Rotation and Spin in Physics

We delineate the role of rotation and spin in physics, discussing in order Newtonian classical physics, special relativity, quantum mechanics, quantum electrodynamics and general relativity. In the latter case, we discuss the generalization of the Kepler formula to post-Newtonian order $(c^{-2}$) including spin effects and two-body effects. Experiments which verify the theoretical results for general relativistic spin-orbit effects are discussed as well as efforts being made to verify the spin-spin effects

Complex-Distance Potential Theory and Hyperbolic Equations

An extension of potential theory in R^n is obtained by continuing the Euclidean distance function holomorphically to C^n. The resulting Newtonian potential is generated by an extended source distribution D(z) in C^n whose restriction to R^n is the delta function. This provides a natural model for extended particles in physics. In C^n, interpreted as complex spacetime, D(z) acts as a propagator generating solutions of the wave equation from their initial values. This gives a new connection between elliptic and hyperbolic equations that does not assume analyticity of the Cauchy data. Generalized to Clifford analysis, it induces a similar connection between solutions of elliptic and hyperbolic Dirac equations. There is a natural application to the time-dependent, inhomogeneous Dirac and Maxwell equations, and the `electromagnetic wavelets' introduced previously are an example.Comment: 25 pages, submited to Proceedings of 5th Intern. Conf. on Clifford Algebras, Ixtapa, June 24 - July 4, 199

An interferometric gravitational wave detector as a quantum-gravity apparatus

As a consequence of the extreme precision of the measurements it performs, an interferometric gravitational wave detector is a macroscopic apparatus for which quantum effects are not negligible. I observe that this property can be exploited to probe some aspects of the interplay between Quantum Mechanics and Gravity.Comment: LaTex, 7 pages. Version accepted for publication in Nature. Under press embargo until publicatio

Community ecology of the Middle Miocene primates of La Venta, Colombia: the relationship between ecological diversity, divergence time, and phylogenetic richness

It has been suggested that the degree of ecological diversity that characterizes a primate community correlates positively with both its phylogenetic richness and the time since the members of that community diverged (Fleagle and Reed in Primate communities. Cambridge University Press, New York, pp 92–115, 1999). It is therefore questionable whether or not a community with a relatively recent divergence time but high phylogenetic richness would be as ecologically variable as a community with similar phylogenetic richness but a more distant divergence time. To address this question, the ecological diversity of a fossil primate community from La Venta, Colombia, a Middle Miocene platyrrhine community with phylogenetic diversity comparable with extant platyrrhine communities but a relatively short time since divergence, was compared with that of modern Neotropical primate communities. Shearing quotients and molar lengths, which together are reliable indicators of diet, for both fossil and extant species were plotted against each other to describe the dietary “ecospace” occupied by each community. Community diversity was calculated as the area of the minimum convex polygon encompassing all community members. The diversity of the fossil community was then compared with that of extant communities to test whether the fossil community was less diverse than extant communities while taking phylogenetic richness into account. Results indicate that the La Ventan community was not significantly less ecologically diverse than modern communities, supporting the idea that ecological diversification occurred along with phylogenetic diversification early in platyrrhine evolution

Individual variation in levels of haptoglobin-related protein in children from Gabon

Background: Haptoglobin related protein (Hpr) is a key component of trypanosome lytic factors (TLF), a subset of highdensity lipoproteins (HDL) that form the first line of human defence against African trypanosomes. Hpr, like haptoglobin (Hp) can bind to hemoglobin (Hb) and it is the Hpr-Hb complexes which bind to these parasites allowing uptake of TLF. This unique form of innate immunity is primate-specific. To date, there have been no population studies of plasma levels of Hpr, particularly in relation to hemolysis and a high prevalence of ahaptoglobinemia as found in malaria endemic areas. Methods and Principal Findings: We developed a specific enzyme-linked immunosorbent assay to measure levels of plasma Hpr in Gabonese children sampled during a period of seasonal malaria transmission when acute phase responses (APR), malaria infection and associated hemolysis were prevalent. Median Hpr concentration was 0.28 mg/ml (range 0.03-1.1). This was 5-fold higher than that found in Caucasian children (0.049 mg/ml, range 0.002-0.26) with no evidence of an APR. A general linear model was used to investigate associations between Hpr levels, host polymorphisms, parasitological factors and the acute phase proteins, Hp, C-reactive protein (CRP) and albumin. Levels of Hpr were associated with Hp genotype, decreased with age and were higher in females. Hpr concentration was strongly correlated with that of Hp, but not CRP

Mindlessness Revisited: Sequential Request Techniques Foster Compliance by Draining Self-control Resources

The present research extends previous findings suggesting that sequential request techniques, such as the Foot-in-the-Door (FITD) or Door-in-the-Face (DITF) technique, are primarily effective under conditions conducive of mindlessness. We forward that this mindlessness may be the product of the influence technique itself. More specifically, based on the notion of self-control as a limited resource, we hypothesize that actively responding to the initial request-phase of a FITD-compliance gaining procedure drains the target of his/her self-regulatory resources, thus creating the mindlessness so often observed in social influence settings. This resource depletion opens the door for compliance with the target request. The results were in line with these expectations. More specifically, we observed that active responding to an initial request of a FITD technique reduced the availability of self-regulatory resources. This state of resource depletion mediated the effect of the technique on behavioral compliance. In addition, the results of this study ruled out the alternate explanation that the effects were attributable to mood or a general tendency for acquiescence

Human Labor Pain Is Influenced by the Voltage-Gated Potassium Channel KV6.4 Subunit.

By studying healthy women who do not request analgesia during their first delivery, we investigate genetic effects on labor pain. Such women have normal sensory and psychometric test results, except for significantly higher cuff pressure pain. We find an excess of heterozygotes carrying the rare allele of SNP rs140124801 in KCNG4. The rare variant KV6.4-Met419 has a dominant-negative effect and cannot modulate the voltage dependence of KV2.1 inactivation because it fails to traffic to the plasma membrane. In vivo, Kcng4 (KV6.4) expression occurs in 40% of retrograde-labeled mouse uterine sensory neurons, all of which express KV2.1, and over 90% express the nociceptor genes Trpv1 and Scn10a. In neurons overexpressing KV6.4-Met419, the voltage dependence of inactivation for KV2.1 is more depolarized compared with neurons overexpressing KV6.4. Finally, KV6.4-Met419-overexpressing neurons have a higher action potential threshold. We conclude that KV6.4 can influence human labor pain by modulating the excitability of uterine nociceptors.MCL, DKM, DW, and CGW acknowledge funding from Addenbrooke’s Charitable Trust and the NIHR Cambridge Biomedical Research Centre. MN was funded by the Wellcome Trust (200183/Z/15/Z); JH and ESS by a Rosetrees Postdoctoral Grant (A1296) and the BBSRC (BB/R006210/1); GC and ESS by Versus Arthritis Grants (RG21973); VBL and FR by the Wellcome Trust (106262/Z/14/Z and 106263/Z/14/Z) and a joint MRC programme within the Metabolic Diseases Unit (MRC_MC_UU_12012/3). EF, GI and CB were funded by the Cambridge NIHR Biomedical Research Centre Integrative Genomics theme and LAP by a BBSRC-funded studentship (BB/M011194/1)

Ethnic Variation in Inflammatory Profile in Tuberculosis

PMCID: PMC3701709This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Spontaneous and deliberate future thinking: A dual process account

© 2019 Springer Nature.This is the final published version of an article published in Psychological Research, licensed under a Creative Commons Attri-bution 4.0 International License. Available online at: https://doi.org/10.1007/s00426-019-01262-7.In this article, we address an apparent paradox in the literature on mental time travel and mind-wandering: How is it possible that future thinking is both constructive, yet often experienced as occurring spontaneously? We identify and describe two ‘routes’ whereby episodic future thoughts are brought to consciousness, with each of the ‘routes’ being associated with separable cognitive processes and functions. Voluntary future thinking relies on controlled, deliberate and slow cognitive processing. The other, termed involuntary or spontaneous future thinking, relies on automatic processes that allows ‘fully-fledged’ episodic future thoughts to freely come to mind, often triggered by internal or external cues. To unravel the paradox, we propose that the majority of spontaneous future thoughts are ‘pre-made’ (i.e., each spontaneous future thought is a re-iteration of a previously constructed future event), and therefore based on simple, well-understood, memory processes. We also propose that the pre-made hypothesis explains why spontaneous future thoughts occur rapidly, are similar to involuntary memories, and predominantly about upcoming tasks and goals. We also raise the possibility that spontaneous future thinking is the default mode of imagining the future. This dual process approach complements and extends standard theoretical approaches that emphasise constructive simulation, and outlines novel opportunities for researchers examining voluntary and spontaneous forms of future thinking.Peer reviewe

Sex-biased parental care and sexual size dimorphism in a provisioning arthropod

The diverse selection pressures driving the evolution of sexual size dimorphism (SSD) have long been debated. While the balance between fecundity selection and sexual selection has received much attention, explanations based on sex-specific ecology have proven harder to test. In ectotherms, females are typically larger than males, and this is frequently thought to be because size constrains female fecundity more than it constrains male mating success. However, SSD could additionally reflect maternal care strategies. Under this hypothesis, females are relatively larger where reproduction requires greater maximum maternal effort – for example where mothers transport heavy provisions to nests. To test this hypothesis we focussed on digger wasps (Hymenoptera: Ammophilini), a relatively homogeneous group in which only females provision offspring. In some species, a single large prey item, up to 10 times the mother’s weight, must be carried to each burrow on foot; other species provide many small prey, each flown individually to the nest. We found more pronounced female-biased SSD in species where females carry single, heavy prey. More generally, SSD was negatively correlated with numbers of prey provided per offspring. Females provisioning multiple small items had longer wings and thoraxes, probably because smaller prey are carried in flight. Despite much theorising, few empirical studies have tested how sex-biased parental care can affect SSD. Our study reveals that such costs can be associated with the evolution of dimorphism, and this should be investigated in other clades where parental care costs differ between sexes and species