350 research outputs found
Foreword
It was July 1938 when Louis Wirth published his “Urbanism as a Way of Life” in the American Journal of Sociology. The paper was seen by many as the one defining the city as a social phenomenon. Looking beyond its physical structure, economic product or cultural institutions, the author discovers those “elements of urbanism which mark it as a distinctive mode of human group life” (Wirth 1938: 4).
Wirth argues that three key characteristics of cities — large population size, social heterogeneity, and population density — contribute to the development of a peculiarly “urban way of life” and a distinct “urban personality”. In
his opinion, for centuries casual observers have noted deep personality differences between urban and rural people and between nature-based and machinebased styles of living
In place of an end
Cities, since first of them were to be established centuries ago, have always been spaces full of social actions, mass activities and collective behaviors. It is because they had an unusual power to attract people. They were and still are influential, inspiring and they arouse interest. For many reasons cities are important
for common dwellers, but also for artists and thinkers. In 20th century Louis Wirth described urbanized areas in terms of high population density, social diversity and large size of population — features which seem to be obvious and natural
On the existence of traveling waves in the 3D Boussinesq system
We extend earlier work on traveling waves in premixed flames in a
gravitationally stratified medium, subject to the Boussinesq approximation. For
three-dimensional channels not aligned with the gravity direction and under the
Dirichlet boundary conditions in the fluid velocity, it is shown that a
non-planar traveling wave, corresponding to a non-zero reaction, exists, under
an explicit condition relating the geometry of the crossection of the channel
to the magnitude of the Prandtl and Rayleigh numbers, or when the advection
term in the flow equations is neglected.Comment: 15 pages, to appear in Communications in Mathematical Physic
A case of multiple abnormalities of the azygos venous system: a praeaortic interazygos vein
The posterior thoracic wall, an area drained by the azygos venous system, is
a common site for surgical intervention. Since the venous part of the cardiovascular
system is subject to most common variation, abnormalities in the azygos
venous system are often reported. Some of the anatomical variants have significant
clinical implications for computed tomography image assessment and
mediastinal surgery.
During dissection of the posterior mediastinum in a 76 year-old Caucasian male
cadaver we found a rare variation in the azygos venous system. The hemiazygos
vein drained the left 9th to 11th left posterior intercostal veins. While passing ventrally
to the aorta at the level of the body of the eighth thoracic vertebra it was
joined by two separate vessels found to be the continuations of the 7th and 8th left
posterior intercostal veins. The resultant dilated vessel, termed the "interazygos
vein", then opened into the azygos vein on the right side of the vertebral column.
Variation in the azygos venous system has often been reported, but the abnormality
observed by us appears to be extremely rare. The interazygos vein passing
ventrally to the aorta may mimic enlarged lymph nodes and cause misinterpretation
of a computed tomography image or, if accidentally damaged during mediastinal
surgery, may lead to intraoperative haemorrhage. To the best of our knowledge
this report provides new data of potential clinical significance
Miasto (post)socjalistyczne i świat społeczny jego mieszkańców
The article presents analysis of changes both in urban space and social consciousness of city dwellers of the Silesian city called Tychy. Authors refer to the empirical studies undertaken in 80’s/90’s of XXth century and in the beginning of second decade of XXIst century. Tychy has been considered as a city without perspectives for the future but after processes of transformation it is now an approachable and attractive urban space
Short-time stability of scalar viscous shocks in the inviscid limit by the relative entropy method
We consider inviscid limits to shocks for viscous scalar conservation laws in one space dimension, with strict convex fluxes. We show that we can obtain sharp estimates in L-2 for a class of large perturbations and for any bounded time interval. Those perturbations can be chosen big enough to destroy the viscous layer. This shows that the fast convergence to the shock does not depend on the fine structure of the viscous layers. This is the first application of the relative entropy method developed by N. Leger [Arch. Ration. Mech. Anal., 199 (2011), pp. 761-778] and N. Leger and A. Vasseur [Arch. Ration. Mech. Anal., 201 (2011), pp. 271-302] to the study of an inviscid limit to a shock.open1
On the variational limits of lattice energies on prestrained elastic bodies
We study the asymptotic behaviour of the discrete elastic energies in
presence of the prestrain metric , assigned on the continuum reference
configuration . When the mesh size of the discrete lattice in
goes to zero, we obtain the variational bounds on the limiting (in the sense of
-limit) energy. In case of the nearest-neighbour and
next-to-nearest-neibghour interactions, we derive a precise asymptotic formula,
and compare it with the non-Euclidean model energy relative to
Why place matters in residential care: the mediating role of place attachment in the relation between adolescents’ rights and psychological well-being
Little evidence exists on the relationship between rights’ perceptions and well-being outcomes during the adolescence, and particularly in care, as well as on the mediating role of place attachment. Young people in residential care are psychologically and socially vulnerable, showing greater difficulties than their peers do in the family. Youth’s rights fulfilment in residential care may positively affect their psychological functioning together with positive attachments to this place. A sample of 365 adolescents in residential care settings (M = 14.71, SD = 1.81) completed a set of self-reported measures, specifically, the Rights perceptions scale, the Place attachment scale and Scales of psychological well-being. Results revealed significant mediating effects of place attachment (Global scale and subscales of Friends Bonding and Place Dependence) on the relationship between Participation and Protection rights in residential care and Psychological well-being (Positive Relations with others, Personal Growth and Self-Acceptance). The positive role of rights fulfilment in residential care, specifically participation opportunities, as well as the role of youth’s attachment to the care setting are discussed based on previous evidence and theoretical assumptions. A set of practical implications is described.info:eu-repo/semantics/acceptedVersio
Relative entropy and the stability of shocks and contact discontinuities for systems of conservation laws with non BV perturbations
We develop a theory based on relative entropy to show the uniqueness and L^2
stability (up to a translation) of extremal entropic Rankine-Hugoniot
discontinuities for systems of conservation laws (typically 1-shocks, n-shocks,
1-contact discontinuities and n-contact discontinuities of large amplitude)
among bounded entropic weak solutions having an additional trace property. The
existence of a convex entropy is needed. No BV estimate is needed on the weak
solutions considered. The theory holds without smallness condition. The
assumptions are quite general. For instance, strict hyperbolicity is not needed
globally. For fluid mechanics, the theory handles solutions with vacuum.Comment: 29 page
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