1000 resultados para P. alata
Resumo:
In the Bayesian framework a standard approach to model criticism is to compare some function of the observed data to a reference predictive distribution. The result of the comparison can be summarized in the form of a p-value, and it's well known that computation of some kinds of Bayesian predictive p-values can be challenging. The use of regression adjustment approximate Bayesian computation (ABC) methods is explored for this task. Two problems are considered. The first is the calibration of posterior predictive p-values so that they are uniformly distributed under some reference distribution for the data. Computation is difficult because the calibration process requires repeated approximation of the posterior for different data sets under the reference distribution. The second problem considered is approximation of distributions of prior predictive p-values for the purpose of choosing weakly informative priors in the case where the model checking statistic is expensive to compute. Here the computation is difficult because of the need to repeatedly sample from a prior predictive distribution for different values of a prior hyperparameter. In both these problems we argue that high accuracy in the computations is not required, which makes fast approximations such as regression adjustment ABC very useful. We illustrate our methods with several samples.
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We have prepared p-n junction organic photovoltaic cells using an all solution processing method with poly(3-hexylthiophene) (P3HT) as the donor and phenyl-C 61-butyric acid methyl ester (PCBM) as the acceptor. Interdigitated donor/acceptor interface morphology was observed in the device processed with the lowest boiling point solvent for PCBM used in this study. The influences of different solvents on donor/acceptor morphology and respective device performance were investigated simultaneously. The best device obtained had characteristically rough interface morphology with a peak to valley value ∼15 nm. The device displayed a power conversion efficiency of 1.78%, an open circuit voltage (V oc) 0.44 V, a short circuit current density (J sc) 9.4 mA/cm 2 and a fill factor 43%.
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In her album, Hymns of the 49th Parallel, the chanteuse K.D. Lang pays tribute to a series of great Canadian songwriters—such as Neil Young, Leonard Cohen, Joni Mitchell and Jane Siberry. In a similar spirit of celebration, this review essay pays homage to a number of recent texts and films dealing with Canadian intellectual property. First, it considers Ysolde Gendreau’s collection, An Emerging Intellectual Property Paradigm: Perspectives from Canada. Second, this essay looks at Laura Murray and Samuel Trosow’s manual, Canadian Copyright: A Citizen’s Guide. Finally, this review evaluates Brett Gaylor’s documentary, RiP! A Remix Manifesto. The three works share certain affinities—a spirit of scepticism about the legitimacy and the efficacy of existing networks of law, policy and bureaucracy; a populist interest in the impact of intellectual property on the everyday lives of citizens, creators and consumers; a passion for human rights; and a melioristic desire for sensible law reform of copyright law and related regimes of intellectual property.
Resumo:
Sensors to detect toxic and harmful gases are usually based on metal oxides that are operated at elevated temperature. However, enabling gas detection at room temperature (RT) is a significant ongoing challenge. Here, we address this issue by demonstrating that microrods of semiconducting CuTCNQ (TCNQ=7,7,8,8-tetracyanoquinodimethane) with nanostructured features can be employed as conductometric gas sensors operating at 50°C for detection of oxidizing and reducing gases such as NO2 and NH3. The sensor is evaluated at RT and up to 200°C. It was found that CuTCNQ is transformed into a N-doped CuO material with p-type conductivity when annealed at the maximum temperature. This is the first time that such a transformation, from a semiconducting charge transfer material into a N-doped metal oxide is detected. It is shown here that both the surface chemistry and the type of majority charge carrier within the sensing layer is critically important for the type of response towards oxidizing and reducing gases. A detailed physical description of NO2 and NH3 sensing mechanism at CuTCNQ and N-doped CuO is provided to explain the difference in the response. For the N-doped CuO sensor, a detection limit of 1 ppm for NO2 and 10 ppm for NH3 are achieved.
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Objective Child maltreatment is a problem that has longer recognition in the northern hemisphere and in high-income countries. Recent work has highlighted the nearly universal nature of the problem in other countries but demonstrated the lack of comparability of studies because of the variations in definitions and measures used. The International Society for the Prevention of Child Abuse and Neglect has developed instrumentation that may be used with cross-cultural and cross-national benchmarking by local investigators. Design and sampling The instrument design began with a team of expert in Brisbane in 2004. A large bank of questions were subjected to two rounds of Delphi review to develop the fielded version of the instrument. Convenience samples included approximately 120 parent respondents with children under the age of 18 in each of six countries (697 total). Results This paper presents an instrument that measures parental behaviors directed at children and reports data from pilot work in 6 countries and 7 languages. Patterns of response revealed few missing values and distributions of responses that generally were similar in the six countries. Subscales performed well in terms of internal consistency with Cronbach's alpha in very good range (0.77–0.88) with the exception of the neglect and sex abuse subscales. Results varied by child age and gender in expected directions but with large variations among the samples. About 15% of children were shaken, 24% hit on the buttocks with an object, and 37% were spanked. Reports of choking and smothering were made by 2% of parents. Conclusion These pilot data demonstrate that the instrument is well tolerated and captures variations in, and potentially harmful forms of child discipline. Practice implications The ISPCAN Child Abuse Screening Tool – Parent Version (ICAST-P) has been developed as a survey instrument to be administered to parents for the assessment of child maltreatment in a multi-national and multi-cultural context. It was developed with broad input from international experts and subjected to Dephi review, translation, and pilot testing in six countries. The results of the Delphi study and pilot testing are presented. This study demonstrates that a single instrument can be used in a broad range of cultures and languages with low rates of missing data and moderate to high internal consistency.
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Investigation of 31 of Roma patients with congenital lactic acidosis (CLA) from Bulgaria identified homozygosity for the R446* mutation in the PDHX gene as the most common cause of the disorder in this ethnic group. It accounted for around 60% of patients in the study and over 25% of all CLA cases referred to the National Genetic Laboratory in Bulgaria. The detection of a homozygous patient from Hungary and carriers among population controls from Romania and Slovakia suggests a wide spread of the mutation in the European Roma population. The clinical phenotype of the twenty R446* homozygotes was relatively homogeneous, with lactic acidosis crisis in the first days or months of life as the most common initial presentation (15/20 patients) and delayed psychomotor development and/or seizures in infancy as the leading manifestations in a smaller group (5/20 patients). The subsequent clinical picture was dominated by impaired physical growth and a very consistent pattern of static cerebral palsy-like encephalopathy with spasticity and severe to profound mental retardation seen in over 80% of cases. Most patients had a positive family history. We propose testing for the R446* mutation in PDHX as a rapid first screening in Roma infants with metabolic acidosis. It will facilitate and accelerate diagnosis in a large proportion of cases, allow early rehabilitation to alleviate the chronic clinical course, and prevent further affected births in high-risk families.
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Asymmetric tri-bridged diruthenium(III) complexes, [Ru2O(O(2)CR)(3)(en) (PPh(3))(2)](ClO4) (R = C6H4-p-X: X = OMe (1a), Me (1b); en=1,2-diaminoethane), were prepared and structurally characterized. Complex 1a 3CHCl(3), crystallizes in the triclinic space group P (1) over bar with a = 14.029(5), b = 14.205(5), c = 20.610(6) Angstrom, alpha= 107.26(3), beta = 101.84(3), gamma= 97.57(3)degrees, V= 3756(2) Angstrom(3) and Z = 2. The complex has an {Ru-2(mu-O)(mu-O(2)CR)(2)(2+)} core and exhibits [O4PRu(mu-O)RuPO2N2](+) coordination environments for the metal centers. The novel structural feature is the asymmetric arrangement of ligands at the terminal sites of the core which shows an Ru... Ru separation of 3.226(3) Angstrom and an Ru-O-Ru angle of 119.2(5)degrees. An intense visible band observed near 570 nm is assigned to a charge transfer transition involving the d pi-Ru(III) and p pi-mu-O Orbitals. Cyclic voltammetry of the complexes displays a reversible Ru-2(III,III) reversible arrow Ru-2(III,IV) couple near 0.8 V (versus SCE) in MeCN-0.1 M TBAP.
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Poly[(2,5-dimethoxy-p-phenylene)vinylene] (DMPPV) of varying conjugation length was synthesized by selective elimination of organic soluble precursor polymers that contained two eliminatable groups, namely, methoxy and acetate groups. These precursor copolymers were in turn synthesized by competitive nucleophilic substitution of the sulfonium polyelectrolyte precursor (generated by the standard Wessling route) using methanol and sodium acetate in acetic acid. The composition of the precursor copolymer, in terms of the relative amounts of methoxy and acetate groups, was controlled by varying the composition of the reaction mixture during nucleophilic substitution. Thermal elimination of these precursor copolymers at 250 degrees C, yielded partially conjugated polymers, whose color varied from light yellow to deep red. FT-IR studies confirmed that, while essentially all the acetate groups were eliminated, the methoxy groups were intact and caused the interruption in conjugation. Preliminary photoluminescence studies of the partially eliminated DMPPV samples showed a gradual shift in the emission maximum from 498 to 598 nm with increasing conjugation lengths, suggesting that the color of LED devices fabricated from such polymers can, in principle, be fine-tuned.
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The hot deformation behavior of hot isostatically pressed (HIPd) P/M IN-100 superalloy has been studied in the temperature range 1000-1200 degrees C and strain rate range 0.0003-10 s(-1) using hot compression testing. A processing map has been developed on the basis of these data and using the principles of dynamic materials modelling. The map exhibited three domains: one at 1050 degrees C and 0.01 s(-1), with a peak efficiency of power dissipation of approximate to 32%, the second at 1150 degrees C and 10 s(-1), with a peak efficiency of approximate to 36% and the third at 1200 degrees C and 0.1 s(-1), with a similar efficiency. On the basis of optical and electron microscopic observations, the first domain was interpreted to represent dynamic recovery of the gamma phase, the second domain represents dynamic recrystallization (DRX) of gamma in the presence of softer gamma', while the third domain represents DRX of the gamma phase only. The gamma' phase is stable upto 1150 degrees C, gets deformed below this temperature and the chunky gamma' accumulates dislocations, which at larger strains cause cracking of this phase. At temperatures lower than 1080 degrees C and strain rates higher than 0.1 s(-1), the material exhibits flow instability, manifested in the form of adiabatic shear bands. The material may be subjected to mechanical processing without cracking or instabilities at 1200 degrees C and 0.1 s(-1), which are the conditions for DRX of the gamma phase.
Resumo:
Diruthenium (II. III) complexes of the type [Ru-2(O2CAr)(4) (2-mimH)(2)](ClO4) (Ar = C6H4-p-X : X=OMe,1, X=Me, 2, 2-mimH=2-methylimidazole) have been isolated from the reaction of Ru2Cl(O2CAr)(4) with 2-mimH in CH2Cl2 followed by the addition of NaClO4. The crystal structure of 1.1.75CH(2)Cl(2).H2O has been determined. The crystal belongs to the monoclinic space group p2(1)/c with the following unit cell dimensions for the C40H40N4O16ClRu2.1.75CH(2)Cl(2).H2O (M = 1237.0) : a = 12.347(3)Angstrom, b = 17.615(5)Angstrom, c = 26.148(2)Angstrom,beta = 92.88(1)degrees. v = 5679(2)Angstrom(3). Z=4, D-c = 1.45 g cm(-3). lambda(Mo-K-alpha) = 0.7107 Angstrom, mu(Mo-K-alpha) = 8.1 cm(-1), T = 293 K, R = 0.0815 (wR(2) = 0.2118) for 5834 reflections with 1 > 2 sigma(I). The complex has a tetracarboxylatodiruthenium (II, III) core and two axially bound 2-methylimidazole ligands. The Ru-Ru bond length is 2.290(1)Angstrom. The Ru-Ru bond order is 2.5 and the complex is three-electron paramagnetic. The complex shows an irreversible Ru-2(II,III)-->Ru-2(Il,II) reduction near -0.2 V vs SCE in CH2Cl2-0. 1 MTBAP. The complexes exemplify the first adduct of the tetracarboxylatodiruthenium (II,III) core having N-donor ligands
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The bentiromide test was evaluated using plasma p-aminobenzoic acid as an indirect test of pancreatic insufficiency in young children between 2 months and 4 years of age. To determine the optimal test method, the following were examined: (a) the best dose of bentiromide (15 mg/kg or 30 mg/kg); (b) the optimal sampling time for plasma p-aminobenzoic acid, and; (c) the effect of coadministration of a liquid meal. Sixty-nine children (1.6 ± 1.0 years) were studied, including 34 controls with normal fat absorption and 35 patients (34 with cystic fibrosis) with fat maldigestion due to pancreatic insufficiency. Control and pancreatic insufficient subjects were studied in three age-matched groups: (a) low-dose bentiromide (15 mg/kg) with clear fluids; (b) high-dose bentiromide (30 mg/kg) with clear fluids, and; (c) high-dose bentiromide with a liquid meal. Plasma p-aminobenzoic acid was determined at 0, 30, 60, and 90 minutes then hourly for 6 hours. The dose effect of bentiromide with clear liquids was evaluated. High-dose bentiromide best discriminated control and pancreatic insufficient subjects, due to a higher peak plasma p-aminobenzoic acid level in controls, but poor sensitivity and specificity remained. High-dose bentiromide with a liquid meal produced a delayed increase in plasma p-aminobenzoic acid in the control subjects probably caused by retarded gastric emptying. However, in the pancreatic insufficient subjects, use of a liquid meal resulted in significantly lower plasma p-aminobenzoic acid levels at all time points; plasma p-aminobenzoic acid at 2 and 3 hours completely discriminated between control and pancreatic insufficient patients. Evaluation of the data by area under the time-concentration curve failed to improve test results. In conclusion, the bentiromide test is a simple, clinically useful means of detecting pancreatic insufficiency in young children, but a higher dose administered with a liquid meal is recommended.
Resumo:
Tutkimuksen tarkoituksena on analysoida eräitä lakitermejä, jotka esiintyvät papyruksessa P. Petra inv. 83. Kyseinen dokumentti, joka sisältää sopimuksen kahden naapuruksen välisen kiistan lopettamiseksi, ajoittuu todennäköisesti vuodelle 574 jKr. ja se kuuluu Jordanian Petrasta vuonna 1993 löydettyyn hiiltyneeseen papyrusarkistoon. Papyrus on tällä hetkellä vielä julkaisematon, ja tämä työ on osa siihen liittyvää perustutkimusta, jonka tarkoituksena on toisaalta selittää tekstin itsensä sisältö, toisaalta arvioida sen antaman informaation merkitystä laajemmassa historiallisessa kontekstissa. Papyrus on kirjoitettu kreikaksi, Bysantin eli Itä-Rooman valtakunnan virallisella kielellä, mutta itse lakitermeistä suurin osa liittyy alun perin latinan kielellä luotuun roomalaiseen oikeuteen. Paikallinen väestö puolestaan oli seemiläistä alkuperää, jolla ei ainoastaan ollut oma kieli, vaan jolla oli ollut ennen valtakuntaan liittämistä omat oikeustraditionsakin. Niinpä papyruksessa esiintyvien termien tutkimuksen kautta nousevat esille monenlaiset laajemmatkin kysymyksenasettelut. Lakitermejä analysoidaan pääasiassa kolmesta näkökulmasta. Ensisijaisena pyrkimyksenä on selvittää niiden tarkka merkitys asiayhteydessään, joka papyruksen fragmentaarisuuden vuoksi ei ole etukäteen selvä, ja siten edistää tekstissä puheena olevien asianhaarojen ymmärtämistä. Toiseksi termien käyttöä koskevat tulokset suhteutetaan yleiseen oikeushistoriaan ja pyritään arvioimaan niiden merkitystä Petrassa käytössä olleen oikeusjärjestelmän kannalta. Kolmas näkökulma on kielitieteellinen, sillä termien käyttö papyruksessa on nähtävä osana laajempaa kehitystä, jossa roomalaisen oikeuden vähittäinen muuttuminen bysanttilaiseksi johti kielten vaihtumiseen ja koko juridisen käsitteistön siirtymiseen latinasta kreikkaan. Siksi tässä työssä käytetään itse papyruksen analyysin lisäksi laajaa vertailumateriaalia, joka koostuu ennen kaikkea roomalaisesta ja bysanttilaisesta lakikirjallisuudesta sekä dokumentaarisesta lähdeaineistosta, etenkin egyptiläisistä papyruksista. Niin tässä papyruksessa kuin muissakin kreikankielisissä lähteissä esiintyvät roomalaiseen oikeuteen liittyvät termit voidaan jaotella suoriin lainoihin, käännöslainoihin sekä komparaatiolainoihin. Jälkimmäisillä tarkoitetaan kreikan kielessä jo aiemmin käytössä olleita termejä, jotka eivät sananmukaiselta merkitykseltään vastaa latinalaisia, mutta joita alettiin käyttää jonkin latinalaisen termin vastineina. Tutkimus tekee selväksi, että olipa kyse mistä lainakategoriasta tahansa, lakitermien siirtyessä kielestä toiseen tapahtui yleensä semanttisia muutoksia eikä termejä aina käytetty samalla tavalla kuin alkukielessä. Merkityskenttä saattoi esimerkiksi supistua taikka laajentua tai sanalle saattoi kehittyä lainautumisen jälkeen täysin uusiakin merkityksiä. Oikeushistorian suhteen on huomioitava ero virallisten säännösten ja provinsseissa noudatettujen käytäntöjen välillä. Kaiken kaikkaan Petra näyttää kuitenkin olleen kiinteä osa Bysantin valtakuntaa, jonka lakeja ainakin pääpiirteissään noudatettiin. Kaikkien termien käytötavat eivät tosin ole johdettavissa suoraan virallisiin lakikorpuksiin, mutta ne eivät myöskään sodi niitä vastaan. Roomalaisen oikeuden tuntemus näyttää olleen Petrassa jopa parempaa kuin esimerkiksi Egyptissä. Mitä tulee papyruksessa puheena oleviin konkreettisiin asianhaaroihin, termien merkityksen ymmärtäminen selventää joidenkin aspektien pääpiirteitä, kun taas yksityskohdat jäävät tekstin fragmentaarisuuden takia useimmiten epäselviksi. Avainsanat: papyrologia, Petra, roomalainen oikeus, terminologia, kreikan kieli, latinan kieli, lainasanat
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Measurements of the ratio of diffusion coefficient to mobility (D/ mu ) of electrons in SF6-N2 and CCl2F2-N2 mixtures over the range 80
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Although the fisheries for, and mariculture of, penaeid prawns are of major commercial importance, there has been relatively little research undertaken on the chromosome number, structure and composition in the Penaeidae. One reason for this is due to the relatively small size and large number of chromosomes, which makes production of histological material difficult. In this paper, we report a simple and effective technique for determining chromosome complements during spermatogenesis in two species of penaeid prawns, Penaeus merguiensis and P. esculentus in Australia. The first estimates of the number of chromosomes in these species are given.