577 research outputs found
Divine simplicity as actus purus
This thesis presents a case for the traditional doctrine of divine simplicity by
construing it along the lines that God exists as actus purus. My formulation of divine
simplicity draws upon the medieval insight that God is what He is in virtue of what He
does in one, eternal act of will with which He is identical.
In chapter I, I survey the contemporary literature on divine simplicity. In chapter
II, I critique Alvin Plantinga??s Platonic theory of the divine attributes as formulated in
Does God Have a Nature? I contend it brings with it the cost of abandoning the doctrine
of God??s aseity, as well as a problematic understanding of the very notion of what it
means to claim that God has a particular property. In chapter III, I provide rejoinders to
all of Plantinga??s defeaters against divine simplicity. I argue that by understanding the
origin of God??s attributes to be the result of what He does, Plantinga??s two major
criticisms against divine simplicity fail.
In chapter IV, I develop a viable theory of divine simplicity, given an actus purus
conception of God, and I formulate a number of arguments supporting it. By drawing
upon the resources of action theory, I clarify, in detail, what exactly it means to claim
that God is identical with His act of will. And I demonstrate the fruitfulness of an actus
purus construal of divine simplicity by showing how it solves a large number of
problems that theists face.In the last chapter, I note some of the difficulties with my position due to its
commitment to an eternal God, and I suggest some of the ways that these problems can
be overcome. However, in addition to showing the difficulties that face my position, I
also demonstrate the rich number of implications that follow from it. As such, I seek to
demonstrate that the traditional understanding of the divine essence is something that is
worthy for theists to embrace and to explore, because it is full of truth and wisdom that
deserves to be preserved for later generations to celebrate and enjoy
Genetic and biochemical analyses of chromosome and plasmid gene homologues encoding ICL and ArCP domains in Vibrioanguillarum strain 775
Anguibactin, the siderophore produced by Vibrio anguillarum 775 is synthesized from 2,3-dihydroxybenzoic acid (DHBA), cysteine and hydroxyhistamine via a nonribosomal peptide synthetase (NRPS) mechanism. Most of the genes encoding anguibactin biosynthetic proteins are harbored by the pJM1 plasmid. In this work we report the identification of a homologue of the plasmid-encoded angB on the chromosome of strain 775. The product of both genes harbor an isochorismate lyase (ICL) domain that converts isochorismic acid to 2,3-dihydro-2,3-dihydroxybenzoic acid, one of the steps of DHBA synthesis. We show in this work that both ICL domains are functional in the production of DHBA in V. anguillarum as well as in E. coli. Substitution by alanine of the aspartic acid residue in the active site of both ICL domains completely abolishes their isochorismate lyase activity in vivo. The two proteins also carry an aryl carrier protein (ArCP) domain. In contrast with the ICL domains only the plasmid encoded ArCP can participate in anguibactin production as determined by complementation analyses and site-directed mutagenesis in the active site of the plasmid encoded protein, S248A. The site-directed mutants, D37A in the ICL domain and S248A in the ArCP domain of the plasmid encoded AngB were also tested in vitro and clearly show the importance of each residue for the domain function and that each domain operates independently.
On the abundance of non-cometary HCN on Jupiter
Using one-dimensional thermochemical/photochemical kinetics and transport
models, we examine the chemistry of nitrogen-bearing species in the Jovian
troposphere in an attempt to explain the low observational upper limit for HCN.
We track the dominant mechanisms for interconversion of N2-NH3 and HCN-NH3 in
the deep, hightemperature troposphere and predict the rate-limiting step for
the quenching of HCN at cooler tropospheric altitudes. Consistent with other
investigations that were based solely on time-scale arguments, our models
suggest that transport-induced quenching of thermochemically derived HCN leads
to very small predicted mole fractions of hydrogen cyanide in Jupiter's upper
troposphere. By the same token, photochemical production of HCN is ineffective
in Jupiter's troposphere: CH4-NH3 coupling is inhibited by the physical
separation of the CH4 photolysis region in the upper stratosphere from the NH3
photolysis and condensation region in the troposphere, and C2H2-NH3 coupling is
inhibited by the low tropospheric abundance of C2H2. The upper limits from
infrared and submillimeter observations can be used to place constraints on the
production of HCN and other species from lightning and thundershock sources.Comment: 56 pages, 0 tables, 6 figures. Submitted to Faraday Discussions [in
press
Collision Mortality Has No Discernible Effect on Population Trends of North American Birds
Avian biodiversity is threatened by numerous anthropogenic factors and migratory species are especially at risk. Migrating birds frequently collide with manmade structures and such losses are believed to represent the majority of anthropogenic mortality for North American birds. However, estimates of total collision mortality range across several orders of magnitude and effects on population dynamics remain unknown. Herein, we develop a novel method to assess relative vulnerability to anthropogenic threats, which we demonstrate using 243,103 collision records from 188 species of eastern North American landbirds. After correcting mortality estimates for variation attributable to population size and geographic overlap with potential collision structures, we found that per capita vulnerability to collision with buildings and towers varied over more than four orders of magnitude among species. Species that migrate long distances or at night were much more likely to be killed by collisions than year-round residents or diurnal migrants. However, there was no correlation between relative collision mortality and long-term population trends for these same species. Thus, although millions of North American birds are killed annually by collisions with manmade structures, this source of mortality has no discernible effect on populations
Dopamine transporter (DAT1) and dopamine receptor D4 (DRD4) genotypes differentially impact on electrophysiological correlates of error processing
Peer reviewedPublisher PD
Variability and Predictors of Urinary Bisphenol A Concentrations during Pregnancy
BackgroundPrenatal bisphenol A (BPA) exposure may be associated with developmental toxicity, but few studies have examined the variability and predictors of urinary BPA concentrations during pregnancy.ObjectiveOur goal was to estimate the variability and predictors of serial urinary BPA concentrations taken during pregnancy.MethodsWe measured BPA concentrations during pregnancy and at birth in three spot urine samples from 389 women. We calculated the intraclass correlation coefficient (ICC) to assess BPA variability and estimated associations between log10-transformed urinary BPA concentrations and demographic, occupational, dietary, and environmental factors, using mixed models.ResultsGeometric mean (GM) creatinine-standardized concentrations (micrograms per gram) were 1.7 (16 weeks), 2.0 (26 weeks), and 2.0 (birth). Creatinine-standardized BPA concentrations exhibited low reproducibility (ICC = 0.11). By occupation, cashiers had the highest BPA concentrations (GM: 2.8 μg/g). Consuming canned vegetables at least once a day was associated with higher BPA concentrations (GM = 2.3 μg/g) compared with those consuming no canned vegetables (GM = 1.6 μg/g). BPA concentrations did not vary by consumption of fresh fruits and vegetables, canned fruit, or store-bought fresh and frozen fish. Urinary high-molecular-weight phthalate and serum tobacco smoke metabolite concentrations were positively associated with BPA concentrations.ConclusionsThese results suggest numerous sources of BPA exposure during pregnancy. Etiological studies may need to measure urinary BPA concentrations more than once during pregnancy and adjust for phthalates and tobacco smoke exposures
Altered Error Processing following Vascular Thalamic Damage: Evidence from an Antisaccade Task
Event-related potentials (ERP) research has identified a negative deflection within about 100 to 150 ms after an erroneous response – the error-related negativity (ERN) - as a correlate of awareness-independent error processing. The short latency suggests an internal error monitoring system acting rapidly based on central information such as an efference copy signal. Studies on monkeys and humans have identified the thalamus as an important relay station for efference copy signals of ongoing saccades. The present study investigated error processing on an antisaccade task with ERPs in six patients with focal vascular damage to the thalamus and 28 control subjects. ERN amplitudes were significantly reduced in the patients, with the strongest ERN attenuation being observed in two patients with right mediodorsal and ventrolateral and bilateral ventrolateral damage, respectively. Although the number of errors was significantly higher in the thalamic lesion patients, the degree of ERN attenuation did not correlate with the error rate in the patients. The present data underline the role of the thalamus for the online monitoring of saccadic eye movements, albeit not providing unequivocal evidence in favour of an exclusive role of a particular thalamic site being involved in performance monitoring. By relaying saccade-related efference copy signals, the thalamus appears to enable fast error processing. Furthermore early error processing based on internal information may contribute to error awareness which was reduced in the patients
A descriptive analysis of relations between parents' self-reported smoking behavior and infants' daily exposure to environmental tobacco smoke
<p>Abstract</p> <p>Background</p> <p>The aims of the present study were to examine relations between parents' self-reported smoking behavior and infants' daily exposure to environmental tobacco smoke, as assessed by urinary cotinine-to-creatinine ratio (CCR), and to describe the CCR over seven days among infants at home.</p> <p>Methods</p> <p>A convenience sample of 27 households was drawn. Each household had to have at least one daily tobacco smoker and one child up to three years of age. Over a seven-day period, urine samples were obtained from the child daily. To examine relations between parents' self-reported smoking and infants' daily CCR, generalized estimating equation (GEE) analysis was used.</p> <p>Results</p> <p>The data revealed that infants from households with indoor smoking had higher CCRs than infants in households with outdoor smoking. CCRs were higher in girls than in boys. Older infants had lower CCRs than younger infants. Smoking outside the home versus inside the home, infant's gender, and infants' age accounted for 68% of the variance in CCR in a GEE data analysis model. No increase or decrease of CCR over time was found.</p> <p>Conclusion</p> <p>The findings suggest that parents' self-reported smoking indoors at home versus outdoors is predictive of CCR among infants three and younger. Higher CCR concentrations in girls' urine need further examination. Furthermore, significant fluctuations in daily CCR were not apparent in infants over a seven-day time period.</p
Electrophysiological evidence of enhanced performance monitoring in recently abstinent alcoholic men
RATIONALE: Chronic alcoholism is associated with mild to moderate cognitive impairment. Under certain conditions, impairment can be ameliorated by invoking compensatory processes. OBJECTIVE: To identify electrophysiological mechanisms of such compensation that would be required to resolve response conflict. METHODS: 14 abstinent alcoholic men and 14 similarly aged control men performed a variation of the Eriksen flanker task during an electroencephalography (EEG) recording to examine whether alcoholics could achieve and maintain control-level performance and whether EEG markers could identify evidence for the action of compensatory processes in the alcoholics. Monitoring processes engaged following a response were indexed by the correct related negativity (CRN) and error related negativity (ERN), two medial-frontal negative event-related potentials. RESULTS: The alcoholics were able to perform at control levels on accuracy and reaction time (RT). Alcoholics generated larger ERN amplitudes following incorrect responses and larger CRNs following correct responses than controls. Both groups showed evidence of post-error slowing. Larger CRN amplitudes in the alcoholics were related to longer RTs. Also observed in the alcoholics was an association between smaller CRN amplitudes and length of sobriety, suggesting a normalization of monitoring activity with extended abstinence. CONCLUSIONS: To the extent that greater amplitude of these electrophysiological markers of performance monitoring indexes greater resource allocation and performance compensation, the larger amplitudes observed in the alcoholic than control group support the view that elevated performance monitoring enables abstinent alcoholics to overcome response conflict, as was evident in their control-level performance
Embodied Emotion Modulates Neural Signature of Performance Monitoring
BACKGROUND:Recent research on the "embodiment of emotion" implies that experiencing an emotion may involve perceptual, somatovisceral, and motor feedback aspects. For example, manipulations of facial expression and posture appear to induce emotional states and influence how affective information is processed. The present study investigates whether performance monitoring, a cognitive process known to be under heavy control of the dopaminergic system, is modulated by induced facial expressions. In particular, we focused on the error-related negativity, an electrophysiological correlate of performance monitoring. METHODS/PRINCIPAL FINDINGS:During a choice reaction task, participants held a Chinese chop stick either horizontally between the teeth ("smile" condition) or, in different runs, vertically ("no smile") with the upper lip. In a third control condition, no chop stick was used ("no stick"). It could be shown on a separate sample that the facial feedback procedure is feasible to induce mild changes in positive affect. In the ERP sample, the smile condition, hypothesized to lead to an increase in dopaminergic activity, was associated with a decrease of ERN amplitude relative to "no smile" and "no stick" conditions. CONCLUSION:Embodying emotions by induced facial expressions leads to a changes in the neural correlates of error detection. We suggest that this is due to the joint influence of the dopaminergic system on positive affect and performance monitoring
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