105 research outputs found
Effects of fluoxetine schock loadings in a aerobic granular sludge sequencing batch reactor
Pharmaceuticals have received increasing attention as emerging organic pollutants due to their frequent occurrence in the environment and potential adverse effects on ecossistems and to human health. Pharmaceuticals may not be completely metabolized in the human body and can enter municipal sewage systems as the parent drug and as their “biologically active” metabolites. Some of these compounds cannot be easily removed at wastewater treatment plants (WWTPs) [1]. Fluoxetine (FLX) is a chiral fluorinated pharmaceutical indicated mainly for treatment of depression and is one of the most dispensed drugs in the world. There is a clear evidence of environmental contamination with this drug and its active metabolite norfluoxetine (NFLX) [2]. Granular sludge sequencing batch reactors (SBR) constitute a promising technology for the treatment of effluents containing micropollutants.
The main biological processes occurring in wastewater treatment plants - COD, N and P removal - can be inhibited by these pollutants. This study focused on the effect of FLX on the performance of granular sludge SBR and on the diversity of the microbial population under continuous and intermittent feeding of the compound. The COD removal was not markedly affected by FLX shock loads. Ammonium removal was initially affected but after ca. 20 days of FLX feeding, NH4+ was not detected in the treated effluent – maximum of 0.03 mM – indicating that ammonia oxidizing bacteria (AOB) became adapted to the presence of FLX. Nitrite was also practically not detected in the treated effluent - maximum of 0.01 mM - indicating that nitrite oxidizing bacteria (NOB) were not inhibited by the presence of the FLX, whereas nitrate accumulated in the effluent, indicating that denitrification was affected. Phosphate removal was markedly affected in the beginning of FLX feeding showing a gradual adaptation to the presence of FLX, being practically not detected in the treated effluent (maximum of 0.04 mM) after 70 days. There was no evidence of FLX biodegradation.
Changes in the bacterial community from aerobic granules were examined using denaturing gradient gel electrophoresis (DGGE) of 16S rRNA. Samples taken before starting the shock loadings with FLX clearly shift from other samples. Moreover, two main branches separate the samples taken during continuous FLX feeding from samples taken during intermittent FLX feeding
Trypsin-like serine peptidase profiles in the egg, larval, and pupal stages of Aedes albopictus
BACKGROUND: Aedes albopictus, a ubiquitous mosquito, is one of the main vectors of dengue and yellow fever, representing an important threat to public health worldwide. Peptidases play key roles in processes such as digestion, oogenesis, and metamorphosis of insects. However, most of the information on the proteolytic enzymes of mosquitoes is derived from insects in the adult stages and is often directed towards the understanding of blood digestion. The aim of this study was to investigate the expression of active peptidases from the preimaginal stages of Ae. albopictus. METHODS: Ae. albopictus eggs, larvae, and pupae were analyzed using zymography with susbtrate-SDS-PAGE. The pH, temperature and peptidase inhibitor sensitivity was evaluated. In addition, the proteolytic activities of larval instars were assayed using the fluorogenic substrate Z-Phe-Arg-AMC. RESULTS: The proteolytic profile of the larval stage was composed of 8 bands ranging from 17 to 130 kDa. These enzymes displayed activity in a broad range of pH values, from 5.5 to 10.0. The enzymatic profile of the eggs was similar to that of the larvae, although the proteolytic bands of the eggs showed lower intensities. The pupal stage showed a complex proteolytic pattern, with at least 6 bands with apparent molecular masses ranging from 30 to 150 kDa and optimal activity at pH 7.5. Peptidases from larval instars were active from 10°C to 60°C, with optimal activity at temperatures between 37°C and 50°C. The proteolytic profile of both the larval and pupal stages was inhibited by phenyl-methyl sulfonyl-fluoride (PMSF) and Nα-Tosyl L-lysine chloromethyl ketone hydrochloride (TLCK), indicating that the main peptidases expressed during these developmental stages are trypsin-like serine peptidases. CONCLUSION: The preimaginal stages of Ae. albopictus exhibited a complex profile of trypsin-like serine peptidase activities. A comparative analysis of the active peptidase profiles revealed differential expression of trypsin-like isoforms among the preimaginal stages, suggesting that some of these enzymes are stage specific. Additionally, a comparison of the peptidase expression between larvae from eggs collected in the natural environment and larvae obtained from the eggs of female mosquitoes maintained in colonies for a long period of time demonstrated that the proteolytic profile is invariable under such conditions
Controlo mecânico de infestantes
As infestantes são plantas indesejáveis que crescem juntamente com as plantas cultivadas e que interferem no seu desenvolvimento normal.
As infestantes podem ser uma das principais causas da diminuição do rendimento das culturas, porque competem com elas para o espaço, para a água, luz solar, nutrientes e dióxido de carbono, podem segregar substâncias alelopáticas, ser o meio no qual temporariamente se instalam alguns organismos responsáveis por inúmeras pragas e doenças que atacam as culturas dificultando assim o combate às mesmas, dificultam a colheita quer esta seja manual ou mecanizada, podem contaminar o produto final, depreciando-o e, asseguram a reinfestação para as culturas seguintes.
O controlo de infestantes ter-se-á iniciado quando o homem deixou a de ser nómada e de assegurar as suas necessidades através da colheita de frutos e da caça e passou após a “domesticação“ das espécies animais e vegetais a fazer agricultura, tornando-se sedentário. Portanto, desde o início da agricultura, que o homem tem feito grandes esforços para controlar as plantas infestantes, primeiro à mão, depois com o uso de alguns artefactos, ferramentas e equipamentos para melhorar a eficiência no seu controlo. Hoje existem equipamentos mecânicos sofisticados tal como, substâncias químicas ou biológicas que permitem o seu controlo prevenindo ou retardando a sua germinação ou crescimento.
Interferência das plantas infestantes com a cultura pode gerar perdas significativas, na qualidade e quantidade de alimentos produzidos, desperdiçando enormes quantidades de energia, especialmente não renováveis. Os custos no controlo e os efeitos sobre os rendimentos são muito variáveis, dependendo do agricultor, das espécies de plantas infestantes e da estratégia ou estratégias adoptadas para garantir a eficácia no controlo.
Nas últimas cinco décadas têm vindo a fazer-se significativos avanços científicos e tecnológicos na criação de estratégias para o aumento da eficácia no controlo de infestantes seja mecanicamente, seja através da utilização de substâncias químicas ou biológicas menos tóxicas para o homem, menos agressivas ao meio ambiente, com menores custos de produção e ao mesmo tempo, mais selectivas para as culturas onde são aplicadas.
A alternativa ao controlo químico de infestantes através da aplicação de herbicidas é o controlo mecânico pela utilização de diversas alfaias agrícolas, tais como a charrua de aivecas, a charrua de discos, o escarificador de braços rígidos, o escarificador de braços flexíveis (vibrocultor) e a fresa. O controlo mecânico de infestantes poderá ser levado a cabo também por máquinas de corte, como por exemplo, as gadanheiras. Cortar as infestantes numa fase de desenvolvimento antes da produção de semente evita a sua propagação.
Se o agricultor optar pela sementeira directa como técnica de instalação das culturas, a única alternativa que tem para o controlo de infestantes é a química, mas se optar pelo sistema de mobilização tradicional ou pela mobilização reduzida poderá controlar as infestantes, química e/ou mecanicamente.
A eficácia das diferentes alfaias no controlo de infestantes depende da própria alfaia, da época do ano em que se realiza esse controlo, do estado do solo, das espécies de infestantes presentes e seu estádio de desenvolvimento.
Iremos no presente trabalho, referir os aspectos mais importantes do controlo mecânico de infestantes
Centrosome amplification arises before neoplasia and increases upon p53 loss in tumorigenesis
The uploaded article version is the Epub Ahead of Print version of the article, posted online 8 May 2018. It has been submitted to peer-review.The deposited article version contains attached the supplementary materials within the pdf.Centrosome abnormalities are a typical hallmark of human cancers. However, the origin and dynamics of such abnormalities in human cancer are not known. In this study, we examined centrosomes in Barrett's esophagus tumorigenesis, a well-characterized multistep pathway of progression, from the premalignant condition to the metastatic disease. This human cancer model allows the study of sequential steps of progression within the same patient and has representative cell lines from all stages of disease. Remarkably, centrosome amplification was detected as early as the premalignant condition and was significantly expanded in dysplasia. It was then present throughout malignant transformation both in adenocarcinoma and metastasis. The early expansion of centrosome amplification correlated with and was dependent on loss of function of the tumor suppressor p53 both through loss of wild-type expression and hotspot mutations. Our work shows that centrosome amplification in human tumorigenesis can occur before transformation, being repressed by p53. These findings suggest centrosome amplification in humans can contribute to tumor initiation and progression.Fundação para a Ciência e a Tecnologia–Harvard Medical School Program Portugal grant: (HMSP-CT/SAU-ICT/0075/2009); Liga Portuguesa Contra o Cancro; European Molecular Biology Organization Installation; Sociedade Portuguesa de Gastroenterologia.N/
Recommending Physical Activity to Your Aging Patients? What Clinicians Need to Know to Increase Adherence From the Older Adult Perspective
A wealth of scientific evidence supports that being physically active may prevent or delay the onset of cognitive impairment and dementia. However, a critical barrier is that while most clinicians recommend physical activity (PA) and older adults recognize its health benefits, most older adults fail to regularly practice PA. Thus, it is necessary to explore and disseminate knowledge on how to help clinicians truly partner with people and help them to change their behavior and become more active. Clinical and scientific efforts are underway to establish dose-specific PA recommendations for cognitive brain health. However, an important knowledge gap is how to develop effective strategies to increase PA adherence in aging. To better understand the perspective of older adults, we undertook a mixed-method study on sixty-five sedentary older adults at risk for cognitive decline. Participants answered a questionnaire battery related to PA engagement, and a subcohort participated in a remote focus group. Our findings revealed four main themes: First, age and aging are determinants in PA practice. Second, maintaining both an active mind and autonomy are priorities, but planned PA is not usually related as part of being “active.” Third, motivational challenges in PA engagement were noted. And fourth, they emphasized a call for tailored recommendations. Therefore, we present a multidimensional model of PA adherence to maximize brain health in older adults and suggest a tool kit and key questions to effectively screen sedentary aging adults and translate current guidelines into the needs of the individual by using behavior change strategies
Membrane Cholesterol Regulates Lysosome-Plasma Membrane Fusion Events and Modulates Trypanosoma cruzi Invasion of Host Cells
Trypanosoma cruzi, is the etiological agent of a neglected tropical malady known as Chagas' disease, which affects about 8 million people in Latin America. 30–40% of affected individuals develop a symptomatic chronic infection, with cardiomyopathy being the most prevalent condition. T. cruzi utilizes an interesting strategy for entering cells: T. cruzi enhances intracellular calcium levels, which in turn trigger the exocytosis of lysosomal contents. Lysosomes then donate their membrane for the formation of the parasitophorous vacuole. Membrane rafts, cholesterol-enriched microdomains in the host cell plasma membrane, have also been implicated in T. cruzi invasion process. Since both plasma membrane and lysosomes collaborate in parasite invasion, we decided to study the importance of these membrane domains for lysosomal recruitment and fusion during T. cruzi invasion into host cells. Our results show that drug dependent depletion of plasma membrane cholesterol changes raft organization and induces excessive lysosome exocytosis in the earlier stages of treatment, leading to a depletion of lysosomes near the cell cortex, which in turn compromises T. cruzi invasion. Based on these results, we propose that cholesterol depletion leads to unregulated exocytic events of pre-docked lysosomes, reducing lysosome availability at the cell cortex and consequently compromising T. cruzi infection
Genome-wide association analyses identify new susceptibility loci for oral cavity and pharyngeal cancer
We conducted a genome-wide association study of oral cavity and pharyngeal cancer in 6,034 cases and 6,585 controls from Europe, North America and South America. We detected eight significantly associated loci (P < 5 x 10(-8)), seven of which are new for these cancer sites. Oral and pharyngeal cancers combined were associated with loci at 6p21.32 (rs3828805, HLA-DQB1), 10q26.13 (rs201982221, LHPP) and 11p15.4 (rs1453414, OR52N2-TRIM5). Oral cancer was associated with two new regions, 2p23.3 (rs6547741, GPN1) and 9q34.12 (rs928674, LAMC3), and with known cancer-related loci-9p21.3 (rs8181047, CDKN2B-AS1) and 5p15.33 (rs10462706, CLPTM1L). Oropharyngeal cancer associations were limited to the human leukocyte antigen (HLA) region, and classical HLA allele imputation showed a protective association with the class II haplotype HLA-DRB1*1301-HLA-DQA1*0103-HLA-DQB1*0603 (odds ratio (OR) = 0.59, P = 2.7 x 10(-9)). Stratified analyses on a subgroup of oropharyngeal cases with information available on human papillomavirus (HPV) status indicated that this association was considerably stronger in HPV-positive (OR = 0.23, P = 1.6 x 10(-6)) than in HPV-negative (OR = 0.75, P = 0.16) cancers
O efeito de borda influencia a estrutura da comunidade vegetal em uma floresta tropical seca?
Efeitos de borda são considerados fator-chave na regulação da estrutura de comunidades vegetais em diferentes ecossistemas. Entretanto, apesar dos poucos estudos relacionados, o efeito de borda parece não ser determinante em regiões semiáridas, como a floresta tropical seca brasileira, conhecida como Caatinga. Este estudo testou a hipótese nula de que a comunidade vegetal arbustivo-arbórea não sofre alterações em sua estrutura, riqueza e composição devido ao efeito de borda. Foram instaladas 24 parcelas (20 x 20 m) em um fragmento de Caatinga arbórea, sendo 12 parcelas na borda do fragmento e 12 parcelas no seu interior. A riqueza, abundância e composição das espécies não diferiram estatisticamente entre as parcelas de borda e interior. Os resultados deste estudo corroboram um possível padrão de ambientes semiáridos e contrastam com resultados anteriores de diferentes ambientes, como florestas tropicais úmidas, cerrado e floresta de araucária. Indicam diferenças abruptas entre comunidades vegetais da borda e do interior de fragmentos florestais, sugerindo que a comunidade arbustivo-arbórea da Caatinga não é ecologicamente afetada pela presença de bordas._________________________________________________________________________________________ ABSTRACT: Edge effects are considered a key factor in regulating the structure of plant communities in different ecosystems. However, regardless to few studies, edge influence does not seem to be decisive in semiarid regions such as the Brazilian tropical dry forest known as Caatinga but this issue remains inconclusive. The present study tests the null hypothesis that the plant community of shrubs and trees does not change in its structure due to edge effects. Twenty-four plots (20 x 20 m) were set up in a fragment of Caatinga, in which 12 plots were in the forest edges and 12 plots were inside the fragment. Tree richness, abundance and species composition did not differ between edge and interior plots. The results of this study are in agreement with the pattern previously found for semiarid environments and contrasts with previous results obtained in different environments such as Rainforests, Savanna and Forest of Araucaria, which indicate abrupt differences between the border and interior of the plant communities in these ecosystems, and suggest that the community of woody plants of the Caatinga is not ecologically affected by the presence of edges
Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants
© The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups
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