Report of Investigations No. 123 Petroleum Potential of the Palo Duro Basin, Texas Panhandle

UT Librarie

Tracking environmental trends in the Great Bay Estuarine System through comparisons of historical and present-day green and red algal community structure and nutrient content

Monitoring macroalgae populations is an effective means of detecting long term water quality changes in estuarine systems. To investigate the environmental status of New Hampshire’s Great Bay National Estuarine Research Reserve, this study assessed the abundance/distribution of macrophytes, particularly Gracilaria and Ulva species, relative to eutrophication patterns; compared historical (1970s-1990s) and current algal biomass/cover at several sites; and compared Ulva and Gracilaria tissue N/P content to ambient and historical levels. Ulva and Gracilaria biomass/cover have increased significantly at several sites. Cover by Ulva species, at seasonal maxima, was over 90 times the value recorded in the 1970s at Lubberland Creek, and exceeded 50% at all sites in the upper estuary. Gracilaria cover was greater than 25% at Depot Road in the upper estuary, whereas the historical measure was 1%. Sequencing of ITS2, rbcL and CO1 revealed the presence of previously undetected Ulva and Gracilaria species, including Gracilaria vermiculophylla (Ohmi) Papenfuss, an invasive species of Asian origin. Gracilaria vermiculophylla has exceeded G. tikvahiae as the dominant Gracilaria species in Great Bay. Historical voucher specimen screening suggests G. vermiculophylla was introduced as recently as 2003. Nitrogen and phosphorus levels are elevated in the estuary. We should expect continued seasonal nuisance algal blooms

Metallicity Evolution in the Early Universe

Observations of the damped Lya systems provide direct measurements on the chemical enrichment history of neutral gas in the early universe. In this Letter, we present new measurements for four damped Lya systems at high redshift. Combining these data with [Fe/H] values culled from the literature, we investigate the metallicity evolution of the universe from z~1.5-4.5. Contrary to our expectations and the predictions of essentially every chemical evolution model, the N(HI)-weighted mean [Fe/H] metallicity exhibits minimal evolution over this epoch. For the individual systems, we report tentative evidence for an evolution in the unweighted [Fe/H] mean and the scatter in [Fe/H] with the higher redshift systems showing lower scatter and lower typical [Fe/H] values. We also note that no damped Lya system has [Fe/H] < -2.7 dex. Finally, we discuss the potential impact of small number statistics and dust on our conclusions and consider the implications of these results on chemical evolution in the early universe.Comment: 6 pages, 2 encapsulated figures, Latex2e, uses emulateapj.sty and onecolfloat.sty. Accepted for publication in ApJ Letters: Feb 28, 200

Voices in the mental lexicon: Words carry indexical information that can affect access to their meaning

Available online 11 May 2019The speech signal carries both linguistic and non-linguistic information (e.g., a talker’s voice qualities; referred to as indexical information). There is evidence that indexical information can affect some aspects of spoken word recognition, but we still do not know whether and how it can affect access to a word’s meaning. A few studies support a dual-route model, in which inferences about the talker can guide access to meaning via a route external to the mental lexicon. It remains unclear whether indexical information is also encoded within the mental lexicon. The present study tests for indexical effects on spoken word recognition and referent selection within the mental lexicon. In two experiments, we manipulated voice-to-referent co-occurrence, while preventing participants from using indexical information in an explicit way. Participants learned novel words (e.g., bifa) and their meanings (e.g., kite), with each talker’s voice linked (via systematic co-occurrence) to a specific referent (e.g., bifa spoken by speaker 1 referred to a specific picture of a kite). In testing, voice-to-referent mapping either matched that of training (congruent), or not (incongruent). Participants’ looks to the target’s referent were used as an index of lexical activation. Listeners looked faster at a target’s referent on congruent than incongruent trials. The same pattern of results was observed in a third experiment, when testing was 24 hrs later. These results show that indexical information can be encoded in lexical representations and affect spoken word recognition and referent selection. Our findings are consistent with episodic and distributed views of the mental lexicon that assume multi-dimensional lexical representations.Support for this project was provided by the Spanish Ministry of Science and Innovation, Grant # PSI2014-53277 and # PSI2017-82563- P awarded to A.G.S., the Spanish Ministry of Economy and Competitiveness, Juan de la Cierva-Formación fellowship awarded to E.C.K., and the Spanish Ministry of Economy and Competitiveness, “Severo Ochoa” Programme for Centres/Units of Excellence in R&D (SEV‐2015‐490)

Reconciling the Contradictory Effects of Production on Word Learning: Production May Help at First, but It Hurts Later

Published: March 2022Does saying a novel word help to recognize it later? Previous research on the effect of production on this aspect of word learning is inconclusive, as both facilitatory and detrimental effects of production are reported. In a set of three experiments, we sought to reconcile the seemingly contrasting findings by disentangling the production from other effects. In Experiment 1, participants learned eight new words and their visual referents. On each trial, participants heard a novel word twice: either (a) by hearing the same speaker produce it twice (Perception-Only condition) or (b) by first hearing the speaker once and then producing it themselves (Production condition). At test, participants saw two pictures while hearing a novel word and were asked to choose its correct referent. Experiment 2 was identical to Experiment 1, except that in the Perception-Only condition each word was spoken by 2 different speakers (equalizing talker variability between conditions). Experiment 3 was identical to Experiment 2, but at test words were spoken by a novel speaker to assess generalizability of the effect. Accuracy, reaction time, and eye-movements to the target image were collected. Production had a facilitatory effect during early stages of learning (after short training), but its effect became detrimental after additional training. The results help to reconcile conflicting findings regarding the role of production on word learning. This work is relevant to a wide range of research on human learning in showing that the same factor may play a different role at different stages of learning.Support for this project was provided by the Spanish Ministry of Science and Innovation, Grant PSI2017-82563-P, awarded to Arthur G. Samuel and by the Spanish Ministry of Economy and Competitiveness through the Juan de la Cierva-Formación fellowship, FJCI-2016–28019, awarded to Efthymia C. Kapnoula. This work was partially supported by the Basque Government through the BERC 2018–2021 and BERC 2022–2025 programs, and by the Spanish State Research Agency through BCBL Severo Ochoa excellence accreditation SEV-2015-0490 and CEX2020-001010-S. This project has received funding from the European Union’s Horizon 2020 research and innovation program, under the Marie Skłodowska-Curie grant agreement 793919, awarded to Efthymia C. Kapnoula

Gravitational Leakage into Extra Dimensions: Probing Dark Energy Using Local Gravity

The braneworld model of Dvali-Gabadadze-Porrati (DGP) is a theory where gravity is modified at large distances by the arrested leakage of gravitons off our four-dimensional universe. Cosmology in this model has been shown to support both "conventional" and exotic explanations of the dark energy responsible for today's cosmic acceleration. We present new results for the gravitational field of a clustered matter source on the background of an accelerating universe in DGP braneworld gravity, and articulate how these results differ from those of general relativity. In particular, we show that orbits nearby a mass source suffer a universal anomalous precession as large as 5 microarcseconds/year, dependent only on the graviton's effective linewidth and the global geometry of the full, five-dimensional universe. Thus, this theory offers a local gravity correction sensitive to factors that dictate cosmological history.Comment: 18 pages, 1 figure, revtex. Reference updated. Footnote change

Communications of the lunar planetary laboratory, volume 3, no. 40- the system of lunar craters, quadrant ii

Observable properties of craters in second lunar quadran

Distribution of Damped Lyman-alpha Absorbers in a Lambda Cold Dark Matter Universe

We present the results of a numerical study of a galactic wind model and its implications on the properties of damped Lyman-alpha absorbers (DLAs) using cosmological hydrodynamic simulations. We vary both the wind strength and the internal parameters of the the wind model in a series of cosmological SPH simulations that include radiative cooling and heating by a UV background, star formation, and feedback from supernovae and galactic winds. To test our simulations, we examine the DLA `rate-of-incidence' as a function of halo mass, galaxy apparent magnitude, and impact parameter. We find that the statistical distribution of DLAs does not depend on the exact values of internal numerical parameters that control the decoupling of hydrodynamic forces when the gas is ejected from starforming regions. The DLA rate-of-incidence in our simulations at z=3 is dominated by the faint galaxies with apparent magnitude R_AB < 25.5. However, interestingly in a `strong wind' run, the differential distribution of DLA sight-lines is peaked at Mhalo = 10^{12} Msun/h (R_AB~27), and the mean DLA halo mass is Mmean=10^{12.4} Msun/h (R_AB ~ 26). These mass-scales are much larger than those if we ignore winds, because galactic wind feedback suppresses the DLA cross section in low-mass halos and increases the relative contribution to the DLA incidence from more massive halos. The DLAs in our simulations are more compact than the present-day disk galaxies, and the impact parameter distribution is very narrow unless we limit the search for the host galaxy to only bright LBGs. The comoving number density of DLAs is higher than that of LBGs down to R_AB=30 mag if the physical radius of each DLA is smaller than 5 kpc/h_70. We discuss conflicts between current simulations and observations, and potential problems with simulations based on the CDM model.Comment: 37 pages, 11 figures. Accepted to ApJ. Additional numerical tests of the internal parameters of the galactic wind model are presente