Polyamines, IAA and ABA during germination in two recalcitrant seeds: Araucaria angustifolia (Gymnosperm) and Ocotea odorifera (Angiosperm)

Background and Aims Plant growth regulators play an important role in seed germination. However, much of the current knowledge about their function during seed germination was obtained using orthodox seeds as model systems, and there is a paucity of information about the role of plant growth regulators during germination of recalcitrant seeds. In the present work, two endangered woody species with recalcitrant seeds, Araucaria angustifolia (Gymnosperm) and Ocotea odorifera (Angiosperm), native to the Atlantic Rain Forest, Brazil, were used to study the mobilization of polyamines (PAs), indole-acetic acid (IAA) and abscisic acid (ABA) during seed germination. Methods Data were sampled from embryos of O. odorifera and embryos and megagametophytes of A. angustifolia throughout the germination process. Biochemical analyses were carried out in HPLC. Key Results During seed germination, an increase in the (Spd + Spm) : Put ratio was recorded in embryos in both species. An increase in IAA and PA levels was also observed during seed germination in both embryos, while ABA levels showed a decrease in O. odorifera and an increase in A. angustifolia embryos throughout the period studied. Conclusions The (Spd + Spm) : Put ratio could be used as a marker for germination completion. The increase in IAA levels, prior to germination, could be associated with variations in PA content. The ABA mobilization observed in the embryos could represent a greater resistance to this hormone in recalcitrant seeds, in comparison to orthodox seeds, opening a new perspective for studies on the effects of this regulator in recalcitrant seeds. The gymnosperm seed, though without a connective tissue between megagametophyte and embryo, seems to be able to maintain communication between the tissues, based on the likely transport of plant growth regulators.

The importance of dietary calcium consumption in two species of semi-terrestrial grapsoid crabs

Calcium (Ca) is essential for crustaceans, due to calcium carbonate (CaCO(3)) deposition in the new exoskeleton to harden it. The purpose of this work was to study short term Ca balance in terms of dietary Ca ingestion in two phylogenetically related crabs (Superfamily Grapsoidea) showing different degrees of terrestrial adaptations: Sesarma rectum Randall, 1840 and Neohelice granulata (Dana, 1851). Dietary Ca ingestion was studied using purified diets with different Ca concentrations (0, 2.2 and 6.66% Ca), together with measurements of Ca excretion and Ca hemolymph levels. The results showed that both crabs had the same response to foods containing different levels of Ca, with both species eating more of the high Ca diet. However, S. rectum consumed more per mg body mass at all Ca concentrations (6 mg.g(-1) for S. rectum against 3 mg.g(-1) for N. granulata). Both species excreted/egested Ca differently: S. rectum excreted Ca proportionally to ingestion, whereas N. granulata maintained constant faecal Ca output at all dietary Ca levels. Moreover, Ca hemolymph levels for crabs fed the different diets were independent of dietary Ca. In conclusion, both S. rectum and N. granulata seem to regulate the consumption of diets containing more Ca, which suggests a fine balance for Ca intake.

Blurred femtoscopy in two-proton decay

We study the effects of final state interactions in two-proton emission by nuclei. Our approach is based on the solution the time-dependent Schrodinger equation. We show that the final relative energy between the protons is substantially influenced by the final state interactions. We also show that alternative correlation functions can be constructed showing large sensitivity to the spin of the diproton system. (c) 2008 Elsevier B.V. All rights reserved.

On the lower bound on the exchange-correlation energy in two dimensions

We study the properties of the lower bound on the exchange-correlation energy in two dimensions. First we review the derivation of the bound and show how it can be written in a simple density-functional form. This form allows an explicit determination of the prefactor of the bound and testing its tightness. Next we focus on finite two-dimensional systems and examine how their distance from the bound depends on the system geometry. The results for the high-density limit suggest that a finite system that comes as close as possible to the ultimate bound on the exchange-correlation energy has circular geometry and a weak confining potential with a negative curvature. (c) 2009 Elsevier B.V. All rights reserved.

A modified signed likelihood ratio test in elliptical structural models

In this paper we deal with the issue of performing accurate testing inference on a scalar parameter of interest in structural errors-in-variables models. The error terms are allowed to follow a multivariate distribution in the class of the elliptical distributions, which has the multivariate normal distribution as special case. We derive a modified signed likelihood ratio statistic that follows a standard normal distribution with a high degree of accuracy. Our Monte Carlo results show that the modified test is much less size distorted than its unmodified counterpart. An application is presented.

From the Reliable and Unselfish to the Versatile and Independent : - desired qualities in two Swedish curricula

The process in which girls and boys are constructed and construct themselves to pupils takes place in a context where conceptions of “the good pupil” are distinctly manifested in national school documents. In different types of texts concerning school and education, the image of the pupil that society wants to create emerges. Documents from early childhood education up to university level prioritise qualities such as independence, initiative, accountability and freedom to make ones own choices. Qualities or competencies that are preferred during a certain period change as time passes and society develops. The idea of the democratic subject is not the same today as it was 25 years ago. The purpose of this article is to emphasise and compare different desired qualities described in two Swedish national curricula, competencies that pupils in the compulsory school are supposed to develop. The discussion encompasses the political ideas of the pupil during a period of twenty-five years in light of changes in Western societies during the last decades.

English-medium instruction in Sweden : Perspectives and practices in two upper secondary schools

This thesis presents English-medium instruction (EMI) in the Swedish context, focusing on perspectives and practices in two schools. The research question is as follows: How and why is EMI offered, chosen, and practiced in the Swedish upper secondary school today? The aim is to explore the status of the educational option, the reasons for offering EMI to stakeholders, the stakeholders’ beliefs about and goals of EMI, and the implementation of EMI in the classroom. A survey of all upper secondary schools in Sweden was conducted to ascertain the spread of content teaching through a foreign language. The educational context was studied from an ecological perspective using methods based in linguistic ethnography. Language alternation, academic language, and language hierarchy were all considered. Interviews were analysed for content; and classroom language use was analysed for language choice and function. The concepts of affordance and scaffolding together with translanguaging were key. The de facto policies of the micro contexts of the schools were examined in light of the declared national policy of the macro context of Sweden. The results indicate that the option in Swedish schools has not increased, and also tends to only be EMI—not Content and Language Integrated Learning (CLIL) or instruction through other languages. EMI is offered for prestige, an international profile, marketing potential and personal interest. EMI students are academically motivated and confident, and see the option as “fun”. 100% EMI in the lessons is not the goal or the practice. Translanguaging is abundant, but how language alternation is perceived as an affordance or not differs in the two schools. One focuses on how the languages are used while the other focuses on how much each language is used. In conclusion, the analysis suggests that a development of definitions and practices of EMI in Sweden is needed, especially in relation to language policy and language hierarchy.

Mineralogy of the clay fraction of Alfisols in two slope curvatures: III - spatial variability

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

Mineralogy of the clay fraction of alfisols in two slope curvatures: IV - spatial correlation with physical properties

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

Population Fluctuations of Formicidae (Hymenoptera) and Araneae (Arachnida) in Two Tillage Systems in the Region of Guaíra-SP

The objective of this study was to elucidate population fluctuations of spider and ant species in forest fragments and adjacent soybean and corn crops under no-tillage and conventional tillage systems, and their correlations with meteorological factors. From Nov 2004 to Apr 2007 sampling of these arthropods at Guaira, São Paulo state was done biweekly during the cropping season and monthly during the periods between crops. To obtain samples at each experimental site, pitfall traps were distributed in 2 transects of 200 m of which 100 m was in the crop, and 100 m was in the forest fragment. Temperature and rainfall were found to have major impacts on fluctuations in population densities of ants of the genus, Pheidole, in soybean and corn crops both grown with conventional tillage and no tillage systems.

Diversity and habitat preferences of Carabidae and Staphylinidae (Coleoptera) in two agroecosystems

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

Hematological parameters in two neotropical freshwater teleost, Leporinus macrocephalus (Anostomidae) and Prochilodus lineatus (Prochilodontidae)

Leporinus macrocephalus is a non-migratory omnivore fish which occurs in waters with a relatively high oxygen rate. Prochilodus lineatus is a migratory fish that inhabits deoxygenated hypolimnion and feeds on detritus material. Red blood cell, thrombocytes and white blood cell counts, hematocrit and hemoglobin, serum electrolytes (sodium, potassium, calcium, magnesium and chloride), metabolic products (total serum protein and plasma glucose) and blood cells major axis length for L. macrocephalus and P. lineatus were compared. White blood cell counts for both species indicated a similar activity of the immune functions. The concentration of total protein, sodium, calcium, magnesium and chloride, MCV, as well as red blood cells, monocytes, and thrombocytes size in L. macrocephalus were higher than in P. lineatus. However, P. lineatus had higher red blood cell counts, hematocrit and hemoglobin, which reflects a considerable adaptation to survive in an environment with low levels of oxygen.

Carbon, nitrogen and phosphorus mineralization in two soils amended with distillery yeast

The possibility of using yeast from alcohol distilleries as a source of nutrients in soil was investigated. The following treatments were used: no fertilization (control), 0.5% (w/w) yeast, 1% (w/w) yeast, and NPK. The decomposition of yeast was monitored for 90 days in two soils. The CO, production and the microbial biomass were increased by art average of 1- to 3-fold by yeast incorporation compared to control. Protease activity also was enhanced 3- to 8-fold in the soils supplemented with yeast compared to control. The phosphatase activities were higher than control only during the first days. While nitrate contents increased in all treatments compared to control, available P only increased in the soils amended with 1%, yeast or NPK by 45-119% and 309-489%, respectively. These results indicate that there exists an excellent potential for the use of yeast in the soil as a source of nitrate and available P for plant nutrition. (C) 2003 Elsevier Ltd. All rights reserved.