bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical Property Investigation of Soft Materials by Cantilever‐Based Optical Interfacial Force Microscopy
Authors: Kim Byung I. , Boehm Ryan D. 
Published: July 2012

SummaryCantilever‐based optical interfacial force microscopy (COIFM) was applied to the investigation of the mechanical properties of soft materials to avoid the double‐spring effect and snap‐to‐contact problem associated with atomic force microscopy (AFM). When a force was measured as a function of distance between an oxidized silicon probe and the surface of a soft hydrocarbon film, it increases nonlinearly in the lower force region below ∼10 nN, following the Herzian model with the elastic modulus of ∼50 MPa. Above ∼10 nN, it increases linearly with a small oscillatory sawtooth pattern with amplitude 1–2 nN. The pattern suggests the possible existence of the layered structure within the film. When its internal part of the film was exposed to the probe, the force depends on the distance linearly with an adhesive force of −20 nN. This linear dependence suggests that the adhesive internal material behaved like a linear spring with a spring constant of ∼1 N/m. Constant‐force images taken in the repulsive and attractive contact regimes revealed additional features that were not observed in the images taken in the noncontact regime. At some locations, however, contrast inversions were observed between the two contact regimes while the average roughness remained constant. The result suggests that some embedded materials had spring constants different from those of the surrounding material. This study demonstrated that the COIFM is capable of imaging mechanical properties of local structures such as small impurities and domains at the nanometer scale, which is a formidable challenge with conventional AFM methods. SCANNING 35:59‐67, 2013. © 2012 Wiley Periodicals, Inc.
3D Direct Laser Writing of Nano‐ and Microstructured Hierarchical Gecko‐Mimicking Surfaces
Authors: Röhrig Michael , Thiel Michael , Worgull Matthias , Hölscher Hendrik 
Published: July 2012

AbstractApplying 3D direct laser writing, artificial hierarchical gecko‐type structures are designed and fabricated down to nanometer dimensions. In this way, the elastic modulus and the length scale of the gecko's setae are very closely matched. Direct laser writing is a very flexible rapid prototyping method allowing the fabrication of arbitrary nanostructures. Since the parameters of the structures can be easily changed, this technique is perfect for design studies of dry adhesives. Measuring the adhesional forces by atomic force microscopy, the influence of several design parameters like density, aspect ratio, and tip‐shape on dry adhesion performance are systematically examined. In this way, it is revealed that hierarchy is favorable for artificial gecko‐inspired dry adhesives made of stiff materials on the nanometer scale.
Numerical Modeling of Microstructure Evolution During Forging of Crank Shafts
Authors: Milenin Andrzej , Walczyk Wojciech , Pietrzyk Maciej 
Published: July 2012

AbstractApplication of numerical simulations to improve forging technology for crank shafts is the objective of this work. Thermal–mechanical finite element model combined with closed form equations describing microstructure evolution is used. Simulations of grain size changes in several locations in the volume of the forging were performed. Results of simulations allow to evaluate microstructure of the final product.
Adding Collaborative Peer Coaching to Our Teaching Identities
Authors: Jewett Pamela , MacPhee Deborah 
Published: July 2012

AbstractRecent research suggests that personal and institutional constraints often limit the degree to which professional development impacts teaching practice. Darling‐Hammond suggests that one of those constraints is time in schools for collaborative planning. She cites high performing schools in Europe and Asia that have three to four times more collaborative planning time for teachers than schools in the United States, and she suggests that teachers need to discover ways to collaborate to solve problems and improve practice. One way to create the kinds of collaborative teaching communities that Darling‐Hammond proposes is with peer coaching, and this article describes a group of teachers who found ways to work and learn together by adding collaborative peer coaching to their identities as teachers.
Tail homogeneity of invariant measures of multidimensional stochastic recursions in a critical case
Authors: Kolesko Konrad 
Published: July 2012

AbstractWe consider the stochastic recursion $${X_{n+1} = M_{n+1}X_{n} + Q_{n+1}, (n \in \mathbb{N})}$$, where $${Q_n, X_n \in \mathbb{R}^d }$$, M
n
are similarities of the Euclidean space $${ \mathbb{R}^d }$$ and (Q
n
, M
n
) are i.i.d. We study asymptotic properties at infinity of the invariant measure for the Markov chain X
n
under assumption $${\mathbb{E}{[\log|M|]}=0}$$ i.e. in the so called critical case.
On fixed points of a generalized multidimensional affine recursion
Authors: Mirek Mariusz 
Published: July 2012

AbstractLet G be a multiplicative subsemigroup of the general linear group Gl $${(\mathbb{R}^d)}$$ which consists of matrices with positive entries such that every column and every row contains a strictly positive element. Given a G-valued random matrix A, we consider the following generalized multidimensional affine equation$$R\stackrel{\mathcal{D}}{=} \sum_{i=1}^N A_iR_i+B,$$where N ≥ 2 is a fixed natural number, A1, . . . , A
N
are independent copies of $${A, B \in \mathbb{R}^d}$$ is a random vector with positive entries, and R1, . . . , R
N
are independent copies of $${R \in \mathbb{R}^d}$$ , which have also positive entries. Moreover, all of them are mutually independent and $${\stackrel{\mathcal{D}}{=}}$$ stands for the equality in distribution. We will show with the aid of spectral theory developed by Guivarc’h and Le Page (Simplicité de spectres de Lyapounov et propriété d’isolation spectrale pour une famille d’opérateurs de transfert sur l’espace projectif. Random Walks and Geometry, Walter de Gruyter GmbH & Co. KG, Berlin, 2004; On matricial renewal theorems and tails of stationary measures for affine stochastic recursions, Preprint, 2011) and Kesten’s renewal theorem (Kesten in Ann Probab 2:355–386, 1974), that under appropriate conditions, there exists χ > 0 such that $${{\mathbb{P}(\{\langle R, u \rangle > t\})\asymp t^{-\chi}}}$$ , as t → ∞, for every unit vector $${u \in \mathbb{S}^{d-1}}$$ with positive entries.
Natural regeneration of Spanish black pine [Pinus nigra Arn. ssp. salzmannii (Dunal) Franco] at contrasting altitudes in a Mediterranean mountain area
Authors: Lucas‐Borja Manuel E. , Fonseca Teresa Fidalgo , Lousada José Luís , Silva‐Santos Pedro , Garcia Eduardo Martínez , Abellán Manuela Andrés 
Published: July 2012

AbstractInformation on plant seed dispersal, natural loss dynamics of seeds and germination are critical for understanding natural regeneration mechanisms. The aim of this study was to assess the effect of different forest stand densities on seedfall, seed predation, and seedling germination of two populations of the endangered Spanish black Pine forests located at lower (Central population) and higher elevation near the limit of the species’ range (peripheral population) in the Cuenca Mountains of Central Spain. The seed predation and germination experiment also included a nested site preparation treatment. Seed fall varied significantly between 2006 and 2005 or 2007 in both populations. During the only mast year of 2006, higher seedfall was observed at lower elevation and in higher density stands. Predation rates were influenced by the seed crop since predators consumed more than 75 % of seeds in years with lower production and less than 15 % in a mast year. Seed germination is influenced by forest habitat, stand density and soil scalping. For common habitat types, and in a high seed production year, better seed germination rates were observed in medium and dense stands (25–30 and 35–40 m2 ha−1, respectively, in terms of basal area). No statistical difference in seed germination rate was found for Spanish black pine forest at its ecological distribution limit between lower and higher densities (15–20 and 35–40 m2 ha−1, in terms of basal area). In both sites, closed stands with soil scalping exhibited higher germination rates.
Coming to Grips with Evolvability
Authors: Pavlicev Mihaela , Wagner Günter P. 
Published: July 2012

AbstractTo explain the evolution of complex organisms by random mutation, drift, and selection is not a trivial task. This becomes obvious if we imagine an organism in which most genes affect most traits and all mutations are immediately expressed in the phenotype. Most of the mutations will be deleterious. Computer programmers experienced a similar problem when trying to evolve computer programs by introducing random changes to a conventional computer code, realizing that almost all random changes are “lethal.” Everyone who has done any programming knows that conventional computer languages are very brittle! Real organisms are not organized in this way but rather involve mediation between the genes and the phenotypic traits, namely development, also sometimes called the genotype–phenotype map. This map of genetic effects is structured in a way that enables evolvability, that is, enhances the probability that mutations will improve the performance of the organism. Here we outline two properties of organismal development, namely modularity and robustness. Modularity refers to the situation in which genes affect a restricted number of functionally related phenotypic characters. Robustness describes a situation in which cryptic mutations can accumulate without effect on fitness but can become visible to selection in a new environment or genetic background. We discuss recent empirical evidence in support of both phenomena and their effect on evolvability and also briefly address their evolution.
Kinematic analysis of leg alignment during conventional versus navigated total knee arthroplasty: Initial results of a prospective study
Authors: Chang Chih‐Wei , Chang Chih‐Hang , Yang Chyun‐Yu , Lai Kuo‐An , Lin Cheng‐Li , Lin Chii‐Jeng 
Published: July 2012

AbstractCurrent kinematic navigation systems provide real‐time spatial analyses of leg alignments during total knee arthroplasty (TKA) instead of delayed radiographic verification after surgery. A prospective study was conducted to investigate leg alignments of TKAs that underwent different surgical guidance [intramedullary (IM) jig‐based vs. navigation‐assisted] using a kinematic navigation system. Since May 2007, patients admitted for primary TKA were considered for inclusion. Within 6 months, 38 sets of intraoperative analyses on the operated legs have been performed. Excluding seven unreliable data sets, 15 conventional IM jig‐based TKAs and 16 navigation‐assisted TKAs were available. The leg alignments in maximum knee extension were retrieved for comparison. Although similar final coronal alignments were accurately achieved in both groups (0.21 valgus in the IM group vs. 0.17 valgus in the NA group, p = 0.993), a more flexed sagittal axis was constructed with conventional IM jigs (1.93 flexion in the IM group vs. 0.58 extension in the NA group, p < 0.05). The study suggests that comparable coronal precision could be achieved with conventional IM jigs by trained surgeons, although computer‐assisted navigation is a documented method to restore accurate alignment. Different sagittal alignments observed in this study indicate the inherent discrepancy between different surgical guides as well as their according concepts.
Systematic review of neuropathic component in persistent post-surgical pain
Authors: Haroutiunian S. , Nikolajsen L. , Finnerup N.B. , Jensen T.S. 
Published: July 2012

Abstract

Background/aim
The aim of the current study was to assess the neuropathic component of persistent post-surgical pain (PPSP) following eleven types of surgery.

Methods
We performed a systematic PubMed, CENTRAL and EMBASE search to identify studies on PPSP following (i) thoracic surgery, (ii) breast surgery, (iii) groin hernia repair, (iv) prostatectomy, (v) major abdominal surgery, (vi) gynecologic surgery, (vii) iliac crest bone harvest, (viii) total hip arthroplasty (THA) or knee arthroplasty (TKA), (ix) varicose vein stripping or ablation, (x) mandibular sagittal split osteotomy and (xi) donor nephrectomy, and assessed the prevalence of Probable/Definite neuropathic pain using the recently published neuropathic pain probability grading criteria [1].

Results
We included 291 relevant papers. Surgeries performed in the thoracic/breast area resulted in similarly high median PPSP prevalence of about 30–35%; bone and joint surgeries resulted in similar PPSP prevalence of about 20%; and surgeries on visceral organs resulted in lower PPSP prevalence of 10–14%. The reported ranges of PPSP prevalence were very wide, between 0 and 91%. The prevalence of Probable/Definite neuropathic pain among patients with PPSP was about 65% after thoracic and breast surgeries, about 32% after groin hernia repair and gynecologic surgery, and between 9 and 16% after bone and joint surgeries such as iliac crest bone harvest and THA/TKA. In varicose vein surgeries and mandibular sagittal split osteotomies more research is needed to investigate the contribution of neuropathic pain mechanisms.

Conclusion
PPSP after different surgeries is reported to be common and often neuropathic. This systematic review of the literature showed that reported PPSP prevalences range widely among studies, and only a minority of studies used methodology that enabled the estimation of Probable/Definite neuropathic pain prevalence.
The 1.5-ka varved record of Lake Montcortès (southern Pyrenees, NE Spain)
Authors: Corella Juan Pablo , Brauer Achim , Mangili Clara , Rull Valentí , Vegas‐Vilarrúbia Teresa , Morellón Mario , Valero‐Garcés Blas L. 
Published: July 2012

AbstractThe karstic Lake Montcortès sedimentary sequence spanning the last 1548 yr constitutes the first continuous, high-resolution, multi-proxy varved record in northern Spain. Sediments consist of biogenic varves composed of calcite, organic matter and detrital laminae and turbidite layers. Calcite layer thickness and internal sub-layering indicate changes in water temperature and seasonality whereas the frequency of detrital layers reflects rainfall variability. Higher temperatures occurred in Lake Montcortès in AD 555–738, 825–875, 1010–1322 and 1874–present. Lower temperatures and prolonged winter conditions were recorded in AD 1446–1598, 1663–1711 and 1759–1819. Extreme and multiple precipitation events dominated in AD 571–593, 848–922, 987–1086, 1168–1196, 1217–1249, 1444–1457, 1728–1741 and 1840–1875, indicating complex hydrological variability in NE Spain since AD 463. The sedimentary record of Lake Montcortès reveals a short-term relation between rainfall variability and the detrital influx, pronounced during extended periods of reduced anthropogenic influences. In pre-industrial times, during warm climate episodes, population and land use increased in the area. After the onset of the industrialization, the relationship between climate and human activities decoupled and population dynamics and landscape modifications were therefore mostly determined by socio‐economic factors.
Flow of fluids with pressure- and shear-dependent viscosity down an inclined plane
Authors: Rajagopal K. R. , Saccomandi G. , Vergori L. 
Published: July 2012

AbstractIn this paper we consider a fluid whose viscosity depends on both the mean normal stress and the shear rate flowing down an inclined plane. Such flows have relevance to geophysical flows. In order to make the problem amenable to analysis, we consider a generalization of the lubrication approximation for the flows of such fluids based on the development of the generalization of the Reynolds equation for such flows. This allows us to obtain analytical solutions to the problem of propagation of waves in a fluid flowing down an inclined plane. We find that the dependence of the viscosity on the pressure can increase the breaking time by an order of magnitude or more than that for the classical Newtonian fluid. In the viscous regime, we find both upslope and downslope travelling wave solutions, and these solutions are quantitatively and qualitatively different from the classical Newtonian solutions.
GENETICS OF POPULATION EXCHANGE ALONG THE HISTORICAL PORTUGUESE–SPANISH BORDER
Authors: ROMÁN-BUSTO J. , TASSO M. , CARAVELLO G. , FUSTER V. , ZULUAGA P. 
Published: July 2012

SummaryThe present analysis compares the distribution of surnames by means of spatial autocorrelation analysis in the Spain–Portugal border region. The Spanish National Institute of Statistics provides a database of surnames of residents in the western Spanish provinces of Zamora, Salamanca, Cáceres, Badajoz and Huelva. The Spanish and Portuguese patterns of surname distribution were established according to various geographic axes. The results obtained show a low diversity of surnames in this region – especially in the centre – which can be explained by the absence of any major geographic barriers, with the exception of the mountain ranges between hydrographic basins, and by the presence of traditional roads that have existed since Roman times. The latter have resulted in a constant migratory flow over short–median distances, which, as can be deduced from the surnames, fits two north/south territorial axes running parallel to the border between Spain and Portugal. The distribution patterns of Portuguese and Spanish surnames differ with regard to their frequencies in the five provinces studied, which can be attributed to their respective historical, economic and social conditions. It is concluded that the border delimiting these two countries has affected the migratory flow, thereby conditioning the demographic and genetic structure of the western Spanish regions.
Attending to Time and Place in Rousseau's Legislative Art
Authors: Schaeffer Denise 
Published: July 2012

AbstractIn his Plan for a Constitution for Corsica, Rousseau recommends a series of institutional arrangements and psychological incentives designed to generate certain salutary opinions and behaviors on the part of the citizens. However, he also indicates in several ways that it is not only impossible to control such outcomes absolutely or permanently, but also undesirable insofar as a static people tends to be a languorous people. This essay argues that the model of citizenship that emerges in Corsica is more dynamic and less thoroughly choreographed than is often recognized. Rousseau suggests that what it takes to attach citizens to the collective good over the long term requires not only a specific form of socialization, but also that the people are capable, to some degree, of transcending their socialization. The goal of Rousseau's legislative art is not to form a people that can remain on “autopilot,” but rather to cultivate a form of reflection and judgment that is rooted in and animated by healthy attachments and proper conditioning of the passions. The puzzle becomes the relationship between these two sides of the legislative art.
How Academics Can Help People Make Better Decisions Concerning Global Poverty
Authors: Horton Keith 
Published: July 2012

One relatively straightforward way in which academics could have a positive impact on global poverty is by putting people in a position to make better decisions about issues relevant to such poverty. Academics could do this by conducting appropriate kinds of research on those issues, and sharing what they have learned in accessible ways.But aren't academics already doing this? In the case of many of those issues, I think the appropriate answer would be “Yes, to some extent, but they could do so much better.” In this article, I first discuss the academic research relevant to one important decision about an issue concerning global poverty. I argue that this research has been seriously deficient both in terms of quality and of quantity. Building on this discussion, I then formulate two questions that can be applied to any such decision, answers to which would indicate the quality of the input academics are currently providing. In cases where that input is deficient, and the decision in question an important one, I suggest that academics organise themselves in ways that will improve that input. I finish by briefly discussing how Academics Stand Against Poverty might help them do so.
The African wintering distribution and ecology of the Corncrake Crex crex
Authors: WALTHER BRUNO A. , BARRY TAYLOR P. , SCHÄFFER NORBERT , ROBINSON SUE , JIGUET FREDERIC 
Published: July 2012

SummaryThe Corncrake Crex crex breeds in the Palearctic but overwinters in central and southern Africa. While some information had previously been gathered about the Corncrake’s African wintering distribution, we here analyse a much more comprehensive database of 1,284 records based on a five-year desk study completed in January 2011 and use those records selected for spatio-temporal accuracy to build a continental distribution model. Our model was based mostly on climatic variables and predicts a high suitability for most eastern Africa countries south of the equator, but none of the western African countries with the exception of Angola and Namibia. Both the actual number of records as well as the distribution model thus indicates that the vast majority of Corncrakes migrate through and overwinter in the eastern parts of Africa. Because large parts of Angola, Mozambique, north-eastern Namibia, and Tanzania are predicted as suitable but have yielded very few actual records so far, they should be targeted for future field work. A very small number of Corncrakes may oversummer in Africa but such individuals are possibly unable to migrate due to sickness or injury, or may be first-year birds that are not ready to breed. An analysis of habitat and population density data indicates that, within the continental distribution, Corncrakes are mostly concentrated within grass-dominated habitats, mirroring their habitat preferences in the breeding areas. Corncrakes reach their wintering distribution mostly through an eastern migration route, but some individuals or subpopulations from the Western breeding population also use a western migration route. We also document the food choices, weights, and causes of injury and death within Africa. Because habitat conversion is accelerating all across Africa, we recommend constant monitoring of habitat availability and population densities within the Corncrake’s wintering distribution.
Welfare costs and benefits of non-tariff measures in trade: a conceptual framework and application
Authors: BEGHIN JOHN , DISDIER ANNE-CÉLIA , MARETTE STÉPHAN , VAN TONGEREN FRANK 
Published: July 2012

AbstractThis paper provides a systematic welfare-based approach to analyze the impact of non-tariff measures (NTMs) on trade and welfare in the presence of market imperfections. It focuses on standard-like measures such as technical barriers and sanitary and phytosanitary regulations. The approach overcomes the shortcomings of the mainstream approach based on the analysis of foregone trade caused by trade costs. The latter ignores market imperfections, and welfare is found to increases when NTMs are reduced and trade expands. We explain how to account for external effects and market failures in trade-focused welfare analysis, leading to a more balanced overall assessment of measures despite a potential reduction of trade flows. The relationships between trade, welfare, and NTMs are complex, and generalizations are best avoided. Very often, the optimum NTM is not the absence of regulation. An application to shrimp trade illustrates the feasibility of the proposed approach. The illustration shows that the reinforcement of a food safety standard can be socially preferable to the status-quo situation, both domestically and internationally.