A Switched-Capacitor Band-Pass Biquad Filter Using a Simple Quasi-unity Gain Amplifier

Part 19: Electronics: AmplifiersInternational audienceThis paper presents a switched-capacitor (SC) band-pass biquad using a simple quasi-unity gain amplifier. In sub-nanometer CMOS technologies the intrinsic gain of the transistors is low; this increases the difficulty of designing high gain amplifiers. The proposed SC filter is based on the Sallen-Key biquad and it requires only a simple low gain amplifier. A differential filter circuit, including a suitable amplifier based on a fully-differential voltage-combiner is presented and analyzed. The correct functionality of this circuit is validated through electrical simulations of a second-order band-pass filter. These simulations show that, for a clock frequency of 100 MHz, the frequency response of the circuit is similar to the corresponding prototype filter

Espaços Verdes Urbanos e as Percepções Globais dos Serviços Ecossistêmicos à Luz da Tecnologia

Intensos processos de extensão e modificação urbana refletiram na normalização da habitabilidade de ambientes adversos, hostis e/ou insalubres e alterações significativas dos serviços ecossistêmicos. Por isso é urgente a transição da sociedade e dos ambientes urbanos para um modelo pautado nos princípios da sustentabilidade. O trabalho tem como objetivo analisar em escala global a importância dos serviços ecossistêmicos para a sustentabilidade das cidades e seus habitantes e compreender o uso de diferentes metodologias para a percepção, o planejamento e a gestão desses serviços em grandes centros urbanos. A metodologia consistiu em análise bibliométrica a partir do uso da plataforma SCOPUS, com o mecanismo de busca definido por artigo e review e trabalhos publicados em inglês ou espanhol. A gestão bibliográfica foi realizada no software Mendeley e as redes semânticas foram estabelecidas no VOSviewer. Observou-se um grande volume de trabalhos publicados, com destaque para Estados Unidos, China e Reino Unido, assim com Alemanha e Austrália. Foi constatado também a presença de múltiplas metodologias de análise que vão desde aptidão lúdica ao uso de realidade virtual e imagens de satélite

Hop bioactive compounds: spontaneous vs commercial varieties

Humulus lupulus L. is a species belonging to the Cannabaceae family. Hop, as it is commonly known, is a perennial, dioecious and normally diploid (2n = 20) herbaceous plant. It is in beer production that hops have their greatest economic value at the international level. In addition, Hops contain compounds that confer sedative, diuretic anti-inflammatory and antiarthritic properties. In fact, the ethnobotanical uses of the dried flowers in pillows called "hop pads" have been used to combat insomnia while the dried and green hop inflorescences , were used in the Montesinho park area to treat urinary and digestive disorders. Since the middle Ages, it was used in infusions as a tonic; it was considered a medicinal herb. Since there is spontaneous hops in a large part of Portugal, the collection and analysis of the aromas the α and β-acids component, and phenols of these hops may lead to the development of new and more fragrances, with interest in different areas, like beer production or cosmetics. The volatile components extracted from spontaneous hops collected in the Bragança area were analyzed and compared with those of commercial varieties. The results obtained show a certain similarity in the monoterpene component, with β-myrcene as the major compound (more than 64% in cultivar and spontaneous samples) and notorious differences in the sesquiterpene component, evident in cases of α-humulene (12% in cultivars, 0.2% and in spontaneous) and trans-β-farnesene (not detected in cultivars, 9% in spontaneous). Also important is the richness of the sesquiterpene component in spontaneous clone, in particular in the oxygenated compounds. This profile, of both cultivar and spontaneous, shows potential for antimicrobial effects in the digestive tract, especially when these are associated with bacteria Helicobacter pylori, which will be in agreement with ethnobotanical uses of Hop. The higher values, in the cultivars, of the α and β-acids component is expected since the Nugget cultivar is characterized by a bitter taste, due to acids, whereas the aroma cultivars, which are more required by the artisan brewers, are valued for their richness in aromas (essential oils), the richness of the spontaneous in trans-β-farnesene being determinant to the stability of the beer, or used in cosmetic products.info:eu-repo/semantics/publishedVersio

Estudo cromatográfico de compostos bioactivos em cultivares e espontâneos de lúpulo

Estudo cromatográfico de compostos bioactivos em cultivares e espontâneos de lúpulo Humulus lupulus L. é uma espécie da família Cannabaceae. O Lúpulo é uma planta herbácea, perene, dióica e geralmente diploide (2n = 20). É na produção de cerveja que o lúpulo tem seu maior valor económico a nível internacional, ganhando uma nova projeção recentemente, devido ao aumento da indústria cervejeira artesanal. Devido à produção de compostos com ação bactericida, particularmente contra bactérias Gram-negativas, o lúpulo A demanda por novos aromas aumentou, impulsionada pela expansão da produção de cerveja artesanal em Portugal. Há lúpulos espontâneos em todo o país e a coleta e análise dos aromas desses lúpulos pode levar ao desenvolvimento de variedades novas e mais aromáticas. Sendo a zona de Bragança rica em lúpulos espontâneos, os extractos voláteis e α e β ácidos de lúpulo espontâneo na região de Bragança (Trás-os-Montes) foram analisados e comparados com variedades comerciais (Nugget, Cascate e Chinouke). As amostras foram colhidas em diferentes áreas do distrito de Bragança. Os voláteis foram extraídos dos cones femininos, usando um sistema Likens-Nickerson, e analisados por GC e GC-MS. Os ácidos α e β, de variedades e espontâneos, foram extraídos e analisados por HPLC. Nugget (amargo) e clone espontâneo mostraram semelhanças na componente monoterpenica, com β-mirceno como principal composto (75 e 64%, respectivamente nas cultivares Nugget e espontânea) e diferenças significativas na componente sesquiterpenica, (12% cultivar, 0,2% espontânea) e trans-β-farneseno (não detectado na cultivar Nugget e 9% na espontânea). Destaca-se a maior riqueza da fração sesquiterpênica do clone espontâneo, em especial nos compostos oxigenados. Em relação às análises por HPLC, duas amostras da mesma variedade de cultivares (Nugget), de sítios distintos, foram comparadas com uma amostra de uma amostra espontânea. As cultivares apresentaram valores totais de 12,12% e 14,33% de α-ácidos e 3,31% e 3,99% de β, respectivamente, enquanto a variedade espontânea apresentou 5,35% de α-ácidos e 4,3% de β-ácidos. Os maiores valores, nas cultivares, do componente α e β-ácidos são esperados, uma vez que a cultivar Nugget é caracterizada por um sabor amargo, devido aos ácidos, enquanto que as cultivares aromáticas, mais procuradas pelos fabricantes de cerveja, são valorizadas, pela sua riqueza em aromas (óleos essenciais), por outro lado a riqueza em trans-β-farneseno é determinante, uma vez que é um antioxidante muito importante que pode ter uma boa contribuição para a estabilidade da cerveja.info:eu-repo/semantics/publishedVersio

Voláteis, α e β- ácidos em lúpulo: um estudo da planta à cerveja

Da família Cannabaceae o Humulus lupulus L., produz compostos com ação bactericida, particularmente contra bactérias Gram-negativas e de ter aumentado a demanda por novos aromas, fez com que o lúpulo fosse cada vez mais estudado. [1] Os extratos voláteis e α e β ácidos de lúpulo espontâneo na região de Bragança foram comparados com variedades comerciais (Nugget, Cascade, Chinooke e Centennial). Os voláteis extraídos do lúpulo (cones femininos, partes vegetativas e pellets) usando o sistema LikensNickerson, e analisados por GC e GC-MS. Os ácidos α e β, foram extraídos e analisados por HPLC. As amostras de cervejas que foram testadas, pela metodologia LN, das quais obtivemos dados não conclusivos com 90% de níveis de álcoois, desta forma a metodologia será alterada de forma a obtermos dados mais precisos. As amostras tem semelhanças na componente monoterpenica, com β-mirceno como principal composto (na variedade Cascade 61,4% e valores parecidos nas pellets, na parte vegetativa é que foram reduzidos, em Nugget e Centennial os valores formam idênticos e na variedade Chinook obteve-se valores mais baixos) e trans-βfarneseno (9% na espontânea, em Cascade foi detetado 3,7% nos cones e 4,7% nas pellets, não detetado na cultivar Nugget). Nas análises por HPLC, a amostra de lúpulo espontâneo apresentaram valores totais de ácidos α e β 7,30% e de 8,60%, já na variedade Nugget apresenta valores médios de 13,27 % e 3,65% , na variedade Cascade (flor) de 4,53% e 5,63% semelhante nas pellets já em relação a variedade Chinook flor 14,4% e 4,58% nas pellets 9,25% e 3,01% e nas amostras Centennial (pellets) de 7,07% e 3,14%. Palavras chave: lúpulo , ácidos α e β, compostos voláteis, espontâneos, cultivares [1] Heale J. B., Legg T., Brar J., Fabb A., Bainbridge B., (1989) Application of plant tissue culture and molecular biology techniques to “progressive” wiltof hops caused by Verticillium albo-atrum. Eur. Brew. Conv. Monogr., XV, Symposium on Plant Biotechnology,info:eu-repo/semantics/publishedVersio

Estudo cromatográfico de compostos bioativos em cultivares e espontâneos de lúpulo

Estudo cromatográfico de compostos bioactivos em cultivares e espontâneos de lúpulo Humulus lupulus L. é uma espécie da família Cannabaceae. O Lúpulo é uma planta herbácea, perene, dióica e geralmente diploide (2n = 20). É na produção de cerveja que o lúpulo tem seu maior valor económico a nível internacional, ganhando uma nova projeção recentemente, devido ao aumento da indústria cervejeira artesanal. Devido à produção de compostos com ação bactericida, particularmente contra bactérias Gram-negativas, o lúpulo A demanda por novos aromas aumentou, impulsionada pela expansão da produção de cerveja artesanal em Portugal. Há lúpulos espontâneos em todo o país e a coleta e análise dos aromas desses lúpulos pode levar ao desenvolvimento de variedades novas e mais aromáticas. Sendo a zona de Bragança rica em lúpulos espontâneos, os extractos voláteis e α e β ácidos de lúpulo espontâneo na região de Bragança (Trás-os-Montes) foram analisados e comparados com variedades comerciais (Nugget, Cascate e Chinouke). As amostras foram colhidas em diferentes áreas do distrito de Bragança. Os voláteis foram extraídos dos cones femininos, usando um sistema Likens-Nickerson, e analisados por GC e GC-MS. Os ácidos α e β, de variedades e espontâneos, foram extraídos e analisados por HPLC. Nugget (amargo) e clone espontâneo mostraram semelhanças na componente monoterpenica, com β-mirceno como principal composto (75 e 64%, respectivamente nas cultivares Nugget e espontânea) e diferenças significativas na componente sesquiterpenica, (12% cultivar, 0,2% espontânea) e trans-β-farneseno (não detectado na cultivar Nugget e 9% na espontânea). Destaca-se a maior riqueza da fração sesquiterpênica do clone espontâneo, em especial nos compostos oxigenados. Em relação às análises por HPLC, duas amostras da mesma variedade de cultivares (Nugget), de sítios distintos, foram comparadas com uma amostra de uma amostra espontânea. As cultivares apresentaram valores totais de 12,12% e 14,33% de α-ácidos e 3,31% e 3,99% de β, respectivamente, enquanto a variedade espontânea apresentou 5,35% de α-ácidos e 4,3% de β-ácidos. Os maiores valores, nas cultivares, do componente α e β-ácidos são esperados, uma vez que a cultivar Nugget é caracterizada por um sabor amargo, devido aos ácidos, enquanto que as cultivares aromáticas, mais procuradas pelos fabricantes de cerveja, são valorizadas, pela sua riqueza em aromas (óleos essenciais), por outro lado a riqueza em trans-β-farneseno é determinante, uma vez que é um antioxidante muito importante que pode ter uma boa contribuição para a estabilidade da cerveja.info:eu-repo/semantics/publishedVersio

Volatiles compounds composition: Stevia field plants in mediterranean conditions, greenhouse plants and plants in vitro

A major concern about public health is the control of obesity. The search for new natural sweeteners, as an alternative to synthetic compounds like cyclamates or aspartame, brought Stevia rebaudiana (Compositae), a sweet plant native to South America, to the attention of the scientific community. S. rebaudiana has been produced mainly for its stevioside compounds but it contains other metabolites with potential therapeutic benefits such as alkaloids, hydroxycinnamic acids, oligosaccharides or essential oils. The characterization of the chemical profile of micropropagated plants, as well as greenhouse and field grown plants, is important to ensure the quality of the plants to supply to Stevia growers. Multiplication rate and fresh weight were determined for plants micropropagated in MS media A with sucrose (20g.L-1) and without growth regulators and MS media B with kinetin (0.5mg.L-1) and sucrose (20g.L-1). Apart from spontaneous rooting rate determination, induction of plant rooting by auxin shock, using IBA (2mg.mL-1), was also evaluated. Acclimatization in greenhouse was performed with hydro atomization nozzles working every 10 minutes. Plants on the field were fertilized by a nutrient solution with N, P2O5, K2O and B. In vitro multiplication rate was 300% per month, fresh weigh after a 4 week subculture was 0.9g. Spontaneous rooting rate was less than 4% after 4 months but induced rooting achieved 30% of plants with developed root system after 1 week and 70% after 2 weeks. Acclimatization rate was 100% after 2 weeks. Acclimatization was performed in greenhouse with 360º hidroatomizing spires working each 10 minutes and the acclimation rate in the greenhouse was of 100% for both medium after 2 weeks. There were extraction of essential oils with Clevenger apparatus for Yield purposes with average yield values below 0.6 %. In Clevenger, six samples were from Vilariça region and two from micro propagation, one was MS medium without growth regulators and the other was MS medium with 0.5 mg/L kinetin. In LN the extractions from four different sources, that are represented in figure 6. The essential oil identification was between 75,5 and 83% for the three samples and the results are not very different in the compounds. Volatiles identification revealed identical composition in all samples, with α-pinene (11-31%), bicyclogermacrene (5 19%), trans-β-farnesene (7-15%), β-elemene (6-10%) and β-caryophyllene (3-10%) as major compounds. Cultivated Stevia shows the higher value in the sequiterpenes hydrocarbons (54,4%), oxygen-contaning monoterpenes (3,2%) and oxygen-contaning sequiterpenes (7,1%). In vitro Stevia Media A and B the value are only very different in monoterpene hydrocarbons and other compounds, but the other value are very similar or exactly the same. In general cultivated and greenhouse. Stevia have higher values for sequiterpenes and the in vitro Stevia have higher values for monoterpenes.The authors are grateful to strategic project PRODER nº 46025 - Gestão Sustentável da Produção de Plantas Aromáticas e Medicinais, and PRODER nº 46207 - Adaptação cultural de hortelã-vulgar e Stévia. This study was partially funded also by FCT, under UID/AMB/50017/2013.info:eu-repo/semantics/publishedVersio

Stevia rebaudiana: a study in the volatiles profile from plants grown in the field in the greenhouse and micropropagated in vitro

Stevia rebaudiana Bertoni leaves are natural sources of steviol glycosides, which are used commercially for sweetening and flavouring foods and beverages. Steviol glycosides are natural sweeteners constituting an alternative to synthetic compounds like cyclamates or aspartame. S. rebaudiana has been produced mainly for its stevioside compounds but it contains other metabolites with potential therapeutic benefits such as alkaloids, hydroxycinnamic acids, oligosaccharides or essential oils. The chemical profile of samples development by micropropagation or in green house or in field conditions, should be characterized to ensure the quality of the samples supplied by Stevia producers. Multiplication rate and fresh weight were determined for plants micropropagated in two different culture media (medium A - Murashige and Skoog (MS) without hormones and sucrose), (medium B - MS with 0.5 mg.L-1 of kinetin and 20 g.L-1of sucrose). Apart from spontaneous rooting rate determination, induction of plant rooting by auxin shock, using indole-3-butyric acid (IBA) (2 mg.mL-1), was also evaluated. Acclimatization in greenhouse was performed with hydro atomization nozzles working every 10 minutes. Plants on the field were fertilized by a nutrient solution with N, P2O5, K2O and B. The essential oil yield was determined for plants in all conditions (in vitro, greenhouse, field) using a Clevenger-type apparatus. Volatiles were isolated using a Likens-Nickerson apparatus and analyzed by GCMS. The in vitro multiplication rate was 300% per month and the fresh weight after a 4 week subculture was 0.9 g. Spontaneous rooting rate was less than 4% after 4 months but induced rooting achieved 30% of plants with developed root system after 1 week and 70% after 2 weeks. Acclimatization rate was 100% after 2 weeks. The essential oil yield was <0.06% for all samples. Volatiles identification revealed identical composition in all samples, with α-pinene (11-31%), bicyclogermacrene (5‑19%), trans-β-farnesene (7-15%), β-elemene (6-10%) and β-caryophyllene (3-10%) as major compounds. Quantitative differences were noteworthy.info:eu-repo/semantics/publishedVersio

Verbal and Visual Memory Impairments Among Young Offspring and Healthy Adult Relatives of Patients With Schizophrenia and Bipolar Disorder: Selective Generational Patterns Indicate Different Developmental Trajectories

Objective: Memory deficits have been shown in patients affected by schizophrenia (SZ) and bipolar (BP)/mood disorder. We recently reported that young high-risk offspring of an affected parent were impaired in both verbal episodic memory (VEM) and visual episodic memory (VisEM). Understanding better the trajectory of memory impairments from childhood to adult clinical status in risk populations is crucial for early detection and prevention. In multigenerational families densely affected by SZ or BP, our aim was to compare the memory impairments observed in young nonaffected offspring with memory functioning in nonaffected adult relatives and patients. Methods: For 20 years, we followed up numerous kindreds in the Eastern Québec population. After having characterized the Diagnostic and Statistical Manual of Mental Disorders phenotypes, we assessed cognition (N = 381) in 3 subsamples in these kindreds and in controls: 60 young offspring of a parent affected by SZ or BP, and in the adult generations, 92 nonaffected adult relatives and 40 patients affected by SZ or BP. VEM was assessed with the California Verbal Learning Test and VisEM with the Rey figures. Results: The VEM deficits observed in the offspring were also found in adult relatives and patients. In contrast, the VisEM impairments observed in the young offspring were present only in patients, not in the adult relatives. Conclusion: Implications for prevention and genetic mechanisms can be drawn from the observation that VEM and VisEM would show distinct generational trajectories and that the trajectory associated with VisEM may offer a better potential than VEM to predict future risk of developing the disease

Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)