Holocene environmental changes in the lower Thames Valley, London, UK: implications for our understanding of the history of Taxus woodland

A radiocarbon-dated multiproxy palaeoenvironmental record from the Lower Thames Valley at Hornchurch Marshes has provided a reconstruction of the timing and nature of vegetation succession against a background of Holocene climate change, relative sea level movement and human activities. The investigation recorded widespread peat formation between c. 6300 and 3900 cal. yr BP (marine ‘regression’), succeeded by evidence for marine incursion. The multiproxy analyses of these sediments, comprising pollen, Coleoptera, diatoms, and plant and wood macrofossils, have indicated significant changes in both the wetland and dryland environment, including the establishment of Alnus (Alder) carr woodland, and the decline of both Ulmus (Elm; c. 5740 cal. yr BP) and Tilia (Lime; c. 5600 cal. yr BP, and 4160–3710 cal. yr BP). The beetle faunas from the peat also suggest a thermal climate similar to that of the present day. At c. 4900 cal. yr BP, Taxus (L.; Yew) woodland colonised the peatland forming a plant community that has no known modern analogue in the UK. The precise reason, or reasons, for this event remain unclear, although changes in peatland hydrology seem most likely. The growth of Taxus on peatland not only has considerable importance for our knowledge of the vegetation history of southeast England, and NW Europe generally, but also has wider implications for the interpretation of Holocene palaeobotanical records. At c. 3900 cal. yr BP, Taxus declined on the peatland surface during a period of major hydrological change (marine incursion), an event also strongly associated with the decline of dryland woodland taxa, including Tilia and Quercus, and the appearance of anthropogenic indicators.

Application of complex extreme learning machine to multiclass classification problems with high dimensionality: a THz spectra classification problem

We extend extreme learning machine (ELM) classifiers to complex Reproducing Kernel Hilbert Spaces (RKHS) where the input/output variables as well as the optimization variables are complex-valued. A new family of classifiers, called complex-valued ELM (CELM) suitable for complex-valued multiple-input–multiple-output processing is introduced. In the proposed method, the associated Lagrangian is computed using induced RKHS kernels, adopting a Wirtinger calculus approach formulated as a constrained optimization problem similarly to the conventional ELM classifier formulation. When training the CELM, the Karush–Khun–Tuker (KKT) theorem is used to solve the dual optimization problem that consists of satisfying simultaneously smallest training error as well as smallest norm of output weights criteria. The proposed formulation also addresses aspects of quaternary classification within a Clifford algebra context. For 2D complex-valued inputs, user-defined complex-coupled hyper-planes divide the classifier input space into four partitions. For 3D complex-valued inputs, the formulation generates three pairs of complex-coupled hyper-planes through orthogonal projections. The six hyper-planes then divide the 3D space into eight partitions. It is shown that the CELM problem formulation is equivalent to solving six real-valued ELM tasks, which are induced by projecting the chosen complex kernel across the different user-defined coordinate planes. A classification example of powdered samples on the basis of their terahertz spectral signatures is used to demonstrate the advantages of the CELM classifiers compared to their SVM counterparts. The proposed classifiers retain the advantages of their ELM counterparts, in that they can perform multiclass classification with lower computational complexity than SVM classifiers. Furthermore, because of their ability to perform classification tasks fast, the proposed formulations are of interest to real-time applications.

Rotas de persuasão na propaganda impressa de produtos e serviços no Brasil: um estudo comparativo

O objetivo principal do trabalho é entender melhor como ocorre a persuasão dos consumidores de produtos e de serviços. Nesse intuito. foi desenvolvido um estudo comparativo entre anúncios impressos de equipamentos de informática e de serviços de bancos, para constatar se, nessas categorias de produtos e de serviços , são utilizadas formas de argumentação diferentes com base nas rotas de persuasão do consumidor. Para investigar a formação de atitudes dos consumidores relativas a produtos versus serviços , este trabalho utilizou o modelo de probabilidade de elaboração - Elaboration Likelihood Model (ELM) - proposto por Petty e Cacioppo, e a teoria do envolvimento. A metodologia utilizada foi a análise de conteúdo. A coleta de dados concentrou-se nos textos e imagens dos anúncios de equipamentos de informática e de serviços de bancos publicados na Revista Exame em 2001 . Os dados foram coletados, examinados e classificados de acordo com as formas de argumentação central ou periférica, por meio de quatro variáveis: visual central, visual periférica, textual central e textual periférica. Os resultados obtidos sinalizaram para a existência de diferentes formas de argumentação nos anúncios dos produtos tangíveis e produtos intangíveis da amostra pesquisada. Nos anúncios de equipamentos de informática predominou a argumentação central e nos anúncios de serviços de bancos, a argumentação periférica.

Respostas do milho à adubação com fósforo e zinco

With the objective of evaluating the effects of phosphorus (0, 50, 100, 150 and 200 kg ha(-1) of P(2)O(5)) and zinc (0, 5, 10, 15 and 20 kg ha(-1) of Zn) fertilization in the maize crop, a field experiment was conducted on a Haplustox soil with 5 mg dm(3) of P and 0.39 mg dm(-3) of Zn (DTPA). From the results, it was observed that the fertilization with P and Zn resulted in significant increments of corn grain yield. The effect of P fertilization was higher than the fertilization with Zn. It was possible to obtain a production of grain up to 6,000 kg ha(-1) with P alone; higher yield than it was achieved only with both P and Zn fertilization. The maximum corn grain yield was associated with P contents in soil about 30 mg dm(-3). Phosphorus did not alter the contents of Zn in the leaves.

Development of a scar marker for Pierce's Disease strains of Xylella fastidiosa

O objetivo deste trabalho foi desenvolver um oligonucleotídeo iniciador para reação em cadeia da polimerase (PCR) específico para as estirpes de Xylella fastidiosa que causam o mal de Pierce (PD) em videira (Vitis vinifera). Amplificações de DNA de 23 diferentes hospedeiros, usando o conjunto de oligonucleotídeos REP1-R (5'-IIIICGICGIATCCIGGC-3') e REP 2 (5'-ICGICTTATCI GGCCTAC-3') utilizando o programa: 94 ºC/2 min; 35 X (94 ºC/1 min, 45 ºC/1 min; 72 ºC/1 min and 30 s) 72 ºC/5 min, produziu um fragmento de 630 pb que diferenciou as estirpes de videiras dos demais. Entretanto, padrões de bandeamento REP não são considerados confiáveis para detecção devido ao par de oligonucleotídeos REP 1 e REP 2 corresponderem a seqüências repetitivas encontradas por todo o genoma bacteriano. Desse modo, o produto amplificado de 630 pb foi eluído do gel de agarose, purificado e seqüenciado. A informação da seqüência nucleotídica foi usada para identificar e sintetizar um oligonucleotídeo específico para o isolado de X. fastidiosa causadora do mal de Pierce denominado Xf-1 (5'-CGGGGGTGTAGGAGGGGTTGT-3'), que foi utilizado juntamente com o oligonucleotídeo REP-2 nas condições 94 ºC/2 min; 35 X (94 ºC/1 min, 62 ºC/1 min; 72 ºC/1 min and 30 s) 72 ºC/10 min. Os DNAs das estirpes de X. fastidiosa de outros hospedeiros [amêndoa (Prumus amygdalus), citros (Citrus spp.), café (Coffea arabica), olmo (Ulmus americana), amora (Morus rubra), carvalho (Quercus rubra), vinca (Catharantus roseus), ameixa (Prunus salicina) e ragweed (Ambrosia artemisiifolia)] e de bactérias Gram negativas e positivas foram submetidos a amplificação com o conjunto de oligonucleotídeos Xf-1/REP 2. Um fragmento, de aproximadamente 350 pb, foi amplificado apenas com o DNA de X. fastidiosa isolada de videira.

An evaluation of the genetic diversity of Xylella fastidiosa isolated from diseased citrus and coffee in São Paulo, Brazil

Strains of Xylella fastidiosa, isolated from sweet orange trees (Citrus sinensis) and coffee trees (Coffea arabica) with symptoms of citrus variegated chlorosis and Requeima do Cafe, respectively, were indistinguish able based on repetitive extragenic palindromic polymerase chain reaction (PCR) and enterobacterial repetitive intergenic consensus PCR assays. These strains were also indistinguishable with a previously described PCR assay that distinguished the citrus strains from all other strains of Xylella fastidiosa. Because we were not able to document any genomic diversity in our collection of Xylella fastidiosa strains isolated from diseased citrus, the observed gradient of increasing disease severity from southern to northern regions of São Paulo State is unlikely due to the presence of significantly different strains of the pathogen in the different regions. When comparisons were made to reference strains of Xylella fastidiosa isolated from other hosts using these methods, four groups were consistently identified consistent with the hosts and regions from which the strains originated: citrus and coffee, grapevine and almond, mulberry, and elm, plum, and oak. Independent results from random amplified polymorphic DNA (RAPD) PCR assays were also consistent with these results; however, two of the primers tested in RAPD-PCR were able to distinguish the coffee and citrus strains. Sequence comparisons of a PCR product amplified from all strains of Xylella fastidiosa confirmed the presence of a CfoI polymorphism that can be used to distinguish the citrus strains from all others. The ability to distinguish Xylella fastidiosa strains from citrus and coffee with a PCR-based assay will be useful in epidemiological and etiological studies of this pathogen.

Effect of potassium fertilization in 'Rica' guava (Psidium guajava) cultivation

A field experiment was conducted from 1989-90 to 1991-92 to study the effect of potassium fertilization on guava (Psidium guajava L.). using 1-year-old plants of 'Rica', grown in a Kanhapludalf soil in the Jaboticabal region in Brazil. During the first year the K doses used were: 0, 24.9, 49.8, 99.6, 149.4 and 199.2 g K/plant, which were doubled during the second year and tripled during the third. In the third year the increase in g level showed positive response in yield. About 90% of the maximum yield observed was associated with 527 g K/plant and with a leaf content of 18.9 g K/kg.

Does the male reproductive performance depend on the early lactation milk in rats?

This study investigated the role of the early lactation milk (ELM) on the male reproductive performance and the participation of GnRH on this effect in Wistar rats. Newborn males were divided into three experimental groups: 1) ELM-deprived pups, 2) ELM-deprived pups treated with exogenous GnRH 1, 7, 25, and 31 h after birth, and 3) non-ELM-deprived and without exogenous GnRH. In relation to the other two groups, the ELM-deprived male rats exhibited as adults: reduced fertility, decreased weight of both vas deferens and seminal vesicle, and reduced levels of fructose in the seminal vesicle and prostate gland. We suggest that the intake of ELM during the neonatal period is important to the later sexual development of rats, and that GnRH is somehow involved in such an effect.

Análise filogenética de linhagens de Xylella fastidiosa de diferentes hospedeiros baseada na sequencia da região intergênica 16S-23S rDNA

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Composição corporal e exigências nutricionais de caprinos Saanen machos dos 30 aos 45 kg de peso vivo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of Xylella fastidiosa genetic diversity by fAFPL markers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Identification and genetic diversity in phytoplasmas associated with diseases of cassava and other agronomic relevant crops in south-east Asia and Latin America

Identification and genetic diversity of phytoplasmas infecting tropical plant species, selected among those most agronomically relevant in South-east Asia and Latin America were studied. Correlation between evolutionary divergence of relevant phytoplasma strains and their geographic distribution by comparison on homologous genes of phytoplasma strains detected in the same or related plant species in other geographical areas worldwide was achieved. Molecular diversity was studied on genes coding ribosomal proteins, groEL, tuf and amp besides phytoplasma 16S rRNA. Selected samples infected by phytoplasmas belonging to diverse ribosomal groups were also studied by in silico RFLP followed by phylogenetic analyses. Moreover a partial genome annotation of a ‘Ca. P. brasiliense’ strain was done towards future application for epidemiological studies. Phytoplasma presence in cassava showing frog skin (CFSD) and witches’ broom (CWB) diseases in Costa Rica - Paraguay and in Vietnam – Thailand, respectively, was evaluated. In both cases, the diseases were associated with phytoplasmas related to aster yellows, apple proliferation and “stolbur” groups, while only phytoplasma related to X-disease group in CFSD, and to hibiscus witches’ broom, elm yellows and clover proliferation groups in CWB. Variability was found among strains belonging to the same ribosomal group but having different geographic origin and associated with different disease. Additionally, a dodder transmission assay to elucidate the role of phytoplasmas in CWB disease was carried out, and resulted in typical phytoplasma symptoms in periwinkle plants associated with the presence of aster yellows-related strains. Lethal wilt disease, a severe disease of oil palm in Colombia that is spreading throughout South America was also studied. Phytoplasmas were detected in symptomatic oil palm and identified as ‘Ca. P. asteris’, ribosomal subgroup 16SrI-B, and were distinguished from other aster yellows phytoplasmas used as reference strains; in particular, from an aster yellows strain infecting corn in the same country.