Response of a scleractinian coral, Stylophora pistillata, to iron and nitrate enrichment

The purpose of this study was to determine whether the addition of iron alone or in combination with nitrate affects growth and photosynthesis of the scleractinian coral, Stylophora pistillata, and its symbiotic dinoflagellates. For this purpose, we used three series of two tanks for a 3-week enrichment with iron (Fe), nitrate (N) and nitrate + iron (NFe). Two other tanks were kept as a control (C). Stock solutions of FeCl3 and NaNO3 were diluted to final concentrations of 6 nM Fe and 2 muM N and continuously pumped from batch tanks into the experimental tanks with a peristaltic pump. Results obtained showed that iron addition induced a significant increase in the areal density of zooxanthellae (ANOVA, p = 0.0013; change from 6.3 +/- 0.7 x 10(5) in the control to 8.5 +/- 0.6 x 10(5) with iron). Maximal gross photosynthetic rates normalized per surface area also significantly increased following iron enrichment (ANOVA, p = 0.02; change from 1.23 +/- 0.08 for the control colonies to 1.81 +/- 0.24 mu mol O-2 cm(-2) h(-1) for the iron-enriched colonies). There was, however, no significant difference in the photosynthesis normalized on a per cell basis. Nitrate enrichment alone (2 muM) did not significantly change the zooxanthellae density or the rates of photosynthesis. Nutrient addition (both iron and nitrogen) increased the cell-specific density of the algae (CSD) compared to the control (G-test, p = 0.3 x 10(-9)), with an increase in the number of doublets and triplets. CSD was equal to 1.70 +/- 0.04 in the Fe-enriched colonies, 1.54 +/- 0.12 in the N- and NFe-enriched colonies and 1.37 +/- 0.02 in the control. Growth rates measured after 3 weeks in colonies enriched with Fe, N and NFe were 23%, 34% and 40% lower than those obtained in control colonies (ANOVA. p = 0.011). (C) 2001 Elsevier Science B.V. All rights reserved.

Laboratory evaluation of two native fishes from tropical North Queensland as biological control agents of subterranean Aedes aegypti

The ability of 2 freshwater fishes, eastern rainbow fish Melanotaenia splendida splendida and fly-specked hardyhead Craterocephalus stercusmuscarum stercusmuscarum. native to North Queensland to prey on immature Aedes aegypti was evaluated under laboratory conditions. The predation efficiency of the 2 species was compared to the exotic guppy, Poecilia reticulata, which is commonly used as a biological control agent of mosquito larvae. Of the 3 fish species tested, M. s. splendida was shown to be the most promising agent for the biological control of Ae. aegypti that breed in wells. Melanotaenia s. splendida consumed significantly greater numbers of immature Ae. aegypti than P. reticulata, irrespective of developmental stage or light conditions. Unlike C. s. stercusmuscarum, M, s. splendida could be handled, transported, and kept in captivity for extended periods with negligible mortality. However, M. s. splendida was also an efficient predator of Litoria caerulea tadpoles, a species of native frog found in wells during the dry season. This result may limit the usefulness of M. s. splendida as a biological control agent of well-breeding Ae. aegypti and suggests that predacious copepods, Mesocyclops spp., are more suitable. However, the use of M. s. splendida as a mosquito control agent in containers that are unlikely to support frog populations (e.g., aquaculture tanks and drinking troughs) should be given serious consideration.

Commercial-in-confidence: An obituary to transparency?

This article addresses the issue of accountability and transparency in relation to the use of commercial-in-confidence clauses to withhold information. The issue is contentious. On the one hand some like the Senate Finance and Public Administration Reference Committee (SFPARC) argue that: 'Put simply there can be no accountability if there is no information' (SFPARC 2000). On the other hand, an alternative view is: 'I think that the sanctity of contract... [is] a fundamental pillar of our legal system, and if private businesses enter into contracts with governments that specify confidentiality, then that ought to be respected' (Paterson 1999). This paper is an abridged version of a keynote address to CPA Australia (Queensland Division) Audit Intensive Day 2000, Brisbane Hilton, 10 November 2000.

Towards a blood-stage vaccine for malaria: Are we following all the leads?

Although the malaria parasite was discovered more than 120 years ago, it is only during the past 20 years, following the cloning of malaria genes, that we have been able to think rationally about vaccine design and development. Effective vaccines for malaria could interrupt the life cycle of the parasite at different stages in the human host or in the mosquito. The purpose of this review is to outline the challenges we face in developing a vaccine that will limit growth of the parasite during the stage within red blood cells - the stage responsible for all the symptoms and pathology of malaria. More than 15 vaccine trials have either been completed or are in progress, and many more are planned. Success in current trials could lead to a vaccine capable of saving more than 2 million lives per year.

Pragmatic solidarism and the dilemmas of humanitarian intervention

The theory and practice of humanitarian intervention in the 1990s has produced a series of seemingly intractable dilemmas. Why do states act in some cases and not others? How are we to evaluate the legitimacy of particular acts? This article introduces a new perspective on these questions informed by a combination of pragmatism and solidarism. It argues that although the search for criteria that may be used to judge the legitimacy and efficacy of humanitarian intervention may be a futile one, it is possible to think about a politics of legitimate humanitarian intervention. Such a politics may be based on three key insights drawn from pragmatism: the dialogic construction of moral knowledge, the fallibility of knowledge, and the priority of democracy over philosophy. The article discusses how such a pragmatic solidarism may be used to interrogate the quest for legitimising criteria and to build a new politics of humanitarian intervention.

On the effect of tracer density on axial dispersion in a batch oscillatory baffled column

In this paper, we report our modelling evaluation on the effect of tracer density on axial dispersion in a batch oscillatory baffled column (OBC). Tracer solution of potassium nitrite, its specific density ranged from 1.0 to 1.5, was used in the study, and was injected to the vertical column from either the top or bottom. Local concentration profiles are measured using conductivity probes at two locations along the height of the column. Using the experimental measured concentration profiles together with both 'Tank-in-Series' and 'Plug Flow with Axial Dispersion' models, axial dispersion coefficients were determined and used to describe the effect of specific tracer density on mixing in the OBC. The results showed that the axial dispersion coefficients evaluated by the two models are very similar in both magnitudes and trends, and the range of variations in such coefficients is generally larger for the bottom injection than for the top one. Empirical correlations linking the mechanical energy for mixing, the specific density of tracer and axial dispersion coefficient were established. Using these correlations, we identified the enhancements of up to 269% on axial dispersion for various specific tracer densities. (C) 2002 Elsevier Science B.V. All rights reserved.

Tracing the fate of N-15-enriched feed in an intensive shrimp system

The fate of N-15-nitrogen-enriched formulated feed fed to shrimp was traced through the food web in shallow, outdoor tank systems (1000 1) stocked with shrimp. Triplicate tanks containing shrimp water with and without sediment were used to identify the role of the natural biota in the water column and sediment in processing dietary nitrogen (N). A preliminary experiment demonstrated that N-15-nitrogen-enriched feed products could be detected in the food web. Based on this, a 15-day experiment was conducted. The ammonium (NH4+) pool in the water column became rapidly enriched (within one day) with N-15-nitrogen after shrimp were fed N-15-enriched feed. By day 15, 6% of the added N-15-nitrogen was in this fraction in the 'sediment' tanks compared with 0.4% in the 'no sediment' tanks. The particulate fraction in the water column, principally autotrophic nanoflagellates, accounted for 4-5% of the N-15-nitrogen fed to shrimp after one day. This increased to 16% in the 'no sediment' treatment, and decreased to 2% in the 'sediment' treatment by day 15. It appears that dietary N was more accessible to the phytoplankton community in the absence of sediment. The difference is possibly because a proportion of the dietary N was buried in the sediment in the 'sediment' treatment, making it unavailable to the phytoplankton. Alternatively, the dietary N was retained in the NH4+ pool in the water column since phytoplankton growth, and hence, N utilization was lower in the 'sediment' treatment. The lower growth of phytoplankton in the 'sediment' treatment appeared to be related to higher turbidity, and hence, lower light availability for growth. The percentage N-15-nitrogen detected in the sediment was only 6% despite the high capacity for sedimentation of the large biomass of plankton detritus and shrimp waste. This suggests rapid remineralization of organic waste by the microbial community in the sediment resulting in diffusion of inorganic N sources into the water column. It is likely that most of the dietary N will ultimately be removed from the tank system by water discharges. Our study showed that N-15-nitrogen derived from aquaculture feed can be processed by the microbial community in outdoor aquaculture systems and provides a method for determining the effect of dietary N on ecosystems. However, a significant amount of the dietary N was not retained by the natural biota and is likely to be present in the soluble organic fraction. (C) 2002 Elsevier Science B.V. All rights reserved.

Modelling the activated sludge flocculation process combining laser light diffraction particle sizing and population balance modelling (PBM)

A technique based on laser light diffraction is shown to be successful in collecting on-line experimental data. Time series of floc size distributions (FSD) under different shear rates (G) and calcium additions were collected. The steady state mass mean diameter decreased with increasing shear rate G and increased when calcium additions exceeded 8 mg/l. A so-called population balance model (PBM) was used to describe the experimental data, This kind of model describes both aggregation and breakage through birth and death terms. A discretised PBM was used since analytical solutions of the integro-partial differential equations are non-existing. Despite the complexity of the model, only 2 parameters need to be estimated: the aggregation rate and the breakage rate. The model seems, however, to lack flexibility. Also, the description of the floc size distribution (FSD) in time is not accurate.

Control of Aedes vectors of dengue in three provinces of Vietnam by use of Mesocyclops (Copepoda) and community-based methods validated by entomologic, clinical, and serological surveillance

We describe remarkable success in controlling dengue vectors, Aedes aegypti (L.) and Aedes albopictus (Skuse), in 6 communes with 11,675 households and 49,647 people in the northern provinces of Haiphong, Hung Yen, and Nam Dinh in Vietnam. The communes were selected for high-frequency use of large outdoor concrete tanks and wells. These were found to be the source of 49.6-98.4% of Ae. aegypti larvae, which were amenable to treatment with local Mesocyclops, mainly M. woutersi Van der Velde, M. aspericornis (Daday) and M. thermocyclopoides Harada. Knowledge, attitude, and practice surveys were performed to determine whether the communities viewed dengue and dengue hemorrhagic fever as a serious health threat; to determine their knowledge of the etiology, attitudes, and practices regarding control methods including Mesocyclops; and to determine their receptivity to various information methods. On the basis of the knowledge, attitude, and practice data, the community-based dengue control program comprised a system of local leaders, health volunteer teachers, and schoolchildren, supported by health professionals. Recycling of discards for economic gain was enhanced, where appropriate, and this, plus 37 clean-up campaigns, removed small containers unsuitable for Mesocyclops treatment. A previously successful eradication at Phan Boi village (Hung Yen province) was extended to 7 other villages forming Di Su commune (1,750 households) in the current study. Complete control was also achieved in Nghia Hiep (Hung Yen province) and in Xuan Phong (Nam Dinh province); control efficacy was greater than or equal to 99.7% in the other 3 communes (Lac Vien in Haiphong, Nghia Dong, and Xuan Kien in Nam Dinh). Although tanks and wells were the key container types of Ae. aegypti productivity, discarded materials were the source of 51% of the standing crop of Ae. albopictus. Aedes albopictus larvae were eliminated from the 3 Nam Dinh communes, and 86-98% control was achieved in the other 3 communes. Variable dengue attack rates made the clinical and serological comparison of control and untreated communes problematic, but these data indicate that clinical surveillance by itself is inadequate to monitor dengue transmission.

Carreiras p??blicas em uma ordem democr??tica: entre os modelos burocr??tico e gerencial

Refletindo sobre modelo de carreira mais adequado para a Administra????o P??blica nesta era de economia globalizada e de maiores exig??ncias de efici??ncia e flexibilidade na gest??o dos aparatos governamentais, questiona-se aqui a id??ia de que o modelo burocr??tico deva ser substitu??do pelo modelo gerencial. Considerando essa id??ia apenas parcialmente verdadeira, nossa argumenta????o vai na seguinte dire????o: como a burocracia ?? a forma espec??fica de organiza????o do aparato administrativo do Estado de Direito, este modelo n??o pode ser rejeitado, sob pena de comprometimento desse Estado. Mas ele precisa ser flexibilizado, superando e reduzindo o formalismo excessivo e a rigidez que sua realiza????o hist??rica possa ter gerado nos diferentes pa??ses. Igualmente, deve ser aperfei??oado em seus mecanismos de controle, at?? como condi????o para sua manuten????o eficaz nos governos democr??ticos contempor??neos.

Terceiro setor e pol??ticas p??blicas

Te??ricos apontam um estreitamento nas rela????es das entidades do terceiro setor com o Estado. Esta aproxima????o, numa perspectiva internacional, est?? inserida no que se convencionou chamar crise do Estado provedor e, portanto, na busca por modelos alternativos de implementa????o de pol??ticas sociais. No ??mbito nacional, a expans??o do terceiro setor ??, em parte, fruto da redemocratiza????o do pa??s, com a prolifera????o e o amadurecimento de iniciativas da sociedade civil. Este trabalho pretende contribuir para a reflex??o sobre o contexto onde surgem e se desenvolvem essas rela????es. Parece-nos que lan??ar luz sobre a id??ia de parceria pode colaborar na compreens??o das potencialidades e limites desse modelo de coopera????o intersetorial.

Acoplamentos: um estudo sobre a intera????o entre humanos e computadores

Este estudo investiga a intera????o dos humanos com os computadores pessoais. A partir dos inc??modos produzidos por esses encontros, na primeira parte estuda-se a produ????o da m??quina ???amig??vel??? ??? que insinua compara????es com a mente humana ??? e seus fortes efeitos nas transforma????es culturais do final do s??culo XX. Na segunda parte do trabalho, a partir de entrevistas de trabalhadores falando sobre sua aprendizagem b??sica do uso de computadores pessoais, faz-se uma an??lise das principais concep????es sobre a rela????o homem-t??cnica que est??o influenciando a intera????o humano-computador. Com isso fica evidenciado o papel do computador na crise do sujeito moderno, e afirma-se a necessidade de se pensar a subjetividade para al??m da cl??ssica divis??o sujeito-objeto, homem m??quina, natureza-artif??cio... o que aponta para a id??ia de acoplamentos flex??veis entre humanos e computadores e pede por uma no????o de aprendizagem que acolha a cria????o de problemas como seu aspecto mais rico.

Fundamentos para uma pol??tica de carreiras no contexto da reforma gerencial

Com o advento da administra????o gerencial no ??mbito do aparelho do Estado, em complementa????o ?? administra????o burocr??tica, verifica-se certa turbul??ncia na gest??o de pessoal na administra????o p??blica, decorrente da s??bita aus??ncia de fundamentos conceituais s??lidos que permitam pensar a administra????o do capital humano do Estado em um contexto de transforma????o. Este artigo procura estabelecer as bases para a recupera????o destes fundamentos, propondo tr??s crit??rios de design de carreiras: a estrutura de incentivos, os mecanismos de governan??a e a gest??o do conhecimento. Em seguida, exemplifica-se a utiliza????o destes crit??rios pela an??lise de seis temas pr??prios ?? discuss??o sobre carreiras no servi??o p??blico: remunera????o, sele????o, recrutamento e desenvolvimento, mobilidade, promo????o, carreiras para ag??ncias executivas e controle social da burocracia.

Problemas e impasses da carreira p??blica no Brasil: a experi??ncia dos gestores governamentais na administra????o p??blica federal

O presente trabalho tem como objetivo discutir os limites da inser????o da carreira dos Especialistas em Pol??ticas P??blicas e Gest??o Governamental na Administra????o P??blica Federal Brasileira. Nossa tese central ?? que os gestores governamentais, apontados pelo Plano Diretor de Reforma do Estado como fundamentais para o processo de moderniza????o do aparelho do Estado brasileiro, na pr??tica, em seu conjunto, n??o est??o desempenhando fun????es estrat??gicas devido a aus??ncia de uma proposta de inser????o planejada dessa carreira da Administra????o P??blica. Para abordar a tese desse trabalho, confrontamos o projeto de cria????o da carreira no Brasil (seus fundamentos e perspectivas) com as an??lises que exploram a complexa intera????o entre o Sistema Pol??tico e a Administra????o P??blica Federal no Brasil e com a literatura internacional que analisa o processo de reforma da administra????o superior (High Civil Services) nos pa??ses da OCDE. Realizarmos tamb??m entrevistas com alguns membros ativos da carreira para averiguar como eles pensam a pr??pria carreira, sua institucionaliza????o e inser????o na Administra????o P??blica Brasileira.

Vendas de bebidas alcóolicas : questões (im)pertinentes

O objetivo deste estudo é analisar a disponibilidade e o acesso à bebida alcoólica num bairro da cidade de Vitória/ES. Os dados foram obtidos através de pesquisa de campo na região selecionada utilizando a observação simples e a entrevista através da aplicação de questionários numa amostra de 10% dos estabelecimentos encontrados. Os pontos de venda funcionam 7 dias por semana; 68,8% vendem a credito e a um preço médio de R$ 0,41 (a dose de cachaça). 93,8% dos entrevistados não solicitam documento de identidade ao cliente antes de lhe vender bebidas. A relação entre número de moradias e número de pontos de venda foi de 3:1. A alta concentração de estabelecimentos que vendem bebidas alcoólicas no bairro aponta para a necessidade de pensar o entorno (regiões vizinhas) da mesma. Estas regiões envolvem áreas marginalizadas onde ocorre tráfico de drogas, fazendo da região estudada uma área importante para o comércio, pela facilidade de acesso aos outros bairros adjacentes da cidade.