1,375 research outputs found
Subjective Wellbeing, Health and Ageing
Life satisfaction dips around middle age and rises in older age in high-income, English-speaking countries, but that is not a universal pattern, according to a new report. In contrast, residents of other regions -- such as the former Soviet Union, Eastern Europe, Latin America and sub-Saharan Africa -- grow increasingly less satisfied as they age. The study -- conducted by researchers from Princeton University's Woodrow Wilson School of Public and International Affairs, Stony Brook University and University College London -- highlights how residents of different regions across the world experience varying life-satisfaction levels and emotions as they age
Fast Entropy Estimation for Natural Sequences
It is well known that to estimate the Shannon entropy for symbolic sequences
accurately requires a large number of samples. When some aspects of the data
are known it is plausible to attempt to use this to more efficiently compute
entropy. A number of methods having various assumptions have been proposed
which can be used to calculate entropy for small sample sizes. In this paper,
we examine this problem and propose a method for estimating the Shannon entropy
for a set of ranked symbolic natural events. Using a modified
Zipf-Mandelbrot-Li law and a new rank-based coincidence counting method, we
propose an efficient algorithm which enables the entropy to be estimated with
surprising accuracy using only a small number of samples. The algorithm is
tested on some natural sequences and shown to yield accurate results with very
small amounts of data
Quantum Interference and Inelastic Scattering in a Model Which-Way Device
A which-way device is one which is designed to detect which of 2 paths is
taken by a quantum particle, whether Schr\"odinger's cat is dead or alive. One
possible such device is represented by an Aharonov-Bohm ring with a quantum dot
on one branch. A charged cantilever or spring is brought close to the dot as a
detector of the presence of an electron. The conventional view of such a device
is that any change in the state of the cantilever implies a change in the
electron state which will in turn destroy the interference effects. In this
paper we show that it is in fact possible to change the state of the oscillator
while preserving the quantum interference phenomenon.Comment: 5 pages, 7 figures, Localisation 2002 Toky
Recommended from our members
Critical reflections on designing product service systems
In response to unsustainability and the prospect of resource scarcity, lifestyles dominated by resource throughput are being challenged. This paper focuses on a design experiment that sought to introduce alternative resource consumption pathways in the form of product service systems (PSS) to satisfy household demand and reduce consumer durable household waste. In contrast to many other PSS examples this project did not begin with sustainability benefits, rather the preferences of supply and demand actors and the bounded geographical locations represented by two UK housing developments. The paper addresses the process through which the concept PSS were designed, selected and evaluated, alongside the practical and commercial parameters of the project. It proposes the need for a shift to further emphasize the importance of the design imperative in creating different PSS outcomes that reorganize relationships between people, resources and the environment
Better by design: Business preferences for environmental regulatory reform
We present the preferences for environmental regulatory reform expressed by 30 UK businesses and industry bodies from 5 sectors. While five strongly preferred voluntary regulation, seven expressed doubts about its effectiveness, and 18 expressed no general preference between instrument types. Voluntary approaches were valued for flexibility and lower burdens, but direct regulation offered stability and a level playing field. Respondents sought regulatory frameworks that: are coherent; balance clarity, prescription and flexibility; are enabled by positive regulatory relationships; administratively efficient; targeted according to risk magnitude and character; evidence-based and that deliver long-term market stability for regulatees. Anticipated differences in performance between types of instrument can be undermined by poor implementation. Results underline the need for policy makers and regulators to tailor an effective mix of instruments for a given sector, and to overcome analytical, institutional and political barriers to greater coherence, to better coordinate existing instruments and tackle new environmental challenges as they emerge
Loose Ends for the Exomoon Candidate Host Kepler-1625b
The claim of an exomoon candidate in the Kepler-1625b system has generated
substantial discussion regarding possible alternative explanations for the
purported signal. In this work we examine in detail these possibilities. First,
the effect of more flexible trend models is explored and we show that
sufficiently flexible models are capable of attenuating the signal, although
this is an expected byproduct of invoking such models. We also explore trend
models using X and Y centroid positions and show that there is no data-driven
impetus to adopt such models over temporal ones. We quantify the probability
that the 500 ppm moon-like dip could be caused by a Neptune-sized transiting
planet to be < 0.75%. We show that neither autocorrelation, Gaussian processes
nor a Lomb-Scargle periodogram are able to recover a stellar rotation period,
demonstrating that K1625 is a quiet star with periodic behavior < 200 ppm.
Through injection and recovery tests, we find that the star does not exhibit a
tendency to introduce false-positive dip-like features above that of pure
Gaussian noise. Finally, we address a recent re-analysis by Kreidberg et al
(2019) and show that the difference in conclusions is not from differing
systematics models but rather the reduction itself. We show that their
reduction exhibits i) slightly higher intra-orbit and post-fit residual
scatter, ii) 900 ppm larger flux offset at the visit change, iii)
2 times larger Y-centroid variations, and iv) 3.5 times
stronger flux-centroid correlation coefficient than the original analysis.
These points could be explained by larger systematics in their reduction,
potentially impacting their conclusions.Comment: 21 pages, 4 tables, 11 figures. Accepted for publication in The
Astronomical Journal, January 202
Dilemma of natural resource abundance: a case study of Kuwait
There is a lively debate about the relationship between a nation’s natural resource abundance and economic growth. Some view natural resource abundance as a curse, whereas others view it as a blessing. This study examines the economic, social, and political effects of resource abundance in an oil-rich country, Kuwait, using data from 1984 to 2014. This study analyzes the short- and long-run impacts of resource rents on per capita gross domestic product (GDP), productivity, human capital, and institutional quality. The study reveals through autoregressive distributed lag modeling and error correction modeling that resource rents increase per capita GDP merely in the short-run; however, resource rents deteriorate productivity, human capital, and institutional quality in both the short and the long-run. These results indicate that, for Kuwait, the overreliance on its natural resources has been detrimental over the long-run. The study suggests that there is a need to improve the quality of institutions and enhance the level of human capital to get economic sustainability and development over time
Soft X-ray Excess in the Coma Cluster from a Cosmic Axion Background
We show that the soft X-ray excess in the Coma cluster can be explained by a
cosmic background of relativistic axions converting into photons in the cluster
magnetic field. We provide a detailed self-contained review of the cluster soft
X-ray excess, the proposed astrophysical explanations and the problems they
face, and explain how a 0.1-1 keV axion background naturally arises at
reheating in many string theory models of the early universe. We study the
morphology of the soft excess by numerically propagating axions through
stochastic, multi-scale magnetic field models that are consistent with
observations of Faraday rotation measures from Coma. By comparing to ROSAT
observations of the 0.2-0.4 keV soft excess, we find that the overall excess
luminosity is easily reproduced for
GeV. The resulting morphology is highly sensitive to the magnetic field
power spectrum. For Gaussian magnetic field models, the observed soft excess
morphology prefers magnetic field spectra with most power in coherence lengths
on scales over those with most power on scales. Within this scenario, we bound the mean energy of the
axion background to , the axion mass to , and derive a
lower bound on the axion-photon coupling GeV.Comment: 43 pages, 11 figure
Plasticity in transmission strategies of the malaria parasite, Plasmodium chabaudi : environmental and genetic effects
Parasites may alter their behaviour to cope with changes in the within-host environment. In particular, investment in transmission may alter in response to the availability of parasite resources or host immune responses. However, experimental and theoretical studies have drawn conflicting conclusions regarding parasites' optimal (adaptive) responses to deterioration in habitat quality. We analyse data from acute infections with six genotypes of the rodent malaria species to quantify how investment in transmission (gametocytes) is influenced by the within-host environment. Using a minimum of modelling assumptions, we find that proportional investment in gametocytogenesis increases sharply with host anaemia and also increases at low parasite densities. Further, stronger dependence of investment on parasite density is associated with greater virulence of the parasite genotype. Our study provides a robust quantitative framework for studying parasites' responses to the host environment and whether these responses are adaptive, which is crucial for predicting the short-term and evolutionary impact of transmission-blocking treatments for parasitic diseases
- …