12,330 research outputs found
A model balancing cooperation and competition explains our right-handed world and the dominance of left-handed athletes
An overwhelming majority of humans are right-handed. Numerous explanations
for individual handedness have been proposed, but this population-level
handedness remains puzzling. Here we use a minimal mathematical model to
explain this population-level hand preference as an evolved balance between
cooperative and competitive pressures in human evolutionary history. We use
selection of elite athletes as a test-bed for our evolutionary model and
account for the surprising distribution of handedness in many professional
sports. Our model predicts strong lateralization in social species with limited
combative interaction, and elucidates the rarity of compelling evidence for
"pawedness" in the animal world.Comment: 5 pages of text and 3 figures in manuscript, 8 pages of text and two
figures in supplementary materia
β-arrestin regulates estradiol membrane-initiated signaling in hypothalamic neurons.
Estradiol (E2) action in the nervous system is the result of both direct nuclear and membrane-initiated signaling (EMS). E2 regulates membrane estrogen receptor-α (ERα) levels through opposing mechanisms of EMS-mediated trafficking and internalization. While ß-arrestin-mediated mERα internalization has been described in the cortex, a role of ß-arrestin in EMS, which underlies multiple physiological processes, remains undefined. In the arcuate nucleus of the hypothalamus (ARH), membrane-initiated E2 signaling modulates lordosis behavior, a measure of female sexually receptivity. To better understand EMS and regulation of ERα membrane levels, we examined the role of ß-arrestin, a molecule associated with internalization following agonist stimulation. In the present study, we used an immortalized neuronal cell line derived from embryonic hypothalamic neurons, the N-38 line, to examine whether ß-arrestins mediate internalization of mERα. β-arrestin-1 (Arrb1) was found in the ARH and in N-38 neurons. In vitro, E2 increased trafficking and internalization of full-length ERα and ERαΔ4, an alternatively spliced isoform of ERα, which predominates in the membrane. Treatment with E2 also increased phosphorylation of extracellular-signal regulated kinases 1/2 (ERK1/2) in N-38 neurons. Arrb1 siRNA knockdown prevented E2-induced ERαΔ4 internalization and ERK1/2 phosphorylation. In vivo, microinfusions of Arrb1 antisense oligodeoxynucleotides (ODN) into female rat ARH knocked down Arrb1 and prevented estradiol benzoate-induced lordosis behavior compared with nonsense scrambled ODN (lordosis quotient: 3 ± 2.1 vs. 85.0 ± 6.0; p < 0.0001). These results indicate a role for Arrb1 in both EMS and internalization of mERα, which are required for the E2-induction of female sexual receptivity
The influence of societal individualism on a century of tobacco use: modelling the prevalence of smoking
Smoking of tobacco is predicted to cause approximately six million deaths
worldwide in 2014. Responding effectively to this epidemic requires a thorough
understanding of how smoking behaviour is transmitted and modified. Here, we
present a new mathematical model of the social dynamics that cause cigarette
smoking to spread in a population. Our model predicts that more individualistic
societies will show faster adoption and cessation of smoking. Evidence from a
new century-long composite data set on smoking prevalence in 25 countries
supports the model, with direct implications for public health interventions
around the world. Our results suggest that differences in culture between
societies can measurably affect the temporal dynamics of a social spreading
process, and that these effects can be understood via a quantitative
mathematical model matched to observations
Mechanisms for Lasing with Cold Atoms as the Gain Medium
We realize a laser with a cloud of cold rubidium atoms as gain medium, placed
in a low-finesse cavity. Three different regimes of laser emission are observed
corresponding respectively to Mollow, Raman and Four Wave Mixing mechanisms. We
measure an output power of up to 300 W and present the main properties of
these different lasers in each regime
Biological Control Agents in Integrated Pest Management: Are They Regulated - A Research Guide
Integrated Pest Management (IPM) is a method of coordinating different pest control techniques which balance environmental, economic, and social issues with the traditional use of chemical pesticides. The author predicts expanding implementation of biological control methods of IPM in light of the environmental harm and expense that results from the use of chemical pesticides. This guide to legal and nonlegal resources focuses on research in the area of biological control methods of IPM, and the means of obtaining current information on this topic
Better Strategies to Fight Workplace Sexual Harassment In New Jersey: Why the Title VII Affirmative Defense Should Apply to the Law Against Discrimination
An Investigation of College Students\u27 Attitudes Towards Immigration to the United States
This survey-based thesis examines correlations among different demographic groups (race, religiosity, political orientation, and gender) and their feelings about immigrants and immigration to the United States. The sample consisted of 79 undergraduate students at the University of Vermont. Respondents to the survey answered these four demographic questions as well as six attitudinal questions about immigrants and immigration. My findings suggest a relationship between very liberal respondents, non-binary / a third gender / or other respondents, and respondents who rarely or never attended religious services growing up, and more liberal or pro immigrant ideology. Because non-white respondents comprised a very small portion of the sample size, it is not possible to make inferences about the effects of race on attitudes. These results indicate that specific identities may inform opinions about immigration
Commutator Leavitt path algebras
For any field K and directed graph E, we completely describe the elements of
the Leavitt path algebra L_K(E) which lie in the commutator subspace
[L_K(E),L_K(E)]. We then use this result to classify all Leavitt path algebras
L_K(E) that satisfy L_K(E)=[L_K(E),L_K(E)]. We also show that these Leavitt
path algebras have the additional (unusual) property that all their Lie ideals
are (ring-theoretic) ideals, and construct examples of such rings with various
ideal structures.Comment: 24 page
Modelling the cost effectiveness of interferon beta and glatiramer acetate in the management of multiple sclerosis
OBJECTIVE: To evaluate the cost effectiveness of four disease modifying treatments (interferon betas and glatiramer acetate) for relapsing remitting and secondary progressive multiple sclerosis in the United Kingdom. DESIGN: Modelling cost effectiveness. SETTING: UK NHS. PARTICIPANTS: Patients with relapsing remitting multiple sclerosis and secondary progressive multiple sclerosis. MAIN OUTCOME MEASURES: Cost per quality adjusted life year gained. RESULTS: The base case cost per quality adjusted life year gained by using any of the four treatments ranged from £42 000 ($66 469; 61 630) to £98 000 based on efficacy information in the public domain. Uncertainty analysis suggests that the probability of any of these treatments having a cost effectiveness better than £20 000 at 20 years is below 20%. The key determinants of cost effectiveness were the time horizon, the progression of patients after stopping treatment, differential discount rates, and the price of the treatments. CONCLUSIONS: Cost effectiveness varied markedly between the interventions. Uncertainty around point estimates was substantial. This uncertainty could be reduced by conducting research on the true magnitude of the effect of these drugs, the progression of patients after stopping treatment, the costs of care, and the quality of life of the patients. Price was the key modifiable determinant of the cost effectiveness of these treatments
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