1,211 research outputs found
Macro and Micro Dynamics of City Size Distributions: The Case of Israel
We study the distribution of sizes in the Israeli system of cities, using a rank-size representation of population distributions from 1950 to 2005. Based on a multiplicative model of proportionate growth, we develop a quantitative comparison relating the change in the rank-size curves to the change in the real data of Israeli cities during this period. At the level of macro dynamics, there is good agreement between the model and the real data. At the micro level, however, the model is less successful as the mean variation of the cities’ rank during the period studied is much larger in the model than in the real data. To illustrate this difference, we use the rankclock representation
The Network Analysis of Urban Streets: A Primal Approach
The network metaphor in the analysis of urban and territorial cases has a
long tradition especially in transportation/land-use planning and economic
geography. More recently, urban design has brought its contribution by means of
the "space syntax" methodology. All these approaches, though under different
terms like accessibility, proximity, integration,connectivity, cost or effort,
focus on the idea that some places (or streets) are more important than others
because they are more central. The study of centrality in complex
systems,however, originated in other scientific areas, namely in structural
sociology, well before its use in urban studies; moreover, as a structural
property of the system, centrality has never been extensively investigated
metrically in geographic networks as it has been topologically in a wide range
of other relational networks like social, biological or technological. After
two previous works on some structural properties of the dual and primal graph
representations of urban street networks (Porta et al. cond-mat/0411241;
Crucitti et al. physics/0504163), in this paper we provide an in-depth
investigation of centrality in the primal approach as compared to the dual one,
with a special focus on potentials for urban design.Comment: 19 page, 4 figures. Paper related to the paper "The Network Analysis
of Urban Streets: A Dual Approach" cond-mat/041124
Information for Operation of Water Supply Systems
Introduction: Water requirements increase as more people use more water for domestic purposes. The increase is augmented as technological advances add to the water needs of agriculture and industry. Additional urban landscaping adds further to the demand. Simultaneously, the same forces increase demands for flood control, hydrelectric power, and navigation; and a more urbanized population want more flows preserved for productive natural environments, recreational use, and aesthetic enjoyment. The response over the years to these growing demands on water resources has been to supply increasing amounts of water and greater levels of development for other purposes by building more projects, larger projects, multipurpose projects, and multiproject systems. The construction and operation of these facilities have changed the flow and water quality regimes of our rivers. Some majore river basins are now approaching full utilization of their runoff (U.S. Water Resources Council 1978). As the opportunities for water project construction are exhausted, the name of the game shifts to systems operation for more precise water delivery when and where it is needed. More rapid and reliable data collection can provide a better information base for determing need. Greater benefits can then be achieved by applying optimization models on a real time basis and promtly using the results in automated control systems. Fortunately, the needs for more carefully controlled water resources systems operation come at a time when advances in electronics are offering a new surveillance and control technologies. Greater efficiency can be achieved by more rapid measurement and thorough analysis for application of the informatino that has been used in the past as a basis for systems operation. However, full advantage of the capabilities of the electronic age can only be achieved by gathering information that has previously been impossible or impractical to obtain, developing more comprehensive analytic models, and applying the results with more precise automated control systems. The purpose of this paper is to stimulate thinking about what can be done. As a starting point, we will gather ideas by diagraming the natural cycle that supplies our water, identifying losses and inefficiencies within it that might be reduced through more effective use of information for operating purposes, and examining existing reservoir operation procedures. The resulting list of potential applications for information and control systems provide direction for refining current automated operating systems. We can end by dreaming about a fully automated system for irrigation water delivery
Limits on the low energy antinucleon-nucleus annihilations from the Heisenberg principle
We show that the quantum uncertainty principle puts some limits on the
effectiveness of the antinucleon-nucleus annihilation at very low energies.
This is caused by the fact that the realization a very effective short-distance
reaction process implies information on the relative distance of the reacting
particles. Some quantitative predictions are possible on this ground, including
the approximate A-independence of antinucleon-nucleus annihilation rates.Comment: 10 pages, no figure
Physical Electronics and Surface Physics
Contains research objectives, summary of research and reports on three research projects.National Aeronautics and Space Administration (Grant NGR-22-009-091)M.I.T. Cabot Solar Energy FundJoint Services Electronics Programs (U. S. Army, U.S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E
Social origin, schooling and individual change in intelligence during childhood influence long-term mortality: a 68-year follow-up study
Background Intelligence at a single time-point has been linked to health outcomes. An individual's IQ increases with longer schooling, but the validity of such increase is unclear. In this study, we assess the hypothesis that individual change in the performance on IQ tests between ages 10 and 20 years is associated with mortality later in life
Diabetes status and post-load plasma glucose concentration in relation to site-specific cancer mortality: findings from the original Whitehall study
ObjectiveWhile several studies have reported on the relation of diabetes status with pancreatic cancer risk, the predictive value of this disorder for other malignancies is unclear. Methods: The Whitehall study, a 25year follow-up for mortality experience of 18,006 men with data on post-challenge blood glucose and self-reported diabetes, allowed us to address these issues. Results: There were 2158 cancer deaths at follow-up. Of the 15 cancer outcomes, diabetes status was positively associated with mortality from carcinoma of the pancreas and liver, while the relationship with lung cancer was inverse, after controlling for a range of potential covariates and mediators which included obesity and socioeconomic position. After excluding deaths occurring in the first 10years of follow-up to examine the effect of reverse causality, the magnitude of the relationships for carcinoma of the pancreas and lung was little altered, while for liver cancer it was markedly attenuated. Conclusions: In the present study, diabetes status was related to pancreatic, liver, and lung cancer risk. Cohorts with serially collected data on blood glucose and covariates are required to further examine this area
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Motherhood, Moral Authority and the Charismatic Matriarch in the Aftermath of Lethal Violence
Images of maternal suffering are an evocative and powerful means of communication in a world where the private grief of victims has increasingly become subject to commodification and public consumption. This article looks at the influence of bereaved mothers as symbols of respect, peace and dignity in the aftermath of violence, and as a result their persuasive presence in family activism. Drawing upon two case studies, this article explores the importance of victims’ stories in public life and, in particular, the presence of the charismatic matriarch in creating communities of solidarity, raising awareness of harms that have previously gone unheard and prompting policy change. It considers the ‘canonical’ story of the mother in public life and concludes by arguing that more attention should be paid to victims’ stories and their influence on policy-making, politics and eventually in becoming public grievances
Psychosocial functioning and intelligence both partly explain socioeconomic inequalities in premature death. A population-based male cohort study
The possible contributions of psychosocial functioning and intelligence differences to socioeconomic status (SES)-related inequalities in premature death were investigated. None of the previous studies focusing on inequalities in mortality has included measures of both psychosocial functioning and intelligence.The study was based on a cohort of 49 321 men born 1949-1951 from the general community in Sweden. Data on psychosocial functioning and intelligence from military conscription at ∼18 years of age were linked with register data on education, occupational class, and income at 35-39 years of age. Psychosocial functioning was rated by psychologists as a summary measure of differences in level of activity, power of initiative, independence, and emotional stability. Intelligence was measured through a multidimensional test. Causes of death between 40 and 57 years of age were followed in registers.The estimated inequalities in all-cause mortality by education and occupational class were attenuated with 32% (95% confidence interval: 20-45%) and 41% (29-52%) after adjustments for individual psychological differences; both psychosocial functioning and intelligence contributed to account for the inequalities. The inequalities in cardiovascular and injury mortality were attenuated by as much as 51% (24-76%) and 52% (35-68%) after the same adjustments, and the inequalities in alcohol-related mortality were attenuated by up to 33% (8-59%). Less of the inequalities were accounted for when those were measured by level of income, with which intelligence had a weaker correlation. The small SES-related inequalities in cancer mortality were not attenuated by adjustment for intelligence.Differences in psychosocial functioning and intelligence might both contribute to the explanation of observed SES-related inequalities in premature death, but the magnitude of their contributions likely varies with measure of socioeconomic status and cause of death. Both psychosocial functioning and intelligence should be considered in future studies
Kaons production at finite temperature and baryon density in an effective relativistic mean field model
We investigate the kaons production at finite temperature and baryon density
by means of an effective relativistic mean-field model with the inclusion of
the full octet of baryons. Kaons are considered taking into account of an
effective chemical potential depending on the self-consistent interaction
between baryons. The obtained results are compared with a minimal coupling
scheme, calculated for different values of the anti-kaon optical potential.Comment: 3 pages, contribution presented to the International Conference on
Exotic Atoms and Related Topic
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