Geração de números verdadeiramente aleatórios baseados em ruído quântico

Quantum Random Number Generators (QRNGs) promise information-theoretic security by exploring the intrinsic probabilistic properties of quantum mechanics. In practice, their security frequently relies on a number of assumptions over physical devices. In this thesis, a randomness generation framework that explores the amplitude quadrature fluctuations of a vacuum state was analyzed. It employs a homodyne measurement scheme, which can be implemented with low-cost components, and shows potential for high performance with remarkable stability. A mathematical description of all necessary stages was provided as security proof, considering the quantization noise introduced by the analog-to-digital converter. The impact of experimental limitations, such as the digitizer resolution or the presence of excess noise due to an unbalanced detection, was characterized. Moreover, we propose a framework to estimate the excess entropy introduced by an unbalanced detection, and its high impact within the Shannon entropy model was experimentally verified. Furthermore, a real-time dedicated QRNG scheme was implemented and validated. The variance characterization curve of the homodyne detector was measured, and the quantum fluctuations were determined to be preponderant for an impinging power PLO < 45.7mW. By estimating the worst-case min-entropy conditioned on the electronic noise, approximately 8.39 true random bits can be extracted from each sample, yielding a maximum generation rate of 8.23 Gbps. With a lengthcompatible Toeplitz-hashing algorithm, these can be extracted at 75 Mbps with an upper security bound of 2−105, which illustrates the quality of this implementation. Moreover, the generation scheme was validated and verified to pass all the statistical tests of the NIST, DieHarder, and TestU01’s SmallCrush batteries, as well as most of TestU01’s Crush evaluations. Finally, we propose a framework for time-interleaving the entropy source within a classical communication channel, which removes the need for a dedicated generation device. After assessing the conditions where quantum noise is dominant, support for generation rates up to 1.3 Gbps was observed. The random bitstream was subjected to the NIST randomness test suite and consistently passed all evaluations. Moreover, a clean quadrature phase shift keying constellation was recovered, which supports the multi-purpose function of the scheme.Geradores quânticos de números aleatórios (QRNGs) prometem sistemas informação-teoricamente seguros explorando as propriedades intrinsecamente probabilísticas da mecânica quântica. No entanto, experimentalmente, um conjunto de pressupostos é tipicamente imposto sobre os dispositivos experimentais. Nesta dissertação, analisou-se uma abordagem para geração de números aleatórios que explora as flutuações de amplitude em quadratura de um estado vácuo. Para tal, recorre-se a um esquema de deteção homodina que permite um elevado desempenho e estabilidade, requerendo apenas dispositivos de baixo custo. Um modelo matemático das diferentes etapas do gerador foi desenvolvido de forma a fornecer uma prova de segurança, e contabilizou-se o ruído de discretização introduzido pelo conversor analógico-digital. Adicionalmente, caracterizou-se o impacto de imperfeições experimentais como a resolução do conversor analógico-digital e a presença de ruído em excesso como consequência de uma deteção não balanceada. Uma abordagem para estimar esta contribuição no modelo de entropia de Shannon foi também proposta e experimentalmente verificada. Adicionalmente, uma implementação em tempo-real foi caracterizada. A curva de caracterização do detetor homodino foi experimentalmente verificada, e uma preponderância de ruído quântico observado para potências óticas inferiores a 45.7mW. Através de uma estimativa da min-entropy condicionada ao ruído eletrónico, aproximadamente 8.39 bits por medição podem ser extraídos, o que corresponde a uma taxa de geração máxima de 8.23 Gbps. Estes podem ser extraídos a uma taxa de 75 Mbps com um parâmetro de segurança de 2−105, ilustrativo da qualidade desta implementação, através de um algoritmo eficiente de multiplicação de matrizes de Toeplitz. Posteriormente, o esquema foi validado, passando todos os testes estatísticos das baterias NIST, DieHarder, e SmallCrush, assim como a maioria das avaliações contidas na bateria Crush. Por último, foi proposta uma abordagem para integrar esta fonte de entropia num canal de comunicação clássico, removendo desta forma a necessidade de uma implementação dedicada. Após avaliação das condições de preponderância do ruído quântico, foram observadas taxas de geração até 1.3 Gbps. Os números obtidos foram também submetidos à bateria de testes do NIST, passando consistentemente todas as avaliações. Adicionalmente, a constelação de modulação de amplitude em quadratura obtida viabiliza a operação multifuncional do sistema.Mestrado em Engenharia Físic

Tissue culture applied to carnivorous species

The purpose of the review is to comment on available data on the application of plant tissue culture to carnivorous plants. Thus, the review encompassed publications from 1979 to 2017 along in vitro germination studies and micropropagation techniques, such as somatic embryogenesis and organogenesis, which emphasized the responses of plant materials to the stimuli offered during in vitro culture. Tissue culture in carnivorous plants is presented as a tool to promote the increase of the population of these plants either for scientific and commercial purposes or for the conservation and reintroduction in their natural habitat, in order to ensure a sustainable exploitation of this nutritional pattern of plants. In general terms, the studies carried out were limited to the following aspects: cultivation technique, explant source, exogenously applied substances and culture medium. The review also revealed the absence of defined protocols for in vitro multiplication of large-scale carnivorous plants

Brazilian red propolis: extracts production, physicochemical characterization, and cytotoxicity profile for antitumor activity

Brazilian red propolis has been proposed as a new source of compounds with cytotoxic activity. Red propolis is a resinous material of vegetal origin, synthesized from the bees of the Appis mellifera family, with recognized biological properties. To obtain actives of low polarity and high cytotoxic profile from red propolis, in this work, we proposed a new solvent accelerated extraction method. A complete 23 factorial design was carried out to evaluate the influence of the independent variables or factors (e.g., temperature, number of cycles, and extraction time) on the dependent variable or response (i.e., yield of production). The extracts were analyzed by gas chromatography coupled with mass spectrometry for the identification of chemical compounds. Gas chromatography analysis revealed the presence of hydrocarbons, alcohols, ketones, ethers, and terpenes, such as lupeol, lupenone, and lupeol acetate, in most of the obtained extracts. To evaluate the cytotoxicity profile of the obtained bioactives, the 3-(4,5-dimethyl-2-thiazole)-2,5-diphenyl-2-H-tetrazolium bromide colorimetric assay was performed in different tumor cell lines (HCT116 and PC3). The results show that the extract obtained from 70 °C and one cycle of extraction of 10 min exhibited the highest cytotoxic activity against the tested cell lines. The highest yield, however, did not indicate the highest cytotoxic activity, but the optimal extraction conditions were indeed dependent on the temperature (i.e., 70 °C).FCT -Fundação para a Ciência e a Tecnologia(UIDB/04469/2020)info:eu-repo/semantics/publishedVersio

[Covid-19 in the Northeast of Brazil: from lockdown to the relaxation of social distancing measures].

Even in the period when the Covid-19 pandemic was on the rise in the Northeast of Brazil, the relaxation of social distancing measures was introduced. The scope of the study is to assess, in the light of the epidemiological-sanitary situation in the region, the suitability of relaxation of social distancing measures. Based on the WHO guidelines for relaxation of social distancing, operational indicators were created and analyzed for each guideline in the context of the Northeast. To analyze the behavior of the epidemic, according to selected indicators, Joinpoint trend analysis techniques, heat maps, rate ratios and time trends between capitals and the state interior were compared. The weekly growth peak of the epidemic occurred in May-July 2020 (epidemiological weeks 19 to 31). In most capitals, there was no simultaneous downward trend in the number of cases and deaths in the 14 days prior to flexibilization. In all states the number of tests performed was insufficient. In epidemiological week 24, the state percentages of ICU/Covid-19 bed occupancy were close to or above 70%. The epidemiological situation of the nine Northeastern state capitals analyzed here did not meet criteria and parameters recommended by the World Health Organization for the relaxation of social distancing measures

SARS-CoV-2 introductions and early dynamics of the epidemic in Portugal

Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARSCoV-2 introductions and early dissemination in Portugal. Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland), which were consistent with the countries with the highest connectivity with Portugal. Although most introductions were estimated to have occurred during early March 2020, it is likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the first cases were confirmed. Conclusions Here we conclude that the earlier implementation of measures could have minimized the number of introductions and subsequent virus expansion in Portugal. This study lays the foundation for genomic epidemiology of SARS-CoV-2 in Portugal, and highlights the need for systematic and geographically-representative genomic surveillance.We gratefully acknowledge to Sara Hill and Nuno Faria (University of Oxford) and Joshua Quick and Nick Loman (University of Birmingham) for kindly providing us with the initial sets of Artic Network primers for NGS; Rafael Mamede (MRamirez team, IMM, Lisbon) for developing and sharing a bioinformatics script for sequence curation (https://github.com/rfm-targa/BioinfUtils); Philippe Lemey (KU Leuven) for providing guidance on the implementation of the phylodynamic models; Joshua L. Cherry (National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health) for providing guidance with the subsampling strategies; and all authors, originating and submitting laboratories who have contributed genome data on GISAID (https://www.gisaid.org/) on which part of this research is based. The opinions expressed in this article are those of the authors and do not reflect the view of the National Institutes of Health, the Department of Health and Human Services, or the United States government. This study is co-funded by Fundação para a Ciência e Tecnologia and Agência de Investigação Clínica e Inovação Biomédica (234_596874175) on behalf of the Research 4 COVID-19 call. Some infrastructural resources used in this study come from the GenomePT project (POCI-01-0145-FEDER-022184), supported by COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and by Fundação para a Ciência e a Tecnologia (FCT).info:eu-repo/semantics/publishedVersio

The Genome of Anopheles darlingi, the main neotropical malaria vector

Anopheles darlingi is the principal neotropical malaria vector, responsible for more than a million cases of malaria per year on the American continent. Anopheles darlingi diverged from the African and Asian malaria vectors ∼100 million years ago (mya) and successfully adapted to the New World environment. Here we present an annotated reference A. darlingi genome, sequenced from a wild population of males and females collected in the Brazilian Amazon. A total of 10 481 predicted protein-coding genes were annotated, 72% of which have their closest counterpart in Anopheles gambiae and 21% have highest similarity with other mosquito species. In spite of a long period of divergent evolution, conserved gene synteny was observed between A. darlingi and A. gambiae. More than 10 million single nucleotide polymorphisms and short indels with potential use as genetic markers were identified. Transposable elements correspond to 2.3% of the A. darlingi genome. Genes associated with hematophagy, immunity and insecticide resistance, directly involved in vectorhuman and vectorparasite interactions, were identified and discussed. This study represents the first effort to sequence the genome of a neotropical malaria vector, and opens a new window through which we can contemplate the evolutionary history of anopheline mosquitoes. It also provides valuable information that may lead to novel strategies to reduce malaria transmission on the South American continent. The A. darlingi genome is accessible at www.labinfo.lncc.br/index.php/anopheles- darlingi. © 2013 The Author(s)

The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

Climate seasonality limits leaf carbon assimilation and wood productivity in tropical forests

The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter productivity measurements), their associated canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonality in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positively to precipitation when rainfall is  < 2000 mm yr⁻¹ (water-limited forests) and to radiation otherwise (light-limited forests). On the other hand, independent of climate limitations, wood productivity and litterfall are driven by seasonal variation in precipitation and evapotranspiration, respectively. Consequently, light-limited forests present an asynchronism between canopy photosynthetic capacity and wood productivity. First-order control by precipitation likely indicates a decrease in tropical forest productivity in a drier climate in water-limited forest, and in current light-limited forest with future rainfall  < 2000 mm yr⁻¹

Congenital Secondary Hypothyroidism Evidences in a Dog

Background: Deficiency of thyroid hormones thyroxine (T4) and triiodothyronine (T3) results in multisystemic disease described as hypothyroidism (HpoT). Secondary HpoT is defined by TSH decreased production and, therefore, thyroid hormones. This condition is rare in dogs, accounting for less than 5% of cases. The objective of this report is to describe evidence of congenital secondary hypothyroidism in a mongrel dog and therapeutic response obtained.Case: A 3-year-old neutered male mongrel dog was brought to the veterinarian with a history of overweight without polyphagia, associated with discrete alopecia, poor quality skin and hair coat, lethargy and evident exercise intolerance. Physical examination revealed a body condition score of seven (1 to 9 scale), disqueratosis, pyoderma, ventral cervical alopecia, hair thinning on the posterior surface of the pelvic limbs and nonpalpable thyroid. A body conformation characterized by disproportionate dwarfism was observed. Owners provided a former patient´s X-ray (18 months of age), showing growth plate non-closure in vertebral bodies. Results of a complete blood count (CBC) and serum biochemical profile were within normal limits except for elevated fructosamine (459 µmol/L; reference range: 170-338 µmol/L) and total cholesterol (558 mg/dL; reference range: 135-270 mg/dL). Analyses of the hormone profile showed decreased levels of canine thyroid-stimulating hormone (cTSH) 0.03 ng/mL (reference range: 0.05-0.5 ng/mL), free thyroxine by equilibrium dialysis (fdT4) 0.57 ng/dL (reference range: 0.8-3.0 ng/dL), and total thyroxine (tT4) 5.1 ng/mL (reference range: 15-30 ng/mL). A distal forelimb X-ray was performed and showed opened epiphyseal growth plates from radius and ulnar bones. The patient was discharged with sodium levothyroxine (20 µg/kg PO q 24 hr) until re-evaluation. The patient was re-evaluated 2 months later and clinical symptoms observed at the first admission were still persistent. CBC and serum biochemical profile were within normal range. The values of T4t and cTSH were 21.3 ng/mL (reference range for treated dogs 25-45 ng/mL post-thyroxine) and 0.03 ng/mL respectively. Owners were administering a generic levothyroxine, and then a commercial sodium levothyroxine was prescribed at the same dose for treatment. Clinical improvement was reported by the owner 4 weeks later. A new forelimb and vertebral radiographic examination performed 6 months later revealed complete epiphyseal ossification.Discussion: The patient was diagnosed with central hypothyroidism based on the clinical presentation in conjunction with the laboratory tests results. The main hypothesis argues for a congenital pituitary malformation, leading to a defective hypothalamic-pituitary-thyroid axis function. This decreased hormonal TSH secretion culminated in a chronic mild state of hypothyroidism associated with reduction in the thyroid hormones secretion. Metabolic consequences of mild hypothyroidism affect bone development directly and lead to delayed epiphyseal ossification and epiphyseal growth, reduced long bone growth, and disproportionate dwarfism. Studies have suggested a genetic relation with the development of congenital hypothyroidism, although no disease-causing mutations were found in the genes previously investigated. The prognosis for dogs with secondary hypothyroidism due to malformation or destruction of the pituitary ranges from poor to reserved, with shorter life expectancy in dogs with congenital pituitary malformation due to cysts expansion. Although cost is limiting for some owners, advanced imaging such as computed tomography or magnetic resonance may be useful in the macroscopic evaluation of the pituitary gland and are recommended in central hypothyroidism cases