Mangroves as a source of polyethylene terephthalate (PET) degrading bacteria

Polyethylene terephthalate (PET) is one of the most widely used plastics, and its accumulation in the environment has become an issue of great concern. PET wastes constitute a critical source of pollution to the environment, with important impacts on ecosystems and human health. One possibility to address this problem is to identify microorganisms that may be able to naturally degrade the compound for downstream applications. This study investigated the biodegradation of PET films in soil in the presence or absence of mangrove plants, and with or without bioaugmentation with bacterial isolates of the genus Bacillus and Enterococcus. The experiment was performed in an open garden for ten months. At the end of this period, biodegradation assays of PET monomers and intermediate were further performed using bacterial consortia isolated from the soil of the different treatments. Terephthalic acid (TPA) and bis-2-hydroxyethyl terephthalate (BHET) were added to liquid medium as the sole carbon sources and incubated for 10 days at 30oC. Growth of the consortia was monitored by spectrophotometry, and degradation was followed by HPLC analysis of aliquot samples. The preliminary results from gravimetry analysis showed no significant changes in PET films, regardless of the treatment. On the other hand, total degradation of TPA and BHET was observed for all assays independently of treatment. The results suggest that although direct biodegradation of PET may be challenging to accomplish, bacteria capable of degrading the intermediates and monomers of PET are readily available in the natural environment.info:eu-repo/semantics/publishedVersio

The role of dynamical polarization of the ligand to metal charge transfer excitations in {\em ab initio} determination of effective exchange parameters

The role of the bridging ligand on the effective Heisenberg coupling parameters is analyzed in detail. This analysis strongly suggests that the ligand-to-metal charge transfer excitations are responsible for a large part of the final value of the magnetic coupling constant. This permits to suggest a new variant of the Difference Dedicated Configuration Interaction (DDCI) method, presently one of the most accurate and reliable for the evaluation of magnetic effective interactions. This new method treats the bridging ligand orbitals mediating the interaction at the same level than the magnetic orbitals and preserves the high quality of the DDCI results while being much less computationally demanding. The numerical accuracy of the new approach is illustrated on various systems with one or two magnetic electrons per magnetic center. The fact that accurate results can be obtained using a rather reduced configuration interaction space opens the possibility to study more complex systems with many magnetic centers and/or many electrons per center.Comment: 7 pages, 4 figure

The Influence of Obesity in the Autonomic Nervous System Activity in School-Aged Children in Northern Portugal: A Cross-Sectional Study

Introduction: Obesity is one of the most prevalent chronic diseases in childhood, being an important public health issue. Excessive weight has been associated with autonomic dysfunction but the evidence in children is scarce. Therefore, the aim of this study was to assess the effect of overweight and obesity on the autonomic nervous system activity, in children. Material and Methods: Data from a cross-sectional study of 1602 children, aged 7 to 12 years, was used and 858 children were included in the analysis. Body mass index was calculated and classified according to criteria of the World Health Organization (WHO), Centers for Disease Control and Prevention (CDC) and the International Obesity Task Force (IOTF). Body composition was characterized by bioelectrical impedance. Linear regression models were used to determine the association between body mass index, body composition and the autonomic nervous system activity, assessed by pupillometry. Results: Average dilation velocity was higher among children with obesity, according to the CDC and percentage of body fat criteria (ß = 0.053, 95% CI = 0.005 to 0.101 and ß = 0.063, 95% CI = 0.016 to 0.109, respectively). The same trend was observed for WHO and IOTF criteria (ß = 0.045, 95% CI = -0.001 to 0.091, and ß = 0.055, 95% CI = -0.001 to 0.111, respectively). CDC and WHO body mass index z-scores were also positively associated with the values of average dilation velocity (rs = 0.030, p = 0.048; and rs = 0.027, p = 0.042, respectively). Conclusion: Our findings suggest an association between body mass and changes in the autonomic activity, Moreover, this study provides proof of concept for interventions targeting the prevention/treatment of obesity in children that may offer some benefit in re-establishing the balance of the autonomic nervous system, and subsequently preventing the consequences associated with the autonomic nervous system dysfunction

Note on the point-splitting procedure to evaluate vacuum fluctuation in certain cylindrically symmetric backgrounds

We revisit two-point function approaches used to study vacuum fluctuation in wedge-shaped regions and conical backgrounds. Appearance of divergent integrals is discussed and circumvented. The issue is considered in the context of a massless scalar field in cosmic string spacetime.Comment: REVTeX file, 7 page

Manejo dos restos culturais (soqueira) do algodoeiro como ferramenta de combate às pragas.

bitstream/CPATC-2009-09/20523/1/ct-41.pd

Estudos de viabilidade técnica e econômica visando à incubação de empresas: a experiência da Embrapa Informática Agropecuária.

Resumo: Este trabalho apresenta a experiência da Embrapa Informática Agropecuária na elaboração de estudos de viabilidade técnica e econômica, visando à incubação de empresas. Para este fim, foram selecionadas quatro tecnologias desenvolvidas por esta empresa. A metodologia utilizada para o estudo foi constituída de quatro etapas, a saber: treinamento embate, diligência da inovação®, definição do modelo de negócios e estruturação de plano de negócios. Os resultados demonstram que as tecnologias analisadas têm potencial de comercialização através da incubação de empresas de base tecnológica