bluuebunny/crossref_metadata_2025 huggingface dataset:
Scenes from the Global Village
Authors: Bithell Caroline
Published: October 2014

Chapter 8 pursues the theme of community in relation to the notion of the global village. The Unicorn Natural Voice Camp (held in England) and a set of overseas singing tours organised by Village Harmony (in Corsica, Bosnia, and Georgia) serve as detailed case studies. The analysis is framed by perspectives derived from the critical literature on travel and tourism. It explores the dynamics of “being there” for tour participants and the symbolic meanings that may be attached to their presence by the host community, and reveals how transnational networks contribute to the sustainability of local communities, and vice versa. The chapter ends by revisiting questions of identity in the contemporary world, together with ideas about how the performing arts offer themselves as a prime site for experimenting with new ways of living and being.
The Voice of the Future
Authors: Bithell Caroline
Published: October 2014

Chapter 9 takes the form of an extended conclusion that draws together the various threads that have been woven through the book. First, it reviews a set of key themes and concepts that have reappeared in different guises: finding a voice, participation, performance, community, networks, journeys, liberation, transcendence, empowerment, crossing boundaries, opening doors, liminality, communitas, transformation, conviviality, and collective joy. It then elaborates on the ways in which certain fallacies, misconceptions, and assumptions have been challenged or reframed in the worlds the reader has entered in the course of his or her journey through the book. The chapter ends by reflecting on the broader impact of the trends and initiatives described and their potential to contribute to a substantial reconfiguring of ideas about vocal identity and musical sounds and values and meanings.
Phase integral approximations
Authors: Child M. S.
Published: October 2014

Phase integral approximations express the quantum wavefunction in terms of the classical action integral, S(x)=∫p(x)dx.The main aim of the chapter is to highlight the strengths and weaknesses of the standard JWKB expansion for S(x) in powers of Planck’s constant. Remarkably, the catastrophic weakness at a classical turning point is shown to be eliminated by use of an alternative Airy uniform approximation, which depends only on the primitive JWKB phase information. The discussion brings out an important primitive semiclassical connection between the JWKB function and the stationary phase approximation. The analysis also leads naturally to Maslov phase contributions to the Bohr–Sommerfeld quantization condition and to an equivalent formula for the semiclassical phase shift. An alternative type of general uniform theory, again dependent on the primitive JWKB information, is extended to a family of multi-turning-point problems. Finally, higher-order corrections to the JWKB approximation are derived and tested against the pathological quartic oscillator problem.
Quantization
Authors: Child M. S.
Published: October 2014

The quantization formula, ∮p(x)dx=(n+δ)h is shown to include a Maslov index, δ , dependent on the distribution of turning points and singularities. A related argument explains why singularities in the angular momentum equation require the Langer substitution ℓ(ℓ+1)→(ℓ+1/2) The subsequent sections show how semiclassical connection formulae may be used to stitch JWKB fragments of the wavefunction together in a variety of tunnelling and curve–crossing situations. Diagrammatic representations of the connection formulae are used to illustrate the quantization of double minimum and restricted rotation problems. Applications are also given to the widths of shape resonance widths and the rates of curve-crossing predissociation. The latter are particularly interesting in showing rapid fluctuations from one quasi-bound level to another.
Reactive scattering
Authors: Child M. S.
Published: October 2014

Three topics in reactive scattering are discussed. The first concerns nearside–farside theory, taken from the nuclear physics literature, for the interpretation of reactive differential cross-sections. The second section describes recent progress in the prediction and interpretation of geometric phase effects, including an interesting symmetry interpretation in the extended group appropriate to double encirclement of the conical intersection. The predictions are confirmed by comparison between classical trajectory studies of geometric phase changes to the differential cross-section. The final section covers the instanton theory of low temperature chemical rate constants. Its role as a generalized transition state is outlined and connections between the semiclassical theory and the superficially distinct ring polymer theory are indicated.
From Conflict to Companionship
Authors: Arnett Jeffrey Jensen
Published: October 2014

This chapter examines the many facets of emerging adults’ relationships with their parents. First, the overall outline of relations with parents in emerging adulthood is described, showing a remarkably positive picture. Then the changes that take place when emerging adults move out of their parents’ household are examined, as well as the experiences of emerging adults who move back in again and those who remain at home. Next comes a look at the shift that often takes place in emerging adulthood from a parent-child relationship to a new relationship as friends and companions. Finally, there is a complex rendering of the enduring repercussions of parents’ divorce and remarriage—how emerging adults recall these events and how they believe they have been shaped by them, in both positive and negative ways.
Work
Authors: Arnett Jeffrey Jensen
Published: October 2014

In this chapter the focus is on how emerging adults go about searching for satisfying work. It is emphasized that the ideal for emerging adults is finding a job that clicks with their developing identity. However, relatively few pursue this ideal in a systematic way, and many take a job of any kind in order to pay their bills. Next is a look at variations in being ready to make a long-term decision about work. Unemployment prevalence among young people is discussed, including the basis for it. This is followed by a section describing influences on job choice, especially the complex influences parents can have, and a section describing the dreams that some emerging adults have for an alluring and sometimes elusive work ideal. The chapter ends with a section on work and identity that attempts to integrate the previous material into a theoretical framework.
Sources of Meaning
Authors: Arnett Jeffrey Jensen
Published: October 2014

This chapter examines some of the religious beliefs and values that are part of the worldviews of emerging adults. The section on religious beliefs examines both the diversity of emerging adults’ beliefs and their common determination to think for themselves with regard to religious issues. There is also an examination of the ways that emerging adults think about the possibility of an afterlife. Here, too, their views are diverse, and often expressed with mordant humor. In the section on values the focus is on emerging adults’ responses to two questions concerning their values for their own lives and the values they wish to pass on to the next generation. Together, these two questions provide an outline of the extent to which emerging adults’ values reflect individualism and collectivism. It is concluded that most emerging adults balance an Ethic of Autonomy, reflecting individualism, with an Ethic of Community, reflecting collectivism.
Wrong Turns and Dead Ends
Authors: Arnett Jeffrey Jensen
Published: October 2014

Some kinds of problems appear to be more prevalent in emerging adulthood than in any subsequent adult life stage. This chapter first examines rates and sources of externalizing problems (including automobile accidents, crime, and substance abuse) and internalizing problems (including depression, anxiety, and eating disorders). Then the theory of emerging adulthood is applied to understanding why some of these problems are especially prevalent in this life stage, using the five features of emerging adulthood as a framework. Finally, trends in the past two decades are examined in rates of some externalizing problems, and possible reasons for those trends. Most trends are positive, especially in automobile accidents and crime, but certain kinds of substance use have increased.
Sometimes Goodbye Is a Second Chance
Authors: Arnett Jeffrey Jensen
Published: October 2014

In some ways, reaching emerging adulthood offers even more opportunity for persons from a difficult background than for those from a privileged background. Specifically, they become capable of leaving a troublesome family environment and living on their own, potentially transforming their lives and setting them on a different path from their parents. Consequently, emerging adulthood is arguably the period of the life course when the possibility for dramatic change is greatest. This chapter illustrates this aspect of emerging adulthood theory by examining the lives of four emerging adults whose lives defy the assumption that one’s early years permanently decide the path one will follow in the future. All of them experienced terrible events or circumstances in childhood, all of them had lives that were in disarray by adolescence, and all of them transformed themselves in emerging adulthood and turned their lives in a dramatically different direction, toward health and happiness.
KmerStream: streaming algorithms for
k
-mer abundance estimation
Authors: Melsted Páll , Halldórsson Bjarni V.
Published: October 2014

Motivation: Several applications in bioinformatics, such as genome assemblers and error corrections methods, rely on counting and keeping track of k -mers (substrings of length k ). Histograms of k -mer frequencies can give valuable insight into the underlying distribution and indicate the error rate and genome size sampled in the sequencing experiment.

Results: We present KmerStream, a streaming algorithm for estimating the number of distinct k -mers present in high-throughput sequencing data. The algorithm runs in time linear in the size of the input and the space requirement are logarithmic in the size of the input. We derive a simple model that allows us to estimate the error rate of the sequencing experiment, as well as the genome size, using only the aggregate statistics reported by KmerStream.

As an application we show how KmerStream can be used to compute the error rate of a DNA sequencing experiment. We run KmerStream on a set of 2656 whole genome sequenced individuals and compare the error rate to quality values reported by the sequencing equipment. We discover that while the quality values alone are largely reliable as a predictor of error rate, there is considerable variability in the error rates between sequencing runs, even when accounting for reported quality values.

Availability and implementation: The tool KmerStream is written in C++ and is released under a GPL license. It is freely available at https://github.com/pmelsted/KmerStream

Supplementary information:  Supplementary data are available at Bioinformatics online.

Contact:  pmelsted@hi.is or Bjarni.Halldorsson@decode.is .
Evolution of magnetic field inclination in a forming penumbra
Authors: Jurčák Jan , Bello González Nazaret , Schlichenmaier Rolf , Rezaei Reza
Published: October 2014

As a sunspot penumbra forms, the magnetic field vector at the outer boundary of the protospot undergoes a transformation. We study the changes of the magnetic field vector at this boundary as a penumbral segment forms. We analyze a set of spectropolarimetric maps covering 2 hr during the formation of a sunspot in NOAA 11024. The data were recorded with the GFPI instrument attached to the German VTT. We observe a stationary umbra/quiet Sun boundary, where the magnetic field becomes more horizontal with time. The magnetic field inclination increases by 5°, reaching a maximum value of about 59°. The maximum inclination coincides with the onset of filament formation. In time, the penumbra filaments become longer and the penumbral bright grains protrude into the umbra, where the magnetic field is stronger and more vertical. Consequently, we observe a decrease in the magnetic field inclination at the boundary as the penumbra grows. In summary, in order to initiate the formation of the penumbra, the magnetic field at the umbral (protospot) boundary becomes more inclined. As the penumbra grows, the umbra/penumbra boundary migrates inwards, and at this boundary the magnetic field turns more vertical again, while it remains inclined in the outer penumbra.
Long-term evolution of large-scale magnetic fields in rotating stratified convection
Authors: Masada Youhei , Sano Takayoshi
Published: October 2014

Convective dynamo simulations are performed in local Cartesian geometry. We report the first successful simulation of a large-scale oscillatory dynamo in rigidly rotating convection without stably stratified layers. A key requirement for exciting the large-scale dynamo is a sufficiently long integration time comparable to the ohmic diffusion time. By comparing two models with and without stably stratified layers, their effect on the large-scale dynamo is also studied. The spatiotemporal evolution of the large-scale magnetic field is similar in both models. However, it is intriguing that the magnetic cycle is much shorter in the model without the stable layer than with the stable layer. This suggests that the stable layer impedes the cyclic variations of the large-scale magnetic field.
Centre-to-limb spectro-polarimetric diagnostics of simulated solar photospheric magneto-convection: Signatures of photospheric Alfvén waves
Authors: Shelyag Sergiy , Przybylski Damien
Published: October 2014

Using numerical simulations of the magnetized solar photosphere carried out with the radiative magneto-hydrodynamic code, MURaM, and detailed spectro-polarimetric diagnostics of the simulated photospheric 6302 Å Fe i line, spectro-polarimetric signatures of Alfvén waves in magnetized intergranular lanes of the simulated solar photosphere were analysed at different positions at the solar disk. The torsional Alfvén waves in the intergranular lanes are horizontal plasma motions, which do not have a thermal perturbation counterpart. We find signatures of Alfvén waves as small-scale line profile Doppler shifts and Stokes-V area asymmetry enhancements in the simulated off-disk centre observations. These photospheric features disappear when the simulated observations are degraded with a telescope point spread function (PSF) similar to the one of Hinode. We analyse the possibilities for direct observations and confirmation of Alfvén wave presence in the solar photosphere.
Adaptive nowcasting of influenza outbreaks using
Google
searches
Authors: Preis Tobias , Moat Helen Susannah
Published: October 2014

Seasonal influenza outbreaks and pandemics of new strains of the influenza virus affect humans around the globe. However, traditional systems for measuring the spread of flu infections deliver results with one or two weeks delay. Recent research suggests that data on queries made to the search engine
Google
can be used to address this problem, providing real-time estimates of levels of influenza-like illness in a population. Others have however argued that equally good estimates of current flu levels can be forecast using historic flu measurements. Here, we build dynamic ‘nowcasting’ models; in other words, forecasting models that estimate current levels of influenza, before the release of official data one week later. We find that when using
Google Flu Trends
data in combination with historic flu levels, the mean absolute error (MAE) of in-sample ‘nowcasts’ can be significantly reduced by 14.4%, compared with a baseline model that uses historic data on flu levels only. We further demonstrate that the MAE of out-of-sample nowcasts can also be significantly reduced by between 16.0% and 52.7%, depending on the length of the sliding training interval. We conclude that, using adaptive models,
Google Flu Trends
data can indeed be used to improve real-time influenza monitoring, even when official reports of flu infections are available with only one week's delay.
Leadership practices influencing stakeholder satisfaction in Thai SMEs
Authors: Suriyankietkaew Suparak , Avery Gayle C.
Published: October 2014

Purpose

– The purpose of this paper is to investigate the leadership and management practices that positively affect stakeholder satisfaction, an under-studied area important for both academic researchers and leaders. Relationships between 23 leadership and management practices and overall stakeholder satisfaction (OSS) were examined.

Design/methodology/approach

– Avery and Bergsteiner ' s (2010, 2011a) sustainable leadership (SL) model provided the theoretical framework for a cross-sectional survey research design used to gather empirical data from 439 managers of small- and medium-sized enterprises (SMEs) in Thailand.

Findings

– Results show all SL practices except financial market orientation were significantly related to OSS, and the more an organisation adopts significant SL practices, the higher the OSS is likely to be. The particular SL practices that positively predicted enhanced OSS were amicable labour relations, staff retention, strong and shared vision, strategic and systemic innovation, and high staff engagement and quality.

Research limitations/implications

– Future research should further examine relationships between SL practices and a range of organisational performance outcomes in different contexts, as well as the relationship between SL practices and sustainable human resource management (SHRM), and between SHRM and stakeholder satisfaction.

Practical implications

– The findings provide guidance on which SL practices to adopt for managers of SMEs in Thailand and possibly in other countries, who wish to improve their stakeholder satisfaction and sustain their business success.

Social implications

– Policy makers may gain insights into practices that drive performance in SMEs, a strong force in many economies.

Originality/value

– This study extends current knowledge of leadership and management practices that positively predict enhanced stakeholder satisfaction, an area in which empirical evidence has to date been largely lacking.
Sustainability: the missing element in performance management
Authors: Maley Jane
Published: October 2014

Purpose

– The performance management process has typically focussed on the achievement of short-term financial goals and ignored longer-term broader goals such human, social and environmental goals. In an attempt to overcome this limitation, the purpose of this paper is to explore the benefits of a broader approach to performance management that offers a balance of organizational financial goals with positive human and social outcomes. Specifically, the paper reviews the adoption of a sustainable human resources (HR) approach to performance management.

Design/methodology/approach

– This conceptual study considers the effect of the firm ' s short-term financial focus on the multinational corporation ' s (MNC ' s) performance management process.

Findings

– The study finds a performance management process with a short-term financial ultimately ignores the developmental needs of the employee.

Research limitations/implications

– In future studies that include empirical data and in particular longitudinal data should be considered so as to examine changes to employee performance management behaviors due to the implementation of a sustainable approach to performance management.

Social implications

– The study shows that the adoption of a sustainable HR approach to performance management incorporates a balance of organizational financial goals with positive human and social outcome, both of which are necessary to achieve and sustain superior long-term organizational performance.

Originality/value

– The study suggests that when a MNC uses a sustainable HR approach, the performance management process is highly likely to make a stronger contribution to MNC effectiveness. The outcome is a balance between organizational financial outcomes and provision for employees. Performance managing people in organizations in a sustainable way, could prove to be strong source of competitive advantage. Hence, this study makes a central contribution to HR scholarship.
Finding a crack's position and its parameters on the basis of non-destructive testing, using eddy currents
Authors: Jesenik Marko , Hamler Anton , Beković Miloš , Trlep Mladen
Published: October 2014

Purpose

– The purpose of this paper is to find the geometry of a crack within a conductive plate and its parameters, on the basis of non-destructive testing, using eddy currents. The input data represents the measured values of magnetic flux density within the centre of the excitation coil.

Design/methodology/approach

– The position of a crack can be determined by taking into consideration any change in the magnetic flux density between the measured points. The depth and width are determined through the use of a finite element model.

Findings

– These calculations are the basis for determining a function that explains how magnetic flux density changes if the depth or width has changed. Jacobi's matrix is calculated using the determined functions’ analytical derivatives.

Originality/value

– After wards, through the Newton-Raphson iterative procedure using the finite element method calculation results, the crack-depth and width can be obtained, this being one of the objectives in this paper. The suitability of the presented method was verified by the experimental example.
Lorentz force eddy current testing: a novel NDE-technique
Authors: Brauer Hartmut , Porzig Konstantin , Mengelkamp Judith , Carlstedt Matthias , Ziolkowski Marek , Toepfer Hannes
Published: October 2014

Purpose

– The purpose of this paper is to present a novel electromagnetic non-destructive evaluation technique, so called Lorentz force eddy current testing (LET). This method can be applied for the detection and reconstruction of defects lying deep inside a non-magnetic conducting material.

Design/methodology/approach

– In this paper the technique is described in general as well as its experimental realization. Besides that, numerical simulations are performed and compared to experimental data. Using the output data of measurements and simulations, an inverse calculation is performed in order to reconstruct the geometry of a defect by means of sophisticated optimization algorithms.

Findings

– The results show that measurement data and numerical simulations are in a good agreement. The applied inverse calculation methods allow to reconstruct the dimensions of the defect in a suitable accuracy.

Originality/value

– LET overcomes the frequency dependent skin-depth of traditional eddy current testing due to the use of permanent magnets and low to moderate magnetic Reynolds numbers (0.1-1). This facilitates the possibility to detect subsurface defects in conductive materials.
Solution of skin-effect problems by means of the hybrid SDBCI method
Authors: Aiello Giovanni , Alfonzetti Salvatore , Salerno Nunzio
Published: October 2014

Purpose

– The purpose of this paper is to present a modified version of the hybrid Finite Element Method-Dirichlet Boundary Condition Iteration method for the solution of open-boundary skin effect problems.

Design/methodology/approach

– The modification consists of overlapping the truncation and the integration boundaries of the standard method, so that the integral equation becomes singular as in the well-known Finite Element Method-Boundary Element Method (FEM-BEM) method. The new method is called FEM-SDBCI. Assuming an unknown Dirichlet condition on the truncation boundary, the global algebraic system is constituted by the sparse FEM equations and by the dense integral equations, in which singularities arise. Analytical formulas are provided to compute these singular integrals. The global system is solved by means of a Generalized Minimal Residual iterative procedure.

Findings

– The proposed method leads to slightly less accurate numerical results than FEM-BEM, but the latter requires much more computing time.

Practical implications

– Then FEM-SDBCI appears more appropriate than FEM-BEM for applications which require a shorter computing time, for example in the stochastic optimization of electromagnetic devices.

Originality/value

– Note that FEM-SDBCI assumes a Dirichlet condition on the truncation boundary, whereas FEM-BEM assumes a Neumann one.
Psychological health and discrimination experience among graduate students: findings from the Stress Coping Obstruction Prevention & Education (SCOPE) Study
Authors: L. Wilkinson Larrell , Kerr Jelani , Smith Temple , Salaam Muhammad , W. Flournoy Minnjuan , Magwood Jametta , Williams Edith , Glover Saundra
Published: October 2014

Purpose

– African-Americans historically report greater exposure to discrimination and also experience unfavorable outcomes associated with physical health, poverty concentration, residential segregation, and poorer education. The effects of discrimination are particularly harmful on mental health as discriminatory experiences contribute significantly to diminished mental health status and psychological distress. African-Americans pursuing graduate education may experience additional stressors, increasing the risk for poorer mental health. The purpose of this paper is to examine the association of psychological health and discrimination experiences among black and white graduate students at a southeastern university.

Design/methodology/approach

– Participants were 505 graduate students at a predominantly white southeastern institution. Researchers collected data via self-administered online and paper questionnaires during the spring 2010 semester. Graduate students were asked questions pertaining to individual demographics, discrimination, and psychosocial concerns.

Findings

– Approximately 15 percent of the graduate students reported psychological distress. Additionally, black graduate students reported significantly higher levels of day-to-day and lifetime discrimination when compared to white graduate students. In addition to the proportions of psychological distress differing by race, African-American graduate students reported better psychological well-being when exposed to both day-to-day and lifetime discrimination than whites with similar exposure.

Practical implications

– Resilience factors and coping strategies should be examined further among African-American graduate students for greater understanding. Moreover, it is important to develop applications to improve mental health outcomes for all graduate students.

Originality/value

– This is one of the few studies to focus on the mental health and discrimination experiences among a graduate student population. The sample is drawn from the southeastern USA where there are long vestiges of discrimination and a sizable sampling of African-Americans who live in the USA.
Repairing trust in an e-commerce and security context: an agent-based modeling approach
Authors: Choi Jae , Nazareth Derek L.
Published: October 2014

Purpose

– The aim of this paper is to study the critical role of trust in electronic commerce extensively in the context of establishing initial trust between trading partners. Ongoing trust between partners can quickly be eroded through security or other trust violations. This paper examines whether customers are willing to transact with an eCommerce vendor in light of security and trust violations.

Design/methodology/approach

– The paper draws upon research in professional trust relationships and adapts it to the e-commerce context to create a process view of trust violation and repair. Using a design science framework, this paper employs agent-based modeling as the simulation technique to study the implications of security and trust violations on the willingness of customers to continue transacting with the vendor. The simulations are conducted for a variety of trust violations and reconciliation actions.

Findings

– While some of the results are predictable, the key finding for managers is that moderate reconciliation tactics are effective for all cases but the most severe trust violations, where trust is irrevocably broken. This has clear financial implications, particularly in cases where vendors may operate with small margins in competitive markets.

Originality/value

– Given the increasing push toward mobile and Internet-based commerce, and the large range of possible trust violations and security incidents in online purchases, coupled with increasing competition among vendors, it becomes imperative for vendors to provide effective tactics to repair customer trust violations when they arise.
Understanding users: from man-made typologies to computer-generated clusters
Authors: Gustav Johannsen Carl
Published: October 2014

Purpose

– The aim of this article is to identify the main approaches and discuss their perspectives, including their strengths and weaknesses in, especially, public library contexts. The purpose is also to present and discuss the results of a recent – 2014 – Danish library user segmentation project using computer-generated clusters. Compared to traditional marketing texts, this article also tries to identify users segments or images created by the library profession itself. Segmentation of users can help libraries in the process of understanding user similarities and differences. Segmentation can also form the basis for selecting segments as target users and for developing tailored services for specific target segments. Thus, several approaches and techniques have been tested in library contexts.

Design/methodology/approach

– Basically, the article is built upon a literature review concerning different approaches to user segmentation in, especially, public library context from approximately 1980 till now (May 2014).

Findings

– The article reveals that – at least – five different principal approaches to user segmentation have been applied by the library sector during the past 30-35 years. Characteristics, strengths and weaknesses of the different approaches are identified, discussed and evaluated.

Practical implications

– When making decisions on future library user surveys, it is certainly an advantage, concerning the ability to make qualified decision, to know what opportunities that are at hand for identifying important segments.

Originality/value

– Some of the approaches have been treated individually in the library literature; however, it is probably the first time that the professions own user images and metaphors are dealt with in a user segmentation context.
Improved edge detection mapping through stacking and integration: a case study in the Bathurst Mining Camp
Authors: Tschirhart Peter , Morris Bill
Published: October 2014

Airborne geophysical surveys provide spatially continuous regional data coverage, which directly reflects subsurface petrophysical differences and thus the underlying geology. A modern geologic mapping exercise requires the fusion of this information to complement what is typically limited regional outcrop. Often, interpretation of the geophysical data in a geological context is done qualitatively using total field and derivative maps. With a qualitative approach, the resulting map product may reflect the interpreter's bias. Source edge detection provides a quantitative means to map lateral physical property changes in potential and non‐potential field data. There are a number of Source edge detection algorithms, all of which apply a transformation to convert local signal inflections associated with source edges into local maxima. As a consequence of differences in their computation, the various algorithms generate slightly different results for any given source depth, geometry, contrast, and noise levels. To enhance the viability of any detected edge, it is recommended that one combines the output of several Source edge detection algorithms. Here we introduce a simple data compilation method, deemed edge stacking, which improves the interpretable product of Source edge detection through direct gridding, grid addition, and amplitude thresholding. In two examples, i.e., a synthetic example and a real‐world example from the Bathurst Mining Camp, New Brunswick, Canada, a number of transformation algorithms are applied to gridded geophysical data sets and the resulting Source edge detection solutions combined. Edge stacking combines the benefits and nuances of each Source edge detection algorithm; coincident or overlapping and laterally continuous solutions are considered more indicative of a true edge, whereas isolated points are taken as being indicative of random noise or false solutions. When additional data types are available, as in our example, they may also be integrated to create a more complete geologic model. The effectiveness of this method is limited only by the resolution of each survey data set and the necessity of lateral physical property contrasts. The end product aims at creating a petrophysical contact map, which, when integrated with known lithological outcrop information, can be led to an improved geological map.
Historically browsed jewelweed populations exhibit greater tolerance to deer herbivory than historically protected populations
Authors: Martin Laura J. , Agrawal Anurag A. , Kraft Clifford E.
Published: October 2014

Browsing by overabundant white‐tailed deer (Odocoileus virginianus) has altered ecological relationships in forest communities across eastern North America. Recent but limited work suggests that deer browsing also selects for particular plant defensive traits.

We hypothesized that browsing by deer has imposed selection on defensive traits in an annual native wildflower, orange jewelweed (Impatiens capensis).

To test this hypothesis, we collected individuals from 26 natural populations across a 5000 km2 area in New York State, USA. Half of these populations were historically protected from deer and half were exposed to heavy browsing. We planted individuals in common gardens subjected to natural deer browsing or no browsing.

Individuals from historically browsed populations exhibited significantly higher tolerance than those from historically protected populations. Herbivory by deer reduced lifetime fruit production by only 20% in historically browsed populations, as opposed to 57% in historically protected populations. Two mechanisms were correlated with this increased tolerance: increased number of flowering days and increased fruits per flowering node.

Synthesis. The increased tolerance of historically browsed populations suggests that these populations evolved increased tolerance or that historically protected populations lost tolerance over time. Variation in tolerance traits in native plant species may allow them to persist in the face of rapid ecological change.
Predictors of Abstinence from Heavy Drinking During Treatment in COMBINE and External Validation in PREDICT
Authors: Gueorguieva Ralitza , Wu Ran , O'Connor Patrick G. , Weisner Constance , Fucito Lisa M. , Hoffmann Sabine , Mann Karl , O'Malley Stephanie S.
Published: October 2014

Background

The goal of the current study was to use tree‐based methods (Zhang and Singer, 2010, Recursive Partitioning and Applications, 2nd ed. Springer, New York) to identify predictors of abstinence from heavy drinking in COMBINE (Anton et al. JAMA 2006; 295:2003), the largest study of pharmacotherapy for alcoholism in the United States to date, and to validate these results in PREDICT (Mann et al. Addict Biol 2012; 18:937), a parallel study conducted in Germany.

Methods

We compared a classification tree constructed according to purely statistical criteria to a tree constructed according to a combination of statistical criteria and clinical considerations for prediction of no heavy drinking during treatment in COMBINE. We considered over 100 baseline predictors. The tree approach was compared to logistic regression. The trees and a deterministic forest identified the most important predictors of no heavy drinking for direct testing in PREDICT.

Results

The tree built using both clinical and statistical considerations consisted of 4 splits based on consecutive days of abstinence (CDA) prior to randomization, age, family history of alcoholism, and confidence to resist drinking in response to withdrawal and urges. The tree based on statistical considerations with 4 splits also split on CDA and age but also on gamma‐glutamyl transferase level and drinking goal. Deterministic forest identified CDA, age, and drinking goal as the most important predictors. Backward elimination logistic regression among the top 18 predictors identified in the deterministic forest analyses identified only age and CDA as significant main effects. Longer CDA and goal of complete abstinence were associated with better outcomes in both data sets.

Conclusions

The most reliable predictors of abstinence from heavy drinking were CDA and drinking goal. Trees provide binary decision rules and straightforward graphical representations for identification of subgroups based on response and may be easier to implement in clinical settings.
Traditional Chinese medicinal herbal tea consumption, self‐reported somatization, and alexithymia
Authors: Chio Pit Hoi , Zaroff Charles M.
Published: October 2014

Introduction

Somatic presentations of distress are common cross‐culturally, although perhaps more so in Asian cultures. Somatic presentations of distress may be associated with alexithymia, a difficulty in experiencing and expressing emotions. Although the constructs of somatization and alexithymia have been examined in depth both within and across cultures, there is minimal information on culture‐specific behaviors utilized to cope with stress in individuals who tend to somaticize distress or are alexithymic. The current report investigates the association between somatization and alexithymia, and a culture‐specific behavior of traditional Chinese medicinal herbal tea consumption, in a nonclinical, young adult sample.

Methods

A sample of 222 undergraduate university students of Chinese ethnicity completed self‐report measures of somatization and the related construct of somatosensory amplification, alexithymia, and attitude toward the consumption of herbal tea possessing traditional Chinese medicinal value.

Results

After controlling for gender, alexithymia was significantly correlated with somatization (r[220] = 0.29, P < 0.05) and somatosensory amplification (r[220] = 0.19, P < 0.05). Attitudes toward herbal tea consumption were significantly correlated with somatosensory amplification (r[220] = 0.16, P < 0.05).

Discussion

The connection between alexithymia and somatization was confirmed in the current report in a nonclinical sample. A culture‐specific behavior (consumption of traditional Chinese medicinal herbal tea) was significantly associated with somatosensory amplification. Potential etiologies and implications of the current findings are discussed.
Simple faecal preparation and efficacy of frozen inoculum in faecal microbiota transplantation for recurrent Clostridium difficile infection – an observational cohort study
Authors: Satokari R. , Mattila E. , Kainulainen V. , Arkkila P. E. T.
Published: October 2014

Background

Faecal microbiota transplantation (FMT) is an effective treatment for recurrent Clostridium difficile infection (rCDI). The finding of suitable donor, donor screening and preparation of faecal transplants are challenging in clinical work.

Aim

To develop a practical protocol for preparing frozen transplants and to compare the efficacy of previously frozen and fresh faeces in treating rCDI.

Methods

Two healthy volunteers acted as universal donors for the frozen faecal preparations, which were prepared by suspending faeces into physiological saline, adding glycerol to a final concentration of 10% and storing at −80 °C. We compared the outcomes of patients with rCDI who had undergone FMT at colonoscopy and received infusion of previously prepared, freeze‐stored faeces (n = 23) or fresh faeces from individual (n = 15) or universal donors (n = 11) (total n = 49). Clinical failure was defined as persistent or recurrent symptoms with a positive C. difficile toxin stool test, and a need for new therapy.

Results

At 12 weeks post‐FMT, symptoms were resolved in 22 of 23 patients receiving previously frozen faeces, and in all 11 or 14 of 15 patients receiving fresh faeces from the universal or individual donors respectively (totally 25 of 26; P = ns, success rate 96%). Mild transient fever appeared for two patients receiving frozen faeces, but no other significant side effects were observed. 42 patients were followed up for a year post‐FMT and the success rate was 88% in both fresh and frozen faeces groups.

Conclusions

Preparation of frozen transplants simplifies the practical aspects of faecal microbiota transplantation without loss of efficacy or safety.
A Unification of Models for Meta-Analysis of Diagnostic Accuracy Studies without a Gold Standard
Authors: Liu Yulun , Chen Yong , Chu Haitao
Published: October 2014

Several statistical methods for meta-analysis of diagnostic accuracy studies have been discussed in the presence of a gold standard. However, in practice, the selected reference test may be imperfect due to measurement error, non-existence, invasive nature, or expensive cost of a gold standard. It has been suggested that treating an imperfect reference test as a gold standard can lead to substantial bias in the estimation of diagnostic test accuracy. Recently, two models have been proposed to account for imperfect reference test, namely, a multivariate generalized linear mixed model (MGLMM) and a hierarchical summary receiver operating characteristic (HSROC) model. Both models are very flexible in accounting for heterogeneity in accuracies of tests across studies as well as the dependence between tests. In this article, we show that these two models, although with different formulations, are closely related and are equivalent in the absence of study-level covariates. Furthermore, we provide the exact relations between the parameters of these two models and assumptions under which two models can be reduced to equivalent submodels. On the other hand, we show that some submodels of the MGLMM do not have corresponding equivalent submodels of the HSROC model, and vice versa. With three real examples, we illustrate the cases when fitting the MGLMM and HSROC models leads to equivalent submodels and hence identical inference, and the cases when the inferences from two models are slightly different. Our results generalize the important relations between the bivariate generalized linear mixed model and HSROC model when the reference test is a gold standard.
Changes in Elephant Abundance Affect Forest Composition or Regeneration?
Authors: Omeja Patrick A. , Jacob Aerin L. , Lawes Michael J. , Lwanga Jeremiah S. , Rothman Jessica M. , Tumwesigye Charles , Chapman Colin A.
Published: October 2014

While overall numbers of African elephant have declined dramatically in recent times, some populations are now confined to protected areas and are locally overabundant—an undesirable situation for both biodiversity conservation and elephants. In forested protected areas, options to manage elephants are limited because it is difficult to safely approach animals, yet it is vital that these populations are managed because browsing by elephants can dramatically alter forest ecosystems. Using data collected over 50 yr in Kibale National Park, Uganda, we examine the prediction that increasing elephant numbers and associated changes in their foraging behavior have caused a shift in tree community composition. Although the relative abundance of elephants increased significantly between 1996 and 2010, the population structure of their preferred tree food species did not change, nor did tree community composition change in favor of species able to re‐sprout after elephant damage. Furthermore, over the last 50 yr Kibale elephants have not become more selective foragers, as would be expected if more nutritious tree species were declining. However, elephants are more abundant in disturbed areas dominated by shrubs and grasses and appear to have arrested forest succession in these areas. At their current abundance, elephants have not selectively altered the composition of intact old growth forest, but they do inhibit the regeneration of disturbed areas.
Canopy Openness Enhances Diversity of Ant–Plant Interactions in the Brazilian Amazon Rain Forest
Authors: Dáttilo Wesley , Dyer Lee
Published: October 2014

In closed‐canopy tropical forest understory, light availability is a significant determinant of habitat diversity because canopy structure is highly variable in most tropical forests. Consequently, variation in canopy cover affects the composition and distribution of plant species via creating variable light environments. Nevertheless, little is known about how variation in canopy openness structures patterns of plant–animal interactions. Because of the great diversity and dominance of ants in tropical environments, we used ant–plant interactions as a focal network to evaluate how variation in canopy cover influences patterns of plant–insect interactions in the Brazilian Amazon rain forest. We observed that small increases in canopy openness are associated with increased diversity of ant–plant interactions in our study area, and this change is independent of plant or ant species richness. Additionally, we found smaller niche overlap for both ants and plants associated with greater canopy openness. We hypothesize that enhanced light availability increases the breadth of ant foraging sources because variation in light availability gives rise to plant resources of different quality and amounts. Moreover, greater light availability promotes vegetative growth in plants, creating ant foraging ‘bridges’ between plants. In sum, our results highlight the importance of environmental heterogeneity as a determinant of ant–plant interaction diversity in tropical environments.
Soil and Geographic Distance as Determinants of Floristic Composition in the Azuero Peninsula (Panama)
Authors: Garibaldi Cristina , Nieto‐Ariza Beatriz , Macía Manuel J. , Cayuela Luis
Published: October 2014

Many studies analyzing the relative contribution of soil properties versus distance‐related processes on plant species composition have focused on lowland tropical forests. Very few have investigated two forest types simultaneously, to contrast ecological processes that assemble the communities. This study analyses—at the landscape scale—the relative contribution of soil and distance on lowland and submontane tropical forests, which co‐occur in two reserves of the Azuero peninsula (Panama). Floristic inventories and soil sampling were conducted in 81 0.1‐ha plots clustered in 27 sites, and data were analyzed using Mantel tests, variance partitioning and non‐metric multidimensional scaling. The largest differences in floristic composition occurred between reserves in both forest types. Soil variation and geographic distance were important determinants of floristic composition, but their effects were highly correlated; together they explained 7–25 percent and 46–50 percent of the variation in lowland and submontane forests, respectively. Soil variables that had the best correlations with floristic composition were iron, zinc, and silt content in lowland, and calcium, copper, iron, potassium, magnesium, phosphorus, zinc, and sand content in submontane forests. The studied forests showed a high beta diversity that seems to be related primarily with soils and, secondarily, with dispersal limitation and stochastic events. The results reveal a response of tree assemblages to environmental gradients, which are particularly conspicuous in Panama. The effects of limited dispersal seem to be more important in submontane than in lowland forests, probably as a result of higher isolation.