Prior Knowledge and Age Effects in Memory: Implications for Episodic and Short-term/ Immediate Memory

The ageing literature shows robust age-related declines in immediate (e.g. Bopp & Verhaeghen, 2005; Multhaup, Balota & Cowan, 1996; Verhaeghen, 2002; Verhaeghen, Marcoen & Goosens, 1993) and episodic memory (Fleischman, Wilson, Gabrieli, Bienias & Bennett, 2004; Park, 2000; Schaie, 2005; Singer, Lindenberger & Baltes, 2003). However, older adults also consistently show stable or even improving levels of semantic knowledge (Surprenant & Neath, 2007). In younger adults, Hemmer and Steyvers (2009) showed that episodic memory for the properties (i.e. size) of familiar items is influenced by multiple levels of pre-existing knowledge. In this thesis, I developed their paradigm to systematically explore these knowledge effects in healthy ageing for both episodic memory and short-term/ immediate memory. This was done by comparing memory for familiar relative to unfamiliar faces, as well as for the size of familiar everyday objects relative to unfamiliar, random shapes. Across all experiments, both age groups appeared to rely on pre-existing item-based knowledge for the familiar items to the same extent, suggesting no age-related decrement in the use of prior knowledge. Moreover, the result showed that item-specific knowledge for the unfamiliar items develops over the course of the experiment. This became apparent in cases when the distribution of target item sizes was bimodal, as this made session-based learning of the item statistics easier to observe; this experiment-based knowledge/ learning was again equivalent for both age groups. The older adults, however, consistently demonstrated greater reconstruction variability and overall error. I interpreted this as evidence of noisier memory representations of the studied items for the older adults (e.g. Noack, Lovden & Lindenberger, 2014); the findings suggest that this increase in error does not lead to more knowledge-based bias in older adults. Knowledge and age effects on memor

Geodynamic setting and origin of the Oman/UAE ophiolite

The ~500km-long mid-Cretaceous Semail nappe of the Sultanate of Oman and UAE (henceforth referred to as the Oman ophiolite) is the largest and best-preserved ophiolite complex known. It is of particular importance because it is generally believed to have an internal structure and composition closely comparable to that of crust formed at the present-day East Pacific Rise (EPR), making it our only known on-land analogue for ocean lithosphere formed at a fast spreading rate. On the basis of this assumption Oman has long played a pivotal role in guiding our conceptual understanding of fast-spreading ridge processes, as modern fast-spread ocean crust is largely inaccessible

Quality of life among adolescents with sickle cell disease: Mediation of pain by internalizing symptoms and parenting stress

<p>Abstract</p> <p>Background</p> <p>This study aimed to clarify associations between pain, psychological adjustment, and family functioning with health-related quality of life (HRQOL) in a sample of adolescents with sickle cell disease (SCD) utilizing teen- and parent-report.</p> <p>Methods</p> <p>Forty-two adolescents (between the ages of 12 and 18) with SCD and their primary caregivers completed paper-and-pencil measures of pain, teen's psychological adjustment, and HRQOL. In addition, primary caregivers completed a measure of disease-related parenting stress. Medical file review established disease severity.</p> <p>Results</p> <p>Pearson correlations identified significant inverse associations of pain frequency with physical and psychosocial domains of HRQOL as rated by the teen and primary caregiver. Generally, internalizing symptoms (i.e. anxiety and depression) and disease-related parenting stress were also significantly correlated with lower HRQOL. Examination of possible mediator models via a series of regression analyses confirmed that disease-related parenting stress served as a mediator between pain frequency and physical and psychosocial HRQOL. Less consistent were findings for mediation models involving internalizing symptoms. For these, parent-rated teen depression and teen anxiety served as mediators of the association of pain frequency and HRQOL.</p> <p>Conclusion</p> <p>Results are consistent with extant literature that suggests the association of pain and HRQOL and identify concomitant pain variables of internalizing symptoms and family variables as mediators. Efforts to improve HRQOL should aim to address internalizing symptoms associated with pain as well as parenting stress in the context of SCD management.</p

In the face of climate change and exhaustive exercise: the physiological response of an important recreational fish species

Cobia (Rachycentron canadum) support recreational fisheries along the US mid- and south-Atlantic states and have been recently subjected to increased fishing effort, primarily during their spawning season in coastal habitats where increasing temperatures and expanding hypoxic zones are occurring due to climate change. We therefore undertook a study to quantify the physiological abilities of cobia to withstand increases in temperature and hypoxia, including their ability to recover from exhaustive exercise. Respirometry was conducted on cobia from Chesapeake Bay to determine aerobic scope, critical oxygen saturation, ventilation volume and the time to recover from exhaustive exercise under temperature and oxygen conditions projected to be more common in inshore areas by the middle and end of this century. Cobia physiologically tolerated predicted mid- and end-of-century temperatures (28–32°C) and oxygen concentrations as low as 1.7–2.4 mg l−1. Our results indicated cobia can withstand environmental fluctuations that occur in coastal habitats and the broad environmental conditions their prey items can tolerate. However, at these high temperatures, some cobia did suffer post-exercise mortality. It appears cobia will be able to withstand near-future climate impacts in coastal habitats like Chesapeake Bay, but as conditions worsen, catch-and-release fishing may result in higher mortality than under present conditions

Early exposure of bay scallops (Argopecten irradians) to high CO2 causes a decrease in larval shell growth

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS ONE 8 (2013): e61065, doi:10.1371/journal.pone.0061065.Ocean acidification, characterized by elevated pCO2 and the associated decreases in seawater pH and calcium carbonate saturation state (Ω), has a variable impact on the growth and survival of marine invertebrates. Larval stages are thought to be particularly vulnerable to environmental stressors, and negative impacts of ocean acidification have been seen on fertilization as well as on embryonic, larval, and juvenile development and growth of bivalve molluscs. We investigated the effects of high CO2 exposure (resulting in pH = 7.39, Ωar = 0.74) on the larvae of the bay scallop Argopecten irradians from 12 h to 7 d old, including a switch from high CO2 to ambient CO2 conditions (pH = 7.93, Ωar = 2.26) after 3 d, to assess the possibility of persistent effects of early exposure. The survival of larvae in the high CO2 treatment was consistently lower than the survival of larvae in ambient conditions, and was already significantly lower at 1 d. Likewise, the shell length of larvae in the high CO2 treatment was significantly smaller than larvae in the ambient conditions throughout the experiment and by 7 d, was reduced by 11.5%. This study also demonstrates that the size effects of short-term exposure to high CO2 are still detectable after 7 d of larval development; the shells of larvae exposed to high CO2 for the first 3 d of development and subsequently exposed to ambient CO2 were not significantly different in size at 3 and 7 d than the shells of larvae exposed to high CO2 throughout the experiment.This work was funded by a Woods Hole Oceanographic Institution Interdisciplinary Award to Mullineaux & McCorkle; and awards to Mullineaux & White, to McCorkle, and to Cohen & McCorkle through NOAA (National Oceanic and Admosphereic Administration) Sea Grant #NA10OAR4170083. White was funded through a National Defense Science and Engineering Graduate Fellowship through the American Society for Engineering Education

The Effects of daily diabetina tea consumption on glycosylated hemoglobin, fasting glucose and lipid levels, and body mass index in normoglycemic individuals

Type 2 diabetes mellitus is a chronic disease responsible for high levels of morbidity and mortality in the United States, especially among some ethnic minority populations. Diabetina tea, a commercially-available herbal blend tea, is a well known herbal remedy for high blood sugar among Hispanic American diabetics. This study will examine the effect of twice-daily unsweetened Diabetina tea consumption over an 8 week period on glucose (sugar) and lipid (fat) metabolism. Potential effects of Diabetina tea consumption on glucose metabolism will be measured by glycosylated hemoglobin (HbA1c) and fasting glucose tests, while the potential effects of Diabetina tea consumption on lipid metabolism will be measured by fasting blood lipid levels, in addition to body mass index (BMI) and waist circumference (WC) measurements

Scaling Relations of Spiral Galaxies

We construct a large data set of global structural parameters for 1300 field and cluster spiral galaxies and explore the joint distribution of luminosity L, optical rotation velocity V, and disk size R at I- and 2MASS K-bands. The I- and K-band velocity-luminosity (VL) relations have log-slopes of 0.29 and 0.27, respectively with sigma_ln(VL)~0.13, and show a small dependence on color and morphological type in the sense that redder, early-type disk galaxies rotate faster than bluer, later-type disk galaxies for most luminosities. The VL relation at I- and K-bands is independent of surface brightness, size and light concentration. The log-slope of the I- and K-band RL relations is a strong function of morphology and varies from 0.25 to 0.5. The average dispersion sigma_ln(RL) decreases from 0.33 at I-band to 0.29 at K, likely due to the 2MASS selection bias against lower surface brightness galaxies. Measurement uncertainties are sigma_ln(V)~0.09, sigma_ln(L)~0.14 and somewhat larger and harder to estimate for ln(R). The color dependence of the VL relation is consistent with expectations from stellar population synthesis models. The VL and RL residuals are largely uncorrelated with each other; the RV-RL residuals show only a weak positive correlation. These correlations suggest that scatter in luminosity is not a significant source of the scatter in the VL and RL relations. The observed scaling relations can be understood in the context of a model of disk galaxies embedded in dark matter halos that invokes low mean spin parameters and dark halo expansion, as we describe in our companion paper (Dutton et al. 2007). We discuss in two appendices various pitfalls of standard analytical derivations of galaxy scaling relations, including the Tully-Fisher relation with different slopes. (Abridged).Comment: Accepted for publication at ApJ. The full document, with high-resolution B&W and colour figures, is available at http://www.astro.queensu.ca/~courteau/papers/VRL2007ApJ.pdf . Our data base for 1303 spiral galaxies is also available at http://www.astro.queensu.ca/~courteau/data/VRL2007.da

An expeditious green route toward 2-aryl-4- phenyl-1H-imidazoles

Background: Azaheterocycles are an important class of compounds because of their highly potent medicinal activities, and the imidazole subcategory is of special interest in regard to drug discovery research. Findings: An expeditious synthetic protocol of 2-aryl-4-phenyl-1H-imidazoles has been accomplished by reacting phenylglyoxal monohydrate, ammonium acetate, and aldehyde under sonication. Following this green approach a series of 2-aryl-4-phenyl-1H-imidazoles has been synthesized using diversely substituted aldehydes. Conclusions: A rapid and simple synthetic procedure to synthesize diversely substituted 2-aryl-4-phenyl-1H-imidazoles has been reported. Other salient features of this protocol include milder conditions, atom-economy, easy extraction, and minimum wastes. The present procedure may find application in the synthesis of biologically active molecules

Seeing double with K2: Testing re-inflation with two remarkably similar planets around red giant branch stars

Despite more than 20 years since the discovery of the first gas giant planet with an anomalously large radius, the mechanism for planet inflation remains unknown. Here, we report the discovery of EPIC228754001.01, an inflated gas giant planet found with the NASA K2 Mission, and a revised mass for another inflated planet, K2-97b. These planets reside on ~9 day orbits around host stars which recently evolved into red giants. We constrain the irradiation history of these planets using models constrained by asteroseismology and Keck/HIRES spectroscopy and radial velocity measurements. We measure planet radii of 1.31 +\- 0.11 Rjup and and 1.30 +\- 0.07 Rjup, respectively. These radii are typical for planets receiving the current irradiation, but not the former, zero age main sequence irradiation of these planets. This suggests that the current sizes of these planets are directly correlated to their current irradiation. Our precise constraints of the masses and radii of the stars and planets in these systems allow us to constrain the planetary heating efficiency of both systems as 0.03% +0.03%/-0.02%. These results are consistent with a planet re-inflation scenario, but suggest the efficiency of planet re-inflation may be lower than previously theorized. Finally, we discuss the agreement within 10% of stellar masses and radii, and planet masses, radii, and orbital periods of both systems and speculate that this may be due to selection bias in searching for planets around evolved stars.Comment: 18 pages, 15 figures, accepted to AJ. Figures 11, 12, and 13 are the key figures of the pape

A new variance ratio metric to detect the timescale of compensatory dynamics

Understanding the mechanisms governing ecological stability—why a property such as primary productivity is stable in some communities and variable in others—has long been a focus of ecology. Compensatory dynamics, in which anti-synchronous fluctuations between populations buffer against fluctuations at the community level, are a key theoretical mechanism of stability. Classically, compensatory dynamics have been quantified using a variance ratio approach that compares the ratio between community variance and aggregate population variance, such that a lower ratio indicates compensation and a higher ratio indicates synchrony among species fluctuations. However, population dynamics may be influenced by different drivers that operate on different timescales, and evidence from aquatic systems indicates that communities can be compensatory on some timescales and synchronous on others. The variance ratio and related metrics cannot reflect this timescale specificity, yet have remained popular, especially in terrestrial systems. Here, we develop a timescale-specific variance ratio approach that formally decomposes the classical variance ratio according to the timescales of distinct contributions. The approach is implemented in a new R package, called tsvr, that accompanies this paper. We apply our approach to a long-term, multisite grassland community dataset. Our approach demonstrates that the degree of compensation vs. synchrony in community dynamics can vary by timescale. Across sites, population variability was typically greater over longer compared to shorter timescales. At some sites, minimal timescale specificity in compensatory dynamics translated this pattern of population variability into a similar pattern of greater community variability on longer compared to shorter timescales. But at other sites, differentially stronger compensatory dynamics at longer compared to shorter timescales produced lower-than-expected community variability on longer timescales. Within every site, there were plots that exhibited shifts in the strength of compensation between timescales. Our results highlight that compensatory vs. synchronous dynamics are intrinsically timescale-dependent concepts, and our timescale-specific variance ratio provides a metric to quantify timescale specificity and relate it back to the classic variance ratio