bluuebunny/crossref_metadata_2025 huggingface dataset:
Complex-valued forecasting of the global solar irradiation
Authors: Saoud L. Saad , Rahmoune F. , Tourtchine V. , Baddari K.
Published: August 2013

In this paper, a forecasting of the global solar irradiation in the complex-valued domain is proposed. A method to transform the meteorological data into complex values is developed and the Complex Valued Neural Network (CVNN) is used to model and forecast the daily and the hourly solar irradiation. The measured data of Tamanrasset city, Algeria (altitude: 1362 m; latitude: 22°48 N; longitude: 05°26 E) is used to validate the developed model. In the hourly solar irradiation case, the 24 h ahead will be forecasted using the combination of the past daily meteorological dataset. Several models are presented to test the feasibility and the performance of the CVNN for forecasting either daily or hourly solar irradiation for both multi input single output and multi input multi output strategies. Results obtained throughout this paper show that the CVNN technique is suitable for modeling and forecasting daily and hourly solar irradiation.
Probing bias stress effect and contact resistance in bilayer ambipolar organic field-effect transistors
Authors: Yan Yan , Sun Qi-Jun , Gao Xu , Deng Ping , Zhang Qing , Wang Sui-Dong
Published: August 2013

The bilayer ambipolar organic field-effect transistors (OFETs) based on 1,8-naphthoylene(trifluoromethylbenzimidazole)-4,5-dicarboxylic acid imide (NTFBII)/pentacene heterojunction have been probed. The origin of the bias stress instability in the top n-channel is attributed to the electron trapping at the NTFBII/pentacene interface, whereas the bias stress effect in the bottom p-channel is associated mainly with the pentacene/dielectric interface. The contact resistances for electron and hole injection are strongly dependent on the local conductivity of the NTFBII and pentacene layers, respectively. The Cu penetration into NTFBII to form direct contact to pentacene is proposed to be the hole injection mechanism in the bilayer ambipolar OFETs.
Ultra-fast excitation dynamics in low bandgap polymer solar cell
Authors: Wang Ying-hui , Zou Lu , Kang Zhi-hui , Qian Cheng , Ma Yu-guang , Zhang Han-zhuang
Published: August 2013

The photovoltaic performance and the photo-physical behaviors based on Poly{2,7′-9,9-dioctylfluorene-alt-5-diethylhexyl-3,6-bis(5-bromothiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4-dione}:PC61BM heterojunction have been studied in detail. The photocurrent and voltage of devices obviously improve after increasing the amount of PC61BM in heterojunction. The transient absorption data exhibit that the dissociation processes of excitons is fast, but that of the charge transfer (CT) state is complicate and owns two paths according to the energy of CT state. In the first situation, the free charge may be directly dissociated from the high energy CT states and its generation rate is too fast to be observed in our detection window. In the low energy CT states, the dissociation process slows down, which is estimated to be 20.8 ps at room temperature. The exciton dissociation in the blend film is so efficient that it could directly take place before exciton-exiton annihilation process at high excitation intensity.
Ultrafast charge-carrier and phonon dynamics in GaP
Authors: Collier C. M. , Born B. , Jin X. , Holzman J. F.
Published: August 2013

The ultrafast energy relaxation of GaP is analyzed through charge-carrier and phonon dynamics. Early timescales show hot electron intervalley scattering from the Γ valley into the X sidevalley, with 700 and 4000 fs time constants for scattering to and from the X7 valley. Later timescales show carrier-phonon interactions in the X6 valley with hot phonon and screening effects. Fluence-dependent relaxation is observed over 30 to 52 ps for 2.3 to 72 μJ/cm2 fluences. The prolonged relaxation of GaP is due to impeded (hot) phonon decay and screening at low and high fluences, respectively.
Large area patterned magnetic films by depositing cobalt layers on nano-wrinkled polydimethylsiloxane templates
Authors: Briones J. , Toro P. , Encinas A. , Caballero L. , Denardin J. C. , Melo F. , Cerda E. , Robert S. , Lacour D. , Montaigne F.
Published: August 2013

We report on a method to fabricate laterally modulated Co films using the artificially induced nano-wrinkled surface of a polydimethylsiloxane polymeric film as template. Large area patterning of self-organized parallel wrinkles is formed displaying a submicrometer wavelength. The subsequent deposition of a Co layer on this wavy surface yields a uniaxial magnetic anisotropy imposed by the wrinkles' morphology. Measurement of the remanent magnetization and coercive field as a function of the field angle confirms the uniaxial nature of the anisotropy and reveals a reversal mechanism more complex than pure coherent rotation. The magnetostatic origin of the anisotropy is analyzed.
Hydrodynamic behaviour of micro/nanoscale Poiseuille flow under thermal creep condition
Authors: Akhlaghi Hassan , Balaj Mojtaba , Roohi Ehsan
Published: August 2013

Current work investigates the effect of thermal creep on the behavior of rarefied gas flow through micro/nanochannels using the direct simulation Monte Carlo method. Thermal creep effects are studied on velocity profiles, streamwise velocity and pressure, and thermal mass flow rate. The strength of thermal creep is examined at different Knudsen number, channel pressure ratio, and bulk temperature. The thermal mass flow rate variation is investigated over a wide range of flow rarefaction from the slip to free molecular regime.
Experimental identification of the out-of-plane phonon mode of a few layered graphene from individual Au nanoparticle-Au film junctions
Authors: Park Won-Hwa , Jung Myunghee , Moon Jin-San , Hwan Noh Seok , Hyeong Kim Tae , Ho Joo Min , Ho Park Kyu
Published: August 2013

We can experimentally identify the layer-layer breathing mode and the other out-of-plane transverse acoustic phonon modes of a few layered graphene via employing z-polarized incident field formed at Au nanoparticle-Au film junctions. The observed out-of-plane mode phonon at ∼150 cm−1 and other transverse acoustic phonon type defect modes from 300 cm−1 to 700 cm−1 can be readily explored. Not only for the normally used optical method using focused plane wave but also direct applying the z-directional electromagnetic field on graphene will be expected for more detailed out-of-plane phonon characterization of graphene.
Anisotropic propagation and upper frequency limitation of terahertz waves in graphene
Authors: Liu XiaoYi , Wang FengChao , Wu HengAn
Published: August 2013

Transverse wave propagation in single-layer graphene sheet (SLGS) is studied via molecular dynamics simulation, continuum, and non-continuum analysis. We found that the propagation of transverse waves with frequency over 3 THz is remarkably chirality-dependent. Furthermore, the wave propagation in zigzag direction remains undistorted only when the frequency is below 16 THz, while this threshold is 10 THz in the armchair direction. The minimum permissible wavelength is proposed to explain the frequency limitation due to non-continuity. Our findings lead to an improved fundamental understanding on the vibration of graphene-based nanodevices and have potential applications in design and fabrication of nanoelectromechanical systems.
Characterization of polishing induced defects and hydrofluoric acid passivation effect in ZnO
Authors: Zhang Zhichun , Quemener V. , Lin C.-H. , Svensson B. G. , Brillson L. J.
Published: August 2013

We used depth-resolved cathodoluminescence spectroscopy and transient photovoltage spectroscopy (T-SPS) measurements to study the spatial distributions and densities of native point defects in bulk ZnO samples subjected to mechanical polishing and how the defects change with hydrofluoric acid (HF) etching. Mechanical polishing produces Zn vacancy-related defects that deplete free carriers at depths extending to 300–500 nm, while HF etching removes/passivates these defects as well as bulk oxygen vacancy-related defects, restoring the charge carriers below the etched surface. T-SPS defect density changes with polishing/etching correlate closely with deep level transient spectroscopy densities, demonstrating the applicability of T-SPS as a non-contact quantitative defect density measurement technique.
Concise Synthesis of Enantiomerically Pure (1'S,2'R)- and (1'R,2'S)-2S-Amino-3-(2'-aminomethyl-cyclopropyl)propionic Acid: Two E-Diastereoisomers of 4,5-Methano-L-lysine
Authors: Altamore Timothy M. , Nguyen Oanh T. K. , Churches Quentin I. , Cavanagh Kate , Nguyen Xuan T. T. , Duggan Sandhya A. M. , Krippner Guy Y. , Duggan Peter J.
Published: August 2013

A concise synthesis of both E-isomers of 2S-amino-3-(2′-aminomethyl-cyclopropyl)propionic acid, new methano-l-lysines, is described. The synthetic route includes nine steps from l-methionine, with a key step involving the cyclopropanation of an intermediate E-allylic alcohol. The resultant hydroxymethylcyclopropanes were readily separated and converted into the title α-amino acids. The stereochemistry around the cyclopropane rings was deduced by conducting the cyclopropanation in the presence of N,N,N′,N′-tetramethyl-d-tartaric acid diamide butylboronate, a chiral controller which is known to favour the production of S-hydroxymethyl cyclopropanes from allylic alcohols.
The career and contribution to Australian and international agricultural science of Clive McDonald Francis: an introduction
Authors: Ewing M. A. , Chatel D. L. , Poole M. L. , Collins W. J.
Published: August 2013

Dr Clive Francis is amongst a small group of scientists whose efforts have changed the face of Australian agriculture. This special issue of Crop & Pasture Science highlights his broadranging impact delivered through the pasture cultivars he bred, the knowledge that he generated and the influence that he had on peers and policy makers. His cultivars of subterranean clover are still grown on many millions of hectares across southern Australia and his efforts were pivotal in generating momentum for creative research on a wide array of crop and pasture legumes, particularly the collection, evaluation and preservation of genetic resources for use in current and future breeding initiatives.
Genetic improvement of subterranean clover (Trifolium subterraneum L.). 1. Germplasm, traits and future prospects
Authors: Nichols P. G. H. , Foster K. J. , Piano E. , Pecetti L. , Kaur P. , Ghamkhar K. , Collins W. J.
Published: August 2013

Subterranean clover (Trifolium subterraneum L.) is the most widely sown annual pasture legume species in southern Australia, valued in the livestock and grains industries as a source of high-quality forage and for its ability to fix atmospheric nitrogen. From its initial accidental introduction into Australia in the 19th Century and subsequent commercialisation in the early 1900s, 45 cultivars have been registered in Australia. These consist of 32 cultivars of ssp. subterraneum, eight of ssp. yanninicum, and five of ssp. brachycalycinum and range in flowering time from 77 to 163 days from sowing, enabling the species to be grown in a diversity of rainfall environments, soil types, and farming systems. Eleven of these cultivars are introductions from the Mediterranean region, 15 are naturalised strains collected in Australia, 18 are the products of crossbreeding, and one is derived from mutagenesis. Cultivars developed in Italy have been commercialised for the local market, whereas other cultivars developed in Spain, Portugal, and France have not had commercial seed production. Important traits exploited include: (i) selection for low levels of the oestrogenic isoflavone formononetin, which causes reduced ewe fertility; (ii) increased levels of dormancy imposed by seed-coat impermeability (hard seeds) for cultivars aimed at crop rotations or unreliable rainfall environments; (iii) strong burr-burial ability to maximise seed production; (iv) resistance to important disease pathogens for cultivars aimed at medium- and high-rainfall environments, particularly to Kabatiella caulivora and root rot pathogens; (v) resistance to pests, particularly redlegged earth mites; and (vi) selection for unique leaf markings and other morphological traits (where possible) to aid cultivar identification. Cultivar development has been aided by a large genetic resource of ~10 000 accessions, assembled from its centre of origin in the Mediterranean Basin, West Asia, and the Atlantic coast of Western Europe, in addition to naturalised strains collected in Australia. The development of a core collection of 97 accessions, representing almost 80% of the genetic diversity of the species, and a genetic map, provides a platform for development of future cultivars with new traits to benefit the livestock and grains industries. New traits being examined include increased phosphorous-use efficiency and reduced methane emissions from grazing ruminant livestock. Economic analyses indicate that future trait development should focus on traits contributing to increased persistence and autumn–winter productivity, while other potential traits include increased nutritive value (particularly of senesced material), increased N2 fixation ability, and tolerance to cheap herbicides. Beneficial compounds for animal and human health may also be present within the species for exploitation.
Communicating science in politicized environments
Authors: Lupia Arthur
Published: August 2013

Many members of the scientific community attempt to convey information to policymakers and the public. Much of this information is ignored or misinterpreted. This article describes why these outcomes occur and how science communicators can achieve better outcomes. The article focuses on two challenges associated with communicating scientific information to such audiences. One challenge is that people have less capacity to pay attention to scientific presentations than many communicators anticipate. A second challenge is that people in politicized environments often make different choices about whom to believe than do people in other settings. Together, these challenges cause policymakers and the public to be less responsive to scientific information than many communicators desire. Research on attention and source credibility can help science communicators better adapt to these challenges. Attention research clarifies when, and to what type of stimuli, people do (and do not) pay attention. Source credibility research clarifies the conditions under which an audience will believe scientists’ descriptions of phenomena rather than the descriptions of less-valid sources. Such research can help communicators stay true to their science while making their findings more memorable and more believable to more audiences.
Unexpected variations in the triple oxygen isotope composition of stratospheric carbon dioxide
Authors: Wiegel Aaron A. , Cole Amanda S. , Hoag Katherine J. , Atlas Elliot L. , Schauffler Sue M. , Boering Kristie A.
Published: August 2013

We report observations of stratospheric CO
2
that reveal surprisingly large anomalous enrichments in
17
O that vary systematically with latitude, altitude, and season. The triple isotope slopes reached 1.95 ± 0.05(1σ) in the middle stratosphere and 2.22 ± 0.07 in the Arctic vortex versus 1.71 ± 0.03 from previous observations and a remarkable factor of 4 larger than the mass-dependent value of 0.52. Kinetics modeling of laboratory measurements of photochemical ozone–CO
2
isotope exchange demonstrates that non–mass-dependent isotope effects in ozone formation alone quantitatively account for the
17
O anomaly in CO
2
in the laboratory, resolving long-standing discrepancies between models and laboratory measurements. Model sensitivities to hypothetical mass-dependent isotope effects in reactions involving O
3
, O(
1
D), or CO
2
and to an empirically derived temperature dependence of the anomalous kinetic isotope effects in ozone formation then provide a conceptual framework for understanding the differences in the isotopic composition and the triple isotope slopes between the laboratory and the stratosphere and between different regions of the stratosphere. This understanding in turn provides a firmer foundation for the diverse biogeochemical and paleoclimate applications of
17
O anomalies in tropospheric CO
2
, O
2
, mineral sulfates, and fossil bones and teeth, which all derive from stratospheric CO
2
.
Immunomodulatory effect of a decellularized skeletal muscle scaffold in a discordant xenotransplantation model
Authors: Fishman Jonathan M. , Lowdell Mark W. , Urbani Luca , Ansari Tahera , Burns Alan J. , Turmaine Mark , North Janet , Sibbons Paul , Seifalian Alexander M. , Wood Kathryn J. , Birchall Martin A. , De Coppi Paolo
Published: August 2013

Decellularized (acellular) scaffolds, composed of natural extracellular matrix, form the basis of an emerging generation of tissue-engineered organ and tissue replacements capable of transforming healthcare. Prime requirements for allogeneic, or xenogeneic, decellularized scaffolds are biocompatibility and absence of rejection. The humoral immune response to decellularized scaffolds has been well documented, but there is a lack of data on the cell-mediated immune response toward them in vitro and in vivo. Skeletal muscle scaffolds were decellularized, characterized in vitro, and xenotransplanted. The cellular immune response toward scaffolds was evaluated by immunohistochemistry and quantified stereologically. T-cell proliferation and cytokines, as assessed by flow cytometry using carboxy-fluorescein diacetate succinimidyl ester dye and cytometric bead array, formed an in vitro surrogate marker and correlate of the in vivo host immune response toward the scaffold. Decellularized scaffolds were free of major histocompatibility complex class I and II antigens and were found to exert anti-inflammatory and immunosuppressive effects, as evidenced by delayed biodegradation time in vivo; reduced sensitized T-cell proliferative activity in vitro; reduced IL-2, IFN-γ, and raised IL-10 levels in cell-culture supernatants; polarization of the macrophage response in vivo toward an M2 phenotype; and improved survival of donor-derived xenogeneic cells at 2 and 4 wk in vivo. Decellularized scaffolds polarize host responses away from a classical TH1-proinflammatory profile and appear to down-regulate T-cell xeno responses and TH1 effector function by inducing a state of peripheral T-cell hyporesponsiveness. These results have substantial implications for the future clinical application of tissue-engineered therapies.
Tuning a riboswitch response through structural extension of a pseudoknot
Authors: Soulière Marie F. , Altman Roger B. , Schwarz Veronika , Haller Andrea , Blanchard Scott C. , Micura Ronald
Published: August 2013

Significance

The three-dimensional fold and inherent structural dynamics of RNA are critical determinants of function. Although the hierarchical folding of RNA secondary structure followed by tertiary structure formation is well established, insights into how secondary structure units impact tertiary structure formation and dynamics remain elusive. Using single-molecule FRET imaging of the preQ
1
class II bacterial riboswitch, we reveal that RNA employs stem–loop insertions into classical pseudoknots as a tool to tune ligand response and hence the outcome of natural gene-regulatory elements.
Transient, afferent input-dependent, postnatal niche for neural progenitor cells in the cochlear nucleus
Authors: Volkenstein Stefan , Oshima Kazuo , Sinkkonen Saku T. , Corrales C. Eduardo , Most Sam P. , Chai Renjie , Jan Taha A. , van Amerongen Renée , Cheng Alan G. , Heller Stefan
Published: August 2013

Significance

The cochlear nucleus is the first central relay station for auditory signals from the cochlea. Like many other central relays for sensory systems, the cochlear nucleus features a period in newborn animals during which neuron survival and the number of synaptic contacts depends on afferent innervation from the periphery. This study extends this concept of postnatal plasticity toward neurogenesis. We identified neural progenitor cells in the cochlear nucleus whose proliferative capacity is controlled by interplay of several signaling pathways. When the cochlea was removed, the proliferating cell population diminished, suggesting that signals from the periphery are required to maintain this plasticity.
Live-cell imaging of Marburg virus-infected cells uncovers actin-dependent transport of nucleocapsids over long distances
Authors: Schudt Gordian , Kolesnikova Larissa , Dolnik Olga , Sodeik Beate , Becker Stephan
Published: August 2013

Transport of large viral nucleocapsids from replication centers to assembly sites requires contributions from the host cytoskeleton via cellular adaptor and motor proteins. For the Marburg and Ebola viruses, related viruses that cause severe hemorrhagic fevers, the mechanism of nucleocapsid transport remains poorly understood. Here we developed and used live-cell imaging of fluorescently labeled viral and host proteins to characterize the dynamics and molecular requirements of nucleocapsid transport in Marburg virus-infected cells under biosafety level 4 conditions. The study showed a complex actin-based transport of nucleocapsids over long distances from the viral replication centers to the budding sites. Only after the nucleocapsids had associated with the matrix viral protein VP40 at the plasma membrane were they recruited into filopodia and cotransported with host motor myosin 10 toward the budding sites at the tip or side of the long cellular protrusions. Three different transport modes and velocities were identified: (
i
) Along actin filaments in the cytosol, nucleocapsids were transported at ∼200 nm/s; (
ii
) nucleocapsids migrated from one actin filament to another at ∼400 nm/s; and (
iii
) VP40-associated nucleocapsids moved inside filopodia at 100 nm/s. Unique insights into the spatiotemporal dynamics of nucleocapsids and their interaction with the cytoskeleton and motor proteins can lead to novel classes of antivirals that interfere with the trafficking and subsequent release of the Marburg virus from infected cells.
Availability of public goods shapes the evolution of competing metabolic strategies
Authors: Bachmann Herwig , Fischlechner Martin , Rabbers Iraes , Barfa Nakul , Branco dos Santos Filipe , Molenaar Douwe , Teusink Bas
Published: August 2013

Tradeoffs provide a rationale for the outcome of natural selection. A prominent example is the negative correlation between the growth rate and the biomass yield in unicellular organisms. This tradeoff leads to a dilemma, where the optimization of growth rate is advantageous for an individual, whereas the optimization of the biomass yield would be advantageous for a population. High-rate strategies are observed in a broad variety of organisms such as
Escherichia coli
, yeast, and cancer cells. Growth in suspension cultures favors fast-growing organisms, whereas spatial structure is of importance for the evolution of high-yield strategies. Despite this realization, experimental methods to directly select for increased yield are lacking. We here show that the serial propagation of a microbial population in a water-in-oil emulsion allows selection of strains with increased biomass yield. The propagation in emulsion creates a spatially structured environment where the growth-limiting substrate is privatized for populations founded by individual cells. Experimental evolution of several isogenic
Lactococcus lactis
strains demonstrated the existence of a tradeoff between growth rate and biomass yield as an apparent Pareto front. The underlying mutations altered glucose transport and led to major shifts between homofermentative and heterofermentative metabolism, accounting for the changes in metabolic efficiency. The results demonstrated the impact of privatizing a public good on the evolutionary outcome between competing metabolic strategies. The presented approach allows the investigation of fundamental questions in biology such as the evolution of cooperation, cell–cell interactions, and the relationships between environmental and metabolic constraints.
Nonclassical MHC class I-dependent invariant T cells are evolutionarily conserved and prominent from early development in amphibians
Authors: Edholm Eva-Stina , Albertorio Saez Liz-Marie , Gill Ann L. , Gill Steven R. , Grayfer Leon , Haynes Nikesha , Myers Jason R. , Robert Jacques
Published: August 2013

Human and murine MHC nonclassical class Ib-restricted invariant T (iT) cell subsets, such as invariant natural killer T cells (iNKT) and mucosal-associated invariant T cells, have specialized functions early in immune responses, especially in modulating subsequent adaptive immune responses. Here, we characterize a prominent iT population in the amphibianXenopus laevisand show the requirement of the class Ib molecule,Xenopusnonclassical gene 10, in its differentiation and function. UsingXenopusnonclassical gene 10 tetramers and RNAi loss of function by transgenesis, we identified a large class Ib-dependent CD8−/CD4−iT subset in unmanipulated frogs and tadpoles. This population is critical for antiviral immunity during early larval stages when classical MHC class Ia function is suboptimal. Furthermore, in young tadpoles with low class Ia expression, deep sequencing revealed additional preponderant invariant T cell receptor (TCR)α rearrangements, implying other iT cell subsets and a predominant selection process mediated by other class Ib molecules. The restriction and requirement of class Ib molecules for development and antiviral immunity of a mammalian iNKT or mucosal-associated invariant T cell counterpart in the amphibianXenopusshow the importance of iT cells in the emergence and evolution of the adaptive immune system.
Growth hormone is a cellular senescence target in pituitary and nonpituitary cells
Authors: Chesnokova Vera , Zhou Cuiqi , Ben-Shlomo Anat , Zonis Svetlana , Tani Yuji , Ren Song-Guang , Melmed Shlomo
Published: August 2013

Significance

Growth hormone (GH) is secreted to the circulation by anterior pituitary somatotroph cells and is also expressed locally in peripheral tissues. This study identifies GH as a target for p53-induced senescence in both pituitary and nonpituitary cells. We show marked induction of intracellular GH expression and secretion in response to activation of the p53 DNA damage pathway. GH is shown to be a direct transcriptional target for p53, and up-regulated GH protects pituitary tumor cells from apoptosis. The results demonstrate a novel mechanism determining the pathophysiology of GH-secreting pituitary tumors and elucidate a basis for the invariably benign nature of these adenomas. Our findings show that induced GH can serve as a readily measurable marker for p53-induced senescence.
Isothermal amplification method for next-generation sequencing
Authors: Ma Zhaochun , Lee Raymond W. , Li Bin , Kenney Paul , Wang Yufang , Erikson Jonathan , Goyal Swati , Lao Kaiqin
Published: August 2013

Significance

We have developed a cost-effective in situ isothermal amplification method for next-generation sequencing (NGS) that can generate billions of monoclonal colonies in less than 30 minutes. This method can be used on NGS platforms to make the $1,000 genome possible and simplify the workflow for clinical genomic applications.
An alternative polyadenylation mechanism coopted to the
Arabidopsis RPP7
gene through intronic retrotransposon domestication
Authors: Tsuchiya Tokuji , Eulgem Thomas
Published: August 2013

Significance

We show the histone mark H3K9me2, which is known to mediate transposon silencing, to determine the choice between alternative polyadenylation sites within the
Arabidopsis thaliana
disease resistance gene
RPP7
. High H3K9me2 levels recruited to the first
RPP7
intron by the
COPIA-R7
retrotransposon suppress use of a promoter-proximal polyadenylation site. Modulating H3K9me2 levels at this site shifts the balance between full-length and incomplete RPP7 transcripts. By recruiting H3K9me2-dependent polyadenylation control to
RPP7
, the
COPIA-R7
insertion provided a new switch to fine-tune
RPP7
expression. Selective advantages resulting from this mechanism likely contributed to the domestication of
COPIA-R7
at
RPP7
.
Core foundations of abstract geometry
Authors: Dillon Moira R. , Huang Yi , Spelke Elizabeth S.
Published: August 2013

Human adults from diverse cultures share intuitions about the points, lines, and figures of Euclidean geometry. Do children develop these intuitions by drawing on phylogenetically ancient and developmentally precocious geometric representations that guide their navigation and their analysis of object shape? In what way might these early-arising representations support later-developing Euclidean intuitions? To approach these questions, we investigated the relations among young children’s use of geometry in tasks assessing: navigation; visual form analysis; and the interpretation of symbolic, purely geometric maps. Children’s navigation depended on the distance and directional relations of the surface layout and predicted their use of a symbolic map with targets designated by surface distances. In contrast, children’s analysis of visual forms depended on the size-invariant shape relations of objects and predicted their use of the same map but with targets designated by corner angles. Even though the two map tasks used identical instructions and map displays, children’s performance on these tasks showed no evidence of integrated representations of distance and angle. Instead, young children flexibly recruited geometric representations of either navigable layouts or objects to interpret the same spatial symbols. These findings reveal a link between the early-arising geometric representations that humans share with diverse animals and the flexible geometric intuitions that give rise to human knowledge at its highest reaches. Although young children do not appear to integrate core geometric representations, children’s use of the abstract geometry in spatial symbols such as maps may provide the earliest clues to the later construction of Euclidean geometry.
Mortality and Growth of Crayfish Internally Tagged with PIT Tags
Authors: Westhoff Jacob T. , Sievert Nicholas A.
Published: August 2013

Advances in PIT technology have resulted in its increased use to answer ecological questions related to small-bodied organisms. Crayfish are increasingly the subject of such study, and information is needed to guide researchers in determining appropriate uses of the technology for various applications. We internally tagged woodland crayfish Orconectes hylas with either 8.5 mm or 12.5 mm PIT tags and evaluated mortality and growth in the laboratory over 55 d. A logistic model showed that the probability of mortality drops below 20% for crayfish tagged with 8.5-mm or 12.5-mm tags when carapace length (CL) was greater than 23 mm and 26 mm, respectively. There was a positive relation between CL and growth, a difference between growth in males and females, and no statistical difference in growth among treatment types (8.5-mm tag, 12.5-mm tag, controls). Internal implantation of PIT tags into appropriately sized crayfish represents a viable tagging option for many crayfish research applications.

Received February 19, 2013; accepted June 11, 2013
Profile of Addicted Patients who Reenter Treatment Programs
Authors: López-Goñi José J. , Fernández-Montalvo Javier , Cacho Raúl , Arteaga Alfonso
Published: August 2013

Background

Clinical experience shows that some patients who suffer from drug addiction are readmitted to treatment programs multiple times because of relapses that occur after they leave these programs. Patients who reenter treatment programs repeatedly may do so because they have problems or difficulties that were not addressed or that were not satisfactorily solved during previous treatment periods. This study explored the differential profile of addicted patients who reenter treatment programs.

Methods

A sample of 252 addicted patients (203 male and 49 female) who sought outpatient treatment was assessed. Data regarding sociodemographic factors, drug consumption factors (assessed using the EuropASI), psychopathological factors (assessed using the Symptom Checklist-90—Revised [SCL-90-R]), and personality variables (assessed using the Millon Clinical Multiaxial Inventory II [MCMI-II]) were collected.

Results

A 65.9% ( n = 166) of drug-addicted patients were readmitted into treatment programs. All of the variables for which data were collected were compared between these treatment repeaters and patients who were admitted for the first time. Significant differences between the 2 groups of patients were found for some of the variables that we examined. Treatment repeaters were generally older and had a poorer employment situation than first-time admits. Treatment repeaters were also more likely to report polyconsumption and to have sought treatment for alcohol abuse. Moreover, some of the scores for several EuropASI, SCL-90-R, and MCMI-II variables were statistically significantly different from those of the first-time admits.

Conclusions

According to these results, patients who reenter treatment programs often present with more severe addiction problems. All of these data suggest that treatment programs should incorporate a detailed analysis regarding the existence and nature of prior treatments into the baseline protocols and they should offer follow-up services to patients who have completed their treatments. The implications of these results for further research and clinical practice are discussed.
You Better Stop! Binding “Stop” Tags to Irrelevant Stimulus Features
Authors: Giesen Carina , Rothermund Klaus
Published: August 2013

We investigated whether the basic process of integrating stimuli (and their features) with simultaneously executed responses transfers to situations in which one does not respond to a stimulus. In three experiments, a stop-signal task was combined with a sequential priming paradigm to test whether irrelevant stimulus features become associated with a “stop” tag. Stopping a simple response during the prime trial delayed responding and facilitated stopping in the probe if the same irrelevant stimulus feature was repeated in the probe. These repetition priming effects were independent of the relation between the to-be-executed (or to-be-stopped) responses in the prime and probe, indicating that “stop” tags are global (“stop all responses!”) rather than being response-related (e.g., “stop left response!”).
Problematics of political authority within Islam
Authors: Mazouz Muhammad
Published: August 2013

This paper sets out to disentangle what is discernible from the historical record and the evidence from legendary accounts of the spread of Islam by conquest. It argues that rather than by the sword, Islam came to Spain through the development and succession of ideas. The paper further deconstructs the theory of Islamic governance, attributing forms of rule not to Islamic teachings but to prevailing power structures and struggles. It is contended that what is known of specific incidents reaches us through the narration of the incident, rather than by its physical existence. If a serious event takes place, it reaches us through a serious Hadith (like the Prophet’s Hadith), but if the incident is not very significant or did not take place at all – but an authority wants it to have happened – it reaches us as a legend. The legend starts where history ends, and takes its place to complete the story’s events. History depicts and legend narrates.
hGAAP promotes cell adhesion and migration via the stimulation of store-operated Ca2+ entry and calpain 2
Authors: Saraiva Nuno , Prole David L. , Carrara Guia , Johnson Benjamin F. , Taylor Colin W. , Parsons Maddy , Smith Geoffrey L.
Published: August 2013

Golgi antiapoptotic proteins (GAAPs) are highly conserved Golgi membrane proteins that inhibit apoptosis and promote Ca2+ release from intracellular stores. Given the role of Ca2+ in controlling cell adhesion and motility, we hypothesized that human GAAP (hGAAP) might influence these events. In this paper, we present evidence that hGAAP increased cell adhesion, spreading, and migration in a manner that depended on the C-terminal domain of hGAAP. We show that hGAAP increased store-operated Ca2+ entry and thereby the activity of calpain at newly forming protrusions. These hGAAP-dependent effects regulated focal adhesion dynamics and cell migration. Indeed, inhibition or knockdown of calpain 2 abrogated the effects of hGAAP on cell spreading and migration. Our data reveal that hGAAP is a novel regulator of focal adhesion dynamics, cell adhesion, and migration by controlling localized Ca2+-dependent activation of calpain.
Atg18 phosphoregulation controls organellar dynamics by modulating its phosphoinositide-binding activity
Authors: Tamura Naoki , Oku Masahide , Ito Moemi , Noda Nobuo N. , Inagaki Fuyuhiko , Sakai Yasuyoshi
Published: August 2013

The PROPPIN family member Atg18 is a phosphoinositide-binding protein that is composed of a seven β-propeller motif and is part of the conserved autophagy machinery. Here, we report that the Atg18 phosphorylation in the loops in the propellar structure of blade 6 and blade 7 decreases its binding affinity to phosphatidylinositol 3,5-bisphosphate in the yeast Pichia pastoris. Dephosphorylation of Atg18 was necessary for its association with the vacuolar membrane and caused septation of the vacuole. Upon or after dissociation from the vacuolar membrane, Atg18 was rephosphorylated, and the vacuoles fused and formed a single rounded structure. Vacuolar dynamics were regulated according to osmotic changes, oxidative stresses, and nutrient conditions inducing micropexophagy via modulation of Atg18 phosphorylation. This study reveals how the phosphoinositide-binding activity of the PROPPIN family protein Atg18 is regulated at the membrane association domain and highlights the importance of such phosphoregulation in coordinated intracellular reorganization.
A role for gut-associated lymphoid tissue in shaping the human B cell repertoire
Authors: Vossenkämper Anna , Blair Paul A. , Safinia Niloufar , Fraser Louise D. , Das Lisa , Sanders Theodore J. , Stagg Andrew J. , Sanderson Jeremy D. , Taylor Kirstin , Chang Fuju , Choong Lee M. , D’Cruz David P. , MacDonald Thomas T. , Lombardi Giovanna , Spencer Jo
Published: August 2013

We have tracked the fate of immature human B cells at a critical stage in their development when the mature B cell repertoire is shaped. We show that a major subset of bone marrow emigrant immature human B cells, the transitional 2 (T2) B cells, homes to gut-associated lymphoid tissue (GALT) and that most T2 B cells isolated from human GALT are activated. Activation in GALT is a previously unknown potential fate for immature human B cells. The process of maturation from immature transitional B cell through to mature naive B cell includes the removal of autoreactive cells from the developing repertoire, a process which is known to fail in systemic lupus erythematosus (SLE). We observe that immature B cells in SLE are poorly equipped to access the gut and that gut immune compartments are depleted in SLE. Thus, activation of immature B cells in GALT may function as a checkpoint that protects against autoimmunity. In healthy individuals, this pathway may be involved in generating the vast population of IgA plasma cells and also the enigmatic marginal zone B cell subset that is poorly understood in humans.
Interactions among DIV voltage-sensor movement, fast inactivation, and resurgent Na current induced by the NaVβ4 open-channel blocking peptide
Authors: Lewis Amanda H. , Raman Indira M.
Published: August 2013

Resurgent Na current flows as voltage-gated Na channels recover through open states from block by an endogenous open-channel blocking protein, such as the NaVβ4 subunit. The open-channel blocker and fast-inactivation gate apparently compete directly, as slowing the onset of fast inactivation increases resurgent currents by favoring binding of the blocker. Here, we tested whether open-channel block is also sensitive to deployment of the DIV voltage sensor, which facilitates fast inactivation. We expressed NaV1.4 channels in HEK293t cells and assessed block by a free peptide replicating the cytoplasmic tail of NaVβ4 (the “β4 peptide”). Macroscopic fast inactivation was disrupted by mutations of DIS6 (L443C/A444W; “CW” channels), which reduce fast-inactivation gate binding, and/or by the site-3 toxin ATX-II, which interferes with DIV movement. In wild-type channels, the β4 peptide competed poorly with fast inactivation, but block was enhanced by ATX. With the CW mutation, large peptide-induced resurgent currents were present even without ATX, consistent with increased open-channel block upon depolarization and slower deactivation after blocker unbinding upon repolarization. The addition of ATX greatly increased transient current amplitudes and further enlarged resurgent currents, suggesting that pore access by the blocker is actually decreased by full deployment of the DIV voltage sensor. ATX accelerated recovery from block at hyperpolarized potentials, however, suggesting that the peptide unbinds more readily when DIV voltage-sensor deployment is disrupted. These results are consistent with two open states in Na channels, dependent on the DIV voltage-sensor position, which differ in affinity for the blocking protein.
Q/R site interactions with the M3 helix in GluK2 kainate receptor channels revealed by thermodynamic mutant cycles
Authors: Lopez Melany N. , Wilding Timothy J. , Huettner James E.
Published: August 2013

RNA editing at the Q/R site near the apex of the pore loop of AMPA and kainate receptors controls a diverse array of channel properties, including ion selectivity and unitary conductance and susceptibility to inhibition by polyamines and cis-unsaturated fatty acids, as well as subunit assembly into tetramers and regulation by auxiliary subunits. How these different aspects of channel function are all determined by a single amino acid substitution remains poorly understood; however, several lines of evidence suggest that interaction between the pore helix (M2) and adjacent segments of the transmembrane inner (M3) and outer (M1) helices may be involved. In the present study, we have used double mutant cycle analysis to test for energetic coupling between the Q/R site residue and amino acid side chains along the M3 helix. Our results demonstrate interaction with several M3 locations and particularly strong coupling to substitution for L614 at the level of the central cavity. In this location, replacement with smaller side chains completely and selectively reverses the effect of fatty acids on gating of edited channels, converting strong inhibition of wild-type GluK2(R) to nearly 10-fold potentiation of GluK2(R) L614A.
Antibody-guided photoablation of voltage-gated potassium currents
Authors: Sack Jon T. , Stephanopoulos Nicholas , Austin Daniel C. , Francis Matthew B. , Trimmer James S.
Published: August 2013

A family of 40 mammalian voltage-gated potassium (Kv) channels control membrane excitability in electrically excitable cells. The contribution of individual Kv channel types to electrophysiological signaling has been difficult to assign, as few selective inhibitors exist for individual Kv subunits. Guided by the exquisite selectivity of immune system interactions, we find potential for antibody conjugates as selective Kv inhibitors. Here, functionally benign anti-Kv channel monoclonal antibodies (mAbs) were chemically modified to facilitate photoablation of K currents. Antibodies were conjugated to porphyrin compounds that upon photostimulation inflict localized oxidative damage. Anti-Kv4.2 mAb–porphyrin conjugates facilitated photoablation of Kv4.2 currents. The degree of K current ablation was dependent on photon dose and conjugate concentration. Kv channel photoablation was selective for Kv4.2 over Kv4.3 or Kv2.1, yielding specificity not present in existing neurotoxins or other Kv channel inhibitors. We conclude that antibody–porphyrin conjugates are capable of selective photoablation of Kv currents. These findings demonstrate that subtype-specific mAbs that in themselves do not modulate ion channel function are capable of delivering functional payloads to specific ion channel targets.
On positive cubature rules on the simplex and isometric embeddings
Authors: Sawa Masanori , Xu Yuan
Published: August 2013

Positive cubature rules of degree

4
4

and

5
5

on the

d
d

-dimensional simplex are constructed for a range of dimensions

d
d

and used to construct cubature rules of index

8
8

or degree

9
9

on the unit sphere. The latter ones lead to explicit isometric embedding among the classical Banach spaces. Among other things, our results include several explicit representations of

(

x
1
2

+
⋯
+

x
d
2

)
t

(x_1^2+ \cdots + x_d^2)^t

in terms of linear forms of degree

2
t

2t

with rational coefficients for

t
=
4

t = 4

and

5
5

.
What can plants do for cell biology?
Authors: Bezanilla Magdalena
Published: August 2013

Historically, cell biologists studied organisms that represented a reasonable sampling of life's diversity, whereas recently research has narrowed into a few model systems. As a result, the cells of plants have been relatively neglected. Here I choose three examples to illustrate how plants have been informative and could be even more so. Owing to their ease of imaging and genetic tractability, multicellular plant model systems provide a unique opportunity to address long-standing questions in cell biology.
White Pine Blister Rust Resistance in Limber Pine: Evidence for a Major Gene
Authors: Schoettle A. W. , Sniezko R. A. , Kegley A. , Burns K. S.
Published: August 2013

Limber pine (Pinus flexilis) is being threatened by the lethal disease white pine blister rust caused by the non-native pathogen Cronartium ribicola. The types and frequencies of genetic resistance to the rust will likely determine the potential success of restoration or proactive measures. These first extensive inoculation trials using individual tree seed collections from >100 limber pine trees confirm that genetic segregation of a stem symptom-free trait to blister rust is consistent with inheritance by a single dominant resistance (R) gene, and the resistance allele appears to be distinct from the R allele in western white pine. Following previous conventions, we are naming the R gene for limber pine “Cr4.” The frequency of the Cr4 allele across healthy and recently invaded populations in the Southern Rocky Mountains was unexpectedly high (5.0%, ranging from 0 to 13.9%). Cr4 is in equilibrium, suggesting that it is not a product of a recent mutation and may have other adaptive significance within the species, possibly related to other abiotic or biotic stress factors. The identification of Cr4 in native populations of limber pine early in the invasion progress in this region provides useful information for predicting near-term impacts and structuring long-term management strategies.