bluuebunny/crossref_metadata_2025 huggingface dataset:
First Radiocarbon Chronology for Mwoakilloa (Mokil) Atoll, Eastern Caroline Islands, Micronesia
Authors: Poteate Aaron S , Fitzpatrick Scott M , Ayres William S , Thompson Adam
Published: January 2016

Given their sheer number and evidence for long-term prehistoric occupation, atolls occupy a unique position in the peopling of the Pacific. However, they have frequently been overlooked in favor of larger islands due to a host of logistical and other issues. Once viewed as marginal environments, current research is now showing that small islands like these may have been more attractive to settlers than once thought. A new research program in Micronesia is dedicated to examining atolls to better develop baseline chronologies and investigate long-term human adaptations. As part of the initial stage of the project, we present the first radiocarbon dates (n=10) from Mwoakilloa (Mokil) atoll, which support a continuous occupation beginning between 1700–1560 cal BP (2σ). When compared to the settlement of other atoll groups in Micronesia such as the Marshall Islands—along with the nearby high volcanic islands of Pohnpei and Kosrae at approximately 2000–1800 yr ago—the dates from Mwoakilloa suggest a nearly contemporaneous or only slightly later occupation. The recovery of faunal material also demonstrates the translocation of at least two animals (Pacific rat and dog) to the island by humans that was coeval with early settlement. Additionally, there is evidence of landscape transformation in the form of a relatively large artificial mound created by debris and platform accumulation unseen elsewhere in central-eastern Micronesia, but common to atolls. These new dates reinforce the notion that Mwoakilloa and other atolls are integral to understanding prehistoric adaptations across the vast Pacific, though many questions still remain such as to the degree of interaction that occurred with nearby islands and whether settlement was continuous or intermittent through time.
First Radiocarbon Chronology for the Early Iron Age Sites of Central Kazakhstan (Tasmola Culture and Korgantas Period)
Authors: Beisenov Arman Z , Svyatko Svetlana V , Kassenalin Aibar Е , Zhambulatov Kairat А , Duisenbai Daniyar , Reimer Paula J
Published: January 2016

We present the first radiocarbon dates of Early Iron Age sites of central Kazakhstan (in total, 24 dates for 16 recently excavated sites). Archaeologically, the sites have been attributed to the Tasmola culture of the Saka period and later Korgantas phase of the early Hun period. The new accelerator mass spectrometry (AMS) 14C dates suggest that the majority of analyzed Tasmola sites belong to the beginning of the 8th–5th century cal BC, while Korgantas dates to the 4th–2nd century cal BC. This corresponds with the latest archaeological data for the region; however, it is somewhat contrary to the traditional perception of the chronology of the Scythian period in central Kazakhstan. The new dates suggest the beginning of the Early Scythian period in the region in at least the late 9th or 8th century BC rather than 7th century BC according to the traditional approach.
Radiocarbon Dating of Agrarian Terraces by Means of Buried Soils
Authors: Puy Arnald , Balbo Andrea L , Bubenzer Olaf
Published: January 2016

Soils buried under terrace fills have been widely used to date the construction of ancient agrarian terraces. The reliability of the obtained radiocarbon dates entirely depends on the degree of preservation and isolation of the Ab horizons and on the amount of embedded older carbon. To assess these caveats, we analyzed 1414C dates (11 on charred material and 3 on the bulk organic fraction) obtained from buried soils under Andalusi terrace fills in Ricote, Spain (AD 711–1492). The preservation of Ab horizons was assessed through bulk analyses [particle size distribution (PSD), carbon analyses, magnetic susceptibility (Mag Sus)] and statistics [Welch’s ANOVA, MANOVA (Wilk’s lambda) and effect size tests]. The effects of older carbon were quantified through the systematic dating of Ab horizons within the earliest terrace cluster of Ricote. Our results show that (1) Ab horizons were not disturbed nor mixed with the terrace fills above; (2) the dates determined from the bulk organic fraction were statistically significantly older than those provided by the charred material, probably due to the higher stability of the microcharcoal fraction; and (3) the earliest dates measured on charcoal clustered reliably around cal AD 989–1210, suggesting that the first Andalusi irrigated terraces of Ricote were built between the end of the 10th and the beginning of the 13th centuries AD.
Determination of plasma temperature of copper vapour laser
Authors: Namnabat M. , Behrouzinia S. , Moradi A. R. , Khorasani K.
Published: January 2016

The output power and the temperature profile of a copper vapour laser were investigated versus frequency with various kinds of back mirror in its resonator cavity. A semi-experimental method was used for measuring the plasma temperature and obtaining the temperature profile with various back mirrors. The obtained plasma temperature through this method has good agreement with the operational temperature of the laser.
A Late Roman ‘Hall’ at Batten Hanger, West Sussex
Authors: Kenny James , Lyne Malcolm , Magilton John , Buckland Paul
Published: January 2016

Excavation of the latest surviving structures of the villa at Batten Hanger in West Sussex indicates that a large aisled building was demolished in the late fourth or fifth century and replaced by a large hall 31.6 m long by 11.5 m wide, orientated approximately east–west. The survival of pad stones shows this space to have been divided into seven bays, with the more westerly bays screened off by a cross wall. The east wall of the building had collapsed outwards and was largely complete. A coin of Valentinian III suggests that occupation continued at least to the middle of the fifth century. The Supplementary Material available online (http://journals.cambridge.org/bri) contains a detailed presentation of the coin hoard and the pottery assemblages.
GOODNESS-OF-FIT TESTS FOR MULTIVARIATE COPULA-BASED TIME SERIES MODELS
Authors: Berghaus Betina , Bücher Axel
Published: January 2016

In recent years, stationary time series models based on copula functions became increasingly popular in econometrics to model nonlinear temporal and cross-sectional dependencies. Within these models, we consider the problem of testing the goodness-of-fit of the parametric form of the underlying copula. Our approach is based on a dependent multiplier bootstrap and it can be applied to any stationary, strongly mixing time series. The method extends recent i.i.d. results by Kojadinovic et al. (2011) and shares the same computational benefits compared to methods based on a parametric bootstrap. The finite-sample performance of our approach is investigated by Monte Carlo experiments for the case of copula-based Markovian time series models.
The Electoral Fortunes of Taiwan's Green Party: 1996–2012
Authors: FELL DAFYDD , PENG YEN-WEN
Published: January 2016

The Green Party Taiwan (GPT) represents an important case both for scholars of environmental politics but also Taiwanese politics. Established in 1996, it is the oldest Asian green party and is one of the most active parties in the Asia-Pacific Greens network. The party has enjoyed mixed electoral fortunes. After promising early election results, the GPT virtually ceased contesting elections between 2000 and 2005. However, from 2006 the party began a gradual revival in its vote shares. This process culminated in the January 2012 Legislative Yuan election when the GPT surprised many observers by coming fifth in the proportional party vote. Considering the limited resources at the party's disposal this was quite an achievement. In this study, we examine and explain the changing electoral fortunes of the GPT since its establishment in 1996. We are interested to see whether standard theories for explaining small or ecological party success, that have been developed in western Europe, work well in the Taiwan context. Our research is based on a range of new fieldwork conducted between 2012 and 2014. These include in-depth interviews with campaigners and party leaders, focus group sessions with party leaders and candidates, and interviews with party supporters.
Trading in Vain? Investigating the Philippines' Development-oriented National Security and Free Trade Linkages
Authors: MAGCAMIT MICHAEL I.
Published: January 2016

This paper examines the manner through which the Philippine government has utilized free trade in pursuing its development-oriented national security policies and strategies in the twenty-first century. It argues that against the backdrop of uneven economic development being perpetuated by a deeply entrenched oligarchic system and patronage culture, the primary referent of Philippine national security is its diminishing development space. Despite the government rhetoric with regard to the role of inclusive development in enhancing national security, the Philippine political economy remains highly oligarchic and patrimonial. Such a condition has resulted in institutionalized inequality and structural poverty that undermine the country's supposedly development-based security model. The ability of the very few yet very powerful Filipino elites to transform the country into an oligarchipelago underscores the inefficiencies emanating from this type of politico-economic arrangement. In light of this, the paper evaluates the impacts of the Philippines' free trade activities on its overall level of development space by focusing on several crucial aspects of free trade that the government has failed to properly consider. Moreover, it scrutinizes the key factors that affect the utility of free trade for securing and enhancing the Philippines' development space. The paper concludes by arguing that the Philippine government's attempts at linking its development-centric security interests and free trade objectives have resulted not only in the preservation of uneven economic development and but also the further reinforcement of the existing oligarchic system and patronage culture in the country.
The Pendulum Swings: Experiences from the LDP on Democratizing Party Leadership Selection
Authors: WANG YING
Published: January 2016

Empowering the rank and file members in choosing a party leader has become an increasing trend in parliamentary democracies. This study examines the process of adopting more inclusive methods to choose a party leader in the Liberal Democratic Party (LDP) of Japan. The LDP introduced a national primary to elect a leader in 1978. However, this first attempt to open up the party leadership selection was soon replaced by traditional coalition-making politics. In this regard, the LDP is different from most of the Westminster parties that followed a smooth linear process of transferring more power to the rank and file members. This article identifies a ‘swing-back’ effect between 1980 and 1990 in the democratization process of party leadership selection. Working like a pendulum, the LDP did not resume a primary until 1991. It was in 2003 that a nationwide primary became a regular way. This article argues that the discontinuity of reformist actors caused this uncommon swing-back effect. The reformist split in 1976, the sudden death of Masayoshi Ohira, and Kanemaru mediation in 1984 stalled the reforms. Although one finds a similar trend in democratizing party leadership selection outside Europe, the LDP presented an abnormal inactivity and time-lag differences.
Preventing Systematic Circumvention of the SCM Agreement: Beyond the Mandatory/Discretionary Distinction
Authors: JUNG HANEUL , SUH JEONGMEEN
Published: January 2016

Under the prevailing WTO jurisprudence, the mandatory/discretionary distinction is applied to Article 1.1(b) of the SCM Agreement whenever a Member's measure is challenged ‘as such’ pursuant to the SCM Agreement. However, applying the mandatory/discretionary distinction vis-à-vis Article 1.1(b) may render the entire SCM Agreement vulnerable against certain subsidies designed to confer benefits systematically through private intermediaries. In order to prevent such vulnerability, Article 1.1(b) of the SCM Agreement should be construed to cover benefits conferred as consequences of underlying financial contributions, without being limited by the mandatory/discretionary distinction.
How Saturn Alters the Ionosphere of Titan
Authors: Zastrow Mark
Published: January 2016

New research shows that Saturn's powerful magnetic field changes the atmospheric chemistry of its largest moon, Titan.
Steps to Building a No-Tolerance Culture for Sexual Harassment
Authors: Marín-Spiotta Erika , Schneider Blair , Holmes Mary
Published: January 2016

The American Geophysical Union can lead the way in building an environment where sexual and other types of harassment have no place.
Histone deacetylases in monocyte/macrophage development, activation and metabolism: refining HDAC targets for inflammatory and infectious diseases
Authors: Das Gupta Kaustav , Shakespear Melanie R , Iyer Abishek , Fairlie David P , Sweet Matthew J
Published: January 2016

Macrophages have central roles in danger detection, inflammation and host defense, and consequently, these cells are intimately linked to most disease processes. Major advances in our understanding of the development and function of macrophages have recently come to light. For example, it is now clear that tissue‐resident macrophages can be derived from either blood monocytes or through local proliferation of phagocytes that are originally seeded during embryonic development. Metabolic state has also emerged as a major control point for macrophage activation phenotypes. Herein, we review recent literature linking the histone deacetylase (HDAC) family of enzymes to macrophage development and activation, particularly in relation to these recent developments. There has been considerable interest in potential therapeutic applications for small molecule inhibitors of HDACs (HDACi), not only for cancer, but also for inflammatory and infectious diseases. However, the enormous range of molecular and cellular processes that are controlled by different HDAC enzymes presents a potential stumbling block to clinical development. We therefore present examples of how classical HDACs control macrophage functions, roles of specific HDACs in these processes and approaches for selective targeting of drugs, such as HDACi, to macrophages. Development of selective inhibitors of macrophage‐expressed HDACs and/or selective delivery of pan HDACi to macrophages may provide avenues for enhancing efficacy of HDACi in therapeutic applications, while limiting unwanted side effects.
Orbital angular momentum photonic quantum interface
Authors: Zhou Zhi-Yuan , Li Yan , Ding Dong-Sheng , Zhang Wei , Shi Shuai , Shi Bao-Sen , Guo Guang-Can
Published: January 2016

Light-carrying orbital angular momentum (OAM) has great potential in enhancing the information channel capacity in both classical and quantum optical communications. Long distance optical communication requires the wavelengths of light are situated in the low-loss communication windows, but most quantum memories currently being developed for use in a quantum repeater work at different wavelengths, so a quantum interface to bridge the wavelength gap is necessary. So far, such an interface for OAM-carried light has not been realized yet. Here, we report the first experimental realization of a quantum interface for a heralded single photon carrying OAM using a nonlinear crystal in an optical cavity. The spatial structures of input and output photons exhibit strong similarity. More importantly, single-photon coherence is preserved during up-conversion as demonstrated.
Defective DNA single-strand break repair is responsible for senescence and neoplastic escape of epithelial cells
Authors: Nassour Joe , Martien Sébastien , Martin Nathalie , Deruy Emeric , Tomellini Elisa , Malaquin Nicolas , Bouali Fatima , Sabatier Laure , Wernert Nicolas , Pinte Sébastien , Gilson Eric , Pourtier Albin , Pluquet Olivier , Abbadie Corinne
Published: January 2016

The main characteristic of senescence is its stability which relies on the persistence of DNA damage. We show that unlike fibroblasts, senescent epithelial cells do not activate an ATM-or ATR-dependent DNA damage response (DDR), but accumulate oxidative-stress-induced DNA single-strand breaks (SSBs). These breaks remain unrepaired because of a decrease in PARP1 expression and activity. This leads to the formation of abnormally large and persistent XRCC1 foci that engage a signalling cascade involving the p38MAPK and leading to p16 upregulation and cell cycle arrest. Importantly, the default in SSB repair also leads to the emergence of post-senescent transformed and mutated precancerous cells. In human-aged skin, XRCC1 foci accumulate in the epidermal cells in correlation with a decline of PARP1, whereas DDR foci accumulate mainly in dermal fibroblasts. These findings point SSBs as a DNA damage encountered by epithelial cells with aging which could fuel the very first steps of carcinogenesis.
Non-random walk diffusion enhances the sink strength of semicoherent interfaces
Authors: Vattré A. , Jourdan T. , Ding H. , Marinica M.-C. , Demkowicz M. J.
Published: January 2016

Clean, safe and economical nuclear energy requires new materials capable of withstanding severe radiation damage. One strategy of imparting radiation resistance to solids is to incorporate into them a high density of solid-phase interfaces capable of absorbing and annihilating radiation-induced defects. Here we show that elastic interactions between point defects and semicoherent interfaces lead to a marked enhancement in interface sink strength. Our conclusions stem from simulations that integrate first principles, object kinetic Monte Carlo and anisotropic elasticity calculations. Surprisingly, the enhancement in sink strength is not due primarily to increased thermodynamic driving forces, but rather to reduced defect migration barriers, which induce a preferential drift of defects towards interfaces. The sink strength enhancement is highly sensitive to the detailed character of interfacial stresses, suggesting that ‘super-sink’ interfaces may be designed by optimizing interface stress fields. Such interfaces may be used to create materials with unprecedented resistance to radiation-induced damage.
Emergence of core–peripheries in networks
Authors: Verma T. , Russmann F. , Araújo N.A.M. , Nagler J. , Herrmann H.J.
Published: January 2016

A number of important transport networks, such as the airline and trade networks of the world, exhibit a characteristic core–periphery structure, wherein a few nodes are highly interconnected and the rest of the network frays into a tree. Mechanisms underlying the emergence of core–peripheries, however, remain elusive. Here, we demonstrate that a simple pruning process based on removal of underutilized links and redistribution of loads can lead to the emergence of core–peripheries. Links are assumed beneficial if they either carry a sufficiently large load or are essential for global connectivity. This incentivized redistribution process is controlled by a single parameter, which balances connectivity and profit. The obtained networks exhibit a highly resilient and connected core with a frayed periphery. The balanced network shows a higher resilience than the world airline network or the world trade network, revealing a pathway towards robust structural features through pruning.
Non-CG DNA methylation is a biomarker for assessing endodermal differentiation capacity in pluripotent stem cells
Authors: Butcher Lee M. , Ito Mitsuteru , Brimpari Minodora , Morris Tiffany J. , Soares Filipa A. C. , Ährlund-Richter Lars , Carey Nessa , Vallier Ludovic , Ferguson-Smith Anne C. , Beck Stephan
Published: January 2016

Non-CG methylation is an unexplored epigenetic hallmark of pluripotent stem cells. Here we report that a reduction in non-CG methylation is associated with impaired differentiation capacity into endodermal lineages. Genome-wide analysis of 2,670 non-CG sites in a discovery cohort of 25 phenotyped human induced pluripotent stem cell (hiPSC) lines revealed unidirectional loss (Δβ=13%, P<7.4 × 10−4) of non-CG methylation that correctly identifies endodermal differentiation capacity in 23 out of 25 (92%) hiPSC lines. Translation into a simplified assay of only nine non-CG sites maintains predictive power in the discovery cohort (Δβ=23%, P<9.1 × 10−6) and correctly identifies endodermal differentiation capacity in nine out of ten pluripotent stem cell lines in an independent replication cohort consisting of hiPSCs reprogrammed from different cell types and different delivery systems, as well as human embryonic stem cell (hESC) lines. This finding infers non-CG methylation at these sites as a biomarker when assessing endodermal differentiation capacity as a readout.
The Hippo signalling pathway maintains quiescence in Drosophila neural stem cells
Authors: Ding Rouven , Weynans Kevin , Bossing Torsten , Barros Claudia S. , Berger Christian
Published: January 2016

Stem cells control their mitotic activity to decide whether to proliferate or to stay in quiescence. Drosophila neural stem cells (NSCs) are quiescent at early larval stages, when they are reactivated in response to metabolic changes. Here we report that cell-contact inhibition of growth through the canonical Hippo signalling pathway maintains NSC quiescence. Loss of the core kinases hippo or warts leads to premature nuclear localization of the transcriptional co-activator Yorkie and initiation of growth and proliferation in NSCs. Yorkie is necessary and sufficient for NSC reactivation, growth and proliferation. The Hippo pathway activity is modulated via inter-cellular transmembrane proteins Crumbs and Echinoid that are both expressed in a nutrient-dependent way in niche glial cells and NSCs. Loss of crumbs or echinoid in the niche only is sufficient to reactivate NSCs. Finally, we provide evidence that the Hippo pathway activity discriminates quiescent from non-quiescent NSCs in the Drosophila nervous system.
Climate change not to blame for late Quaternary megafauna extinctions in Australia
Authors: Saltré Frédérik , Rodríguez-Rey Marta , Brook Barry W. , Johnson Christopher N , Turney Chris S. M. , Alroy John , Cooper Alan , Beeton Nicholas , Bird Michael I. , Fordham Damien A. , Gillespie Richard , Herrando-Pérez Salvador , Jacobs Zenobia , Miller Gifford H. , Nogués-Bravo David , Prideaux Gavin J. , Roberts Richard G. , Bradshaw Corey J. A.
Published: January 2016

Late Quaternary megafauna extinctions impoverished mammalian diversity worldwide. The causes of these extinctions in Australia are most controversial but essential to resolve, because this continent-wide event presaged similar losses that occurred thousands of years later on other continents. Here we apply a rigorous metadata analysis and new ensemble-hindcasting approach to 659 Australian megafauna fossil ages. When coupled with analysis of several high-resolution climate records, we show that megafaunal extinctions were broadly synchronous among genera and independent of climate aridity and variability in Australia over the last 120,000 years. Our results reject climate change as the primary driver of megafauna extinctions in the world’s most controversial context, and instead estimate that the megafauna disappeared Australia-wide ∼13,500 years after human arrival, with shorter periods of coexistence in some regions. This is the first comprehensive approach to incorporate uncertainty in fossil ages, extinction timing and climatology, to quantify mechanisms of prehistorical extinctions.
Scrutinizing the double superconducting gaps and strong coupling pairing in (Li1−xFex)OHFeSe
Authors: Du Zengyi , Yang Xiong , Lin Hai , Fang Delong , Du Guan , Xing Jie , Yang Huan , Zhu Xiyu , Wen Hai-Hu
Published: January 2016

In the field of iron-based superconductors, one of the frontier studies is about the pairing mechanism. The recently discovered (Li1−xFex)OHFeSe superconductor with the transition temperature of about 40 K provides a good platform to check the origin of double superconducting gaps and high transition temperature in the monolayer FeSe thin film. Here we report a scanning tunnelling spectroscopy study on the (Li1−xFex)OHFeSe single crystals. The tunnelling spectrum mimics that of the monolayer FeSe thin film and shows double gaps at about 14.3 and 8.6 meV. Further analysis based on the quasiparticle interference allows us to rule out the d-wave gap, and for the first time assign the larger (smaller) gap to the outer (inner) Fermi pockets (after folding) associating with the dxy (dxz/dyz) orbitals, respectively. The gap ratio amounts to 8.7, which demonstrates the strong coupling mechanism in the present superconducting system.
Sequential slip transfer of mixed-character dislocations across Σ3 coherent twin boundary in FCC metals: a concurrent atomistic-continuum study
Authors: Xu Shuozhi , Xiong Liming , Chen Youping , McDowell David L
Published: January 2016

Sequential slip transfer across grain boundaries (GB) has an important role in size-dependent propagation of plastic deformation in polycrystalline metals. For example, the Hall–Petch effect, which states that a smaller average grain size results in a higher yield stress, can be rationalised in terms of dislocation pile-ups against GBs. In spite of extensive studies in modelling individual phases and grains using atomistic simulations, well-accepted criteria of slip transfer across GBs are still lacking, as well as models of predicting irreversible GB structure evolution. Slip transfer is inherently multiscale since both the atomic structure of the boundary and the long-range fields of the dislocation pile-up come into play. In this work, concurrent atomistic-continuum simulations are performed to study sequential slip transfer of a series of curved dislocations from a given pile-up on Σ3 coherent twin boundary (CTB) in Cu and Al, with dominant leading screw character at the site of interaction. A Frank-Read source is employed to nucleate dislocations continuously. It is found that subject to a shear stress of 1.2 GPa, screw dislocations transfer into the twinned grain in Cu, but glide on the twin boundary plane in Al. Moreover, four dislocation/CTB interaction modes are identified in Al, which are affected by (1) applied shear stress, (2) dislocation line length, and (3) dislocation line curvature. Our results elucidate the discrepancies between atomistic simulations and experimental observations of dislocation-GB reactions and highlight the importance of directly modeling sequential dislocation slip transfer reactions using fully 3D models.
Mitochondrial Dysfunction may explain symptom variation in Phelan-McDermid Syndrome
Authors: Frye Richard E. , Cox Devin , Slattery John , Tippett Marie , Kahler Stephen , Granpeesheh Doreen , Damle Shirish , Legido Agustin , Goldenthal Michael J.
Published: January 2016

Phelan-McDermid Syndrome (PMS), which is defined by a deletion within 22q13, demonstrates significant phenotypic variation. Given that six mitochondrial genes are located within 22q13, including complex I and IV genes, we hypothesize that mitochondrial complex activity abnormalities may explain phenotypic variation in PMS symptoms. Complex I, II, II + III and IV activity was measured in 51 PMS participants. Caretakers completed questionnaires and provided genetic information through the PMS foundation registry. Complex activity was abnormal in 59% of PMS participants. Abnormalities were found in complex I and IV but not complex II + III and II activity, consistent with disruption of genes within the 22q13 region. However, complex activity abnormalities were not related to specific gene deletions suggesting a “neighboring effect” of regional deletions on adjacent gene expression. A specific combination of symptoms (autism spectrum disorder, developmental regression, failure-to-thrive, exercise intolerance/fatigue) was associated with complex activity abnormalities. 64% of 106 individuals in the PMS foundation registry who did not have complex activity measured also endorsed this pattern of symptoms. These data suggest that mitochondrial abnormalities, specifically abnormalities in complex I and IV activity, may explain some phenotypic variation in PMS individuals. These results point to novel pathophysiology mechanisms and treatment targets for PMS patients.
Weak phonon scattering effect of twin boundaries on thermal transmission
Authors: Dong Huicong , Xiao Jianwei , Melnik Roderick , Wen Bin
Published: January 2016

To study the effect of twin boundaries on thermal transmission, thermal conductivities of twinned diamond with different twin thicknesses have been studied by NEMD simulation. Results indicate that twin boundaries show a weak phonon scattering effect on thermal transmission, which is only caused by the additional twin boundaries’ thermal resistance. Moreover, according to phonon kinetic theory, this weak phonon scattering effect of twin boundaries is mainly caused by a slightly reduced average group velocity.
Localised excitation of a single photon source by a nanowaveguide
Authors: Geng Wei , Manceau Mathieu , Rahbany Nancy , Sallet Vincent , De Vittorio Massimo , Carbone Luigi , Glorieux Quentin , Bramati Alberto , Couteau Christophe
Published: January 2016

Nowadays, integrated photonics is a key technology in quantum information processing (QIP) but achieving all-optical buses for quantum networks with efficient integration of single photon emitters remains a challenge. Photonic crystals and cavities are good candidates but do not tackle how to effectively address a nanoscale emitter. Using a nanowire nanowaveguide, we realise an hybrid nanodevice which locally excites a single photon source (SPS). The nanowire acts as a passive or active sub-wavelength waveguide to excite the quantum emitter. Our results show that localised excitation of a SPS is possible and is compared with free-space excitation. Our proof of principle experiment presents an absolute addressing efficiency ηa ~ 10−4 only ~50% lower than the one using free-space optics. This important step demonstrates that sufficient guided light in a nanowaveguide made of a semiconductor nanowire is achievable to excite a single photon source. We accomplish a hybrid system offering great potentials for electrically driven SPSs and efficient single photon collection and detection, opening the way for optimum absorption/emission of nanoscale emitters. We also discuss how to improve the addressing efficiency of a dipolar nanoscale emitter with our system.
Equilibration and nonclassicality of a double-well potential
Authors: Campbell Steve , De Chiara Gabriele , Paternostro Mauro
Published: January 2016

A double well loaded with bosonic atoms represents an ideal candidate to simulate some of the most interesting aspects in the phenomenology of thermalisation and equilibration. Here we report an exhaustive analysis of the dynamics and steady state properties of such a system locally in contact with different temperature reservoirs. We show that thermalisation only occurs ‘accidentally’. We further examine the nonclassical features and energy fluxes implied by the dynamics of the double-well system, thus exploring its finite-time thermodynamics in relation to the settlement of nonclassical correlations between the wells.
The sequence to hydrogenate coronene cations: A journey guided by magic numbers
Authors: Cazaux Stéphanie , Boschman Leon , Rougeau Nathalie , Reitsma Geert , Hoekstra Ronnie , Teillet-Billy Dominique , Morisset Sabine , Spaans Marco , Schlathölter Thomas
Published: January 2016

The understanding of hydrogen attachment to carbonaceous surfaces is essential to a wide variety of research fields and technologies such as hydrogen storage for transportation, precise localization of hydrogen in electronic devices and the formation of cosmic H2. For coronene cations as prototypical Polycyclic Aromatic Hydrocarbon (PAH) molecules, the existence of magic numbers upon hydrogenation was uncovered experimentally. Quantum chemistry calculations show that hydrogenation follows a site-specific sequence leading to the appearance of cations having 5, 11, or 17 hydrogen atoms attached, exactly the magic numbers found in the experiments. For these closed-shell cations, further hydrogenation requires appreciable structural changes associated with a high transition barrier. Controlling specific hydrogenation pathways would provide the possibility to tune the location of hydrogen attachment and the stability of the system. The sequence to hydrogenate PAHs, leading to PAHs with magic numbers of H atoms attached, provides clues to understand that carbon in space is mostly aromatic and partially aliphatic in PAHs. PAH hydrogenation is fundamental to assess the contribution of PAHs to the formation of cosmic H2.
Quantitative Analysis of Global Proteome and Lysine Acetylome Reveal the Differential Impacts of VPA and SAHA on HL60 Cells
Authors: Zhu Xiaoyu , Liu Xin , Cheng Zhongyi , Zhu Jun , Xu Lei , Wang Fengsong , Qi Wulin , Yan Jiawei , Liu Ning , Sun Zimin , Liu Huilan , Peng Xiaojun , Hao Yingchan , Zheng Nan , Wu Quan
Published: January 2016

Valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA) are both HDAC inhibitors (HDACi). Previous studies indicated that both inhibitors show therapeutic effects on acute myeloid leukaemia (AML), while the differential impacts of the two different HDACi on AML treatment still remains elusive. In this study, using 3-plex SILAC based quantitative proteomics technique, anti-acetyllysine antibody based affinity enrichment, high resolution LC-MS/MS and intensive bioinformatic analysis, the quantitative proteome and acetylome in SAHA and VPA treated AML HL60 cells were extensively studied. In total, 5,775 proteins and 1,124 lysine acetylation sites were successfully obtained in response to VAP and SAHA treatment. It is found that VPA and SAHA treatment differently induced proteome and acetylome profiling in AML HL60 cells. This study revealed the differential impacts of VPA and SAHA on proteome/acetylome in AML cells, deepening our understanding of HDAC inhibitor mediated AML therapeutics.
Growth control of oxygen stoichiometry in homoepitaxial SrTiO3 films by pulsed laser epitaxy in high vacuum
Authors: Lee Ho Nyung , Ambrose Seo Sung S. , Choi Woo Seok , Rouleau Christopher M.
Published: January 2016

In many transition metal oxides, oxygen stoichiometry is one of the most critical parameters that plays a key role in determining the structural, physical, optical and electrochemical properties of the material. However, controlling the growth to obtain high quality single crystal films having the right oxygen stoichiometry, especially in a high vacuum environment, has been viewed as a challenge. In this work, we show that, through proper control of the plume kinetic energy, stoichiometric crystalline films can be synthesized without generating oxygen defects even in high vacuum. We use a model homoepitaxial system of SrTiO3 (STO) thin films on single crystal STO substrates. Physical property measurements indicate that oxygen vacancy generation in high vacuum is strongly influenced by the energetics of the laser plume and it can be controlled by proper laser beam delivery. Therefore, our finding not only provides essential insight into oxygen stoichiometry control in high vacuum for understanding the fundamental properties of STO-based thin films and heterostructures, but expands the utility of pulsed laser epitaxy of other materials as well.
The duality principle in the presence of postselection
Authors: Leach Jonathan , Bolduc Eliot , Miatto Filippo M. , Piché Kevin , Leuchs Gerd , Boyd Robert W.
Published: January 2016

The duality principle, a cornerstone of quantum mechanics, limits the coexistence of wave and particle behaviours of quantum systems. This limitation takes a quantitative form when applied to the visibility "Equation missing" of interference fringes and predictability "Equation missing" of paths within a two-alternative system, which are bound by the inequality "Equation missing". However, if such a system is coupled to its environment, it becomes possible to obtain conditional measures of visibility and predictability, i.e. measures that are conditioned on the state of the environment. We show that in this case, the predictability and visibility values can lead to an apparent violation of the duality principle. We experimentally realize this apparent violation in a controlled manner by enforcing a fair-sampling-like loophole via postselection. This work highlights some of the subtleties that one can encounter while interpreting familiar quantities such as which-alternative information and visibility. While we concentrated on an extreme example, it is of utmost importance to realise that such subtleties might also be present in cases where the results are not obviously violating an algebraic bound, making them harder (but not any less crucial) to detect.
Phase-Controlled Iron Oxide Nanobox Deposited on Hierarchically Structured Graphene Networks for Lithium Ion Storage and Photocatalysis
Authors: Yun Sol , Lee Young-Chul , Park Ho Seok
Published: January 2016

The phase control, hierarchical architecturing and hybridization of iron oxide is important for achieving multifunctional capability for many practical applications. Herein, hierarchically structured reduced graphene oxide (hrGO)/α-Fe2O3 and γ-Fe3O4 nanobox hybrids (hrGO/α-Fe and hrGO/γ-Fe NBhs) are synthesized via a one-pot, hydrothermal process and their functionality controlled by the crystalline phases is adapted for energy storage and photocatalysis. The three-dimensionally (3D) macroporous structure of hrGO/α-Fe NBhs is constructed, while α-Fe2O3 nanoboxes (NBs) in a proximate contact with the hrGO surface are simultaneously grown during a hydrothermal treatment. The discrete α-Fe2O3 NBs are uniformly distributed on the surface of the hrGO/α-Fe and confined in the 3D architecture, thereby inhibiting the restacking of rGO. After the subsequent phase transition into γ-Fe3O4, the hierarchical structure and the uniform distribution of NBs are preserved. Despite lower initial capacity, the hrGO/α-Fe NBhs show better rate and cyclic performances than those of commercial rGO/α-Fe due to the uniform distribution of discrete α-Fe2O3 NBs and electronic conductivity, macroporosity and buffering effect of the hrGO for lithium ion battery anodes. Moreover, the catalytic activity and kinetics of hrGO/γ-Fe NBhs are enhanced for photo-Fenton reaction because of the uniform distribution of discrete γ-Fe3O4 NBs on the 3D hierarchical architecture.
Camouflage predicts survival in ground-nesting birds
Authors: Troscianko Jolyon , Wilson-Aggarwal Jared , Stevens Martin , Spottiswoode Claire N.
Published: January 2016

Evading detection by predators is crucial for survival. Camouflage is therefore a widespread adaptation, but despite substantial research effort our understanding of different camouflage strategies has relied predominantly on artificial systems and on experiments disregarding how camouflage is perceived by predators. Here we show for the first time in a natural system, that survival probability of wild animals is directly related to their level of camouflage as perceived by the visual systems of their main predators. Ground-nesting plovers and coursers flee as threats approach and their clutches were more likely to survive when their egg contrast matched their surrounds. In nightjars – which remain motionless as threats approach – clutch survival depended on plumage pattern matching between the incubating bird and its surrounds. Our findings highlight the importance of pattern and luminance based camouflage properties and the effectiveness of modern techniques in capturing the adaptive properties of visual phenotypes.
An experimental proposal to test the physical effect of the vector potential
Authors: Wang Rui-Feng
Published: January 2016

There are two interpretations of the Aharonov–Bohm (A–B) effect. One interpretation asserts that the A–B effect demonstrates that the vector potential is a physical reality that can result in the phase shift of a moving charge in quantum mechanics. The other interpretation asserts that the phase shift of the moving charge results from the interaction energy between the electromagnetic field of the moving charge and external electromagnetic fields. This paper briefly reviews these two interpretations and analyzes their differences. In addition, a new experimental scheme is proposed to determine which interpretation is correct.
New α-glucosidase inhibitors from marine algae-derived Streptomyces sp. OUCMDZ-3434
Authors: Chen Zhengbo , Hao Jiejie , Wang Liping , Wang Yi , Kong Fandong , Zhu Weiming
Published: January 2016

Wailupemycins H (1) and I (2) with a new skeleton coupled two 6-(2-phenylnaphthalene-1-yl)pyrane-2-one nuclei to a –CH2– linkage were identified from the culture of Streptomyces sp. OUCMDZ-3434 associated with the marine algae, Enteromorpha prolifera. Compounds 1 and 2 are two new α-glucosidase inhibitors with the Ki/IC50 values of 16.8/19.7 and 6.0/8.3 μM, respectively. In addition, the absolute configurations of wailupemycins D (3) and E (4) are also resolved in this paper for the first time.
Boolean Models of Biological Processes Explain Cascade-Like Behavior
Authors: Chen Hao , Wang Guanyu , Simha Rahul , Du Chenghang , Zeng Chen
Published: January 2016

Biological networks play a key role in determining biological function and therefore, an understanding of their structure and dynamics is of central interest in systems biology. In Boolean models of such networks, the status of each molecule is either “on” or “off” and along with the molecules interact with each other, their individual status changes from “on” to “off” or vice-versa and the system of molecules in the network collectively go through a sequence of changes in state. This sequence of changes is termed a biological process. In this paper, we examine the common perception that events in biomolecular networks occur sequentially, in a cascade-like manner, and ask whether this is likely to be an inherent property. In further investigations of the budding and fission yeast cell-cycle, we identify two generic dynamical rules. A Boolean system that complies with these rules will automatically have a certain robustness. By considering the biological requirements in robustness and designability, we show that those Boolean dynamical systems, compared to an arbitrary dynamical system, statistically present the characteristics of cascadeness and sequentiality, as observed in the budding and fission yeast cell- cycle. These results suggest that cascade-like behavior might be an intrinsic property of biological processes.
Donor-derived exosomes induce specific regulatory T cells to suppress immune inflammation in the allograft heart
Authors: Song Jiangping , Huang Jie , Chen Xiao , Teng Xiao , Song Zhizhao , Xing Yong , Wang Mangyuan , Chen Kai , Wang Zheng , Yang Pingchang , Hu Shengshou
Published: January 2016

To inhibit the immune inflammation in the allografts can be beneficial to organ transplantation. This study aims to induce the donor antigen specific regulatory T cells (Treg cell) inhibit the immune inflammation in the allograft heart. In this study, peripheral exosomes were purified from the mouse serum. A heart transplantation mouse model was developed. The immune inflammation of the allograft heart was assessed by histology and flow cytometry. The results showed that the donor antigen-specific T helper (Th)2 pattern inflammation was observed in the allograft hearts; the inflammation was inhibited by immunizing the recipient mice with the donor-derived exosomes. Purified peripheral exosomes contained integrin MMP1a; the latter induced CD4+ T cells to express Fork head protein-3 and transforming growth factor (TGF)-β via inhibiting the Th2 transcription factor, GATA binding protein 3, in CD4+ T cells. Administration with the donor-derived exosomes significantly prolonged the allograft heart survival. We conclude that the donor-derived peripheral exosomes have the capacity to inhibit the immune inflammation in the allograft heart via inducing specific Treg cells, implicating that administration with the donor-derived exosomes may be beneficial to cardiac transplantation.
Conformational Dynamics, Ligand Binding and Effects of Mutations in NirE an S-Adenosyl-L-Methionine Dependent Methyltransferase
Authors: Singh Warispreet , Karabencheva-Christova Tatyana G. , Black Gary W. , Ainsley Jon , Dover Lynn , Christov Christo Z.
Published: January 2016

Heme d1, a vital tetrapyrrol involved in the denitrification processes is synthesized from its precursor molecule precorrin-2 in a chemical reaction catalysed by an S-adenosyl-L-methionine (SAM) dependent Methyltransferase (NirE). The NirE enzyme catalyses the transfer of a methyl group from the SAM to uroporphyrinogen III and serves as a novel potential drug target for the pharmaceutical industry. An important insight into the structure-activity relationships of NirE has been revealed by elucidating its crystal structure, but there is still no understanding about how conformational flexibility influences structure, cofactor and substrate binding by the enzyme as well as the structural effects of mutations of residues involved in binding and catalysis. In order to provide this missing but very important information we performed a comprehensive atomistic molecular dynamics study which revealed that i) the binding of the substrate contributes to the stabilization of the structure of the full complex; ii) conformational changes influence the orientation of the pyrrole rings in the substrate, iii) more open conformation of enzyme active site to accommodate the substrate as an outcome of conformational motions; and iv) the mutations of binding and active site residues lead to sensitive structural changes which influence binding and catalysis.
Characterization of Actin Filament Dynamics during Mitosis in Wheat Protoplasts under UV-B Radiation
Authors: Chen Huize , Han Rong
Published: January 2016

Enhanced ultraviolet-B (UV-B) radiation is caused by the thinning ozone and affects photosynthesis and crop yield. Recently, UV-B radiation has been considered as an environmental signal that regulates plant growth. Elucidating the downstream effectors in UV-B-triggered pathways is of particular interest. Previous studies have shown that actin filaments (AFs) play many roles during cell physiological processes. However, the underlying response of AFs to UV-B radiation remains unclear. In this study, wheat protoplasts were isolated from 7-d-old leaves. The dynamics of AFs during mitosis were observed under different treatments. The protoplasts were treated with UV-B radiation, cytochalasin B (CB) and jasplakinolide (JAS). Ph-FITC labelling results revealed typical actin filament structures in the control group; AFs were rearranged under UV-B radiation. AFs polymerized into bundles during interphase, the preprophase band (PPB) structure was destroyed during prophase and the AFs gathered into plaques during metaphase in response to UV-B radiation. During anaphase and telophase, the distribution of AFs was dispersed. Pharmacologic experiments revealed that CB induced apoptosis and JAS induced nuclear division without cytokinesis in wheat protoplasts. These results indicated that AFs respond to UV-B radiation during mitosis, supplying evidence of UV-B signal transduction in plants.