with NaCl, NaF, NaBr and CsCl concentrations but does not significantly change with NaI concentration. These new results imply that the transition salt concentration for bubble coalescence and gas holdup depend not only on the salt properties (i.e. the ion type and their combination) as previously reported, but also on the hydrodynamic conditions.  相似文献   
4.
This article discusses providing information literacy to interior design students, specifically how over a few years, and several assignment iterations, we moved from a more traditional one-shot library instruction session to a creative Association of College and Research Libraries Framework-inspired assignment using Pinterest as the medium for the students' professionally relevant research project. The outcome of our instruction relied on flexible assignment planning, collaboration as faculty and librarians changed roles, and a focus on information literacy skills needed by professional designers.  相似文献   
5.
The effect of total particulate matter (TPM) from cigarette smoke on the expression and binding properties of nicotinic acetylcholine receptors (nAChRs) was investigated using a human neuroblastoma cell line (SH-SY5Y). TPM but not nicotine on its own inhibited cell growth at nicotine concentrations above 5 microM. To examine effects on nAChR expression, intact cells were incubated with 3H-epibatidine, and a Bmax of 13 fmoles/10(5) cells (7.8 x 10(4) binding sites/cell) was measured in unexposed cells as well as in cells treated with 2 microM nicotine alone or with TPM containing 2 microM nicotine. Using Scatchard analysis, we measured a Kd of 0.3 nM for 3H-epibatidine binding to nAChRs. This Kd was increased to 1.3 nM by addition of nicotine or TPM extract, both at 2 microM nicotine. Bmax, however, was unaffected, suggesting competitive binding of nicotine to its receptor. Short-term and prolonged 3-day exposures of SH-SY5Y cells to either TPM or nicotine at nicotine concentrations ranging from 0.2 microM to 20 microM increased specific binding, suggesting upregulation of nAChR expression. Most significant, binding was consistently greater in cells pretreated with TPM than in cells pretreated with nicotine. We conclude that TPM contains compounds that are toxic to cells at high concentrations (cell growth inhibition) but that do not compete with nicotine for binding to nAChRs (Scatchard analysis). These non-nicotinic compounds are capable of increasing the expression of one or more of the nAChR subunits. Furthermore, our cell culture assay provides a useful in vitro model for assessing the relative addictiveness of different tobacco products, including that of non-nicotine components.  相似文献   
6.
Interaction forces between a multi-walled carbon nanotube (MWCNT) and an air-bubble in pure deionized water and methyl isobutyl carbinol (MIBC) solutions were measured by atomic force microscopy (AFM). The MWCNT terminated probe was brought into contact with the bubble at controlled applied forces. The repulsive steps followed by attractive jumps recorded in the approach force curves correspond to changes in the MWCNT diameter along its length, an observation confirmed by transmission electron microscopy (TEM) data. By processing the retraction part of the force curves obtained in pure water it is possible to estimate the end diameter of the carbon nanotube with nanometer resolution using a capillary force model.  相似文献   
7.
Porous metals are of interest for their high surface area and potential for enhanced catalytic behavior. Electrodeposited NiCu thin films with a range of compositions were electrochemically dealloyed to selectively remove the Cu component. The film structure, composition, and reactivity of these samples were characterized both before and after the dealloying step using scanning electron microscopy, energy-dispersive spectroscopy, and electrochemical measurements. The catalytic behavior of the dealloyed porous Ni samples towards the hydrogen evolution reaction was measured and compared to that of the as-deposited samples. The dealloyed samples were generally more reactive than their as-deposited counterparts at low overpotentials, making the dealloying procedure a promising area of exploration for improved hydrogen evolution catalysts.  相似文献   
8.
Over the past 5 decades, stand-replacing crown fires have increased in size and frequency throughout the long-needled pine forests of the American Southwest. Suppression of frequent, low-intensity ground fires has resulted in dense stands of fire-prone trees over large areas. Efforts to restore forest structure to conditions that would permit a return to historical fire regimes, characterized by frequent ground fire, are hindered by the inability of managers and the public to compare the effects of alternative forest management practices on fire behavior and a host of other issues. Currently, forest management is mired in controversy, endangering ecosystem function, biodiversity, public safety, and municipal watersheds. Our research program, motivated by the need to examine cumulative effects of many independent management decisions over large planning areas, focuses on the development of spatial data and modeling tools that enable diverse stakeholders to work together to guide landscape-scale planning efforts. Data layers describing forest composition and structure facilitate modeling of fire threat and wildlife habitat over areas of several hundred thousand hectares. Modeling alternative forest management scenarios via a collaborative, public process fosters informed discourse and helps conflicting parties forge appropriate policy and identify management responses that meet restoration objectives.  相似文献   
9.
10.
The information overload created by social media messages in emergency situations challenges response organizations to find targeted content and users. We aim to select useful messages by detecting the presence of conversation as an indicator of coordinated citizen action. Using simple linguistic indicators drawn from conversation analysis in social science, we model the presence of coordination in the communication landscape of Twitter1 using a corpus of 1.5 million tweets for various disaster and non-disaster events spanning different periods, lengths of time, and varied social significance. Within replies, retweets and tweets that mention other Twitter users, we found that domain-independent, linguistic cues distinguish likely conversation from non-conversation in this online form of mediated communication. We demonstrate that these likely conversation subsets potentially contain more information than non-conversation subsets, whether or not the tweets are replies, retweets, or mention other Twitter users, as long as they reflect conversational properties. From a practical perspective, we have developed a model for trimming the candidate tweet corpus to identify a much smaller subset of data for submission to deeper, domain-dependent semantic analyses for the identification of actionable information nuggets for coordinated emergency response.  相似文献   
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