Nitrate retention under sugarcane in wet tropical Queensland deep soil profiles

Nitrate leaching below the crop root-zone in variable charge soils may be adsorbed at anion exchange sites, thereby temporarily reducing the risk of contamination of water bodies. The objectives of this study were (i) to investigate whether nitrate adsorption, accumulation, and retention in the Johnstone River Catchment of Far North Queensland wet tropics is widespread; (ii) to assess the capacity of soil in the Johnstone River Catchment to retain nitrate; and (iii) to deduce the consequences of nitrate adsorption/desorption on contamination of water bodies. Soil cores ranging from 8 to 12.5 m depth were taken from 28 sites across the catchment, representing 9 Ferrosol soil types under sugarcane (Saccharum officinarum-S) cultivation for at least 50 years and from rainforest. The cores were segmented at 0.5-m depth increments and subsamples were analysed for nitrate-N, cation and anion exchange capacities, pH, exchangeable cations (Ca, Mg, K, Na), soil organic C, electrical conductivity, sulfate-S, and chloride. Nitrate-N concentration under sugarcane ranged from 0 to 72.5 mg/kg, compared with 0 to 0.31 mg/kg under rainforest, both Pin Gin soils. The average N load in 1-12 m depth across 19 highly oxidic profiles of the Pin Gin soil series was 1550 kg/ha, compared with 185 kg/ha under 8 non-Pin Gin soils and 11 kg/ha in rainforest on a Pin Gin soil. Most of the nitrate retention was observed at depth of 2-12 m, particularly at 4-10 m, indicating that the accumulation was well below the crop root-zone. The average maximum potential nitrate retention capacity was 10.8 t/ha for the Pin Gin and 4.7 t/ha for the non-Pin Gin soil. Compared with the current N load, the soils still possess a large capacity to adsorb and retain nitrate in profiles. Retention of large quantities of the leached nitrate deep in most of the profiles has reduced the risk of contamination of water bodies. However, computations show that substantial quantities of the nitrate leached below the root-zone were not adsorbed and remain unaccounted for. This unaccounted nitrate might have entered both on- and off-site water bodies and/or have been denitrified.

The Utility of the Human Security Agenda for Policy-makers

The idea of “human security” is gaining attention among policy-makers and security analysts. Little scholarly attention has been given to the questions of why states accept (or reject) a human security agenda or how such an agenda is incorporated into policy practices. The article suggests that a human security approach is most likely to be applied when both humanitarian and national interests combine. Yet when states or organisations adopt a human security approach, they often misjudge the complex and long-term commitment required of such an approach. There is also the potential for such an agenda to be manipulated to justify questionable courses of action. These issues frame an analysis of six recent case studies.

A????es premiadas no 8?? Concurso Inova????o na Gest??o P??blica Federal

Projetos premiados no 8?? Concurso Inova????o na Gest??o P??blica Federal. Representam contribui????es para a melhoria da gest??o p??blica nas seguintes ??reas: articula????o de parcerias, estabelecimento de padr??es de atendimento e servi??os, gerenciamento de informa????es, implementa????o de melhoria cont??nua, inclus??o social e simplifica????o e agiliza????o de procedimentos

Conselho Nacional de Juventude: rede de pol??ticas p??blicas?

O presente trabalho representa uma tentativa de avaliar se o Conselho Nacional de Juventude da Secretaria Geral da Presid??ncia da Rep??blica pode ser entendido como uma rede de pol??ticas p??blicas, conforme a vis??o de Bonafont (2004). Para realizar essa avalia????o optou-se, inicialmente, pela abordagem da an??lise de redes de pol??ticas p??blicas qualitativa e por alguns itens avaliativos. Assim, foram realizadas entrevistas, al??m de pesquisas documentais em livros, boletins informativos, documentos oficiais, s??tios eletr??nicos e outras fontes de informa????es que auxiliaram a montar o hist??rico do Conselho, mapear as suas caracter??sticas, a estrutura, a forma de atua????o e a rela????o entre seus atores. O estudo mostra que, apesar do aumento de capital social trazido pela cria????o de um espa??o p??blico de discuss??o de pol??ticas p??blicas de juventude, o Conselho ainda n??o pode ser considerado uma rede de pol??ticas p??blicas. Identificou-se, principalmente, falta de consenso sobre o tema, aus??ncia de elabora????o de diretrizes sobre as pol??ticas p??blicas de juventude, bem como a inexist??ncia de um conceito ??nico de juventude compartilhado entre seus integrantes. Entretanto, vislumbram-se possibilidades concretas de surgimento de tal estrutura caso alguns requisitos, discutidos no artigo, estejam presentes em futuras realiza????es desse ??rg??o.

Implementa????o de uma pol??tica ambiental no ??mbito do Plano de Desenvolvimento Sustent??vel do Rio Grande do Norte

Num contexto marcado pela difus??o e consolida????o do conceito de desenvolvimento sustent??vel e como desdobramento do Projeto ??ridas ??? estrat??gia de desenvolvimento sustent??vel para o Nordeste brasileiro ???, ?? promulgado, em 1997, o Plano de Desenvolvimento Sustent??vel do Rio Grande do Norte ??? P.D.S./R.N. Constatado o insatisfat??rio grau de cumprimento de suas a????es, este trabalho busca identificar e analisar os fatores que dificultam a implementa????o do P.D.S./R.N., fazendo recorte de uma de suas pol??ticas ??? a pol??tica ambiental. O pressuposto assumido pelo presente trabalho ?? o de que a dificuldade de implementa????o da pol??tica ambiental, contida no P.D.S./R.N., deve-se, de um lado, ?? inefici??ncia do Estado e, de outro, ?? baixa capacidade de articula????o dos atores sociais. Em contraposi????o aos fatores identificados como dificultadores do processo de implementa????o da pol??tica ambiental, s??o sugeridos aspectos pass??veis de aumentar as possibilidades de sucesso de uma pol??tica dessa natureza.

DEVELOPMENT OF A MECHATRONIC SYSTEM FOR BEDRIDDEN PEOPLE SUPPORT

This work is developed in the context of Ambient Assisted Living (AAL) and has, as main purpose, the development of a mechatronic system that allows caring of bedridden patients with ongoing medical care terminal (MCT), by a single person. This system allows higher autonomy in domiciliary care, safety, comfort and hygiene of bedridden patients. It contributes to a large increase in their quality of life as well as the ease of monitoring by providers of continuous care, which, in many cases, may be the family itself. The product includes an embedded processing interface for acquiring physiological data to support online monitoring. The development of this project was focused on improving the quality of life, autonomy, participation in social life and reducing healthcare costs in the area AAL. The developed societies currently face severe demographic changes: the world is aging at an unprecedented rate. In 2000, about 420 million people, or about 7 percent of the world population were over 65 years old. In 2050, that number will be near 1500 million people, about 16 percent of the world population. This demographic trend will be accompanied by the increase of people with physical limitations. This will impose new challenges for traditional health systems, not only for Portugal but also for all European countries. There is an urgent need to find solutions to improve the lives of people in their preferred environment by increasing their autonomy, self-confidence and mobility. Therefore, in the case of household scenarios, the provision of effective health services is of fundamental importance to the welfare and economic development of each country. This ongoing project aims to develop a mechatronic system to meet the diverse needs, namely: improving life, health care, safety, comfort, and remote monitoring of bedridden person.

Social exclusion: practice and fear of exile (degredo) in Portuguese history

Vejo a sociedade portuguesa como sendo naturalmente inclusiva. Quero dizer que esta parece ser uma tendência mais forte do que, por exemplo, no meu país, nos Estados Unidos da América. Isto poderá explicar porque o degredo era eficaz e era muito temido. Dá para entender também os longos períodos de degredo em substituição de pena capital em Portugal. Segundo as estimativas do autor, pelo menos 50,000 portugueses foram deslocados para dentro e fora de Portugal continental entre 1550-1755. O número era muito significativo na segunda metade do século XVIII. O número dos degredados foi ainda maior no século XIX.

Basis invariant conditions for supersymmetry in the two-Higgs-doublet model

The minimal supersymmetric standard model involves a rather restrictive Higgs potential with two Higgs fields. Recently, the full set of classes of symmetries allowed in the most general two-Higgs-doublet model was identified; these classes do not include the supersymmetric limit as a particular class. Thus, a physically meaningful definition of the supersymmetric limit must involve the interaction of the Higgs sector with other sectors of the theory. Here we show how one can construct basis invariant probes of supersymmetry involving both the Higgs sector and the gaugino-Higgsino-Higgs interactions.

Constraints on leptogenesis from a symmetry viewpoint

It is shown that type I seesaw models based on the standard model Lagrangian extended with three heavy Majorana right-handed fields do not have leptogenesis in leading order, if the symmetries of mass matrices are also the residual symmetry of the Lagrangian. In particular, flavor models that lead to a mass-independent leptonic mixing have a vanishing leptogenesis CP asymmetry. Based on symmetry arguments, we prove that in these models the Dirac-neutrino Yukawa coupling combinations relevant for leptogenesis are diagonal in the physical basis where the charged leptons and heavy Majorana neutrinos are diagonal.

Impact of flavor-changing neutral current top quark interactions on BR(t -> bW)

We study the effect that flavor-changing neutral current interactions of the top quark will have on the branching ratio of charged decays of the top quark. We have performed an integrated analysis using Tevatron and B-factories data and with just the further assumption that the Cabibbo-Kobayashi-Maskawa matrix is unitary, we can obtain very restrictive bounds on the strong and electroweak flavor-changing neutral current branching ratios Br(t -> qX)< 4.0x10(-4), where X is any vector boson and a sum in q=u, c is implied.

Torre solar: estudo do rendimento e viabilidade de centrais térmicas solares para produção de energia eléctrica de pequena e média dimensão

O aproveitamento da radiação solar representa um recurso energético extremamente benéfico, quer no âmbito energético, quer no ambiental, contribuindo para a redução das emissões de gases nocivos para a atmosfera. Portugal apresenta uma radiação solar total média anual bastante elevada, colocando-se entre um dos países que apresentam melhores potencialidades para o aproveitamento da energia solar. A torre solar consiste numa estufa com uma determinada extensão com uma chaminé no seu centro e o seu funcionamento baseia-se no aquecimento do ar que circula por baixo da estufa, sendo expelido pela chaminé. Nesta tese é abordado o tema da torre solar e os princípios físicos inerentes ao seu funcionamento. Foi estudado e descrito o método de cálculo de diversos parâmetros e resultados associados ao funcionamento da torre solar. Elaborou-se uma folha de cálculo para obtenção dos valores de simulações de torres com diversas dimensões, tecendo-se conclusões quanto aos resultados e às variações dos mesmos, consoante as alterações de dimensão dos elementos que a constituem. Foram descritos os vários elementos que constituem uma torre solar, bem como as suas características e tipologias. Efectuou-se um estudo com aplicação a um caso real, para se tecer algumas conclusões e comentários relativamente à viabilidade de uma torre solar para a situação em causa. Por fim, com base em todo o trabalho desenvolvido e abordado, foi possível tecer-se algumas conclusões quanto à viabilidade das torres solares.

Genotoxic effects of exposure to formaldehyde in two different occupational settings

Formaldehyde (CH2O), the most simple and reactive aldehyde, is a colorless, reactive and readily polymerizing gas at room temperature (National Toxicology Program [NTP]. It has a pungent suffocating odor that is recognized by most human subjects at concentrations below 1 ppm. Aleksandr Butlerov synthesized the chemical in 1859, but it was August Wilhelm von Hofmann who identified it as the product formed from passing methanol and air over a heated platinum spiral in 1867. This method is still the basis for the industrial production of formaldehyde today, in which methanol is oxidized using a metal catalyst. By the early 20th century, with the explosion of knowledge in chemistry and physics, coupled with demands for more innovative synthetic products, the scene was set for the birth of a new material–plastics. According to the Report on Carcinogens, formaldehyde ranks 25th in the overall U.S. chemical production, with more than 5 million tons produced each year. Formaldehyde annual production rises up to 21 million tons worldwide and it has increased in China with 7.5 million tons produced in 2007. Given its economic importance and widespread use, many people are exposed to formaldehyde environmentally and/or occupationally. Commercially, formaldehyde is manufactured as an aqueous solution called formalin, usually containing 37% by weight of dissolved formaldehyde. This chemical is present in all regions of the atmosphere arising from the oxidation of biogenic and anthropogenic hydrocarbons. Formaldehyde concentration levels range typically from 2 to 45 ppbV (parts per billion in a given volume) in urban settings that are mainly governed by primary emissions and secondary formation.

Learning in higher education: strategies to overcome challenges faced by adult students - lessons drawn from two studies in portugal

Int’l J. of Information and Communication Technology Education, 3(2), 1-14, April-June 2007

Implications of the LHC two-photon signal for two-Higgs-doublet models

We study the implications for two-Higgs-doublet models of the recent announcement at the LHC giving a tantalizing hint for a Higgs boson of mass 125 GeV decaying into two photons. We require that the experimental result be within a factor of 2 of the theoretical standard model prediction, and analyze the type I and type II models as well as the lepton-specific and flipped models, subject to this requirement. It is assumed that there is no new physics other than two Higgs doublets. In all of the models, we display the allowed region of parameter space taking the recent LHC announcement at face value, and we analyze the W+W-, ZZ, (b) over barb, and tau(+)tau(-) expectations in these allowed regions. Throughout the entire range of parameter space allowed by the gamma gamma constraint, the numbers of events for Higgs decays into WW, ZZ, and b (b) over bar are not changed from the standard model by more than a factor of 2. In contrast, in the lepton-specific model, decays to tau(+)tau(-) are very sensitive across the entire gamma gamma-allowed region.