bluuebunny/crossref_metadata_2025 huggingface dataset:
Specular and Diffuse Reflectance of Phase‐Separated Polymer Blend Films
Authors: Nallapaneni Asritha , Shawkey Matthew D. , Karim Alamgir
Published: April 2017

Diffuse reflectors have various applications in devices ranging from liquid crystal displays to light emitting diodes, to coatings. Herein, specular and diffuse reflectance from controlled phase separation of polymer blend films, a well‐known self‐organization process, are studied. Temperature‐induced spinodal phase separation of polymer blend films in which one of the components is selectively extracted is shown to exhibit enhanced surface roughness as compared to unextracted films, leading to a notable increase of diffuse reflectance. Diffuse reflectance of UV–visible light from such selectively leached phase‐separated blend films is determined by a synergy of varying lateral scale of phase separation (≈200 nm to 1 μm) and blend film surface roughness (0–40 nm). These critical parameters are controlled by tuning annealing time (0.5–3 h) and temperature (140, 150, 160 °C) of phase separation. Angle‐resolved diffuse reflection studies show that the surface‐roughened polymer films exhibit diffuse reflectance up to 40° from normal incident light in contrast to optically uniform as‐cast films that exhibit largely specular reflectance. Furthermore, the intensity of the diffusively reflected light can be enhanced (300–700 nm) or reduced (220–300 nm) significantly by coating the leached phase‐separated films with a thin silver over layer.

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Induced plant defences in biological control of arthropod pests: a double‐edged sword
Authors: Pappas Maria L , Broekgaarden Colette , Broufas George D , Kant Merijn R , Messelink Gerben J , Steppuhn Anke , Wäckers Felix , van Dam Nicole M
Published: April 2017

Biological control is an important ecosystem service delivered by natural enemies. Together with breeding for plant defence, it constitutes one of the most promising alternatives to pesticides for controlling herbivores in sustainable crop production. Especially induced plant defences may be promising targets in plant breeding for resistance against arthropod pests. Because they are activated upon herbivore damage, costs are only incurred when defence is needed. Moreover, they can be more specific than constitutive defences. Nevertheless, inducible defence traits that are harming plant pest organisms may interfere with biological control agents, such as predators and parasitoids. Despite the vast fundamental knowledge on plant defence mechanisms and their effects on natural enemies, our understanding of the feasibility of combining biological control with induced plant defence in practice is relatively poor. In this review, we focus on arthropod pest control and present the most important features of biological control with natural enemies and of induced plant defence. Furthermore, we show potential synergies and conflicts among them and, finally, identify gaps and list opportunities for their combined use in crop protection. We suggest that breeders should focus on inducible resistance traits that are compatible with the natural enemies of arthropod pests, specifically traits that help communities of natural enemies to build up. © 2017 The Authors.Pest Management Sciencepublished by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Thermoelectric converters with optimum graded materials and current distribution in one dimension and three dimensions
Authors: Gerstenmaier York Christian , Wachutka Gerhard
Published: April 2017

The description of TE‐converter performance with inhomogeneous material distribution is based on the classical Onsager–deGroot–Callen transport theory. A variational approach for performance maximization is generalized from previous 1D heat‐ and electric current distribution to general 3D devices by use of partial differential equations. The concept of multi‐stage (cascaded) TE‐converters in 1D is generalized to arbitrarily distributed electric current sources in the 3D case by introducing an extended version of the Onsager–deGroot–Callen theory. Originally insufficient material properties together with optimized current distribution allow for maximum performance with respect to a general distribution function of the thermoelectric figure of merit Z(x, T) depending simultaneously on 3D position x and local temperature T. Thermally isolating as well as non‐isolating boundary‐conditions are treated. Investigation of hitherto unsolved problems of the 1D theory leads to a new analytical solution of maximized generated electric power for optimized grading. In previous literature analytical formulas had been established for 1D TE‐efficiencies. For the outstanding maximization problem of cooling power improved results are obtained by fast inversion of tridiagonal matrices compared to previous findings with differential equation initial value algorithms. An analytic calculation is possible by optimizing the temperature extremum location in a piecewise linear profile. By its construction a close lower bound to the exact cooling power is formed, which is possibly identical to the exact value.
The influence of N content on structure, phase stability, elastic and electronic properties in Ti3AlC2−xNx (x = 0–2)
Authors: Qin Xia , Zhang Peigen , Wang Shun , Du Yulei , Zhang Yamei , Sun Zhengming
Published: April 2017

Ab inito calculations have been carried out to investigate the structure, phase stability, elastic and electronic properties of the solid solution of Ti3AlC2−xNx (x = 0–2), which were compared with the isostructural and already synthesized end member Ti3AlC2. The substitution of C atoms by N atoms affects the structural parameters a and c. The differences of atomic radius and the bond lengths lead to the changes of structural parameters. Results indicate that Ti3AlCN has the lowest formation energy among the solid solutions, and from the calculation of the cohesive energy, it is found that the stabilities of Ti3AlC2−xNx (x = 0–2) decrease as more N atoms substitute C atoms. The elastic moduli increase as more C atoms are replaced with N atoms. As x increases, Ti3AlC2−xNx solid solutions become stiffer than Ti3AlC2. The calculated density of states suggests that the conductivity of Ti3AlC2−xNx originates from the Ti‐3d contribution and the electrical conductivity becomes higher as more N atoms substitute C atoms.
A GLR control chart for monitoring a multinomial process
Authors: Lee Jaeheon , Peng Yiming , Wang Ning , Reynolds Marion R.
Published: April 2017

The problem of detecting changes in the parameter p in a Bernoulli process with two possible categories for each observation has been extensively investigated in the SPC literature, but there is much less work on detecting changes in the vector parameter p in a multinomial process where there are more than two categories. A few papers have considered the case in which the direction of the change in p is known, but there is almost no work for the important case in which the direction of the change is unknown and individual observations are obtained. This paper proposes a multinomial generalized likelihood ratio (MGLR) control chart based on a likelihood ratio statistic for monitoring p when individual observations are obtained and the direction and size of the change in p are unknown. A set of 2‐sided Bernoulli cumulative sum (CUSUM) charts is proposed as a reasonable competitor of the MGLR chart. It is shown that the MGLR chart has better overall performance than the set of 2‐sided Bernoulli CUSUM charts over a wide range of unknown shifts. Equations are presented for obtaining the control limit of the MGLR chart when there are three or four components in p.
A novel mass spectrometric method for formaldehyde in children's personal‐care products and water via derivatization with acetylacetone
Authors: Backe Will J.
Published: April 2017

Rationale

New legislation in the state of Minnesota prohibits the sale of children's personal‐care products (PCPs) that contain more than 500 ng/mg formaldehyde. Previous attempts to quantify formaldehyde in PCPs use nonspecific derivatization procedures that employ harsh reagents and/or nonspecific detection. Derivatization of formaldehyde by acetylacetone occurs under mild conditions and is specific for formaldehyde but it has not been investigated using high‐performance liquid chromatography/tandem mass‐spectrometry (HPLC/MS/MS).

Methods

To determine formaldehyde, PCPs were dissolved and then interferences were minimized by graphitized‐carbon solid‐phase extraction. Formaldehyde was derivatized to 3,5‐diacetyl‐1,4‐dihydrolutidine (DDL) using an acetylacetone solution. Post‐derivatization, samples were diluted and analyzed by HPLC/MS/MS. Quantification was performed by isotopic dilution. Product‐ion spectra were acquired for DDL and D12‐DDL. The mass shifts between the two product‐ion spectra were used to assign fragment structures. To confirm molecular formulas, high‐resolution accurate‐mass analysis of the DDL product ions was performed by quadrupole time‐of‐flight MS.

Results

Structures were proposed for all product ions of DDL above 10% relative intensity. Method accuracy ranged between 96–104% for all matrices at all concentrations tested. Method precision was less than 4% relative standard deviation. The reporting limit was 10 ng/mg in PCPs and 100 μg/L in water. Twenty children's PCPs were tested to demonstrate the method and formaldehyde was reported in five from 23–1500 ng/mg. Of those five, two samples contained formaldehyde above the Minnesota regulatory limit.

Conclusions

The developed method allows for the accurate quantification of formaldehyde in PCPs at levels below those required by a new regulation on children's products in Minnesota. The method includes a derivatization procedure that is newly adapted to HPLC/MS/MS; therefore, structures were proposed for the product ions of the derivative (DDL). Copyright © 2017 John Wiley & Sons, Ltd.
An adaptive and fully automatic method for estimating the 3D position of bendable instruments using endoscopic images
Authors: Cabras Paolo , Nageotte Florent , Zanne Philippe , Doignon Christophe
Published: April 2017

Background

Flexible bendable instruments are key tools for performing surgical endoscopy. Being able to measure the 3D position of such instruments can be useful for various tasks, such as controlling automatically robotized instruments and analyzing motions.

Methods

An automatic method is proposed to infer the 3D pose of a single bending section instrument, using only the images provided by a monocular camera embedded at the tip of the endoscope. The proposed method relies on colored markers attached onto the bending section. The image of the instrument is segmented using a graph‐based method and the corners of the markers are extracted by detecting the color transitions along Bézier curves fitted on edge points. These features are accurately located and then used to estimate the 3D pose of the instrument using an adaptive model that takes into account the mechanical play between the instrument and its housing channel.

Results

The feature extraction method provides good localization of marker corners with images of the in vivo environment despite sensor saturation due to strong lighting. The RMS error on estimation of the tip position of the instrument for laboratory experiments was 2.1, 1.96, and 3.18 mm in the x, y and z directions, respectively. Qualitative analysis in the case of in vivo images shows the ability to correctly estimate the 3D position of the instrument tip during real motions.

Conclusions

The proposed method provides an automatic and accurate estimation of the 3D position of the tip of a bendable instrument in realistic conditions, where standard approaches fail.
Decentralized minimal‐time planar formation control of multi‐agent system
Authors: Ou Linlin , Zou Chao , Yu Xinyi
Published: April 2017

In this paper, the problems of decentralized minimal‐time planar formation control are investigated for both static and dynamic cases. For the static one, the discrete‐time dynamics of multi‐agent system in which each agent exchanges information according to a complex weighted network is studied. On the basis of a minimal polynomial, a decentralized minimal‐time static formation method is proposed to compute the final formation positions of the agents in the minimal number of steps without global coordinates. The proposed method allows an arbitrarily chosen agent in the network to compute its final formation position. For the dynamic one in a leader–follower framework, the path information of the agents satisfies linear regression equations that are determined by interaction topology and input signals. In order to obtain the coefficients of such linear regression equations, a Kronecker‐theorem‐based algorithm is presented. Similar to the results for the static case, any agent is allowed to use the minimum number of successive history state values to compute the future dynamic formation track. The minimal number of steps can be computed by checking the rank condition of the Hankel matrix constructed in terms of the path information. Meanwhile, the simulation examples are given to demonstrate the validity of the proposed minimal‐time planar formation control methods. The results in the paper combine the matrix polynomial analysis into the framework of formation control design and show how to predict the motion of the agents in a decentralized manner. Copyright © 2017 John Wiley & Sons, Ltd.
Data‐driven fault diagnosis and robust control: Application to PEM fuel cell systems
Authors: Ocampo‐Martinez Carlos , Sánchez‐Peña Ricardo , Bianchi Fernando , Ingimundarson Ari
Published: April 2017

A data‐driven methodology that includes the unfalsified control concept in the framework of fault diagnosis and isolation (FDI) and fault‐tolerant control (FTC) is presented. The selection of the appropriate controller from a bank of controllers in a switching supervisory control setting is performed by using an adequate FDI outcome. By combining simultaneous online performance assessment of multiple controllers with the fault diagnosis decision from structured hypothesis tests, a diagnosis statement regarding what controller is most suitable to deal with the current (nominal or faulty) mode of the plant is obtained. Switching strategies that use the diagnosis statement are also proposed. This approach is applied to a nonlinear experimentally validated model of the breathing system of a polymer electrolyte membrane fuel cell. The results show the effectiveness of this FDI–fault‐tolerant control data‐driven methodology. Copyright © 2017 John Wiley & Sons, Ltd.
Controllability and observability of ann‐link robot with multiple active links
Authors: Hao Yuqing , Duan Zhisheng , Wen Guanghui
Published: April 2017

This paper considers ann‐link planar robot moving in the vertical plane with multiple active links. The controllability and observability of the robot around the upright equilibrium point, which are important for the existence of an output‐feedback controller, are investigated in detail. Specific properties of the mechanical parameters are extracted to demonstrate that when there are adjacent active links, the robot is strongly structurally controllable and observable around the upright equilibrium point. When the active links are not adjacent to each other, a necessary and sufficient condition is established to ensure the linear controllability and observability. Finally, the theoretical results are illustrated via several practical examples. Copyright © 2017 John Wiley & Sons, Ltd.
Embracing the future
Authors: Heeg Robert
Published: April 2017

The search for talent
Where storytelling ends and communication begins
Authors: Davison Lucy
Published: April 2017

THE ESSENTIAL SKILLS FOR THE RESEARCHER OF THE FUTURE
Lost in translation?
Authors: Forsyth John
Published: April 2017

Why is it that some of researchers’ best ideas never get used by the client, and yet clients often feel they lack the insights they need, no matter how much research and analytics they commission? John Forsyth talks to three in‐house heads of insight about where the problem–and the solution–might lie.
Business in Today's Latin American Society
Authors: Landers Stephanie
Published: April 2017

Responding to social challenges and changes
Foxes, hedgehogs, and the future of market research
Authors: Baker Reg , Smith David
Published: April 2017

Our industry is now well into its second decade of innovation, debate, and soul searching about what the future of market research will look like. All we can say with certainty is that our world has changed and will continue to change with no end in sight. Three features of this new reality are driving fundamental changes in how we do research and the skills and expertise needed to do it well.
We need more replication research – A case for test-retest reliability
Authors: Leppink Jimmie , Pérez-Fuster Patricia
Published: April 2017

Following debates in psychology on the importance of replication research, we have also started to see pleas for a more prominent role for replication research in medical education. To enable replication research, it is of paramount importance to carefully study the reliability of the instruments we use. Cronbach’s alpha has been the most widely used estimator of reliability in the field of medical education, notably as some kind of quality label of test or questionnaire scores based on multiple items or of the reliability of assessment across exam stations. However, as this narrative review outlines, Cronbach’s alpha or alternative reliability statistics may complement but not replace psychometric methods such as factor analysis. Moreover, multiple-item measurements should be preferred above single-item measurements, and when using single-item measurements, coefficients as Cronbach’s alpha should not be interpreted as indicators of the reliability of a single item when that item is administered after fundamentally different activities, such as learning tasks that differ in content. Finally, if we want to follow up on recent pleas for more replication research, we have to start studying the test-retest reliability of the instruments we use.
Extending the theoretical framework for curriculum integration in pre-clinical medical education
Authors: Vergel John , Stentoft Diana , Montoya Juny
Published: April 2017

Introduction Curriculum integration is widely discussed in medical education but remains ill defined. Although there is plenty of information on logistical aspects of curriculum integration, little attention has been paid to the contextual issues that emerge from its practice and may complicate students’ knowledge integration. Therefore, we aimed to uncover how curriculum integration is manifested through context.

Methods We collected data from the official curriculum and interviewed ten participants (including curriculum designers, facilitators, and students) in the bachelor’s medical program at Aalborg University. We observed various learning activities focused on pre-clinical education. Inspired by grounded theory, we analyzed the information we gathered.

Results The following theoretical constructs emerged after the inductive analysis: 1) curriculum integration complexity is embedded in the institutional learning perspectives; 2) curriculum integration is used to harmonize conflicting learning perspectives in curriculum practice; 3) curriculum integration creates tensions that self-organize its structure; and 4) curriculum integration becomes visible in collaborative learning spaces.

Discussion These constructs provide a framework for analyzing curriculum integration in the context in which it is meant to appear, which may assist educationalists to gain a more specific understanding of the term. This may enable effective curriculum integration since contextual issues are addressed in addition to the goals specified in the official curriculum.
A qualitative study of undergraduate clerkships in the intensive care unit: It’s a brand new world
Authors: O’Connor Enda , Moore Michael , Cullen Walter , Cantillon Peter
Published: April 2017

Introduction While ICU clerkships are commonplace in undergraduate medical education, little is known about how students learn there. This study aimed to explore students’ perceptions of the ICU as a learning environment, the factors influencing their learning and any perceived differences between learning in the ICU and non-ICU settings.

Methods We used interpretivist methodology, a social cognitive theoretical framework and a qualitative descriptive strategy. Ten medical students and four graduate doctors participated in four semi-structured focus group discussions. Data were analyzed by six-step thematic data analysis. Peer debriefing, audit trail and a reflexive diary were used.

Results Social cognitive influences on learning were apparent in the discussions. Numerous differences emerged between ICU and non-ICU clinical clerkships, in particular an unfamiliarity with the environment and the complex illness, and difficulty preparing for the clerkship. A key emergent theme was the concept of three phases of student learning, termed pre-clerkship, early clerkship and learning throughout the clerkship. A social cognitive perspective identified changes in learner agency, self-regulatory activities and reciprocal determinism through these phases. The findings were used to construct a workplace model of undergraduate intensive care learning, providing a chronological perspective on the clerkship experience.

Conclusions The ICU, a rich, social learning environment, is different in many respects to other hospital settings. Students navigate through three phases of an ICU clerkship, each with its own attendant emotional, educational and social challenges and with different dynamics between learner and environment.
Disinfection of the Radiologist Workstation and Radiologist Hand Hygiene: A Single Institution Practice Quality Improvement Project
Authors: Quon Jeffrey S. , Dilauro Marc , Ryan John G.
Published: April 2017

Purpose

The purpose of this study was to evaluate the workstation disinfection rates and hand hygiene of radiologists and trainees at shared departmental workstations and assess the impact of education and reminder placards on daily habits.

Methods

A 10-question survey was administered to all staff radiologists, fellows, and residents at our institution. The questions pertained to workstation disinfection, hand hygiene habits, and accessibility to disinfectant wipes and hand sanitizer stations. Subsequently, a short educational PowerPoint presentation was emailed to the department and small reminder placards were placed at each workstation. A follow-up survey was administered. Chi-square and Wilcoxon signed-rank tests were used to analyse the results.

Results

The percentage of participants who disinfect their workstations 1-2 times/week, 3-4 times/week or everyday increased from 53.4% (45 of 84 participants) to 74.3% (55 of 74 participants; P = .01), while the number who disinfect their workstation <1 time/week or never decreased from 46.4% (39 of 84 participants) to 25.7% (19 of 74 participants; P = .01). Hand washing before working at the workstation increased from 41.6% (35 of 84 participants) to 48.7% (36 of 74 participants; P = .76) and hand washing after working at the workstation increased from 50.0% (42 of 84 participants) to 56.8% (42 of 74 participants; P = .49).

Conclusions

At our institution, the implementation of daily reminder placards at each workstation and the administration of an educational PowerPoint presentation improved the rate of radiologist workstation disinfection.
Protein Array-Based Approaches for Biomarker Discovery in Cancer
Authors: Huang Yi , Zhu Heng
Published: April 2017

Biomarkers are deemed to be potential tools in early diagnosis, therapeutic monitoring, and prognosis evaluation for cancer, with simplicity as well as economic advantages compared with computed tomography and biopsy. However, most of the current cancer biomarkers present insufficient sensitivity as well as specificity. Therefore, there is urgent requirement for the discovery of biomarkers for cancer. As one of the most exciting emerging technologies, protein array provides a versatile and robust platform in cancer proteomics research because it shows tremendous advantages of miniaturized features, high throughput, and sensitive detections in last decades. Here, we will present a relatively complete picture on the characteristics and advance of different types of protein arrays in application for biomarker discovery in cancer, and give the future perspectives in this area of research.
Hydroxyurea for nontransfusion-dependent β-thalassemia
Authors: Algiraigri Ali H. , Wright Nicola A.M. , Paolucci Elizabeth Oddone , Kassam Aliya
Published: April 2017

Objective/background:

Nontransfusion-dependent β-thalassemia (NTDβT) syndromes consist of β-thalassemia intermedia and moderate hemoglobin E/β thalassemias. They are characterized by varying degrees of chronic anemia and a wide spectrum of complications due to ineffective erythropoiesis and iron overload from chronic transfusions. Hydroxyurea (HU), an oral chemotherapeutic drug, is anticipated to decrease disease severity.

Methods:

We performed a meta-analysis to evaluate the clinical efficacy and safety of HU in NTDβT patients of any age. MEDLINE, EMBASE, Cochrane databases, and major conference proceedings for studies that assessed HU in NTDβT patients were searched. Qualities of eligible studies were assessed by National Institutes of Health tools.

Results:

Seventeen studies, collectively involving 709 patients, fulfilled the eligibility criteria. HU was associated with a significant decrease in transfusion need in severe NTDβT with complete and overall (≥50%) response rates of 42% and 79%, respectively. For mild NTDβT, HU was effective in raising hemoglobin by 1 g/L in 64% of patients.

Conclusion:

HU appears to be effective, well tolerated, and associated with mild and transient adverse events. NTDβT patients may benefit from a trial of HU, although large randomized clinical trials assessing its efficacy should be conducted to confirm the findings of this metaanalysis and to assess its long-term toxicity and response sustainability.
Volatility measures as predictors of extreme returns
Authors: Switzer Lorne N. , Tahaoglu Cagdas , Zhao Yun
Published: April 2017

This paper examines the relationship between volatility and the probability of occurrence of expected extreme returns in the Canadian market. Four measures of volatility are examined: implied volatility from firm option prices, conditional volatility calculated using an EGARCH model, idiosyncratic volatility, and expected shortfall. A significantly positive relationship is observed between a firm's idiosyncratic volatility and the probability of occurrence of an extreme return in the subsequent month for firms. A 10% increase in idiosyncratic volatility in a given month is associated with the probability of an extreme shock in the subsequent month (top or bottom 1.5% of the returns distribution) of 26.4%. Other firm characteristics, including firm age, price, volume and book‐to‐market ratio, are also shown to be significantly related to subsequent firm extreme returns. The effects of conditional and implied volatility are mixed. The E‐GARCH and expected shortfall measures of conditional volatility are consistent with mean reversion: high short term realizations of conditional volatility foreshadow a lower probability of extreme returns.
Nonequilibrium Gas Dynamics and Molecular Simulation
Authors: Boyd Iain D. , Schwartzentruber Thomas E.
Published: April 2017

This current and comprehensive book provides an updated treatment of molecular gas dynamics topics for aerospace engineers, or anyone researching high-temperature gas flows for hypersonic vehicles and propulsion systems. It demonstrates how the areas of quantum mechanics, kinetic theory, and statistical mechanics can combine in order to facilitate the study of nonequilibrium processes of internal energy relaxation and chemistry. All of these theoretical ideas are used to explain the direct simulation Monte Carlo (DSMC) method, a numerical technique based on molecular simulation. Because this text provides comprehensive coverage of the physical models available for use in the DSMC method, in addition to the equations and algorithms required to implement the DSMC numerical method, readers will learn to solve nonequilibrium flow problems and perform computer simulations, and obtain a more complete understanding of various physical modeling options for DSMC than is available in other texts.
Fluid sample injectors for x-ray free electron laser at SACLA
Authors: Tono Kensuke
Published: April 2017

This paper provides a review on sample injectors which are provided at SPring-8 Angstrom Compact free electron LAser (SACLA) for conducting serial measurement in a ‘diffract-before-destroy’ scheme using an x-ray free electron laser (XFEL). Versatile experimental platforms at SACLA are able to accept various types of injectors, among which liquid-jet, droplet and viscous carrier injectors are frequently utilized. These injectors produce different forms of fluid targets such as a liquid filament with a diameter in the order of micrometer, micro-droplet synchronized to XFEL pulses, and slowly flowing column of highly viscous fluid with a rate below $1~\unicode[STIX]{x03BC}\text{L}~\text{min}^{-1}$. Characteristics and applications of the injectors are described.
DEMETRIUS OF LACONIA AND THE DEBATE BETWEEN THE STOICS AND THE EPICUREANS ON THE NATURE OF PARENTAL LOVE
Authors: McConnell Sean
Published: April 2017

Epicurus denies that human beings have natural parental love for their children, and his account of the development of justice and human political community does not involve any natural affinity between human beings in general but rather a form of social contract. The Stoics to the contrary assert that parental love is natural; and, moreover, they maintain that natural parental love is the first principle of social οἰκείωσις, which provides the basis for the naturalness of justice and human political community. The Stoics are, therefore, obliged to refute Epicurus’ denial of the naturalness of parental love in order to support their own theory of social οἰκείωσις; and we have good evidence for the arguments that they employed against the Epicureans on this account. Likewise, the Epicureans are obliged not only to defend their own position but also to undermine the competing Stoic theory of social οἰκείωσις; and the foundational premise of a natural bond between parent and child is an obvious target. However, beyond dogmatically restating Epicurus’ denial of natural parental love, the evidence for the Epicurean line of attack against the Stoics is currently unclear. In this paper I argue that we can go some way towards uncovering it via an analysis of some fragmentary passages from an unidentified work of the Epicurean Demetrius of Laconia (c.150–75b.c.) that contain a puzzling discussion of Epicurus’ stance on parental love.
Posttraumatic stress disorder in the World Mental Health Surveys
Authors: Koenen K. C. , Ratanatharathorn A. , Ng L. , McLaughlin K. A. , Bromet E. J. , Stein D. J. , Karam E. G. , Meron Ruscio A. , Benjet C. , Scott K. , Atwoli L. , Petukhova M. , Lim C. C.W. , Aguilar-Gaxiola S. , Al-Hamzawi A. , Alonso J. , Bunting B. , Ciutan M. , de Girolamo G. , Degenhardt L. , Gureje O. , Haro J. M. , Huang Y. , Kawakami N. , Lee S. , Navarro-Mateu F. , Pennell B.-E. , Piazza M. , Sampson N. , ten Have M. , Torres Y. , Viana M. C. , Williams D. , Xavier M. , Kessler R. C.
Published: April 2017

Background

Traumatic events are common globally; however, comprehensive population-based cross-national data on the epidemiology of posttraumatic stress disorder (PTSD), the paradigmatic trauma-related mental disorder, are lacking.

Methods

Data were analyzed from 26 population surveys in the World Health Organization World Mental Health Surveys. A total of 71 083 respondents ages 18+ participated. The Composite International Diagnostic Interview assessed exposure to traumatic events as well as 30-day, 12-month, and lifetime PTSD. Respondents were also assessed for treatment in the 12 months preceding the survey. Age of onset distributions were examined by country income level. Associations of PTSD were examined with country income, world region, and respondent demographics.

Results

The cross-national lifetime prevalence of PTSD was 3.9% in the total sample and 5.6% among the trauma exposed. Half of respondents with PTSD reported persistent symptoms. Treatment seeking in high-income countries (53.5%) was roughly double that in low-lower middle income (22.8%) and upper-middle income (28.7%) countries. Social disadvantage, including younger age, female sex, being unmarried, being less educated, having lower household income, and being unemployed, was associated with increased risk of lifetime PTSD among the trauma exposed.

Conclusions

PTSD is prevalent cross-nationally, with half of all global cases being persistent. Only half of those with severe PTSD report receiving any treatment and only a minority receive specialty mental health care. Striking disparities in PTSD treatment exist by country income level. Increasing access to effective treatment, especially in low- and middle-income countries, remains critical for reducing the population burden of PTSD.
The Myth of the Peasant in the Global Organic Farming Movement
Authors: Barton Gregory A.
Published: April 2017

Organic farming activists have promoted the idea that ancient peasant wisdom informed the basic principles or Albert Howard’s Indore method, and of organic farming generally. The myth of the peasant origins of organic farming has influenced environmental activists and historians alike and concealed the remarkable contributions of Albert Howard and his first and second wives, Gabrielle and Louise Howard. A few statements made by Howard himself, and by his second wife, Louise, inspired the myth of peasant origins of organic wisdom. But a closer look at the published and unpublished writings of the Howards show that the formulation of the Indore method, which lies at the heart of organic farming, is a strict scientific protocol with its roots in the scientific work of Albert Howard and his cohorts.
Seed germination in cleistogamous species: theoretical considerations and a literature survey of experimental results
Authors: Baskin Jerry M. , Baskin Carol C.
Published: April 2017

A cleistogamous species consists of individuals that produce both chasmogamous (open, CH) and cleistogamous (permanently closed, CL) flowers, which facilitates a mixed-mating system. In contrast to what one might expect, CL (obligately selfed) seeds and the plants derived from them can be more fit than CH (potentially outcrossed) seeds and the plants they give rise to. Our aim was to review some theoretical aspects of mixed mating in relation to retention of both CH and CL in cleistogamous species and to determine if data on germination support the notion that CL is advantageous over that of CH. Based on germination (or seedling emergence) of CHvsCL seeds in 29 species in 21 genera and 11 families of monocots and eudicots, CL seeds germinated better in 107 and equally well as in 64 of 252 case studies as CH seeds (67.9%), and the (CH < CL):(CH > CL) ratio was 107/81 (1.32). We conclude that our study lends support to the notion that production of CL seeds by cleistogamous species is advantageous over that of CH seeds. Retention of CH by CL species may be due to the need to prevent complete selfing (s= 1.0) and thus total inbreeding depression (δ), which theory predicts would decrease reproductive success. Some caveats concerning the results of comparative studies on the germination biology of CHvsCL seeds of amphicarpicsensu strictoFabaceae species andCommelina benghalensisand the aerial cleistogamous grassDanthonia spicataare discussed.
The Birth of Representative Institutions: The Case of the Crown of Aragon
Authors: Møller Jørgen
Published: April 2017

A new research agenda within political science and economics has been devoted to elucidating the development of medieval representative institutions. However, if we wish to get a clearer grasp of the birth of representative institutions, much more detailed data are needed. This paper introduces and interrogates a new data set on assemblies in one of the first instances where representative institutions arose: the Crown of Aragon. An analysis of these new data, which cover the period 1100–1327, supports several important conclusions. First, the development of representative institutions took place in a couple of brief “bursts” of activity. Second, factors pertaining to the establishment of public order (land peace and the regulation of succession) feature as more important than “geopolitical” factors (war and taxation) in the early part of the period, but the latter factors become more important after assemblies turn representative; indeed, they turn out to be crucial for understanding how assemblies eventually came to constrain rulers. A comparison with the only other early case of representative institutions on which there are good data, thirteenth- and early-fourteenth-century England, supports a third finding: There is a striking, temporal parallelism in the development of representative institutions across the two realms.
Imatinib mesylate inhibits STAT5 phosphorylation in response to IL-7 and promotes T cell lymphopenia in chronic myelogenous leukemia patients
Authors: Thiant S , Moutuou M M , Laflamme P , Sidi Boumedine R , Leboeuf D M , Busque L , Roy J , Guimond M
Published: April 2017

Imatinib mesylate (IM) therapy has been shown to induce lower T cell counts in chronic myelogenous leukemia (CML) patients and an interference of IM with T cell receptor (TCR) signaling has been invoked to explain this observation. However, IL-7 and TCR signaling are both essential for lymphocyte survival. This study was undertaken to determine whether IM interferes with IL-7 or TCR signaling to explain lower T cell counts in patients. At diagnosis, CML patients have typically lower CD4+ counts in their blood, yet CD8+ counts are normal or even increased in some. Following the initiation of IM treatment, CD4+ counts were further diminished and CD8+ T lymphocytes were dramatically decreased. In vitro studies confirmed IM interference with TCR signaling through the inhibition of ERK phosphorylation and we showed a similar effect on IL-7 signaling and STAT5 phosphorylation (STAT5-p). Importantly however, using an in vivo mouse model, we demonstrated that IM impaired T cell survival through the inhibition of IL-7 and STAT5-p but not TCR signaling which remained unaffected during IM therapy. Thus, off-target inhibitory effects of IM on IL-7 and STAT5-p explain how T cell lymphopenia occurs in patients treated with IM.
Spiral volumetric optoacoustic tomography visualizes multi-scale dynamics in mice
Authors: Deán-Ben X Luís , Fehm Thomas F , Ford Steven J , Gottschalk Sven , Razansky Daniel
Published: April 2017

Imaging dynamics at different temporal and spatial scales is essential for understanding the biological complexity of living organisms, disease state and progression. Optoacoustic imaging has been shown to offer exclusive applicability across multiple scales with excellent optical contrast and high resolution in deep-tissue observations. Yet, efficient visualization of multi-scale dynamics remained difficult with state-of-the-art systems due to inefficient trade-offs between image acquisition time and effective field of view. Herein, we introduce the spiral volumetric optoacoustic tomography technique that provides spectrally enriched high-resolution contrast across multiple spatiotemporal scales. In vivo experiments in mice demonstrate a wide range of dynamic imaging capabilities, from three-dimensional high-frame-rate visualization of moving organs and contrast agent kinetics in selected areas to whole-body longitudinal studies with unprecedented image quality. The newly introduced paradigm shift in imaging of multi-scale dynamics adds to the multifarious advantages provided by the optoacoustic technology for structural, functional and molecular imaging.
Chemical labelling for visualizing native AMPA receptors in live neurons
Authors: Wakayama Sho , Kiyonaka Shigeki , Arai Itaru , Kakegawa Wataru , Matsuda Shinji , Ibata Keiji , Nemoto Yuri L. , Kusumi Akihiro , Yuzaki Michisuke , Hamachi Itaru
Published: April 2017

The location and number of neurotransmitter receptors are dynamically regulated at postsynaptic sites. However, currently available methods for visualizing receptor trafficking require the introduction of genetically engineered receptors into neurons, which can disrupt the normal functioning and processing of the original receptor. Here we report a powerful method for visualizing native α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors (AMPARs) which are essential for cognitive functions without any genetic manipulation. This is based on a covalent chemical labelling strategy driven by selective ligand-protein recognition to tether small fluorophores to AMPARs using chemical AMPAR modification (CAM) reagents. The high penetrability of CAM reagents enables visualization of native AMPARs deep in brain tissues without affecting receptor function. Moreover, CAM reagents are used to characterize the diffusion dynamics of endogenous AMPARs in both cultured neurons and hippocampal slices. This method will help clarify the involvement of AMPAR trafficking in various neuropsychiatric and neurodevelopmental disorders.
Targeted activation of diverse CRISPR-Cas systems for mammalian genome editing via proximal CRISPR targeting
Authors: Chen Fuqiang , Ding Xiao , Feng Yongmei , Seebeck Timothy , Jiang Yanfang , Davis Gregory D.
Published: April 2017

Bacterial CRISPR–Cas systems comprise diverse effector endonucleases with different targeting ranges, specificities and enzymatic properties, but many of them are inactive in mammalian cells and are thus precluded from genome-editing applications. Here we show that the type II-B FnCas9 from Francisella novicida possesses novel properties, but its nuclease function is frequently inhibited at many genomic loci in living human cells. Moreover, we develop a proximal CRISPR (termed proxy-CRISPR) targeting method that restores FnCas9 nuclease activity in a target-specific manner. We further demonstrate that this proxy-CRISPR strategy is applicable to diverse CRISPR–Cas systems, including type II-C Cas9 and type V Cpf1 systems, and can facilitate precise gene editing even between identical genomic sites within the same genome. Our findings provide a novel strategy to enable use of diverse otherwise inactive CRISPR–Cas systems for genome-editing applications and a potential path to modulate the impact of chromatin microenvironments on genome modification.
Multi-scale chromatin state annotation using a hierarchical hidden Markov model
Authors: Marco Eugenio , Meuleman Wouter , Huang Jialiang , Glass Kimberly , Pinello Luca , Wang Jianrong , Kellis Manolis , Yuan Guo-Cheng
Published: April 2017

Chromatin-state analysis is widely applied in the studies of development and diseases. However, existing methods operate at a single length scale, and therefore cannot distinguish large domains from isolated elements of the same type. To overcome this limitation, we present a hierarchical hidden Markov model, diHMM, to systematically annotate chromatin states at multiple length scales. We apply diHMM to analyse a public ChIP-seq data set. diHMM not only accurately captures nucleosome-level information, but identifies domain-level states that vary in nucleosome-level state composition, spatial distribution and functionality. The domain-level states recapitulate known patterns such as super-enhancers, bivalent promoters and Polycomb repressed regions, and identify additional patterns whose biological functions are not yet characterized. By integrating chromatin-state information with gene expression and Hi-C data, we identify context-dependent functions of nucleosome-level states. Thus, diHMM provides a powerful tool for investigating the role of higher-order chromatin structure in gene regulation.
Multi-component quantitative magnetic resonance imaging by phasor representation
Authors: Vergeldt Frank J. , Prusova Alena , Fereidouni Farzad , Amerongen Herbert van , Van As Henk , Scheenen Tom W. J. , Bader Arjen N.
Published: April 2017

Quantitative magnetic resonance imaging (qMRI) is a versatile, non-destructive and non-invasive tool in life, material, and medical sciences. When multiple components contribute to the signal in a single pixel, however, it is difficult to quantify their individual contributions and characteristic parameters. Here we introduce the concept of phasor representation to qMRI to disentangle the signals from multiple components in imaging data. Plotting the phasors allowed for decomposition, unmixing, segmentation and quantification of our in vivo data from a plant stem, a human and mouse brain and a human prostate. In human brain images, we could identify 3 main T
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components and 3 apparent diffusion coefficients; in human prostate 5 main contributing spectral shapes were distinguished. The presented phasor analysis is model-free, fast and accurate. Moreover, we also show that it works for undersampled data.
Temporal dynamics of saccades explained by a self-paced process
Authors: Amit Roy , Abeles Dekel , Bar-Gad Izhar , Yuval-Greenberg Shlomit
Published: April 2017

Sensory organs are thought to sample the environment rhythmically thereby providing periodic perceptual input. Whisking and sniffing are governed by oscillators which impose rhythms on the motor-control of sensory acquisition and consequently on sensory input. Saccadic eye movements are the main visual sampling mechanism in primates, and were suggested to constitute part of such a rhythmic exploration system. In this study we characterized saccadic rhythmicity, and examined whether it is consistent with autonomous oscillatory generator or with self-paced generation. Eye movements were tracked while observers were either free-viewing a movie or fixating a static stimulus. We inspected the temporal dynamics of exploratory and fixational saccades and quantified their first-order and high-order dependencies. Data were analyzed using methods derived from spike-train analysis, and tested against mathematical models and simulations. The findings show that saccade timings are explained by first-order dependencies, specifically by their refractory period. Saccade-timings are inconsistent with an autonomous pace-maker but are consistent with a “self-paced” generator, where each saccade is a link in a chain of neural processes that depend on the outcome of the saccade itself. We propose a mathematical model parsimoniously capturing various facets of saccade-timings, and suggest a possible neural mechanism producing the observed dynamics.