Soils and agriculture in central-west and north Brazil

Modern soil science, spearheaded by research in Brazil has facilitated the utilization of vast areas of previously uncultivated soil long considered unsuitable for human food production into highly productive agricultural land. Naturally acid soils with high contents of aluminum and iron oxides and low CEC values and organic matter contents long considered insurmountable obstacles to crop production in tropical latitudes could be extremely productive. With continued development of the infrastructure needed by commercial agriculture Brazil has the potential to lead the world in its quest to provide food for growing human populations.A moderna ciência de solo, liderada pelas suas pesquisas no Brasil, tem possibilitado a utilização de vastas áreas de solos, durante muito tempo não cultivados por serem avaliados como inaptos para uma intensiva produção de alimentos. Hoje, ao contrário, constata-se que essas terras são altamente produtivas para a agricultura. Estas pesquisas vêm mostrando que alguns atributos naturais destes solos, como acidez, baixos teores de matéria orgânica, baixa capacidade de troca de cátions, além de altos teores de óxidos de ferro e/ou de alumínio - considerados como obstáculos à produção de boas colheitas em latitudes tropicais - podem ser superados. Com a continuação do desenvolvimento das infra-estruturas necessárias para alavancar ainda mais a agricultura comercial, o Brasil tem potencial para, em breve, liderar o mundo no que tange ao fornecimento de alimentos para as crescentes populações humanas

Time-Varying and Static Magnetic Fields Act in Combination to Alter Calcium Signal Transduction in the Lymphocyte

AbstractWe have tested the hypothesis that extremely low frequency (ELF) time-varying magnetic fields act in combination with static magnetic fields to alter calcium signalling in the lymphocyte. Results indicate that a 60-min exposure of thymic lymphocytes at 37 ± 0.05°C to a 16 Hz, 421 mG (42.1 μT) magnetic field simultaneously with a colinear static magnetic field of 234 mG (23.4 μT) (a.c./d.c. field intensity ratio = 1.8) inhibits calcium influx triggered by the mitogen Concanavalin A. Significantly, resting lymphocytes do not respond to the fields, thus, only mitogen-activated cells undergoing calcium signalling exhibit a field response. These results indicate that signal transduction involving calcium is an important biological constraint which operates to mediate this field interaction. Additional split field exposures show that the presence of the a.c. field or the d.c. field alone does not produce an effect. This is consistent with a proposed parametric resonance theory of interaction of low intensity magnetic fields with biological systems (L.L. Lednev (1991) Bioelectromagnetics 12, 71–75), which predicts the occurrance or biological effects at specific values for the frequency and field intensity of the ELF and static magnetic fields

Sexual subjectification and <i>Bitchy Jones's Diary</i>

This paper presents the reflections of two academics on the blog Bitchy Jones's Diary (2006-2010), particularly its considerations of dominant femininity within the UK kink communities. Weaving together excerpts from the blog with our own dialogues, we consider the potentials of such a voice from within the communities in relation to more academic explorations. Specifically we focus on the relationship between Bitchy Jones's arguments and our own understandings of limited sexualised femininities available within wider culture, the place of agency within these, and the potentials for mutual recognition within both kinky, and non-kinky, relationships