514 research outputs found
Environmental Stressor Importance: Science versus Media
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152643/1/etc4606.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152643/2/etc4606_am.pd
Metal Toxicity During Short‐Term Sediment Resuspension and Redeposition in a Tropical Reservoir
Billings Complex is the largest water‐storage reservoir in São Paulo, Brazil, and has been contaminated since the 1960s. Periodically, Billings sediments are subjected to currents causing resuspension and subsequent release of metals. A short‐term (4‐h) resuspension was simulated using sediment flux exposure chambers (SeFECs) to better understand the fate, bioavailability, and transport of iron (Fe), manganese (Mn), and zinc (Zn) during these events, as well as possible organism toxicity. Daphnia magna and Hyalella azteca were exposed during the 4‐h resuspension, and were monitored after exposure for survival, growth, and reproduction. Resuspension rapidly deoxygenated the overlying water, decreased the pH, and resulted in elevated dissolved Zn above the US Environmental Protection Agency’s (2002) criteria for acute toxicity (120 µg L–1). However, Zn was scavenged (after 20 h) from solution as new sorption sites formed. Dissolved Mn increased during and after resuspension, with maximum values at 20 h post exposure. An initial release of Fe occurred, likely associated with oxidation of acid‐volatile sulfides, but decreased after 1 h of resuspension. The Fe decrease is likely due to precipitation as oxyhydroxides. No acute toxicity was observed during resuspension; however, mortality of D. magna and H. azteca occurred during the postexposure period. Daphnia magna also exhibited chronic toxicity, with decreased neonate production after exposure. This sublethal effect could lead to decreased zooplankton populations over a longer period in the reservoir. Environ Toxicol Chem 2019;38:1476–1485. © 2019 SETACConceptual model of metal (Me) speciation under different sediment redox states. During bedded conditions (A) metals are mainly bounded as insoluble sulfides or associated with organic carbon (OC). When resuspended (B), sulfide species are oxidized, mobilizing metals (such as Zn) into the overlying water (OW). However, the mobilized metal is scavenged by OC and freshly‐precipitated FexOx. As particles redeposit (C), and are returned to the benthic environment, further oxidation can occur in the aerobic sediment layer releasing Fe. High dissolved Fe concentrations in OW caused acute and chronic toxicity to D. magna. Ingestion of Zn caused growth inhibition and mortality to H. azteca.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149673/1/etc4434_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149673/2/etc4434.pd
Expansion of the core business of traditional media companies in Spain through SVOD services
The strategic importance of the internet for television became evident in the early 2000s, even destabilizing its very concept and finally resulting in convergence towards a profound transformation of the sector. The introduction of global over-the-top (OTT) media services into local markets has led to strategic changes in multimedia groups. This study considers the subscription video-on-demand (SVOD) services of Atresmedia and Mediaset España, the two main traditional media organizations in Spain that form a duopoly in the country’s commercial television sector, with the aim of understanding and evaluating their positioning strategy in this market and the results obtained through the diversification of their core business. Based on an analysis of their content, price, and promotion policies and the results in terms of subscriptions and revenues, slight differences emerge regarding the strategy and scope of these two groups in their own environment in the sector. They compete for customers to achieve growth in the audiovisual market while seeking to retain a cross-media, multiplatform audience, as well as expand their core business of commercial linear television against a background of a reduction of advertising spend on television and the expected increase of hybrid financing models
BAISO - ambiente, storia e paesaggio di un territorio appenninico
Questa pubblicazione intende fornire in modo facilmente comprensibile le informazioni essenziali riguardanti la storia naturale e le vicende umane che nel tempo hanno costruito l'assetto dell'attuale territorio comunale di Baiso (RE). Il volume comprende informazioni su Ambiente naturale, Vegetazione, Patrimonio faunistico, Vicende storiche, Patrimonio architettonico, Particolarit\ue0 del territorio e Nuove opportunit\ue0. Per quanto riguarda quest'ultima parte, sono presentati alla cittadinanza i risultati di uno studio congiunto sui percorsi minerari, in collaborazione con l'Universit\ue0 di Modena e Reggio Emilia e nell'ambito del Progetto Europeo MinLand
Copper transformation, speciation, and detoxification in anoxic and suboxic freshwater sediments
The complex chemistry of copper (Cu) in freshwater sediments at low concentrations is not well understood. We evaluated the transformation processes of Cu added to freshwater sediments under suboxic and anoxic conditions. Freshwater sediments from three sources in Michigan with different characteristics (Spring Creek, River Raisin, and Maple Lake) were spiked with 30 or 60 mg kg-1 Cu and incubated under a nitrogen atmosphere. After 28-d, each treatment subset was amended with organic matter (OM) to promote anoxic conditions and evaluate its effects on Cu speciation. OM addition triggered a shift from suboxic to anoxic conditions, and sequential extractions showed that Cu accordingly shifted from acid-soluble to oxidizable fractions. Extended X-ray absorption fine-structure (EXAFS) spectroscopy revealed that Cu sulfides dominated all anoxic samples except for Spring Creek 30 mg kgxfffd; 1, where Cu(I) was predominantly complexed to thiol groups of OM. Covellite and chalcopyrite (CuFeS2) were the predominant Cu species in nearly all anoxic samples, as determined by Raman spectroscopy, scanning electron microscopy, and X-ray absorption near-edge structure (XANES) spectroscopy. Copper reduction also occurred under suboxic conditions: for two of three sediments, around 80% had been reduced to Cu(I), while the remaining 20% persisted as Cu(II) complexed to OM. However, in the third coarsest (i.e., Spring Creek), around 50% of the Cu had been reduced, forming Cu(I)-OM complexes, while the remainder was Cu(II)-OM complexes. Toxicity tests showed that survival of H. azteca and D. magna were significantly lower in suboxic treatments. Anoxic sediments triggered a near-complete transformation of Cu to sulfide minerals, reducing its toxicity
Primary Absence of Type II Endoleak is A Positive Prognostic Factor against the Risk of Late Conversion of EVAR for AAA
Introduction: The aim of this study is to analyze 12 late conversion to open surgery after Endovascular Repair of
Abdominal Aortic Aneurysms (EVAR) while comparing the follow up of these cases to that of the definitely
successful procedures (absence of surgical conversion, type I or III endoleaks, or presence of type II endoleaks
without any aneurysmal sac enlargement) .
Methods: From a series of over 300 EVAR procedures performed at our department we have selected 215 cases
with a follow up ≥ 6 month and primary technical success (successful deployment of the devices and discharge of
patients without neither type I nor III endoleaks). Based on the final data recorded at the end of the follow up (mean+
IQR: 38.16 months + 41), these cases were divided into three groups: group 1, with 12 cases (5.6%) which needed
surgical conversion in a later stage (5 to 55 months from EVAR); group 2, with 39 cases (18.1%) with type II
endoleaks without aneurysmal sac enlargement; group 3, with 164 cases (76.5%) without endoleaks. The groups
were compared in relation to the following parameters: a) personal data and common atherogenic risk factor, b)
diameter of the aneurysm, c) kind of the proximal fixation of the endograft (suprarenal or infrarenal), d) presence of
endoleaks at the first postoperative check. We have compared the data from the three groups and we have
analyzed them with chi-square test (Χ2).
Results: Personal data and common atherogenic risk factor have proved no significant difference among the
three groups. The incidence of the other three parameters of group 1 was compared with the incidence of these in
groups 2 and 3: the mean pre-operative diameter of the aneurysm results 51 mm in group 1, 54 mm in group 2 and
55 mm in group 3 (not significant); suprarenal fixation of the prosthesis accounts for 50% in group 1, 51% in group 2
and 60% in group 3 (not significant); presence of type II endoleak at the first post-operative check was 41.6% in
group 1, 56.4% in group 2 (not significant) and 9.7% in group 3 (p<0.001, compared to groups 1 and 2).
Conclusion: In the EVAR procedures with primary technical success, the absence of type II endoleak at the first
post-operative check represents a favorable prognostic factor against the risk of late conversion to open repair.
Personal data, common atherogenic risk factor, diameter of the aneurysm and fixing type of the prosthesis don’t
seem to influence the onset of this complication
A randomized, controlled trial on the effectiveness of a proprietary marine lipo-peptide formula vs omega-3 on cytokines profile, anxiety, and pain symptoms in patients with fibromyalgia
Objective: The aim of the present study in an RCT manner (physicians and patients) a novel lipo-peptide marine compound, LD-1227, on physical-, emotional- and functional-related symptomatic complaints in fibromyalgia patients as well as inflammatory cytokines profile and gene expression while using omega-3 as a control group. Methods: The following questionnaire-based or clinical evaluation-based parameters were evaluated: widespread pain index [WPI] patient global impression of change, total tender points [TTP], fibromyalgia impact questionnaire, Beck depression inventory, fatigue severity ratings, cognitive symptom severity, symptom severity score [SSS] and weekly pain intensity ratings. Additional biochemical and gene expression analysis of cytokines (IL6, TNF-α, IL-1β, MCP-1, IL-8, IL-13, IL-1α, and GM-CSF) was performed as well. Data were analyzed with either a paired t-test or the Wilcoxon signed rank test depending on the parametric or non-parametric distribution. Results: Comparing the data from before and after treatment for Group B indicated a statistically significant reduction (p=0.05) in TTP, WPI score, and SSS score. These data suggest a positive effect of a 3-month treatment with the LD-1227 but not omega-3 treatment on Fibromyalgia pain and related anxiety/depressive symptoms. Inspections of HRV and Cytokines found a statistically significant improvement after LD1227 treatment. Unlike the group supplemented with omega-3, the treatment with LD-1227 brought about a decrease in WPI and weekly pain intensity symptoms for the majority of participants. The pre-and post-treatment data for Group B indicated a statistically significant reduction (p=0.05) in TPC, WPI, and SSS scores. No adverse events were reported. Conclusion: These results provide the first indications that the LD-1227 treatment has a statistically significant effect on the recognized fibromyalgia diagnosis metrics of WPI, TTP, and SSS as well on inflammatory markers and parasympathetic balance
Back analysis of the 2014 San Leo Landslide using combined terrestrial laser scanning and 3D distinct element modelling
This is the author accepted manuscript. The final version is available from Springer Verlag via http://dx.doi.org/10.1007/s00603-015-0763-5© 2015 Springer-Verlag Wien Landslides of the lateral spreading type, involving brittle geological units overlying ductile terrains, are a common occurrence in the sandstone and limestone plateaux of the northern Apennines of Italy. The edges of these plateaux are often the location of rapid landslide phenomena, such as rock slides, rock falls and topples. In this paper, we present a back analysis of a recent landslide (February 2014), involving the north-eastern sector of the San Leo rock slab (northern Apennines, Emilia-Romagna Region) which is a representative example of this type of phenomena. The aquifer hosted in the fractured slab, due to its relatively higher secondary permeability in comparison to the lower clayey units leads to the development of perennial and ephemeral springs at the contact between the two units. The related piping erosion phenomena, together with slope processes in the clay-shales have led to the progressive undermining of the slab, eventually predisposing large-scale landslides. Stability analyses were conducted coupling terrestrial laser scanning (TLS) and distinct element methods (DEMs). TLS point clouds were analysed to determine the pre- and post-failure geometry, the extension of the detachment area and the joint network characteristics. The block dimensions in the landslide deposit were mapped and used to infer the spacing of the discontinuities for insertion into the numerical model. Three-dimensional distinct element simulations were conducted, with and without undermining of the rock slab. The analyses allowed an assessment of the role of the undermining, together with the presence of an almost vertical joint set, striking sub-parallel to the cliff orientation, on the development of the slope instability processes. Based on the TLS and on the numerical simulation results, an interpretation of the landslide mechanism is proposed
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