bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Resolved Kennicutt-Schmidt Law in Nearby Galaxies
Authors: Momose R. , Koda J. , Kennicutt R. C. , Egusa F. , Okumura S. K. , Calzetti D. , Liu G. , Meyer J. Donovan , Scoville N. Z. , Sawada T. , Kuno N. 
Published: March 2013

AbstractThe Kennicutt-Schmidt law (Schmidt 1959; Kennicutt 1998, hereafter K-S law) is a power law correlation between area averaged star formation rate (ΣSFR) and gas surface density (Σgas). Despite its importance, the physics that underlie this correlation has remained unclear. The power law index, N, is a prime discriminator of the mechanisms that regulate star formation and form the K-S law (e.g. Leroy et al. 2008; Tan 2010). We present a study of the resolved K-S law for 10 nearby disk galaxies using our new CO(1-0) data at 750 and 500 pc resolutions. The CO(1-0) line emission is established as a tracer of the molecular gas column density, and results in a super-linear correlation (N = 1.3 and 1.8). We discuss the cause of the discrepancy between previous studies, and the mechanism of star formation indicated from our new results.
Radiation-driven Feedback to the ISM around AGNs
Authors: Wada Keiichi 
Published: March 2013

AbstractAlthough the “donut-like” obscuring molecular torus is often postulated to explain the type-1 and -2 dichotomy in AGNs, its physical origin is still unclear. We propose a plausible mechanism to explain the formation of the geometrically and optically thick torus, i.e. radiation-driven fountain. Using 3-D hydrodynamic simulations including radiative feedback from the central source, taking into account the X-ray heating and radiation pressure on the gas, we found that a vertical circulation of gas is generated in the central few to tens parsecs. Interaction between the non-steady outflows and inflows causes the formation of a geometrically thick torus with internal turbulent motion. As a result, the AGN is obscured for a wide range of solid angles. In a quasi-steady state, the opening angles for the column density toward a black hole < 1023 cm−2 are approximately ± 30° and ± 50° for AGNs with 10% and 1% Eddington luminosity, respectively. Mass inflows through the torus coexist with the outflow and internal turbulent motion, although the average mass accretion rate to the central parsec region is about ten times smaller than the accretion rate required to maintain the assumed AGN luminosity. This implies that relatively luminous AGN activity is intrinsically intermittent or that there are other mechanisms, such as stellar energy feedback, that enhance the mass accretion to the center.
Quenching of Star Formation in Molecular Outflow Host NGC 1266
Authors: Alatalo K. , Nyland K. E. , Graves G. , Deustua S. , Young L. M. , Davis T. A. , Crocker A. F. , Bureau M. , Bayet E. , Blitz L. , Bois M. , Bournaud F. , Cappellari M. , Davies R. L. , de Zeeuw P. T. , Emsellem E. , Khochfar S. , Krajnovic D. , Kuntschner H. , McDermid R. M. , Morganti R. , Naab T. , Oosterloo T. , Sarzi M. , Scott N. , Serra P. , Weijmans A. 
Published: March 2013

AbstractWe detail the rich molecular story of NGC 1266, its serendipitous discovery within the ATLAS3D survey (Cappellari et al. 2011) and how it plays host to an AGN-driven molecular outflow, potentially quenching all of its star formation (SF) within the next 100 Myr. While major mergers appear to play a role in instigating outflows in other systems, deep imaging of NGC 1266 as well as stellar kinematic observations from SAURON, have failed to provide evidence that NGC 1266 has recently been involved in a major interaction. The molecular gas and the instantaneous SF tracers indicate that the current sites of star formation are located in a hypercompact disk within 200 pc of the nucleus (Fig. 1; SF rate ≈ 2 M⊙ yr−1). On the other hand, tracers of recent star formation, such as the Hβ absorption map from SAURON and stellar population analysis show that the young stars are distributed throughout a larger area of the galaxy than current star formation. As the AGN at the center of NGC 1266 continues to drive cold gas out of the galaxy, we expect star formation rates to decline as the star formation is ultimately quenched. Thus, NGC 1266 is in the midst of a key portion of its evolution and continued studies of this unique galaxy may help improve our understanding of how galaxies transition from the blue to the red sequence (Alatalo et al. 2011).
Detecting Gas Outflows in Type-2 AGNs Selected from the Sloan Digital Sky Survey
Authors: Bae Hyun-Jin , Woo Jong-Hak , Oh Semyeong 
Published: March 2013

AbstractEnergetic outflow from active galactic nuclei (AGNs) may play a critical role in galaxy evolution (e.g., Silk & Rees 1998). We present a velocity diagnostic for detecting gas outflow in the narrow-line region of Type-2 AGNs using line-of-sight velocity offsets of the [O iii] λ5007 and Hα emission lines with respect to the systemic velocity of stars in host galaxies (See Figure 1). We apply the diagnostics to nearby galaxies at 0.02 < z < 0.05, 3775 AGN-host and 907 star-forming galaxies as a comparison sample, which are selected from the Sloan Digital Sky Survey DR7. After obtaining a best-fit stellar population model for the continuum and a systemic velocity based on stellar lines, we subtract the stellar component to measure velocity offsets of each emission line. We find a sample of 169 AGN-host galaxies with outflow signatures, displaying a larger velocity shift of [O iii] than that of Hα, as expected in a decelerating outflow model (Komossa et al. 2008). We find that the offset velocity of [O iii] increases with Eddington ratio, suggesting that gas outflow depends on the energetics of AGN.
AGN feedback on the ISM of 3C 236
Authors: Labiano A. , García-Burillo S. , Combes F. , Usero A. , Soria-Ruiz R. , Tremblay G. , Neri R. , Fuente A. , Morganti R. , Oosterloo T. 
Published: March 2013

AbstractWe have carried out 1mm/3mm continuum and 12CO(2−1) line high resolution observations to identify the footprints of AGN feedback on 3C 236. The CO emission comes from a spatially resolved disk characterized by a regular rotating pattern. Within the limits imposed by the sensitivity and velocity coverage of our data, we do not detect any outflow signatures in the cold molecular gas. Re-inspection of optical and IR spectra, shows the presence of a previously unknown ionized gas outflow. The star-formation efficiency in 3C 236, is consistent with the value measured in normal galaxies, which follow the canonical Kennicutt-Schmidt law. This result, confirmed to hold in other young radio sources examined in this work, is in stark contrast with the factor of 10–50 lower SFE that has been claimed to characterize evolved powerful radio galaxies. The recent reactivation of the AGN in 3C 236 is a likely explanation for the early evolutionary status of its molecular disk.
A 22μm selected sample from WISE and SDSS spectra catalogs
Authors: Wen Xiao-Qing , Yin Hong-Wei 
Published: March 2013

AbstractWe cross-matched Wide-field Infrared Survey Explorer sources with the Sloan Digital Sky Survey galaxy spectroscopic catalog within 6 arcsec to produce 182798 galaxies with 22 μm signal to noise > 3. The different redshift bins of the sample show that the rest-frame 22μm luminosities increase with redshift, for rest-frame 22μm luminosities in the range of 106 − 1012 L⊙. The infrared sample is located in the blue sequence. The Seyfert fraction increases with redshift more obviously in the IR sample than in an optical control sample. The Seyfert fraction increases significantly with increasing rest-frame 22 μm luminosity below 1011 L⊙.
TRANSITIVE PRIMAL INFON LOGIC
Authors: COTRINI CARLOS , GUREVICH YURI 
Published: March 2013

AbstractPrimal infon logic was introduced in 2009 in connection with access control. In addition to traditional logic constructs, it contains unary connectives p said indispensable in the intended access control applications. Propositional primal infon logic is decidable in linear time, yet suffices for many common access control scenarios. The most obvious limitation on its expressivity is the failure of the transitivity law for implication: $x \to y$ and $y \to z$ do not necessarily yield $x \to z$. Here we introduce and investigate equiexpressive “transitive” extensions TPIL and TPIL* of propositional primal infon logic as well as their quote-free fragments TPIL0 and TPIL0* respectively. We prove the subformula property for TPIL0* and a similar property for TPIL*; we define Kripke models for the four logics and prove the corresponding soundness-and-completeness theorems; we show that, in all these logics, satisfiable formulas have small models; but our main result is a quadratic-time derivation algorithm for TPIL*.
Regulation of cytochrome P450 2e1 expression by ethanol: role of oxidative stress-mediated pkc/jnk/sp1 pathway
Authors: Jin M , Ande A , Kumar A , Kumar S 
Published: March 2013

AbstractCYP2E1 metabolizes ethanol leading to production of reactive oxygen species (ROS) and acetaldehyde, which are known to cause not only liver damage but also toxicity to other organs. However, the signaling pathways involved in CYP2E1 regulation by ethanol are not clear, especially in extra-hepatic cells. This study was designed to examine the role of CYP2E1 in ethanol-mediated oxidative stress and cytotoxicity, as well as signaling pathways by which ethanol regulates CYP2E1 in extra-hepatic cells. In this study, we used astrocytic and monocytic cell lines, because they are important cells in central nervous system . Our results showed that 100 mM ethanol significantly induced oxidative stress, apoptosis, and cell death at 24 h in the SVGA astrocytic cell line, which was rescued by a CYP2E1 selective inhibitor, diallyl sulfide (DAS), CYP2E1 siRNA, and antioxidants (vitamins C and E). Further, we showed that DAS and vitamin C abrogated ethanol-mediated (50 mM) induction of CYP2E1 at 6 h, as well as production of ROS at 2 h, suggesting the role of oxidative stress in ethanol-mediated induction of CYP2E1. We then investigated the role of the protein kinase C/c-Jun N-terminal kinase/specificity protein1 (PKC/JNK/SP1) pathway in oxidative stress-mediated CYP2E1 induction. Our results showed that staurosporine, a non-specific inhibitor of PKC, as well as specific PKCζ inhibitor and PKCζ siRNA, abolished ethanol-induced CYP2E1 expression. In addition, inhibitors of JNK (SP600125) and SP1 (mithramycin A) completely abrogated induction of CYP2E1 by ethanol in SVGA astrocytes. Subsequently, we showed that CYP2E1 is also responsible for ethanol-mediated oxidative stress and apoptotic cell death in U937 monocytic cell lines. Finally, our results showed that PKC/JNK/SP1 pathway is also involved in regulation of CYP2E1 in U937 cells. This study has clinical implications with respect to alcohol-associated neuroinflammatory toxicity among alcohol users.
Mesoscale distribution and functional diversity of picoeukaryotes in the first-year sea ice of the Canadian Arctic
Authors: Piwosz Kasia , Wiktor Józef Maria , Niemi Andrea , Tatarek Agnieszka , Michel Christine 
Published: March 2013

Abstract
Sea ice, a characteristic feature of polar waters, is home to diverse microbial communities. Sea-ice picoeukaryotes (unicellular eukaryotes with cell size &lt;3 μm) have received little attention compared with diatoms that dominate the spring bloom in Arctic first-year sea ice. Here, we investigated the abundance of all picoeukaryotes, and of 11 groups (chlorophytes, cryptophytes, bolidophytes, haptophytes, Pavlovaphyceae, Phaeocystis spp., pedinellales, stramenopiles groups MAST-1, MAST-2 and MAST-6 and Syndiniales Group II) at 13 first-year sea-ice stations localized in Barrow Strait and in the vicinity of Cornwallis Island, Canadian Arctic Archipelago. We applied Catalyzed Reporter Deposition–Fluorescence In Situ Hybridization to identify selected groups at a single cell level. Pavlovaphyceae and stramenopiles from groups MAST-2 and MAST-6 were for the first time reported from sea ice. Total numbers of picoeukaryotes were significantly higher in the vicinity of Cornwallis Island than in Barrow Strait. Similar trend was observed for all the groups except for haptophytes. Chlorophytes and cryptophytes were the dominant plastidic, and MAST-2 most numerous aplastidic of all the groups investigated. Numbers of total picoeukaryotes, chlorophytes and MAST-2 stramenopiles were positively correlated with the thickness of snow cover. All studied algal and MAST groups fed on bacteria. Presence of picoeukaryotes from various trophic groups (mixotrophs, phagotrophic and parasitic heterotrophs) indicates the diverse ecological roles picoeukaryotes have in sea ice. Yet, &gt;50% of total sea-ice picoeukaryote cells remained unidentified, highlighting the need for further study of functional and phylogenetic sea-ice diversity, to elucidate the risks posed by ongoing Arctic changes.
Diverse populations of lake water bacteria exhibit chemotaxis towards inorganic nutrients
Authors: Dennis Paul G , Seymour Justin , Kumbun Kimber , Tyson Gene W 
Published: March 2013

Abstract
Chemotaxis allows microorganisms to rapidly respond to different environmental stimuli; however, understanding of this process is limited by conventional assays, which typically focus on the response of single axenic cultures to given compounds. In this study, we used a modified capillary assay coupled with flow cytometry and 16S rRNA gene amplicon pyrosequencing to enumerate and identify populations within a lake water microbial community that exhibited chemotaxis towards ammonium, nitrate and phosphate. All compounds elicited chemotactic responses from populations within the lake water, with members of Sphingobacteriales exhibiting the strongest responses to nitrate and phosphate, and representatives of the Variovorax, Actinobacteria ACK-M1 and Methylophilaceae exhibiting the strongest responses to ammonium. Our results suggest that chemotaxis towards inorganic substrates may influence the rates of biogeochemical processes.
Effect of DNA conformation on facilitated diffusion
Authors: Brackley Chris A. , Cates Mike E. , Marenduzzo Davide 
Published: March 2013

Within a living cell, site-specific DNA-binding proteins need to search the whole genome to find a target of ~10–20 bp. That they find the target, and do so quickly, is vital for the correct functioning of the DNA, and of the cell as a whole. The current understanding is that this search is performed via facilitated diffusion, i.e. by combining three-dimensional bulk diffusion within the cytoplasm or nucleoplasm, with one-dimensional diffusion along the DNA backbone, to which the protein binds non-specifically. After reviewing the standard theory of facilitated diffusion, we discuss in the present article the still rather rare direct computer simulations of this process, focusing on the three-dimensional part of the search, and the effect of DNA looping and the general DNA conformation on its efficiency. We close by highlighting some open questions in this field.
Studies of bacterial topoisomerases I and III at the single-molecule level
Authors: Terekhova Ksenia , Marko John F. , Mondragón Alfonso 
Published: March 2013

Topoisomerases are the enzymes responsible for maintaining the supercoiled state of DNA in the cell and also for many other DNA-topology-associated reactions. Type IA enzymes alter DNA topology by breaking one DNA strand and passing another strand or strands through the break. Although all type IA topoisomerases are related at the sequence, structure and mechanism levels, different type IA enzymes do not participate in the same cellular processes. We have studied the mechanism of DNA relaxation by Escherichia coli topoisomerases I and III using single-molecule techniques to understand their dissimilarities. Our experiments show important differences at the single-molecule level, while also recovering the results from bulk experiments. Overall, topoisomerase III relaxes DNA using fast processive runs followed by long pauses, whereas topoisomerase I relaxes DNA through slow processive runs followed by short pauses. These two properties combined give rise to the overall relaxation rate, which is higher for topoisomerase I than for topoisomerase III, as expected from many biochemical observations. The results help us to understand better the role of these two topoisomerases in the cell and also serve to illustrate the power of single-molecule experiments to uncover new functional characteristics of biological molecules.
3–10 GHz self‐biased resistive‐feedback LNA with inductive source degeneration
Authors: Feng C. , Yu X. P. , Lu Z. H. , Lim W. M. , Sui W. Q. 
Published: March 2013

A 3–10 GHz self‐biased low‐noise amplifier (LNA) implemented in Global Foundries 65 nm CMOS process is presented. A novel input‐matching network employing the resistive feedback and inductive source degeneration techniques is proposed to achieve the wideband matching as well as low noise figure. The LNA exhibits a power gain of 17 ± 1 dB over 3–10 GHz with noise figure ranging from 3.5 to 4.3 dB. The fabricated LNA occupies an area of 0.15 mm2 and draws 12 mA from 1.2 V power supply.
Surface electrode configurations for quartz MEMS double‐ended tuning fork resonator
Authors: Liang Jinxing , Chai Yanli , Meng Guangchan , Chen Xueying 
Published: March 2013

The quartz double‐ended tuning fork (DETF) resonator is well known to be sensitive to longitudinal force and is widely used as the sensing element in modern accelerometer, force and pressure sensors. The quartz DETF resonator works in‐plane, with anti‐phase flexural mode vibration, which is driven into oscillation by internal strains created by AC voltages applied to electrode patterns on the beams. The DETF vibration modes and vibration characteristics are determined by the electrode pattern and its electromechanical coupling efficiency. Presented are three kinds of electrode patterns for different applications, and the effect of electrode patterns on the vibration performances are investigated experimentally. With the fundamental frequency at 65 KHz, the DETF resonator is designed and fabricated using the wet etching‐based quartz MEMS technique. The vibration characteristics including Q‐ value, and equivalent parameters, are evaluated using a 4294 A impedance analyser. Experimental results demonstrated that the vibration characteristics of quartz DETFs are affected by the electrode patterns including pattern location and widths. These results are expected to be useful for designing quartz DETF based devices.
Comparative study on the freezing temperature synthesised CdSe nanoparticles before and after annealing
Authors: Sinha Subhojyoti , Chatterjee Sanat Kumar , Ghosh Jiten , Meikap Ajit Kumar 
Published: March 2013

Thiyoglycolic acid‐capped CdSe nanoparticles have been synthesised at 273–279 K. A comparative study on the structural and optical characteristics of the as‐synthesised and annealed samples is done using state‐of‐the art instruments and software. Based on these studies here the authors report a colossal change in crystallinity, particle size and red shift in the absorption spectra upon annealing. Lattice strain is also found to increase by 18.77% upon annealing. Excitation wavelength‐dependent photoluminescence with giant Stokes shift and narrow full‐width at half‐maxima of both the samples is also reported, which may be useful for device application.
Simple process for 60 nm patterned nickel stamp replication
Authors: Zhang Ran , Chu Jinkui , Min Jian , Wang Haixiang , Wang Zhiwen 
Published: March 2013

A simple process for nickel nanoimprint stamp replication is proposed. Based on this process, the replication of a 15 × 20 mm nickel nanoimprint stamp with 60 nm grating structures was carried out. First, the nanograting structures on the master silicon stamp were transferred to a polymer substrate using the hot embossing process; then, a layer of nickel was sputtered to fill the nanostructures on the substrate surface and form the seed layer for the electroforming process; finally, the back plane of the replica is electroformed. The observation results show good correlation between the dimensions of the master stamp's features and the corresponding replicated features. The performance test result of the replicated stamp demonstrated that the mechanical strength of the replica is sufficient for the hot embossing process.
Performance analysis of single‐walled carbon nanotube bundle interconnects for three‐dimensional integration applications
Authors: Qian Libo , Zhu Zhangming , Ding Ruixue , Yang Yintang 
Published: March 2013

Compact equivalent circuit models for single‐walled carbon nanotube (SWCNT) bundles are described, and the performance of SWCNT bundle interconnects is evaluated and compared with traditional Cu interconnects at different interconnect levels for through‐silicon‐via‐based three‐dimensional integration. It is shown that at local level, carbon nanotube bundle interconnects exhibit lower signal delay and smaller optimal wire size. At intermediate and global levels, delay improvement becomes more significant with technology scaling and increasing wire lengths. For 1 mm intermediate and 10 mm global level interconnects, the delay of SWCNT bundles can reach 45.49 and 51.84% of that of Cu wires, respectively.
Characterising Vulnerability to Poverty in Rural Haiti: A Multilevel Decomposition Approach
Authors: Échevin Damien 
Published: March 2013

AbstractThis article characterises vulnerability to poverty in Haiti using a unique survey conducted in 2007 in rural areas. In a first step, using two‐level linear random coefficient models of both per capita consumption and per capita income, the article assesses the impact of self‐reported shocks on households' economic well‐being. In a second step, the prediction model is used to calculate various measures of vulnerability to poverty, considering various types of shocks. Empirical findings show that self‐reported (or observable) idiosyncratic shocks, in particular health‐related shocks, have larger impact on vulnerability to poverty than observable covariate shocks. These results are in line with the fact that many households reported idiosyncratic health shocks as being the worst shocks they experienced. On the other hand, unobservable idiosyncratic shocks appear to have generally more influence on households' vulnerability to poverty than unobservable covariate ones. We also show that omitting self‐reported shocks in the analysis leads to an underestimate of households' vulnerability to poverty.