Bring ART into the ACT

ACT is compared with a particular type of connectionist model that cannot handle symbols and use non-biological operations that cannot learn in real time. This focus continues an unfortunate trend of straw man "debates" in cognitive science. Adaptive Resonance Theory, or ART, neural models of cognition can handle both symbols and sub-symbolic representations, and meets the Newell criteria at least as well as these models.Air Force Office of Scientific Research (F49620-01-1-0397); Office of Naval Research (N00014-01-1-0624

The MOSDEF Survey: Detection of [OIII]λ\lambda4363 and the direct-method oxygen abundance of a star-forming galaxy at z=3.08

We present measurements of the electron-temperature based oxygen abundance for a highly star-forming galaxy at z=3.08, COSMOS-1908. This is the highest redshift at which [OIII]$\lambda$4363 has been detected, and the first time that this line has been measured at z>2. We estimate an oxygen abundance of 12+log(O/H)$=8.00^{+0.13}_{-0.14}$. This galaxy is a low-mass ($10^{9.3}$ M$_{\odot}$), highly star-forming ($\sim50$ M$_{\odot}$ yr$^{-1}$) system that hosts a young stellar population ($\sim160$ Myr). We investigate the physical conditions of the ionized gas in COSMOS-1908 and find that this galaxy has a high ionization parameter, little nebular reddening ($E(B-V)_{\rm gas}<0.14$), and a high electron density ($n_e\sim500$ cm$^{-3}$). We compare the ratios of strong oxygen, neon, and hydrogen lines to the direct-method oxygen abundance for COSMOS-1908 and additional star-forming galaxies at z=0-1.8 with [OIII]$\lambda$4363 measurements, and show that galaxies at z$\sim$1-3 follow the same strong-line correlations as galaxies in the local universe. This agreement suggests that the relationship between ionization parameter and O/H is similar for z$\sim$0 and high-redshift galaxies. These results imply that metallicity calibrations based on lines of oxygen, neon, and hydrogen do not strongly evolve with redshift and can reliably estimate abundances out to z$\sim$3, paving the way for robust measurements of the evolution of the mass-metallicity relation to high redshift.Comment: 7 pages, 3 figures, 1 table, accepted to ApJ Letter

Light converts endosymbiotic fungus to pathogen, influencing seedling survival and host tree recruitment

Endophytic fungi that asymptomatically colonize plants^1^ are diverse and abundant in tropical ecosystems^2^. These organisms can be weakly pathogenic^3^ and/or mutualistic, frequently enabling plants to adapt to extreme environments, alter competitive abilities of host individuals and improve host fitness under abiotic or biotic stresses^4,5,6^. _Diplodia mutila_ is a symbiotic endophyte/plant pathogenic fungus infecting the palm _Iriartea deltoidea_^7^, which dominates many wet lowland Neotropical forests. The fungus is an asymptomatic endophyte in mature plants, and disease and mortality are expressed in some seedlings, while others remain disease free. Here we show that seedlings bearing the endophyte show enhanced resistance to insect herbivory. However, high light availability triggers pathogenicity of the fungus, while low light favors endosymbiotic development, constraining recruitment of endophyte-infested seedlings to the shaded understory by limiting survival of seedlings in direct light. These results provide evidence that patterns of plant abundance and the mechanisms maintaining tropical forest biodiversity are the result of a more complex interplay between abiotic and biotic environments than previously thought

A biometrical approach to evolving a selection index for seed parents in coconut (Cocos nucifera L.)

An efficiency selection index for mother palms in coconut is evolved through the technique of principal component analysis. This index helps to select the superior genotypes through characters in the palm that can be measured at a given instant as against the present questionable system of selecting the superior phenotypes as mother palms and that too through yield data gathered over a period of as long as four years. The use of this index as a calibrating variate field experiments on coconut is also reommended in order to improve experimental precision

X 1908+075: An X-ray Binary with a 4.4 day Period

X 1908+075 is an optically unidentified and highly absorbed X-ray source that appears in early surveys such as Uhuru, OSO-7, Ariel V, HEAO-1, and the EXOSAT Galactic Plane Survey. These surveys measured a source intensity in the range of 2-12 mCrab at 2-10 keV, and the position was localized to ~ 0.5 degrees. We use the Rossi X-ray Timing Explorer (RXTE) All Sky Monitor (ASM) to confirm our expectation that a particular Einstein IPC detection (1E 1908.4+0730) provides the correct position for X 1908+075. The analysis of the coded mask shadows from the ASM for the position of 1E 1908.4+0730 yields a persistent intensity ~ 8 mCrab (1.5-12 keV) over a 3 year interval beginning in 1996 February. Furthermore, we detect a period of 4.400 +- 0.001 days with a false alarm probability < 1.0e-7 . The folded light curve is roughly sinusoidal, with an amplitude that is 22 % of the mean flux. The X-ray period may be attributed to the scattering and absorption of X-rays through a stellar wind combined with the orbital motion in a binary system. We suggest that X 1908+075 is an X-ray binary with a high mass companion star.Comment: 6 pages, two-column,"emulateapj" style, submitted to Ap

Drug-related mutational patterns in hepatitis B virus (HBV) reverse transcriptase proteins from Iranian treatment-Naïve chronic HBV patients

Background: Immunomodulators and Nucleotide analogues have been used globally for the dealing of chronic hepatitis B virus (HBV) infection. However, the development of drug resistance is a major limitation to their long-term effectiveness. Objectives: The aim of this study was to characterize the hepatitis B virus reverse transcriptase (RT) protein variations among Iranian chronic HBV carriers who did not receive any antiviral treatments. Materials and Methods: Hepatitis B virus partial RT genes from 325 chronic in active carrier patients were amplified and directly sequenced. Nucleotide/amino acid substitutions were identified compared to the sequences obtained from the database. Results: All strains belonging to genotype D.365 amino-acid substitutions were found. Mutations related to lamivudine, adefovir, telbivudine, and entecavir occurred in (YMDD) 4% (n = 13), (SVQ) 17.23% (n = 56), (M204I/V + L180M) 2.45% (n = 8) and (M204I) 2.76% (n = 9) of patients, respectively. Conclusions: RT mutants do occur naturally and could be found in HBV carriers who have never received antiviral therapy. However, mutations related to drug resistance in Iranian treatment-naïve chronic HBV patients were found to be higher than other studies published formerly. Chronic HBV patients should be monitored closely prior the commencement of therapy to achieve the best regimen option. © 2013, KOWSAR Corp

Carbon Emissions from Managed Upland Peat

Upland peat is the world's largest store of soil carbon and one of the most climatically sensitive. Concerns have been raised about the stability of the carbon within these stores and how upland peat will respond to climate change. Climate change is predicted to increase average, ~axirnum and minimum temperatures and also reduce summer rainfall in the UK. This predicted change in climate is hypothesised to reduce water table depth and increase soil respiration in upland peat causing upland peat to, potentially, turn from a net sink of carbon into a carbon net source. A range of management practises have been and are being carried out in the UK uplands, often with the view to increase grazing density or increase other commercial animal species such as grouse. This qualifies peat as grazed land under the ratified Kyoto protocol, and any demonstrated increase in carbon storage potential can be used to offset carbon emissions from the UK. Therefore, questions have been raised as to the best management practises for carbon storage potential. By demonstrating that restoration of water table depths in upland peat will reduce CO2 emissions sufficiently above the corresponding increase in CHt emissions associated with water table rise, .carbon stores can be stabilised and the carbon storage rate potentially increased. This thesis reports the results from a study of C02, both gaseous and dissolved, and CHt fluxes across a differential water table, allowing the results to .be analysed both spatially and temporally. From these results a model was constructed from literature and observations, considering dissolved and gaseous CO2as being produced by a single mechanism from within soil processes, where hydrological functions, such as rainfall to determine the endpoint for CO2. The model was used to analyse for the lowest level of monitoring that still gives a good estimate of the carbon budget for the field site by using mass balance equations from hydrological literature. To determine whether the model was valid for higher temperatures and lower water table depths, as predicted for climate change, a series of deep peat cores were sampled from the same site as the spatial and temporal study of CO2flux and moved to a warmer and drier site. When C02 data, measured from the peat cores, was compared to the spatial and temporal CO2fluxes a visual correlation was found between gross C02 flux for the two data sets, however upon statistical analysis it was shown that the data sets were incomparable for gross, net and primary productivity fluxes. Closed chamber measurements of CO2 flux from the spatial and temporal study were compared to eddy covariance measures of CO2flux. It was found that short term (hourly/daily) were poorly correlated whilst longer term (weekly - monthly) fluxes were better correlated. By studying a peatland on the boundary of peats temperature tolerance, this study can be applied to other peatlands to proved a model of expected responses to climate change for peat both in the UK and around the world.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Leaflets of Philippine botany.

v.1 (1906-1908

The Tiger, November 1, 1908

https://scholarlycommons.pacific.edu/pacifican/3690/thumbnail.jp