Network effects in a human capital based economic growth model

We revisit a recently introduced agent model[ACS {\bf 11}, 99 (2008)], where economic growth is a consequence of education (human capital formation) and innovation, and investigate the influence of the agents' social network, both on an agent's decision to pursue education and on the output of new ideas. Regular and random networks are considered. The results are compared with the predictions of a mean field (representative agent) model.Comment: to appear in Physica

O Novo Evangelho de Djonga : seculariza??o do corpo negro no mundo do rap.

Programa de P?s-Gradua??o em Comunica??o. Instituto de Ci?ncias Sociais e Aplicadas, Universidade Federal de Ouro Preto.Gustavo Pereira Marques, o Djonga ? popularmente conhecido no universo do rap por sua produ??o fonogr?fica com apurada den?ncia ao sistema social vigente, na qual os diversos modos de poder se entrecruzam por meio de uma refinada elabora??o cr?tica. Pela reatualiza??o narrativa dos versos dos Racionais Mc's, o rapper constr?i o que entendemos como um universo particular, atrav?s do qual sua autointitula??o como Deus recria as potencialidades do corpo negro pelo reposicionamento deste a um local sacralizado. Desta forma, esta disserta??o tem por objetivo principal compreender as formas utilizadas pelo rapper para a inaugura??o de um instante de den?ncia p?s Racionais Mc's, em que o reconhecimento e a identidade tematizados instituem um movimento horizontal de tensionamento, mas, sobretudo, de autoaceita??o entre os negros, e inaugura uma nova percep??o coletiva consciente por meio do Rap. Para sua realiza??o, optou-se pelo recorte nos quatro primeiros ?lbuns produzidos pelo cantor em sua carreira solo: Heresia (2017), O menino que queria ser Deus (2018), Ladr?o (2019), Hist?rias da Minha ?rea (2020). A percep??o da cultura midi?tica como meio para a propaga??o da marca??o das viol?ncias e da pr?pria sacraliza??o da negritude ser? observada em quatro videoclipes: Junho de 94 (2018), Corra (2018), Hat-Trick (2019) e Eu vou (2019). Por meio de categorias como a descoloniza??o do olhar e a est?tica da correria, quest?es caras ? reflex?o te?rica sobre a ancestralidade e a representa??o racial s?o articuladas com a observa??o anal?tica sobre a cultura midi?tica e seus desdobramentos em rela??o ? comunica??o e ? produ??o musical contempor?nea, mais especificamente ?s pertencentes ao rap brasileiro.Gustavo Pereira Marques, Djonga is popularly known in the world of rap for his phonographic production with a sharp denunciation of the social system, in which the different modes of power intertwine through refined critical criticism. Through the narrative update of the Racionais Mc's verses, the rapper builds what we understand as a particular universe, through which his self-title as God recreates as potentialities of the black body by repositioning it to a sacred place. In this way, this dissertation has as main objective to understand the ways used by the rapper for the inauguration of an instant of denunciation after Racionais Mc's, in which the thematic recognition and identity instituted a horizontal movement of tension, but, above all, of self-acceptance between the blacks, and inaugurates a new conscious collective perception. For its realization, we chose to cut out the first four albums obtained by the singer in his solo career: Heresia (2017), O menino que queria ser Deus (2018), Ladr?o (2019), Hist?rias da Minha ?rea (2020). The perception of media culture as a means for the propagation of the marking of violence and the sacredness of blackness will be observed in four video clips: June 94 (2018), Corra (2018), Hat-Trick (2019) and Eu vou (2019). Through categories such as the decolonization of the gaze and the aesthetics of the rush, questions dear to the theoretical reflection on ancestry and racial representation are articulated with the analytical observation about media culture and its developments in relation to contemporary musical production, more specific to belonging to Brazilian rap

Prospects for measurement and control of the scattering length of metastable helium using photoassociation techniques

A numerical investigation of two-laser photoassociation (PA) spectroscopy on spin-polarized metastable helium (He*) atoms is presented within the context of experimental observation of the least-bound energy level in the scattering potential and subsequent determination of the s-wave scattering length. Starting out from the model developed by Bohn and Julienne [Phys. Rev. A \textbf{60}, (1999) 414], PA rate coefficients are obtained as a function of the parameters of the two lasers. The rate coefficients are used to simulate one- and two-laser PA spectra. The results demonstrate the feasibility of a spectroscopic determination of the binding energy of the least-bound level. The simulated spectra may be used as a guideline when designing such an experiment, whereas the model may also be employed for fitting experimentally obtained PA spectra. In addition, the prospects for substantial modification of the He* scattering length by means of optical Feshbach resonances are considered. Several experimental issues relating to the numerical investigation presented here are discussed.Comment: 9 pages, 7 figure

A dark hole in our understanding of marine ecosystems and their services : perspectives from the mesopelagic community

In the face of increasing anthropogenic pressures acting on the Earth system, urgent actions are needed to guarantee efficient resource management and sustainable development for our growing human population. Our oceans - the largest underexplored component of the Earth system - are potentially home for a large number of new resources, which can directly impact upon food security and the wellbeing of humanity. However, the extraction of the resources fostered by marine ecosystems has repercussions for biodiversity and the oceans ability to sequester green house gases and thereby climate. In the search for new “resources to unlock the economic potential of the global oceans, recent observations have identified a large unexploited biomass of mesopelagic fish living in the deep ocean. This biomass has recently been estimated to be 10 billion metric tonnes, at least 10 times larger than previous estimates. If we are able to exploit this community at sustainable levels without impacting upon biodiversity and compromising the oceans’ ability to sequester carbon, we can produce more food and potentially many new nutraceutical products. However, to meet the needs of present generations without compromising the needs of future generations, we need to guarantee a sustainable exploitation of these resources. To do so requires a holistic assessment of the community and an understanding of the mechanisms controlling this biomass, its role in the preservation of biodiversity and its influence on climate as well as management tools able to weigh the costs and benefits of exploitation of this community

Transmission of mitochondrial DNA following assisted reproduction and nuclear transfer

Review of the articleMitochondria are the organelles responsible for producing the majority of a cell's ATP and also play an essential role in gamete maturation and embryo development. ATP production within the mitochondria is dependent on proteins encoded by both the nuclear and the mitochondrial genomes, therefore co-ordination between the two genomes is vital for cell survival. To assist with this co-ordination, cells normally contain only one type of mitochondrial DNA (mtDNA) termed homoplasmy. Occasionally, however, two or more types of mtDNA are present termed heteroplasmy. This can result from a combination of mutant and wild-type mtDNA molecules or from a combination of wild-type mtDNA variants. As heteroplasmy can result in mitochondrial disease, various mechanisms exist in the natural fertilization process to ensure the maternal-only transmission of mtDNA and the maintenance of homoplasmy in future generations. However, there is now an increasing use of invasive oocyte reconstruction protocols, which tend to bypass mechanisms for the maintenance of homoplasmy, potentially resulting in the transmission of either form of mtDNA heteroplasmy. Indeed, heteroplasmy caused by combinations of wild-type variants has been reported following cytoplasmic transfer (CT) in the human and following nuclear transfer (NT) in various animal species. Other techniques, such as germinal vesicle transfer and pronuclei transfer, have been proposed as methods of preventing transmission of mitochondrial diseases to future generations. However, resulting embryos and offspring may contain mtDNA heteroplasmy, which itself could result in mitochondrial disease. It is therefore essential that uniparental transmission of mtDNA is ensured before these techniques are used therapeutically

Does a small cost share reflect a negligible role for energy in economic production? Testing for aggregate production functions including capital, labor, and useful exergy through a cointegration-based method

Neoclassical models disregard the role of energy in production, equating a factor's output elasticity with its cost share, but failing to explain growth without a residual term. In contrast, ecological economics acknowledges energy's importance in production, regardless of its cost share. The aggregate production function (APF) concept, central to neoclassical theory, is also disputed. We apply cointegration analysis to test for APFs between output, capital, and labor. We investigate the inclusion of energy inputs, measuring energy's capacity to generate productive work (useful exergy). Plausible APFs must verify cointegration and Granger-causality between output and inputs; and non-negative output elasticities. This method recognizes cases where: a) plausible APFs don't exist; b) energy impacts growth directly; c) energy impacts growth indirectly, through other inputs. We apply the method to Portugal (1960-2009), considering standard and quality-corrected capital and labor measures. Plausible APFs are rarely obtained for capital-labor models. When they are, the residual growth component is large, and output elasticities disagree with historical cost shares. However, the residual is virtually eliminated for capital-labor-energy models with two cointegration relationships: a) a capital-labor APF, with output elasticities matching historical cost shares; b) a function estimating capital from useful exergy. These models reconcile energy's significance in production with cost-share neoclassical assumptions

Connectionist natural language parsing

The key developments of two decades of connectionist parsing are reviewed. Connectionist parsers are assessed according to their ability to learn to represent syntactic structures from examples automatically, without being presented with symbolic grammar rules. This review also considers the extent to which connectionist parsers offer computational models of human sentence processing and provide plausible accounts of psycholinguistic data. In considering these issues, special attention is paid to the level of realism, the nature of the modularity, and the type of processing that is to be found in a wide range of parsers

Investigating the association between obesity and asthma in 6- to 8-year-old Saudi children:a matched case-control study

Background: Previous studies have demonstrated an association between obesity and asthma, but there remains considerable uncertainty about whether this reflects an underlying causal relationship. Aims: To investigate the association between obesity and asthma in pre-pubertal children and to investigate the roles of airway obstruction and atopy as possible causal mechanisms. Methods: We conducted an age- and sex-matched case–control study of 1,264 6- to 8-year-old schoolchildren with and without asthma recruited from 37 randomly selected schools in Madinah, Saudi Arabia. The body mass index (BMI), waist circumference and skin fold thickness of the 632 children with asthma were compared with those of the 632 control children without asthma. Associations between obesity and asthma, adjusted for other potential risk factors, were assessed separately in boys and girls using conditional logistic regression analysis. The possible mediating roles of atopy and airway obstruction were studied by investigating the impact of incorporating data on sensitisation to common aeroallergens and measurements of lung function. Results: BMI was associated with asthma in boys (odds ratio (OR)=1.14, 95% confidence interval (CI), 1.08–1.20; adjusted OR=1.11, 95% CI, 1.03–1.19) and girls (OR=1.37, 95% CI, 1.26–1.50; adjusted OR=1.38, 95% CI, 1.23–1.56). Adjusting for forced expiratory volume in 1 s had a negligible impact on these associations, but these were attenuated following adjustment for allergic sensitisation, particularly in girls (girls: OR=1.25; 95% CI, 0.96–1.60; boys: OR=1.09, 95% CI, 0.99–1.19). Conclusions: BMI is associated with asthma in pre-pubertal Saudi boys and girls; this effect does not appear to be mediated through respiratory obstruction, but in girls this may at least partially be mediated through increased risk of allergic sensitisation