bluuebunny/crossref_metadata_2025 huggingface dataset:
Predictions of future grazing season length for European dairy, beef and sheep farms based on regression with bioclimatic variables
Authors: PHELAN P. , MORGAN E. R. , ROSE H. , GRANT J. , O'KIELY P.
Published: October 2015

Grazing season length (GSL) on grassland farms with ruminant production systems can influence farm economics, livestock disease transmission, environmental impact, milk and meat quality, and consumer choice. Bioclimatic variables are biologically meaningful climate variables that may enable predictions of the impact of future climate change on GSL on European farms. The present study investigated the spatial relationship between current GSL (months) measured by EUROSTAT on dairy, beef and sheep farms in 706, 774 and 878 regions, respectively, and bioclimatic variables. A stepwise multiple regression model revealed a highly significant association between observed GSL and bioclimatic variables across Europe. Mean GSL was positively associated with the mean temperature of the coldest quarter and isothermality, and negatively associated with precipitation in the wettest month. Extrapolating these relationships to future climate change scenarios, most European countries were predicted to have a net increase in GSL with the increase being largest (up to 2·5 months) in the north-east of Europe. However, there were also predictions of increased variability between regions and decreases in GSL of up to 1·5 months in some areas such as the west of France, the south-west of Norway and the west coast of Britain. The study quantified and mapped the potential impact of climate change on GSL for dairy, beef and sheep farms across Europe.
Rochinia confusa, a junior synonym ofR. umbonata(Crustacea: Brachyura: Epialtidae) as revealed by ontogenetic changes
Authors: Tavares Marcos , Santana William , Pettan Renata
Published: October 2015

The carapace and chelipeds ornamentation of the deep-water spider crabRochinia umbonata(Stimpson, 1871), from the Western Atlantic undergo very dramatic ontogenetic changes. Since the also deep-water spider crabRochinia confusaTavares, 1991 is differentiated fromR. umbonatamostly on the basis of these characters,R. confusais regarded herein as an ontogenetic stage and, therefore, a junior subjective synonym ofR. umbonata.
Trophic spectrum and feeding pattern of cannonball jellyfish Stomolophus meleagris (Agassiz, 1862) from central Gulf of California
Authors: Álvarez-Tello Francisco J. , López-Martínez Juana , Lluch-Cota Daniel B.
Published: October 2015

The diet and feeding pattern of scyphomedusa Stomolophus meleagris (Rhizostomeae) was studied, by comparing stomach samples from different developmental stages and environmental zooplankton with the aim to determine diet composition, trophic niche breadth, selectivity and feeding overlap of this edible jellyfish species. Samplings were performed during April and December 2010 and in January 2011, in the coastal lagoon Las Guásimas (27°49′–27°54′N 110°40′–110°35′W), central Gulf of California, which consisted of zooplankton tows and jellyfish collections for stomach content. More than 39 prey items were identified in the gut contents (N = 69), from which eight taxa formed over 90% of the total. Fish eggs were considered main prey (58.6%), copepods (10.8%), veliger larvae of gastropod (13.0%) and bivalve (12.7%) were secondary prey while cirriped and decapod larvae were incidental prey (<3%). However, these proportions varied significantly between small, medium and large size classes of medusa as well as number and type of prey increasing as a function of medusa size. Values of Levin's index confirmed S. meleagris is a specialist predator and Pearre's index showed positive selection of fish eggs, gastropods, bivalves and cirripeds while selectivity was negative for copepods and appendicularians. The relative timing of these changes suggests that ontogenetic processes are closely related with shift in the diet, which indicates increasing predation pressure during development of the medusoid stage of this species, thus emphasizing their ecological importance in coastal ecosystems.
Transverse Navigation under the Ellipsoidal Earth Model and its Performance in both Polar and Non-polar areas
Authors: Yao Yi-qing , Xu Xiao-su , Li Yao , Liu Yi-ting , Sun Jin , Tong Jin-wu
Published: October 2015

The transverse navigation system has been designed and developed to solve the challenges of navigation in polar regions. However, considerable theoretical errors are introduced into the system when the spherical Earth model is adopted. To tackle this problem, a transverse navigation mechanism under the ellipsoidal Earth model has been proposed in this research and the application regions of the proposed algorithm are specified and evaluated through error analysis. The analysis shows the presented transverse navigation system works in both polar and part of the non-polar regions. Field tests were conducted to evaluate the navigation performance in Nanjing, a non-polar region. A novel experimental method, where the field test data in mid-latitude areas was used to simulate the real Inertial Measurement Unit (IMU) data and the reference information in polar regions, was adopted to investigate the performance of the proposed algorithm in polar areas. The results show: that in the mid-latitude areas, the presented transverse navigation system achieves the same accuracy as the traditional inertial navigation system and that in polar regions, the proposed transverse mechanism outperforms the traditional method with a much lower error in longitude and yaw.
Environmental Law and the End of the New Deal Order
Authors: Sabin Paul
Published: October 2015

“I don't think there was ever a field of law which developed as explosively and dramatically as environmental law,” David Sive, a pioneering environmental lawyer, declared in a 1982 interview. “It was the great romance.” Along with new state and federal regulatory agencies and more than a dozen major environmental statutes passed in the 1970s, fledgling public interest environmental law firms emerged as a major force in national politics. The most prominent organizations, founded between 1967 and 1971, included the Environmental Defense Fund (EDF), Center for Law and Social Policy (CLASP), Natural Resources Defense Council (NRDC), and the Sierra Club Legal Defense Fund. Public Advocates and the Center for Law in the Public Interest, two California-based firms founded during these same years, also initiated key litigation. These small but powerful legal organizations—all predominantly funded by the Ford Foundation—quickly achieved landmark victories that helped to define the early successes of modern environmentalism. They delayed the Alaskan pipeline for more than 3 years, defeated a Disney resort proposed for the Sierra Nevada mountains, and helped push the pesticide DDT off the market in the United States. The organizations also foiled myriad plans for highways, airports, and power plants and pressed agencies to implement new environmental laws in the 1970s.
Mutual influences between child emotion regulation and parent–child reciprocity support development across the first 10 years of life: Implications for developmental psychopathology
Authors: Feldman Ruth
Published: October 2015

Elucidating the mechanisms by which infant birth conditions shape development across lengthy periods is critical for understanding typical and pathological development and for targeted early interventions. This study examined how newborns' regulatory capacities impact 10-year outcomes via the bidirectional influences of child emotion regulation (ER) and reciprocal parenting across early development. Guided by dynamic systems theory, 125 infants were tested at seven time points: birth, 3, 6, 12, and 24 months and 5 and 10 years. Initial regulatory conditions were measured by respiratory sinus arrhythmia (RSA; vagal tone) and neurobehavioral regulation (Brazelton, 1973) at birth. At each assessment between 3 months and 5 years, infant ER was microcoded from age-appropriate paradigms and mother–child reciprocity observed during social interactions. Four regulation-related outcomes were measured at 10 years: child RSA, empathy measured by mother–child conflict discussion and a lab paradigm, accident proneness, and behavior problems. An autoregressive cross-lagged structural model indicated that infant birth conditions impacted 10-year outcomes via three mechanisms. First, child ER and reciprocal parenting were individually stable across development and were each predicted by regulatory birth conditions, describing gradual maturation of ER and reciprocity over time. Second, better ER skills at one time point were related to greater reciprocity at the next time point and vice versa, and these cross-time effects defined a field of individual-context mutual influences that mediated the links between neonatal RSA and 10-year outcomes. Third, direct associations emerged between neonatal regulation and outcome, suggesting that birth conditions may establish a neurobiological milieu that promotes a more mature and resilient system. These mechanisms describe distinct “attractor” states that constrain the system's future options, emphasize the importance of defining behavior-based phenotypes of heterotypic continuity, and suggest that infants may shape their development by initiating unique cascades of individual-context bidirectional effects.
Social and economic antecedents and consequences of adolescent aggressive personality: Predictions from the interactionist model
Authors: Conger Rand D. , Martin Monica J. , Masarik April S. , Widaman Keith F. , Donnellan M. Brent
Published: October 2015

The present study examined the development of a cohort of 279 early adolescents (52% female) from 1990 to 2005. Guided by the interactionist model of socioeconomic status and human development, we proposed that parent aggressive personality, economic circumstances, interparental conflict, and parenting characteristics would affect the development of adolescent aggressive personality traits. In turn, we hypothesized that adolescent aggressiveness would have a negative influence on adolescent functioning as an adult in terms of economic success, personality development, and close relationships 11 years later. Findings were generally supportive of the interactionist model proposition that social and economic difficulties in the family of origin intensify risk for adolescent aggressive personality (the social causation hypothesis) and that this personality trait impairs successful transition to adult roles (the social selection hypothesis) in a transactional process over time and generations. These results underscore how early development leads to child influences that appear to directly hamper the successful transition to adult roles (statistical main effects) and also amplify the negative impact of dysfunctional family systems on the transition to adulthood (statistical interaction effects). The findings suggest several possible points of intervention that might help to disrupt this negative developmental sequence of events.
Emergent patterns of risk for psychopathology: The influence of infant avoidance and maternal caregiving on trajectories of social reticence
Authors: Degnan Kathryn A. , Hane Amie Ashley , Henderson Heather A. , Walker Olga L. , Ghera Melissa M. , Fox Nathan A.
Published: October 2015

The current study investigated the influential role of infant avoidance on links between maternal caregiving behavior and trajectories at risk for psychopathology. A sample of 153 children, selected for temperamental reactivity to novelty, was followed from infancy through early childhood. At 9 months, infant avoidance of fear-eliciting stimuli in the laboratory and maternal sensitivity at home were assessed. At 36 months, maternal gentle discipline was assessed at home. Children were repeatedly observed in the lab with an unfamiliar peer across early childhood. A latent class growth analysis yielded three longitudinal risk trajectories of social reticence behavior: a high-stable trajectory, a high-decreasing trajectory, and a low-increasing trajectory. For infants displaying greater avoidance, 9-month maternal sensitivity and 36-month maternal gentle discipline were both positively associated with membership in the high-stable social reticence trajectory, compared to the high-decreasing social reticence trajectory. For infants displaying lower avoidance, maternal sensitivity was positively associated with membership in the high-decreasing social reticence trajectory, compared to the low-increasing trajectory. Maternal sensitivity was positively associated with the high-stable social reticence trajectory when maternal gentle discipline was lower. These results illustrate the complex interplay of infant and maternal behavior in early childhood trajectories at risk for emerging psychopathology.
Infant negative reactivity defines the effects of parent–child synchrony on physiological and behavioral regulation of social stress
Authors: Pratt Maayan , Singer Magi , Kanat-Maymon Yaniv , Feldman Ruth
Published: October 2015

How infants shape their own development has puzzled developmentalists for decades. Recent models suggest that infant dispositions, particularly negative reactivity and regulation, affect outcome by determining the extent of parental effects. Here, we used a microanalytic experimental approach and proposed that infants with varying levels of negative reactivity will be differentially impacted by parent–infant synchrony in predicting physiological and behavioral regulation of increasing social stress during an experimental paradigm. One hundred and twenty-two mother–infant dyads (4–6 months) were observed in the face-to-face still face (SF) paradigm and randomly assigned to three experimental conditions: SF with touch, standard SF, and SF with arms’ restraint. Mother–infant synchrony and infant negative reactivity were observed at baseline, and three mechanisms of behavior regulation were microcoded; distress, disengagement, and social regulation. Respiratory sinus arrhythmia baseline, reactivity, and recovery were quantified. Structural equation modeling provided support for our hypothesis. For physiological regulation, infants high in negative reactivity receiving high mother–infant synchrony showed greater vagal withdrawal, which in turn predicted comparable levels of vagal recovery to that of nonreactive infants. In behavioral regulation, only infants low in negative reactivity who received high synchrony were able to regulate stress by employing social engagement cues during the SF phase. Distress was reduced only among calm infants to highly synchronous mothers, and disengagement was lowest among highly reactive infants experiencing high mother–infant synchrony. Findings chart two pathways by which synchrony may bolster regulation in infants of high and low reactivity. Among low reactive infants, synchrony builds a social repertoire for handling interpersonal stress, whereas in highly reactive infants, it constructs a platform for repeated reparation of momentary interactive “failures” and reduces the natural tendency of stressed infants to disengage from source of distress. Implications for the construction of synchrony-focused interventions targeting infants of varying dispositions are discussed.
Emerging psychopathology moderates upward social mobility: The intergenerational (dis)continuity of socioeconomic status
Authors: Véronneau Marie-Hélène , Serbin Lisa A. , Stack Dale M. , Ledingham Jane , Schwartzman Alex E.
Published: October 2015

Socioeconomic status (SES) is relatively stable across generations, but social policies may create opportunities for upward social mobility among disadvantaged populations during periods of economic growth. With respect to expanded educational opportunities that occurred in Québec (Canada) during the 1960s, we hypothesized that children's social and academic competence would promote upward mobility, whereas aggression and social withdrawal would have the opposite effect. Out of 4,109 children attending low-SES schools in 1976–1978, a representative subsample of 503 participants were followed until midadulthood. Path analyses revealed that parents’ SES predicted offspring's SES through associations with offspring's likeability, academic competence, and educational attainment. Interaction effects revealed individual risk factors that moderated children's ability to take advantage of intrafamilial or extrafamilial opportunities that could enhance their educational attainment. Highly aggressive participants and those presenting low academic achievement were unable to gain advantage from having highly educated parents. They reached lower educational attainment than their less aggressive or higher achieving peers who came from a similarly advantaged family background. Growing up with parents occupying low-prestige jobs put withdrawn boys and outgoing girls at risk for low educational attainment. In conclusion, social policies can raise SES across generations, with great benefits for the most disadvantaged segments of the population. However, children presenting with emerging psychopathology or academic weaknesses do not benefit from these policies as much as others, and should receive additional, targeted services.
Bimodal bilingualism: Factors yet to be explored
Authors: TANG GLADYS
Published: October 2015

Recent years have seen increasing research into bimodal bilingualism from a variety of paradigms such as bilingual acquisition, language processing, neural systems, and cognitive skills, with the underlying assumption that successful bimodal bilingualism entails the knowledge representations and processing of two grammars each of which via a distinct modality, auditory-oral versus visual-gestural. As such, it opens up an arena of cutting-edge research enabling comparisons of the linguistic and cognitive effects of monolingualism versus bilingualism, as well as unimodal bilingualism versus bimodal bilingualism.
Day's goby, Acentrogobius dayi Koumans, 1941 (Pisces: Gobiidae) in the desert Sawa Lake, south-west Baghdad, Iraq
Authors: Ziyadi Mustafa S.F. , Jawad Laith A. , Almukhtar Mustafa A. , Pohl Thomas
Published: October 2015

Three adult specimens of the fish speciesAcentrogobius dayiwere collected from Sawa Lake, south-west of Baghdad, Iraq. The current report represents the first record ofA. dayifrom Sawa Lake and from other inland water bodies of Iraq.
Election campaign agendas, government partisanship, and the welfare state
Authors: Jakobsson Niklas , Kumlin Staffan
Published: October 2015

Although theoretically contentious, most empirical studies contend that electoral-political factors structure the welfare state. In practice, most studies concentrate on ‘government partisanship’, that is the ideological character of the government. We agree thatpolitics mattersbut also seek to expand our understanding of what ‘politics’ should be taken to mean. Drawing on recent comparative research on agenda-setting, we study the impact of whether welfare state issues were broadly salient in the public sphere during the election campaign that produced the government. We formulate hypotheses about how suchsystemiccampaign salience and government partisanship (separately and interactively) affect welfare generosity. We also consider how such effects might have changed, taking into account challenges to standard assumptions of representative democracy coming from the ‘new politics of the welfare state’ framework. We combine well-known, but updated, data on welfare state generosity and government partisanship, with original contextual data on campaign salience from 16 West European countries for the years 1980–2008. We find thatcampaigns matterbut also that their impact has changed. During the first half of the examined period (the 1980s and early 1990s), it mainly served tofacilitategovernment partisanship effects on the welfare state. More recently, big-time campaign attention to welfare state issues results in some retrenchment (almost) regardless of who forms the postelection government. This raises concerns about the democratic status of the politics of welfare state reform in Europe.
The Conference of High Contracting Parties to the Fourth Geneva Convention of 17 December 2014 and the duty to ensure respect for international humanitarian law
Authors: Lanz Matthias , Max Emilie , Hoehne Oliver
Published: October 2015

While international humanitarian law envisages the possibility of holding formal thematic discussions, only United Nations General Assembly resolutions prompted the depositary of the Geneva Conventions to consult the High Contracting Parties on the opportuneness of conflict-specific conferences. Recalling the precedents of 1999 and 2001 – convened on the basis of the support expressed by the States Parties during related consultations – this article focuses on the Conference of High Contracting Parties to the Fourth Geneva Convention of 17 December 2014, which is likewise related to the Israeli–Palestinian conflict. The result of the conference consists of a declaration reflecting the willingness of the States Parties to further implement Article 1 common to the four Geneva Conventions.
Ethnic Differences in Correlates of Suicidal Behavior Among Women Seeking Help for Intimate Partner Violence
Authors: Cavanaugh Courtenay E. , Messing Jill T. , Eyzerovich Evelina , Campbell Jacquelyn C.
Published: October 2015

Abstract. Background: Women abused by an intimate partner are at risk of engaging in nonfatal suicidal behavior and suicidal communication (NSBSC). No studies have examined ethnic differences in correlates of NSBSC among abused women. Aims: This secondary data analytic study examined whether correlates of NSBSC previously reported among a mixed ethnic sample of women seeking help for abuse by a male intimate partner differed for those who self-identified as Latina (N = 340), African American (N = 184), or European American (N = 67). Method: Logistic regression was used to examine correlates of NSBSC separately among Latina, African American, and European American women. Results: More severe violence by a male intimate partner, having a chronic or disabling illness, being younger, and being unemployed were positively associated with NSBSC in bivariate analyses among Latina women, but unemployment did not remain significantly associated with NSBSC in the multiple logistic regression. There were no significant correlates of NSBSC for African American women. Having a chronic illness was significantly associated with NSBSC among European American women. Conclusion: Findings suggest the need for culturally tailored suicide prevention interventions and studies that examine risk and protective factors for NSBSC among a diversity of women abused by male intimate partners
Suicide Prevention Through Online Gatekeeping Using Search Advertising Techniques
Authors: Sueki Hajime , Ito Jiro
Published: October 2015

Abstract. Background: Nurturing gatekeepers is an effective suicide prevention strategy. Internet-based methods to screen those at high risk of suicide have been developed in recent years but have not been used for online gatekeeping. Aims: A preliminary study was conducted to examine the feasibility and effects of online gatekeeping. Method: Advertisements to promote e-mail psychological consultation service use among Internet users were placed on web pages identified by searches using suicide-related keywords. We replied to all emails received between July and December 2013 and analyzed their contents. Results: A total of 139 consultation service users were analyzed. The mean age was 23.8 years (SD = 9.7), and female users accounted for 80% of the sample. Suicidal ideation was present in 74.1%, and 12.2% had a history of suicide attempts. After consultation, positive changes in mood were observed in 10.8%, 16.5% showed intentions to seek help from new supporters, and 10.1% of all 139 users actually took help-seeking actions. Conclusion: Online gatekeeping to prevent suicide by placing advertisements on web search pages to promote consultation service use among Internet users with suicidal ideation may be feasible.
Revisiting the Concept of Knowledge
Authors: Labouliere Christa D. , Tarquini Sarah J. , Totura Christine M. W. , Kutash Krista , Karver Marc S.
Published: October 2015

Abstract. Background: Although gatekeeper training is effective at increasing knowledge, some question the effectiveness of these programs due to high pretraining knowledge levels. However, knowledge scores may be artificially inflated when students guess answer options correctly but lack information needed to assist suicidal peers. Aims: To use free-recall questions to evaluate suicide prevention knowledge and compare levels of knowledge using this methodology with established assessment methods in the literature. Method: Free-recall knowledge questions were examined before and after participation in a student gatekeeper training program. Focus groups with students enriched interpretation of quantitative results. Results: Unlike in studies using forced-choice assessment, students’ baseline knowledge was markedly low using free-recall questions and, despite making significant improvement from pretraining levels, posttraining knowledge barely approached passable levels. Focus group findings suggest that training sessions may need to be more engaging and interactive in order to improve knowledge transfer. Conclusion: Free-recall questions may provide a less inflated measure of accessible knowledge learned from school-based suicide prevention curricula. Evaluators and programmatic partners should be cognizant of this methodological issue and consider using a mix of assessment methodologies to determine students’ actual levels of knowledge after participation in gatekeeper training.
Understanding Multiscale Coupled Processes in Shale
Authors: Heath Jason , Ilgen Anastasia
Published: October 2015

Shales at All Scales: Exploring Coupled Processes Workshop; Santa Fe, New Mexico, 9–11 June 2015
Kinesin-5 is a microtubule polymerase
Authors: Chen Yalei , Hancock William O
Published: October 2015

Kinesin-5 slides antiparallel microtubules during spindle assembly, and regulates the branching of growing axons. Besides the mechanical activities enabled by its tetrameric configuration, the specific motor properties of kinesin-5 that underlie its cellular function remain unclear. Here by engineering a stable kinesin-5 dimer and reconstituting microtubule dynamics in vitro, we demonstrate that kinesin-5 promotes microtubule polymerization by increasing the growth rate and decreasing the catastrophe frequency. Strikingly, microtubules growing in the presence of kinesin-5 have curved plus ends, suggesting that the motor stabilizes growing protofilaments. Single-molecule fluorescence experiments reveal that kinesin-5 remains bound to the plus ends of static microtubules for 7 s, and tracks growing microtubule plus ends in a manner dependent on its processivity. We propose that kinesin-5 pauses at microtubule plus ends and enhances polymerization by stabilizing longitudinal tubulin–tubulin interactions, and that these activities underlie the ability kinesin-5 to slide and stabilize microtubule bundles in cells.
Shadows of anyons and the entanglement structure of topological phases
Authors: Haegeman J. , Zauner V. , Schuch N. , Verstraete F.
Published: October 2015

The low-temperature dynamics of quantum systems are dominated by the low-energy eigenstates. For two-dimensional systems in particular, exotic phenomena such as topological order and anyon excitations can emerge. While a complete low-energy description of strongly correlated systems is hard to obtain, essential information about the elementary excitations is encoded in the eigenvalue structure of the quantum transfer matrix. Here we study the transfer matrix of topological quantum systems using the tensor network formalism and demonstrate that topological quantum order requires a particular type of ‘symmetry breaking’ for the fixed point subspace. We also relate physical anyon excitations to domain-wall excitations at the level of the transfer matrix. This formalism enables us to determine the structure of the topological sectors in two-dimensional gapped phases very efficiently, therefore opening novel avenues for studying fundamental questions related to anyon condensation and confinement.
Mechanically activated switching of Si-based single-molecule junction as imaged with three-dimensional dynamic probe
Authors: Nakamura Miki , Yoshida Shoji , Katayama Tomoki , Taninaka Atsushi , Mera Yutaka , Okada Susumu , Takeuchi Osamu , Shigekawa Hidemi
Published: October 2015

Understanding and extracting the full functions of single-molecule characteristics are key factors in the development of future device technologies, as well as in basic research on molecular electronics. Here we report a new methodology for realizing a three-dimensional (3D) dynamic probe of single-molecule conductance, which enables the elaborate 3D analysis of the conformational effect on molecular electronics, by the formation of a Si/single molecule/Si structure using scanning tunnelling microscopy (STM). The formation of robust covalent bonds between a molecule and Si electrodes, together with STM-related techniques, enables the stable and repeated control of the conformational modulation of the molecule. By 3D imaging of the conformational effect on a 1,4-diethynylbenzene molecule, a binary change in conductance with hysteresis is observed for the first time, which is considered to originate from a mechanically activated conformational change.
Terahertz-driven linear electron acceleration
Authors: Nanni Emilio A. , Huang Wenqian R. , Hong Kyung-Han , Ravi Koustuban , Fallahi Arya , Moriena Gustavo , Dwayne Miller R. J. , Kärtner Franz X.
Published: October 2015

The cost, size and availability of electron accelerators are dominated by the achievable accelerating gradient. Conventional high-brightness radio-frequency accelerating structures operate with 30–50 MeV m−1 gradients. Electron accelerators driven with optical or infrared sources have demonstrated accelerating gradients orders of magnitude above that achievable with conventional radio-frequency structures. However, laser-driven wakefield accelerators require intense femtosecond sources and direct laser-driven accelerators suffer from low bunch charge, sub-micron tolerances and sub-femtosecond timing requirements due to the short wavelength of operation. Here we demonstrate linear acceleration of electrons with keV energy gain using optically generated terahertz pulses. Terahertz-driven accelerating structures enable high-gradient electron/proton accelerators with simple accelerating structures, high repetition rates and significant charge per bunch. These ultra-compact terahertz accelerators with extremely short electron bunches hold great potential to have a transformative impact for free electron lasers, linear colliders, ultrafast electron diffraction, X-ray science and medical therapy with X-rays and electron beams.
Neuronal activity regulates remyelination via glutamate signalling to oligodendrocyte progenitors
Authors: Gautier Hélène O. B. , Evans Kimberley A. , Volbracht Katrin , James Rachel , Sitnikov Sergey , Lundgaard Iben , James Fiona , Lao-Peregrin Cristina , Reynolds Richard , Franklin Robin J. M. , Káradóttir Ragnhildur T
Published: October 2015

Myelin regeneration can occur spontaneously in demyelinating diseases such as multiple sclerosis (MS). However, the underlying mechanisms and causes of its frequent failure remain incompletely understood. Here we show, using an in-vivo remyelination model, that demyelinated axons are electrically active and generate de novo synapses with recruited oligodendrocyte progenitor cells (OPCs), which, early after lesion induction, sense neuronal activity by expressing AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid)/kainate receptors. Blocking neuronal activity, axonal vesicular release or AMPA receptors in demyelinated lesions results in reduced remyelination. In the absence of neuronal activity there is a ∼6-fold increase in OPC number within the lesions and a reduced proportion of differentiated oligodendrocytes. These findings reveal that neuronal activity and release of glutamate instruct OPCs to differentiate into new myelinating oligodendrocytes that recover lost function. Co-localization of OPCs with the presynaptic protein VGluT2 in MS lesions implies that this mechanism may provide novel targets to therapeutically enhance remyelination.
Two-photon fluorescence lifetime imaging of primed SNARE complexes in presynaptic terminals and β cells
Authors: Takahashi Noriko , Sawada Wakako , Noguchi Jun , Watanabe Satoshi , Ucar Hasan , Hayashi-Takagi Akiko , Yagishita Sho , Ohno Mitsuyo , Tokumaru Hiroshi , Kasai Haruo
Published: October 2015

It remains unclear how readiness for Ca2+-dependent exocytosis depends on varying degrees of SNARE complex assembly. Here we directly investigate the SNARE assembly using two-photon fluorescence lifetime imaging (FLIM) of Förster resonance energy transfer (FRET) between three pairs of neuronal SNAREs in presynaptic boutons and pancreatic β cells in the islets of Langerhans. These FRET probes functionally rescue their endogenous counterparts, supporting ultrafast exocytosis. We show thattrans-SNARE complexes accumulated in the active zone, and estimate the number of complexes associated with each docked vesicle. In contrast, SNAREs were unassembled in resting state, and assembled only shortly prior to insulin exocytosis, which proceeds slowly. We thus demonstrate that distinct states of fusion readiness are associated with SNARE complex formation. Our FRET/FLIM approaches enable optical imaging of fusion readiness in both live and chemically fixed tissues.
Spin-dependent recombination probed through the dielectric polarizability
Authors: Bayliss Sam L. , Greenham Neil C. , Friend Richard H. , Bouchiat Hélène , Chepelianskii Alexei D
Published: October 2015

Despite residing in an energetically and structurally disordered landscape, the spin degree of freedom remains a robust quantity in organic semiconductor materials due to the weak coupling of spin and orbital states. This enforces spin-selectivity in recombination processes which plays a crucial role in optoelectronic devices, for example, in the spin-dependent recombination of weakly bound electron-hole pairs, or charge-transfer states, which form in a photovoltaic blend. Here, we implement a detection scheme to probe the spin-selective recombination of these states through changes in their dielectric polarizability under magnetic resonance. Using this technique, we access a regime in which the usual mixing of spin-singlet and spin-triplet states due to hyperfine fields is suppressed by microwave driving. We present a quantitative model for this behaviour which allows us to estimate the spin-dependent recombination rate, and draw parallels with the Majorana–Brossel resonances observed in atomic physics experiments.
A Unified Material Description for Light Induced Deformation in Azobenzene Polymers
Authors: Bin Jonghoon , Oates William S.
Published: October 2015

Complex light-matter interactions in azobenzene polymers have limited our understanding of how photoisomerization induces deformation as a function of the underlying polymer network and form of the light excitation. A unified modeling framework is formulated to advance the understanding of surface deformation and bulk deformation of polymer films that are controlled by linear or circularly polarized light or vortex beams. It is shown that dipole forces strongly respond to polarized light in contrast to higher order quadrupole forces that are often used to describe surface relief grating deformation through a field gradient constitutive law. The modeling results and comparisons with a broad range of photomechanical data in the literature suggest that the molecular structure of the azobenzene monomers dramatically influences the photostrictive behavior. The results provide important insight for designing azobenzene monomers within a polymer network to achieve enhanced photo-responsive deformation.
Comparative analysis of pentavalent rotavirus vaccine strains and G8 rotaviruses identified during vaccine trial in Africa
Authors: Heylen Elisabeth , Zeller Mark , Ciarlet Max , Lawrence Jody , Steele Duncan , Van Ranst Marc , Matthijnssens Jelle
Published: October 2015

RotaTeqTM is a pentavalent rotavirus vaccine based on a bovine rotavirus genetic backbone in vitro reassorted with human outer capsid genes. During clinical trials of RotaTeqTM in Sub-Saharan Africa, the vaccine efficacy over a 2-year follow-up was lower against the genotypes contained in the vaccine than against the heterotypic G8P[6] and G8P[1] rotavirus strains of which the former is highly prevalent in Africa. Complete genome analyses of 43 complete rotavirus genomes collected during phase III clinical trials of RotaTeqTM in Sub-Saharan Africa, were conducted to gain insight into the high level of cross-protection afforded by RotaTeqTM against these G8 strains. Phylogenetic analysis revealed the presence of a high number of bovine rotavirus gene segments in these human G8 strains. In addition, we performed an in depth analysis on the individual amino acid level which showed that G8 rotaviruses were more similar to the RotaTeqTM vaccine than non-G8 strains. Because RotaTeqTM possesses a bovine genetic backbone, the high vaccine efficacy against G8 strains might be partially explained by the fact that all these strains contain a complete or partial bovine-like backbone. Altogether, this study supports the hypothesis that gene segments other than VP7 and VP4 play a role in vaccine-induced immunity.
Resolving Anomalies in Predicting Electrokinetic Energy Conversion Efficiencies of Nanofluidic Devices
Authors: Majumder Sagardip , Dhar Jayabrata , Chakraborty Suman
Published: October 2015

We devise a new approach for capturing complex interfacial interactions over reduced length scales, towards predicting electrokinetic energy conversion efficiencies of nanofluidic devices. By embedding several aspects of intermolecular interactions in continuum based formalism, we show that our simple theory becomes capable of representing complex interconnections between electro-mechanics and hydrodynamics over reduced length scales. The predictions from our model are supported by reported experimental data and are in excellent quantitative agreement with molecular dynamics simulations. The present model, thus, may be employed to rationalize the discrepancies between low energy conversion efficiencies of nanofluidic channels that have been realized from experiments and the impractically high energy conversion efficiencies that have been routinely predicted by the existing theories.
Direct Growth and Controlled Coalescence of Thick AlN Template on Micro-circle Patterned Si Substrate
Authors: Tran Binh Tinh , Hirayama Hideki , Maeda Noritoshi , Jo Masafumi , Toyoda Shiro , Kamata Norihiko
Published: October 2015

High-density micro-circle patterned Si substrates were successfully fabricated for the direct overgrowth of thick AlN templates by using NH3 pulsed-flow multilayer AlN growth and epitaxial lateral overgrowth techniques. The experimental results show that an 8-μm-thick AlN template was grown at a very high growth rate on the substrates. The AlN template had full widths at half maximum of 0.23° and 0.37° for the (002) and (102) reflection planes in X-ray diffraction rocking curves. Atomic force microscopy and transmission electron microscopy confirmed that the roughness of the surface was low (3.5 nm) and the dislocation density was very low (1.5 × 108 cm−2 (screw), 3.7 × 108 (edge) cm−2).
Facile Carbon Fixation to Performic Acids by Water-Sealed Dielectric Barrier Discharge
Authors: Kawasaki Mitsuo , Morita Tatsuo , Tachibana Kunihide
Published: October 2015

Carbon fixation refers to the conversion of carbon dioxide (CO2) to organic materials, as commonly performed in nature through photosynthesis by plants and other autotrophic organisms. The creation of artificial carbon fixation processes is one of the greatest challenges for chemistry to solve the critical environmental issue concerning the reduction of CO2 emissions. We have developed an electricity-driven facile CO2 fixation process that yields performic acid, HCO2OH, from CO2 and water at neutral pH by dielectric barrier discharge with an input electric power conversion efficiency of currently 0.2−0.4%. This method offers a promising future technology for artificial carbon fixation on its own and may also be scaled up in combination with e.g., the post-combustion CO2 capture and storage technology.
Kinetic characterization of trans-proteolytic activity of Chikungunya virus capsid protease and development of a FRET-based HTS assay
Authors: Aggarwal Megha , Sharma Rajesh , Kumar Pravindra , Parida Manmohan , Tomar Shailly
Published: October 2015

Chikungunya virus (CHIKV) capsid protein (CVCP) is a serine protease that possesses cis-proteolytic activity essential for the structural polyprotein processing and plays a key role in the virus life cycle. CHIKV being an emerging arthropod-borne pathogenic virus, is a public health concern worldwide. No vaccines or specific antiviral treatment is currently available for chikungunya disease. Thus, it is important to develop inhibitors against CHIKV enzymes to block key steps in viral reproduction. In view of this, CVCP was produced recombinantly and purified to homogeneity. A fluorescence resonance energy transfer (FRET)-based proteolytic assay was developed for high throughput screening (HTS). A FRET peptide substrate (DABCYL-GAEEWSLAIE-EDANS) derived from the cleavage site present in the structural polyprotein of CVCP was used. The assay with a Z’ factor of 0.64 and coefficient of variation (CV) is 8.68% can be adapted to high throughput format for automated screening of chemical libraries to identify CVCP specific protease inhibitors. Kinetic parameters Km and kcat/Km estimated using FRET assay were 1.26 ± 0.34 μM and 1.11 × 103 M−1 sec−1 respectively. The availability of active recombinant CVCP and cost effective fluorogenic peptide based in vitro FRET assay may serve as the basis for therapeutics development against CHIKV.
Xenopus borealis as an alternative source of oocytes for biophysical and pharmacological studies of neuronal ion channels
Authors: Cristofori-Armstrong Ben , Soh Ming S. , Talwar Sahil , Brown Darren L. , Griffin John D. O. , Dekan Zoltan , Stow Jennifer L. , King Glenn F. , Lynch Joseph W. , Rash Lachlan D.
Published: October 2015

For the past 30 years, oocytes from Xenopus laevis have been extensively used to express and characterise ion channels in an easily controlled environment. Here we report the first use of oocytes from the closely related species Xenopus borealis as an alternative expression system for neuronal ion channels. Using the two-electrode voltage-clamp technique, we show that a wide variety of voltage- and ligand-gated ion channels have the same channel properties and pharmacological profiles when expressed in either X. laevis or X. borealis oocytes. Potential advantages of the X. borealis oocytes include a smaller endogenous chloride current and the ability to produce more intense fluorescence signals when studied with voltage-clamp fluorometry. Scanning electron microscopy revealed a difference in vitelline membrane structure between the two species, which may be related to the discrepancy in fluorescence signals observed. We demonstrate that X. borealis oocytes are a viable heterologous system for expression of neuronal ion channels with some potential advantages over X. laevis oocytes for certain applications.
Induction of microglial toll-like receptor 4 by prothrombin kringle-2: a potential pathogenic mechanism in Parkinson’s disease
Authors: Shin Won-Ho , Jeon Min-Tae , Leem Eunju , Won So-Yoon , Jeong Kyoung Hoon , Park Sang-Joon , McLean Catriona , Lee Sung Joong , Jin Byung Kwan , Jung Un Ju , Kim Sang Ryoung
Published: October 2015

Microglia-mediated neuroinflammation may play an important role in the initiation and progression of dopaminergic (DA) neurodegeneration in Parkinson’s disease (PD) and toll-like receptor 4 (TLR4) is essential for the activation of microglia in the adult brain. However, it is still unclear whether patients with PD exhibit an increase in TLR4 expression in the brain and whether there is a correlation between the levels of prothrombin kringle-2 (pKr-2) and microglial TLR4. In the present study, we first observed that the levels of pKr-2 and microglial TLR4 were increased in the substantia nigra (SN) of patients with PD. In rat and mouse brains, intranigral injection of pKr-2, which is not directly toxic to neurons, led to the disruption of nigrostriatal DA projections. Moreover, microglial TLR4 was upregulated in the rat SN and in cultures of the BV-2 microglial cell line after pKr-2 treatment. In TLR4-deficient mice, pKr-2-induced microglial activation was suppressed compared with wild-type mice, resulting in attenuated neurotoxicity. Therefore, our results suggest that pKr-2 may be a pathogenic factor in PD and that the inhibition of pKr-2-induced microglial TLR4 may be protective against degeneration of the nigrostriatal DA systemin vivo.
The C-terminal amyloidogenic peptide contributes to self-assembly of Avibirnavirus viral protease
Authors: Zheng Xiaojuan , Jia Lu , Hu Boli , Sun Yanting , Zhang Yina , Gao Xiangxiang , Deng Tingjuan , Bao Shengjun , Xu Li , Zhou Jiyong
Published: October 2015

Unlike other viral protease, Avibirnavirus infectious bursal disease virus (IBDV)-encoded viral protease VP4 forms unusual intracellular tubule-like structures during viral infection. However, the formation mechanism and potential biological functions of intracellular VP4 tubules remain largely elusive. Here, we show that VP4 can assemble into tubules in diverse IBDV-infected cells. Dynamic analysis show that VP4 initiates the assembly at early stage of IBDV infection and gradually assembles into larger size of fibrils within the cytoplasm and nucleus. Intracellular assembly of VP4 doesn’t involve the host cytoskeleton, other IBDV-encoded viral proteins or vital subcellular organelles. Interestingly, the last C-terminal hydrophobic and amyloidogenic stretch 238YHLAMA243 with two “aggregation-prone” alanine residues was found to be essential for its intracellular self-assembly. The assembled VP4 fibrils show significantly low solubility, subsequently, the deposition of highly assembled VP4 structures ultimately deformed the host cytoskeleton and nucleus, which was potentially associated with IBDV lytic infection. Importantly, the assembly of VP4 significantly reduced the cytotoxicity of protease activity in host cells which potentially prevent the premature cell death and facilitate viral replication. This study provides novel insights into the formation mechanism and biological functions of the Avibirnavirus protease-related fibrils.
Persistence and variation in microstructural design during the evolution of spider silk
Authors: Madurga R. , Blackledge T. A. , Perea B. , Plaza G. R. , Riekel C. , Burghammer M. , Elices M. , Guinea G. , Pérez-Rigueiro J.
Published: October 2015

The extraordinary mechanical performance of spider dragline silk is explained by its highly ordered microstructure and results from the sequences of its constituent proteins. This optimized microstructural organization simultaneously achieves high tensile strength and strain at breaking by taking advantage of weak molecular interactions. However, elucidating how the original design evolved over the 400 million year history of spider silk and identifying the basic relationships between microstructural details and performance have proven difficult tasks. Here we show that the analysis of maximum supercontracted single spider silk fibers using X ray diffraction shows a complex picture of silk evolution where some key microstructural features are conserved phylogenetically while others show substantial variation even among closely related species. This new understanding helps elucidate which microstructural features need to be copied in order to produce the next generation of biomimetic silk fibers.