4,467 research outputs found
Cancelled - Berkeley\u27s A Priori Argument for God\u27s Exstence
Berkeley’s appeal to a posteriori arguments for God’s existence supports belief only in a God who is finite. But by appealing to an a priori argument for God’s existence, Berkeley emphasizes God’s infinity. In this latter argument, God is not the efficient cause of particular finite things in the world, for such an explanation does not provide a justification or rationale for why the totality of finite things would exist in the first place. Instead, God is understood as the creator of the total unity of all there is, the whole of creation. In this a priori argument, we should not focus on the specific objects that God creates, for that requires that we think that God knows each finite thing as distinct from every other. Rather, we should recognize how God creates all things in creating the complex, infinite totality of finite perceivings, each of which exists in virtue of the distinctions and relations it expresses
Unique thermal behavior of sphingomyelin species with nonhydroxy and 2-hydroxy very-long-chain (C28-C32) PUFAs
In rat germ cells and spermatozoa, sphingomyelin (SM) contains molecular species with nonhydroxy (n) and 2-hydroxy (h) very-long-chain polyunsaturated fatty acids (V), the most abundant being SMs with (n- and h-) 28:4n-6, 30:5n-6, and 32:5n-6 as acyl chains. The aim of this study was to gain information about their thermotropic behavior and interactions with other lipids. After isolation from rat testis, multilamellar and giant unilamellar vesicles from these SMs were examined using fluorescent probes. Only n-32:5 SM and h-32:5 SM displayed a gel-liquid transition temperature (Tt ≈ 21?22°C), the rest remaining in the liquid state in the 5°C?45°C range. The degree of order was larger in bilayers of any of the h-V SMs than in those of their chain-matched n-V SMs. Both, but n-V SM relatively more than h-V SM, decreased the Tt of dimyristoylphosphatidylcholine as their proportion increased in binary phosphatidylcholine:SM liposomes. In contrast to the established ability of 16:0 SM to form lateral cholesterol/SM-rich ordered domains in ternary dioleoylphosphatidylcholine:cholesterol:SM bilayers, neither n-V SM nor h-V SM showed a tendency to do so. Thus, these SMs are in the fluid state and are not involved in this type of domains in spermatozoa at physiological temperatures. However, this state could be altered at the very low temperatures at which these gametes are usually preserved.Fil: Peñalva, Daniel Alejandro. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); ArgentinaFil: Furland, Natalia Edith. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); ArgentinaFil: Lopez, Gustavo H.. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia; ArgentinaFil: Aveldaño, Marta Isabel. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); ArgentinaFil: Antollini, Silvia Susana. Consejo Nacional de Investigaciones Cientificas y Técnicas. Centro Científico Tecnológico Bahia Blanca. Instituto de Investigaciones Bioquímicas Bahia Blanca (i); Argentin
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
Recommended from our members
Electrophysiological Guidance of Epidural Electrode Array Implantation over the Human Lumbosacral Spinal Cord to Enable Motor Function after Chronic Paralysis.
Epidural electrical stimulation (EES) of the spinal cord has been shown to restore function after spinal cord injury (SCI). Characterization of EES-evoked motor responses has provided a basic understanding of spinal sensorimotor network activity related to EES-enabled motor activity of the lower extremities. However, the use of EES-evoked motor responses to guide EES system implantation over the spinal cord and their relation to post-operative EES-enabled function in humans with chronic paralysis attributed to SCI has yet to be described. Herein, we describe the surgical and intraoperative electrophysiological approach used, followed by initial EES-enabled results observed in 2 human subjects with motor complete paralysis who were enrolled in a clinical trial investigating the use of EES to enable motor functions after SCI. The 16-contact electrode array was initially positioned under fluoroscopic guidance. Then, EES-evoked motor responses were recorded from select leg muscles and displayed in real time to determine electrode array proximity to spinal cord regions associated with motor activity of the lower extremities. Acceptable array positioning was determined based on achievement of selective proximal or distal leg muscle activity, as well as bilateral muscle activation. Motor response latencies were not significantly different between intraoperative recordings and post-operative recordings, indicating that array positioning remained stable. Additionally, EES enabled intentional control of step-like activity in both subjects within the first 5 days of testing. These results suggest that the use of EES-evoked motor responses may guide intraoperative positioning of epidural electrodes to target spinal cord circuitry to enable motor functions after SCI
Formation of Super-Earths
Super-Earths are the most abundant planets known to date and are
characterized by having sizes between that of Earth and Neptune, typical
orbital periods of less than 100 days and gaseous envelopes that are often
massive enough to significantly contribute to the planet's overall radius.
Furthermore, super-Earths regularly appear in tightly-packed multiple-planet
systems, but resonant configurations in such systems are rare. This chapters
summarizes current super-Earth formation theories. It starts from the formation
of rocky cores and subsequent accretion of gaseous envelopes. We follow the
thermal evolution of newly formed super-Earths and discuss their atmospheric
mass loss due to disk dispersal, photoevaporation, core-cooling and collisions.
We conclude with a comparison of observations and theoretical predictions,
highlighting that even super-Earths that appear as barren rocky cores today
likely formed with primordial hydrogen and helium envelopes and discuss some
paths forward for the future.Comment: Invited review accepted for publication in the 'Handbook of
Exoplanets,' Planet Formation section, Springer Reference Works, Juan Antonio
Belmonte and Hans Deeg, Ed
Psychological symptoms, mental fatigue and behavioural adherence after 72 continuous days of strict lockdown during the COVID-19 pandemic in Argentina
Background An early and prolonged lockdown was adopted in Argentina during the first wave of COVID-19. Early reports evidenced elevated psychological symptoms. Aims To explore if the prolonged lockdown was associated with elevated anxiety and depressive symptoms; if mental fatigue was associated with lockdown adherence (a phenomenon called ‘behavioural fatigue’); and if financial concerns were associated with lockdown adherence and emotional symptoms. Method The survey included standardised questionnaires to assess depressive (PHQ-9) and anxious (GAD-7) symptoms, mental fatigue, risk perception, lockdown adherence, financial concerns, daily stress, loneliness, intolerance to uncertainty, negative repetitive thinking and cognitive problems. LASSO regression analyses were carried out to predict depression, anxiety and lockdown adherence Results The survey reached 3617 adults (85.2% female) from all provinces of Argentina after 72 days of lockdown. Data were collected between 21 May 2020 and 4 June 2020. In that period, Argentina had an Oxford stringency index of 85/100. Of those surveyed, 45.6% and 27% met the cut-offs for depression and anxiety, respectively. Mental fatigue, cognitive failures and financial concerns were correlated with psychological symptoms, but not with adherence to lockdown. In regression models, mental fatigue, cognitive failures and loneliness were the most important variables to predict depression, intolerance to uncertainty and lockdown difficulty were the most important for anxiety, and perceived threat was the most important for predicting lockdown adherence. Conclusions During the extended lockdown, psychological symptoms increased, being enhanced by mental fatigue, cognitive difficulties and financial concerns. We found no evidence of behavioural fatigue. Thus, feeling mentally fatigued is not the same as being behaviourally fatigued.Fil: Torrente, Fernando Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Yoris Magnago, Adrián Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Low, Daniel Mark. Harvard Medical School; Estados Unidos. Massachusetts Institute of Technology; Estados UnidosFil: Lopez, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Bekinschtein, Pedro Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Vázquez, Gustavo H.. Queen's University Medical School; CanadáFil: Manes, Facundo Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Cetkovich Bakmas, Marcelo Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; Argentin
The IR Luminosity Functions of Rich Clusters
We present MIPS observations of the cluster A3266. About 100 spectroscopic
cluster members have been detected at 24 micron. The IR luminosity function in
A3266 is very similar to that in the Coma cluster down to the detection limit
L_IR~10^43 ergs/s, suggesting a universal form of the bright end IR LF for
local rich clusters with M~10^15 M_sun. The shape of the bright end of the
A3266-Coma composite IR LF is not significantly different from that of nearby
field galaxies, but the fraction of IR-bright galaxies (SFR > 0.2M_sun/yr) in
both clusters increases with cluster-centric radius. The decrease of the blue
galaxy fraction toward the high density cores only accounts for part of the
trend; the fraction of red galaxies with moderate SFRs (0.2 < SFR < 1 M_sun/yr)
also decreases with increasing galaxy density. These results suggest that for
the IR bright galaxies, nearby rich clusters are distinguished from the field
by a lower star-forming galaxy fraction, but not by a change in L*_IR. The
composite IR LF of Coma and A3266 shows strong evolution when compared with the
composite IR LF of two z~0.8 clusters, MS 1054 and RX J0152, with L*_IR \propto
(1+z)^{3.2+/-0.7},Phi*_IR \propto (1+z)^{1.7+/-1.0}. This L*_IR evolution is
indistinguishable from that in the field, and the Phi*_IR evolution is
stronger, but still consistent with that in the field. The similarity of the
evolution of bright-end IR LF in very different cluster and field environments
suggests either this evolution is driven by the mechanism that works in both
environments, or clusters continually replenish their star-forming galaxies
from the field, yielding an evolution in the IR LF that is similar to the
field. The mass-normalized integrated star formation rates (SFRs) of clusters
within 0.5R_200 also evolve strongly with redshift, as (1+z)^5.3.Comment: 15 pages, 8 figures, 1 table, accepted by Ap
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