Exchange market pressure and the credibility of Macau's currency Board

In this study, we assess the credibility of the currency board arrangement (CBA) of the Macau Special Administrative Region by studying the relationship between exchange market pressure (EMP) and the anchors of a rule-based CBA, namely, interest rate arbitrage, exchange rate arbitrage and economic discipline. A pure CBA signals its credibility by allowing the first two anchors to function automatically and by pursuing sound fiscal policies. The analysis’ results suggest that Macau’s CBA has been characterised by a state of low volatility since late 1992, with the brief exception of the East Asian financial crisis period. The paper’s main finding is that fiscal fundamentals seem to have a more pronounced role in reducing EMP’s variability during periods of low volatility whilst interest rate arbitrage is more important in periods of high volatility. We conclude that Macau’s CBA is credible at present as reflected in the low frequency of observed EMP, in the narrowing of Macau’s interest rate differential vis-à-vis U.S. interest rates and in Macau’s substantial fiscal reserves.

Brane Isotropisation in Extra-Dimensional Tolman-Bondi Universe

We consider the dynamics of a 3-brane embedded in an extra-dimensional Tolman-Bondi Universe where the origin of space plays a special role. The embedding is chosen such that the induced matter distribution on the brane respects the spherical symmetry of matter in the extra dimensional space. The mirage cosmology on the probe brane is studied, resulting in an inhomogeneous and anisotropic four dimensional cosmology where the origin of space is also special. We then focus on the spatial geometry around the origin and show that the induced geometry, which is initially inhomogeneous and anisotropic, converges to an isotropic and homogeneous Friedmann-Lemaitre 4d space-time. For instance, when a 3-brane is embedded in a 5d matter dominated model, the 4d dynamics around the origin converge to a Friedmann-Lemaitre Universe in a radiation dominated epoch. We analyse this isotropisation process and show that it is a late time attractor.Comment: 16 pages, 8 figures, one reference adde

A Note on the Picard-Fuchs Equations for N=2 Seiberg-Witten Theories

A concise presentation of the PF equations for N=2 Seiberg-Witten theories for the classical groups of rank r with N_f massless hypermultiplets in the fundamental representation is provided. For N_f=0, all r PF equations can be given in a generic form. For certain cases with N_f\neq zero, not all equations are generic. However, in all cases there are at least r-2 generic PF equations. For these cases the classical part of the equations is generic, while the quantum part can be formulated using a method described in a previous paper by the authors, which is well suited to symbolic computer calculations.Comment: 25 pages, Latex; some new references adde

Plasmid DNA recovery from fermentation broths by a combined process of micro- and ultrafiltration : modeling and application

Microfiltration and ultrafiltration operations were used in tandem to isolate and purify a 6050 bp plasmid DNA (pDNA). To achieve primary isolation of the plasmid from fermentation broths, immediately after cell lysis, a 0.2 μm microfiltration membrane was selected for solid/liquid separation, which was performed in a diafiltration mode, as an alternative to centrifugation. Then to attain plasmid concentration and purification, an ultrafiltration membrane with a pore radius of 4.1 nm was selected. Permeation of pDNA and RNA in the two membrane steps was modeled using recently published mass transfer models applicable to the permeation of closed segmented chains and freely-jointed chains, respectively. The permeation of proteins and genomic DNA (gDNA) was also studied in these operations. The microfiltration operation allowed high plasmid and RNA permeation, as expected. It was observed that significant amounts of gDNA, previously precipitated during the cell lysis step, reappear in solution during the diafiltration step. The effect of the ionic strength on this apparent re-solubilization was investigated, by testing the addition of two different salts to the diafiltration buffer: CH3COOK and CaCl2. The results show that these salts can be used to control gDNA apparent re-solubilization. During the ultrafiltration operation high plasmid retention with low adsorption was obtained under low ionic strength conditions. The results also show that a significant removal proteins and the re-solubilized gDNA is achieved, as well as some purification in respect to low molecular weight RNA, since all these components permeate through the ultrafiltration membrane

Assessing the role played by meteorological conditions on the interannual variability of fire activity in four subregions of Iberia

The Iberian Peninsula is recurrently affected by severe wildfires resulting from an interplay of human activities, landscape features and atmospheric conditions. Aims. The role played by atmospheric conditions on wildfire activity in 2001–2020 is assessed in four pyror- egions of the Iberian Peninsula. Methods. Wildfire activity is characterised by Fire Radiative Power (FRP) and meteorological danger is rated by the Fire Weather Index (FWI). The distribution of log 10 FRP in each pyroregion consists of a truncated lognormal central body with Generalised Pareto distributions as tails, and the model is improved using FWI as covariate. Synthetic time series of total annual FRP are generated using the models with and without FWI as covariate, and compared against observed FRP. Key results. Pyroregions NW, N, SW and E present increases of 1, 5, 6 and 7% in interannual explained variance of FRP when progressing from the model without to that with FWI as covariate. Conclusions. The models developed characterise the role of meteorological conditions on fire activity in the Iberian Peninsula, and are especially valuable when comparing expected impacts for different scenarios of climate change. Implications. The largest effects of atmospheric conditions on fire activity are in regions of the IP where the strongest impact of climate change is expectedinfo:eu-repo/semantics/publishedVersio

Shallow reef fish communities of South Bahia coast, Brazil

Este trabalho descreve pela primeira vez as comunidades de peixes em cinco recifes rasos de Santa Cruz de Cabrália e Porto Seguro (Araripe-AR, Itacipanema-IT, Alagados-AL, Naufrágio-NA e Recife de Fora Marine Park-RF), sul da Bahia, nordeste do Brasil. A densidade e riqueza foram obtidas utilizando censos estacionários de 2 m de raio para espécies pequenas e criptobênticas e 3 m de raio para espécies conspícuas. Um total de 1802 peixes pertencentes a 23 famílias e 54 espécies foram registrados, sendo as espécies mais abundantes dos pomacentrídeos Stegastes fuscus e Abudefduf saxatilis. Nenhuma diferença significativa foi encontrada para a riqueza entre os recifes e também para a densidade de espécies vágeis. Entretanto, a densidade de espécies criptobênticas foi mais alta em lugares com maior rugosidade. Herbívoros foram dominantes nos recifes AR, AL e RF, invertívoros em AL e a dominância dos dois grupos ocorreram em IT. Algumas variáveis ambientais como rugosidade e cobertura bentônica estão fortemente relacionadas às espécies e diferentes recifes. Estes são fisicamente heterogêneos, mas a composição e riqueza de espécies similares, o que seria esperado em comunidades recifais abrangendo estudos em pequena-escala, pois peixes recifais estão amplamente distribuídos.This study aims to describe for the first time the fish community structure of five shallow reefs located off the cities of Santa Cruz de Cabrália and Porto Seguro (Araripe-AR, Itacipanema-IT, Alagados-AL, Naufrágio-NA and Recife de Fora Marine Park-RF Reefs), South Bahia, Northeastern Brazil. Fish density and richness were assessed through stationary point counts of 2 m radius for small cryptic species and 3 m for more conspicuous species. A total of 1 802 fishes belonging to 23 families and 54 species were observed. The most abundant species were the pomacentrids Stegastes fuscus and Abudefduf saxatilis. No significant differences were found for species richness or density of conspicuous species, but density of small cryptic species was low on reefs with high bottom rugosity, where there were more holes and crevices available. Herbivores were dominant on AR, AL and RF, invertivores on AL and both groups were dominant on IT. Some habitat variables such as rugosity and benthic cover were strongly correlated to species and sites. High bottom heterogeneity was found among reefs but they still presented similar species composition, richness and density. Within small-scale studies, such similarities in composition and richness are to be expected for reef fish communities, as most of the species concerned have a wide distribution range

Georeferenced analysis of urban nightlife and noise based on mobile phone data

Urban environments are characterized by a complex soundscape that varies across different periods and geographical zones. This paper presents a novel approach for analyzing nocturnal urban noise patterns and identifying distinct zones using mobile phone data. Traditional noise-monitoring methods often require specialized equipment and are limited in scope. Our methodology involves gathering audio recordings from city sensors and localization data from mobile phones placed in urban areas over extended periods with a focus on nighttime, when noise profiles shift significantly. By leveraging machine learning techniques, the developed system processes the audio data to extract noise features indicative of different sound sources and intensities. These features are correlated with geographic location data to create comprehensive city noise maps during nighttime hours. Furthermore, this work employs clustering algorithms to identify distinct noise zones within the urban landscape, characterized by their unique noise signatures, reflecting the mix of anthropogenic and environmental noise sources. Our results demonstrate the effectiveness of using mobile phone data for nocturnal noise analysis and zone identification. The derived noise maps and zones identification provide insights into noise pollution patterns and offer valuable information for policymakers, urban planners, and public health officials to make informed decisions about noise mitigation efforts and urban development.This work was supported by the Fundação para a Ciência e Tecnologia under Grant [UIDB/00315/2020]; and by the project “BLOCKCHAIN.PT (RE-C05-i01.01—Agendas/Alianças Mobilizadoras para a Reindustrialização, Plano de Recuperação e Resiliência de Portugal” in its component 5—Capitalization and Business Innovation and with the Regulation of the Incentive System “Agendas for Business Innovation”, approved by Ordinance No. 43-A/2022 of 19 January 2022)

Plasmid DNA/RNA separation by ultrafiltration: modeling and application study

RNA is one of the main soluble contaminants that needs to be separated from plasmid DNA (pDNA) during its recovery process from fermentation broths. Although significantly different in molecular size, pDNA and RNA are difficult to separate by membrane filtration due to the fact that both types of molecules are highly deformable and therefore suffer flow-induced elongation when permeating through porous membranes. The possibility of performing this separation by ultrafiltration is investigated here with the aid of a theoretical model describing the interactions between two electrically charged, flexible macromolecules that simultaneously permeate through a porous membrane. The results of the simulations, applied to pDNA and the different types of RNA present in cell lysates under typical process conditions, show that only by a careful choice of the membrane pore size and the imposed permeate flux one can achieve the required selectivity in this operation. Ultrafiltration tests using microfiltered lysates from the production of two different plasmids, pVAX1-LacZ (6050 bp) and pCAMBIA-1303 (12,361 bp), were carried out to check the validity of the theoretical predictions; the experimental results confirm these predictions and the idea that this technique can be used in practice for pDNA purification.Fundação para a Ciência e a Tecnologia (FCT