58 research outputs found

    Sediment geochemistry of streams draining abandoned lead / zinc mines in central Wales: the Afon Twymyn

    Get PDF
    Purpose Despite the decline of metal mining in the UK during the early 20th century, a substantial legacy of heavy metal contamination persists in river channel and floodplain sediments. Poor sediment quality is likely to impede the achievement of ’good’ chemical and ecological status for surface waters under the European Union Water Framework Directive. This paper examines the environmental legacy of the Dylife lead/zinc mine in the central Wales mining district. Leachable heavy metal concentrations in the bed sediments of the Afon Twymyn are established and the geochemical partitioning, potential mobility and bioavailability of sediment-associated heavy metals are established. Materials and methods Sediment samples were collected from the river bed and dry-sieved into two size fractions (<63 μm and 64–2,000 μm). The fractionated samples were then subjected to a sequential extraction procedure to isolate heavy metals (Pb, Zn, Cu, Cd, Fe, Mn) in three different geochemical phases. Sediment samples were then analysed for heavy metals using ICP-AES. Results and discussion The bed sediment of the Afon Twymyn is grossly polluted with heavy metals. Within the vicinity of the former mine, Pb concentrations are up to 100 times greater than levels reported to have deleterious impacts on aquatic ecology. Most heavy metals exist in the most mobile easily exchangeable and carbonate-bound geochemical phases, potentially posing serious threats to ecological integrity and constituting a significant, secondary, diffuse source of pollution. Metal concentrations decrease sharply downstream of the former mine, although there is a gradual increase in the proportion of readily extractable Zn and Cd. Conclusions Implementation of sediment quality guidelines is important in order to achieve the aims of the Water Framework Directive. Assessments of sediment quality should include measurements of background metal concentrations, river water physico-chemistry and, most importantly, metal mobility and potential bioavailability. Uniformity of sediment guidelines throughout Europe and flexibility of targets with regard to the most heavily contaminated mine sites are recommended

    Epidemiology of Streptococcus pneumoniae and Staphylococcus aureus colonization in healthy Venezuelan children

    Get PDF
    Streptococcus pneumoniae and Staphylococcus aureus cause significant morbidity and mortality worldwide. We investigated both the colonization and co-colonization characteristics for these pathogens among 250 healthy children from 2 to 5 years of age in Merida, Venezuela, in 2007. The prevalence of S. pneumoniae colonization, S. aureus colonization, and S. pneumoniae–S. aureus co-colonization was 28%, 56%, and 16%, respectively. Pneumococcal serotypes 6B (14%), 19F (12%), 23F (12%), 15 (9%), 6A (8%), 11 (8%), 23A (6%), and 34 (6%) were the most prevalent. Non-respiratory atopy was a risk factor for S. aureus colonization (p = 0.017). Vaccine serotypes were negatively associated with preceding respiratory infection (p = 0.02) and with S. aureus colonization (p = 0.03). We observed a high prevalence of pneumococcal resistance against trimethoprim–sulfamethoxazole (40%), erythromycin (38%), and penicillin (14%). Semi-quantitative measurement of pneumococcal colonization density showed that children with young siblings and low socioeconomic status were more densely colonized (p = 0.02 and p = 0.02, respectively). In contrast, trimethoprim–sulfamethoxazole- and multidrug-resistant-pneumococci colonized children sparsely (p = 0.03 and p = 0.01, respectively). Our data form an important basis to monitor the future impact of pneumococcal vaccination on bacterial colonization, as well as to recommend a rationalized and restrictive antimicrobial use in our community

    Probing the roles of LRR RLK genes in Arabidopsis thaliana roots using a custom T-DNA insertion set

    Get PDF
    Leucine-rich repeat receptor-like protein kinases (LRR RLKs) represent the largest group of Arabidopsis RLKs with approximately 235 members. A minority of these LRR RLKs have been assigned to diverse roles in development, pathogen resistance and hormone perception. Using a reverse genetics approach, a collection of homozygous T-DNA insertion lines for 69 root expressed LRR RLK genes was screened for root developmental defects and altered response after exposure to environmental, hormonal/chemical and abiotic stress. The obtained data demonstrate that LRR RLKs play a role in a wide variety of signal transduction pathways related to hormone and abiotic stress responses. The described collection of T-DNA insertion mutants provides a valuable tool for future research into the function of LRR RLK genes

    Efeitos do treinamento muscular inspiratório em universitários tabagistas e não tabagistas

    Get PDF
    O hábito de fumar pode reduzir a capacidade aeróbica, aumentar a resistência ao fluxo aéreo e afetar a função dos músculos respiratórios. O objetivo deste estudo foi comparar os efeitos do Treinamento Muscular Inspiratório (TMI) entre dois grupos: tabagistas e não tabagistas. Participaram 44 voluntários universitários, divididos em dois grupos: tabagistas (GT), composto por 20 indivíduos (25,60±7,01 anos) e não tabagistas, constituindo o Grupo Controle (GC), composto por 24 voluntários (24,08±7,52 anos). Ambos os grupos foram submetidos ao TMI, por meio do uso do manovacuômetro aneroide, com duração de 6 semanas, sendo 3 sessões semanais, totalizando 18 sessões. Os resultados mostraram diferença estatisticamente significativa (p<0,05) pós-TMI no GC para as variáveis: Pressão Inspiratória Máxima (PImáx), Pico de Fluxo Expiratório (PFE), Pressão Arterial Média ao repouso (PAM pré-TC6) e Teste de Caminhada de Seis Minutos (TC6). No GT, houve diferença estatisticamente significativa pós-TMI para as variáveis: PImáx, PFE, TC6 e saturação periférica de oxigênio após o TC6 (SpO2 pós-imediata). A comparação das médias das variáveis entre GT e GC mostrou diferença estatisticamente significativa no pós-TMI para as variáveis PImáx e PFE. A variável TC6 não apresentou diferença estatisticamente significativa. Conclui-se que o TMI proporcionou um aumento significativo da força muscular inspiratória, melhora da função pulmonar e melhora do desempenho físico nos indivíduos estudados

    Predictions for the future of kallikrein-related peptidases in molecular diagnostics

    Get PDF
    Kallikrein-related peptidases (KLKs) form a cancer-related ensemble of serine proteases. This multigene family hosts the most widely used cancer biomarker that is PSA-KLK3, with millions of tests performed annually worldwide. The present report provides an overview of the biomarker potential of the extended KLK family (KLK1-KLK15) in various disease settings and envisages approaches that could lead to additional KLK-driven applications in future molecular diagnostics. Particular focus is given on the inclusion of KLKs into multifaceted cancer biomarker panels that provide enhanced diagnostic, prognostic and/or predictive accuracy in several human malignancies. Such panels have been described so far for prostate, ovarian, lung and colorectal cancers. The role of KLKs as biomarkers in non-malignant disease settings, such as Alzheimer’s disease and multiple sclerosis, is also commented upon. Predictions are given on the challenges and future directions regarding clinically oriented KLK research

    Intersection of phosphate transport, oxidative stress and TOR signalling in Candida albicans virulence

    Get PDF
    Phosphate is an essential macronutrient required for cell growth and division. Pho84 is the major high-affinity cell-surface phosphate importer of Saccharomyces cerevisiae and a crucial element in the phosphate homeostatic system of this model yeast. We found that loss of Candida albicans Pho84 attenuated virulence in Drosophila and murine oropharyngeal and disseminated models of invasive infection, and conferred hypersensitivity to neutrophil killing. Susceptibility of cells lacking Pho84 to neutrophil attack depended on reactive oxygen species (ROS): pho84-/- cells were no more susceptible than wild type C. albicans to neutrophils from a patient with chronic granulomatous disease, or to those whose oxidative burst was pharmacologically inhibited or neutralized. pho84-/- mutants hyperactivated oxidative stress signalling. They accumulated intracellular ROS in the absence of extrinsic oxidative stress, in high as well as low ambient phosphate conditions. ROS accumulation correlated with diminished levels of the unique superoxide dismutase Sod3 in pho84-/- cells, while SOD3 overexpression from a conditional promoter substantially restored these cells’ oxidative stress resistance in vitro. Repression of SOD3 expression sharply increased their oxidative stress hypersensitivity. Neither of these oxidative stress management effects of manipulating SOD3 transcription was observed in PHO84 wild type cells. Sod3 levels were not the only factor driving oxidative stress effects on pho84-/- cells, though, because overexpressing SOD3 did not ameliorate these cells’ hypersensitivity to neutrophil killing ex vivo, indicating Pho84 has further roles in oxidative stress resistance and virulence. Measurement of cellular metal concentrations demonstrated that diminished Sod3 expression was not due to decreased import of its metal cofactor manganese, as predicted from the function of S. cerevisiae Pho84 as a low-affinity manganese transporter. Instead of a role of Pho84 in metal transport, we found its role in TORC1 activation to impact oxidative stress management: overexpression of the TORC1-activating GTPase Gtr1 relieved the Sod3 deficit and ROS excess in pho84-/- null mutant cells, though it did not suppress their hypersensitivity to neutrophil killing or hyphal growth defect. Pharmacologic inhibition of Pho84 by small molecules including the FDA-approved drug foscarnet also induced ROS accumulation. Inhibiting Pho84 could hence support host defenses by sensitizing C. albicans to oxidative stress

    A SmartBed for Non-obtrusive Physiological Monitoring During Sleep: The LAID Project

    No full text
    The individual experience of inadequate or insufficient sleep is one of the most common health issues in the industrialized world. The 65% of Italian population reports disturbed sleep experiences, while chronic sleep disorders affect about 10% of the population. The people with inadequate and unsatisfactory sleep often suffers drowsiness during the day associated with both somatic and mental disorders. For these reasons, the systematic and continuative monitoring of sleep is one of the main objectives in preventive, personalized and participatory sleep medicine. The purpose of this paper is to describe the architecture of a “smart mattress’’ (SmartBed) that is the main outcome of the Italian R&amp;D project called LAID. SmartBed will be able to non-obtrusively collect physiological and environmental parameters and signals, to processing them and to provide information about the quality of sleep, the levels of stress, and more generally the well-being of an individual. Specifically, SmartBed will be able to estimate data relating to cardiorespiratory activity, movements, body position, snoring and environmental parameters. SmartBed aims to obtain a continuative and ecological assessment of sleep and well-being of a person, in order to improve his quality of life. SmartBed will be a fundamental tool for carrying out both longitudinal and epidemiological studies on the quality of sleep and life on general population
    corecore