87 research outputs found
Constraint Reasoning and Kernel Clustering for Pattern Decomposition with Scaling
Abstract. Motivated by an important and challenging task encountered in material discovery, we consider the problem of finding K basis patterns of numbers that jointly compose N observed patterns while enforcing additional spatial and scaling constraints. We propose a Constraint Pro-gramming (CP) model which captures the exact problem structure yet fails to scale in the presence of noisy data about the patterns. We allevi-ate this issue by employing Machine Learning (ML) techniques, namely kernel methods and clustering, to decompose the problem into smaller ones based on a global data-driven view, and then stitch the partial solu-tions together using a global CP model. Combining the complementary strengths of CP and ML techniques yields a more accurate and scalable method than the few found in the literature for this complex problem.
Little Technicolor
Inspired by the AdS/CFT correspondence, we show that any G/H symmetry
breaking pattern can be described by a simple two-site moose diagram. This
construction trivially reproduces the CCWZ prescription in the context of
Hidden Local Symmetry. We interpret this moose in a novel way to show that many
little Higgs theories can emerge from ordinary chiral symmetry breaking in
scaled-up QCD. We apply this reasoning to the simple group little Higgs to see
that the same low energy degrees of freedom can arise from a variety of UV
complete theories. We also show how models of holographic composite Higgs
bosons can turn into brane-localized little technicolor theories by
"integrating in" the IR brane.Comment: 26 pages, 2 figures; v2: references added; v3: added section on
vacuum alignment to match JHEP versio
The Littlest Higgs in Anti-de Sitter Space
We implement the SU(5)/SO(5) littlest Higgs theory in a slice of 5D Anti-de
Sitter space bounded by a UV brane and an IR brane. In this model, there is a
bulk SU(5) gauge symmetry that is broken to SO(5) on the IR brane, and the
Higgs boson is contained in the Goldstones from this breaking. All of the
interactions on the IR brane preserve the global symmetries that protect the
Higgs mass, but a radiative potential is generated through loops that stretch
to the UV brane where there are explicit SU(5) violating boundary conditions.
Like the original littlest Higgs, this model exhibits collective breaking in
that two interactions must be turned on in order to generate a Higgs potential.
In AdS space, however, collective breaking does not appear in coupling
constants directly but rather in the choice of UV brane boundary conditions. We
match this AdS construction to the known low energy structure of the littlest
Higgs and comment on some of the tensions inherent in the AdS construction. We
calculate the 5D Coleman-Weinberg effective potential for the Higgs and find
that collective breaking is manifest. In a simplified model with only the SU(2)
gauge structure and the top quark, the physical Higgs mass can be of order 200
GeV with no considerable fine tuning (25%). We sketch a more realistic model
involving the entire gauge and fermion structure that also implements T-parity,
and we comment on the tension between T-parity and flavor structure.Comment: 42 pages, 7 figures, 3 tables; v2: minor rewording, JHEP format; v3:
to match JHEP versio
Dynamics of Warped Flux Compactifications
We discuss the four dimensional effective action for type IIB flux
compactifications, and obtain the quadratic terms taking warp effects into
account. The analysis includes both the 4-d zero modes and their KK
excitations, which become light at large warping. We identify an `axial' type
gauge for the supergravity fluctuations, which makes the four dimensional
degrees of freedom manifest. The other key ingredient is the existence of
constraints coming from the ten dimensional equations of motion. Applying these
conditions leads to considerable simplifications, enabling us to obtain the low
energy lagrangian explicitly. In particular, the warped K\"ahler potential for
metric moduli is computed and it is shown that there are no mixings with the KK
fluctuations and the result differs from previous proposals. The four
dimensional potential contains a generalization of the Gukov-Vafa-Witten term,
plus usual mass terms for KK modes.Comment: 37 pages. v2. References added, typos corrected. v3. Matches JHEP
versio
Influence of Dietary Oil Content and Conjugated Linoleic Acid (CLA) on Lipid Metabolism Enzyme Activities and Gene Expression in Tissues of Atlantic Salmon (Salmo salar L.)
The overall objective is to test the hypothesis that conjugated linoleic acid (CLA) has beneficial effects in Atlantic salmon through affecting lipid and fatty acid metabolism. The specific aims of the present study were to determine the effects of CLA on some key pathways of fatty acid metabolism including fatty acid oxidation and highly unsaturated fatty acid (HUFA) synthesis. Salmon smolts were fed diets containing two levels of fish oil (low, ~18% and high, ~34%) containing three levels of CLA (a 1:1 mixture of 9-cis,trans-11 and trans-10,cis-12 at 0, 1 and 2% of diet) for 3 months. The effects of dietary CLA on HUFA synthesis and β-oxidation were measured and the expression of key genes in the fatty acid oxidation and HUFA synthesis pathways, and potentially important transcription factors, peroxisome proliferators activated receptors (PPARs), determined in selected tissues. Liver HUFA synthesis and desaturase gene expression was increased by dietary CLA and decreased by high dietary oil content. Carnitine palmitoyltransferase-I (CPT-I) activity and gene expression were generally increased by CLA in muscle tissues although dietary oil content had relatively little effect. In general CPT-I activity or gene expression was not correlated with β-oxidation. Dietary CLA tended to increase PPARι and β gene expression in both liver and muscle tissues, and PPARγ in liver. In summary, gene expression and activity of the fatty acid pathways were altered in response to dietary CLA and/or oil content, with data suggesting that PPARs are also regulated in response to CLA. Correlations were observed between dietary CLA, liver HUFA synthesis and desaturase gene expression, and liver PPARι expression, and also between dietary CLA, CPT-I expression and activity, and PPARι expression in muscle tissues. In conclusion, this study suggests that dietary CLA has effects on fatty acid metabolism in Atlantic salmon and on PPAR transcription factors. However, further work is required to assess the potential of CLA as a dietary supplement, and the role of PPARs in the regulation of lipid metabolism in fish
Physical forcing and physical/biochemical variability of the Mediterranean Sea: a review of unresolved issues and directions for future research
This paper is the outcome of a workshop held in Rome in November 2011 on the occasion of the 25th anniversary of the POEM (Physical Oceanography of the Eastern Mediterranean) program. In the workshop discussions, a number of unresolved issues were identified for the physical and biogeochemical properties of the Mediterranean Sea as a whole, i.e., comprising the Western and Eastern sub-basins. Over the successive two years, the related ideas were discussed among the group of scientists who participated in the workshop and who have contributed to the writing of this paper.
Three major topics were identified, each of them being the object of a section divided into a number of different sub-sections, each addressing a specific physical, chemical or biological issue:
1. Assessment of basin-wide physical/biochemical properties, of their variability and interactions.
2. Relative importance of external forcing functions (wind stress, heat/moisture fluxes, forcing through straits) vs. internal variability.
3. Shelf/deep sea interactions and exchanges of physical/biogeochemical properties and how they affect the sub-basin circulation and property distribution.
Furthermore, a number of unresolved scientific/methodological issues were also identified and are reported in each sub-section after a short discussion of the present knowledge. They represent the collegial consensus of the scientists contributing to the paper. Naturally, the unresolved issues presented here constitute the choice of the authors and therefore they may not be exhaustive and/or complete. The overall goal is to stimulate a broader interdisciplinary discussion among the scientists of the Mediterranean oceanographic community, leading to enhanced collaborative efforts and exciting future discoveries
Connecting the data landscape of long-term ecological studies: The SPI-Birds data hub
The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-term studies of birds, we have created the SPI-Birds Network and Database (www.spibirds.org)\u2014a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI-Birds has recruited over 120 members, and currently hosts data on almost 1.5 million individual birds collected in 80 populations over 2,000 cumulative years, and counting. SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by the principles of Findable, Accessible, Interoperable and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language). The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such as ours, COMADRE for animal demography, etc.) will aid much-needed large-scale ecological data integration
A multiâomics approach identifies key regulatory pathways induced by longâterm zinc supplementation in human primary retinal pigment epithelium
In age-related macular degeneration (AMD), both systemic and local zinc levels decline.
Elevation of zinc in clinical studies delayed the progression to end-stage AMD. However, the molecular
pathways underpinning this beneficial effect are not yet identified. In this study, we used differentiated
primary human fetal retinal pigment epithelium (RPE) cultures and long-term zinc supplementation
to carry out a combined transcriptome, proteome and secretome analysis from three genetically
different human donors. After combining significant differences, we identified the complex molecular
networks using Database for Annotation, Visualization and Integrated Discovery (DAVID) and
Ingenuity Pathway Analysis (IPA). The cell cultures from the three donors showed extensive
pigmentation, development of microvilli and basal infoldings and responded to zinc supplementation
with an increase in transepithelial electrical resistance (TEER) (apical supplementation: 443.2 Âą 79.3%,
basal supplementation: 424.9 Âą 116.8%, compared to control: 317.5 Âą 98.2%). Significant changes were
observed in the expression of 1044 genes, 151 cellular proteins and 124 secreted proteins. Gene set
enrichment analysis revealed changes in specific molecular pathways related to cell adhesion/polarity,
extracellular matrix organization, protein processing/transport, and oxidative stress response by zinc
and identified a key upstream regulator effect similar to that of TGFB1
Search for supersymmetry in events with photons and low missing transverse energy in pp collisions at âs=7 TeV
This is the pre-print version of the Article. The official published version can be accessed from the links below - Copyright @ 2013 Elsevier.Many models of new physics, including versions of supersymmetry (SUSY), predict production of events with low missing transverse energy, electroweak gauge bosons, and many energetic final-state particles. The stealth SUSY model yields this signature while conserving R-parity by means of a new hidden sector in which SUSY is approximately conserved. The results of a general search for new physics, with no requirement on missing transverse energy, in events with two photons and four or more hadronic jets are reported. The study is based on a sample of protonâproton collisions at âs=7 TeV corresponding to 4.96 fbâ1 of integrated luminosity collected with the CMS detector in 2011. Based on good agreement between the data and the standard model expectation, the data are used to determine model-independent cross-section limits and a limit on the squark mass in the framework of stealth SUSY. With this first study of its kind, squark masses less than 1430 GeV are excluded at the 95% confidence level.This study is supported by the BMWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); MEYS (Czech Republic); MoER, SF0690030s09 and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MSI (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MON, RosAtom, RAS and RFBR (Russia); MSTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); ThEP, IPST and NECTEC (Thailand); TUBITAK and TAEK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA)
Transverse-momentum and pseudorapidity distributions of charged hadrons in pp collisions at âs=0.9 and 2.36 TeV
Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at root s = 0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0.46 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 0.9 TeV and 0.50 +/- 0.01 (stat.) +/- 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between -2.4 and +2.4. At these energies, the measured pseudorapidity densities in the central region, dN(ch)/d eta vertical bar(vertical bar eta vertical bar and pp collisions. The results at 2.36 TeV represent the highest-energy measurements at a particle collider to date
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