bluuebunny/crossref_metadata_2025 huggingface dataset:
Polarization rotation and phase transition in [100]-oriented PZN-PT single crystals determined by the electro-crystalline anisotropy
Authors: Zhang Hui
Published: November 2013

We have investigated the polarization rotation and phase transition in [100]-oriented PZN-4.5%PT and PZN-8%PT single crystals on the basis of the single domain polarization rotation model. The dependence of both the polarization and the electrostrictive responses in ferroelectric crystals on the field at various temperatures has been numerically obtained. The numerical results have shown that both the polarization rotation and the phase transition are in nature determined by the electro-crystalline anisotropy constants. These constants are dependent on the composition of PZN-PT solution and ferroelectric properties of its components. Without considering the piezoelectric effect, the numerical results are in agreement with the experimental data. This paper is useful for better understanding of the polarization switching and the phase transition in ferroelectric crystals.
Shape evolution of high aspect ratio holes on Si(001) during hydrogen annealing
Authors: Sudoh K. , Hiruta R. , Kuribayashi H.
Published: November 2013

We study the dynamics of void formation through the shape evolution of high-aspect-ratio cylindrical holes in Si(001) substrates under hydrogen annealing. We compare the observed evolution of these holes with numerical simulations based on the continuum theory for surface-diffusion-driven shape evolution. We find that a strong morphological instability arises near the hole opening, regardless of the presence of anisotropy in surface energy. The observed shape evolution of high-aspect-ratio holes during hydrogen annealing is understood as a surface-diffusion-driven evolution subject to the stability of the facets which form the vertical sidewall.
Edge rotational magnons in magnonic crystals
Authors: Lisenkov Ivan , Kalyabin Dmitry , Nikitov Sergey
Published: November 2013

It is predicted that in 2D magnonic crystals the edge rotational magnons of forward volume magnetostatic spin waves can exist. Under certain conditions, locally bounded magnons may appear within the crystal consisting of the ferromagnetic matrix and periodically inserted magnetic/non-magnetic inclusions. It is also shown that interplay of different resonances in 2D magnonic crystal may provide conditions for spin wave modes existence with negative group velocity.
Metallic magnetism and change of conductivity in the nano to bulk transition of cobalt ferrite
Authors: Arunkumar A. , Vanidha D. , Oudayakumar K. , Rajagopan S. , Kannan R.
Published: November 2013

Variations in conductivity with particle size have been observed in cobalt ferrite, when synthesized by solgel auto-combustion method. Impedance analysis reveals metallic and semiconducting behavior at room temperature for a particle size of 6 nm and 52 nm, respectively. Upon thermal activation, metallic to semiconducting phase transition has been observed as a function of particle size and vice-versa. Grainboundary Resistance (Rgb), increased drastically with particle size (19 MΩ for 6 nm and 259 MΩ for 52 nm) at room temperature. AC conductivity and dielectric constants exhibit similar metallic to semiconducting phase transition at 6 nm and semiconducting behavior at 52 nm with temperature in the selected frequencies. Enhanced magnetic moment with an increase in the grain size along with decreased coercivity (1444 G to 1146 G) reveals transition from single domain to multi-domain. Increased inter-particle interaction is responsible for metallicity at the nano level and on the contrary semiconductivity is attributed to bulk.
Recovery torque modeling of carbon fiber reinforced shape memory polymer nanocomposites
Authors: Shen He , Xu Yunjun , Liang Fei , Gou Jihua , Mabbott Bob
Published: November 2013

Carbon fiber and carbon nanofiber paper (CF&CNFP) can be incorporated into shape memory polymers (SMPs) to increase electrical conductivity and allow high speed electrical actuation with a low power. This paper studies the interactions among the recovery torques of CF&CNFP and SMP and the gravity torque during the shape recovery process. The proposed recovery torque model in a SMP CF&CNFP based structure is validated by experimental data obtained using a recently developed low cost, non-contact measurement testbed.
Ultrastrong coupling of intersubband plasmons and terahertz metamaterials
Authors: Dietze D. , Andrews A. M. , Klang P. , Strasser G. , Unterrainer K. , Darmo J.
Published: November 2013

We report on the ultrastrong-coupling between localized plasmons of a planar terahertz metamaterial and intersubband plasmons in a modulation doped quantum well sample. Such a system exhibits the formation of a lower and an upper polariton branch when the metamaterial eigenfrequency is tuned close to resonance with the intersubband transition. We achieve a normalized polariton splitting of 22% and a polaritonic gap of 2.4% of the intersubband transition frequency. In addition to the usual geometrical scaling, we demonstrate the effective tuning of the metamaterial resonance by dry etching with a tuning range of more than 1 THz.
Phase change in terahertz waves emitted from differently doped graphite: The role of carrier drift
Authors: Irfan Muhammad , Yim Jong-Hyuk , Kim Changyoung , Wook Lee Sang , Jho Young-Dahl
Published: November 2013

We investigate characteristics of THz waves radiated from differently doped graphite samples excited by femtosecond laser pulses. Between n-type single-crystalline graphite and p-type polycrystalline graphite films, we observe the phase reversal of THz waves regardless of excitation energy variations around K-valley. In addition, variations in other parameters such as excitation fluence and azimuthal angle produce no changes in the phase of THz waves, which correlate well with the opposite dipole polarization between differently doped samples rather than unidirectional diffusive transport.
AlGaN/GaN field effect transistors for power electronics—Effect of finite GaN layer thickness on thermal characteristics
Authors: Hodges C. , Anaya Calvo J. , Stoffels S. , Marcon D. , Kuball M.
Published: November 2013

AlGaN/GaN heterostructure field effect transistors with a 150 nm thick GaN channel within stacked AlxGa1−xN layers were investigated using Raman thermography. By fitting a thermal simulation to the measured temperatures, the thermal conductivity of the GaN channel was determined to be 60 W m−1 K−1, over 50% less than typical GaN epilayers, causing an increased peak channel temperature. This agrees with a nanoscale model. A low thermal conductivity AlGaN buffer means the GaN spreads heat; its properties are important for device thermal characteristics. When designing power devices with thin GaN layers, as well as electrical considerations, the reduced channel thermal conductivity must be considered.
Synthesis of Sabina δ-Lactones and Sabina δ-Lactams from (+)-Sabinene
Authors: Gnilka Radoslaw , Wawrzeńczyk Czeslaw
Published: November 2013

Two sabina δ-lactones (3 and 4) were obtained in a two-step synthesis from (+)-sabinene (1). The oxidation of (+)-sabinene (1) with potassium permanganate and sodium periodate to (–)-sabina ketone (2) was the first step. In the second step, the ketone obtained was subjected to chemical and microbial Baeyer–Villiger oxidation. Chemical Baeyer–Villiger oxidation of this ketone afforded two δ-lactones 3 and 4 whereas microbial Baeyer–Villiger oxidation afforded only ‘abnormal’ δ-lactone 4. (–)-Sabina ketone was also the starting material for the synthesis of new δ-lactams (7 and 8). They were obtained by Beckmann rearrangement of sabina ketone oximes 5a and 5b. An attempt to separate (–)-sabina ketone oximes 5a and 5b is also presented.
Polymer Complexation by Hydrogen Bonding at the Interface
Authors: Yang Shuguang , Ma Songmei , Wang Chunyan , Xu Jian , Zhu Meifang
Published: November 2013

Polymer complexes can form in the bulk and at interfaces. Polymer complex formation in the bulk has been studied for a long time. The recently developed layer-by-layer assembly technique well realizes polymer complexation at interfaces. The layer-by-layer assembly of polymers based on Coulomb forces or hydrogen bonding is a repeated complexation process conducted at a surface. This paper reviews both single (once only) and repeatable interfacial complexation by hydrogen bonding, the available hydrogen bonding pairs for complexation, the thermodynamics and kinetics of complexation, and construction schemes.
Bernard Yarnton Mills 1920–2011
Authors: Frater R. H. , Goss W. M. , Wendt H. W.
Published: November 2013

Bernie Mills is remembered globally as an influential pioneer in the evolving field of radio astronomy. His contributions with the ‘Mills Cross' at the CSIRO Division of Radiophysics and later at the University of Sydney's School of Physics and the development of the Molonglo Observatory Synthesis Telescope (MOST) were widely recognized as astronomy evolved in the years 1948–85 and radio astronomy changed the viewpoint of the astronomer as a host of new objects were discovered.
Nancy Fanny Millis 1922–2012
Authors: Pittard A. J.
Published: November 2013

Professor Emeritus Nancy Millis AC, MBE, FAA, FTSE died on 29 September 2012 at the age of 90. She was one of the first women to be appointed Professor at the University of Melbourne, had been President of the Australian Society for Microbiology and after her retirement was Chancellor at La Trobe University. Nancy introduced the teaching of Industrial Microbiology into Australia and by her research and involvement with various organizations promoted a continuing analysis of water utilization and the environment. She will also be remembered for her role, over twenty years, in guiding the committees responsible for overseeing the development of recombinant DNA research in Australia. Her tireless dedication to the service of others, her wit and her forthright approach endeared her to many. Nancy Millis was elected to the Australian Academy of Science in 2004 by Special Election in recognition of her conspicuous service to the cause of science with her outstanding career in Microbiology. This report chronicles some of the very significant and far-reaching contributions that Nancy made to the discipline of Microbiology and to the larger Australian community during her long and very productive life.
John Frederick Adrian Sprent 1915–2010
Authors: Bryant Chris , Beveridge Ian , Jones Malcolm , Jones Hugh I.
Published: November 2013

John Frederick Adrian Sprent was the outstanding figure in Parasitology in Australia in the twentieth century. He established and held the Chair of the Department of Parasitology at the University of Queensland from 1956 to 1983. He was internationally recognized by parasitologists, both for his work on ascaridoid nematodes and for his huge contribution as Editor-in-Chief of the International Journal for Parasitology from 1974 to 1993.
Structure, histochemistry and seasonal variations of the male reproductive accessory glands in the Pallas’s mastiff bat, Molossus molossus (Chiroptera: Molossidae)
Authors: Christante Caroline M. , Beguelini Mateus R. , Puga Cintia C. I. , Negrin Ana C. , Morielle-Versute Eliana , Vilamaior Patrícia S. L. , Taboga Sebastião R.
Published: November 2013

Due to their wide geographical distribution, bats suffer considerable influence from abiotic factors on their reproductive strategies, detected through behavioural or functional assessment of the gonads and accessory glands. The present study aimed to characterise anatomically and morphologically the reproductive accessory glands (RAGs) of Molossus molossus (Molossidae) and evaluate their seasonal variations. The RAGs were removed, fixed, sectioned after histological processing and submitted to the following stains: haematoxylin–eosin, periodic acid­–Schiff (PAS) and Gömöri’s reticulin. Our data demonstrated that the RAGs of M. molossus are composed of a semi-lobed prostatic complex associated with the urethra and a pair of inguinal bulbourethral glands. Histology and three-dimensional reconstruction of the prostatic complex demonstrated the existence of two regions: ventral and dorsal (named according to the position around the urethra). The two regions had distinctive morphological and histological differences, with the ventral region being the most prominent and the dorsal formed by four lobes. Considering the seasonal evaluation, we can infer that the prostatic complex of M. molossus is active throughout the seasons in São Paulo State (Brazil) and, although each of the prostatic regions has inherent characteristics, they synchronise to establish the main reproductive peak in spring (early rainy season).
Structural and functional insights into the regulation mechanism of CK2 by IP
6
and the intrinsically disordered protein Nopp140
Authors: Lee Won-Kyu , Son Sang Hyeon , Jin Bong-Suk , Na Jung-Hyun , Kim Soo-Youl , Kim Kook-Han , Kim Eunice EunKyeong , Yu Yeon Gyu , Lee Hyung Ho
Published: November 2013

Significance

Structural and functional studies on protein kinase CK2α, which is a ubiquitous kinase that can phosphorylate hundreds of cellular proteins, revealed that CK2α activity is inhibited by Nopp140 and reactivated by IP
6
by competitive binding at the substrate recognition site of CK2α. IP
6
binds to the lysine-rich cluster of CK2α, and phospho-Ser574 on Nopp140 significantly enhances its interaction with CK2α.
Islet amyloid polypeptide toxicity and membrane interactions
Authors: Cao Ping , Abedini Andisheh , Wang Hui , Tu Ling-Hsien , Zhang Xiaoxue , Schmidt Ann Marie , Raleigh Daniel P.
Published: November 2013

Significance

Amyloid formation is a hallmark of a range of human diseases. The polypeptide hormone amylin forms amyloid deposits in type 2 diabetes, and amyloid formation is thought to be a contributor to the decline in β-cell mass in the disease, however the basis of amylin-induced cytotoxicity is not fully understood. Amylin-induced membrane disruption has attracted considerable interest, and the interactions of amylin with model membranes have been characterized, but the relationship between studies with model membranes and toxicity is not understood. In this article the relationship between cell toxicity and the ability to disrupt model membranes is examined. There is no direct correlation between the two processes.
FtsK-dependent XerCD-
dif
recombination unlinks replication catenanes in a stepwise manner
Authors: Shimokawa Koya , Ishihara Kai , Grainge Ian , Sherratt David J. , Vazquez Mariel
Published: November 2013

Significance

Newly replicated circular chromosomes are topologically linked. XerC/XerD-
dif
(XerCD-
dif
)–FtsK recombination acts in the replication termination region of the
Escherichia coli
chromosome to remove links introduced during homologous recombination and replication, whereas Topoisomerase IV removes replication links only. Based on gel mobility patterns of the products of recombination, a stepwise unlinking pathway has been proposed. Here, we present a rigorous mathematical validation of this model, a significant advance over prior biological approaches. We show definitively that there is a unique shortest pathway of unlinking by XerCD-
dif
–FtsK that strictly reduces the complexity of the links at every step. We delineate the mechanism of action of the enzymes at each step along this pathway and provide a 3D interpretation of the results.
Persistence of hippocampal multivoxel patterns into postencoding rest is related to memory
Authors: Tambini Arielle , Davachi Lila
Published: November 2013

Significance

Memory consolidation is thought to depend on the reactivation of patterns of brain activity that characterize recent experience. Although reactivation has been identified and well-described in the rodent hippocampus, a structure critical for the formation of long-term memories, the persistence of patterns of hippocampal activity has not been investigated in humans. Using functional MRI, we find that patterns of hippocampal connectivity that characterize an encoding experience persist into immediate rest periods. Furthermore, this persistence is related to memory for the preceding representations, suggesting that postencoding measures of persistent activity patterns may contribute to memory consolidation.
Comprehensive analysis of imprinted genes in maize reveals allelic variation for imprinting and limited conservation with other species
Authors: Waters Amanda J. , Bilinski Paul , Eichten Steven R. , Vaughn Matthew W. , Ross-Ibarra Jeffrey , Gehring Mary , Springer Nathan M.
Published: November 2013

Significance

In many eukaryotes, reproduction involves contributions of genetic material from two parents. At some genes there are parent-of-origin differences in the expression of the maternal and paternal alleles of a gene and this is referred to as imprinting. The analysis of allele-specific expression in several maize hybrids allowed the comprehensive detection of imprinted genes. By comparing allelic expression patterns in multiple crosses, it was possible to observe allelic variation for imprinting in maize. The comparison of genes subject to imprinting in multiple plant species reveals limited conservation for imprinting. The subset of genes that exhibit conserved imprinting in maize and rice may play important, dosage-dependent roles in regulation of seed development.
Unexpected gain of function for the scaffolding protein plectin due to mislocalization in pancreatic cancer
Authors: Shin Soo J. , Smith Jeffrey A. , Rezniczek Günther A. , Pan Sheng , Chen Ru , Brentnall Teresa A. , Wiche Gerhard , Kelly Kimberly A.
Published: November 2013

Significance

We have shown that plectin, which we had previously identified as a biomarker for pancreatic ductal adenocarcinoma, has important function for tumor pathogenesis. We confirmed cell surface localization and identified the mechanism, exosomes, through which this occurs. Importantly, plectin is necessary for exosome formation and produces exosomes that are capable of promoting pancreatic tumor growth and aggression. Our results highlight the gain of function for plectin attributable to upregulation and exosomal localization in pancreatic cancer.
Peripheral subnuclear positioning suppresses
Tcrb
recombination and segregates
Tcrb
alleles from RAG2
Authors: Chan Elizabeth A. W. , Teng Grace , Corbett Elizabeth , Choudhury Kingshuk Roy , Bassing Craig H. , Schatz David G. , Krangel Michael S.
Published: November 2013

Significance

Eukaryotic genes are directed to distinct subnuclear compartments to regulate their activity. We show that different regions of the murine T-cell receptor β (
Tcrb
) locus interact independently with the nuclear lamina and that these interactions locally suppress the recombination of variable, diversity, and joining gene segments. This suppression is associated with the physical segregation of the locus from the recombinase protein, recombination-activating gene 2. Allelically excluded recombination of antigen receptor genes promotes the development of lymphocytes that each express a single antigen receptor. We propose that interaction with the nuclear lamina contributes to allelic exclusion by reducing the frequency of recombination of
Tcrb
alleles.
Emergence of spatial structure in the tumor microenvironment due to the Warburg effect
Authors: Carmona-Fontaine Carlos , Bucci Vanni , Akkari Leila , Deforet Maxime , Joyce Johanna A. , Xavier Joao B.
Published: November 2013

Significance

Cancer cells undergo dramatic metabolic alterations, such as the Warburg effect where glucose is consumed independently of oxygen, leading to high lactic acid production. Although these alterations can give growth advantages to cancer cells, they have a profound effect in the extracellular environment, and thus it is not clear how they affect healthy cells. Here we show that lactic acid accumulation can impair the survival of tumor-associated macrophages. Using a multidisciplinary combination of computational and experimental methods, we show that this decreased survival can lead to spatial patterns of macrophage localization that resemble how tumor-associated macrophages distribute in real tumors. Spatial patterns can potentiate tumor growth, and thus understanding how they are formed may bring therapeutic insights.
Structure and assembly of an inner membrane platform for initiation of type IV pilus biogenesis
Authors: Karuppiah Vijaykumar , Collins Richard F. , Thistlethwaite Angela , Gao Ya , Derrick Jeremy P.
Published: November 2013

Significance

Type IV pili are long, thin fibers, formed mainly of polymers of a single pilin protein, which are displayed on the surfaces of many bacteria, including several human pathogens. Here, we report three-dimensional reconstructions of the PilMNO inner membrane complex, alone and in complex with pilin protein, through a combination of X-ray crystallography and electron microscopy. PilMNO forms a dimeric T-shaped structure, binding two copies of the pilin protein at its extremities. The results provide a structural model for the way in which pilin is harvested from the inner membrane and made available to other components of the type IV pilus biogenesis machinery.
A unique secreted adenovirus E3 protein binds to the leukocyte common antigen CD45 and modulates leukocyte functions
Authors: Windheim Mark , Southcombe Jennifer H. , Kremmer Elisabeth , Chaplin Lucy , Urlaub Doris , Falk Christine S. , Claus Maren , Mihm Janine , Braithwaite Myles , Dennehy Kevin , Renz Harald , Sester Martina , Watzl Carsten , Burgert Hans-Gerhard
Published: November 2013

Significance

Human adenoviruses encode Early region 3 (E3) proteins that manipulate the host immune response to establish an infection or to persist longer. To date, only a few E3 functions from a single adenovirus species (C) have been characterized, all of which act directly on infected cells. Here we describe a secreted E3 protein that is uniquely expressed by species D adenoviruses. This protein targets noninfected leukocytes using a cell surface phosphatase as a receptor. We provide evidence that this interaction suppresses leukocyte activation and effector functions, implying that species D adenoviruses can affect the host distant from the site of infection.
Dynamic faces speed up the onset of auditory cortical spiking responses during vocal detection
Authors: Chandrasekaran Chandramouli , Lemus Luis , Ghazanfar Asif A.
Published: November 2013

Significance

We combine facial motion with voices to help us hear better, but the role that low-level sensory areas such as the auditory cortex may play in this process is unclear. We combined a vocalization detection task with auditory cortical physiology in monkeys to bridge this epistemic gap. Surprisingly, and contrary to previous assumptions and hypotheses, changes in firing rate had no clear relationship to the detection advantage that dynamic faces provided when listening for vocalizations. Instead, dynamic faces uniformly sped up the onset of spiking activity in the auditory cortex, and this faster onset partially explains the behavioral benefits of combining faces and voices.
Establishment of smooth muscle and cartilage juxtaposition in the developing mouse upper airways
Authors: Hines Elizabeth A. , Jones Mary-Kayt N. , Verheyden Jamie M. , Harvey Julie F. , Sun Xin
Published: November 2013

Significance

A balance of airway rigidity and elasticity is critical for uninterrupted airflow to and from the lungs. In the trachea and bronchi, this balance is achieved by the precise juxtaposition of smooth muscle (SM) and cartilage that together encircle the airway. We investigate how this juxtaposition is established during embryogenesis by using mouse mutants that lack either SM or cartilage in the developing lung. We demonstrate the nature of the antagonism between the nascent SM and cartilage lineages. Our results also reveal a role for cartilage in the proper differentiation of tracheal epithelium. Together these findings elucidate unique mechanisms of how airway SM or cartilage malformation may impact airway function.
Revised standards for statistical evidence
Authors: Johnson Valen E.
Published: November 2013

Significance

The lack of reproducibility of scientific research undermines public confidence in science and leads to the misuse of resources when researchers attempt to replicate and extend fallacious research findings. Using recent developments in Bayesian hypothesis testing, a root cause of nonreproducibility is traced to the conduct of significance tests at inappropriately high levels of significance. Modifications of common standards of evidence are proposed to reduce the rate of nonreproducibility of scientific research by a factor of 5 or greater.
Structural and genetic analyses reveal the protein SepF as a new membrane anchor for the Z ring
Authors: Duman Ramona , Ishikawa Shu , Celik Ilkay , Strahl Henrik , Ogasawara Naotake , Troc Paulina , Löwe Jan , Hamoen Leendert W.
Published: November 2013

Significance

A key step in bacterial cell division is the polymerization of FtsZ at midcell into a ring-like structure. This so-called Z ring forms a scaffold for the other cell division proteins. FtsA anchors the Z ring to the cell membrane; however, many bacterial species do not have FtsA. Here, we show that the conserved protein SepF, which forms large protein rings, also functions as a membrane anchor for the Z ring. We determined the molecular structure of the FtsZ-binding and ring-forming domain of SepF and show that the membrane-binding domain is located at the very beginning of the protein. These results explain why FtsA and SepF can fulfill similar functions in bacterial cell division.
Phage T7 Gp2 inhibition of
Escherichia coli
RNA polymerase involves misappropriation of σ
70
domain 1.1
Authors: Bae Brian , Davis Elizabeth , Brown Daniel , Campbell Elizabeth A. , Wigneshweraraj Sivaramesh , Darst Seth A.
Published: November 2013

Significance

After infection of
Escherichia coli
by bacteriophage T7, the host RNA polymerase (RNAP) produces early phage transcription products that encode the phages own RNAP (that transcribes subsequent phage genes) as well as Gp2, an essential inhibitor of the host RNAP. X-ray crystal structures of
E. coli
RNAP define the structure and location of the RNAP σ
70
subunit domain 1.1

inside the RNAP active site channel, where it must be displaced by the DNA upon formation of the transcription complex. Gp2 binds inside the RNAP active site channel and also interacts with

, preventing

from exiting the RNAP active site channel. Gp2 thus misappropriates a domain of the RNAP,

, to inhibit the function of the enzyme.
Crystal structure of the human eIF4AIII–CWC22 complex shows how a DEAD-box protein is inhibited by a MIF4G domain
Authors: Buchwald Gretel , Schüssler Steffen , Basquin Claire , Le Hir Hervé , Conti Elena
Published: November 2013

Significance

The fate of eukaryotic mRNAs is intimately linked to the complement of proteins that associate with them to form mRNA—protein complexes, the so-called messenger ribonucleoprotein particles (mRNPs). Transitions in the architecture of an mRNP lead to specific functional consequences. DEAD-box proteins are key players in orchestrating these structural rearrangements: They associate with RNA in response to ATP binding and dissociate from it upon ATP hydrolysis. In this paper, we have elucidated the molecular mechanisms by which a DEAD-box protein, which in human cells marks spliced mRNPs for a specialized surveillance pathway, is recognized by the MIF4G domain of a splicing factor. This structure shows how a MIF4G domain can act as a negative regulator of DEAD-box ATPase activity.
Growth hormone prevents the development of autoimmune diabetes
Authors: Villares Ricardo , Kakabadse Dimitri , Juarranz Yasmina , Gomariz Rosa P. , Martínez-A Carlos , Mellado Mario
Published: November 2013

Significance

Although the relationship between endocrine and immune systems is well documented, few studies have been performed on autoimmune disorders other than those that are sex hormone-related. We studied a murine model of autoimmune diabetes, showing that growth hormone (GH) modifies the immune response to render diabetic mice resistant to disease development. The mechanism involves a GH-mediated effect on β-cell survival and/or proliferation and a direct effect on immune cells. GH triggers a cytokine environment that promotes anti-inflammatory macrophage polarization, maintains the activity of the suppressor T cells, and limits Th17 cell plasticity. This study provides evidence of the importance of endocrine control of immune functions and indicates that therapies based on GH analogs should be considered for treatment of autoimmune diabetes.
Transmission of multiple system atrophy prions to transgenic mice
Authors: Watts Joel C. , Giles Kurt , Oehler Abby , Middleton Lefkos , Dexter David T. , Gentleman Steve M. , DeArmond Stephen J. , Prusiner Stanley B.
Published: November 2013

Significance

Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by the accumulation of misfolded α-synuclein protein in glial cells within the brain. Transgenic mice expressing mutant α-synuclein that were inoculated with brain homogenate from MSA patients developed clinical, biochemical, and pathological signs of a neurodegenerative disease, indicating that MSA is transmissible under certain conditions. This transmissibility is reminiscent of the human prion disorders, such as Creutzfeldt–Jakob disease, and suggests that MSA is caused by the accumulation of toxic α-synuclein prions in the brain.
Bioavailable copper modulates oxidative phosphorylation and growth of tumors
Authors: Ishida Seiko , Andreux Pénélope , Poitry-Yamate Carole , Auwerx Johan , Hanahan Douglas
Published: November 2013

Significance

This paper describes the mechanism by which copper mediates the interplay between the two energy-producing pathways, respiration and glycolysis. Many tumors produce increased levels of lactate, even when oxygen abounds, reflecting aerobic glycolysis (“Warburg effect”), whereas most normal tissues solely use respiration. We demonstrate that reducing systemic copper with a chelating drug impaired mitochondrial energy metabolism and decreased ATP levels despite induction of glycolysis. We propose that the metabolic phenotype of tumors is modulated in part by variable levels of copper in tumor microenvironment. Our work identifies copper as a tumor promoter by demonstrating that chronic exposure to elevated levels of copper in drinking water—to the maximum allowed in public water supplies—accelerates tumor growth in mice.
High-affinity olfactory receptor for the death-associated odor cadaverine
Authors: Hussain Ashiq , Saraiva Luis R. , Ferrero David M. , Ahuja Gaurav , Krishna Venkatesh S. , Liberles Stephen D. , Korsching Sigrun I.
Published: November 2013

Significance

Cadaverine and putrescine, two diamines emanating from decaying flesh, are strongly repulsive odors to humans but serve as innate attractive or social cues in other species. Here we show that zebrafish, a vertebrate model system, exhibit powerful and innate avoidance behavior to both diamines, and identify a high-affinity olfactory receptor for cadaverine.
Global methylation state at base-pair resolution of the
Caulobacter
genome throughout the cell cycle
Authors: Kozdon Jennifer B. , Melfi Michael D. , Luong Khai , Clark Tyson A. , Boitano Matthew , Wang Susana , Zhou Bo , Gonzalez Diego , Collier Justine , Turner Stephen W. , Korlach Jonas , Shapiro Lucy , McAdams Harley H.
Published: November 2013

Significance

Caulobacter crescentus
, a bacterium with an inherent asymmetric cell division, uses dynamic changes in chromosome methylation state to synchronize chromosome replication with cell-cycle regulation. We identified the N
6
-methyladenine and 5-methylcytosine methylation state of every base pair at five times in the cell cycle to show that 4,515 GANTC sites, recognized by the CcrM methyltransferase, change from full- to hemimethylation upon passage of the replication fork. Significantly, 27 of the GANTC sites are protected from methylation at all times. We also identified four previously unknown methylation motifs and the cognate methyltransferase for two of these motifs. The ability to track the state of the methylome in exquisite temporal detail will be invaluable to investigations of microbial epigenetic regulation.
Choice Both Affects and Reflects Preferences
Authors: Coppin Géraldine , Delplanque Sylvain , Bernard Charlène , Cekic Sezen , Porcherot Christelle , Cayeux Isabelle , Sander David
Published: November 2013

The free-choice paradigm is a widely used paradigm in psychology. It has been used to show that after a choice between two similarly pleasant stimuli, the pleasantness of the chosen one tends to increase, whereas the pleasantness of the rejected one tends to decrease—a spreading of alternatives. However, the methodological validity of the free-choice paradigm to study choice-induced preference change has recently been seriously questioned [Chen, K. M., & Risen, J. L. (2010). How choice affects and reflects preferences: Revisiting the free-choice paradigm. Journal of Personality and Social Psychology, 99, 573–594. doi:10.1037/a0020217]. According to this criticism, the classically reported spreading of alternatives between the first and second rating sessions cannot be unambiguously interpreted to reflect a true change in preferences and can be observed even for completely static preferences. Here, we used two measurement sequences, a classical Rating 1–choice–Rating 2 sequence and a control Rating 1–Rating 2–choice sequence, to disentangle the spreading of alternatives driven by the effect of choice from the artefactual effect highlighted by Chen and Risen. In two studies using different stimulus material (faces and odours), we find that choice has a robust modulatory impact on preferences for rejected odours, but not for chosen odours and not for faces.
Arabs and the future of oil
Authors: Khadduri Walid
Published: November 2013

The discovery of shale oil and gas in North America (the United States and Canada) is considered a ‘game changer’ in the global petroleum industry. It provides an opportunity for the United States to achieve the energy self-reliance it has sought since the 1970s. It is also expected to allow the United States, the largest petroleum consumer and importer globally, to focus its attention on maximizing the economic benefits and comparative advantages of becoming a self-reliant energy state. It could also enable the United States to reprioritize its strategic interests, sharing responsibility for the security of the oil export routes in the Gulf with its European and Asian allies, rather than shouldering that task almost single-handedly, as is presently the case. However, realization of the advantages that North American shale oil and gas discoveries are purported to bring about will depend on whether the depletion rate can be slowed down and minimized and on whether the cost of production can remain competitive compared with that of conventional hydrocarbons. It will also depend on whether the United States will allow a large percentage of its shale petroleum to be exported, rather than be consumed domestically.
Naive and memory human B cells have distinct requirements for STAT3 activation to differentiate into antibody-secreting plasma cells
Authors: Deenick Elissa K. , Avery Danielle T. , Chan Anna , Berglund Lucinda J. , Ives Megan L. , Moens Leen , Stoddard Jennifer L. , Bustamante Jacinta , Boisson-Dupuis Stephanie , Tsumura Miyuki , Kobayashi Masao , Arkwright Peter D. , Averbuch Diana , Engelhard Dan , Roesler Joachim , Peake Jane , Wong Melanie , Adelstein Stephen , Choo Sharon , Smart Joanne M. , French Martyn A. , Fulcher David A. , Cook Matthew C. , Picard Capucine , Durandy Anne , Klein Christoph , Holland Steven M. , Uzel Gulbu , Casanova Jean-Laurent , Ma Cindy S. , Tangye Stuart G.
Published: November 2013

Long-lived antibody memory is mediated by the combined effects of long-lived plasma cells (PCs) and memory B cells generated in response to T cell–dependent antigens (Ags). IL-10 and IL-21 can activate multiple signaling pathways, including STAT1, STAT3, and STAT5; ERK; PI3K/Akt, and potently promote human B cell differentiation. We previously showed that loss-of-function mutations in STAT3, but not STAT1, abrogate IL-10– and IL-21–mediated differentiation of human naive B cells into plasmablasts. We report here that, in contrast to naive B cells, STAT3-deficient memory B cells responded to these STAT3-activating cytokines, differentiating into plasmablasts and secreting high levels of IgM, IgG, and IgA, as well as Ag-specific IgG. This was associated with the induction of the molecular machinery necessary for PC formation. Mutations in IL21R, however, abolished IL-21–induced responses of both naive and memory human B cells and compromised memory B cell formation in vivo. These findings reveal a key role for IL-21R/STAT3 signaling in regulating human B cell function. Furthermore, our results indicate that the threshold of STAT3 activation required for differentiation is lower in memory compared with naive B cells, thereby identifying an intrinsic difference in the mechanism underlying differentiation of naive versus memory B cells.
Concurrent loss of Ezh2 and Tet2 cooperates in the pathogenesis of myelodysplastic disorders
Authors: Muto Tomoya , Sashida Goro , Oshima Motohiko , Wendt George R. , Mochizuki-Kashio Makiko , Nagata Yasunobu , Sanada Masashi , Miyagi Satoru , Saraya Atsunori , Kamio Asuka , Nagae Genta , Nakaseko Chiaki , Yokote Koutaro , Shimoda Kazuya , Koseki Haruhiko , Suzuki Yutaka , Sugano Sumio , Aburatani Hiroyuki , Ogawa Seishi , Iwama Atsushi
Published: November 2013

Polycomb group (PcG) proteins are essential regulators of hematopoietic stem cells. Recent extensive mutation analyses of the myeloid malignancies have revealed that inactivating somatic mutations in PcG genes such as EZH2 and ASXL1 occur frequently in patients with myelodysplastic disorders including myelodysplastic syndromes (MDSs) and MDS/myeloproliferative neoplasm (MPN) overlap disorders (MDS/MPN). In our patient cohort, EZH2 mutations were also found and often coincided with tet methylcytosine dioxygenase 2 (TET2) mutations. Consistent with these findings, deletion of Ezh2 alone was enough to induce MDS/MPN-like diseases in mice. Furthermore, concurrent depletion of Ezh2 and Tet2 established more advanced myelodysplasia and markedly accelerated the development of myelodysplastic disorders including both MDS and MDS/MPN. Comprehensive genome-wide analyses in hematopoietic progenitor cells revealed that upon deletion of Ezh2, key developmental regulator genes were kept transcriptionally repressed, suggesting compensation by Ezh1, whereas a cohort of oncogenic direct and indirect polycomb targets became derepressed. Our findings provide the first evidence of the tumor suppressor function of EZH2 in myeloid malignancies and highlight the cooperative effect of concurrent gene mutations in the pathogenesis of myelodysplastic disorders.
The gating charge should not be estimated by fitting a two-state model to a Q-V curve
Authors: Bezanilla Francisco , Villalba-Galea Carlos A.
Published: November 2013

The voltage dependence of charges in voltage-sensitive proteins, typically displayed as charge versus voltage (Q-V) curves, is often quantified by fitting it to a simple two-state Boltzmann function. This procedure overlooks the fact that the fitted parameters, including the total charge, may be incorrect if the charge is moving in multiple steps. We present here the derivation of a general formulation for Q-V curves from multistate sequential models, including the case of infinite number of states. We demonstrate that the commonly used method to estimate the charge per molecule using a simple Boltzmann fit is not only inadequate, but in most cases, it underestimates the moving charge times the fraction of the field.
Prime power terms in elliptic divisibility sequences
Authors: Mahé Valéry
Published: November 2013

We study a problem on specializations of multiples of rational points on elliptic curves analogous to the Mersenne problem. We solve this problem when descent via isogeny is possible by giving explicit bounds on the indices of prime power terms in elliptic divisibility sequences associated to points in the image of a nontrivial isogeny. We also discuss the uniformity of these bounds assuming the Hall–Lang conjecture.
Obesity and Self‐control: Food Consumption, Physical Activity, and Weight‐loss Intention
Authors: Fan Maoyong , Jin Yanhong
Published: November 2013

We find that despite a stronger intention to lose weight, overweight and obese individuals in the United States are less likely to meet the federal recommendations for fruit and vegetable consumption, energy and nutrient intakes, and physical activity than are normal‐weight individuals. By utilizing the Rotter score that measures self‐control capability, we find that obese individuals exhibit a lower degree of self‐control than normal‐weight individuals, and that this lack of self‐control is associated with poor eating and exercise behaviors, as well as increased Body Mass Index and obesity risk. We discuss three mechanisms that are regularly employed to overcome self‐control problems: physician advice, improvement in the built environment, and commitment devices. Our results suggest that knowledge‐based anti‐obesity intervention policies are likely to have limited effects.
Adaptive divergence of a transcriptional enhancer between populations ofDrosophila melanogaster
Authors: Glaser-Schmitt Amanda , Catalán Ana , Parsch John
Published: November 2013

As species colonize new habitats they must adapt to the local environment. Much of this adaptation is thought to occur at the regulatory level; however, the relationships among genetic polymorphism, expression variation and adaptation are poorly understood.Drosophila melanogaster, which expanded from an ancestral range in sub-Saharan Africa around 15 000 years ago, represents an excellent model system for studying regulatory evolution. Here, we focus on the geneCG9509, which differs in expression between an African and a European population ofD. melanogaster. The expression difference is caused by variation within a transcriptional enhancer adjacent to theCG9509coding sequence. Patterns of sequence variation indicate that this enhancer was the target of recent positive selection, suggesting that the expression difference is adaptive. Analysis of theCG9509enhancer in new population samples from Europe, Asia, northern Africa and sub-Saharan Africa revealed that sequence polymorphism is greatly reduced outside the ancestral range. A derived haplotype absent in sub-Saharan Africa is at high frequency in all other populations. These observations are consistent with a selective sweep accompanying the range expansion of the species. The new data help identify the sequence changes responsible for the difference in enhancer activity.
Many human accelerated regions are developmental enhancers
Authors: Capra John A. , Erwin Genevieve D. , McKinsey Gabriel , Rubenstein John L. R. , Pollard Katherine S.
Published: November 2013

The genetic changes underlying the dramatic differences in form and function between humans and other primates are largely unknown, although it is clear that gene regulatory changes play an important role. To identify regulatory sequences with potentially human-specific functions, we and others used comparative genomics to find non-coding regions conserved across mammals that have acquired many sequence changes in humans since divergence from chimpanzees. These regions are good candidates for performing human-specific regulatory functions. Here, we analysed the DNA sequence, evolutionary history, histone modifications, chromatin state and transcription factor (TF) binding sites of a combined set of 2649 non-coding human accelerated regions (ncHARs) and predicted that at least 30% of them function as developmental enhancers. We prioritized the predicted ncHAR enhancers using analysis of TF binding site gain and loss, along with the functional annotations and expression patterns of nearby genes. We then tested both the human and chimpanzee sequence for 29 ncHARs in transgenic mice, and found 24 novel developmental enhancers active in both species, 17 of which had very consistent patterns of activity in specific embryonic tissues. Of these ncHAR enhancers, five drove expression patterns suggestive of different activity for the human and chimpanzee sequence at embryonic day 11.5. The changes to human non-coding DNA in these ncHAR enhancers may modify the complex patterns of gene expression necessary for proper development in a human-specific manner and are thus promising candidates for understanding the genetic basis of human-specific biology.
On the possibility for Rb- and Eu-cation ordering in type-I clathrates: synthesis and homogeneity range of the novel compounds Rb8–xEux(In,Ge)46(0.6 ≤x≤ 1.8)
Authors: Schäfer Marion C. , Bobev Svilen
Published: November 2013

Studies in the Rb–Eu–In–Ge system confirm the existence of the phase Rb8−xEux(In,Ge)46(0.6 ≤x≤ 1.8), crystallizing with the cubic clathrate type-I structure. The In and Ge content can be varied, concomitant with changes in the Rb–Eu ratio. Two of the three framework sites are occupied by statistical mixtures of Ge and In atoms, while the site with the lowest multiplicity is taken by the In atoms only. Based on the three refined formulae [heptarubidium europium nonaindium heptatriacontagermanide, Rb7.39(3)Eu0.61(3)In8.88(5)Ge37.12(5), and two forms of hexarubidium dieuropium decaindium hexatriacontagermanide, Rb6.30(3)Eu1.70(3)In9.76(4)Ge36.24(4)and Rb6.24(2)Eu1.76(2)In10.16(5)Ge35.84(5)] and the explored different synthetic routes, it can be suggested that the known ternary phase Rb8In8Ge38and the hypothetical quaternary phase Rb6Eu2In10Ge36represent the boundaries of the homogeneity range. In the former limiting composition, both the (Ge,In)20and the (Ge,In)24cages are fully occupied by Rb atoms only, whereas Rb6Eu2In10Ge36has Rb atoms encapsulated in the larger tetrakaidecahedra, with Eu atoms filling the smaller pentagonal dodecahedra. For the solid solutions Rb8−xEux(In,Ge)46, Rb and Eu are statistically disordered in the dodecahedral cage, and the tetrakaidecahedral cage is only occupied by Rb atoms.
Tetrachlorido[N2,N2′-(dimethylsilanediyl)bis(N-tert-butyl-3-methylbenzimidamidato)-κ2N2,N2′]hafnium(IV)
Authors: Wang Tao , Zhao Jian-Ping , Bai Sheng-Di
Published: November 2013

The symmetric title molecule, [Hf(C26H40N4Si)Cl4], lies about a twofold rotation axis. The HfIVand Si atoms lie on the rotation axis with all other atoms being in general positions. The HfIVatom is six-coordinated by two N atoms from theN2,N2′-(dimethylsilanediyl)bis(N-tert-butyl-3-methylbenzimidamidate) ligand and four Cl−ions in a slightly distorted octahedral geometry. The two amidinate moieties are connected through the central Si atom with Si—N bond length of 1.762 (3) Å, generating the characteristic N—C—N—Si—N—C—N skeleton of a silyl-linkedansa-bis(amidine) species.
Bis(acetylacetonato-κ2O,O′)(pyridine-κN)(thiocyanato-κN)manganese(III): a redetermination using data from a single crystal
Authors: Suckert Stefan , Jess Inke , Näther Christian
Published: November 2013

In the crystal structure of the title compound, [Mn(C5H7O2)2(NCS)(C5H5N)], the Mn3+cation is coordinated by two acetylacetonate anions, one terminal thiocyanate anion and one pyridine ligand within a slightly distorted octahedron. The asymmetric unit consists of half a complex molecule with the Mn3+cation, the thiocyanate anion and the pyridine ligand located on a mirror plane. The acetylacetonate anion is in a general position. The title compound was previously described [Stultset al.(1975).Inorg. Chem.14, 722–730] but could only be obtained as a powder. Suitable crystals have now been obtained for a high-precision single-crystal structure determination.