423 research outputs found
Using nitrogen concentration and isotopic composition in lichens to spatially assess the relative contribution of atmospheric nitrogen sources in complex landscapes
Reactive nitrogen (Nr) is an important driver of global change, causing alterations in ecosystem biodiversity and functionality. Environmental assessments require monitoring the emission and deposition of both the amount and types of Nr. This is especially important in heterogeneous landscapes, as different land-cover types emit particular forms of Nr to the atmosphere, which can impact ecosystems distinctively. Such assessments require high spatial resolution maps that also integrate temporal variations, and can only be feasibly achieved by using ecological indicators. Our aim was to rank land-cover types according to the amount and form of emitted atmospheric Nr in a complex landscape with multiple sources of N. To do so, we measured and mapped nitrogen concentration and isotopic composition in lichen thalli, which we then related to land-cover data. Results suggested that, at the landscape scale, intensive agriculture and urban areas were the most important sources of Nr to the atmosphere. Additionally, the ocean greatly influences Nr in land, by providing air with low Nr concentration and a unique isotopic composition. These results have important consequences for managing air pollution at the regional level, as they provide critical information for modeling Nr emission and deposition across regional as well as continental scales.Supported by project GISA (funded by private companies: GALP, Repsol, APS, AdSA, AICEP, CARBOGAL, EDP, EuroResinas, KIMAXTRA, REN and GENERG; and managed by local authorities: CCDRA, ARSA and Municipalities of Sines, Santiago do Cacém, Grândola, Álcacer do Sal and Odemira. Further support for researchers from FCT-MCTES (SFRH/BPD/75425/2010, SFRH/BPD/109382/2015 and Investigador FCT contract) and EC-H2020 (NitroPortugal 692331)
Measuring and mapping the effectiveness of the European Air Quality Directive in reducing N and S deposition at the ecosystem level
To protect human health and the environment (namely ecosystems), international air quality protocols and guidelines, like the Gothenburg protocol (1999) and the 2001 EU Air Quality Directive (NECD), conveyed national emission ceilings for atmospheric pollutants (Directive 2001/81/EC), including the reduction of sulfur (S) and nitrogen (N) emissions by 2010. However, to what degree this expected reduction in emissions had reflections at the ecosystem level (i.e. pollutant levels reaching and impacting ecosystems and their organisms) remains unknown. Here, we used lichens as ecological indicators, together with reported air and precipitation pollutant concentrations, to determine and map the consequences of the S and N atmospheric emission's reduction, during the implementation of the 2001 Directive (in 2002 and 2011), due primarily to the industrial-sector. The study area is a mixed-land-use industrialized Mediterranean agroforest ecosystem, in southwest Europe. The reduction of S emissions (2002-2011) was reflected at the ecosystem level, as the same S-declining trend was observed in atmospheric measurement stations and lichens alike (-70%), indicating that most S deposited to the ecosystem had an industrial origin. However, this was not the case for N with a slight N-reduction near industrial facilities, but mostly N-deposition in lichens increased in areas dominated by agricultural land-uses. Taken together, these results highlight the importance of going beyond emissions estimation and modeling, to assess the success of the implementation of the NECD in lowering pollutant accumulation in living organisms and their environment. This can only be achieved by measuring pollutant deposition at the ecosystem level (e.g. living organisms). By doing so, we were able to show that the 2001 NECD was successful in reducing S concentrations from Industry, whereas N remains a challenge. Despite the small reduction in N-emissions, deposition into ecosystems did not reflect these changes as agriculture and transport sectors must reduce NH3 and NOx emissions. (C) 2018 Published by Elsevier B.V.The research was supported by project GISA [funded by private companies: GALP, Repsol, APS, AdSA, AICEP, CARBOGAL, EDP, EuroResinas, KIMAXTRA, REN and GENERG; and managed by local authorities: CCDRA, ARSA and Municipalities of Sines, Santiago do Cacem, Grandola, Alcacer do Sal and Odemira]; article preparation was supported by project NitroPortugal [European Union's Horizon 2020 research and innovation programme under grant agreement No 692331]. NitroPortugal is a co-financer for the project Towards INMS, implemented by UN Environment. Concentration of pollutants in precipitation available in the EBAS database has largely been funded by the UN-ECE CLRTAP (EMEP) and through NILU internal resources
Five-Year Outcome in Stroke Patients Submitted to Thrombolysis
BACKGROUND AND PURPOSE:
Little is known on long-term follow-up after thrombolysis in ischemic stroke patients because the majority of studies evaluated outcome at 3 to 12 months. We aimed to assess 5-year outcome after intravenous thrombolysis (IVT).
METHODS:
Cohort study based on the prospective registry of all consecutive ischemic stroke patients submitted to IVT in our Stroke Unit. Five-year outcome, including living settings, functional outcome, stroke recurrence, and mortality, was ascertained by telephonic interviews and additional review of clinical records. Multivariate analyses were performed to identify predictors of outcome and mortality. Excellent outcome was defined as modified Rankin scale 0 to 1.
RESULTS:
Five-year outcome was available for 155/164 patients submitted to IVT. At 5 years, 32.9% of patients had an excellent outcome (95% confidence interval (CI) =25.5-43.3) and mortality was 43.9% (95%CI=36.1-51.7). Increasing age (odds ratio =0.93, 95% CI =0.90-0.97) and increasing National Institute of Health Stroke Scale (NIHSS) 24 h after thrombolysis (odds ratio =0.81, 95% CI =0.74-0.90) were independently associated with a lower likelihood of an excellent 5-year outcome. Age (hazards ratio =1.07, 95% CI =1.03-1.11) and excellent functional outcome 3 months after thrombolysis (hazards ratio =0.28, 95%CI=0.12-0.66) were independently associated with mortality during follow-up.
CONCLUSIONS:
One third of ischemic stroke patients have excellent 5-year outcome after IVT. Younger age, lower NIHSS 24 h after IVT, and excellent 3-month functional outcome are independent predictors of excellent 5-year outcome
Diastolic tolerance to systolic pressures closely reflects systolic performance in patients with coronary heart disease
In animal experiments, elevating systolic pressures induces diastolic dysfunction and may contribute to congestion, a finding not yet translated to humans. Coronary surgery patients (63 ± 8 years) were studied with left ventricular (LV) pressure (n = 17) or pressure-volume (n = 3) catheters, immediately before cardiopulmonary bypass. Single-beat graded pressure elevations were induced by clamping the ascending aorta. Protocol was repeated after volume loading (n = 7). Consecutive patients with a wide range of systolic function were included. Peak isovolumetric LV pressure (LVP(iso)) ranged from 113 to 261 mmHg. With preserved systolic function, LVP elevations neither delayed relaxation nor increased filling pressures. With decreasing systolic function, diastolic tolerance to afterload progressively disappeared: relaxation slowed and filling pressures increased (diastolic dysfunction). In severely depressed systolic function, filling pressures increased even with minor LVP elevations, suggesting baseline load-dependent elevation of diastolic pressures. The magnitude of filling pressure elevation induced in isovolumetric heartbeats was closely and inversely related to systolic performance, evaluated by LVP(iso) (r = -0.96), and directly related to changes in the time constant of relaxation τ (r = 0.95). The maximum tolerated systolic LVP (without diastolic dysfunction) was similarly correlated with LVP(iso) (r = 0.99). Volume loading itself accelerated relaxation, but augmented afterload-induced upward shift of filling pressures (7.9 ± 3.7 vs. 3.0 ± 1.5; P < 0.01). The normal human response to even markedly increased systolic pressures is no slowing of relaxation and preservation of normal filling pressures. When cardiac function deteriorates, the LV becomes less tolerant, responding with slowed relaxation and increased filling pressures. This increase is exacerbated by volume loading
Inv21p12q22del21q22 and intellectual disability
Chromosomal rearrangements are common in humans. Pericentric inversions are among the most frequent aberrations (1-2%). Most inversions are balanced and do not cause problems in carriers unless one of the breakpoints disrupts important functional genes, has near submicroscopic copy number variants or hosts "cryptic" complex chromosomal rearrangements. Pericentric inversions can lead to imbalance in offspring. Less than 3% of Down syndrome patients have duplication as a result of parental pericentric inversion of chromosome 21. We report a family with an apparently balanced pericentric inversion of chromosome 21. The proband, a 23-year-old female was referred for prenatal diagnosis at 16weeks gestation because of increased nuchal translucency. She has a familial history of Down's syndrome and moderate intellectual disability, a personal history of four spontaneous abortions and learning difficulties. Peripheral blood and amniotic fluid samples were collected to perform proband's and fetus' cytogenetic analyses. Additionally, another six family members were evaluated and cytogenetic analysis was performed. Complementary FISH and MLPA studies were carried out. An apparent balanced chromosome 21 pericentric inversion was observed in four family members, two revealed a recombinant chromosome 21 with partial trisomy, and one a full trisomy 21 with an inverted chromosome 21. Array CGH analysis was performed in the mother and the brother's proband. MLPA and aCGH studies identified a deletion of about 1.7Mb on the long arm of inverted chromosome 21q22.11. We believe the cause of the intellectual disability/learning difficulties observed in the members with the inversion is related to this deletion. The recombinant chromosome 21 has a partial trisomy including the DSCR with no deletion. The risk for carriers of having a child with multiple malformations/intellectual disability is about 30% depending on whether and how this rearrangement interferes with meiosis
Cyclodextrin/cellulose hydrogel with gallic acid to prevent wound infection
Cyclodextrin-based hydrogels have been described as suitable for the controlled-release of bioactive molecules to be used as wound dressing. These materials have major advantages, since they gather the hydrogel properties (high degree of swelling and easy manipulation) and the encapsulation ability of cyclodextrins. β-cyclodextrin (β) or hydroxypropyl-β-cyclodextrin (HPβ) was cross-linked (1,4-butanediol diglycidyl ether) with hydroxypropyl methylcellulose under mild conditions. The hydrogels were chemically characterized by swelling degree, FTIR, DSC and contact angle. The gallic acid loading and release was also analysed, as well the antibacterial activity and cytotoxicity of the polymeric networks. The hydrogels obtained were firm and transparent, with good swelling ability. The gel-HPβ had a surface more hydrophilic when compared with the gel-β. Nevertheless, both hydrogels were capable to incorporate gallic acid and sustain the release for 48 h. The antibacterial activity of gallic acid was maintained after its adsorption within the polymeric matrix, as well as, gallic acid effect on fibroblast proliferation. Therefore, gel-β and gel-HPβ conjugated with gallic acid were shown to be a viable option for antibacterial wound dressing.The authors thank the FCT Strategic Projects PEst-OE/EQB/LA0023/2013, PEst-C/CTM/UI0264/2011, the Project "BioHealth-Biotechnology and Bioengineering approaches to improve health quality'', Ref. NORTE-07-0124-FEDER-000027, co-funded by the Programa Operacional Regional doNorte (ON.2-ONovoNorte), QREN, FEDER, and E. Pinho grant (SFRH/BD/62665/2009)
Developmental Defects of Enamel in Primary Teeth and Association with Early Life Course Events: A Study of 6--36 Month old Children in Manyara, Tanzania.
Children with low birth weight show an increased prevalence of developmental defects of enamel in the primary dentition that subsequently may predispose to early childhood caries (ECC).Focusing 6--36 months old, the purpose of this study was to assess the frequency of enamel defects in the primary dentition and identify influences of early life course factors; socio-demographics, birth weight, child's early illness episodes and mothers' perceived size of the child at birth, whilst controlling for more recent life course events in terms of current breastfeeding and oral hygiene. A cross-sectional study was conducted in the high fluoride area of Manyara, northern Tanzania including 1221 child-mother pairs who attended Reproductive and Child Health (RCH) clinics for immunization and/or growth monitoring. After the primary caregivers had completed face to face interviews at the health care facility, children underwent oral clinical examination whereby ECC and developmental defects of enamel were recorded using field criteria. All erupted teeth were examined and the enamel defects were assessed on buccal surfaces according to the modified DDE Index. The prevalence of enamel defects was 33.3%. Diffuse opacities were the most common defects identified (23.1%), followed by hypoplasia (7.6%) and demarcated opacities (5.0%). The most frequently affected teeth were the upper central incisors (29.0% - 30.5%), whereas lower central incisors (4.3% to 4.5%) were least frequently affected. Multiple logistic regression analysis, adjusting for confounding the factors revealed that having normal birth weight (equal or more than 2500 g) associated with lower odds of having enamel hypoplasia [OR 0.22 (95% CI 0.1-0.7)]. No statistically significant association occurred between birth weight and diffuse opacities, demarcated opacities or combined DDE. Children with the history of low birth weight were more likely than their normal birth weight counterparts to present with enamel hypoplasia. In view of the frequent occurrence of enamel defects and the fact that hypoplasia may constitute a risk factor for future ECC, enamel defects should be included as a dental health indicator in epidemiological studies of children in northern Tanzania
Consensus Document on Coding of Cardiac Magnetic Resonance Examinations in Portugal
Um dos obstáculos a uma utilização mais frequente e apropriada da ressonância
magnética cardíaca (RMC) em Portugal tem sido a ausência de códigos específicos que descrevam adequadamente os exames tal como são efetuados actualmente. Este documento de consenso fornece recomendações para a atualização e uniformização dos códigos empregues na RMC. São igualmente feitas recomendações quanto às técnicas e códigos a utilizar nas indicações clínicas mais frequentes
Welfare effects of unbundling under different regulatory regimes in natural gas markets
In this paper, we develop a theoretical model that enriches the literature on the pros and cons of ownership unbundling vis-a`-vis lighter unbundling frameworks in the natural gas markets. For each regulatory framework, we compute equilibrium outcomes when an incumbent firm and a new entrant compete a` la Cournot in the final gas market. We find that the entrant’s contracting conditions in the upstream market and the transmission tariff are key determinants of the market structure in the downstream gas market (both with ownership and with legal unbundling). We also study how the regulator must optimally set transmission tariffs in each of the two unbundling regimes. We conclude that welfare maximizing tariffs often require free access to the transmission network (in both regulatoy regimes). However, when the regulator aims at promoting the break-even of the regulated transmission system operator, the first-best tariff is unfeasible in both regimes. Hence, we study a more realistic set-up, in which the regulator’s action is constrained by the break-even of the regulated firm (the transmission system operator). In this set-up, we find that, for a given transmission tariff, final prices in the downstream market are always higher with ownership unbundling than with legal unbundling.info:eu-repo/semantics/publishedVersio
Microfluidic systems for the analysis of the viscoelastic fluid flow phenomena in porous media
In this study, two microfluidic devices are proposed as simplified 1-D microfluidic analogues of a porous medium. The objectives are twofold: firstly to assess the usefulness of the microchannels to mimic the porous medium in a controlled and simplified manner, and secondly to obtain a better insight about the flow characteristics of viscoelastic fluids flowing through a packed bed. For these purposes, flow visualizations and pressure drop measurements are conducted with Newtonian and viscoelastic fluids. The 1-D microfluidic analogues of porous medium consisted of microchannels with a sequence of contractions/ expansions disposed in symmetric and asymmetric arrangements. The real porous medium is in reality, a complex combination of the two arrangements of particles simulated with the microchannels, which can be considered as limiting ideal configurations. The results show that both configurations are able to mimic well the pressure drop variation with flow rate for Newtonian fluids. However, due to the intrinsic differences in the deformation rate profiles associated with each microgeometry, the symmetric configuration is more suitable for studying the flow of viscoelastic fluids at low De values, while the asymmetric configuration provides better results at high De values. In this way, both microgeometries seem to be complementary and could be interesting tools to obtain a better insight about the flow of viscoelastic fluids through a porous medium. Such model systems could be very interesting to use in polymer-flood processes for enhanced oil recovery, for instance, as a tool for selecting the most suitable viscoelastic fluid to be used in a specific formation. The selection of the fluid properties of a detergent for cleaning oil contaminated soil, sand, and in general, any porous material, is another possible application
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