Linearization of a naturally occurring circular protein maintains structure but eliminates hemolytic activity

Cyclotides are a recently discovered family of disulfide rich proteins from plants that contain a circular protein backbone. They are exceptionally stable, as exemplified by their use in native medicine of the prototypic cyclotide kalata B1. The peptide retains uterotonic activity after the plant from which it is derived is boiled to make a medicinal tea. The circular backbone is thought to be in part responsible for the stability of the cyclotides, and to investigate its role in determining structure and biological activity, an acyclic derivative, des-(24-28)-kalata B1, was chemically synthesized and purified. This derivative has five residues removed from the 29-amino acid circular backbone of kalata B1 in a loop region corresponding to a processing site in the biosynthetic precursor protein. Two-dimensional NMR spectra of the peptide were recorded, assigned, and used to identify a series of distance, angle, and hydrogen bonding restraints. These were in turn used to determine a representative family of solution structures. Of particular interest was a determination of the structural similarities and differences between des-(2428)-kalata B1 and native kalata B1. Although the overall three-dimensional fold remains very similar to that of the native circular protein, removal of residues 24-28 of kalata B1 causes disruption of some structural features that are important to the overall stability. Furthermore, loss of hemolytic activity is associated with backbone truncation and linearization.

Identification and comparison of aerobic and denitrifying polyphosphate-accumulating organisms

Two laboratory-scale sequencing batch reactors (SBRs) were operated for enhanced biological phosphorus removal (EBPR) in alternating anaerobic-aerobic or alternating anaerobic-anoxic modes, respectively. Polyphosphate-accumulating organisms (PAOs) were enriched in the anaerobic-aerobic SBR and denitrifying PAOs (DPAOs) were enriched in the anaerobic-aerobic SBR. Fluorescence in situ hybridization (FISH) demonstrated that the well-known PAO, Candidatus Accumulibacter phosphatis was abundant in both SBRs, and post-FISH chemical staining with 4,6-diamidino-2-phenylindol (DAPI) confirmed that they accumulated polyphosphate. When the anaerobic-anoxic SBR enriched for DPAOs was converted to anaerobic-aerobic operation, aerobic uptake of phosphorus by the resident microbial community occurred immediately. However, when the anaerobic-aerobic SBR enriched for PAOs was exposed to one cycle with anoxic rather than aerobic conditions, a 5-h lag period elapsed before phosphorus uptake proceeded. This anoxic phosphorus-uptake lag phase was not observed in the subsequent anaerobic-aerobic cycle. These results demonstrate that the PAOs that dominated the anaerobic-aerobic SBR biomass were the same organisms as the DPAOs enriched under anaerobic-anoxic conditions. (C) 2003 Wiley Periodicals, Inc.

Model-based analysis of anaerobic acetate uptake by a mixed culture of polyphosphate-accumulating and glycogen-accumulating organisms

An increasing number of studies shows that the glycogen-accumulating organisms (GAOs) can survive and may indeed proliferate under the alternating anaerobic/aerobic conditions found in EBPR systems, thus forming a strong competitor of the polyphosphate-accumulating organisms (PAOs). Understanding their behaviors in a mixed PAO and GAO culture under various operational conditions is essential for developing operating strategies that disadvantage the growth of this group of unwanted organisms. A model-based data analysis method is developed in this paper for the study of the anaerobic PAO and GAO activities in a mixed PAO and GAO culture. The method primarily makes use of the hydrogen ion production rate and the carbon dioxide transfer rate resulting from the acetate uptake processes by PAOs and GAOs, measured with a recently developed titration and off-gas analysis (TOGA) sensor. The method is demonstrated using the data from a laboratory-scale sequencing batch reactor (SBR) operated under alternating anaerobic and aerobic conditions. The data analysis using the proposed method strongly indicates a coexistence of PAOs and GAOs in the system, which was independently confirmed by fluorescent in situ hybridization (FISH) measurement. The model-based analysis also allowed the identification of the respective acetate uptake rates by PAOs and GAOs, along with a number of kinetic and stoichiometric parameters involved in the PAO and GAO models. The excellent fit between the model predictions and the experimental data not involved in parameter identification shows that the parameter values found are reliable and accurate. It also demonstrates that the current anaerobic PAO and GAO models are able to accurately characterize the PAO/GAO mixed culture obtained in this study. This is of major importance as no pure culture of either PAOs or GAOs has been reported to date, and hence the current PAO and GAO models were developed for the interpretation of experimental results of mixed cultures. The proposed method is readily applicable for detailed investigations of the competition between PAOs and GAOs in enriched cultures. However, the fermentation of organic substrates carried out by ordinary heterotrophs needs to be accounted for when the method is applied to the study of PAO and GAO competition in full-scale sludges. (C) 2003 Wiley Periodicals, Inc.

Simultaneous nitrification, denitrification, and phosphorus removal in a lab-scale sequencing batch reactor

Simultaneous nitrification and denitrification (SND) via the nitrite pathway and anaerobic-anoxic-enhanced biological phosphorus removal (EBPR) are two processes that can significantly reduce the energy and COD demand for nitrogen and phosphorus removal. The combination of these two processes has the potential of achieving simultaneous nitrogen and phosphorus removal with a minimal requirement for COD. A lab-scale sequencing batch reactor (SBR) was operated in alternating anaerobic-aerobic mode with a low dissolved oxygen (DO) concentration (0.5 mg/L) during the aerobic period, and was demonstrated to accomplish nitrification, denitrification, and phosphorus removal. Under anaerobic conditions, COD was taken up and converted to poly-hydroxyalkanoates (PHAs), accompanied by phosphorus release. In the subsequent aerobic stage, PHA was oxidized and phosphorus was taken up to

Metabolic model for glycogen-accumulating organisms in anaerobic/aerobic activated sludge systems

Glycogen-accumulating organisms (GAO) have the potential to directly compete with polyphosphate-accumulating organisms (PAO) in EBPR systems as both are able to take up VFA anaerobically and grow on the intracellular storage products aerobically. Under anaerobic conditions GAO hydrolyse glycogen to gain energy and reducing equivalents to take up VFA and to synthesise polyhydroxyalkanoate (PHA). In the subsequent aerobic stage, PHA is being oxidised to gain energy for glycogen replenishment (from PHA) and for cell growth. This article describes a complete anaerobic and aerobic model for GAO based on the understanding of their metabolic pathways. The anaerobic model has been developed and reported previously, while the aerobic metabolic model was developed in this study. It is based on the assumption that acetyl-CoA and propionyl-CoA go through the catabolic and anabolic processes independently. Experimental validation shows that the integrated model can predict the anaerobic and aerobic results very well. It was found in this study that at pH 7 the maximum acetate uptake rate of GAO was slower than that reported for PAO in the anaerobic stage. On the other hand, the net biomass production per C-mol acetate added is about 9% higher for GAO than for PAO. This would indicate that PAO and GAO each have certain competitive advantages during different parts of the anaerobic/aerobic process cycle. (C) 2002 Wiley Periodicals, Inc.

Novos modelos de governo na universidade pública em Portugal e competitividade

Em setembro de 2007, o novo regime jurídico das Instituições de Ensino Superior (RJIES), Lei nº 62/2007, de 10 de setembro, introduziu um novo enquadramento de opções de modelos e estruturas de governação nas Instituições de Ensino Superior (IES) em Portugal. O ambiente externo de mudança, comum no contexto europeu, onde as IES adaptam suas acções estratégicas aos desafios da "Declaração de Lisboa", está na ordem do dia. O quadro de opções sobre modelos de governo e de gestão, que são cada vez mais discutidos numa perspectiva de competitividade, permite vantagens e reduz desvantagens comparativas em face das instituições privadas. Se, no contexto europeu, a concepção e o desenho de modelos de governo estão geralmente a convergir, esbatendo as diferenças entre o modelo de gestão das instituições privadas e públicas, em que medida a implementação dos modelos provoca mudanças visíveis no imediato em nível institucional? Em Portugal, a maioria das IES públicas optou pelo modelo tradicional, tendo visto já seus estatutos homologados e publicados em Diário da República. Apenas três instituições optaram pelo modelo fundacional. A presente investigação institucional visa analisar, a partir da metodologia de Clark, as alterações introduzidas nas IES públicas ao nível operacional e de gestão, no sentido de uma universidade empreendedora. Para o efeito, o estudo baseia-se na análise das opções institucionais que as IES enfrentam, ou seja, na possibilidade de escolha entre o tradicional quadro jurídico (direito público) e um novo quadro legal e organizacional (fundações públicas a operar sob o direito privado), a partir da análise dos estatutos entretanto já adotados. Pretende-se ainda integrar a perspectiva do olhar dos elementos externos que passaram recentemente, por via da lei, a integrar os órgãos máximos de governação das universidades públicas: os Conselhos Gerais. Neste artigo vamos efetuar uma análise crítica aos modelos de governo previstos em cada um dos estatutos das IES públicas, não deixando de fazer referência ao modelo fundacional.

Traços de personalidade e religião: meio rural versus meio urbano

As relações do envolvimento religioso com os traços da personalidade em indivíduos do meio rural e indivíduos do meio urbano foram investigadas neste trabalho. Este estudo tem como objectivo o estabelecimento de associações entre traços de personalidade e religião, procedendo a um estudo comparativo entre uma amostra, constituída por indivíduos do meio urbano. A amostra rural foi recolhida no distrito de Portalegre e contou com a participação de 200 sujeitos escolhidos aleatoriamente, tendo sido também recolhida uma amostra de outros 200 sujeitos no meio urbano, em específico na região da Grande Lisboa, de uma forma aleatória. As idades dos participantes estão compreendidas entre os 18 e os 103 anos (M=44,20; DP=19,637), sendo os individuos de ambos os sexos. Procedeu-se a uma caracterização sociodemográfica da amostra e recorreu-se à aplicação de quatro instrumentos, a DUREL (Koening, 1997), o BFI (Oliver & John, 2001), o PANAS (Watson, Clark & Tellegen, 1988) e a PDS (Paulhus, 1998). Os resultados obtidos demonstraram associações sigmificativas entre as dimensões da personalidade, com as dimensões da religiosidade. Verificou-se que os indivíduos com alta religiosidade. Verificou-se que os indivíduos com uma religiosidade apresentam traços mais vincados de amabilidade e de conscienciosidade. Por outro lado verificou-se que os indivíduos com alta religiosidade no meio urbano apresentam um nível mais elevado de neuroticismo e de abertura à experiência do que no meio rural. ABSTRACT: The relation between the religious involvement with the personality traits in individuals from rural and urban environment were investigated in this work . This study aims to establish associations between personality traits and religion, by carrying out a comparative study of a sample consisting of individuals from rural areas and a sample of individuals from urban areas. The rural sample was collected in the district of Portalegre, in which participated 200 individuals randomly chosen, a sample of 200 individuals in the urban area, specifically in the area of Lisbon city, chosen at random, were also collected. The ages of participants are between 18 and 103 years old (M= 44.20, SD=19.637). A social-demographic characterization of the sample was carried out and four measures were used – Durel (Koenig et al., 1997), BFI (Oliver & John, 2001), the PANAS (Watson Clark & Tellegen, 1988) and PDS (Paulhus, 1998). Results showed significant associations between dimensions of personality and dimensions of religiosity. It was found that individuals with a high religiosity have more pronouneed trits of kindness and conscientiousness. Moreover it was found that individuals with high religiosity in urban areas have a higher level of neuroticism and openness to experience than in rural areas.

Personalidade e stresse em militares da Força Aérea Portuguesa: diferenças entre género

RESUMO: A organização militar é uma das mais importantes para qualquer , é uma instituição com regras e valores muito bem definidos, em que factores como a personalidade e o stress terão de ser muito bem avaliados para que se possa integrar uma carreira militar. A amostra estudada foi constituída por 200 militares da Força Aérea Portuguesa, com idade compreendidas entre os 19 e os 52 anos sendo a média de idades 26,3 anos (DP= 5,9). Em estudos anteriores verifiou-se que as diferenças entre géneros são uma condicionante no dia-a-dia de um militar (Lorenzi-Cioldi, 1994). Contudo, Eagly (1987), afirma que a diferença entre géneros tem uma pequena percentagem (5%) contra os 95 % de variabilidade explicada por outros factores na vida militar. Com esta investigação pretendeu-se verificar se existem diferenças entre géneros em relação aos factores básicos da personalidade, stress, afectividade e desejabilidade social, para além de outros aspectos relacionados com estes factores. Utilizaram-se as seguintes medidas de avaliação: o Big Five Factory, BFI (Benet-Martínez & John, 1998), a Paulhus Deception Scale, PDS (Paulhus, 1998), a Positive and Negative Affect Shedule, PANAS (Watson, Clark e Tellenger, 1998) e o Daily Stress Inventory, DSI (Brantley e Glenn, 1989). Conclui-se que ao nível da personalidade, nos factores de extroversão e conscienciosidade as mulheres apresentam valores mais elevados que os homens, em relação ao stress, nos factores competências pessoais, factores ambientais e stressores variados as mulheres obtêm valores mais baixos que os homens. ABSTRACT: The military institution is one of the most important in any country, it has very strict rules and values and therefore factors such as personality and stress must be thoroughly evaluated in order to integrate a military career. The sample under study is constituted by 200 militaries of the Portuguese Air Force, with ages between 19 and 52 years old, being the average 26,3 (DP=5,9). From previous studies it is know that differences in gender constitute a special condition in military personnel day to day life (Lorenzi-Cioldi, 1994). On the other hand, Eagly (1987) states that gender differences represents a small percentage (5%) against 95 % of variance explained by other military life factors. The main focus of this investigation was to determine if there were differences in gender in personality, stress, affect, social desirability and also to study other aspects related to these factors. The measures used were: the Big Five Factory, BFI (Benet-Martínez & John, 1998), the Paulhus Deception Scale, PDS (Paulhus, 1998), the Positive and Negative Affect Schedule, PANAS (Watson, Clark e Tellenger, 1998), the Daily Stress Inventory, DSI (Brantley e Glenn, 1998). It was concluded that on the personality level, women present higher scores on factors such as extroversion and consciousness. On the stress level, when considering factors such as personal competences, environmental factors and varied stressors, women present lower scores than men.

Ação preventiva em problemas visuais de escolares

Apresenta-se abordagem preventiva de problemas visuais de escolares, considerando os níveis de prevenção em Saúde Pública (Leavell e Clark). É destacada a importância da atuação em educação para a saúde na escola, dirigida à promoção da saúde ocular e à prevenção de distúrbios oftalmológicos, buscando a adoção de condutas acertadas do indivíduo, em termos pessoais e coletivos. A linha geral da programação é descrita sucintamente, concluindo pela necessidade da manutenção dos seus propósitos e bom nível, embora já implantada como rotina de serviço.

Ruralização da Lutzomyia intermedia, um provável caso de pré-adaptação

A Lutzomyia intermedia há muito vem sendo encontrada em áreas de colonização antiga. Analisando dados de capturas deste flebotomíneo, com diferentes iscas e em diferentes locais, acredita-se que esta espécie está pré-adaptada a ambientes abertos e a se alimentar em mamíferos, entre eles o homem.

Observações sobre a leishmaniose tegumentar, cinco anos após profilaxia

Em 1974 foram diagnosticados vários casos de leishmaniose tegumentar americana, no Município do Rio de Janeiro, RJ (Brasil). Naquela ocasião, foram usadas como medidas profiláticas o tratamento dos doentes e a dedetização dos domicílios e anexos, resultando na interrupção da transmissão. Com o aparecimento de novos casos, a partir de 1979, foram reestudadas algumas características de uma das localidades (Camorim) do mesmo município. De junho de 1979 a agosto de 1981, foram comprovados nessa localidade 19 casos novos de leishmaniose tegumentar americana (18 humanos e um em cão). Coletaram-se 1.149 flebótomos (11,4% fêmeas e 88,6% machos) com predomínio de Lutzomyia intermedia (95%). De acordo com o estudo dos casos, pressupõe-se que a transmissão tenha ocorrido no domicílio ou peridomicílio. Acredita-se, pois, que na área estudada, as medidas de controle, adotadas em 1974, foram eficientes por um período de aproximadamente quatro anos.