bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single Mode, Extreme Precision Doppler Spectrographs
Authors: Schwab Christian , Leon-Saval Sergio G. , Betters Christopher H. , Bland-Hawthorn Joss , Mahadevan Suvrath 
Published: April 2014

AbstractThe ‘holy grail’ of exoplanet research today is the detection of an earth-like planet: a rocky planet in the habitable zone around a main-sequence star. Extremely precise Doppler spectroscopy is an indispensable tool to find and characterize earth-like planets; however, to find these planets around solar-type stars, we need nearly one order of magnitude better radial velocity (RV) precision than the best current spectrographs provide. Recent developments in astrophotonics (Bland-Hawthorn & Horton 2006, Bland-Hawthorn et al. 2010) and adaptive optics (AO) enable single mode fiber (SMF) fed, high resolution spectrographs, which can realize the next step in precision. SMF feeds have intrinsic advantages over multimode fiber or slit coupled spectrographs: The intensity distribution at the fiber exit is extremely stable, and as a result the line spread function of a well-designed spectrograph is fully decoupled from input coupling conditions, like guiding or seeing variations (Ihle et al. 2010). Modal noise, a limiting factor in current multimode fiber fed instruments (Baudrand & Walker 2001), can be eliminated by proper design, and the diffraction limited input to the spectrograph allows for very compact instrument designs, which provide excellent optomechanical stability. A SMF is the ideal interface for new, very precise wavelength calibrators, like laser frequency combs (Steinmetz et al. 2008, Osterman et al. 2012), or SMF based Fabry-Perot Etalons (Halverson et al. 2013). At near infrared wavelengths, these technologies are ready to be implemented in on-sky instruments, or already in use. We discuss a novel concept for such a spectrograph.
Absolute Proper Motions Outside the Plane (APOP)
Authors: Qi Zhaoxiang , Yu Yong , Smart Richard L. , Lattanzi Mario G. , Tang Zhenghong , Bucciarelli Beatrice , Vecchiato Alberto , Spagna Alessandro , McLean Brian J. 
Published: April 2014

AbstractMost of the discovered exoplanets are close to our sun. Usually their host star is with large proper motions, which is an important parameter for exoplanet searching. The first version of absolute proper motions catalog achieved based on Digitized Sky Survey Schmidt plate where outside the galactic plane |b|≥27° is presented, resulting in a zero point error less than ± 0.3 mas/yr, and the overall accuracy better than ± 4.5 mas/yr for objects brighter than RF=18.5, and ranging from 4.5 to 9.0 mas/yr for objects with magnitude 18.5<RF<20.5. The systematic errors of absolute proper motions related to the position, magnitude and color are practically all removed. The sky cover of this catalog is 22,525 degree2, the mean density is 6444 objects/degree2 and the magnitude limit is around RF=20.5.
Null Stellar Intensity Interferometry
Authors: Tan P. K. , Chia C. M. , Han W. D. , Chan A. H. , Kurtsiefer C. 
Published: April 2014

AbstractSince the discovery of the first exoplanet in 1989, though over 850 candidates have been verified (Schneider 2012), few are similar to our Earth in terms of mass and size. Hence here we would like to propose the revival and improvement of optical intensity interferometry to achieve sub-milliarcsecond resolution, which promises also to be less sensitive to weather conditions, light pollution and optomechanical alignments, yet only requiring baselines <100m.
Occultation Spectrophotometry of Extrasolar Planets with SOFIA
Authors: Angerhausen Daniel , Huber Klaus F. , Mandell Avi M. , McElwain Michael W. , Czesla Stefan , Madhusudhan Nikku , Morse Jon A. 
Published: April 2014

AbstractThe NASA/DLR Stratospheric Observatory for Infrared Astronomy (SOFIA), a 2.5-meter infrared telescope on board a Boeing 747-SP, will conduct 0.3 - 1,600 μm photometric, spectroscopic, and imaging observations from altitudes as high as 45,000 ft., where the average atmospheric transmission is greater than 80 percent. SOFIA's first light cameras and spectrometers, as well as future generations of instruments, will make important contributions to the characterization of the physical properties of exoplanets. Our analysis shows that optical and near-infrared photometric and spectrophotometric follow-up observations during planetary transits and eclipses will be feasible with SOFIA's instrumentation, in particular the HIPO-FLITECAM optical/NIR instruments. The airborne-based platform has unique advantages in comparison to ground- and space-based observatories in this field of research which we will outline here. Furthermore we will present two exemplary science cases, that will be conducted in SOFIA's cycle 1.
Direct Detection of Nearby Habitable Zone Planets Using Slicer Based Integral Field Spectrographs and EPICS on the E-ELT
Authors: Salter Graeme S. , Thatte Niranjan A. , Tecza Matthias , Clarke Fraser , Kasper Markus E. 
Published: April 2014

AbstractEarly design studies for the future Exo-Planet Imaging Camera and Specrotgraph (EPICS) on the European Extremely Large Telescope (E-ELT) show the ability to probe the region of super-Earths in the habitable zone of stars within 5pc (including Gilese 581d). However, these planets will be lost to us if the correct choice of integral field spectrograph (IFS) technology is not selected for such an instrument the ability to fit and remove the speckle noise that remains is crucial to reaching these contrasts.We conclusively demonstrate, though the use of an experimental setup producing an artificial speckle, that slicer based IFSs and post-processing using spectral deconvolution can achieve speckle rejection factors exceeding 103. Contrary to popular belief, we do not find any evidence that this choice of IFS technology limits the achievable contrast. Coupled with extreme adaptive optics and high performance coronographs, a slicer based integral field spectrograph could achieve contrasts exceeding 109, enabling these super-Earths to be detected in the habitable zone of nearby stars, making it an attractive option for the next generation of instruments being designed for the direct detection of extra solar planets.
Exoplanet Surveys at Universidad de Chile
Authors: Rojo Patricio , Jenkins James , Hoyer Sergio , Jones Matías 
Published: April 2014

AbstractWe present and highlight the first results of the three main exoplanet surveys we are currently conducting at Universidad de Chile: CHEPS, Red Giant Exoplanets (radial velocity), and TraMoS (transit lightcurves). We have several interesting candidates at the Calan-Hertfordshire Extrasolar Planet Search (CHEPS) project, which is aimed at searching for the currently missing southern bright transiting planets at a few m/s radial velocity precision. Using the same technique, we are also characterizing the planetary population in a constrained sample of Red Giant stars. The Transit Monitoring from the South (TraMoS) project is aimed both at improving transit parameters and at detecting any kind of lightcurve variability from several known southern exoplanet systems.
Discovery of a SAR11 growth requirement for thiamin’s pyrimidine precursor and its distribution in the Sargasso Sea
Authors: Carini Paul , Campbell Emily O , Morré Jeff , Sañudo-Wilhelmy Sergio A , Cameron Thrash J , Bennett Samuel E , Temperton Ben , Begley Tadhg , Giovannoni Stephen J 
Published: April 2014

Abstract
Vitamin traffic, the production of organic growth factors by some microbial community members and their use by other taxa, is being scrutinized as a potential explanation for the variation and highly connected behavior observed in ocean plankton by community network analysis. Thiamin (vitamin B1), a cofactor in many essential biochemical reactions that modify carbon–carbon bonds of organic compounds, is distributed in complex patterns at subpicomolar concentrations in the marine surface layer (0–300 m). Sequenced genomes from organisms belonging to the abundant and ubiquitous SAR11 clade of marine chemoheterotrophic bacteria contain genes coding for a complete thiamin biosynthetic pathway, except for thiC, encoding the 4-amino-5-hydroxymethyl-2-methylpyrimidine (HMP) synthase, which is required for de novo synthesis of thiamin’s pyrimidine moiety. Here we demonstrate that the SAR11 isolate ‘Candidatus Pelagibacter ubique’, strain HTCC1062, is auxotrophic for the thiamin precursor HMP, and cannot use exogenous thiamin for growth. In culture, strain HTCC1062 required 0.7 zeptomoles per cell (ca. 400 HMP molecules per cell). Measurements of dissolved HMP in the Sargasso Sea surface layer showed that HMP ranged from undetectable (detection limit: 2.4 pm) to 35.7 pm, with maximum concentrations coincident with the deep chlorophyll maximum. In culture, some marine cyanobacteria, microalgae and bacteria exuded HMP, and in the Western Sargasso Sea, HMP profiles changed between the morning and evening, suggesting a dynamic biological flux from producers to consumers.
Inference of interactions in cyanobacterial–heterotrophic co-cultures via transcriptome sequencing
Authors: Beliaev Alexander S , Romine Margie F , Serres Margrethe , Bernstein Hans C , Linggi Bryan E , Markillie Lye M , Isern Nancy G , Chrisler William B , Kucek Leo A , Hill Eric A , Pinchuk Grigoriy E , Bryant Donald A , Steven Wiley H , Fredrickson Jim K , Konopka Allan 
Published: April 2014

Abstract
We used deep sequencing technology to identify transcriptional adaptation of the euryhaline unicellular cyanobacterium Synechococcus sp. PCC 7002 and the marine facultative aerobe Shewanella putrefaciens W3-18-1 to growth in a co-culture and infer the effect of carbon flux distributions on photoautotroph–heterotroph interactions. The overall transcriptome response of both organisms to co-cultivation was shaped by their respective physiologies and growth constraints. Carbon limitation resulted in the expansion of metabolic capacities, which was manifested through the transcriptional upregulation of transport and catabolic pathways. Although growth coupling occurred via lactate oxidation or secretion of photosynthetically fixed carbon, there was evidence of specific metabolic interactions between the two organisms. These hypothesized interactions were inferred from the excretion of specific amino acids (for example, alanine and methionine) by the cyanobacterium, which correlated with the downregulation of the corresponding biosynthetic machinery in Shewanella W3-18-1. In addition, the broad and consistent decrease of mRNA levels for many Fe-regulated Synechococcus 7002 genes during co-cultivation may indicate increased Fe availability as well as more facile and energy-efficient mechanisms for Fe acquisition by the cyanobacterium. Furthermore, evidence pointed at potentially novel interactions between oxygenic photoautotrophs and heterotrophs related to the oxidative stress response as transcriptional patterns suggested that Synechococcus 7002 rather than Shewanella W3-18-1 provided scavenging functions for reactive oxygen species under co-culture conditions. This study provides an initial insight into the complexity of photoautotrophic–heterotrophic interactions and brings new perspectives of their role in the robustness and stability of the association.
The short-chain fatty acid acetate reduces appetite via a central homeostatic mechanism
Authors: Frost Gary , Sleeth Michelle L. , Sahuri-Arisoylu Meliz , Lizarbe Blanca , Cerdan Sebastian , Brody Leigh , Anastasovska Jelena , Ghourab Samar , Hankir Mohammed , Zhang Shuai , Carling David , Swann Jonathan R. , Gibson Glenn , Viardot Alexander , Morrison Douglas , Louise Thomas E , Bell Jimmy D. 
Published: April 2014

AbstractIncreased intake of dietary carbohydrate that is fermented in the colon by the microbiota has been reported to decrease body weight, although the mechanism remains unclear. Here we use in vivo11C-acetate and PET-CT scanning to show that colonic acetate crosses the blood–brain barrier and is taken up by the brain. Intraperitoneal acetate results in appetite suppression and hypothalamic neuronal activation patterning. We also show that acetate administration is associated with activation of acetyl-CoA carboxylase and changes in the expression profiles of regulatory neuropeptides that favour appetite suppression. Furthermore, we demonstrate through 13C high-resolution magic-angle-spinning that 13C acetate from fermentation of 13C-labelled carbohydrate in the colon increases hypothalamic 13C acetate above baseline levels. Hypothalamic 13C acetate regionally increases the 13C labelling of the glutamate–glutamine and GABA neuroglial cycles, with hypothalamic 13C lactate reaching higher levels than the ‘remaining brain’. These observations suggest that acetate has a direct role in central appetite regulation.
Phase synchronization between collective rhythms of fully locked oscillator groups
Authors: Kawamura Yoji 
Published: April 2014

AbstractA system of coupled oscillators can exhibit a rich variety of dynamical behaviors. When we investigate the dynamical properties of the system, we first analyze individual oscillators and the microscopic interactions between them. However, the structure of a coupled oscillator system is often hierarchical, so that the collective behaviors of the system cannot be fully clarified by simply analyzing each element of the system. For example, we found that two weakly interacting groups of coupled oscillators can exhibit anti-phase collective synchronization between the groups even though all microscopic interactions are in-phase coupling. This counter-intuitive phenomenon can occur even when the number of oscillators belonging to each group is only two, that is, when the total number of oscillators is only four. In this paper, we clarify the mechanism underlying this counter-intuitive phenomenon for two weakly interacting groups of two oscillators with global sinusoidal coupling.
Current-induced spin polarization on metal surfaces probed by spin-polarized positron beam
Authors: Zhang H. J. , Yamamoto S. , Fukaya Y. , Maekawa M. , Li H. , Kawasuso A. , Seki T. , Saitoh E. , Takanashi K. 
Published: April 2014

AbstractCurrent-induced spin polarization (CISP) on the outermost surfaces of Au, Cu, Pt, Pd, Ta and W nanoscaled films were studied using a spin-polarized positron beam. The Au and Cu surfaces showed no significant CISP. In contrast, the Pt, Pd, Ta and W films exhibited large CISP (3~15% per input charge current of 105 A/cm2) and the CISP of Ta and W were opposite to those of Pt and Pd. The sign of the CISP obeys the same rule in spin Hall effect suggesting that the spin-orbit coupling is mainly responsible for the CISP. The magnitude of the CISP is explained by the Rashba-Edelstein mechanism rather than the diffusive spin Hall effect. This settles a controversy, that which of these two mechanisms dominates the large CISP on metal surfaces.
Kinetic Magnetic Resonance Imaging of the Cervical Spine: A Review of the Literature
Authors: Lord Elizabeth L. , Alobaidan Raed , Takahashi Shinji , Cohen Jeremiah R. , Wang Christopher J. , Wang Benjamin J. , Wang Jeffrey C. 
Published: April 2014

Study Design Literature review. Objective The purpose of this study is to compile and review the body of literature related to kinetic magnetic resonance imaging (kMRI) of the cervical spine. Methods A review of literature related to kMRI was performed using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Results We included 16 prospective and retrospective studies of symptomatic and asymptomatic patients who underwent kMRI of the cervical spine. Conclusions Data suggest that kMRI is able to provide meaningful information regarding changes in the cervical spine in both normal and pathologic segments. A prospective study comparing magnetic resonance imaging and kMRI is needed to confirm clinically utility of this technology.
Controllability in protein interaction networks
Authors: Wuchty Stefan 
Published: April 2014

Significance
In human and yeast protein interaction datasets we determined minimum dominating sets (MDSets), proteins that play a role in the control of the underlying interaction webs. Such proteins are defined as optimized subsets from where each remaining protein can be immediately reached. Notably, MDSet proteins were enriched with cancer-related and virus-targeted genes. Furthermore, MDSet proteins have a higher impact on network resilience than hub proteins. Indicating their relevance for the controllability of biological networks, we also found a strong involvement in bottleneck interactions, regulatory and phosphorylation events as well as genetic interactions.
Capping protein regulatory cycle driven by CARMIL and V-1 may promote actin network assembly at protruding edges
Authors: Fujiwara Ikuko , Remmert Kirsten , Piszczek Grzegorz , Hammer John A. 
Published: April 2014

Significance
Assembly of actin filaments near the plasma membrane drives extension of the cell edge as it migrates. Cells recruit a protein machine called the Arp2/3 complex to the leading edge to initiate actin filament branches that grow and push on the membrane. Equally important, capping protein (CP) binds to and terminates polymerization of the fast-growing end of the filament. Like other aspects of actin assembly, CP is subject to regulation. Specifically, the protein V-1/myotrophin inactivates CP, while capping protein Arp2/3 myosin I linker (CARMIL) proteins moderately inhibit CP. We describe how CARMIL and V-1 cooperate in a cycle of reactions to regulate CP and promote assembly of the actin network by the Arp2/3 complex.
Thioredoxin-related protein of 14 kDa is an efficient L-cystine reductase and S-denitrosylase
Authors: Pader Irina , Sengupta Rajib , Cebula Marcus , Xu Jianqiang , Lundberg Jon O. , Holmgren Arne , Johansson Katarina , Arnér Elias S. J. 
Published: April 2014

Significance
Several functions in cells require reductive processes, i.e., the enzymatic catalysis of a transfer of electrons to specific cellular substrates. One major reductive system in the cytosol of human cells depends upon thioredoxin 1 (Trx1), which in turn is kept reduced by thioredoxin reductase 1 (TrxR1) using NADPH. In the present study it is shown that another protein in addition to Trx1, called thioredoxin-related protein of 14 kDa (TRP14), is highly efficient together with TrxR1 in catalyzing reduction of L-cystine or nitric oxide-derivatized cysteine residues. It is also shown that TRP14, in contrast to Trx1, is resistant to inactivation by hydrogen peroxide. These findings reveal that several TrxR1-dependent functions in cells may not be propelled solely by Trx1, but instead relate to activities of TRP14.
Noise differentially impacts phoneme representations in the auditory and speech motor systems
Authors: Du Yi , Buchsbaum Bradley R. , Grady Cheryl L. , Alain Claude 
Published: April 2014

Significance
Contentious debate remains regarding the role of the redundant motor activation during speech perception. In this functional MRI study, multivariate pattern analysis revealed stronger multivoxel phoneme discrimination in speech motor regions than auditory cortices when the speech phonemes were moderately degraded by noise. Our findings provide neuroimaging evidence for the sensorimotor integration account. Preserved phoneme discrimination in speech motor areas may compensate for loss of specificity in noise-impoverished speech representations, which aids speech perception under adverse listening conditions.
Third-party punishment increases cooperation in children through (misaligned) expectations and conditional cooperation
Authors: Lergetporer Philipp , Angerer Silvia , Glätzle-Rützler Daniela , Sutter Matthias 
Published: April 2014

Significance
Cooperation among humans depends upon the willingness of others to take costly action to enforce the social norm to cooperate. Such behavior is often coined third-party punishment. Here we show that third-party punishment is already effective as means to increase cooperation in children. Most importantly, we identify why this is the case. First, children expect (mistakenly) third parties to punish quite often and therefore they become more cooperative. Second, the presence of third parties lets children become (rightfully) more optimistic about the cooperation levels of the interaction partner in a simple prisoner’s dilemma game. As a reaction to more optimistic expectations, children cooperate more themselves. The experiment has been run with about 1,100 children aged 7 to 11 y.
CCR5/CD4/CXCR4 oligomerization prevents HIV-1 gp120IIIBbinding to the cell surface
Authors: Martínez-Muñoz Laura , Barroso Rubén , Dyrhaug Sunniva Y. , Navarro Gemma , Lucas Pilar , Soriano Silvia F. , Vega Beatriz , Costas Coloma , Muñoz-Fernández M. Ángeles , Santiago César , Frade José Miguel Rodríguez , Franco Rafael , Mellado Mario 
Published: April 2014

SignificanceHIV-1 enters host cells via CD4 and the coreceptors CXCR4 or CCR5. Most HIV-1 variants isolated from newly infected individuals use CCR5 (R5 strains) and infect Th1 cells, among other cell types. In ∼50% of patients, R5 strains shift to X4 strains (which use CXCR4) and infect mainly Th2 cells, leading to poor prognosis and rapid disease progression. In Th2 cells, CD4 and CXCR4 levels resemble those of Th1 cells, but they express little CCR5. We report that CCR5 expression in CD4+T cells reduced X4 strain cell entry and infection; the molecular mechanism involves CD4/CXCR4/CCR5 oligomer formation. CCR5 expression altered CD4/CXCR4 heterodimer conformation, blocking virus binding. Oligomeric complexes should thus be considered a target for reducing HIV-1 binding and infection.
Lack of testicular seipin causes teratozoospermia syndrome in men
Authors: Jiang Min , Gao Mingming , Wu Chaoming , He Hui , Guo Xuejiang , Zhou Zuomin , Yang Hongyuan , Xiao Xinhua , Liu George , Sha Jiahao 
Published: April 2014

Significance
The relationship between body fat and male reproduction is clearly seen when excess fat compromises fertility; however, potential consequences of adipose tissue paucity on fertility are unclear. We report that lack of seipin, a transmembrane protein localizing to the endoplasmic reticulum, causes both paucity of adipose tissue and male sterility. Human patients and mouse models lacking seipin in germ cells produce severely abnormal sperm because of impaired lipid distribution during sperm maturation. These defects are testis-intrinsic; scarcity of adipose tissue per se does not affect male fertility. Our work shows that two distinct organs—adipose tissue and the male germ line—depend on seipin function and that appropriate lipid distribution is essential for production of mature, functional sperm.
Enhancer RNAs participate in androgen receptor-driven looping that selectively enhances gene activation
Authors: Hsieh Chen-Lin , Fei Teng , Chen Yiwen , Li Tiantian , Gao Yanfei , Wang Xiaodong , Sun Tong , Sweeney Christopher J. , Lee Gwo-Shu Mary , Chen Shaoyong , Balk Steven P. , Liu Xiaole Shirley , Brown Myles , Kantoff Philip W. 
Published: April 2014

Significance
We report that enhancer RNAs (eRNAs), a class of long noncoding RNAs, participate in the androgen receptor (AR)-dependent looping complex that enhances spatial communication of distal enhancers and target promoters, leading to transcriptional activation events. Furthermore, our data show that KLK3 eRNA (KLK3e) selectively enhances the gene expression of AR-regulated genes, and provide evidence for a positive regulatory loop in which AR-dependent transcription is modulated by an intermediate eRNA. These findings may translate into improved RNA-based therapy (eRNA suppression) to enhance the durability of androgen deprivation therapy (ADT) and prediction of the efficacy of ADT by measuring the enhancer-derived activity (eRNA expression) in prostate tumors.