6,592 research outputs found

    Dismantling Lamarckism: why descriptions of socio-economic evolution as Lamarckian are misleading

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    “The original publication is available at www.springerlink.com”. Copyright Springer.This paper addresses the widespread tendency to describe socio-economic evolution as Lamarckian. The difference between Lamarckian and Darwinian replication is clarified. It is shown that a phenotype-genotype distinction must first be established before we can identify Lamarckian transmission. To qualify as Lamarckian inheritance, acquired properties at the phenotypic level must be encoded in a genotype that is passed on to the next generation. Some possible social replicators (or genotypes) are identified, with a view to exploring possible distinctions between genotype and phenotype at the social level. It is concluded that the Lamarckian label does not readily transfer to socio-economic evolution, despite the fact that social genotypes (such as routines) may adapt within any given phenotype (such as an organisation). By contrast, no such problems exist with the description of socio-economic evolution as Darwinian.Peer reviewe

    Computer program developed for flowsheet calculations and process data reduction

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    Computer program PACER-65, is used for flowsheet calculations and easily adapted to process data reduction. Each unit, vessel, meter, and processing operation in the overall flowsheet is represented by a separate subroutine, which the program calls in the order required to complete an overall flowsheet calculation

    Physical properties and morphology of a newly identified compact z=4.04 lensed submillimeter galaxy in Abell 2218

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    We present the identification of a bright submm source, SMMJ163555.5+661300, detected in the lensing cluster Abell2218, for which we have accurately determined the position using observations from the Submillimeter Array (SMA). The identified optical counterpart has a spectroscopic redshift of z=4.044+-0.001 if we attribute the single emission line detected at lambda=6140AA to Lyman-alpha. This redshift identification is in good agreement with the optical/near-infrared photometric redshift as well as the submm flux ratio S_450/S_850~1.6, the radio-submm flux ratio S_1.4/S_850 < 0.004, and the 24um to 850um flux ratio S_24/S_850 < 0.005. Correcting for the gravitational lensing amplification of ~5.5, we find that the source has a far-infrared luminosity of 1.3x10^12 Lsun, which implies a star formation rate of 230 Msun/yr. This makes it the lowest-luminosity SMG known at z>4 to date. Previous CO(4-3) emission line obserations yielded a non-detection, for which we derived an upper limit of the CO line luminosity of L'_CO = 0.3x10^10 K km/s/pc^2, which is not inconsistent with the L'_CO - L_FIR relation for starburst galaxies. The best fit model to the optical and near-infrared photometry give a stellar population with an age of 1.4 Gyr and a stellar mass of 1.6x10^10 Msun. The optical morphology is compact and in the source plane the galaxy has an extent of ~6kpc x 3kpc with individual star forming knots of <500 pc in size. J163556 is not resolved in the SMA data and we place a strict upper limit on the size of the starburst region of 8kpc x 3kpc, which implies a lower limit on the star formation rate surface density of 12 Msun/yr/kpc^2. The redshift of J163556 extends the redshift distribution of faint, lensed SMGs, and we find no evidence that these have a different redshift distribution than bright SMGs.Comment: Accepted for publication in ApJ. 11 pages, 7 figure

    Vertex Fault Tolerant Additive Spanners

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    A {\em fault-tolerant} structure for a network is required to continue functioning following the failure of some of the network's edges or vertices. In this paper, we address the problem of designing a {\em fault-tolerant} additive spanner, namely, a subgraph HH of the network GG such that subsequent to the failure of a single vertex, the surviving part of HH still contains an \emph{additive} spanner for (the surviving part of) GG, satisfying dist(s,t,H{v})dist(s,t,G{v})+βdist(s,t,H\setminus \{v\}) \leq dist(s,t,G\setminus \{v\})+\beta for every s,t,vVs,t,v \in V. Recently, the problem of constructing fault-tolerant additive spanners resilient to the failure of up to ff \emph{edges} has been considered by Braunschvig et. al. The problem of handling \emph{vertex} failures was left open therein. In this paper we develop new techniques for constructing additive FT-spanners overcoming the failure of a single vertex in the graph. Our first result is an FT-spanner with additive stretch 22 and O~(n5/3)\widetilde{O}(n^{5/3}) edges. Our second result is an FT-spanner with additive stretch 66 and O~(n3/2)\widetilde{O}(n^{3/2}) edges. The construction algorithm consists of two main components: (a) constructing an FT-clustering graph and (b) applying a modified path-buying procedure suitably adopted to failure prone settings. Finally, we also describe two constructions for {\em fault-tolerant multi-source additive spanners}, aiming to guarantee a bounded additive stretch following a vertex failure, for every pair of vertices in S×VS \times V for a given subset of sources SVS\subseteq V. The additive stretch bounds of our constructions are 4 and 8 (using a different number of edges)

    Development of Spatial Preferences for Counting and Picture Naming

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    The direction of object enumeration reflects children’s enculturation but previous work on the development of such spatial preferences has been inconsistent. Therefore, we documented directional preferences in finger counting, object counting, and picture naming for children (4 groups from 3 to 6 years, N = 104) and adults (N = 56). We found a right-side preference for finger counting in 3- to 6-year-olds and a left-side preference for counting objects and naming pictures by 6 years of age. Children were consistent in their special preferences when comparing object counting and picture naming, but not in other task pairings. Finally, spatial preferences were not related to cardinality comprehension. These results, together with other recent work, suggest a gradual development of spatial-numerical associations from early non-directional mappings into culturally constrained directional mappings

    Origin and significance of 'dispersed facies' basal ice: Svínafellsjökull, Iceland

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    Dispersed facies basal ice - massive (i.e. structureless) ice with dispersed debris aggregates - is present at the margins of many glaciers and, as a product of internal glacial processes, has the potential to provide important information about the mechanisms of glacier flow and the nature of the subglacial environment. The origin of dispersed facies is poorly understood, with several hypotheses having been advanced for its formation, and there is disagreement as to whether it is largely a sedimentary or a tectonic feature. We test these established hypotheses at the temperate glacier Svfnafellsjokull, Iceland, and find that none fully account for dispersed facies characteristics at this location. Instead, dispersed facies physical, sedimentological and stable-isotope (5180, 8D) characteristics favour a predominantly tectonic origin that we suggest comprises the regelation and straininduced metamorphism of debris-rich basal ice that has been entrained into an englacial position by tectonic processes operating at the base of an icefall. Further thickening of the resultant dispersed facies may also occur tectonically as a result of ice flow against the reverse bed slope of a terminal overdeepening. Lack of efficient subglacial drainage in the region of the overdeepening may limit basal melting and thus favour basal ice preservation, including the preservation of dispersed facies. Despite the relatively low sediment content of dispersed facies (~1.6% by volume), its thickness (up to 25 m) and ubiquity at Svfnafellsjokull results in a significant contribution to annual sediment discharge (1635-3270 m3 a"1) that is ~6.5 times that contributed by debris-rich stratified facies basal ice

    Shear-Wave Velocity Characterization of the USGS Hawaiian Strong-Motion Network on the Island of Hawaii and Development of an NEHRP Site-Class Map

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    To assess the level and nature of ground shaking in Hawaii for the purposes of earthquake hazard mitigation and seismic design, empirical ground-motion prediction models are desired. To develop such empirical relationships, knowledge of the subsurface site conditions beneath strong-motion stations is critical. Thus, as a first step to develop ground-motion prediction models for Hawaii, wspectral-analysis-of-surface-waves (SASW) profiling was performed at the 22 free-field U.S. Geological Survey (USGS) strong-motion sites on the Big Island to obtain shear-wave velocity (V(S)) data. Nineteen of these stations recorded the 2006 Kiholo Bay moment magnitude (M) 6.7 earthquake, and 17 stations recorded the triggered M 6.0 Mahukona earthquake. V(S) profiling was performed to reach depths of more than 100 ft. Most of the USGS stations are situated on sites underlain by basalt, based on surficial geologic maps. However, the sites have varying degrees of weathering and soil development. The remaining strong-motion stations are located on alluvium or volcanic ash. V(S30) (average V(S) in the top 30 m) values for the stations on basalt ranged from 906 to 1908 ft/s [National Earthquake Hazards Reduction Program (NEHRP) site classes C and D], because most sites were covered with soil of variable thickness. Based on these data, an NEHRP site-class map was developed for the Big Island. These new V(S) data will be a significant input into an update of the USGS statewide hazard maps and to the operation of ShakeMap on the island of Hawaii.George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) under NSF CMS-0086605FEMA HSFEHQ-06-D-0162, HSFEHQ-04-D-0733U.S. Geological Survey, Department of the Interior 08HQGR0036Geotechnical Engineering Cente
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