bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep submicron parallel scanning probe lithography using two‐degree‐of‐freedom microelectromechanical systems actuators with integrated nanotips
Authors: Mehdizadeh Emad , Pourkamali Siavash
Published: October 2014

A new enabling technology for low‐cost high throughput parallel scanning probe nanolithography is presented. Monolithic integration of microelectromechanical systems (MEMS) actuators with two‐dimensional probe arrays as well as preliminary results in the simultaneous generation of multiple submicron patterns using such structures is reported. Two‐degree‐of‐freedom electrothermal MEMS positioning structures integrated with nanoscale probe‐tips are used to perform parallel scanning probe nanolithography circumventing the main deficiency of tip‐based nanolithography, that is, low throughput. Simultaneous generation of multiple patterns scratched into 800 nm thick photoresist and 200 nm thick gold layers has been successfully demonstrated. Scratch marks as narrow and as long as ∼50 and 27 µm, respectively, have been generated in the X and Y directions using two different microactuator structures carrying 10 and 64 nanotips.
Effect of current density on silicon surface in electrochemical etching
Authors: Burham Norhafizah , Hamzah Azrul Azlan , Majlis Burhanuddin Yeop
Published: October 2014

A simple and reliable fabrication technique for producing nanoporous filters is presented. The nanoporous filter plays an important role in biomedical microelectromechanical systems applications, especially in filtering out waste and solute from inside human blood. Nanosized components in the biological fluid are filtered using silicon membranes that are controlled by nanosized pores. The technique explored was the electrochemical etching (ECE) process of silicon. This approach starts with thinning the bulk silicon until only several micrometres thick using the KOH process and then carry out ECE to produce pores. The yield of the process was a 3 µm thick nanoporous silicon membrane with pore sizes of less than 100 nm. This physical characteristic enables the membrane to filter all the waste and solute particles of less than 100 nm. Owing to this simple and reliable method, the development of nanoporous silicon membrane can be used in nanofiltration applications especially in an artificial kidney.
Die digitale Volumentomografie in der kieferorthopädischen Praxis
Authors: Nelson G.
Published: October 2014

In diesem Beitrag werden die Einsatzmöglichkeiten der Volumentomografie in der kieferorthopädischen Praxis erläutert und auf die diagnostischen Möglichkeiten, die Strahlenbelastung für Patienten und auf Fragen der Haftung wird eingegangen. Des Weiteren wird ein Überblick über wichtige Forschungsergebnisse gegeben, von denen etliche in der Abteilung für Kieferorthopädie der Universität von Kalifornien in San Francisco (UCSF) durchgeführt wurden. Schließlich wird ein systematisches Verfahren zur Beurteilung eines Volumentomogramms vorgestellt.
Kinderanästhesie
Authors: Fischer Thomas
Published: October 2014

Anästhesie als Fachgebiet ist für die schmerzfreie operative Versorgung nötig und nahezu symbiotisch mit der Tätigkeit des Chirurgen verbunden. Anästhesisten müssen neben dem eigentlichen operativen Eingriff das Alter des Patienten und seine Begleiterkrankungen sowie zu erwartende Schwierigkeiten während der Operation in ihre Tätigkeit integrieren. Die anästhesiologische Versorgung von Kindern, speziell von Neugeborenen mit angeborenen Fehlbildungen, ist ein besonderer Bereich der Anästhesie – verbunden mit einem hohen Behandlungsrisiko für den Anästhesisten.
Accurate potential drop sheet resistance measurements of laser-doped areas in semiconductors
Authors: Heinrich Martin , Kluska Sven , Binder Sebastian , Hameiri Ziv , Hoex Bram , Aberle Armin G.
Published: October 2014

It is investigated how potential drop sheet resistance measurements of areas formed by laser-assisted doping in crystalline Si wafers are affected by typically occurring experimental factors like sample size, inhomogeneities, surface roughness, or coatings. Measurements are obtained with a collinear four point probe setup and a modified transfer length measurement setup to measure sheet resistances of laser-doped lines. Inhomogeneities in doping depth are observed from scanning electron microscope images and electron beam induced current measurements. It is observed that influences from sample size, inhomogeneities, surface roughness, and coatings can be neglected if certain preconditions are met. Guidelines are given on how to obtain accurate potential drop sheet resistance measurements on laser-doped regions.
Equivariant spectral asymptotics for h-pseudodifferential operators
Authors: Weich Tobias
Published: October 2014

We prove equivariant spectral asymptotics for h-pseudodifferential operators for compact orthogonal group actions generalizing results of El Houakmi and Helffer [“Comportement semi-classique en présence de symétries: Action d'un groupe de Lie compact,” Asymp. Anal. 5(2), 91–113 (1991)] and Cassanas [“Reduced Gutzwiller formula with symmetry: Case of a Lie group,” J. Math. Pures Appl. 85(6), 719–742 (2006)]. Using recent results for certain oscillatory integrals with singular critical sets [P. Ramacher, “Singular equivariant asymptotics and Weyl's law: On the distribution of eigenvalues of an invariant elliptic operator,” J. Reine Angew. Math. (Crelles J.) (to be published)], we can deduce a weak equivariant Weyl law. Furthermore, we can prove a complete asymptotic expansion for the Gutzwiller trace formula without any additional condition on the group action by a suitable generalization of the dynamical assumptions on the Hamilton flow.
Anomalous magnetism and normal field instability in supercooled liquid cobalt
Authors: Wang Jun , Li Jinshan , Hu Rui , Kou Hongchao , Beaugnon Eric
Published: October 2014

Supercooled liquids may offer fascinating phenomena as compared with the normal state. In the case of supercooled paramagnetic liquids, completely different phenomena in high magnetic fields should be observed thanks to the high undercooling leading to higher magnetization and very strong magnetic coupling in the liquids. Here, we report the measurement of an undercooled pure liquid metal with a higher magnetization than the solid at the same temperature. We also observe the normal field instability pattern formation in the undercooled melt. Although the origin of the high magnetism of the liquid remains unclear, we discuss the possibility of a short range ordering effect.
Motionless system to measure relative angular emission intensity of decaying or modulated light emitting diodes
Authors: Radziwon M. , Hernandez-Sosa G. , Lackner C. , Sitter H. , Simbrunner C.
Published: October 2014

In this paper, a measurement system is presented which enables fast and accurate determination of the relative angular emission intensity of light emitting devices, taking into account their specific features such as low light output, narrow spectral distribution, high spatial luminous intensity ratios, and small dimensions. Application of logarithmic sensors allows for fast measurement of relative emission by simple analog circuitry, while locating 18 of them on a fixed ring around the emitter allows a motionless measurement system. As a result, the proposed system can determine the relative angular emission in less than 100 ms with a resolution of 5° for symmetric emitters.
Optical index measurement of InAs/GaSb type-II superlattice for mid-infrared photodetection at cryogenic temperatures
Authors: Steveler E. , Verdun M. , Portier B. , Chevalier P. , Dupuis C. , Bardou N. , Rodriguez J.-B. , Haïdar R. , Pardo F. , Pelouard J.-L.
Published: October 2014

The complex optical index ñ (=n + i κ) of InAs/GaSb type-II superlattice (T2SL) was determined in the 1–6 μm range from reflectivity measurements of resonant structures at 80 K. Several air/superlattice/gold cavities of various thicknesses were fabricated and their reflectivity was measured. As the large variations induced by the cavity resonances in the studied range can be accurately modeled, we were able to determine the complex optical index ñ of InAs/GaSb T2SL with an error of only a few percent. We found that the in-plane refractive index n of the T2SL lies between 3.65 and 3.77 in the mid-infrared wavelength range, and the absorption coefficient κ decreases from 0.23 to 0.001 as the wavelength increases from 1.25 to 5.65 μm. The subtractive Kramers-Kronig relation allowed us to verify our determination of ñ.
Quantifying spatio-temporal dynamics of biomarker pre-concentration and depletion in microfluidic systems by intensity threshold analysis
Authors: Rohani Ali , Varhue Walter , Su Yi-Hsuan , Swami Nathan S.
Published: October 2014

Microfluidic systems are commonly applied towards pre-concentration of biomarkers for enhancing detection sensitivity. Quantitative information on the spatial and temporal dynamics of pre-concentration, such as its position, extent, and time evolution are essential towards sensor design for coupling pre-concentration to detection. Current quantification methodologies are based on the time evolution of fluorescence signals from biomarkers within a statically defined region of interest, which does not offer information on the spatial dynamics of pre-concentration and leads to significant errors when the pre-concentration zone is delocalized or exhibits wide variations in size, shape, and position over time under the force field. We present a dynamic methodology for quantifying the region of interest by using a statistical description of particle distribution across the device geometry to determine the intensity thresholds for particle pre-concentration. This method is applied to study the delocalized pre-concentration dynamics under an electrokinetic force balance driven by negative dielectrophoresis, for aligning the pre-concentration and detection regions of neuropeptide Y, and for quantifying the polarizability dispersion of silica nano-colloids with frequency of the force field. We envision the application of this automated methodology on data from 2D images and 3D Z-stacks for quantifying pre-concentration dynamics over delocalized regions as a function of the force field.
High-power InGaAs/GaAs quantum-well laser with enhanced broad spectrum of stimulated emission
Authors: Wang Huolei , Yu Hongyan , Zhou Xuliang , Kan Qiang , Yuan Lijun , Chen Weixi , Wang Wei , Ding Ying , Pan Jiaoqing
Published: October 2014

We report the demonstration of an InGaAs/GaAs quantum well (QW) broadband stimulated emission laser with a structure that integrated a GaAs tunnel junction with two QW active regions. The laser exhibits ultrabroad lasing spectral coverage of ∼51 nm at a center wavelength of 1060 nm with a total emission power of 790 mW, corresponding to a high average spectral power density of 15.5 mW/nm, under pulsed current conditions. Compared to traditional lasers, this laser with an asymmetric separate-confinement heterostructure shows broader lasing bandwidth and higher spectral power density.
Single mode terahertz quantum cascade amplifier
Authors: Ren Y. , Wallis R. , Shah Y. D. , Jessop D. S. , Degl'Innocenti R. , Klimont A. , Kamboj V. , Beere H. E. , Ritchie D. A.
Published: October 2014

A terahertz (THz) optical amplifier based on a 2.9 THz quantum cascade laser (QCL) structure has been demonstrated. By depositing an antireflective coating on the QCL facet, the laser mirror losses are enhanced to fully suppress the lasing action, creating a THz quantum cascade (QC) amplifier. Terahertz radiation amplification has been obtained, by coupling a separate multi-mode THz QCL of the same active region design to the QC amplifier. A bare cavity gain is achieved and shows excellent agreement with the lasing spectrum from the original QCL without the antireflective coating. Furthermore, a maximum optical gain of ∼30 dB with single-mode radiation output is demonstrated.
Microfluidic generation of droplet interface bilayer networks incorporating real-time size sorting in linear and non-linear configurations
Authors: Carreras P. , Law R. V. , Brooks N. , Seddon J. M. , Ces O.
Published: October 2014

In this study, a novel droplet based microfluidic method for the generation of different sized droplet interface bilayers is reported. A microfluidic platform was designed, which allows the generation and packing of picoliter lipid coated water droplets. Droplets were generated by hydrodynamic focusing coupled with selective transport along grooves according to their size. A trapping structure at the end of the groove and a fine control of the flow pressures allowed for the droplets to be successfully trapped and aligned on demand. This technology facilitates the fine control of droplet size production as well as the generation of extended networks from a variety of lipids including 1,2-diphytanoyl-sn-glycero-3-phosphocholine and 1,2-dioleoyl-sn-glycero-3-phosphocholine in linear and non-linear configurations, which is vital to the application of Droplet Interface Bilayers to biological network construction on-chip.
Large mode-volume, large beta, photonic crystal laser resonator
Authors: Dezfouli Mohsen Kamandar , Dignam Marc M.
Published: October 2014

We propose an optical resonator formed from the coupling of 13, L2 defects in a triangular-lattice photonic crystal slab. Using a tight-binding formalism, we optimized the coupled-defect cavity design to obtain a resonator with predicted single-mode operation, a mode volume five times that of an L2-cavity mode and a beta factor of 0.39. The results are confirmed using finite-difference time domain simulations. This resonator is very promising for use as a single mode photonic crystal vertical-cavity surface-emitting laser with high saturation output power compared to a laser consisting of one of the single-defect cavities.
Current oscillations as a manifestation of spatio-temporal inhomogeneity of temperature distribution in vanadium dioxide films at semiconductor-metal phase transition
Authors: Aliev V. Sh. , Bortnikov S. G. , Mzhelskiy I. V. , Badmaeva I. A.
Published: October 2014

A spatial temperature distribution in VO2 film was first investigated at current oscillations using infrared microscope. The oscillations are revealed to arise from the periodic formation and disappearance of a narrow high-temperature channel in VO2 film. The nature of the oscillations in VO2 films is considered from the standpoint of a well-known phenomenon: spatio-temporal instability of current flow in homogeneous semiconductors. The temperature of the channel significantly exceeds the semiconductor-metal transition temperature being the cause of film destruction and oscillations cessation.
Bio-Geo-Graphy: Landscape, Dwelling, and the Political Ecology of Human-Elephant Relations
Authors: Barua Maan
Published: October 2014

The relation between the bio and the geo has been amongst geography's most enduring concerns. This paper contributes to ongoing attempts in human geography to politicise the dynamics and distribution of life. Drawing upon postcolonial environmental history, animal ecology, and more-than-human geography, the paper examines how humans and elephants cohabit with and against the grain of cartographic design. Through fieldwork in northeast India, it develops a ‘dwelt political ecology’ that reanimates landscape as a dwelt achievement whilst remaining sensitive to postcolonial histories and subaltern concerns. The paper conceptualises and deploys a methodology of ‘tracking’ through which archival material, elephant ecology, and voices of the marginalised can be integrated and mapped. It concludes by discussing the implications of this work for fostering new conversations between more-than-human geography and subaltern political ecology.
Structures and Photoluminescence Properties of Four Cadmium(II) Coordination Polymers Synthesized by Rigid Ligands and N-Donor Ligands
Authors: Meng Qing-Guo , Wang Lin-Tong , Lu Ji-Tao , Wang Xin , Lu Wei , Song Zi-Yu
Published: October 2014

Four metal–organic coordination polymers, [Cd2(dna)2(2,2′-bpy)2]n (1), {[Cd4(dna)4(im)3]·5H2O}n (2), {[Cd2(dna)2(4,4′-bpy)(H2O)2]·2EtOH}n (3), and {[Cd4(dna)4(1,3-dpp)4(H2O)4]·2H2O}n (4) (H2dna = 4,6-dimethyl-5-nitroisophthalic acid; 2,2′-bpy = 2,2′-bipyridine; im = imidazole; 4,4′-bpy = 4,4′-bipyridine; 1,3-dpp = 1,3-di(4-pyridyl)propane; and EtOH = ethanol, have been solvothermally synthesized and characterized. Compound 1 displays a one-dimensional (1D) ladder structure and the neighbouring ladders are further stabilized by π···π interactions to form a two-dimensional (2D) layer. Compound 2 forms a 2D layer based on infinite 1D [Cd2(COO)4]n chain and the im ligands act as terminal ligands, preventing expansion of the dimensionality. Compound 3 features a 2D 44-sql layer based on binuclear [Cd2(COO)4] secondary building units as 4-connected nodes, and is further linked to be an unusual three-dimensional (3D) supramolecular architecture by hydrogen bonds involving the coordinated water molecules, carboxylate groups, and lattice ethanol molecules. Compound 4 possesses a 2-fold interpenetrated dia net. The diverse structures and topologies of compounds 1–4 indicate that the N-containing ligands have significant effects on the formation of the final network structures. In addition, the thermal stabilities, structure comparison, and photoluminescence properties of the complexes have been investigated.
Simulation of water-limited growth of the forage shrub saltbush (Atriplex nummularia Lindl.) in a low-rainfall environment of southern Australia
Authors: Descheemaeker K. , Smith A. P. , Robertson M. J. , Whitbread A. M. , Huth N. I. , Davoren W. , Emms J. , Llewellyn R.
Published: October 2014

Old man saltbush (Atriplex nummularia Lindl.) is a useful forage shrub for livestock in the low-rainfall areas of the world, and particularly in Australia. In these semi-arid and arid environments, saltbush is valuable for increasing the production from otherwise marginal areas of the farm and during drought periods when there are few feed alternatives. The ability to predict the growth and development of perennial forages such as old man saltbush in response to rainfall, soils and farm management is necessary for farming system planning and design purposes. A field experiment was conducted at Waikerie, South Australia, to inform the development of a new forage shrub model for use in the APSIM framework. The model takes into account the common setup of saltbush plantations in alley systems, by simulating light interception and water uptake for interacting shrub and inter-row zones separately. This is done by modelling the canopy and root system development. Field data across three soil types along a landscape catena showed that the model was able to satisfactorily predict daily biomass accumulation, partitioning into leaf and woody biomass, and regrowth after grazing. The model was sensitive to properties associated with the root system, and with limited parameterisation can be tailored to simulate different clonal cultivars. The model can now be used in the APSIM framework to assess temporal and spatial dynamics of forage systems combining shrubs with herbaceous pasture components.
A review of pasture establishment by undersowing with special reference to the mixed farming zone of south-eastern Australia
Authors: McCormick Jeff I. , Hayes Richard C. , Li Guangdi D. , Norton Mark R.
Published: October 2014

Pastures continue to provide essential functions for the mixed-farming zone in south-eastern Australia, where crop and livestock production are integral parts of most farms. Establishment of pastures in this zone needs to be low-cost and preferably with minimal risk. Pastures are typically sown either directly or in combination with a cover-crop (also called undersowing; the practice of sowing pasture seed simultaneously with a crop that is intended for grain production in the first year), so that the establishment cost is offset by income from the sale of grain. The purposes of this review are to: (i) draw together the literature on undersowing pastures, including studies conducted since the previous review in 1965; (ii) understand why there is a discrepancy between research results that generally do not support the practice of undersowing pastures, whereas farmer preference appears to establish pastures under a cover-crop; and (iii) identify critical needs for further research to aid in making decisions about pasture establishment on-farm. Published and unpublished data from the Australian wheatbelt on establishing pastures by undersowing was examined from the 1920s to the present and included seven publications for perennial species from 26 different experiments. Eight publications addressing establishment of annual species were available from 30 experiments. Many trials appear to have been conducted without being analysed or published. A further 16 international publications were reviewed. Generally, cover-crops reduced annual pasture seedset and perennial density even though the pastures established under the cover-cropping were commonly deemed ‘satisfactory’ by the authors. Pasture establishment was improved by reducing the sowing rate of the cover-crop and/or sowing on alternate rows. Technological change during the past 25 years has led to different configurations of seeding machinery, increased use of herbicides and longer cropping phases. Conclusions previously reached may therefore need to be re-assessed. No data published quantified the risks associated with undersowing on a seasonal and regional basis to determine the probability of success, and there are insufficient data to model the complex physiological interactions between crop and pasture, with most experiments focused on basic agronomic parameters. Furthermore, long-term effects of establishment method on total pasture biomass production and subsequent effects on following crops have rarely been demonstrated, because of the short time-frames in which most experiments have been conducted. Farmers in the mixed-farming zone still prefer to establish pastures under a cover-crop because of perceived financial benefit of the practice. This review identifies substantial research gaps to be addressed to improve pasture-establishment decisions.
Popper and phylogenetics, a misguided rendezvous
Authors: Vogt Lars
Published: October 2014

Popper’s falsificationism is frequently referred to as a general normative reference system in phylogenetics. Referring to falsificationism, phylogeneticists have made four central claims, including that frequency probabilities (1) cannot be used for inferring degrees of corroboration and (2) cannot be used in phylogenetics because phylogeny is a unique process, (3) likelihood methods represent verificationist approaches, and (4) the congruence test is a Popperian test. However, these claims are inconsistent with Popper’s theory. Moreover, phylogeneticists have proposed four strategies for dealing with the unfalsifiability of cladograms, including (1) interpreting re-interpretations of putative synapomorphy as homoplasy as Popperian ad hoc manoeuvres, (2) decoupling corroboration from falsification, (3) interpreting the tree with the highest likelihood as the most corroborated tree, and (4) interpreting tree hypotheses as Popperian probabilistic hypotheses that do not have to be falsifiable. These strategies are also inconsistent with Popper’s theory. Four fundamental problems and a problem with Popper’s formula for measuring degree of corroboration demonstrate that Popper’s theory does not live up to its own claims. Moreover, neither historical nor experimental sciences can be conducted in a way that is consistent with the principles of falsificationism. Therefore, phylogeneticists should stop referring to falsificationism when defending a specific methodological position.
Integrated life-cycle assessment of electricity-supply scenarios confirms global environmental benefit of low-carbon technologies
Authors: Hertwich Edgar G. , Gibon Thomas , Bouman Evert A. , Arvesen Anders , Suh Sangwon , Heath Garvin A. , Bergesen Joseph D. , Ramirez Andrea , Vega Mabel I. , Shi Lei
Published: October 2014

Significance

Life-cycle assessments commonly used to analyze the environmental costs and benefits of climate-mitigation options are usually static in nature and address individual power plants. Our paper presents, to our knowledge, the first life-cycle assessment of the large-scale implementation of climate-mitigation technologies, addressing the feedback of the electricity system onto itself and using scenario-consistent assumptions of technical improvements in key energy and material production technologies.
GABA
B(1)
receptor subunit isoforms differentially regulate stress resilience
Authors: O’Leary Olivia F. , Felice Daniela , Galimberti Stefano , Savignac Hélène M. , Bravo Javier A. , Crowley Tadhg , El Yacoubi Malika , Vaugeois Jean-Marie , Gassmann Martin , Bettler Bernhard , Dinan Timothy G. , Cryan John F.
Published: October 2014

Significance

Stress can increase susceptibility to developing psychiatric disorders, including depression. Understanding the neurobiological mechanisms underlying stress resilience and susceptibility is key to identifying novel targets for the development of more effective treatments for stress-related psychiatric disorders. Here we show that specific isoforms of GABA
B
receptor subunits differentially regulate stress resilience. Specifically, GABA
B(1a)
−/−
mice are more susceptible whereas GABA
B(1b)
−/−
mice are more resilient to stress-induced anhedonia and psychosocial stress-induced social withdrawal, two features of depression. Furthermore, GABA
B(1b)
−/−
mice were resilient to stress-induced decreases in the survival of newly born cells in the adult hippocampus, and hippocampal GABA
B(1b)
expression was increased in a genetic mouse model of depression. Taken together, GABA
B
receptor subunit isoforms may represent novel therapeutic targets for stress-related disorders.
Impact and cost-effectiveness of new tuberculosis vaccines in low- and middle-income countries
Authors: Knight Gwenan M. , Griffiths Ulla K. , Sumner Tom , Laurence Yoko V. , Gheorghe Adrian , Vassall Anna , Glaziou Philippe , White Richard G.
Published: October 2014

Significance

To aid in prioritizing the development of tuberculosis (TB) vaccines most likely to reach the 2050 TB elimination goal, we estimated the impact and cost-effectiveness of a range of vaccine profiles in low- and middle-income countries. Using mathematical modeling, we show that vaccines targeted at adolescents/adults could have a much greater impact on the TB burden over a 2024–2050 time horizon than those vaccines targeted at infants. Such vaccines could also be cost-effective, even with relatively high vaccine prices. Our results suggest that to achieve the 2050 elimination goals, future TB vaccine development should focus on vaccines targeted at adolescents/adults, even if only relatively low efficacies and short durations of protection are technically feasible.
Mapping of transcription factor motifs in active chromatin identifies IRF5 as key regulator in classical Hodgkin lymphoma
Authors: Kreher Stephan , Bouhlel M. Amine , Cauchy Pierre , Lamprecht Björn , Li Shuang , Grau Michael , Hummel Franziska , Köchert Karl , Anagnostopoulos Ioannis , Jöhrens Korinna , Hummel Michael , Hiscott John , Wenzel Sören-Sebastian , Lenz Peter , Schneider Markus , Küppers Ralf , Scheidereit Claus , Giefing Maciej , Siebert Reiner , Rajewsky Klaus , Lenz Georg , Cockerill Peter N. , Janz Martin , Dörken Bernd , Bonifer Constanze , Mathas Stephan
Published: October 2014

Significance

Human lymphomas and leukemias are characterized by molecular and structural alterations of transcription factors (TFs). The identification of such deregulated TFs is therefore central to the understanding of lymphomagenesis. We addressed this question in classical Hodgkin lymphoma (HL), a common B-cell–derived malignancy that is one of the most prominent examples for complex patterns of deregulated TFs including the activation of NF-κB or AP-1 and a profound deregulation of lineage-specific TFs. We found that IRF5 together with NF-κB induces a number of HL characteristic features in non-Hodgkin cells, such as expression of cytokines and chemokines or AP-1 activation. Our work exemplifies how the global lymphoma type-specific characterization of TF activities can improve the understanding of tumor biology.
Single-molecule packaging initiation in real time by a viral DNA packaging machine from bacteriophage T4
Authors: Vafabakhsh Reza , Kondabagil Kiran , Earnest Tyler , Lee Kyung Suk , Zhang Zhihong , Dai Li , Dahmen Karin A. , Rao Venigalla B. , Ha Taekjip
Published: October 2014

Significance

Tailed bacteriophages and herpes viruses use powerful molecular machines to package their genomes into a viral capsid using ATP as fuel. Recent biophysical and structural studies have provided a detailed picture of mechanochemistry of DNA packaging. However, little is known about the packaging initiation step owing to its transient nature. Here, we reconstituted the bacteriophage T4 DNA packaging machine and imaged individual packaging events in real time. We discovered that initiations occur in bursts and through multiple pathways, including direct capture of DNA by the capsid portal, and they require rapid input of energy, analogous to the cranking of an engine. This system opens a new window into the mechanism of viral genome packaging initiation and the evolution of icosahedral viruses.
Exome sequencing identifies FANCM as a susceptibility gene for triple-negative breast cancer
Authors: Kiiski Johanna I. , Pelttari Liisa M. , Khan Sofia , Freysteinsdottir Edda S. , Reynisdottir Inga , Hart Steven N. , Shimelis Hermela , Vilske Sara , Kallioniemi Anne , Schleutker Johanna , Leminen Arto , Bützow Ralf , Blomqvist Carl , Barkardottir Rosa B. , Couch Fergus J. , Aittomäki Kristiina , Nevanlinna Heli
Published: October 2014

Significance

The major portion of hereditary breast cancer still remains unexplained, and many susceptibility loci are yet to be found. Exome sequencing of 24 high-risk familial
BRCA1/2
-negative breast cancer patients and further genotyping of a large sample set of breast/ovarian cancer cases and controls was used to discover previously unidentified susceptibility alleles and genes. A significant association of a
FANCM
nonsense mutation with breast cancer, especially triple-negative breast cancer, identifies
FANCM
as a breast cancer susceptibility gene. Identification of such risk alleles is expected to improve cancer risk assessment for breast cancer patients and families, and may lead to improvements in the prevention, early diagnosis, and treatment of cancer.
The high heritability of educational achievement reflects many genetically influenced traits, not just intelligence
Authors: Krapohl Eva , Rimfeld Kaili , Shakeshaft Nicholas G. , Trzaskowski Maciej , McMillan Andrew , Pingault Jean-Baptiste , Asbury Kathryn , Harlaar Nicole , Kovas Yulia , Dale Philip S. , Plomin Robert
Published: October 2014

Significance

Differences among children in educational achievement are highly heritable from the early school years until the end of compulsory education at age 16, when UK students are assessed nationwide with standard achievement tests [General Certificate of Secondary Education (GCSE)]. Genetic research has shown that intelligence makes a major contribution to the heritability of educational achievement. However, we show that other broad domains of behavior such as personality and psychopathology also account for genetic influence on GCSE scores beyond that predicted by intelligence. Together with intelligence, these domains account for 75% of the heritability of GCSE scores. These results underline the importance of genetics in educational achievement and its correlates. The results also support the trend in education toward personalized learning.
Role for
LSM
genes in the regulation of circadian rhythms
Authors: Perez-Santángelo Soledad , Mancini Estefanía , Francey Lauren J. , Schlaen Ruben Gustavo , Chernomoretz Ariel , Hogenesch John B. , Yanovsky Marcelo J.
Published: October 2014

Significance

There is increasing evidence that previously considered core constituents of multi-subunit complexes involved in RNA processing play regulatory rather than passive roles in the control of gene expression, but specific signaling pathways in which they participate are not known. Here we show that SM-like (
LSM
) genes, which encode core components of the spliceosome, are regulated by the circadian clock and control clock function in plants and mammals, revealing convergent evolutionary mechanisms mediating posttranscriptional regulation of circadian networks across kingdoms.
Part-crystalline part-liquid state and rattling-like thermal damping in materials with chemical-bond hierarchy
Authors: Qiu Wujie , Xi Lili , Wei Ping , Ke Xuezhi , Yang Jihui , Zhang Wenqing
Published: October 2014

Significance

Materials with chemical-bond hierarchy may have a specially mixed part-crystalline part-liquid state and show nontraditional thermal transports beyond the traditional “small-parameter” lattice dynamics approach, especially the rattling-like thermal damping and thus an unusual lattice thermal conductivity that can only be described by including an effective “resonant” phonon scattering.
Cold and hunger induce diurnality in a nocturnal mammal
Authors: van der Vinne Vincent , Riede Sjaak J. , Gorter Jenke A. , Eijer Willem G. , Sellix Michael T. , Menaker Michael , Daan Serge , Pilorz Violetta , Hut Roelof A.
Published: October 2014

Significance

The circadian system drives daily rhythms in physiology and behavior. Mammals in nature can change their daily activity rhythms, but causes and consequences of this behavioral plasticity are unknown. Here we show that nocturnal mice become diurnal when challenged by cold or hunger. Negative energy balance changes hormonal, physiological and behavioral rhythms without modifying the rhythm of the circadian pacemaker in the suprachiasmatic nucleus. This response is adaptive because activity during daytime warmth and resting in a buffered environment during the cold nighttime generally reduces energy expenditure. This mechanism may explain why nighttime activity in humans generally evokes higher energy uptake and subsequent obesity and metabolic syndrome, as seen in late chronotypes and night shift workers.
Dissociation of Mechanisms Involved in Dogs’ Oriented Displacements
Authors: Chapuis N. , Thinus-Blanc C. , Poucet B.
Published: October 2014

Factors determining spatial choice were studied in experiments conducted outdoors. Six dogs (Breton spaniel) had to choose between two paths leading to a baited feeding bowl (goal). Transparent or opaque screens were interposed between the starting-point and the goal; their arrangement was devised so as to control the length and the angular deviation or divergence of the paths. The results show that when the goal was visible (transparent screens) dogs preferred the less divergent path indicating that angular deviation was the most relevant variable. When the goal was hidden (opaque screen), they preferred the shorter path and did not take into account the angular deviation. These results suggest that two classes of mechanism underlie the selection of path in these spatial situations.
Irrelevant Incentive Learning during Instrumental Conditioning: The Role of the Drive-Reinforcer and Response-Reinforcer Relationships
Authors: Dickinson Anthony , Nicholas D. J.
Published: October 2014

Four experiments investigated the processes by which a motivationally-induced change in the value of the training reinforcer affects instrumental performance. Initially, thirsty rats were trained to lever press for either a sodium or non-sodium solution. In Experiment I sodium-trained rats responded faster in extinction following the induction of a sodium appetite, but not following either food or water deprivation. Thus, enhanced extinction performance depends upon the relevance of the training reinforcer to the test drive state. The remaining experiments examined the role of the instrumental contingency. Animals received response-contingent presentations of one solution alternated either within (Experiments II and III) or between sessions (Experiment IV) with non-contingent presentations of another solution. Neither procedure yielded convincing evidence that contingent sodium presentations generated more responding in extinction under a sodium appetite than did non-contingent sodium presentations. On the basis of these results, we argue that the instrumental contingency itself does not play a major role in this irrelevant incentive effect.
Behavioural Inhibition and the Age at Social Isolation in Rats
Authors: Dalrymple-Alford J. C. , Benton David
Published: October 2014

Rats that were socially isolated or group-housed at weaning were re-housed at 51 days of age in either the same housing condition or the opposite housing condition until 91 days and throughout subsequent behavioural testing. Increased resistance to extinction of running in an alley and poorer Hebb-Williams maze learning were found only after social isolation between 23 and 51 days of age. In contrast, slower running to reach the water reward during alley training and lower rearing activity at the beginning of open field testing were evident only in rats that were isolated at the time of testing. As in previous studies, open field hyperactivity was found in rats isolated at weaning but slower emergence latency was found in animals isolated at the time of testing. These findings confirm that the many behavioural effects of social isolation at different ages do not reflect a unitary aetiology. The behaviour of rats isolated at weaning is suggestive of a “disinhibition syndrome” but the precise nature of this syndrome is as yet unclear.
Attenuation of Latent Inhibition by Post-Acquisition Reminder
Authors: Kasprow Wesley J. , Catterson Doreen , Schachtman Todd R. , Miller Ralph R.
Published: October 2014

Using lick suppression by water-deprived rats as an associative index, white noise-footshock pairings resulted in less manifest conditioning when repeated non-reinforced presentations of the white noise preceded conditioning than when no stimulus pre-exposure was given, i.e., latent inhibition was observed. However, the latent inhibition deficit was reduced in animals who received as a reminder treatment shock-alone presentations in another context during the retention interval. Animals conditioned without prior stimulus pre-exposure and those exposed to the white noise and shock unpaired during the conditioning phase of the study showed no change in lick suppression as a result of the reminder treatment. These results suggest that the behavioural deficit produced by non-reinforced pre-exposure to the to-be-conditioned stimulus arises at least in part from a reversible retrieval failure rather than a lack of acquisition.
Reversal Learning by Fornix-Transected Monkeys
Authors: Gaffan David , Harrison Susan
Published: October 2014

Experiment 1 examined visual reversal learning and in Experiment 2 monkeys were trained to criterion in a serial reversal set between “FR” and “DRO” response requirements. In both cases impairments were observed in fornix-transected monkeys. These results are discussed in connection with previous findings that in serial reversals damage to the hippocampal system in monkeys causes a deficit in spatial but not in visual learning. A unified account is proposed.
Disruption of Short-Term Memory for Reinforcement by Ambient Illumination
Authors: Colwill Ruth M.
Published: October 2014

Pigeons were trained on a delayed conditional discrimination (DCD) in which choice of one of two simultaneously presented stimuli was reinforced if the trial had been initiated by presentation of a food sample. On trials in which no sample was presented, choice of the other colour was reinforced. Illumination of the houselights during the retention interval was provided in an attempt to interfere with retention of information about the food sample which served as a conditional cue. In two experiments, retention interval illumination produced a greater disruption of DCD performance on no sample trials than on food sample trials. The finding that retention interval illumination disrupts DCD performance on no sample trials suggests that this manipulation does not affect memorial processes since there was good evidence that performance on no sample trials did not depend on remembering what happened at the outset of the trial. Furthermore, the magnitude of the disruption was larger if the illumination immediately preceded the choice stimuli than if it followed presentation of the sample stimuli. These results support the hypothesis that retention interval illumination disrupts DCD performance by interfering with discriminative control of the choice response rather than with memorial processes. In neither study did retention interval illumination impair discriminative autoshaping to keylight stimuli that immediately preceded the food sample and no sample DCD trials.
Observing Responses in Rats: Support for the Secondary Reinforcement Hypothesis
Authors: Preston G. C.
Published: October 2014

Rats’ lever presses on a retractable lever earned brief presentations of discriminative stimuli signalling periods in which responding on an alternative lever was either non-reinforced (extinction) or reinforced on a random ratio schedule. The predictions of two theoretical accounts of this behaviour were tested by studying the effects of omitting either the stimulus signalling the reinforced or that signalling the non-reinforced schedule component. Under these conditions rats’ behaviour is determined by the conditioned, affective properties of the stimuli rather than by their purely informational properties.
Interactions among Emergent Relations during Equivalence Class Formation
Authors: Fields Lanny , Adams Barbara J. , Newman Sandra , Verhave Thom
Published: October 2014

The interactions among symmetry, transitivity, and equivalence tests during the formation of 3-member equivalence classes were studied with 14 college students. After training AB and BC, a test with BA, CB, AC, and CA was conducted concurrently. Failure led to serial testing with probes for CA equivalence, BA symmetry, CA equivalence, CB symmetry, CA equivalence, AC transitivity, and CA equivalence. For five subjects, equivalence tests were passed immediately once BA and CB symmetry as well as AC transitivity had been induced. Thus, symmetry and transitivity were precursors for successful performance on equivalence tests. The conjoint function of symmetry and transitivity was assessed with the equivalence probes. As the equivalence probes were passed immediately, the presence of symmetry alone and transitivity alone were sufficient for their conjoint function without additional intervention. For different subjects, transitivity alone and symmetry were induced either directly with BA, CB, or AC probes or indirectly with equivalence probes. Equivalence probes can also induce various combinations of symmetry and transitivity. Thus, different subjects formed classes in various patterns at different rates.
Increased Responding to Female Stimuli as a Result of Sexual Experience: Tests of Mechanisms of Learning
Authors: Domjan Michael , Akins Chana , Vandergriff Danny H.
Published: October 2014

Sexual experience increases the response of males to stimuli provided by female conspecifics in a variety of species. The mechanisms of learning involved in this type of phenomenon were explored in two experiments with Japanese quail. The results indicated that instrumental conditioning with copulatory opportunity is not necessary for the acquisition of responding to female cues, and responding is not facilitated by learning about the location of the female. However, the response of males to female stimuli (as well as to arbitrary stimuli associated with access to a female) was enhanced by the presence of sexually conditioned contextual cues. Substantial levels of responding also occurred to female stimuli in a context where the subjects never encountered a female quail before. This latter outcome is consistent with the possibility that stimuli from a female become directly associated with sexual reinforcement during the course of sexual experience. Similar forms of learning may be involved in the effects of sexual experience on the response of mammalian species to female odours.
The Effect of Intertrial Food Presentations on Anticipatory Goal-Tracking in the Rat
Authors: Durlach Paula J. , Shane Dairn O.
Published: October 2014

Four experiments examined the sensitivity of anticipatory goal-tracking in the rat to stimulus-food contingency. Contingency was manipulated by varying the probability of food delivery in the absence of a food-tray-light or clicker conditional stimulus (CS), while holding constant the probability of food coincident with the CS. CS control of anticipatory food tray investigation was examined after a period of context extinction in all experiments. Acquisition of stimulus control was undermined by the scheduling of intertrial food deliveries (Experiment 1). The rate of intertrial food deliveries influenced subsequent acquisition of CS control when all intertrial food deliveries were omitted (Experiment 2). When intertrial food deliveries were added to the training regimen subsequent to acquisition of CS control, that control was impaired (Experiments 3 and 4).
Natural Categorization through Multiple Feature Learning in Pigeons
Authors: Huber Ludwig , roje Nikolaus F.T , Loidolt Michaela , Aust Ulrike , Grass Dieter
Published: October 2014

Recently (Troje, Huber, Loidolt, Aust, & Fieder 1999), we found that pigeons discriminated between large sets of photorealistic frontal images of human faces on the basis of sex. This ability was predominantly based on information contained in the visual texture of those images rather than in their configural properties. The pigeons could learn the distinction even when differences of shape and average intensity were completely removed. Here, we proved more specifically the pigeons’ flexibility and efficiency to utilize the class-distinguishing information contained in complex natural classes. First, we used principal component as well as discriminant function analysis in order to determine which aspects of the male and female images could support successful categorization. We then conducted various tests involving systematic transformations and reduction of the feature content to examine whether or not the pigeons’ categorization behaviour comes under the control of categorylevel feature dimensions—that is, those stimulus aspects that most accurately divide the stimulus classes into the experimenter-defined categories of “Male” and “Female”. Enhanced classification ability in the presence of impoverished test faces that varied only along one of the first three principal components provided evidence that the pigeons used these class-distinguishing stimulus aspects as a basis for generalization to new instances.