Does the light shift drive frequency aging in the rubidium atomic clock?

Frequency aging in the rubidium (Rb) vapor-cell atomic clock plays a significant role in the device's timekeeping ability. Though many researchers have speculated on the physical mechanism(s) driving the linear, deterministic frequency change (i.e., deltaf(t)/fo = At), there is little unambiguous experimental data regarding the phenomenon. Here, long-term data were used from on-orbit global positioning system (GPS) Rb clocks to examine one postulated mechanism for frequency aging (i.e., the light-shift effect). Defining the light shift of the clock's fractional frequency as alphaI/Io, where alpha is the light-shift coefficient, we find that temporal variations of the relative light intensity, I/Io, cannot account for frequency aging. However, for the population of clocks considered here, we obtain the intriguing result that alpha/A = 1.7 +/- 1.5. Thus, it may be that frequency aging is driven by the light-shift effect through temporal variations of the light-shift coefficient.     

Effectiveness of strategic environmental assessment in Germany? – meta-review of SEA research in the light of effectiveness dimensions

SEA practice in Germany has been growing since its introduction and so has the number of SEA research projects and publications. This paper provides a meta-review of German SEA effectiveness research published between 2004 and 2018. In this context, we discuss: (1) What is the status quo of SEA application in Germany? (2) What dimensions of SEA effectiveness have been addressed in research to date? and (3) How effective is SEA in Germany? Our findings indicate that there is room and need for SEA improvement, for example, with regards to the practice of screening, transparency, and quality management. With a focus of previous SEA research on the dimension of procedural effectiveness, future research should aim at other dimensions and their interactions (substantive, transactive, knowledge and learning, legitimacy).     

Kinematical studies of the glass transition in glassy Se80 ? xTe20Sbx

The present paper reports kinematic studies of the glass transition in glassy Se_80-xTe₂₀Sb_x alloys using the differential scanning calorimetric technique. The glass transition temperature (T_g) is found to increase monotonically with the heating rate. T_g also increases with the increase of Sb concentration in ternary Se_80-xTe₂₀Sb_x system. From the heating rate dependence of glass transition temperature, the activation energy ( E_t) for the relaxation time controlling the structural enthalpy, is calculated. The composition dependence of T_g and E_t is discussed in terms of the structure of the Se-Te-Sb glassy system.     

Which emission sources are responsible for the volatile organic compounds in the atmosphere of Pearl River Delta?

A field measurement study of volatile organic compounds (VOCs) was simultaneously carried out in October-December 2007 at an inland Pearl River Delta (PRD) site and a Hong Kong urban site. A receptor model i.e. positive matrix factorization (PMF) was applied to the data for the apportionment of pollution sources in the region. Five and six sources were identified in Hong Kong and the inland PRD region, respectively. The major sources identified in the region were vehicular emissions, solvent use and biomass burning, whereas extra sources found in inland PRD included liquefied petroleum gas and gasoline evaporation. In Hong Kong, the vehicular emissions made the most significant contribution to ambient VOCs (48 ± 4%), followed by solvent use (43 ± 2%) and biomass burning (9 ± 2%). In inland PRD, the largest contributor to ambient VOCs was solvent use (46 ± 1%), and vehicular emissions contributed 26 ± 1% to ambient VOCs. The percentage contribution of vehicular emission in Hong Kong in 2007 is close to that obtained in 2001-2003, whereas in inland PRD the contribution of solvent use to ambient VOCs in 2007 was at the upper range of the results obtained in previous studies and twice the 2006 PRD emission inventory. The findings advance our knowledge of ozone precursors in the PRD region.     

Does attention capacity moderate the effect of driver distraction in older drivers?

With age, a decline in attention capacity may occur and this may impact driving performance especially while distracted. Although the effect of distraction on driving performance of older drivers has been investigated, the moderating effect of attention capacity on driving performance during distraction has not been investigated yet. Therefore, the aim was to investigate whether attention capacity has a moderating effect on older drivers’ driving performance during visual distraction (experiment 1) and cognitive distraction (experiment 2). In a fixed-based driving simulator, older drivers completed a driving task without and with visual distraction (experiment 1, N = 17, mean age 78 years) or cognitive distraction (experiment 2, N = 35, mean age 76 years). Several specific driving measures of varying complexity (i.e., speed, lane keeping, following distance, braking behavior, and crashes) were investigated. In addition to these objective driving measures, subjective measures of workload and driving performance were also included. In experiment 1, crash occurrence increased with visual distraction and was negatively related to attention capacity. In experiment 2, complete stops at stop signs decreased, initiation of braking at pedestrian crossings was later, and crash occurrence increased with cognitive distraction. Interestingly, for a measure of lane keeping (i.e., standard deviation of lateral lane position (SDLP)), effects of both types of distraction were moderated by attention capacity. Despite the decrease of driving performance with distraction, participants estimated their driving performance during distraction as good. These results imply that attention capacity is important for driving. Driver assessment and training programs might therefore focus on attention capacity. Nonetheless, it is crucial to eliminate driver distraction as much as possible given the deterioration of performance on several driving measures in those with low and high attention capacity.     

Does the concept of safety culture help or hinder systems thinking in safety?

The concept of safety culture has become established in safety management applications in all major safety-critical domains. The idea that safety culture somehow represents a “systemic view” on safety is seldom explicitly spoken out, but nevertheless seem to linger behind many safety culture discourses. However, in this paper we argue that the “new” contribution to safety management from safety culture never really became integrated with classical engineering principles and concepts. This integration would have been necessary for the development of a more genuine systems-oriented view on safety; e.g. a conception of safety in which human, technological, organisational and cultural factors are understood as mutually interacting elements. Without of this integration, researchers and the users of the various tools and methods associated with safety culture have sometimes fostered a belief that “safety culture” in fact represents such a systemic view about safety. This belief is, however, not backed up by theoretical or empirical evidence. It is true that safety culture, at least in some sense, represents a holistic term—a totality of factors that include human, organisational and technological aspects. However, the departure for such safety culture models is still human and organisational factors rather than technology (or safety) itself. The aim of this paper is to critically review the various uses of the concept of safety culture as representing a systemic view on safety. The article will take a look at the concepts of culture and safety culture based on previous studies, and outlines in more detail the theoretical challenges in safety culture as a systems concept. The paper also presents recommendations on how to make safety culture more systemic.     

Does the performance of wet granulation and tablet hardness affect the drug dissolution profile of carvedilol in matrix tablets?

Wet granulation is mostly used process for manufacturing matrix tablets. Compared to the direct compression method, it allows for a better flow and compressibility properties of compression mixtures. Granulation, including process parameters and tableting, can influence critical quality attributes (CQAs) of hydrophilic matrix tablets. One of the most important CQAs is the drug release profile. We studied the influence of granulation process parameters (type of nozzle and water quantity used as granulation liquid) and tablet hardness on the drug release profile. Matrix tablets contained HPMC K4M hydrophilic matrix former and carvedilol as a model drug. The influence of selected HPMC characteristics on the drug release profile was also evaluated using two additional HPMC batches. For statistical evaluation, partial least square (PLS) models were generated for each time point of the drug release profile using the same number of latent factors. In this way, it was possible to evaluate how the importance of factors influencing drug dissolution changes in dependence on time throughout the drug release profile. The results of statistical evaluation show that the granulation process parameters (granulation liquid quantity and type of nozzle) and tablet hardness significantly influence the release profile. On the other hand, the influence of HPMC characteristics is negligible in comparison to the other factors studied. Using a higher granulation liquid quantity and the standard nozzle type results in larger granules with a higher density and lower porosity, which leads to a slower drug release profile. Lower tablet hardness also slows down the release profile.     

Does prestige dimension influence the interdisciplinary performance of scientific entities in knowledge flow? Evidence from the e-government field

Scientometrics - It has long been understood that knowledge flow can be divided into knowledge integration and knowledge diffusion and can be investigated by interdisciplinary scientific research...     

Can the HML's sliced BOMAB phantom be used in any whole body counter with a reduced number of sources?

The sliced Bottle Manikin Absorber (BOMAB) phantom was originally proposed as an alternative to a commercially available phantom, but it suffers from the disadvantage of containing over 160 sources that need to be manufactured; however, it was found that the number of slices could be reduced substantially and that two slices in the sliced phantom gave the same performance characteristics over a wide energy range as a conventional BOMAB phantom for a particular counting system. This work explores the adaptability of this phantom to another counting geometry. The response of the Human Monitoring Laboratory's whole-body counter measuring this phantom with a decreasing number of planar sources has been modelled using MCNP5 over a wide energy range (122-2754 keV). It was found that the best agreement was obtained when the phantom contained 10 sources, 1 in the mid point of each section. As this is a different result from a previous finding, any other counting geometry will have to be assessed to determine the optimum loading if the sliced phantom is to be used. Also, it is clear that this type of phantom cannot be used for an intercomparison that will encounter different counting geometries, unless it contains a full loading of sources.     

Does a pro-angiogenic state exist in the bone–implant interface of aseptically loosened joint prosthesis?

Neovascularization is indispensable to both bone remodeling and the development of chronic inflammation. A pro-angiogenic state in the periprosthetic tissue may augment the inflammatory response to wear debris. To investigate if a pro-angiogenic state exists in the bone-implant interface of aseptically loosened joint prosthesis, the expression of vascular endothelial growth factor (VEGF) and its receptor Flk-1/KDR were studied by immunohistochemistry. The VEGF-Flk/KDR pathway has been implicated as a key signaling requirement for pathological angiogenesis. The level of vascularization in periprosthetic tissue was semi-quantitatively compared to osteoarthritic (OA) and rheumatoid arthritic (RA) synovium. The level of vascularization in areas of periprosthetic tissue with heavy or low/moderate wear debris were also compared semi-quantitatively by image analysis. High levels of VEGF expression (16/16 cases) particularly in the implant synovial-like lining layer together with Flk-1/KDR expression by endothelial cells (13/16), suggests that neovascularization is occurring. Morphometric comparison of periprosthetic tissue with RA and OA synovium revealed no significant difference in microvessel density, but did reveal significantly increased microvessel area in RA synovium (P > 0.05). Areas of high wear debris infiltrate also contained a significantly smaller microvessel area (P > 0.01). Suggesting that wear debris may cause behavioral modification of microvessels. Modifying angiogenesis in the periprosthetic tissue could be a potential therapeutic target in reducing inflammation.     

What can the drivers’ own description from combined sources provide in an analysis of driver distraction and low vigilance in accident situations?

Accident data play an important role in vehicle safety development. Accident data sources are generally limited in terms of how much information is provided on driver states and behaviour prior to an accident. However, the precise limitations vary between databases, due to differences in analysis focus and data collection procedures between organisations. If information about a specific accident can be retrieved from more than one data source it should be possible to combine the available information sets to facilitate data from one source to compensate for limitations in the other(s). To investigate the viability of such compensation, this study identified a set of accidents recorded in two different data sources. The first data source investigated was an accident mail survey and the second data source insurance claims documents consisting predominantly of insurance claims completed by the involved road users. An analysis of survey variables was compared to a case analysis including word data derived from the same survey and filed insurance claims documents. For each accident, the added value of having access to more than one source of information was assessed. To limit the scope of this study, three particular topics were investigated: available information on low vigilance (e.g., being drowsy, ill); secondary task distraction (e.g., talking with passengers, mobile phone use); and distraction related to the driving task (e.g., looking for approaching vehicles). Results suggest that for low vigilance and secondary task distraction, a combination of the mail survey and insurance claims documents provide more reliable and detailed pre-crash information than survey variables alone. However, driving related distraction appears to be more difficult to capture. In order to gain a better understanding of the above issues and how frequently they occur in accidents, the data sources and analysis methods suggested here may be combined with other investigation methods such as in-depth accident investigations and pre-crash data recordings.     

Does faculty disciplinary background play a role in the publication pattern of an interdisciplinary research area? The case of science education in Brazil

Scientometrics - Research in the Social Sciences and Humanities is published in a variety of formats and types of documents. Local journals are relevant for these fields, particularly in...     

Does quality matter for innovations in low income markets? The case of the Kenyan mobile phone sector

Growing interest in lower income groups as consumers in emerging and developing markets has led to discussion on the issue of product quality, but so far work has generally focussed on simple goods rather than technology and innovations. However with innovations, one would expect that product quality would be more crucial in order to push trust of complex products amongst inexperienced users. Thus, this paper seeks to build understanding around issues around quality of innovations; focussing on what quality declines mean for vulnerable low income groups, and the types of policy approach that can be undertaken to improve quality.Research was undertaken in the mobile phone sector in Kenya where firms have increasingly focussed on diffusion amongst low income consumers. Here it was found that quality has become an increasing contested and problematic terrain. In the short term, decline in quality is often acceptable for inexperienced low income users, but in the longer term this becomes detrimental to innovations both in terms of trust and expense amongst consumers, as well as effecting the livelihoods of informal entrepreneurs who are often part of delivery of innovations to low income groups.Policy around quality was found to be present, but was limited by two key tenets. First, where implementation actors were unclear, public standards on quality tended to collapse into private standards followed only by diligent firms. Second, standards were often applied at a firm level which missed out on issues emerging amongst downstream diffusion actors often involved in adaptations which linked to quality variability.Undertaken and focussed correctly, policy on product quality drives diffusion of innovation and supports a level playing field, which in the long term supports more inclusive innovations. A lack of focussed policy can lead to the risk of rejection of innovation and ‘big bang’ policy interventions that are detrimental to the trust in innovations amongst low income groups.     

Does safety climate predict safety performance in Italy and the USA? Cross-cultural validation of a theoretical model of safety climate

Previous studies have acknowledged the relevance of assessing the measurement equivalence of safety related measures across different groups, and demonstrating whether the existence of disparities in safety perceptions might impair direct group comparisons. The Griffin and Neal (2000) model of safety climate, and the accompanying measure (Neal et al. [NGH], 2000), are both widely cited and utilized. Yet neither the model in its entirety nor the measure have been previously validated across different national contexts. The current study is the first to examine the NGH measurement equivalence by testing whether their model of safety climate predicting safety performance is tenable in both English speaking and non-English speaking countries. The study involved 616 employees from 21 organizations in the US, and 738 employees from 20 organizations in Italy. A multi-group confirmatory factor analytic approach was used to assess the equivalence of the measures across the two countries. Similarly, the structural model of relations among the NGH variables was examined in order to demonstrate its cross-country invariance. Results substantially support strict invariance across groups for the NGH safety scales. Moreover, the invariance across countries is also demonstrated for the effects of safety climate on safety knowledge and motivation, which in turn positively relate to both compliance and participation. Our findings have relevant theoretical implications by establishing measurement and relational equivalence of the NGH model. Practical implications are discussed for managers and practitioners dealing with multi-national organizational contexts. Future research should continue to investigate potential differences in safety related perceptions across additional non-English speaking countries.     

Does the probability of DWI arrest fall following participation in DWI and hybrid drug treatment court programs?

Using North Carolina administrative data, this study examined recidivism following participation in specialty hybrid drug and driving while intoxicated (DWI) court programs. Three court program participation levels were considered—being referred to, enrolling in, and completing a specialty court program. Measures of DWI recidivism were: arrest and total number of arrests for DWI, and being convicted of DWI during follow-up periods of two and, alternatively, four years. Propensity score matching was used to obtain comparable control groups. Using a four-year follow-up, persons convicted of a DWI who completed a specialty court program were associated with a greater reduction in DWI re-arrests and re-convictions than did matched individuals who were never referred to a specialty court program. DWI courts were more effective in reducing re-arrests than hybrid drug courts were. Although promising from the vantage point of participants, few persons convicted of a DWI were referred to either court type, thus limiting this strategy’s potential effectiveness in reducing DWI.     

Managing children's risk of injury in the home: Does parental teaching about home safety reduce young children's hazard interactions?

Past research confirms that parents extend much effort to teach their young children about safety, but little is known about this process. The present study examined mothers’ use of teaching as a strategy to manage young children's risk of home injury and how this impacts children's hazard interactions. Mothers of three-year-olds completed an in-home room-by-room interview in which they identified injury hazards that concern them, reported on use of teaching to manage risk of injury from these hazards, rated children's understanding of these safety issues and compliance with behavioral guidelines regarding these safety issues, and reported on children's recent interactions with these hazards. They also completed questionnaire measures of how difficult the child is to manage and the child's typical level of risk taking. Results revealed that children's understanding of safety impacted both their compliance and hazard interactions, moderating the impact of risk taking on compliance and also the impact of children's difficult-to-manage score on hazard interactions. These findings demonstrate that teaching strategies need to effectively enhance children's understanding of the safety issue in order to reduce children's risk of hazard interactions.     

Does the presence of an arteriovenous fistula alter changes in body water following hemodialysis as determined by multifrequency bioelectrical impedance assessment?

Multifrequency bioelectrical impedance assessments (MFBIAs) aid clinical assessment of hydration status for hemodialysis (HD) patients. Many MFBIA devices are restricted to whole body measurements and as many patients dialyze using arteriovenous fistulas (AVFs), we wished to determine whether AVFs affected body water measurements. We reviewed pre‐ and post‐HD segmental MFBIA measurements in 229 patients attending for midweek HD sessions. Up to 144 were dialyzed with a left arm AVF (L‐AVF), 42 with a right arm AVF (R‐AVF), and 43 by central venous access catheter (CVC). Water content and lean tissue were greater in the left compared to right arm in those patients with L‐AVFs both pre and post dialysis (pre 2.1 ± 0.7 vs. 2.0 ± 0.7 L, and post 1.9 ± 0.6 vs. 1.8 ± 0.6 L and pre 2.65 ± 0.9 vs. 2.56 ± 0.8 kg, and post 2.34 ± 0.8 vs. 2.48 ± 0.8 vs. 2.34 ± 0.8 kg, respectively) and were also greater in the right compared to left arm for those patients dialyzing with R‐AVFs (pre‐HD 1.92 ± 0.5 vs. 1.86 ± 0.6 L and post‐HD 1.79 ± 0.5 vs. 1.7 ± 0.5 L, and pre‐HD 2.47 ± 0.6 vs. 2.38 ± 0.7 kg and post‐HD 2.3 ± 0.74 vs. 1.28 ± 0.7 kg, respectively), all Ps < 0.05. There were no significant differences in arm volumes or composition pre or post dialysis in those dialyzing with CVCs. Segmental MFBIA detects differences in arm water and lean mass in patients with AVFs. The presence on an AVF increases the water content in the ipsilateral arm both pre and post HD. This increased water content of the fistula arm will not be detected by whole body bioimpedance devices.     

Does the domain of technology impact user trust? Investigating trust in automation across different consumer-oriented domains in young adults,military, and older adults

Trust has been shown to be a determinant of automation usage and reliance. Thus, understanding the factors that affect trust in automation has been a focus of much research. Despite the increased appearance of automation in consumer-oriented domains, the majority of research examining human-automation trust has occurred in highly specialised domains (e.g. flight management, military) and with specific user groups. We investigated trust in technology across three different groups (young adults, military, and older adults), four domains (consumer electronics, banking, transportation, and health), two stages of automation (information and decision automation), and two levels of automation reliability (low and high). Our findings suggest that trust varies on an interaction of domain of technology, reliability, stage, and user group.     

Does an expert-based evaluation allow us to go beyond the Impact Factor? Experiences from building a ranking of national journals in Poland

The article discusses the process of textually mediated communication in science and proposes an approach that complements citation analysis. Namely, it addresses the question of how the author’s text is read by the reader and whether the reader interprets the text in the same manner as the author. Fifty-seven scholarly contributions (articles, book chapters and book reviews), written by three social scientists, were content analyzed with the help of the QDA Miner and WordStat computer programs. The outcomes of the qualitative coding were compared with the outcomes of the analysis of word co-occurrences and the outcomes of the analysis on the basis of a dictionary based on substitution. Our findings suggest that texts have plural interpretations. Depending on the reading context, either the author’s or the reader’s perspective prevails. Also, both the author and the reader may read the text in a either deep or perfunctory manner. Deep reading necessitates spending significant time and cognitive resources.     

Does scientific eminence endure? Making sense of the most cited economists,psychologists and sociologists in textbooks (1970–2010)

This paper examines the concept of textbook eminence and asks whether this specific form of scholarly recognition is of a temporal rather than enduring nature. Based on an analysis of 30 leading textbooks in economics, psychology and economics from the 1970s and 2010s, it is established that less than a third of all eminent scholars remain across the period as the most cited authors. Therefore, the average “half-life” of textbook eminence is shorter than half a century. Textbook eminence, it seems, is associated first and foremost with ‘certified recognition,’ expressed through encyclopedia entries dedicated to individual scholars. In psychology, and partly in sociology, citation impact turns out to be a further significant correlate. In economics, however, textbook eminence is completely detached from peer recognition, as measured by the h-index. The identified short “half-life” of textbook eminence does not necessarily imply a replacement of older elites by younger researchers. In sociology, very few 20th century newcomers have yet attained textbook eminence.