1,872 research outputs found
Bibliotecas pĂșblicas em tempos difĂceis
The study of everyday-life during World War II showed how attendance and valuation of public libraries may considerably increase during âHard Timesâ. Some of the reasons are expected â free reading â and some other are occasionally surprising â shelter under adverse atmospheric conditions, appreciated levels of comfort such as lighting, desired (and recently-lost?) social interaction. It should be noted that, in some European and North-American countries, there were neighbourhood libraries located throughout the big city, acting as estimated proximity services.
Being aware of this reality helps us understand why cultural and recreational services, and nowadays Web services too, are not less, but even more important in times of crisis.
In Portugal, and in the last decade, public libraries have been steadily degraded through the reduction of adequately qualified personnel and through a generalised lack of the updating of collections, along with other cuts. Certain technological options do not appear to have been made according to the needs of readers but following non-transparent investment choices away of public scrutiny. If Wi-Fi is quite widespread now, ebooks have not entered public libraries yet.
However, we may question:
What shelters do we want in our city to read in, and how do we want to read? âSecludedlyâ alone, in a community without propinquity? Do we tolerate intrusions while reading in public? Who pushes those technological choices? And above all: if we are deprived of these spaces or of these services, who will fill this void? Will they still be "built for us"?O estudo de quotidianos da 2ÂȘ Grande Guerra mostrou como a afluĂȘncia e valorização das bibliotecas pĂșblicas podem aumentar consideravelmente em Tempos DifĂceis. Por razĂ”es expectĂĄveis â leitura gratuita â e por outras talvez mais surpreendentes â abrigo em condiçÔes atmosfĂ©ricas adversas, iluminação, nĂveis de conforto apreciados, interação social desejada (e recĂ©m-perdida?). Note-se que, em alguns paĂses da Europa e no Norte da AmĂ©rica, havia bibliotecas de bairro distribuĂdas pela cidade grande, atuando como estimados serviços de proximidade. Conhecer essa realidade ajuda a compreender porque serviços culturais, de recreação (e hoje em dia tambĂ©m serviços Web) sĂŁo, nĂŁo menos, mas ainda mais importantes em tempos de crise.
Em Portugal, na Ășltima dĂ©cada, as bibliotecas pĂșblicas tĂȘm sido paulatinamente degradadas pela redução no pessoal com qualificação adequada e por uma generalizante falta de atualização das coleçÔes, a par doutros cortes. Certas opçÔes tecnolĂłgicas nĂŁo parecem ter sido feitas de acordo com necessidades de leitores mas por opçÔes de investimento nĂŁo transparentes para o pĂșblico. Se o Wi-Fi estĂĄ bastante generalizado, os ebooks nĂŁo chegaram ainda Ă s bibliotecas pĂșblicas.
Entretanto podemos questionar:
Que abrigos queremos na cidade e como queremos ler? Esconsamente sĂłs, em comunidade sem propinquidade? Toleramos intrusĂ”es na leitura pĂșblica? Quem empurra estas opçÔes tecnolĂłgicas? E acima de tudo: se ficarmos sem estes espaços ou serviços, quem irĂĄ preencher o vazio? SerĂŁo ainda âconstruĂdos para nĂłsâ
Suppressors of selection
Inspired by recent works on evolutionary graph theory, an area of growing
interest in mathematical and computational biology, we present the first known
examples of undirected structures acting as suppressors of selection for any
fitness value . This means that the average fixation probability of an
advantageous mutant or invader individual placed at some node is strictly less
than that of this individual placed in a well-mixed population. This leads the
way to study more robust structures less prone to invasion, contrary to what
happens with the amplifiers of selection where the fixation probability is
increased on average for advantageous invader individuals. A few families of
amplifiers are known, although some effort was required to prove it. Here, we
use computer aided techniques to find an exact analytical expression of the
fixation probability for some graphs of small order (equal to , and
) proving that selection is effectively reduced for . Some numerical
experiments using Monte Carlo methods are also performed for larger graphs.Comment: New title, improved presentation, and further examples. Supporting
Information is also include
Fast and asymptotic computation of the fixation probability for Moran processes on graphs
Evolutionary dynamics has been classically studied for homogeneous
populations, but now there is a growing interest in the non-homogenous case.
One of the most important models has been proposed by Lieberman, Hauert and
Nowak, adapting to a weighted directed graph the classical process described by
Moran. The Markov chain associated with the graph can be modified by erasing
all non-trivial loops in its state space, obtaining the so-called Embedded
Markov chain (EMC). The fixation probability remains unchanged, but the
expected time to absorption (fixation or extinction) is reduced. In this paper,
we shall use this idea to compute asymptotically the average fixation
probability for complete bipartite graphs. To this end, we firstly review some
recent results on evolutionary dynamics on graphs trying to clarify some
points. We also revisit the 'Star Theorem' proved by Lieberman, Hauert and
Nowak for the star graphs. Theoretically, EMC techniques allow fast computation
of the fixation probability, but in practice this is not always true. Thus, in
the last part of the paper, we compare this algorithm with the standard Monte
Carlo method for some kind of complex networks.Comment: Corrected typo
Presencia de Mirosphinctes (Ammonitina, Perisphinctacea) en la zona Subbética (Cordilleras Béticas, España)
Todavia no habĂa sido citado en las Cordilleras bĂ©ticas (Zona SubbĂ©tica) el gĂ©nero Mirosphinctes; recientemente ha sido encontrado en la zona de bimammatum de Sierra Gorda (Loja, España) un ejemplar clasificado como nueva especie (Mirosphinctes myczynskii nov. sp.) similar a la fauna procedente de la parte occidental de Cuba
[Review of] Library of Congress. The Card Catalog: Books, Cards, and Literary Treasures
Review of the book "The Card Catalog: Books, Cards, and Literary Treasures" published by the Library of Congres
The SĂĄmi Library, North of the North: colonialism, resistance and reading in a public library
The SĂĄmi in Sweden are welcomed as readers of the main language, dissatisfied by the relegated status of
their culture as an ethnic minority. The SĂĄmi Library in Jokkmokk is a library for the SĂĄmi culture and the
SĂĄpmi. While SĂĄmi culture is resisting and transfiguring itself, neoliberal arrangements, the privatisation
of public services, new language laws and the Libraries Bill have put additional challenges to the library.
The case study of this library is used to discuss what an indigenous library is. The acknowledgement of the
colonial past and the demand for respectful recognition are advanced as fundamental requirements for a
democratic use of the documentary resources and a realisation of cultural rights
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