bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling DNA origami self-assembly at the domain level
Authors: Dannenberg Frits , Dunn Katherine E. , Bath Jonathan , Kwiatkowska Marta , Turberfield Andrew J. , Ouldridge Thomas E.
Published: October 2015

We present a modelling framework, and basic model parameterization, for the study of DNA origami folding at the level of DNA domains. Our approach is explicitly kinetic and does not assume a specific folding pathway. The binding of each staple is associated with a free-energy change that depends on staple sequence, the possibility of coaxial stacking with neighbouring domains, and the entropic cost of constraining the scaffold by inserting staple crossovers. A rigorous thermodynamic model is difficult to implement as a result of the complex, multiply connected geometry of the scaffold: we present a solution to this problem for planar origami. Coaxial stacking of helices and entropic terms, particularly when loop closure exponents are taken to be larger than those for ideal chains, introduce interactions between staples. These cooperative interactions lead to the prediction of sharp assembly transitions with notable hysteresis that are consistent with experimental observations. We show that the model reproduces the experimentally observed consequences of reducing staple concentration, accelerated cooling, and absent staples. We also present a simpler methodology that gives consistent results and can be used to study a wider range of systems including non-planar origami.
Chiral effects on helicity studied via the energy landscape of short (d, l)-alanine peptides
Authors: Neelamraju Sridhar , Oakley Mark T. , Johnston Roy L.
Published: October 2015

The homochirality of natural amino acids facilitates the formation of regular secondary structures such as α-helices and β-sheets. Here, we study the relationship between chirality and backbone structure for the example of hexa-alanine. The most stable stereoisomers are identified through global optimisation. Further, the energy landscape, a database of connected low-energy local minima and transition points, is constructed for various neutral and zwitterionic stereoisomers of hexa-alanine. Three order parameters for partial helicity are applied and metric disconnectivity graphs are presented with partial helicity as a metric. We also apply the Zimm-Bragg model to derive average partial helicities for Ace-(l-Ala)6-NHMe, Ace-(d-Ala-l-Ala)3-NHMe, and Ace-(l-Ala)3-(d-Ala)3-NHMe from the database of local minima and compare with previous studies.
Many-body ab initio diffusion quantum Monte Carlo applied to the strongly correlated oxide NiO
Authors: Mitra Chandrima , Krogel Jaron T. , Santana Juan A. , Reboredo Fernando A.
Published: October 2015

We present a many-body diffusion quantum Monte Carlo (DMC) study of the bulk and defect properties of NiO. We find excellent agreement with experimental values, within 0.3%, 0.6%, and 3.5% for the lattice constant, cohesive energy, and bulk modulus, respectively. The quasiparticle bandgap was also computed, and the DMC result of 4.72 (0.17) eV compares well with the experimental value of 4.3 eV. Furthermore, DMC calculations of excited states at the L, Z, and the gamma point of the Brillouin zone reveal a flat upper valence band for NiO, in good agreement with Angle Resolved Photoemission Spectroscopy results. To study defect properties, we evaluated the formation energies of the neutral and charged vacancies of oxygen and nickel in NiO. A formation energy of 7.2 (0.15) eV was found for the oxygen vacancy under oxygen rich conditions. For the Ni vacancy, we obtained a formation energy of 3.2 (0.15) eV under Ni rich conditions. These results confirm that NiO occurs as a p-type material with the dominant intrinsic vacancy defect being Ni vacancy.
Extensional vibration and size-dependent mechanical properties of single-crystal gold nanorods
Authors: Gan Yong , Sun Zheng , Chen Zhen
Published: October 2015

The vibrational responses of single-crystal gold nanorods with different sizes and aspect ratios caused by femtosecond laser heating have been simulated, using a numerical method that integrates the two-temperature model into molecular dynamics. The fundamental extensional periods of nanorods are derived by analyzing the simulated responses of nanorods and then used to determine the elastic modulus of nanorods with the finite element calculations. It is shown that the modulus of nanorods increases and approaches the value of bulk gold with the increasing nanorod width. The dispersion curves for the fundamental extensional mode of nanorods as obtained by the analytical solutions and the finite element analysis are compared, confirming that the extensional periods of nanorods with an aspect ratio as small as ∼2.4 are fairly well described by the theory based on the long-wavelength limit.
Thermodynamic properties and transport coefficients of air thermal plasmas mixed with ablated vapors of Cu and polytetrafluoroethylene
Authors: Zhang JunMin , Lu ChunRong , Guan YongGang , Liu WeiDong
Published: October 2015

Because the fault arc in aircraft electrical system often causes a fire, it is particularly important to analyze its energy and transfer for aircraft safety. The calculation of arc energy requires the basic parameters of the arc. This paper is mainly devoted to the calculations of equilibrium composition, thermodynamic properties (density, molar weight, enthalpy, and specific heat at constant pressure) and transport coefficients (thermal conductivity, electrical conductivity, and viscosity) of plasmas produced by a mixture of air, Cu, and polytetrafluoroethylene under the condition of local thermodynamic equilibrium. The equilibrium composition is determined by solving a system of equations around the number densities of each species. The thermodynamic properties are obtained according to the standard thermodynamic relationships. The transport coefficients are calculated using the Chapman-Enskog approximations. Results are presented in the temperature range from 3000 to 30 000 K for pressures of 0.08 and 0.1 MPa, respectively. The results are more accurate and are reliable reference data for theoretical analysis and computational simulation of the behavior of fault arc.
Modification of electron states in CdTe absorber due to a buffer layer in CdTe/CdS solar cells
Authors: Fedorenko Y. G. , Major J. D. , Pressman A. , Phillips L. J. , Durose K.
Published: October 2015

By application of the ac admittance spectroscopy method, the defect state energy distributions were determined in CdTe incorporated in thin film solar cell structures concluded on ZnO, ZnSe, and ZnS buffer layers. Together with the Mott-Schottky analysis, the results revealed a strong modification of the defect density of states and the concentration of the uncompensated acceptors as influenced by the choice of the buffer layer. In the solar cells formed on ZnSe and ZnS, the Fermi level and the energy position of the dominant deep trap levels were observed to shift closer to the midgap of CdTe, suggesting the mid-gap states may act as recombination centers and impact the open-circuit voltage and the fill factor of the solar cells. For the deeper states, the broadening parameter was observed to increase, indicating fluctuations of the charge on a microscopic scale. Such changes can be attributed to the grain-boundary strain and the modification of the charge trapped at the grain-boundary interface states in polycrystalline CdTe.
A predictive analytic model for high-performance tunneling field-effect transistors approaching non-equilibrium Green's function simulations
Authors: Salazar Ramon B. , Ilatikhameneh Hesameddin , Rahman Rajib , Klimeck Gerhard , Appenzeller Joerg
Published: October 2015

A new compact modeling approach is presented which describes the full current-voltage (I-V) characteristic of high-performance (aggressively scaled-down) tunneling field-effect-transistors (TFETs) based on homojunction direct-bandgap semiconductors. The model is based on an analytic description of two key features, which capture the main physical phenomena related to TFETs: (1) the potential profile from source to channel and (2) the elliptic curvature of the complex bands in the bandgap region. It is proposed to use 1D Poisson's equations in the source and the channel to describe the potential profile in homojunction TFETs. This allows to quantify the impact of source/drain doping on device performance, an aspect usually ignored in TFET modeling but highly relevant in ultra-scaled devices. The compact model is validated by comparison with state-of-the-art quantum transport simulations using a 3D full band atomistic approach based on non-equilibrium Green's functions. It is shown that the model reproduces with good accuracy the data obtained from the simulations in all regions of operation: the on/off states and the n/p branches of conduction. This approach allows calculation of energy-dependent band-to-band tunneling currents in TFETs, a feature that allows gaining deep insights into the underlying device physics. The simplicity and accuracy of the approach provide a powerful tool to explore in a quantitatively manner how a wide variety of parameters (material-, size-, and/or geometry-dependent) impact the TFET performance under any bias conditions. The proposed model presents thus a practical complement to computationally expensive simulations such as the 3D NEGF approach.
Non-linear macro evolution of a dc driven micro atmospheric glow discharge
Authors: Xu S. F. , Zhong X. X.
Published: October 2015

We studied the macro evolution of the micro atmospheric glow discharge generated between a micro argon jet into ambient air and static water. The micro discharge behaves similarly to a complex ecosystem. Non-linear behaviors are found for the micro discharge when the water acts as a cathode, different from the discharge when water behaves as an anode. Groups of snapshots of the micro discharge formed at different discharge currents are captured by an intensified charge-coupled device with controlled exposure time, and each group consisted of 256 images taken in succession. Edge detection methods are used to identify the water surface and then the total brightness is defined by adding up the signal counts over the area of the micro discharge. Motions of the water surface at different discharge currents show that the water surface lowers increasingly rapidly when the water acts as a cathode. In contrast, the water surface lowers at a constant speed when the water behaves as an anode. The light curves are similar to logistic growth curves, suggesting that a self-inhibition process occurs in the micro discharge. Meanwhile, the total brightness increases linearly during the same time when the water acts as an anode. Discharge-water interactions cause the micro discharge to evolve. The charged particle bomb process is probably responsible for the different behaviors of the micro discharges when the water acts as cathode and anode.
Detection of Cu2Zn5SnSe8 and Cu2Zn6SnSe9 phases in co-evaporated Cu2ZnSnSe4 thin-films
Authors: Schwarz Torsten , Marques Miguel A. L. , Botti Silvana , Mousel Marina , Redinger Alex , Siebentritt Susanne , Cojocaru-Mirédin Oana , Raabe Dierk , Choi Pyuck-Pa
Published: October 2015

Cu2ZnSnSe4 thin-films for photovoltaic applications are investigated using combined atom probe tomography and ab initio density functional theory. The atom probe studies reveal nano-sized grains of Cu2Zn5SnSe8 and Cu2Zn6SnSe9 composition, which cannot be assigned to any known phase reported in the literature. Both phases are considered to be metastable, as density functional theory calculations yield positive energy differences with respect to the decomposition into Cu2ZnSnSe4 and ZnSe. Among the conceivable crystal structures for both phases, a distorted zinc-blende structure shows the lowest energy, which is a few tens of meV below the energy of a wurtzite structure. A band gap of 1.1 eV is calculated for both the Cu2Zn5SnSe8 and Cu2Zn6SnSe9 phases. Possible effects of these phases on solar cell performance are discussed.
Analytical modeling of intensity-modulated photovoltage spectroscopic responses of organic bulk-heterojunction solar cells
Authors: Set Ying Ting , Li Bowen , Lim Fang Jeng , Birgersson Erik , Luther Joachim
Published: October 2015

We have derived a closed-form analytical expression for intensity-modulated photovoltage spectroscopic (IMVS) responses of organic bulk-heterojunction (BHJ) solar cells. With the expression, we have predicted the features of the IMVS spectra, extracted physical parameters from the IMVS measurements, quantified the recombination characteristics of the BHJ devices, and compared the IMVS with the transient photovoltage responses. The analytical model has enabled the utilization of the quantitative information that is inherent in the IMVS measurements.
Tuning characteristic of band gap and waveguide in a multi-stub locally resonant phononic crystal plate
Authors: Wang Xiao-Peng , Jiang Ping , Chen Tian-Ning , Zhu Jian
Published: October 2015

In this paper, the tuning characteristics of band gaps and waveguides in a locally resonant phononic crystal structure, consisting of multiple square stubs deposited on a thin homogeneous plate, are investigated. Using the finite element method and supercell technique, the dispersion relationships and power transmission spectra of those structures are calculated. In contrast to a system of one square stub, systems of multiple square stubs show wide band gaps at lower frequencies and an increased quantity of band gaps at higher frequencies. The vibration modes of the band gap edges are analyzed to clarify the mechanism of the generation of the lowest band gap. Additionally, the influence of the stubs arrangement on the band gaps in multi-stub systems is investigated. The arrangements of the stubs were found to influence the band gaps; this is critical to understand for practical applications. Based on this finding, a novel method to form defect scatterers by changing the arrangement of square stubs in a multi-stub perfect phononic crystal plate was developed. Defect bands can be induced by creating defects inside the original complete band gaps. The frequency can then be tuned by changing the defect scatterers’ stub arrangement. These results will help in fabricating devices such as acoustic filters and waveguides whose band frequency can be modulated.
Structural rearrangements preceding dioxygen formation by the water oxidation complex of photosystem II
Authors: Bao Han , Burnap Robert L.
Published: October 2015

Significance

The oxidation of water by photosystem II underpins autotrophic productivity in the Earth’s biosphere and represents a blueprint for developing sustainable, carbon-neutral technologies. Presently, the crucial catalytic steps leading to O
2
formation remain obscure, although high-resolution kinetic and structural information has led to discussion of possible chemical intermediates. By genetically manipulating the inner surface polarity of a protein cavity holding a water cluster adjacent to the catalytic metal center, a previously unobserved intermediate is revealed. The results have implications for the understanding of the natural mechanism as well as the highly desirable biomimetic devices currently envisioned of solar energy production.
Communication and representation of risk in health crises: the influence of framing and group identity / Comunicación en crisis sanitarias y representación del riesgo. La influencia del framing y la identidad grupal
Authors: Idoiaga Nahia , De Montes Lorena Gil , Valencia José-Francisco
Published: October 2015

Based on the Social Representations Theory (SRT) applied to the social construction of risk and the role played by group identities, this study examines the construction of risk created by the mass media in health epidemics. An experimental design with split-ballot questionnaire and 319 participants was used in which message framing (human interest vs. attribution of responsibility) and proximity (high vs. low) were manipulated for a high invulnerability identity (youth) vs. a low invulnerability identity (elderly) population. Results showed that the human interest framing increased the perception of risk, especially when the proximity of the epidemic was high; this effect was explained by people’s emotional response. Furthermore, youth projected the risk towards ‘the other’ in order to protect their invulnerability identity. Finally, we stress the importance of the SRT on a theoretical and applied level for risk communication in health crises.
Evaluating the potential impact of a mobile telemedicine system on coordination of specialty care for patients with complicated oral lesions in Botswana
Authors: Tesfalul Martha , Littman-Quinn Ryan , Antwi Cynthia , Ndlovu Siphiwo , Motsepe Didintle , Phuthego Motsholathebe , Tau Boitumelo , Mohutsiwa-Dibe Neo , Kovarik Carrie
Published: October 2015

Mobile telemedicine involves the use of mobile device (e.g., cell phones, tablets) technology to exchange information to assist in the provision of patient care. Throughout the world, mobile telemedicine initiatives are increasing in number and in scale, but literature on their impact on patient outcomes in low-resource areas is limited. This study explores the potential impact of a mobile oral telemedicine system on the oral health specialty referral system in Botswana. Analysis of 26 eligible cases from June 2012 to July 2013 reveals high diagnosis concordance between dental officers and oral health specialists at 91.3% (21/23) but significant management plan discordance at 64.0% (16/25), over two-thirds of which involved the specialists disagreeing with the referring clinicians about the need for a visit to a specialist. These findings suggest mobile telemedicine can optimize the use of insights and skills of specialists remotely in regions where they are scarce.
Hind limb myology of the ringtail ( Bassariscus astutus ) and the myology of hind foot reversal
Authors: Liu Margaret , Zack Shawn P. , Lucas Lynn , Allen Darien , Fisher Rebecca E.
Published: October 2015

The ringtail ( Bassariscus astutus ) is a widely distributed small carnivorous mammal (Procyonidae) in Mexico and the southwestern United States. As in other procyonids, the ringtail is capable of rotating its hind foot to allow headfirst descent of vertical substrates. The osteological correlates of this process, termed hind foot reversal, are well documented, but potential myological correlates have never been investigated. We present the 1st detailed study of the muscular anatomy of the hind limb of B. astutus , including the 1st muscle maps of the pelvis and pes of any procyonid. Comparison of the hind limb myology of the ringtail with other arctoid carnivorans, including taxa incapable of hind foot reversal, indicates that the muscles responsible for the action of reversal do not differ significantly between nonreversing forms and taxa capable of partial or full reversal. This suggests that specific myological adaptations are not necessary to achieve hind foot reversal. However, increased development of the digital flexors, which maintain a grip while body mass is supported by the hind limb, may characterize taxa that make use of reversed postures. The hind limb myology of members of Procyonidae does not strongly support either morphological or molecular hypotheses of relationship, in part because relatively few differences among members of the family can be documented.
Assessing the Mismatch Between Incubation and Latent Periods for Vector-Borne Diseases: The Case of Sharka
Authors: Rimbaud Loup , Dallot Sylvie , Delaunay Agnès , Borron Sonia , Soubeyrand Samuel , Thébaud Gaël , Jacquot Emmanuel
Published: October 2015

The relative durations of the incubation period (the time between inoculation and symptom expression) and of the latent period (the time between inoculation and infectiousness of the host) are poorly documented for plant diseases. However, the extent of asynchrony between the ends of these two periods (i.e., their mismatch) can be a key determinant of the epidemic dynamics for many diseases and consequently it is of primary interest in the design of disease management strategies. In order to assess this mismatch, an experimental approach was developed and applied using sharka, a severe disease caused by Plum pox virus (PPV, genus Potyvirus, family Potyviridae) affecting trees belonging to the genus Prunus. Leaves of infected young peach trees were used individually as viral sources in aphid-mediated transmission tests carried out at different time points postinoculation in order to bracket symptom onset. By fitting a nonlinear logistic model to the obtained transmission rates, we demonstrated that the first symptoms appear on leaves 1 day before they rapidly become infectious. In addition, among symptomatic leaves, symptom intensity and transmission rate are positively correlated. These results strengthen the conclusion that, under our experimental conditions, incubation and latent periods of PPV infection are almost synchronous.
A Smartphone-based Decision Support Tool Improves Test Performance Concerning Application of the Guidelines for Managing Regional Anesthesia in the Patient Receiving Antithrombotic or Thrombolytic Therapy
Authors: McEvoy Matthew D. , Hand William R. , Stiegler Marjorie P. , DiLorenzo Amy N. , Ehrenfeld Jesse M. , Moran Kenneth R. , Lekowski Robert , Nunnally Mark E. , Manning Erin L. , Shi Yaping , Shotwell Matthew S. , Gupta Rajnish K. , Corey John M. , Schell Randall M.
Published: October 2015

AbstractAbstract

In this multicenter, randomized trial of more than 250 residents and faculty, use of an electronic decision support tool improved adherence to guidelines in a testing environment regarding regional anesthesia and anticoagulation compared with a control group who could freely access the guidelines and any other cognitive aid.

Background

The American Society of Regional Anesthesia and Pain Medicine (ASRA) consensus statement on regional anesthesia in the patient receiving antithrombotic or thrombolytic therapy is the standard for evaluation and management of these patients. The authors hypothesized that an electronic decision support tool (eDST) would improve test performance compared with native physician behavior concerning the application of this guideline.

Methods

Anesthesiology trainees and faculty at 8 institutions participated in a prospective, randomized trial in which they completed a 20-question test involving clinical scenarios related to the ASRA guidelines. The eDST group completed the test using an iOS app programmed to contain decision logic and content of the ASRA guidelines. The control group completed the test by using any resource in addition to the app. A generalized linear mixed-effects model was used to examine the effect of the intervention.

Results

After obtaining institutional review board’s approval and informed consent, 259 participants were enrolled and randomized (eDST = 122; control = 137). The mean score was 92.4 ± 6.6% in the eDST group and 68.0 ± 15.8% in the control group (P < 0.001). eDST use increased the odds of selecting correct answers (7.8; 95% CI, 5.7 to 10.7). Most control group participants (63%) used some cognitive aid during the test, and they scored higher than those who tested from memory alone (76 ± 15% vs. 57 ± 18%, P < 0.001). There was no difference in time to completion of the test (P = 0.15) and no effect of training level (P = 0.56).

Conclusions

eDST use improved application of the ASRA guidelines compared with the native clinician behavior in a testing environment.
The Effect of Temperature on Soft Contact Lens Diameter
Authors: Young Graeme , Potts Matthew , Sulley Anna
Published: October 2015

Purpose:

The diameters of soft contact lenses are conventionally measured at room temperature (RT), however, all soft lenses shrink when raised to eye temperature (ET). The purpose of this study was to evaluate RT to ET shrinkage in a representative sample of contemporary spherical soft contact lenses.

Methods:

Twenty-four reusable and daily disposable lens types (10 hydrogel and 14 silicone hydrogel) in three powers were measured for total diameter at RT (20°C±1°C) and ET (34°C±1°C). Lens diameter measurements were undertaken after equilibration in ISO saline in a temperature controlled lens analyzer (Optimec Ltd, Malvern, UK). Theoretical changes in base curve radii were also calculated.

Results:

All lens types reduced in diameter when raised to ET. The largest mean changes with silicone hydrogel and hydrogel lenses were with Avaria (Δ0.33 mm) and SofLens Daily Disposable (Δ0.69 mm), respectively. The smallest mean changes for silicone hydrogel and hydrogel lenses were with 1-DAY ACUVUE TruEye (Δ0.04 mm) and SofLens 38 (Δ0.11 mm), respectively. There was, however, a wide range in change between the different lenses tested.

Conclusions:

This study has identified the levels of shrinkage in current soft contact lenses. In many cases, these shrinkage levels can be expected to have significant effects on clinical performance.
Functional Gastrointestinal Disorders Dominate Pediatric Gastroenterology Outpatient Practice
Authors: Rouster Audra S. , Karpinski Aryn C. , Silver David , Monagas Javier , Hyman Paul E.
Published: October 2015

Objectives:

Symptom‐based diagnostic criteria have improved recognition and standardization of pediatric functional gastrointestinal disorders (FGIDs). We used Rome 3 diagnostic criteria to determine the prevalence of FGIDs in pediatric gastroenterology clinic. In the process, we developed a diagnostic questionnaire for infants and toddlers.

Methods:

We enrolled new patients ≤18 years referred during 19 months to a pediatric gastroenterology clinic. Subjects or parents completed a demographic survey and a the Questionnaire on Pediatric Gastrointestinal symptoms, Rome 3 Version (if ≥4 years, or a new infant‐toddler questionnaire) before their appointment.

Results:

We acquired data from 976 subjects: 476 boys, 592 white. Of 332 subjects <4 years, 172 (52%) met diagnostic criteria for ≥1 FGIDs. Of 644 subjects ≥4 years, 486 (75%) met diagnostic criteria for ≥1 FGIDs. Thirty one (9%) subjects <4 years and 170 (26%) subjects ≥4 years met the criteria for ≥2 FGIDs. Of the total sample of subjects <4 years, common FGIDs included functional constipation (29%), infant regurgitation (13%), and cyclic vomiting syndrome (10%). Of the total sample of subjects ≥4 years, common FGIDs included irritable bowel syndrome (36%), abdominal migraine (19%), functional constipation (17%), cyclic vomiting syndrome (8%), functional abdominal pain syndrome (7%), aerophagia (7%), and functional dyspepsia (7%).

Conclusions:

More than half of new pediatric gastrointestinal clinic patients met the Rome 3 criteria for ≥1 FGIDs. Satisfying the criteria may facilitate diagnosis on the first visit.
The Performance of Ki-67 Labeling Index in Different Specimen Categories of Invasive Ductal Carcinoma of the Breast Using 2 Scoring Methods
Authors: Al Nemer Areej
Published: October 2015

In breast carcinoma proliferative rate is not only prognostic, but also predictive factor. Ki-67 labeling index (Ki-67 LI) is a superior and more reproducible way to assess proliferation than counting mitoses. There are different Ki-67 LI cut-off values proposed for stratification. The best method of scoring Ki-67 LI is still controversial. Our aim was to test the consensus of Ki-67 LI read in the 2 most common specimens, diagnostic core biopsies (CNB) and surgical excision (SE), first using the hot spot (HS) for counting, and then the average (Av) Ki-67 LI. Cases diagnosed as having invasive duct breast carcinoma on CNB followed by SE over 6 years were recruited (n=96). Ki-67 LI was counted in both specimen types using HS and Av scoring methods. For both methods, agreement between the 2 specimen categories was tested using different cut-off values. Intraobserver reproducibility was also measured for both scoring methods. Ki-67 LI was significantly lower in CNBs compared with SEs (mean difference: −13.3 and −6.3, P<0.001, using HS and Av methods, respectively). The agreement between Ki-67 LI in CNBs and SEs using 10, 14, and 20 as cut-off value was superior when we used Av method (for κ=0.793, 0.814, and 0.745; vs. for HS: κ=0.542, 0.525, and 0.672, respectively). Intraobserver reproducibility ranged from very good to perfect for both methods. Our results suggested that specimen-specific cut-off value should be applied for both scoring methods.
Damsel in distress: captured damselfish prey emit chemical cues that attract secondary predators and improve escape chances
Authors: Lönnstedt Oona M. , McCormick Mark I.
Published: October 2015

In aquatic environments, many prey animals possess damage-released chemical alarm cues that elicit antipredator behaviours in responsive con- and heterospecifics. Despite considerable study, the selective advantage of alarm cues remains unclear. In an attempt to investigate one of the more promising hypotheses concerning the evolution of alarm cues, we examined whether the cue functions in a fashion analogous to the distress vocalizations emitted by many terrestrial animals. Our results suggest that chemical alarm cues in damselfish (
Pomacentridae
) may have evolved to benefit the cue sender by attracting secondary predators who disrupt the predation event, allowing the prey a greater chance to escape. The coral reef piscivore, the dusky dottyback (
Pseudochromis fuscus
), chemically eavesdrops on predation events and uses chemical alarm cues from fish prey (lemon damselfish;
Pomacentrus moluccensis
) in an attempt to find and steal prey from primary predators. Field studies showed that
Ps. fuscus
aggregate at sites where prey alarm cue has been experimentally released. Furthermore, secondary predators attempted to steal captured prey of primary predators in laboratory trials and enhanced prey escape chances by 35–40%. These results are the first, to the best of our knowledge, to demonstrate a mechanism by which marine fish may benefit from the production and release of alarm cues, and highlight the complex and important role that semiochemicals play in marine predator–prey interactions.
Inter-allelic interactions play a major role in microsatellite evolution
Authors: Amos William , Kosanović Danica , Eriksson Anders
Published: October 2015

Microsatellite mutations identified in pedigrees confirm that most changes involve the gain or loss of single repeats. However, an unexpected pattern is revealed when the resulting data are plotted on standardized scales that range from the shortest to longest allele at a locus. Both mutation rate and mutation bias reveal a strong dependency on allele length relative to other alleles at the same locus. We show that models in which alleles mutate independently cannot explain these patterns. Instead, both mutation probability and direction appear to involve interactions between homologues in heterozygous individuals. Simple models in which the longer homologue in heterozygotes is more likely to mutate and/or biased towards contraction readily capture the observed trends. The exact model remains unclear in all its details but inter-allelic interactions are a vital component, implying a link between demographic history and the mode and tempo of microsatellite evolution.
Communal range defence in primates as a public goods dilemma
Authors: Willems Erik P. , Arseneau T. Jean. M. , Schleuning Xenia , van Schaik Carel P.
Published: October 2015

Classic socio-ecological theory holds that the occurrence of aggressive range defence is primarily driven by ecological incentives, most notably by the economic defendability of an area or the resources it contains. While this ecological cost–benefit framework has great explanatory power in solitary or pair-living species, comparative work on group-living primates has always found economic defendability to be a necessary, but not sufficient condition to account for the distribution of effective range defence across the taxon. This mismatch between theory and observation has recently been ascribed to a collective action problem among group members in, what is more informatively viewed as, a public goods dilemma: mounting effective defence of a communal range against intrusions by outgroup conspecifics. We here further develop this framework, and report on analyses at three levels of biological organization: across species, across populations within a single lineage and across groups and individuals within a single population. We find that communal range defence in primates very rarely involves collective actionsensu strictoand that it is best interpreted as the outcome of opportunistic and strategic individual-level decisions. Whether the public good of a defended communal range is produced by solitary, joint or collective action is thus the outcome of the interplay between the unique characteristics of each individual, local and current socio-ecological conditions, and fundamental life-history traits of the species.
Individual participation in intergroup contests is mediated by numerical assessment strategies in black howler and tufted capuchin monkeys
Authors: Van Belle Sarie , Scarry Clara J.
Published: October 2015

Asymmetries in resource-holding potential between opposing groups frequently determine outcomes of intergroup contests. Since both numerical superiority and high intergroup dominance rank may confer competitive advantages, group members should benefit from assessing the relative strength of rivals prior to engaging in defensive displays. However, differences in individual assessment may emerge when cost–benefit trade-offs differ among group members. We examine the influence of numerical superiority and intergroup dominance relationships on individual participation in intergroup encounters in black howler monkeys (Alouatta pigra) and tufted capuchin monkeys (Sapajus nigritus). Black howlers responded with longer vocal displays during encounters with neighbours with an equal number of resident males, while tufted capuchins increased their participation with increasing relative male group size. Within each species, males and females responded similarly to varying numerical odds, suggesting that despite pay-off asymmetries between males and females, both sexes were similarly influenced by numerical asymmetries in deciding to participate in collective group defence. Whereas the outcome of contests among tufted capuchins was determined by relative male group size, reflected in a pronounced intergroup dominance hierarchy, the absence of dominance relationships among black howler groups may have provoked prolonged vocal displays in order to assess rival groups with matching competitive abilities.
Multiple reputation domains and cooperative behaviour in two Latin American communities
Authors: Macfarlan Shane J. , Lyle Henry F.
Published: October 2015

Reputations are a ubiquitous feature of human social life, and a large literature has been dedicated to explaining the relationship between prosocial reputations and cooperation in social dilemmas. However, humans form reputations in domains other than prosociality, such as economic competency that could affect cooperation. To date, no research has evaluated the relative effects of multiple reputation domains on cooperation. To bridge this gap, we analyse how prosocial and competency reputations affect cooperation in two Latin American communities (Bwa Mawego, Dominica, and Pucucanchita, Peru) across a number of social contexts (Dominica: labour contracting, labour exchange and conjugal partnership formation; Peru: agricultural and health advice network size). First, we examine the behavioural correlates of prosocial and competency reputations. Following, we analyse whether prosocial, competency, or both reputation domains explain the flow of cooperative benefits within the two communities. Our analyses suggest that (i) although some behaviours affect both reputation domains simultaneously, each reputation domain has a unique behavioural signature; and (ii) competency reputations affect cooperation across a greater number of social contexts compared to prosocial reputations. Results are contextualized with reference to the social markets in which behaviour is embedded and a call for greater theory development is stressed.
Leadership solves collective action problems in small-scale societies
Authors: Glowacki Luke , von Rueden Chris
Published: October 2015

Observation of leadership in small-scale societies offers unique insights into the evolution of human collective action and the origins of sociopolitical complexity. Using behavioural data from the Tsimane forager-horticulturalists of Bolivia and Nyangatom nomadic pastoralists of Ethiopia, we evaluate the traits of leaders and the contexts in which leadership becomes more institutional. We find that leaders tend to have more capital, in the form of age-related knowledge, body size or social connections. These attributes can reduce the costs leaders incur and increase the efficacy of leadership. Leadership becomes more institutional in domains of collective action, such as resolution of intragroup conflict, where collective action failure threatens group integrity. Together these data support the hypothesis that leadership is an important means by which collective action problems are overcome in small-scale societies.
Evolving the neuroendocrine physiology of human and primate cooperation and collective action
Authors: Trumble Benjamin C. , Jaeggi Adrian V. , Gurven Michael
Published: October 2015

While many hormones play vital roles in facilitating or reinforcing cooperative behaviour, the neurohormones underlying competitive and cooperative behaviours are largely conserved across all mammals. This raises the question of how endocrine mechanisms have been shaped by selection to produce different levels of cooperation in different species. Multiple components of endocrine physiology—from baseline hormone concentrations, to binding proteins, to the receptor sensitivity and specificity—can evolve independently and be impacted by current socio-ecological conditions or individual status, thus potentially generating a wide range of variation within and between species. Here, we highlight several neurohormones and variation in hormone receptor genes associated with cooperation, focusing on the role of oxytocin and testosterone in contexts ranging from parenting and pair-bonding to reciprocity and territorial defence. While the studies reviewed herein describe the current state of the literature with regard to hormonal modulators of cooperation and collective action, there is still a paucity of research on hormonal mechanisms that help facilitate large-scale collective action. We end by discussing several potential areas for future research.
Conservation patterns’ analysis of 18,364 candidate human-specific regulatory sequences revealed two distinct pathways of the human regulatory DNA divergence
Authors: Glinsky Gennadi V.
Published: October 2015

Thousands of candidate human-specific regulatory sequences (HSRS) have been identified, supporting the idea that unique to human phenotypes result from human-specific alterations of genomic regulatory networks. Here, conservation patterns analysis of 18,364 regulatory DNA segments comprising candidate HSRS was carried out using the most recent releases of the reference genomes’ databases of humans and nonhuman primates (NHP) and defining the sequence conservation threshold as the minimum ratio of bases that must remap of 1.00. Present analyses identified 5,535 candidate HSRS defined by either the acceleration of mutation rates on the human lineage or the functional divergence from chimpanzee that are highly conserved in NHP and appear to evolve by the exaptation of ancestral DNA pathway. This pathway seems mechanistically distinct from the evolution of regulatory DNA driven by the species-specific expansion of transposable elements. It is proposed that phenotypic divergence ofHomo sapiensis driven by the evolution of human-specific genomic regulatory networks via at least two mechanistically distinct pathways of creation of divergent sequences of regulatory DNA: i) exaptation of the highly conserved ancestral regulatory DNA segments; ii) human-specific insertions of transposable elements.
Characterization and interpretation of twin related row-matching orientation relationships between Mg2Sn precipitates and the Mg matrix
Authors: Shi Zhang-Zhi , Zhang Wen-Zheng
Published: October 2015

Two irrational orientation relationships (ORs) are newly observed between β-Mg2Sn precipitates and the α-Mg matrix in an aged Mg–Sn-based alloy, namely OR9: [011]β-9//[0 1 {\bar 1} 0]α, (100)β-9about −15.6° from (0001)αand OR10: [0 {\bar 1} {\bar 1}]β-10//[0 1{\bar 1} 0]α, (100)β-10about 4.0° from ({\bar 2} 1 1 0)α. The ORs have a common reciprocal row-matching condition, which shows that rows of diffraction spots parallel tog(1 1{\bar 1})β-9[org({\bar 1} {\bar 1}1)β-10] from lattice β match those parallel tog(2 {\bar 1} {\bar 1} 4)αfrom lattice α. A twin relationship exists between OR9-type and OR10-type precipitates, of which the major side facets, parallel to the twinning plane, are invariably normal to the matching rows in reciprocal space. The reciprocal row matching of diffraction spots is proven to correspond to a real row matching of lattice sites in direct space. The real matching rows of lattice sites lie in the major side facets, resulting in periodically distributed good matching lattice bands in the facets,i.e.a singular interfacial structure. This explains why the irrational ORs are preferred. This study demonstrates an explicit association of geometric lattice matching with the ORs and the morphologies of precipitates developed during a phase transformation.
(5RS)-6H-Spiro[pyrazolo[1,5-c]quinazoline-5,4′-thiochroman]: efficient synthesis under mild conditions, molecular structure and supramolecular assembly
Authors: Quiroga Jairo , Gálvez Jaime , Cobo Justo , Glidewell Christopher
Published: October 2015

Pyrazolo[1,5-c]quinazolines are fused-quinazoline derivatives which have been reported as potential agents against neurological disorders. The normal synthesis routes to these compounds require harsh reaction conditions, long reaction times or multistep sequences. The title compound, C18H15N3S, has been prepared under very mild conditions by condensation of thiochroman-4-one with 5-(2-aminophenyl)-1H-pyrazole, which had itself been prepared by the reaction of hydrazine hydrate with 4-hydroxyquinoline mediated by a brief period of microwave heating. Within the molecule in the crystal structure, the reduced pyrimidine ring adopts an envelope conformation, whereas the thiane ring adopts a half-chair conformation. Molecules are linked into sheets by a combination of one N—H...S hydrogen bond and two independent C—H...π(arene) hydrogen bonds, which utilize the same aryl ring as the acceptor, with one C—H bond donating to each face of the ring. Comparisons are made with some related compounds.
Crystallization and X-ray diffraction analysis of the HMG domain of the chondrogenesis master regulator Sox9 in complex with a ChIP-Seq-identified DNA element
Authors: Vivekanandan Saravanan , Moovarkumudalvan Balasubramanian , Lescar Julien , Kolatkar Prasanna R.
Published: October 2015

Sox9 is a fundamental sex-determining gene and the master regulator of chondrogenesis, and is involved in the development of various vital organs such as testes, kidney, heart and brain, and in skeletal development. Similar to other known Sox transcription factors, Sox9 recognizes and binds DNA with the consensus sequence C(T/A)TTG(T/A)(T/A) through the highly conserved HMG domain. Nonetheless, the molecular basis of the functional specificity of Sox9 in key developmental processes is still unclear. As an initial step towards a mechanistic understanding of Sox9 transcriptional regulation, the current work describes the details of the purification of the mouse Sox9 HMG domain (mSox9HMG), its crystallization in complex with a ChIP-Seq-identified FOXP2 promoter DNA element and the X-ray diffraction data analysis of this complex. The mSox9HMG–FOXP2 promoter DNA complex was crystallized by the hanging-drop vapour-diffusion method using 20% PEG 3350 in 200 mMsodium/potassium phosphate with 100 mMbis-tris propane at pH 8.5. The crystals diffracted to 2.7 Å resolution and the complex crystallized in the tetragonal space groupP41212, with unit-cell parametersa=b= 99.49,c= 45.89 Å. Crystal-packing parameters revealed that asymmetric unit contained one mSox9HMG–FOXP2 promoter DNA complex with an estimated solvent content of 64%.
Teachers’ approaches to multicultural education in Georgian classrooms
Authors: Tabatadze Shalva
Published: October 2015

Purpose

– This paper aims to explore the multicultural education strategies employed by primary school teachers in Georgia.

Design/methodology/approach

– In-depth interviews with 65 primary school teachers were used. The interviews were analyzed using the theoretical framework of multicultural educational approaches defined by James Banks. The approaches used by Georgian teachers were classified into four approaches to multicultural education: contributions, additive, transformation and social action approaches.

Findings

– The research revealed that the majority of teachers use the contributions and additive approaches to multicultural education. The use of the transformation approach by teachers is very rare and only happens if school textbooks, as well as exercises and assignments in the textbooks, provide this opportunity. The social action approach to multicultural education has not been used in primary grades in Georgia. The research revealed that some teachers reject diversity in their classroom as well as the necessity of developing their students’ intercultural sensitivity. These teachers have an informed and conscious approach to not using multicultural approaches in the teaching process. This approach is named by the author as the “inactive action approach”, which is specific to Georgia and is widely used in primary school classes.

Practical implications

– The study has scientific and practical importance. The findings of this study also have practical importance. They can be used for the implementation of teacher education and training programs in Georgia. Consideration of these findings will contribute to the implementation of the National Objectives of General Education and the National Curriculum of Georgia.

Originality/value

– This study makes contribution to the development of the field of multicultural education in Georgia.
The life and times of a senior scholar: an interview with Denise Rousseau
Authors: Moore Karl
Published: October 2015

Purpose

– This paper aims to present an interview of a senior scholar to get their perspectives on the field, its history and future.

Design/methodology/approach

– A semi-structured in-depth interview was conducted.

Findings

– It is one person’s person views, albeit, a person with very considerable success in the field of business studies.

Originality/value

– The interview reflects the changes in business schools over the interviewee’s decades of experience.