cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Can Eliminating School Fees in Poor Districts Boost Enrollment?
Creators: name: Borkum, Evan
Publisher: name: Columbia University
Year: 2009
Subjects: Economics

description: The charging of school user fees is a much-debated policy issue in developing countries. In this paper, I evaluate the impact of a South African fee elimination program that was targeted at the poorest two quintiles of schools based on a community poverty score. Fixed effects estimates find that the program increased enrollment by almost 2% in treated secondary schools, an increase concentrated in earlier secondary grades. There is substantial heterogeneity in the estimated secondary school effect: it is driven entirely by an increase of around 3.5% in the poorer of the two treated quintiles. Regression discontinuity estimates confirm that the relatively wealthy schools near the treatment cutoff did not experience any effects on enrollment. Overall, the abolition of fees seems to have been reasonably effective in increasing secondary school enrollment in particularly poor communities. This is despite the fact that the eliminated fees were relatively low, comprising only around 1.5% of annual household income (per child) in these communities.
Gravity and Large-Scale Non-local Bias
Creators: name: Chan, Kwan Chuen
name: Scoccimarro, Roman
name: Sheth, Ravi K.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The relationship between galaxy and matter overdensities, bias, is most often assumed to be local. This is however unstable under time evolution, we provide proofs under several sets of assumptions. In the simplest model galaxies are created locally and linearly biased at a single time, and subsequently move with the matter (no velocity bias) conserving their comoving number density (no merging). We show that, after this formation time, the bias becomes unavoidably non-local and non-linear at large scales. We identify the non-local gravitationally induced fields in which the galaxy overdensity can be expanded, showing that they can be constructed out of the invariants of the deformation tensor (Galileons). In addition, we show that this result persists if we include an arbitrary evolution of the comoving number density of tracers. We then include velocity bias, and show that new contributions appear, a dipole field being the signature at second order. We test these predictions by studying the dependence of halo overdensities in cells of fixed matter density: measurements in simulations show that departures from the mean bias relation are strongly correlated with the non-local gravitationally induced fields identified by our formalism. The effects on non-local bias seen in the simulations are most important for the most biased halos, as expected from our predictions. The non-locality seen in the simulations is not fully captured by assuming local bias in Lagrangian space. Accounting for these effects when modeling galaxy bias is essential for correctly describing the dependence on triangle shape of the galaxy bispectrum, and hence constraining cosmological parameters and primordial non-Gaussianity. We show that using our formalism we remove an important systematic in the determination of bias parameters from the galaxy bispectrum, particularly for luminous galaxies. (abridged)
description: 26 pages, 9 figures. v2: improved appendix A
Room assignment-rent division: A market approach
Creators: name: Abdulkadiroglu, Atila
name: Sonmez, Tayfun
name: Unver, M. Utku
Publisher: name: Columbia University
Year: 2002
Subjects: Economics

description: A group of friends consider renting a house but they shall first agree on how to allocate its rooms and share the rent. We propose an auction mechanism for room assignment-rent division problems which mimics the market mechanism. Our auction mechanism is efficient, envy-free, individually-rational and it yields a non-negative price to each room whenever that is possible with envy-freeness.
mSLP: Mesh-enhanced Service Location Protocol
Creators: name: Zhao, Weibin
name: Schulzrinne, Henning G.
Publisher: name: Columbia University
Year: 2000
Subjects: Computer science

description: The Service Location Protocol (SLP) is a proposed standard from IETF. It provides a flexible and scalable service discovery framework in IP network, and it can work with or without a directory service. This paper presents mSLP - Mesh-enhanced Service Location Protocol. mSLP proposes to use a fully meshed peering Directory Agent (DA) architecture. Peer DAs exchange service registration information, and keep the same consistent data for the shared scopes. mSLP provides a reliable directory service for an SLP system. It also greatly simplifies SLP service registration leading to a thin-client Service Agent (SA) implementation. mSLP is backward compatible with SLPv2, and incremental deployment is supported.
Turnover reflects specific training better than wages do
Creators: name: Munasinghe, Lalith
name: O'Flaherty, Brendan Andrew
Publisher: name: Columbia University
Year: 2002
Subjects: Economics
Labor economics
Labor turnover

description: Turnover falls with tenure - this is one of the best established empirical regularities of labor economics - but finding a tenure effect on wages seems to be very hard. Within-job wage cuts do not seem very uncommon either. We reconcile these findings by revisiting an old question: how gains from firm specific training are split between workers and firms. The division is determined by a stationary distribution of outside offers. The model is ex post monopsony: the lower a wage a firm pays to a specifically trained worker, the more profit it makes and the more eager it is to have her stay, but the more likely she is to leave. The optimal time paths of wages and turnover probabilities show that even if marginal product is increasing, wages need not be increasing; but rising marginal product always implies a falling turnover rate.
The hot-Jupiter Kepler-17b: discovery, obliquity from stroboscopic starspots, and atmospheric characterization
Creators: name: Désert, Jean-Michel
name: Charbonneau, David
name: Demory, Brice-Olivier
name: Ballard, Sarah
name: Carter, Joshua A.
name: Fortney, Jonathan J.
name: Cochran, William D.
name: Endl, Michael
name: Quinn, Samuel N.
name: Isaacson, Howard T.
name: Fressin, Francois
name: Buchhave, Lars A.
name: Latham, David W.
name: Knutson, Heather A.
name: Bryson, Stephen T.
name: Torres, Guillermo
name: Rowe, Jason F.
name: Batalha, Natalie M.
name: Borucki, William J.
name: Brown, Timothy M.
name: Caldwell, Douglas A.
name: Christiansen, Jessie L.
name: Deming, Drake
name: Fabrycky, Daniel C.
name: Ford, Eric B.
name: Gilliland, Ronald L.
name: Gillon, Michaël
name: Haas, Michaël R.
name: Jenkins, Jon M.
name: Kinemuchi, Karen
name: Koch, David
name: Lissauer, Jack J.
name: Mullally, Fergal
name: MacQueen, Phillip J.
name: Marcy, Geoffrey W.
name: Sasselov, Dimitar D.
name: Seager, Sara
name: Still, Martin
name: Tenenbaum, Peter
name: Uddin, Kamal
name: Winn, Joshua N.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: This paper reports the discovery and characterization of the transiting hot giant exoplanet Kepler-17b. The planet has an orbital period of 1.486 days, and radial velocity measurements from the Hobby-Eberly Telescope (HET) show a Doppler signal of 420+/-15 m.s-1. From a transit-based estimate of the host star's mean density, combined with an estimate of the stellar effective temperature T_eff=5630+/-100 K from high-resolution spectra, we infer a stellar host mass of 1.061+/-0.067 M_sun and a stellar radius of 1.019+/-0.033 R_jup. We estimate the planet mass and radius to be Mp=2.450+/-0.114 M_jup and Rp=1.312+/-0.018 R_jup and a planet density near 1.35 g.cm-3. The host star is active, with dark spots that are frequently occulted by the planet. The continuous monitoring of the star reveals a stellar rotation period of 11.89 days, 8 times the the planet's orbital period; this period ratio produces stroboscopic effects on the occulted starspots. The temporal pattern of these spot-crossing events shows that the planet's orbit is prograde and the star's obliquity is smaller than 15 deg. We detected planetary occultations of Kepler-17b with both the Kepler and Spitzer Space Telescopes. We use these observations to constrain the eccentricity, e, and find that it is consistent with a circular orbit (e<0.0011). The brightness temperatures of the planet the infrared bandpasses are T_3.6um=1880+/-100 K and T4.5um=1770+/-150 K. We measure the optical geometric albedo A_g in the Kepler bandpass and find A_g = 0.10+/-0.02. The observations are best described by atmospheric models for which most of the incident energy is re-radiated away from the day side.
description: 21 pages, 13 figures, Accepted for publication in ApJ on October 14, 2011
Information and Export Decisions: Bank’s Role as a Conduit of Information
Creators: name: Inui, Tomohiko
name: Ito, Keiko
name: Miyakawa, Daisuke
name: Shoji, Keishi
Publisher: name: Columbia University
Year: 2013
Subjects: Commerce
Asians
Management

description: This paper examines how firms’ decision to start exporting is affected by the availability of information on export markets. Unlike existing studies which focus on information sharing among firms, we are interested in the information provided by firms’ main bank. Specifically, using a unique dataset containing information on both Japanese firms’ export activities and their main banks’ experience in transacting with other exporting firms, we examine whether main banks act as a conduit of information on export markets. We find that information spillovers through main banks positively affect client firms’ decision to start exporting (extensive margin), implying that information on foreign markets provided by banks substantially reduces the fixed entry cost of exporting. On the other hand, we do not find any evidence that information provided by banks has an effect on the export volume or on the growth rate of exports (intensive margin). Our results highlight that channels of information spillovers other than those examined in the literature so far may be of considerable importance.
Dendrocoris fruticicola
Creators: name: Thomas, D. B. Jr.
name: H. Brailovsky
Publisher: name: Zenodo
Year: 1999
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Pentatomidae
Dendrocoris
Dendrocoris fruticicola

description: Dendrocoris fruticicola (Bergroth 1891)
(Figure 9)
Diagnosis. Vertex of head flat. Juga contiguous before tylus. Cicatrices concolorous with pronotal disk. Anterolateral pronotal margins weakly concave in dorsal view. Huineral angles prominent but not produced. Tubercle present at base of abdomen in both sexes. Abdominal spiracles ringed in black. Veins of hemelytral membrane not reticulate. Apex of male paramere with a long tapering digit and a shorter truncate digit (Fig. 9). Mesial emargination of pygophore not attended by small, black, teeth.
Distribution. USA: Alabama, Georgia, Florida, Mississippi, North Carolina, Virginia.
Remarks. Within its range in the southeastern U.S. it is the only species with darkly ringed spiracles. Hoffman (1971) cites collectionrecords on oak. Nelson (1955) reports it on pine.
description: Published as part of Thomas, D. B. Jr. & H. Brailovsky, 1999, Review of the genus Dendrocoris Bergroth with descriptions of new species (Pentatomidae: Heteroptera), pp. 1-9 in Insecta Mundi 13 on pages 6-7
Warm Gas in the Virgo Cluster: I. Distribution of Lya Absorbers
Creators: name: Yoon, Joo Heon
name: Putman, Mary
name: Thom, Christopher
name: Chen, Hsiao-Wen
name: Bryan, Greg
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The first systematic study of the warm gas (T=10^4-5 K) distribution across a galaxy cluster is presented using multiple background QSOs to the Virgo Cluster. We detect 25 Lya absorbers (N_HI = 10^13.1-15.4 cm^-2) in the Virgo velocity range toward 9 of 12 QSO sightlines observed with Cosmic Origin Spectrograph, with a cluster impact parameter range of 0.36-1.65 Mpc (0.23-1.05R_vir). Including 18 Lya absorbers previously detected by STIS or GHRS toward 7 of 11 background QSOs in and around the Virgo Cluster, we establish a sample of 43 absorbers towards a total of 23 background probes for studying the incidence of Lya absorbers in and around the Virgo Cluster. With these absorbers, we find: (1) warm gas is predominantly in the outskirts of the cluster and avoids the X-ray detected hot ICM. Also, Lya absorption strength increases with cluster impact parameter. (2) Lya absorbing warm gas traces cold HI emitting gas in the substructures of the Virgo Cluster. (3) Including the absorbers associated with the surrounding substructures, the warm gas covering fraction (100% for N_HI > 10^13.1 cm^-2) is in agreement with cosmological simulations. We speculate that the observed warm gas is part of large-scale gas flows feeding the cluster both the ICM and galaxies.
description: 15 pages, 6 figures, 8 tables, ApJ in press
A Flexible and Efficient Protocol for Multi-Scope Service Registry Replication
Creators: name: Zhao, Weibin
name: Schulzrinne, Henning G.
Publisher: name: Columbia University
Year: 2002
Subjects: Computer science

description: Service registries play an important role in service discovery systems by accepting service registrations and answering service queries; they can serve a wide range of purposes, such as membership services, lookup services, and search services. To provide fault tolerant, and enhance scalability, availability and performance, service registries often need to be replicated. In this paper, we present Swift (Selective anti-entropy WIth FasT update propagation), a flexible and efficient protocol for multi-scope service registry replication. As consistency is a less of concern compared with availability in service registry replication, we choose to build Swift on top of anti-entropy to support high availability replication. Swift makes two contributions as follows. First, it defines a more general and flexible form of anti-entropy called selective anti-entropy, which extends the applicability of anti-entropy from full replication to partial replication by selectively reconciling inconsistent states between two replicas, and improves anti-entropy efficiency by fine controlling update propagation within each subset. Selective anti-entropy is the first that we are aware of in using anti-entropy to support generic partial replication. Secondly, Swift integrates service registry overlay networks with selective anti-entropy. Different topologies, such as full mesh and spanning tree, can be used for constructing service registry overlay networks. These overlay networks are used to propagate new updates quickly so as to minimize inconsistency among replicas. We have implemented Swift for replicating multi-scope Directory Agents in the Service Location Protocol. Our experience shows that Swift is flexible, efficient, and lightweight.
The Classical Origins of Akamatsu’s “Flying-Geese” Theory: A Note on a Missing Link to David Hume
Creators: name: Ozawa, Terutomo
Publisher: name: Columbia University
Year: 2013
Subjects: Economics
Asians

description: The ‘flying-geese” theory of economic development introduced by Kaname Akamatsu (1897-1974) of Hitotsubashi University in the mid-1930s is the only “Japan-born” theory that has so far attracted wide attention and some acceptability in the academia worldwide. Studying in Germany for two years in 1924-26, Akamatsu was strongly influenced by a number of development-stages theories expounded by the German historical school, notably Friedrich List (1789-1846), Bruno Hildebrand (1812-1878), Karl Marx (1818-1883), and Gustav von Schmoller (1838-1917). Akamatsu also drew on the ideas of Alexander Hamilton (1757-1804) and Henry Carey (1793-1879), both Americans, who along with List, advocated infant-industry protection in order to build national industrial development. Surprising is, however, that there is no mention of David Hume (1711-1776) in Akamastsu’s works despite the fact that Hume was a noted thinker on economic development and a major philosopher, who impacted both Immanuel Kant (1724-1804) and Georg Wilhelm F. Hegel (1770-1831). Akamatsu was very much engrossed in Hegelian dialectic. His analysis was, in fact, couched in dialectical perspectives. What is most fascinating was that Hume (1754) observed how a rich country is destined to lose its competitiveness in manufacturing and compels its producersto “gradually shift their places, leaving those countries and provinces which they have already enriched, and flying to others, whither they are allured by the cheapness of provisions and labour” (emphasis added). Hume thus zeroed in on the core mechanism of cross-border industrial transmigration and a sequential spread of economic growth and prosperity from one emerging economy to another. His insightful observation amply adumbrated Akamatsu’s flying-geese theory, though the latter apparently missed to notice it.
Wess-Zumino Consistency Condition for Entanglement Entropy
Creators: name: Banerjee, Shamik
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this brief note, we consider the variation of the entanglement entropy of a region as the shape of the entangling surface is changed. We show that the variation satisfies a Wess-Zumino like integrability condition in field theories which can be consistently coupled to gravity. In this case the "anomaly" is localized on the entangling surface. The solution of the integrability condition should give all the nontrivial finite local terms which can appear in the variation of the entanglement entropy.
description: 14 pages, presentation improved
MELD: A Multi-Paradigm Language with Objects, Dataflow and Modules
Creators: name: Kaiser, Gail E.
name: Garlan, David
Publisher: name: Columbia University
Year: 1987
Subjects: Computer science

description: This technical report consists of the two most recent papers from the MELD project. Melding Software Systems from Reusable Building Blocks describes MELD as a declarative language that combines facilities from the package library, software generation and object-oriented language approaches to reusability. MEWing Data Flow and Object-Oriented Programming emphasizes the multi-paradigm nature of MELD and introduces overriding of inherited facilities and generic features, and discusses compile-time error detection.
Home production, market production and the gender wage gap: Incentives and expectations
Creators: name: Albanesi, Stefania
name: Olivetti, Claudia
Publisher: name: Columbia University
Year: 2007
Subjects: Labor economics
Gender identity
Sex role

description: The purpose of this paper is to study the joint determination of gender differentials in labor market outcomes and in the household division of labor. Specifically, we explore the hypothesis that incentive problems in the labor market amplify differences in earnings due to gender differentials in home hours. In turn, earnings differentials reinforce the division of labor within the household, leading to a potentially self-fulfilling feedback mechanism. The workings of the labor market are key in our story. The main assumptions are that the utility cost of work effort is increasing in home hours, and that higher effort should correspond to higher incentive pay. Household decisions are Pareto efficient, leading to a negative correlation between relative home hours and earnings across spouses. We use the Census and the PSID to study these predictions and find that they are supported by the data.
Intertemporal distortions in the second best
Creators: name: Albanesi, Stefania
name: Armenter, Roc
Publisher: name: Columbia University
Year: 2007
Subjects: Economics
Finance

description: We consider a very general class of public finance problems that encompasses Ramsey models of optimal taxation as well as economies with limited commitment, private information, and political economy frictions. We identify a sufficient condition to rule out permanent intertemporal distortions at the optimum: If there exists an admissible allocation that converges to the first best steady state, then all intertemporal distortions are temporary in the second best. We analyze a series of applications to illustrate the significance of this result.
Nature or Nurture? Factors of Entrepreneurship: a Comparative Approach
Creators: name: Tortella, Gabriel
name: Quiroga, Gloria
name: Moral-Arce, Ignacio
Publisher: name: Columbia University
Year: 2009
Subjects: Entrepreneurship
Business
Education
Entrepreneurship--Study and teaching

description: There is an ongoing discussion about whether entrepreneurship is basically an innate gift or whether education has a traceable effect on the quality and success of entrepreneurs. This paper tries to put these hypotheses to test by means of a comparison of English and Spanish businessmen. Based on a large database, and using descriptive analysis and econometric tests it shows that although the educational systems in both countries are quite different, entrepreneurs respond to the quantity and quality of education they have received.
Long-Term Earnings Losses Due to Job Separation During the 1982 Recession
Creators: name: Wachter, Till Von
name: Song, Jae
name: Manchester, Joyce
Publisher: name: Columbia University
Year: 2007
Subjects: Labor economics
Commerce

description: We present new estimates of the long-run earnings consequences of job separations that occurred during the 1982 recession based on a representative sample of workers drawn from Social Security administrative earnings data ranging from 1974 to 2005. Workers permanently leaving their long-term employer in the period from 1980 to 1985 experienced large and persistent earnings reductions lasting 15 to 20 years compared to workers of similar age and earnings potential who did not leave their employer. Earnings losses last up to 15 years even for workers displaced in better economic times or after shorter job tenure. These losses arise both due to reductions in employment as well as to reductions in annual earnings for those working. These preliminary estimates appear to confirm results from single U.S. states or limited time periods suggesting that job loss can be very costly for affected workers.
Load transfer characteristics between posterior fusion devices and the lumbar spine under shear loading : an in vitro investigation
Creators: name: Melnyk, Angela Dorothy
Publisher: name: University of British Columbia
Year: 2011

description: Introduction: Clinical studies have demonstrated beneficial results of posterior arthrodesis for the treatment of degenerative spondylolisthesis (DS). The optimal stiffness of these fusion systems to enhance load-sharing and fusion rate while minimizing adjacent segment stresses is unknown. To our knowledge, posterior instrumentation for DS has not been tested under anterior shear loads, a highly relevant loading direction for DS. Objectives: To determine the amount of shear load supported by posterior lumbar fusion devices of varying stiffness under shear loading. Methods: The effect of implant stiffness and specimen condition on implant load was assessed in a biomechanical study. Fifteen human cadaveric lumbar functional spinal units were tested under a static 300 N axial compression load and a cyclic anterior shear load (5-250 N). Implants (High-Stiffness (HS): ∅ 5.5 mm Titanium, Medium-Stiffness (MS): ∅ 6.35 x 7.2 mm Oblong PEEK, Low-Stiffness (LS): ∅ 5.5 mm Round PEEK, and Ultra-Low-Stiffness (ULS): ∅ 5.5 mm Rod X), instrumented with strain gauges to measure loads, were tested in each of three specimen conditions simulating degenerative changes: intact, facet destabilization and disc destabilization. Results: Transducers measured implant shear loads to within ±5 N. All implants supported significantly greater shear loads as the specimen was destabilized. The LS and ULS implants supported significantly less load than the HS and MS implants for all specimen conditions. Mean implant loads as a percent of the applied shear load in order of increasing specimen destabilization for the HS implant were: 43, 67 and 76%, for the MS implant were: 32, 56 and 77%, for the LS implant were: 18, 35 and 50%, and for the ULS implant were: 16, 39 and 42%. Standard errors were below 8%. Discussion: An accurate shear load transducer was developed; the methodology is adaptable to many implant designs and materials. Implant shear stiffness significantly affected the shear load-sharing characteristics of the fusion devices. Low-stiffness implants transferred significantly greater loads to the spine, and may possibly enhance the transition to the adjacent, uninstrumented spine in vivo.
Internet Quality of Service: An Overview
Creators: name: Zhao, Weibin
name: Olshefski, David
name: Schulzrinne, Henning G.
Publisher: name: Columbia University
Year: 2000
Subjects: Computer science

description: This paper presents an overview of Internet QoS, covering motivation and considerations for adding QoS to Internet, the definition of Internet QoS, traffic and service specifications, IntServ and DiffServ frameworks, data path operations including packet classification, shaping and policing, basic router mechanisms for supporting QoS, including queue management and scheduling, control path mechanisms such as admission control, policy control and bandwidth brokers, the merging of routing and QoS, traffic engineering, constraint-based routing and multiprotocol label switching (MPLS), as well as end host support for QoS. We identify some important design principles and open issues for Internet QoS.
The mystique surrounding the central bank's balance sheet, applied to the European crisis
Creators: name: Reis, Ricardo
Publisher: name: Columbia University
Year: 2013
Subjects: Economics

description: In spite of the mystique behind a central bank's balance sheet, its resource constraint bounds the dividends it can distribute by the present value of seignorage, which is a modest share of GDP. Moreover, the statutes of the Federal Reserve or the ECB make it difficult for it to redistribute resources across regions. In a simple model of sovereign default, where multiple equilibria arise if debt repudiation lowers fiscal surpluses, the central bank may help to select one equilibrium. The central bank's main lever over fundamentals is to raise inflation, but otherwise the balance sheet gives it little leeway.
Morita homotopy theory of C*-categories
Creators: name: Dell'Ambrogio, Ivo
name: Tabuada, Goncalo
Publisher: name: arXiv
Year: 2011
Subjects: subject: Category Theory (math.CT)
subject: K-Theory and Homology (math.KT)
subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 46M99 (Primary), 46L05, 55U35, 16D90 (Secondary)

description: In this article we establish the foundations of the Morita homotopy theory of C*-categories. Concretely, we construct a cofibrantly generated simplicial symmetric monoidal Quillen model structure M_Mor on the category C*cat1 of small unital C*-categories. The weak equivalences are the Morita equivalences and the cofibrations are the *-functors which are injective on objects. As an application, we obtain an elegant description of the Brown-Green-Rieffel Picard group in the associated Morita homotopy category Ho(M_Mor). We then prove that the Morita homotopy category is semi-additive. By group completing the induced abelian monoid structure at each Hom-set we obtain an additive category Ho(M_Mor)^{-1} and a canonical functor C*cat1 {\to} Ho(M_Mor)^{-1} which is characterized by two simple properties: inversion of Morita equivalences and preservation of all finite products. Finally, we prove that the classical Grothendieck group functor becomes co-represented in Ho(M_Mor)^{-1} by the tensor unit object.
description: 35 pages
Commodity Bundling in the Japanese Non-Life Insurance Industry: Savings-Type Products as Self-Selection Mechanism
Creators: name: Wallner, Klaus
Publisher: name: Columbia University
Year: 1996
Subjects: Economics

description: This paper develops a self-selection explanation for the use of commodity bundling in the case of savings-type casualty insurance in Japan. The institutional characteristics of the savings-cum-insurance bundle are explained in detail. Two alternative models to explain its success are presented. The moral hazard model assumes that casualty insurance claims are cause by unobservable discretionary actions of the insured (lack of care), while the adverse selection model is centered around the assumption that consumers have private information about their exogenous claim probability. The likelihood of a claim is assumed to fall as personal income rises, because preventive safety measures are normal goods and wealthier people therefore purchase more safety. The predictions of these two models are then compared to evidence from casualty insurance in Japan. The adverse selection theory is on balance better supported, while the moral hazard story is inconsistent with some of the institutional and empirical facts.
Dissecting mitogen-activated protein kinase cascades involving arabidopsis MKK6
Creators: name: Zeng, Qingning
Publisher: name: University of British Columbia
Year: 2011

description: Mitogen-activated protein (MAP) kinase cascades act as critical components in the signalling pathways of all eukaryotic cells. They play a pivotal role in the transduction of extra- and intra-cellular stimuli and regulate cell growth, proliferation, differentiation and cell death, through sequential activation of MAP kinase kinase kinases (MAPKKKs), MAP kinase kinases (MKKs), and MAP kinases (MPKs). These three components form modules that control the phosphorylation of various substrates including transcription factors, enzymes, and cytoskeleton-associated proteins. In the Arabidopsis genome, over 60 MAPKKKs (AtMKKK), 10 MAPKKs (AtMKK), and 20 MAPKs (AtMPK) have been identified. The smaller number of AtMKKs suggests that diverse signals may converge and be integrated at the level of AtMKK. Among the ten AtMKKs, MKK6 has been proposed to play a role in regulating cytokinesis. However, little is known about the hierarchal phosphorylation system containing MKK6. In this Ph.D. project, I aimed to dissect the MAP kinase cascades involving MKK6 in Arabidopsis. I investigated potential targets of MKK6. Four MAP kinases were identified to interact with, and be phosphorylated by, MKK6, namely, MPK4, MPK6, MPK11, and MPK13. Among them, MPK13 is developmentally co-expressed with MKK6, and both MPK13 and MKK6 display high Promoter
The physics of galactic winds driven by active galactic nuclei
Creators: name: Faucher-Giguere, C. -A.
name: Quataert, E.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Active galactic nuclei (AGN) drive fast winds in the interstellar medium of their host galaxies. It is commonly assumed that the high ambient densities and intense radiation fields in galactic nuclei imply short cooling times, thus making the outflows momentum-conserving. We show that cooling of high-velocity, shocked winds in AGN is in fact inefficient in a wide range of circumstances, including conditions relevant to ultra-luminous infrared galaxies (ULIRGs), resulting in energy-conserving outflows. We further show that fast energy-conserving outflows can tolerate a large amount of mixing with cooler gas before radiative losses become important. For winds with initial velocity v_in>~10,000 km s^-1, as observed in ultra-violet and X-ray absorption, the shocked wind develops a two-temperature structure. While most of the thermal pressure support is provided by the protons, the cooling processes operate directly only on the electrons. This significantly slows down inverse Compton cooling, while free free cooling is negligible. Slower winds with v_in~1,000 km s^-1, such as may be driven by radiation pressure on dust, can also experience energy-conserving phases but under more restrictive conditions. During the energy-conserving phase, the momentum flux of an outflow is boosted by a factor ~v_in/2v_s by work done by the hot post-shock gas, where v_s is the velocity of the swept-up material. Energy-conserving outflows driven by fast AGN winds (v_in~0.1c) may therefore explain the momentum fluxes Pdot>>L_AGN/c of galaxy-scale outflows recently measured in luminous quasars and ULIRGs. Shocked wind bubbles expanding normal to galactic disks may also explain the large-scale bipolar structures observed in some systems, including around the Galactic Center, and can produce significant radio, X-ray, and gamma-ray emission. [Abridged]
description: 20 pages, 8 figures. MNRAS, in press
One-Fe versus Two-Fe Brillouin Zone of Fe-Based Superconductors: Creation of the Electron Pockets via Translational Symmetry Breaking
Creators: name: Lin, Chia-Hui
name: Berlijn, Tom
name: Wang, Limin
name: Lee, Chi-Cheng
name: Yin, Wei-Guo
name: Ku, Wei
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We investigate the physical effects of translational symmetry breaking in Fe-based high-temperature superconductors due to alternating anion positions. In the representative parent compounds, including the newly discovered Fe-vacancy-ordered $\mathrm{K_{0.8}Fe_{1.6}Se_2}$, an unusual change of orbital character is found across the one-Fe Brillouin zone upon unfolding the first-principles band structure and Fermi surfaces, suggesting that covering a larger one-Fe Brillouin zone is necessary in experiments. Most significantly, the electron pockets (critical to the magnetism and superconductivity) are found only created with the broken symmetry, advocating strongly its full inclusion in future studies, particularly on the debated nodal structures of the superconducting order parameter.
description: Accepted by Physical Review Letters. Updated in Figure 2 and supplementary information
Magnetic field dependence of Pauli spin blockade: a window into the sources of spin relaxation in silicon quantum dots
Creators: name: Yamahata, G.
name: Kodera, T.
name: Churchill, H. O. H.
name: Uchida, K.
name: Marcus, C. M.
name: Oda, S.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate spin relaxation in a silicon double quantum dot via leakage current through Pauli blockade as a function of interdot detuning and magnetic field. A dip in leakage current as a function of magnetic field on a \sim 40 mT field scale is attributed to spin-orbit mediated spin relaxation. On a larger (\sim 400 mT) field scale, a peak in leakage current is seen in some, but not all, Pauli-blocked transitions, and is attributed to spin-flip cotunneling. Both dip and peak structure show good agreement between theory and experiment.
description: supplementary material here: http://marcuslab.harvard.edu/SiDQDsupp.pdf
BaFe2Se2O as an Iron-Based Mott Insulator with Antiferromagnetic Order
Creators: name: Han, Fei
name: Wan, Xiangang
name: Shen, Bing
name: Wen, Hai-Hu
Publisher: name: arXiv
Year: 2012
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: A new compound with a quasi-two-dimensional array of FeSe3O tetrahedra and an orthorombic structure, namely BaFe2Se2O, has been successfully fabricated. Experimental results show that this compound is an insulator and has an antiferromagnetic (AF) transition at 240 K. Band structure calculation reveals the narrowing of Fe 3d bands near the Fermi energy, which leads to the localization of magnetism and the Mott insulating behavior. The large distances between the Fe atoms perhaps are responsible for the characters. Linear response calculation further indicates a strong in-plane AF exchange $J$, this can account for the enhanced magnetic susceptibility (which has a maximum at about 450 K) above the Neel temperature.
description: submitted to PRL on 2 May 2012, resubmitted to PRB on 31 May 2012, and accepted by PRB on 5 July 2012
Design of a Fractional Order Phase Shaper for Iso-damped Control of a PHWR under Step-back Condition
Creators: name: Saha, Suman
name: Das, Saptarshi
name: Ghosh, Ratna
name: Goswami, Bhaswati
name: Balasubramanian, R.
name: Chandra, A. K.
name: Das, Shantanu
name: Gupta, Amitava
Publisher: name: arXiv
Year: 2012
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Phase shaping using fractional order (FO) phase shapers has been proposed by many contemporary researchers as a means of producing systems with iso-damped closed loop response due to a stepped variation in input. Such systems, with the closed loop damping remaining invariant to gain changes can be used to produce dead-beat step response with only rise time varying with gain. This technique is used to achieve an active step-back in a Pressurized Heavy Water Reactor (PHWR) where it is desired to change the reactor power to a pre-determined value within a short interval keeping the power undershoot as low as possible. This paper puts forward an approach as an alternative for the present day practice of a passive step-back mechanism where the control rods are allowed to drop during a step-back action by gravity, with release of electromagnetic clutches. The reactor under a step-back condition is identified as a system using practical test data and a suitable Proportional plus Integral plus Derivative (PID) controller is designed for it. Then the combined plant is augmented with a phase shaper to achieve a dead-beat response in terms of power drop. The fact that the identified static gain of the system depends on the initial power level at which a step-back is initiated, makes this application particularly suited for using a FO phase shaper. In this paper, a model of a nuclear reactor is developed for a control rod drop scenario involving rapid power reduction in a 500MWe Canadian Deuterium Uranium (CANDU) reactor using AutoRegressive Exogenous (ARX) algorithm. The system identification and reduced order modeling are developed from practical test data. For closed loop active control of the identified reactor model, the fractional order phase shaper along with a PID controller is shown to perform better than the present Reactor Regulating System (RRS) due to its iso-damped nature.
description: 11 pages, 10figures
Archives in the Digital Age
Creators: name: Erway, Ricky
Publisher: name: Columbia University
Year: 2010
Subjects: subject: Archives
subject: Archival materials--Conservation and restoration
subject: Electronic records
subject: Electronic records--Law and legislation
subject: Libraries--Special collections
subject: Intellectual property
subject: Law
subject: FOS: Law

description: "I understand my role is to convey the scope of “digital archives,” so that we’re all on the same page, talking about the entire range of what’s included in “digital archives.” And first, I’d like to say a little something about archives in relation to special collections. Archives can refer to things like official records of a corporation or institution, personal papers, literary manuscripts, but they also contain photo collections, recorded sound, clippings and, often, combinations of these things. Special collections can refer to these same things, and sometimes archives units are actually part of special collections divisions."
Constructive spherical codes on layers of flat tori
Creators: name: Torezzan, Cristiano
name: Costa, Sueli I. R.
name: Vaishampayan, Vinay A.
Publisher: name: arXiv
Year: 2012
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: A new class of spherical codes is constructed by selecting a finite subset of flat tori from a foliation of the unit sphere S^{2L-1} of R^{2L} and designing a structured codebook on each torus layer. The resulting spherical code can be the image of a lattice restricted to a specific hyperbox in R^L in each layer. Group structure and homogeneity, useful for efficient storage and decoding, are inherited from the underlying lattice codebook. A systematic method for constructing such codes are presented and, as an example, the Leech lattice is used to construct a spherical code in R^{48}. Upper and lower bounds on the performance, the asymptotic packing density and a method for decoding are derived.
description: 9 pages, 5 figures, submitted to IEEE Transactions on Information Theory
Formalization and applications of the precautionary principles
Creators: name: Henry, Claude
name: Henry, Marc
Publisher: name: Columbia University
Year: 2002
Subjects: Economics

description: A formalization of the Precautionary Principle is given here: We formalize scientific knowledge on the likelihood of events in the state space and the concepts of scientifically unambiguous events and acts. We give a definition of a non-precautionary social planner as a Savage Expected Utility maximizer who evaluates acts relative to a baseline, called "business as usual," and who disregards scientifically ambiguous acts, and we show that, for a wide class of preferences for the representative agent, non-precautionary decision making is sub-optimal. A discussion of this formalization is given in the context of national and international debates on Precaution, in the fields of Climate Change, of WTO arbitrages, and of the safety regulations of chemical products.
Additional file 1 of Prevalence and correlates of poor sleep quality among college students: a cross-sectional survey
Creators: name: Li, Yuanyuan
name: Bai, Wei
name: Zhu, Bo
name: Duan, Ruixin
name: Yu, Xiao
name: Xu, Wen
name: Wang, Mohan
name: Hua, Wanqing
name: Yu, Weiying
name: Li, Wenjun
name: Kou, Changgui
Publisher: name: figshare
Year: 2020
Subjects: Medicine
Neuroscience
Biological Sciences not elsewhere classified
Science Policy
Mental Health

description: Additional file 1 Appendix 1. The assignment of the variables included in the logistic regression. Appendix 2. PSQI component scores and total scores (M ± SD) in all participants and by gender.
Effects of a Companion Star on Slow Nova Outbursts -- Transition from Static to Wind Evolutions
Creators: name: Kato, Mariko
name: Hachisu, Izumi
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Two types of nova evolutions can be realized in low mass white dwarfs of ~0.5-0.7 M_sun, i.e., an evolution with optically thick winds like in usual classical novae, or an another type of evolution without them like in the symbiotic nova PU Vul. The latter type is characterized by spectra of no indication of strong winds as well as a long-lasted flat optical peak in its light curve. We propose a transition from no-optically-thick-wind evolution to usual evolution with optically thick winds as a new outburst model for slow novae that show a relatively long-lasted multipeak phase followed by a wind phase like in the slow novae V723 Cas, HR Del, and V5558 Sgr. We calculated nova envelopes with one-dimensional approximation of the companion's effects and found that when the companion star is deeply embedded in the extended nova envelope, the structure of static envelope approaches that of the optically thick wind solution. Thus, the transition from static to wind solution is triggered by the effect of the companion. The transition occurs in a close binary nova like V723 Cas, but is not triggered in a long period binary like PU Vul. We reconfirm our previous results that the frictional energy deposition is negligibly small in almost all of hydrogen/helium novae because of the low envelope density at the orbit.
description: 11 pages, 7 figures, to appear in ApJ, (reference revised)
Almost Everybody Disagrees Almost All the Time: The Genericity of Weakly-Merging Nowhere
Creators: name: Miller, Ronald I.
name: Sanchirico, Chris William
Publisher: name: Columbia University
Year: 1997
Subjects: Economics

description: Suppose we randomly pull two agents from a population and ask them to observe an unfolding, infinite sequence of zeros and ones. If each agent starts with a prior belief about the true sequence and updates this belief on revelation of successive observations, what is the chance that the two agents will come to agree on the likelihood that the next draw is a one? In this paper we show that there is no chance. More formally, we show that under a very unrestrictive definition of what it means to draw priors "randomly," the probability that two priors have any chance of weakly merging is zero. Indeed, almost surely, the two measures will be singular—one prior will think certain to occur a set of sequences that the other thinks impossible, and vice versa. Our result is meant as a critique of the "rational learning" literature, which seeks positive convergence results on infinite product spaces by augmenting the process of Bayesian updating with seeming regularity conditions, variously labeled "consistency" or "compatibility" assumptions. Our object is to investigate just how regular these assumption and results are when considered in the space of all possible prior distributions. Our results on the genericity of nowhere weak merging and singularity speak not just to the specific assumptions and results that appear in the literature, but to the "rational learning" approach generally. We call instead for a different approach to learning, one that recognizes the necessity of genuine, substantive restrictions on beliefs and proposes "extra rational" restrictions that are explicitly grounded in our best understanding of human behavior, ideally gleaned from experimental data.
Improved Eavesdropping Detection Strategy in Quantum Direct Communication Protocol Based on Four-particle GHZ State
Creators: name: Li, Jian
name: Jin, Haifei
name: Jing, Bo
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In order to improve the eavesdropping detection efficiency in two-step quantum direct communication protocol, an improved eavesdropping detection strategy using four-particle GHZ state is proposed, in which four-particle GHZ state is used to detect eavesdroppers. During the security analysis, the method of the entropy theory is introduced, and two detection strategies are compared quantitatively by using the constraint between the information which eavesdropper can obtain and the interference introduced. If the eavesdroppers intend to obtain all information, the eavesdropping detection rate of the original two-step quantum direct communication protocol by using EPR pair block as detection particles is 50%; while the proposed strategy's detection rate is 88%. In the end, the security of the proposed protocol is discussed. The analysis results show that the eavesdropping detection strategy presented is more secure.
description: 14 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:quant-ph/0308173 by different authors