bluuebunny/crossref_metadata_2025 huggingface dataset:
Sr isotopic characteristics in two small watersheds draining typical silicate and carbonate rocks: implication for the studies on seawater Sr isotopic evolution
Authors: Wu W. H. , Zheng H. B. , Yang J. D.
Published: June 2013

Abstract. We systematically investigated Sr isotopic characteristics of small silicate watershed – the tributary Xishui River of the Yangtze River, and small carbonate watershed – the tributary Guijiang River of the Pearl River. The results show that the Xishui River has relatively high Sr concentrations (0.468–1.70 μmol L−1 in summer and 1.30–3.17 μmol L−1 in winter, respectively) and low 87Sr/86Sr ratios (0.708686–0.709148 in summer and 0.708515–0.709305 in winter), which is similar to the characteristics of carbonate weathering. The Guijiang River has low Sr concentrations (0.124–1.098 μmol L−1) and high 87Sr/86Sr ratios (0.710558–0.724605), being characterized by silicate weathering. In the Xishui River catchment, chemical weathering rates in summer are far higher than those in winter, indicating significant influence of climate regime. However, slight differences of 87Sr/86Sr ratios between summer and winter show that influence of climate on Sr isotope is uncertainty owing to very similar Sr isotope values in silicate and carbonate bedrocks. As 87Sr/86Sr ratios in the Xishui River are lower than those in seawater, they will decrease 87Sr/86Sr ratio of seawater after transported into oceans. Previous studies also showed that some basaltic watersheds with extremely high chemical weathering rates reduced the seawater Sr isotope ratios. In other words, river catchments with high silicate weathering rates do not certainly transport highly radiogenic Sr into oceans. Therefore, it may be questionable that using the variations of seawater 87Sr/86Sr ratio to indicate the continental silicate weathering intensity. In the Guijiang River catchment, 87Sr/86Sr ratios of carbonate rocks and other sources (rainwater, domestic and industrial waste water, and agricultural fertilizer) are lower than 0.71. In comparison, some non-carbonate components, such as, sand rocks, mud rocks, shales, have relatively high Sr isotopic compositions. Moreover, granites accounted for only 5% of the drainage area have extremely high 87Sr/86Sr ratios with an average of over 0.8. Therefore, a few silicate components contained in carbonate rocks obviously increases the Sr isotopic compositions of the river water, and results in a positive effect on the rise of 87Sr/86Sr ratio of seawater. Therefore, the relation between Sr isotope evolution of seawater and continental weathering rate is complex, 87Sr/86Sr ratios of underlying bedrock in catchment could be an important controlling factors.
Figures of merit of thermoelectric and bolometric thermal radiation sensors
Authors: Dillner U. , Kessler E. , Meyer H.-G.
Published: June 2013

Abstract. Figures of merit condensing the performance parameters of radiation sensors such as responsivity, noise equivalent power, and time constant in a single number can be useful for rating the performance of a particular sensor in comparison to other ones or to fundamental performance limits. The classification system and the figures of merit of radiation sensors introduced by R. C. Jones are revisited for thermal radiation sensors with the focus on thermopiles and bolometers. As a result it is stated that radiation thermopiles and bolometers should be classified differently: type III detectors for thermopiles vs. type II detectors for bolometers. Modified figures of merit are suggested and relations between them given. The figures of merit are applied in an overview on state-of-the-art thermopiles and bolometers operated at room temperature.
Sample size matters: investigating the effect of sample size on a logistic regression debris flow susceptibility model
Authors: Heckmann T. , Gegg K. , Gegg A. , Becht M.
Published: June 2013

Abstract. Predictive spatial modelling is an important task in natural hazard assessment and regionalisation of geomorphic processes or landforms. Logistic regression is a multivariate statistical approach frequently used in predictive modelling; it can be conducted stepwise in order to select from a number of candidate independent variables those that lead to the best model. In our case study on a debris flow susceptibility model, we investigate the sensitivity of model selection and quality to different sample sizes in light of the following problem: on the one hand, a sample has to be large enough to cover the variability of geofactors within the study area, and to yield stable results; on the other hand, the sample must not be too large, because a large sample is likely to violate the assumption of independent observations due to spatial autocorrelation. Using stepwise model selection with 1000 random samples for a number of sample sizes between n = 50 and n = 5000, we investigate the inclusion and exclusion of geofactors and the diversity of the resulting models as a function of sample size; the multiplicity of different models is assessed using numerical indices borrowed from information theory and biodiversity research. Model diversity decreases with increasing sample size and reaches either a local minimum or a plateau; even larger sample sizes do not further reduce it, and approach the upper limit of sample size given, in this study, by the autocorrelation range of the spatial datasets. In this way, an optimised sample size can be derived from an exploratory analysis. Model uncertainty due to sampling and model selection, and its predictive ability, are explored statistically and spatially through the example of 100 models estimated in one study area and validated in a neighbouring area: depending on the study area and on sample size, the predicted probabilities for debris flow release differed, on average, by 7 to 23 percentage points. In view of these results, we argue that researchers applying model selection should explore the behaviour of the model selection for different sample sizes, and that consensus models created from a number of random samples should be given preference over models relying on a single sample.
Structure and Functions of Lactoferrin as Ingredient in Infant Formulas
Authors: Aly Esmat , Ros Gaspar , Frontela Carmen
Published: June 2013

It has been widely accepted that breastfeeding is the best food for newborns. Mother’s milk provides all the nutritive elements for normal growth and development of infants being considered the first functional food in life. Because it contains a variety of compounds playing a key role in the adequate feeding of newborns, such as oligosaccharides, probiotics, polyunsaturated fatty acids and lactoferrin. Lactoferrin from human milk has been demonstrated to be responsible for the resistance of newborns to infections and also has many biological activities that are essential for an adequate health of infants. Recently, there is also a growing interest in the potential use of lactoferrin for the improvement of bone health and cancer prevention. Milk substitutes and infant formulas play a vital role in infant nutrition when the breastfeeding is not available. The design of infant formula is modeled on the composition of human milk and the current trend in the infant formulas manufacturing is looking to provide not only nutritional compounds but also similar functional effects than human milk.
Tactile-Sight: A Sensory Substitution Device Based on Distance-Related Vibrotactile Flow
Authors: Cancar Leandro , Díaz Alex , Barrientos Antonio , Travieso David , Jacobs David M.
Published: June 2013

Sensory substitution is a research field of increasing interest with regard to technical, applied and theoretical issues. Among the latter, it is of central interest to understand the form in which humans perceive the environment. Ecological psychology, among other approaches, proposes that we can detect higher-order informational variables (in the sense that they are defined over substantial spatial and temporal intervals) that specify our interaction with the environment. When using a vibrotactile sensory substitution device, it is reasonable to ask if stimulation on the skin may be exploitable to detect higher-order variables. Motivated by this question, a portable vibrotactile sensory substitution device was built, using distance-based information as a source and driving a large number of vibrotactile actuators (72 in the reported version, 120 max). The portable device was designed to explore real environments, allowing natural unrestricted movement for the user while providing contingent real-time vibrotactile information. Two preliminary experiments were performed. In the first one, participants were asked to detect the time to contact of an approaching ball in a simulated (desktop) environment. Reasonable performance was observed in all experimental conditions, including the one with only tactile stimulation. In the second experiment, a portable version of the device was used in a real environment, where participants were asked to hit an approaching ball. Participants were able to coordinate their arm movements with vibrotactile stimulation in appropriate timing. We conclude that vibrotactile flow can be generated by distance-based activation of the actuators and that this stimulation on the skin allows users to perceive time-to-contact related environmental properties.
Continuous Surface Rendering, Passing from CAD to Physical Representation
Authors: Covarrubias Mario , Bordegoni Monica , Cugini Umberto
Published: June 2013

This paper describes a desktop-mechatronic interface that has been conceived to support designers in the evaluation of aesthetic virtual shapes. This device allows a continuous and smooth free hand contact interaction on a real and developable plastic tape actuated by a servo-controlled mechanism. The objective in designing this device is to reproduce a virtual surface with a consistent physical rendering well adapted to designers' needs. The desktop-mechatronic interface consists in a servo-actuated plastic strip that has been devised and implemented using seven interpolation points. In fact, by using the MEC (Minimal Energy Curve) Spline approach, a developable real surface is rendered taking into account the CAD geometry of the virtual shapes. In this paper, we describe the working principles of the interface by using both absolute and relative approaches to control the position on each single control point on the MEC spline. Then, we describe the methodology that has been implemented, passing from the CAD geometry, linked to VisualNastran in order to maintain the parametric properties of the virtual shape. Then, we present the co-simulation between VisualNastran and MATLAB/Simulink used for achieving this goal and controlling the system and finally, we present the results of the subsequent testing session specifically carried out to evaluate the accuracy and the effectiveness of the mechatronic device.
A Behavioural Model of E-Banking Usage in Italy
Authors: Capece Guendalina , Campisi Domenico
Published: June 2013

E-banking is defined as the automated delivery of new and traditional banking products and services directly to customers through electronic, interactive communication channels. “Pure online” banks are characterized by the absence of physical windows and front-office personnel. Traditional banks are still integrating traditional distribution channels with online ones; the scenario is therefore still evolving over time. Despite the intrinsic potentialities, Italy is far from being a leader in the usage of innovative online instruments in the banking system and will struggle with new innovation waves.

In this paper, we measure the potential effective e-banking usage. Furthermore, we investigate the behaviour of users and adopters, identifying the major causes influencing satisfaction and usage and the impact of these different causes on the intensity of utilization. The analysis is based on a panel of 495 real users, thus allowing the profiling of the Italian adopter to discover the causes of usage and outline strategies for the growth of e-banking services in Italy.
The Role of Experience in the Critical Theory of Technology
Authors: Bendor Roy ,   Philosophy Documentation Center
Published: June 2013

Andrew Feenberg’s critical theory of technology features a sophisticated analysis of the ways by which social forces influence processes of technological design, production and use. While Feenberg is foremostly read as a critical theorist, this essay argues that his call to democratize technology stands on distinct phenomenological grounds. This is based on the way he illustrates the role of experience in subtending potentials for the progressive transformation of the sociotechnical sphere. Against this background, this essay identifies an important shift in the way Feenberg articulates experience, from relating it to lifelong processes of learning and identity-construction (Bildung) to an emphasis on visceral immediacy (Erlebnis). This shift manifests a newfound focus on material, embodied meanings over-against linguistic ones, and results in a considerable tension between Feenberg’s appeal to experiential self-evidence and his critical position toward technology. The discussion of the two modes of experience exemplifies the current that underlies Feenberg’s work, namely the creation of traffic between ontological and ontic accounts of sociotechnical entities, practices and relations.
Resistance Is Futile
Authors: Verbeek Peter-Paul ,   Philosophy Documentation Center
Published: June 2013

Andrew Feenberg’s political philosophy of technology uniquely connects the neo-Marxist tradition with phenomenological approaches to technology. This paper investigates how this connection shapes Feenberg’s analysis of power. Influenced by De Certeau and by classical positions in philosophy of technology, Feenberg focuses on a dialectical model of oppression versus liberation. A hermeneutic reading of power, though, inspired by the late Foucault, does not conceptualize power relations as external threats, but rather as the networks of relations in which subjects are constituted. Such a hermeneutic approach replaces De Certeau’s tactics of resistance with a critical and creative accompaniment of technological developments.
Science, Technology, and the Political
Authors: Goeminne Gert ,   Philosophy Documentation Center
Published: June 2013

In this paper, I elaborate on the very political dimension of epistemology that is opened up by the radical change of focus initiated by constructivism: from science as knowledge to science as practice. In a first step, this brings me to claim that science is political in its own right, thereby drawing on Mouffe and Laclau’s framework of radical democracy and its central notion of antagonism to make explicit what is meant by ‘the political.’ Secondly, I begin to explore what this intrinsic political dimension of science might entail for democratic thought. I do so by connecting my preliminary explorations in the field of science with Andrew Feenberg’s elaborate frame of thought on the democratization of technology. Interestingly, Feenberg is one of the few thinkers who have connected questions of power and ideology, typically treated of within the field of political theory, with a constructivist approach to technological progress. In this sense, this paper can be seen as a first attempt to expand Feenberg’s framework of democratic rationalization from the world of technology to the world of science.
What I Said and What I Should Have Said
Authors: Feenberg Andrew ,   Philosophy Documentation Center
Published: June 2013

In this reply I address problems identified by my critics in my concept of formal bias, my use of phenomenology, the relation between my work and McLuhan’s media theory, and the relation of science to technology.
National, Transnational or Cosmopolitan? Local Immigrant Organisations
Authors: Takle Marianne
Published: June 2013

This article examines how features of theoretical perspectives on transnationalism and cosmopolitanism can be found in categories that immigrant organisations use to describe their own activities. The empirical basis is the written statutes of 133 local membership-based immigrant organisations in Oslo. The article finds that the organisations mainly use national categories and that national belonging is formulated in terms of cultural activities. The use of national categories is, however, combined with many organisations' aims to have transnational ties and activities along with features of cosmopolitan consciousness. Three main patterns emerge. Firstly, while all organisations aim to arrange cultural activities among their members living in Oslo, only a few organisations formulate aims of having a comprehensive transnational practice. Secondly, most organisations aim to combine either various forms of transnationalism and/or features of cosmopolitanism with efforts to integrate their members into Norwegian society, while there is hardly any local identity. Thirdly, the concept of cosmopolitanism is not mentioned by any organisation, although around 40 per cent of them refer to features of cosmopolitanism.
Cosmopolitanism and the Construction of Cultural Models in Contemporary Europe
Authors: O'Mahony Patrick
Published: June 2013

This article outlines a cognitive approach towards analysing and evaluating the process of building a transnational normative culture in Europe through a number of steps. In a first step, employing a number of social theory traditions, a brief outline is offered of European transnationalism as a territorial form. The second step, which is oriented by Habermas's idea of democratic learning processes that bridge national and post-national democratic levels, explores the relationship between democratic communication and normative culture formation on the transnational plane. This leads into the third step that outlines the cognitive mechanisms that affect the formation of post-national democracy. These mechanisms will determine the emergence of transnational normative culture understood as a process of forming suitable cultural models, entailing an ontological, epistemological and methodological shift away from a narrowly conceived normative model. Such a normative model bypasses or minimises the cognitive-communicative mechanisms involved in the dynamic, public construction of meaning and validity. The implications of such a revision of perspectives is further developed in a fourth and concluding step by addressing the kind of transnational deliberative-discursive complex required for the needed cognitive innovation that would in turn make possible appropriate normative innovation informed by a cosmopolitan perspective.
Cosmopolitan Justice and Global Climate Change: Toward Perpetual Peace or War in a Resource-Challenged World?
Authors: Skillington Tracey
Published: June 2013

Can inclinations towards democratic peace be maintained within the international community when competition between states for diminishing natural resource reserves and the threat of military conflict grows ever more intense? Implicit in recent policy discourse on the security implications of climate change is the notion that war, in certain circumstances, is a legitimate response to threat and given the inevitability of shortages amongst many climate-vulnerable states in the future, highly likely. This paper assesses the ‘uncomfortable paradox’ (Beck 2008: 131) that emerges alongside the institutionalisation of a liberal democratic regime that in principle supports global peace under conditions of resource scarcity but in practice, offers legitimation occasionally to its opposite – war. From a critical normative cosmopolitan perspective, the notion that natural resource conflict can be considered ‘just’ or even ‘inevitable’ is objectionable. Ultimately, it is a regressive form of liberalism that allows a war mentality to condition how universal principles of freedom, justice and self-determination are applied to issues of resource distribution in this age of climate adversity when global cooperation is a prerequisite for humanity's long-term survival.
Efficacy of calf:cow ratios for estimating calf production of arctic caribou
Authors: Cameron Raymond D. , Griffith Brad , Parrett Lincoln S. , White Robert G.
Published: June 2013

Caribou (Rangifer tarandus granti) calf:cow ratios (CCR) computed from composition counts obtained on arctic calving grounds are biased estimators of net calf production (NCP, the product of parturition rate and early calf survival) for sexually-mature females. Sexually-immature 2-year-old females, which are indistinguishable from sexually-mature females without calves, are included in the denominator, thereby biasing the calculated ratio low. This underestimate increases with the proportion of 2-year-old females in the population. We estimated the magnitude of this error with deterministic simulations under three scenarios of calf and yearling annual survival (respectively: low, 60 and 70%; medium, 70 and 80%; high, 80 and 90%) for five levels of unbiased NCP: 20, 40, 60, 80, and 100%. We assumed a survival rate of 90% for both 2-year-old and mature females. For each NCP, we computed numbers of 2-year-old females surviving annually and increased the denominator of CCR accordingly. We then calculated a series of hypothetical “observed” CCRs, which stabilized during the last 6 years of the simulations, and documented the degree to which each 6-year mean CCR differed from the corresponding NCP. For the three calf and yearling survival scenarios, proportional underestimates of NCP by CCR ranged 0.046–0.156, 0.058–0.187, and 0.071–0.216, respectively. Unfortunately, because parturition and survival rates are typically variable (i.e., age distribution is unstable), the magnitude of the error is not predictable without substantial supporting information. We recommend maintaining a sufficient sample of known-age radiocollared females in each herd and implementing a regular relocation schedule during the calving period to obtain unbiased estimates of both parturition rate and NCP.
Status of northern mountain caribou (Rangifer tarandus caribou) in Yukon, Canada
Authors: Hegel Troy M. , Russell Kyle
Published: June 2013

Caribou (Rangifer tarandus) are an important ecological, cultural and economic resource in Yukon, Canada. Three caribou ecotypes occur within Yukon: Grant’s (R. t. granti), northern mountain (R. t. caribou), and boreal (R. t. caribou). Northern mountain caribou are classified as a species of special concern under Canada’s Species at Risk Act, and a national management plan for northern mountain caribou was recently completed. Twenty-six northern mountain caribou herds occur at least partially within Yukon, representing approximately 30,000 – 35,000 animals. Active monitoring of Yukon’s northern mountain caribou began in earnest in the early 1980s. To date, over 200 fall composition surveys have been carried out, over 1000 animals have been fitted with radio-collars, and nearly 40 formal population estimates have been completed. Disease and contaminant monitoring of these caribou has indicated relatively low disease prevalence and contaminant loading. Northern mountain caribou are harvested in Yukon, with an average of 230 caribou harvested per year by licensed hunters (1995 – 2012) and an unknown number by First Nation hunters. Future challenges related to caribou management and conservation in Yukon include increasing levels of industrial development primarily through mineral exploration and development, ensuring harvest of these herds is conducted sustainably given the absence of total harvest information, inter-jurisdictional management of shared herds, existing uncertainty surrounding herd distribution and delineation, and dealing with vehicle-related mortality of caribou for certain herds. Overall, the population status (i.e., trend) of eight herds is known, with two increasing, two decreasing, and four stable.
Calf mortality of semi-domesticated reindeer (Rangifer tarandus tarandus) in the Finnish reindeer-herding area
Authors: Nieminen Mauri , Norberg Harri , Maijala Veikko
Published: June 2013

During 1999-2008 calf mortality was studied in six reindeer-herding cooperatives in Northern Finland, where 3942 semi-domesticated reindeer (Rangifer tarandus tarandus) calves were equipped with radio mortality collars. The calves were weighed and earmarked mostly at 2-5 days of age, or at 2-8 weeks of age. Altogether 460 dead radio-collared calves were found from calving in May until winter round-ups in October-January. In northern mountain herding cooperatives, the average mortality of calves varied between 7-12%. On average, 39-54% of calves found dead were attributed to predation. Golden eagles killed 0-3.5% of calves in different years and areas in Ivalo and Käsivarsi cooperatives. Golden eagles were responsible for 33-43% of the cases and 84-93% of all identified predation. Most calves killed by golden eagles were found in July-August and in open areas. Calves killed by golden eagles were significantly (P<0.01) lighter than those not predated. No predation occurred in the Poikajärvi cooperative, but the annual mortality of calves varied between 0-35% in cooperatives near the Russian border. In Oivanki cooperative brown bears killed on average 2% of the radio-collared calves. Most predation (87%) occurred at the end of May and in early June. In the Kallioluoma cooperative, predator-killed calves found comprised 53% and wolf-killed 45%. Predation was 70% of total mortality in the Halla cooperative, and predation by wolf, bear, lynx and wolverine comprised on average 38%, 20%, 9% and 2.3%, respectively. The sex and pelt color did not significantly affect survival of calves. Birth weight of calves killed by bears was significantly (P<0.01) lighter than those not killed, but those calves killed by lynxes were significantly (P<0.05) heavier than that survived. Bears killed calves mainly in May-July, wolves in July-October and lynx in August-December.
Observation of Arctic island barren-ground caribou (Rangifer tarandus groenlandicus) migratory movement delay due to human induced sea-ice breaking
Authors: Dumond Mathieu , Sather Shane , Harmer Rob
Published: June 2013

The seasonal migration of the Dolphin and Union caribou (Rangifer tarandus groenlandicus) herd between Victoria Island and the mainland (Nunavut/Northwest Territories, Canada) relies on the formation of sea-ice that connects the Island to the mainland from late-October to early-June.  During an aerial survey of the Dolphin and Union caribou herd in October 2007 on southern Victoria Island, Nunavut, Canada, we documented the short-term effects of the artificial maintenance of an open water channel in the sea-ice on caribou migratory movements during staging along the coast.
CARMA’s integrative modeling: historical background of modeling caribou and reindeer biology relevant to development of an energy/protein model
Authors: White Robert G. , Daniel Colin J. , Russell Don E.
Published: June 2013

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Moose (Alces alces) population size and density in the Inuvik Region of the Northwest Territories, Canada
Authors: Davison Tracy , Callaghan Kristen
Published: June 2013

Responding to community concerns, the Gwich’in Renewable Resources Board (GRRB) and the Government of the Northwest Territories Department of Environment and Natural Resources (ENR) conducted an aerial moose (Alces alces) survey in the Inuvik region of the Northwest Territories, Canada to estimate moose density and distribution. The survey was flown in March 2011 and a random stratified sample design was used. Local knowledge was incorporated in to the stratification of survey cells. Moose density in survey blocks ranged from 9.66 moose/100 km2 in the Ikhil Pipeline block to 0 in the Peel River block with a coarse overall moose density 2.24 moose/100 km2. Densities found were low but within expected range for the species in this region of North America based on past surveys.
Peary caribou (Rangifer tarandus pearyi) and muskoxen (Ovibos moschatus) on northwest Victoria Island, Northwest Territories
Authors: Davison Tracy , Williams Judy
Published: June 2013

An aerial population survey of Peary caribou (Rangifer tarandus pearyi) and muskoxen (Ovibus moschatus) on Victoria Island, Northwest Territories, was conducted in July 2010. The population estimate of adult Peary caribou was 150 ± 104 (95% Confidence Interval [CI]) was not significantly different than the 2005 estimate of 66 ± 61 (P < 0.05). There was also an estimate of 430 ± 214 (95% CI) adult Dolphin-Union caribou (R. t. groenlandicus x pearyi) in the study area. However, these caribou represent only a small portion of the Dolphin-Union herd.  The population estimate of 11 442 ± 1637 (95% CI) adult muskoxen is not significantly different than the 2005 estimate of 12 062 ± 2156 (P < 0.05).
Modeling energy and protein reserves in support of gestation and lactation: glucose as a limiting metabolite in caribou and reindeer
Authors: White Robert G. , Russell Don E. , Daniel Colin J.
Published: June 2013

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Long-term patterns of abiotic drivers of mosquito activity within summer ranges of Northern Alaska caribou herds (1979–2009)
Authors: Bali Archana , Alexeev Vladimir A. , White Robert G. , Russell Don E. , McGuire A. David , Kofinas Gary P.
Published: June 2013

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Robert John "Bob" Hudson
Authors: Samuel Bill , Stelfox Brad , Foote Lee
Published: June 2013

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Contents
Authors: Wiklund Eva
Published: June 2013

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13th Arctic Ungulate Conference, 22-26 August 2011, Yellowknife, Canada
Authors: Åhman (editor in chief) Birgitta , Wiklund (technical editor) Eva , Hegel (issue editor) Troy
Published: June 2013

The 13th International Arctic Ungulate Conference was held in Yellowknife, Northwest Territories, Canada, from 22-26 August 2011. This biennial conference is the primary venue for meetings of the International Arctic Ungulate Society.  Over 200 delegates attended the conference with representation from Canada, the United States, Norway, Sweden, Greenland, Finland, Russia, and Japan. The theme of the conference was “Challenges of Managing Northern Ungulates”. The goal of the conference organizers was to address the difficulties of managing ungulate populations that are faced with the unpredictable effects of climate change and an ever-increasing human presence on the land. The conference also focussed on the challenges associated with developing recovery actions for declining caribou and reindeer populations that are an integral part of Aboriginal cultures and ways of life.
Creep Properties in TiO2 Nanoparticle Reinforced Aluminum Matrix Composites
Authors: Shin Jaehyuck , Bae Donghyun
Published: June 2013

Creep behaviors of the aluminum composites containing 3 vol% of TiO2 nanoparticles (15 nm in size) are studied at 523 K. In the high stress region, the composites show enhanced creep resistance exhibiting high value of the apparent stress exponent and the high threshold stress, which is determined to be 162 MPa. The true stress exponent of minimum creep strain rate is found to be 5 implying the creep is controlled by lattice diffusion. Negligible stress dependence in the creep rate is found when the applied stresses are <200 MPa, since the creep behavior depends dominantly on the diffusional flows of the matrix that are strictly limited by the nanoparticles.
High Temperature Crystallization of Free‐Standing Anatase TiO2 Nanotube Membranes for High Efficiency Dye‐Sensitized Solar Cells
Authors: Lin Jia , Guo Min , Yip Cho Tung , Lu Wei , Zhang Guoge , Liu Xiaolin , Zhou Limin , Chen Xianfeng , Huang Haitao
Published: June 2013

Despite the one‐dimensional ordering of anodic TiO2 nanotube arrays (TNAs), the electron diffusion towards the substrate in TNA‐based dye‐sensitized solar cells (DSSCs) is comparably slow. The improvement of electron mobility by enhancing TNA crystallinity under high‐temperature annealing, however, is infeasible with the existence of Ti metal substrate. Herein, it is shown that, by high temperature (up to 700 °C) crystallization of high‐quality free‐standing TNA membranes, the TNAs can maintain their structure integrity and phase (anatase) stability as a result of the absence of the nucleation sites and the high quality of the membrane obtained by a self‐detachment method. The electron transport is much faster (≈4 times) in the 700 °C‐annealed TNA membranes than that in the 400 °C‐treated ones for 20 μm‐length nanotubes, which is mainly attributed to the improved crystallinity and reduced electron trap states. In spite of slightly reduced dye loading capacity (decreased by ≈30%) in the 700 °C‐annealed membranes, the superior electron transport leads to a significantly improved efficiency of 7.81% (enhanced by ≈50%). The strategy of manipulating the electron transport dynamics by high temperature treatment on high‐quality TNA membranes may open new route for further improvement in the performances of TNA‐based DSSCs.
Amplified Spontaneous Emission in Pentathienoacene Dioxides by Direct Optical Pump and by Energy Transfer: Correlation with Photophysical Parameters
Authors: Casado Juan , Hernández Víctor , López Navarrete Juan T. , Algarra Manuel , da Silva Filho Demetrio A. , Yamaguchi Shigehiro , Rondão Raquel , Seixas de Melo J. Sérgio , Navarro‐Fuster Víctor , Boj Pedro G. , Díaz‐García María A.
Published: June 2013

Amplified spontaneous emission (ASE) is observed, under optical pump, in polystyrene films doped with two pentathienoacene derivatives functionalised with thienyl‐S,S‐dioxide groups (compounds2and3). The effect of the dioxide groups on the ASE properties is analysed by comparing the performance with that of its corresponding non‐oxidized analogue (1). Films containing either2or3show ASE at 511 and 574 nm, respectively, when excited directly (at 435 nm) on their absorption bands, showing thresholds and linewidths larger than those obtained from films doped with1,pumped at 355 nm. ASE is also observed under excitation at 355 nm, in samples containing1(host) and either2or3(guests), due to energy transfer from host to guest. For the blends with3, the ASE threshold is lower than that obtained when the films are excited directly. Results are interpreted in terms of the photophysical parameters such as absorption capacity, fluorescence efficiency, singlet‐to‐triplet intersystem crossing leading to triplet‐triplet re‐absorptions, bimolecular energy‐transfer efficiency, efficiency of internal conversion process, etc. State‐of‐the‐art quantum chemical calculations are used in the interpretation of the experimental results.
Shrink‐Induced Silica Structures for Far‐field Fluorescence Enhancements
Authors: Lin Sophia , Sharma Himanshu , Khine Michelle
Published: June 2013

Dense multiscale silica (SiO2) micro‐ and nanostructures are fabricated on a pre‐stressed polymer film. This novel SiO2 substrate serves as a robust platform to enhance the fluorescence signal of bound biomolecules. Through a combination of surface concentration, light scattering, and changes in the photophysical properties of the confined dye molecules, dramatic fluorescence signal enhancements (average = 116 times greater than on planar glass) and increased signal‐to‐noise ratio (76:1) are demonstrated with tetramethylrhodamine isothiocyanate (TRITC)‐conjugated streptavidin (STRITC) on SiO2 structures. Enhanced detection sensitivity of STRITC over glass on the SiO2 structures is achieved down to a detection limit of 11 ng mL−1. Such significant fluorescence signal enhancements have importance in practical applications such disease diagnostics and surface sensing.
Gain of employment and depressive symptoms among previously unemployed workers: A longitudinal cohort study in South Korea
Authors: Kim Seung‐Sup , Muntaner Carles , Kim Hyun , Jeon Christie Y. , Perry Melissa J.
Published: June 2013

Background

The goal of this study is to examine the association between gain of employment and depressive symptoms among previously unemployed workers in South Korea.

Methods

Using data from the on‐going Korean Welfare Panel Study, we determined four different employment statuses (i.e., unemployment, part‐time precarious, full‐time precarious, full‐time permanent employment) at follow up (2008 or 2010) among the unemployed at baseline (2007 or 2009) and examined their association with depressive symptoms after excluding the people with depressive symptoms at baseline (N = 308). Depressive symptoms were assessed annually using the 11‐item Center for Epidemiologic Studies Depression Scale.

Results

After adjusting for covariates including health‐related variables, unemployed individuals who gained full‐time permanent employment (RR: 0.38, 95% CI: 0.18, 0.83) and those who gained full‐time precarious employment (RR: 0.26, 95% CI: 0.11, 0.63) were less likely to have depressive symptoms compared to those with persistent unemployment. In a subpopulation analysis conducted after additionally excluding the people with depressive symptoms 1 year before baseline, only the association between gaining full‐time permanent employment and depressive symptoms was significant (RR: 0.27, 95% CI: 0.08, 0.86).

Conclusions

Our findings highlight the benefits of full‐time permanent employment on worker's mental health. Am. J. Ind. Med. 56:1245–1250, 2013. © 2013 Wiley Periodicals, Inc.
Occupation held at the time of asthma symptom development
Authors: Knoeller Gretchen E. , Mazurek Jacek M. , Storey Eileen
Published: June 2013

Background

Examining occupations other than those held when asthma symptoms first developed may not correctly identify occupations with higher risk of asthma onset.

Methods

To determine the occupation held when individuals first developed asthma symptoms, we examined 2010 National Health Interview Survey data for working adults with current asthma.

Results

Overall 37.1% of working adults with current asthma developed asthma while employed. Of these, the highest proportions of individuals identified office and administrative support (13.3%), sales and related (9.4%), and management (8.5%) as the occupation held when asthma first developed; 37.8% had a different current occupation than at asthma onset, and estimates of a change in occupation were highest for those who developed asthma while working in business and financial operations (49.3%), sales and related (48.6%), and healthcare support (43.8%) occupations.

Conclusion

Future population‐based studies should further examine associations between asthma and occupation held at time of asthma onset. Am. J. Ind. Med. 56:1165–1173, 2013. © 2013 Wiley Periodicals, Inc.†
Projections of heavy rainfall over the central United States based on CMIP5 models
Authors: Villarini Gabriele , Scoccimarro Enrico , Gualdi Silvio
Published: June 2013

The central United States is a region for which observational studies have indicated an increase in heavy rainfall. This study uses projections of daily rainfall from 20 state‐of‐the‐art global climate models and one scenario [representative concentration pathway (RCP) 8.5] to examine projected changes in extreme rainfall. Analyses are performed focusing on trends in the 90th and 99th percentiles of the daily rainfall distributions for two periods (2006–2045 and 2046–2085). These results indicate a large increase in extreme rainfall mostly over the northern part of the region, with a much less clear signal over the Great Plains and states along the Gulf of Mexico.
President's page
Authors: Dillon Andrew
Published: June 2013

Editor's Summary

Faced with declining membership numbers, much like other professional organizations, ASIS&T must address the challenge through immediate recruitment efforts and long‐term strategic planning. The number of information science students and the organization's global audience offer strong potential for expanding membership. Dillon urges taking a broad look at membership advantages, considering tangible benefits and especially the intangibles, such as professional identity, community, credentialing and legitimation. Partnering with other associations can promote the organization, and assuming the role as an umbrella organization for scholarly groups in the information sector could provide sustainability more effectively than reliance on membership dues.
Informatics and the future of nursing: Harnessing the power of standardized nursing terminology
Authors: Schwirian Patricia M.
Published: June 2013

Editor's Summary

Rolled into general health services, an invisible part of a hospital room rate, nursing is overdue for its own professional identity. One hallmark of a true profession is universal use of a specialized vocabulary by members. Standardized nursing terminologies provide a consistent basis for communicating the unique contributions of nursing to direct patient care and to research. Nursing has the dubious advantage of having seven recognized term sets serving numerous purposes but undermining the goal of consistency, key to widespread recognition and acceptance. Adoption of a single vocabulary appears doubtful, though two stand out for active support, currency and free availability. Widespread use of a standardized nursing terminology will come with time, consistent use, incorporation into nursing education and reference in professional health care and nursing journals. Cross mappings to important medical terminologies are necessary for interoperability and use in health and nursing informatics research.
Transforming our conversation of information architecture with structure
Authors: Davis Nathaniel
Published: June 2013

Editor's Summary

Since the origin of the concept, information architecture has been viewed as an art and a science, rooted in library science but borrowing from multiple disciplines. Though there are recognized elements, some say it lacks a foundation of consistent internal theory. The central concept of information architecture is structure. Though invisible and often taken for granted, effective structure is the quality that makes websites functional. It rests on navigation, information organization and information relationships and can extend to user experience and spatial representation. Information architecture reflects elements from a number of disciplines but, by aggregating them, is greater than the parts. Advancing information architecture from art to science depends on shared strategies and solutions for website structure.
Using a taxonomy for your database or website: A look behind the scenes
Authors: Hlava Marjorie M.K.
Published: June 2013

Editor's Summary

Peering behind the screen of a database or website reveals the methods and benefits of incorporating a taxonomy. A digital taxonomy file contains terms, term records with details of relationships and a hierarchical structure. The terms are used to categorize content and apply as metanames describing website content items. Digging deeper, the taxonomy terms are stored and associated with a relational database management system, object‐oriented database or XML‐based database system. Taxonomy terms can be presented to the end user in a browsable format along with term record details for additional guidance. Captured in the inverted index of search software, the terms promote findability and search success. Documents with taxonomy terms attached can be accurately retrieved regardless of where they are held, and terms can be repurposed as site labels and points of association between internal content items.
Ahp Cyclodepsipeptides: The Impact of the Ahp Residue on the “Canonical Inhibition” of S1 Serine Proteases
Authors: Stolze Sara C. , Meltzer Michael , Ehrmann Michael , Kaiser Markus
Published: June 2013

S1 serine proteases are by far the largest and most diverse family of proteases encoded in the human genome. Although recent decades have seen an enormous increase in our knowledge, the biological functions of most of these proteases remain to be elucidated. Chemical inhibitors have proven to be versatile tools for studying the functions of proteases, but this approach is hampered by the limited availability of inhibitor scaffold structures with the potential to allow rapid discovery of selective, noncovalent small‐molecule protease inhibitors. The natural product class of Ahp cyclodepsipeptides is an unusual class of small‐molecule canonical inhibitors; the incorporation of protease cleavage sequences into their molecular scaffolds enables the design of specific small‐molecule inhibitors that simultaneously target the S and S′ subsites of the protease through noncovalent mechanisms. Their synthesis is tedious, however, so in this study we have investigated the relevance of the Ahp moiety for achieving potent inhibition. We found that although the Ahp residue plays an important role in inhibition potency, appropriate replacement with β‐hydroxy amino acids results in structurally less complex derivatives that inhibit serine proteases in the low micromolar range.
Salimyxins and Enhygrolides: Antibiotic, Sponge‐Related Metabolites from the Obligate Marine Myxobacterium Enhygromyxa salina
Authors: Felder Stephan , Kehraus Stefan , Neu Edith , Bierbaum Gabriele , Schäberle Till F. , König Gabriele M.
Published: June 2013

Unlike their terrestrial counterparts, marine myxobacteria are hardly investigated for their secondary metabolites. This study describes three new compounds (1–3), named salimyxins and enhygrolides, obtained from the obligate marine myxobacterium Enhygromyxa salina. These are the first natural products obtained from Enhygromyxa species. Their structures were elucidated by spectroscopic analysis, including NMR and CD spectroscopy. Enhygrolides are closely related to the nostoclides, which were initially isolated from a cyanobacterium of the genus Nostoc. The salimyxins, representing structurally most unusual degraded sterols, are close to identical to demethylincisterol from the sponge Homaxinella sp. Salimyxin B and enhygrolide A inhibit the growth of the Gram‐positive bacterium Arthrobacter cristallopoietes (MIC salimyxin B, 8 μg mL−1; enhygrolide A, 4 μg mL−1).