3,128 research outputs found
Exploring the Acceptability of an Environmental Education Program for Youth in Rural Areas: ECOCIDADANIA Project
Background: There has been a growing interest in environmental education programs to improve environmental awareness and behavior change among school-aged youth. Yet, assessment of the approaches aligned with citizen science principles emphasizing community participation and empowerment is scarce. The present study aimed to explore the acceptability of the “ECOCIDADANIA” environmental education program targeted at youth in rural areas. Methods: The program was applied for two years in the municipality of Gouveia, and it involved nature walks methodologies combined with citizen science. A total of 107 students participated in the program. Eighteen participants (13 youth and 5 teachers) were selected as key informants, and semistructured interviews were conducted to assess the appropriateness of the intervention and the perceived benefits. Results: The program was demonstrated to be acceptable to youth and teachers, and its benefits included increasing students’ knowledge, skills and self-efficacy, discovering the territory, promoting environmental awareness, strengthening social relationships between peers and educators, and contributing to the promotion of individual and collective well-being. All the participants were satisfied with the program’s activities and recommend its continuation in the school context. Conclusions: Programs of this nature could foster environmental activism and enhance environmental sustainability at the local level, which reinforces the entrepreneurship profile of the youth.info:eu-repo/semantics/publishedVersio
Effective actions for modified Loop Quantum Cosmologies via order reduction
General Relativity is an extremely successful theory, at least for weak
gravitational fields, however, it breaks down at very high energies, such as in
correspondence of the initial singularity. Quantum Gravity is expected to
provide more physical insights concerning this open question. Indeed, one
alternative scenario to the Big Bang, that manages to completely avoid the
singularity, is offered by Loop Quantum Cosmology (LQC), which predicts that
the Universe undergoes a collapse to an expansion through a bounce. In this
work, we use metric gravity to reproduce the modified Friedmann
equations which have been obtained in the context of modified loop quantum
cosmologies. To achieve this, we apply an order reduction method to the
field equations, and obtain covariant effective actions that lead to a bounce,
for specific models of modified LQC, considering matter as a scalar field.Comment: 16 pages, 4 figures. V2: typo corrected in caption of Fig.4a);
references adde
Dermic diffusion and stratum corneum: a state of the art review of mathematical models
Transdermal biotechnologies are an ever increasing field of interest, due to the medical and pharmaceutical
applications that they underlie. There are several mathematical models at use that permit a more inclusive vision
of pure experimental data and even allow practical extrapolation for new dermal diffusion methodologies.
However, they grasp a complex variety of theories and assumptions that allocate their use for specific situations.
Models based on Fick's First Law found better use in contexts where scaled particle theory Models would be
extensive in time-span but the reciprocal is also true, as context of transdermal diffusion of particular active
compounds changes. This article reviews extensively the various theoretical methodologies for studying dermic
diffusion in the rate limiting dermic barrier, the stratum corneum, and systematizes its characteristics, their
proper context of application, advantages and limitations, as well as future perspectives
Limb amputation secondary to pseudoamniotic band syndrome after selective fetoscopic laser photocoagulation: case report
Pseudoamniotic band syndrome (PABS) is a rare iatrogenic complication that occurs after invasive procedures in monochorionic twins for treatment of twin-twin transfusion syndrome (TTTS). Selective fetoscopic laser photocoagulation (SFLP) is a commonly performed procedure for the treatment of severe TTTS that may lead to complications such as preterm labor, preterm rupture of membranes, cerebral lesions and fetal death. PABS has been reported to occur in up to 3% of cases of TTTS treated with laser, leading to limb abnormalities. There are no identifiable risk factors and antenatal detection of PABS is rare, but possible. Thus, obstetricians should be aware of this possibility in pregnancies treated by laser therapy for TTTS. The authors report a case of a monochorionic biamniotic twin pregnancy submitted to SFLP for TTTS at 19 weeks of gestation with postnatal diagnosis of PABS, presenting with amputation of a fetal limb.
Monitoring Vegetation Dynamics and Carbon Stock Density in Miombo Woodlands
Background
The United Nation’s Program for Reducing Emissions from Deforestation and Forest Degradation (REDD+) aims to reduce the 20% contribution to global emissions of greenhouse gases from the forest sector, offering a financial value of the carbon stored in forests as an incentive for local communities. The pre-requisite for the setup of a participatory REDD + Program is the monitoring, reporting and verification (MRV) of baseline carbon stocks and their changes over time. In this study, we investigated miombo woodland’s dynamics in terms of composition, structure and biomass over a 4-year period (2005–2009), and the Carbon Stock Density (CSD) for the year 2009. The study was conducted in the Niassa National Reserve (NNR) in northern Mozambique, which is the 14th largest protected area in the world. Results
Mean tree density distributed across 79 species increased slightly between 2005 and 2009, respectively, from 548 to 587 trees ha-1. Julbernardia globiflora (Benth.) was the most important species in this area [importance value index (IVI2005= 61 and IVI2009 = 54)]. The woodlands presented an inverted J-shaped diametric curve, with 69% of the individuals representing the young cohort. Woody biomass had a net increase of 3 Mg ha-1 with the highest growth observed in Dyplorhynchus condilocarpon (Müll.Arg.) Pichon (0.54 Mg ha-1). J. globiflora had a net decrease in biomass of 0.09 Mg ha-1. Total CSD density was estimated at ca. 67 MgC ha-1 ± 24.85 with soils (average 34.72 ± 17.93 MgC ha-1) and woody vegetation (average 29.8 MgC ha-1 ± 13.07) representing the major carbon pools. The results point to a relatively stable ecosystem, but they call for the need to refocus management activities. Conclusions
The miombo woodlands in NNR are representative of the woodlands in the eco-region in terms of vegetation structure and composition. They experienced net increase in woody biomass, a considerable recruitment level and low mortality. According to our results, NNR may present good potential for carbon sequestration especially in soils and woody biomass, representing an important potential carbon sink. However, further investigations are needed in order to address the contribution of this area to MRV REDD + initiatives
Study on the changes of soil chemical characteristics as result of prescribed fire
Every year, particularly during the summer period, the Portuguese forests are devastated by forest fire that destroys their ecosystems. So in order to prevent these forest fires, public and private authorities frequently use methods for the reduction of combustible mass as the prescribed fire and the mechanical vegetation pruning. All of these methods of prevention of forest fires alter the vegetation layer and/or soil [1-2].
This work aimed the study of the variation of some chemical characteristics of soil that suffered prescribed fire. The studied an area was located in the Serra of Cabreira (Figure 1) with 54.6 ha. Twenty sampling points were randomly selected and samples were collected with a shovel before, just after the prescribed fire, and 125 and 196 days after that event. The parameters that were studied were: pH, soil moisture, organic matter and iron, magnesium and potassium total concentration. All the analysis followed International Standard Methodologies.
This work allowed to conclude that: a) after the prescribed fire; i) the pH remained practically equal to the the initial value; ii) occurred a slight increase of the average of the organic matter contents and iron total contents; b) at the end of the sampling period compared to the initial values; i) the pH didn´t change significantly; ii) the average of the contents of organic matter decreased; and iii) the average of the total contents of Fe, Mg and K increased
Modelling Aboveground Biomass of Miombo Woodlands in Niassa Special Reserve, Northern Mozambique
Aboveground biomass (AGB) estimation plays a crucial role in forest management and carbon emission reporting, especially for developing countries wishing to address REDD+ projects. Both passive and active remote-sensing technologies can provide spatially explicit information of AGB by using a limited number of field samples, thus reducing the substantial budgetary cost of field inventories. The aim of the current study was to estimate AGB in the Niassa Special Reserve (NSR) using fusion of optical (Landsat 8/OLI and Sentinel 2A/MSI) and radar (Sentinel 1B and ALOS/PALSAR-2) data. The performance of multiple linear regression models to relate ground biomass with different combinations of sensor data was assessed using root-mean-square error (RMSE), and the Akaike and Bayesian information criteria (AIC and BIC). The mean AGB and carbon stock (CS) estimated from field data were estimated at 56 Mg ha−1 (ranging from 11 to 95 Mg ha−1) and 28 MgC ha−1, respectively. The best model estimated AGB at 63 ± 20.3 Mg ha−1 for NSR, ranging from 0.6 to 200 Mg ha−1 (r2 = 87.5%, AIC = 123, and BIC = 51.93). We obtained an RMSE % of 20.46 of the mean field estimate of 56 Mg ha−1. The estimation of AGB in this study was within the range that was reported in the existing literature for the miombo woodlands. The fusion of vegetation indices derived from Landsat/OLI and Sentinel 2A/MSI, and backscatter from ALOS/PALSAR-2 is a good predictor of AGB.info:eu-repo/semantics/publishedVersio
UV-A activation of peroxymonosulfate for the removal of micropollutants from secondary treated wastewater
The occurrence of micropollutants (MPs) in the aquatic environment poses a threat to the environment and to the human health. The application of sulfate radical-based advanced oxidation processes (SR-AOPs) to eliminate these contaminants has attracted attention in recent years. In this work, the simultaneous degradation of 20 multi-class MPs (classified into 5 main categories, namely antibiotics, beta-blockers, other pharmaceuticals, pesticides, and herbicides) was evaluated for the first time in secondary treated wastewater, by activating peroxymonosulfate (PMS) with UV-A radiation, without any pH adjustment or iron addition. The optimal PMS concentration to remove the spiked target MPs (100 mu g L-1) from wastewater was 0.1 mM, leading to an average degradation of 80% after 60 min, with most of the elimination occurring during the first 5 min. Synergies between radiation and the oxidant were demonstrated and quantified, with an average extent of synergy of 69.1%. The optimized treatment was then tested using non-spiked wastewater, in which 12 out of the 20 target contaminants were detected. Among these, 7 were degraded at some extent, varying from 10.7% (acetamiprid) to 94.4% (ofloxacin), the lower removals being attributed to the quite inferior ratio of MPs to natural organic matter. Phytotoxicity tests carried out with the wastewater before and after photo-activated PMS oxidation revealed a decrease in the toxicity and that the plants were able to grow in the presence of the treated water. Therefore, despite the low degradation rates obtained for some MPs, the treatment effectively reduces the toxicity of the matrix, making the water safer for reuse
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