Self-consistent characterization of light statistics

We demonstrate the possibility of a self-consistent characterization of the photon-number statistics of a light field by using photoemissive detectors with internal gain simply endowed with linear input/output responses. The method can be applied to both microscopic and mesoscopic photon-number regimes. The detectors must operate in the linear range without need of photon-counting capabilities.Comment: To be published in "Journal of Modern Optics

Metals, Machinery, and Mining Equipment Industries in South Africa: The Relationship between Power, Governance, and Technological Capabilities

The metals, machinery, and mining equipment industries have been at the heart of South Africa’s industrial ecosystem. Their central position is associated with the long-term importance of mining, with which there are extensive demand- and supply-side linkages. This chapter reviews key turning points in the development and restructuring of these value chains in post-apartheid South Africa, from 1994 to 2019. The overall record is of a basic steel industry that performed better in terms of value added relative to the more diversified downstream industries, despite government industrial policy targeting more labour-intensive downstream industries. The downstream machinery and equipment industry struggled to compete with imports in the 2000s and 2010s and only partially engaged with digitalization. In explaining these developments the grand bargains struck by the state with the main company producing basic steel and the use of procurement as a demand-side industrial policy are critically examined. The chapter also provides micro-level evidence of the evolving relationships between mining houses; engineering, procurement, and construction management services companies; and input suppliers along the value chain. Overall, it is argued that the relatively poor performance of this industry grouping in South Africa has been due to power asymmetries along the value chains, upstream concentration, high levels of fragmentation in the domestic ecosystem, the lack of key institutional ingredients, and poor policy design. Lessons for resource-endowed middle-income countries are discussed, and policy challenges for upgrading and diversification are presented

Ab initio many-body calculation of excitons in solid Ne and Ar

Absorption spectra, exciton energy levels and wave functions for solid Ne and Ar have been calculated from first principles using many-body techniques. Electronic band structures of Ne and Ar were calculated using the GW approximation. Exciton states were calculated by diagonalizing an exciton Hamiltonian derived from the particle-hole Green function, whose equation of motion is the Bethe-Salpeter equation. Singlet and triplet exciton series up to n=5 for Ne and n=3 for Ar were obtained. Binding energies and longitudinal-transverse splittings of n=1 excitons are in excellent agreement with experiment. Plots of correlated electron-hole wave functions show that the electron-hole complex is delocalised over roughly 7 a.u. in solid Ar.Comment: 6 page

Typing of a polymorphic human gene conferring susceptibility to insulin-dependent diabetes mellitus by picosecond-resolved FRET on non-purified/non-amplified genomic DNA

This work concerns the identification of the alleles of the polymorphic DQB1 gene of the human leukocyte antigen system, conferring susceptibility to the development of insulin-dependent diabetes mellitus (IDDM) in non-PCR amplified DNA samples and, more importantly, in crude cell extracts. Our method is based on the time-resolved analysis of a F\uf6rster energy-transfer mechanism that occurs in a dual-labelled fluorescent probe specific for the IDDM-associated DQB1-0201 allele. Such an oligonucleotide probe is labelled, at the two ends, by a pair of chromophores that operate as donor and acceptor in a F\uf6rster resonant energy transfer. The donor fluorescence is quenched with an efficiency that is strongly dependent on the donor-to-acceptor distance, hence on the configuration of the probe after hybridization with the various DQB1 alleles. By time-correlated single-photon counting, performed with an excitation/detection system endowed with 30-ps resolution, we measure the time-resolved fluorescence decay of the donor and discriminate, by means of the decaytime value, the DNA bearing the 'susceptible' allele from the DNAs bearing any other sequence in the same region of the DQB1 gene. We could also distinguish the presence of the DQB1-0201 allele in a homozygous versus a heterozygous condition

Aborto inseguro: determinantes sociais e iniquidades em saúde em uma população vulnerável, São Paulo, Brasil

This cross-sectional population-based study in a peripheral low-income community in São Paulo, Brazil, aimed to estimate the prevalence of unsafe abortion and identify the socio-demographic characteristics associated with it and its morbidity. The article discusses the study's results, based on univariate and multiple multinomial logistic regression analyses. The final regression models included: age at first intercourse 2 sex partners in the previous year (OR = 3.63); more live born children than the woman's self-reported ideal number (OR = 3.09); acceptance of the abortion due to insufficient economic conditions (OR = 4.07); black ethnicity/color (OR = 2.67); and low schooling (OR = 2.46), all with p 2 (OR = 3,63); número de filhos nascidos vivos > ideal (OR = 3,09); aceitação do aborto por falta de condições econômicas (OR = 4,07); etnia negra/cor preta (OR = 2,67); e escolaridade baixa (OR = 2,46), todos com p < 0,05. Foi utilizada na discussão uma abordagem voltada aos determinantes sociais da saúde, segundo conceito e modelo adotados pela WHO, e às iniquidades em saúde por esses geradas na ocorrência do aborto inseguro. Verificou-se que o aborto inseguro e características sociodemográficas são influenciados pelos determinantes sociais da saúde descritos, gerando nessa população iniquidades em saúde de proporções diversas.Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

Epidemiology of unsafe abortion in a poverty stricken environment Favela Inajar de Souza, São Paulo, Brazil

This article compares the results of a survey carried out recently in a poverty stricken environment in São Paulo, Brazil - a country where abortion is illegal in most circumstances- to data from Cuba - where abortion is safe and legal, and data registries are reliable. A cross-sectional survey was conducted in a community in the north side of the city, called Favela Inajar de Souza, with the purpose of estimating the frequency of unsafe, clandestine abortions and identifying socio-demographic characteristics and morbidity related to abortion in a poor population. All women aged 15 to 54 years that lived in this community (Census) were interviewed for this survey. The Chi-Square Test and the Fisher exact test were used for categorical variables, and analysis of variance was used for numeric variables. Throughout the analysis, the statistical significance level of 5% (p<0.05) was adopted. A high number of unsafe abortions and a high rate of post-abortion complications were detected in the studied population - the community of Favela Inajar. With regard to induced abortions, the only common features between the two populations were age and civil status. As opposed to what happens in Cuba, the analysis of the data from Favela Inajar shows that there were statistically significant associations between unsafe abortion and: income, educational level, internal migration and ethnicity. These findings indicate that this population is particularly vulnerable to unsafe abortion in face of the several forms of structural violence present in Brazil, which produce social inequity. The performance of safe and legal abortion, as is the case in Cuba, would change this scenario. Legalization of abortion in Brazil would mostly benefit poor women.Procurou-se, neste trabalho, comparar os Resultados de Pesquisa recente, realizada em São Paulo, Brasil, país em que o aborto é ilegal em quase todas as circunstâncias, com dados referentes a Cuba, país onde o aborto é legal e seguro, dispondo de registros confiáveis. Essa pesquisa foi sediada em uma comunidade da Zona Norte da cidade de São Paulo, Favela Inajar de Souza: um estudo transversal que teve por objetivo estimar a freqüência de Abortos Inseguros, bem como determinar as características sociodemográficas e a morbidade associadas a tal ocorrência, em uma população em situação de pobreza. Foram entrevistadas todas as mulheres entre 15 e 54 anos residentes na comunidade (Censo). Na análise dos dados foram empregados o teste exato de Fisher e o teste qui-quadrado para as variáveis categóricas, e a análise de variância (ANOVA) para as variáveis numéricas. Em toda a análise adotou-se um nível de significância de 5%, com p < 0,05. Encontrou-se, na população estudada, Favela Inajar, um alto número de abortos inseguros e alta porcentagem de complicações pós-aborto. Em comum com Cuba, quanto ao Aborto Induzido foi observada semelhança de perfil somente em relação à Idade e ao Estado Civil. Nos Resultados foram constatadas também - contrariamente ao que ocorre em Cuba - associações estatisticamente significativas entre Aborto Inseguro e Renda/Escolaridade (baixas), Aborto Inseguro e Etnia/Cor, Aborto Inseguro e Não Apoio do Parceiro, e Aborto Inseguro e Migração Interna - o que torna essa população especialmente vulnerável ao aborto inseguro frente às violências estruturais, geradoras de iniqüidade, vigentes no Brasil. O aborto legal e seguro, tal como em Cuba, transformaria essa realidade. A legalização do aborto beneficiaria, sobretudo, as mulheres pobres.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Medicina PreventivaUNIFESP, EPM, Depto. de Medicina PreventivaSciEL

Plasduino: an inexpensive, general purpose data acquisition framework for educational experiments

Based on the Arduino development platform, Plasduino is an open-source data acquisition framework specifically designed for educational physics experiments. The source code, schematics and documentation are in the public domain under a GPL license and the system, streamlined for low cost and ease of use, can be replicated on the scale of a typical didactic lab with minimal effort. We describe the basic architecture of the system and illustrate its potential with some real-life examples.Comment: 11 pages, 10 figures, presented at the XCIX conference of the Societ\`a Italiana di Fisic

Are Individuals Fickle-Minded?

Game theory has been used to model large-scale social events — such as constitutional law, democratic stability, standard setting, gender roles, social movements, communication, markets, the selection of officials by means of elections, coalition formation, resource allocation, distribution of goods, and war — as the aggregate result of individual choices in interdependent decision-making. Game theory in this way assumes methodological individualism. The widespread observation that game theory predictions do not in general match observation has led to many attempts to repair game theory by creating behavioral game theory, which adds corrective terms to the game theoretic predictions in the hope of making predictions that better match observations. But for game theory to be useful in making predictions, we must be able to generalize from an individual’s behavior in one situation to that individual’s behavior in very closely similar situations. In other words, behavioral game theory needs individuals to be reasonably consistent in action if the theory is to have predictive power. We argue on the basis of experimental evidence that the assumption of such consistency is unwarranted. More realistic models of individual agents must be developed that acknowledge the variance in behavior for a given individual