Equiangular lines in Euclidean spaces

We obtain several new results contributing to the theory of real equiangular line systems. Among other things, we present a new general lower bound on the maximum number of equiangular lines in d dimensional Euclidean space; we describe the two-graphs on 12 vertices; and we investigate Seidel matrices with exactly three distinct eigenvalues. As a result, we improve on two long-standing upper bounds regarding the maximum number of equiangular lines in dimensions d=14, and d=16. Additionally, we prove the nonexistence of certain regular graphs with four eigenvalues, and correct some tables from the literature.Comment: 24 pages, to appear in JCTA. Corrected an entry in Table

Caracterização de cluster gênico biossintético para produção de peptídeos em Trichoderma MMSRG12.

No presente estudo, objetivou-se identificar e caracterizar o cluster gênico biossintético para produção de peptaibols com base no genoma completo de Trichoderma sp. MMSRG12

Produção de peptídeos da classe dos peptaibols por Trichoderma amazonicum.

Tendo em vista o potencial biotecnológico desse organismo e a diversidade de espécies com importância química, este estudo visou a caracterização química de peptaibols produzidos por um fungo Amazônico

Seasonal effects on HPLC-DAD-UV and UPLC-ESI-MS fingerprints and analgesic activities of vernonia condensata baker extracts

Vernonia condensata Baker leaves have different uses in Brazilian folk medicine, including as analgesic and anti-inflammatory agents. The purpose of this study was to evaluate the seasonal effects on their high performance liquid chromatography with a diode array detector (HPLC-DAD-UV) and ultra-performance liquid chromatography coupled to a mass spectrometer with an electrospray interface (UPLC-ESI-MS) fingerprints, as well as their analgesic activities in mice. There were significant seasonal effects on the relative abundances of the metabolites of the V. condensate leaves as well as on their activities. Analgesic activities in the writhing test were observed with the polar fraction of the leaf extracts collected in autumn, winter and summer (400 mg kg(-1)); and with the intermediate fraction of leaves collected in autumn (25 and 400 mg kg(-1)) and in the summer (100 mg kg(-1)). In conclusion, the results confirm peripherally-mediated anti-inflammatory and analgesic activities for V. condensata leaves and suggest that these are influenced by the harvesting season. N-oxides alkaloids as well as vernonioside play important roles in determining this activity262350358CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFundacao Araucari

The Erd\H{o}s-Ko-Rado theorem for twisted Grassmann graphs

We present a "modern" approach to the Erd\H{o}s-Ko-Rado theorem for Q-polynomial distance-regular graphs and apply it to the twisted Grassmann graphs discovered in 2005 by van Dam and Koolen.Comment: 5 page

Beyond the Book: Linking Books to Wikipedia

The book translation market is a topic of interest in literary studies, but the reasons why a book is selected for translation are not well understood. The "Beyond the Book" project investigates whether web resources like Wikipedia can be used to establish the level of cultural bias. This work describes the eScience tools used to estimate the cultural appeal of a book: semantic linking is used to identify key words in the text of the book, and afterwards the revision information from corresponding Wikipedia articles is examined to identify countries that generated a more than average amount of contributions to those articles. Comparison between the number of contributions from two countries on the same set of articles may show with which knowledge the contributors are familiar. We assume a lack of contributions from a country may indicate a gap in the knowledge of readers from that country. We assume that a book dealing with that concept could be more exotic and therefore more appealing for certain readers, while others are therefore less interested in the book. An indication of the 'level of exoticness' thus could help a reader/publisher to decide to read/translate the book or not. Experimental results are presented for four selected books from a set of 564 books written in Dutch or translated into Dutch, assessing their potential appeal for a Canadian audience. A qualitative assessment of quantitative results provides insight into named entities that may indicate a high/low cultural bias towards a book

Leishmanicidal activity of fractions rich in aporphine alkaloids from amazonian unonopsis species

In vitro evaluation of alkaloidal fractions of twigs, barks and leaves from two Unonopsis species, Unonopsis guatterioides R.E. Fr. and Unonopsis duckei R.E. Fr., Annonaceae, against promastigote forms of Leishmania amazonensis revealed these species as sources of substances with promising leishmanicidal potential. All alkaloidal fractions from twigs, barks and leaves of U. guatterioides were classified as highly active, with IC50 1.07, 1.90, and 2.79 mg/mL, respectively. Only the alkaloidal fraction from the twigs of U. duckei was classified as inactive2261368137

Leishmanicidal activity of fractions rich in aporphine alkaloids from Amazonian Unonopsis species

In vitro evaluation of alkaloidal fractions of twigs, barks and leaves from two Unonopsis species, Unonopsis guatterioides R.E. Fr. and Unonopsis duckei R.E. Fr., Annonaceae, against promastigote forms of Leishmania amazonensis revealed these species as sources of substances with promising leishmanicidal potential. All alkaloidal fractions from twigs, barks and leaves of U. guatterioides were classified as highly active, with IC50 1.07, 1.90, and 2.79 mg/mL, respectively. Only the alkaloidal fraction from the twigs of U. duckei was classified as inactive.2261368137