Mantas não tecidas de nanofibras de três polímeros biodegradáveis poli(ácido láctico), PDLLA, poli(Ε-caprolactona), PCL, e poli(butileno adipato-co-tereftalato), PBAT e seus nanocompósitos com uma ...nanoargila montmorilonita (MMT) foram produzidas por eletrofiação. A morfologia, o comportamento térmico e a estrutura interna das nanofibras foram analisados por microscopia eletrônica de varredura e transmissão, calorimetria diferencial de varredura e difração de raios X, respectivamente. Observou-se que as nanofibras dos nanocompósitos possuíam diâmetros menores do que os correspondentes polímeros puros e que as nanofibras de PBAT puro e de PBAT/MMT apresentavam a menor cristalinidade de todas as mantas. A viabilidade celular de todas as nanofibras foi analisada pela técnica de redução do sal de tetrazolium pelo complexo enzimático piruvato desidrogenase presente na matriz de mitocôndrias (teste MTT). Os resultados mostraram que nenhuma manta nanofibrílica apresentou toxicidade às células e que as nanofibras de PBAT puro e seu nanocompósito propiciaram ainda um ambiente mais favorável ao desenvolvimento celular de fibroblastos de cardiomiócitos do que as condições oferecidas pelo controles, provavelmente por apresentarem menores diâmetros e baixa cristalinidade em relação às demais nanofibras. Estes resultados mostram o potencial de uso destas mantas nanofibrílicas como suportes de crescimento celular.
Non-woven mats of nanofibers of three biodegradable polymers, viz. poly(lactic acid), PDLLA, poly(Ε-caprolactone), PCL, and poly(butylene adipate-co-terephthalate), PBAT, and their nanocomposites with montmorillonite nanoclay (MMT) were produced by electrospinning. The morphology, thermal behavior and internal structure of the nanofibers were analyzed by scanning and transmission electron microscopy, differential scanning calorimetry and wide angle X-ray diffraction, respectively. The nanofibers of the nanocomposites had lower diameters than the nanofibers of the corresponding neat polymers, while the nanofibers from PBAT and PBAT/MMT were the least crystalline. The cell viability of all the nanofibers was analyzed by reduction of the tetrazolium salt by the pyruvate dehydrogenase enzymatic complex present in the mitochondria (MTT test). None of the nanofibers was toxic to the cells and the PBAT and PBAT/MMT nanofibers exhibited a more favorable environment for developing fibroblasts from cardiomyocytes than the control, probably due to their low crystallinity. These results demonstrated the potential use of nanofibers´ mats as scaffolds for cell growth.
This article describes in detail the essential stereotaxic neurosurgery to develop the electric experimental kindling model in mice. To date, available literature describing the methodology of the ...kindling model is very poor and usually neglects many relevant details about the neurosurgery, such as the manufacture of the electrodes, accurate stereotaxic coordinates of the amygdala nuclei, and the general surgery procedures (e.g., anesthesia, postsurgical recovery, fit survival of the animal's). The electric kindling model produces a progressive development of generalized tonic-clonic seizures, which can be assessed by electroencephalography and behavioral responses. The seizures displayed are produced by a repeated low-intensity electrical stimulation in specific regions of the brain that is achieved through the previous implantation of electrodes. In this study, the aim was to implant the electrodes in basolateral amygdaloid nucleus (BLA). In order to successfully establish the kindling experimental model, neurosurgery to place the electrodes is an essential step to develop the epileptogenic phenomenon. It crucial that the surgery is carried out with exceptional exactitude, because in that way the experimental model represents an accurate and valid tool to study and understand epilepsy and the results obtained can be used to develop further strategies in epilepsy clinical research.
Science has a history of excluding marginalized groups, including people who are lesbian, gay, bisexual, trans, queer, and other marginalized gender and sexual identities (LGBTQ+), and recent calls ...urge the wildlife sciences to address disparities. Literature on inclusion in the life sciences generally has focused on personal affirmation and has neglected comprehensive discussion of barriers rooted in historical, structural, and sociocultural context. In our literature review, we construct a narrative highlighting the intersections between historic LGBTQ+ exclusion in society and wildlife science due to current policy trends, pressures of cis‐heteronormativity, and survival barriers on LGBTQ+ people in wildlife sciences in the United States. Wildlife scientists must have competency on LGBTQ+ marginalization topics to advance inclusion in our discipline, and this should include comprehension of historic and current legislation and social perceptions. To bolster inclusion efforts, we recommend thoughtful data collection on experiences of LGBTQ+ people within the wildlife sciences. To address root causes of exclusion, institutions and organizations should address disparities in financial support, housing, and physical and mental health resources as part of LGBTQ+ advocacy, in addition to interpersonal efforts.
LGBTQ+ inclusion in wildlife sciences requires understanding history and ongoing systemic and social barriers. With the growth of recommendations, it's important to have perspective and consider broad‐scale need past individual actions. Through examining history, survival needs, and necessary context for wildlife research, this paper provides a launchpad for adaptive policy and targeted advocacy.
Atmospheric mercury sources are numerous and complex. Accessing and understanding the strength of each source is important for understanding mercury cycling between the various environmental ...compartments as it affects atmospheric loadings.
In this regard, this study presents an upper tropospheric near-global source evaluation of total gaseous mercury (TGM) and its impacts on atmospheric loadings are therefore examined using TGM measurements from a container aboard intercontinental passenger flights between 2005 and 2016. The trove of measurements performed on board of IAGOS-CARIBIC was exploited through developed receptor models, assuring a high likelihood of extracting the maximal amount of information from the collected data. We reconstructed atmospheric mercury concentrations and assessed the contribution of the major natural and anthropogenic sources, explaining 98% of the observations with a correlation of 82% and a significance level of 0.001 (p-value).
The results show that Asia stands out as the main hotspot of TGM, mainly loaded by factors linked to industrial and SO2-related sources. Contribution and geolocation strength of industrial, volcanic, biogenic, biomass burning, and petrogenic-related sources were quantified, identified and presented.
The improved data analysis tools as probability mass factorization methods provide additional insights into the nature of the mercury source that can then guide the development of more effective mercury-related management strategies.
Display omitted
•Gaseous mercury fluxes.•Sources apportionment of atmospheric mercury.•Upper tropospheric mercury.•IAGOS-CARIBIC project.
This paper introduces a location–allocation model to support environmental emergency response strategic planning using a drone-based network. Drones are used to verify potential emergencies, ...gathering additional information to support emergency response missions when time and resources are limited. The resulting discrete facility location–allocation model with mobile servers assumes a centralized network operated out of sight by first responders and government agents. The optimization problem seeks to find the minimal cost configuration that meets operational constraints and performance objectives. To test the practical applicability of the proposed model, a real-life case study was implemented for the municipality of Ji-Paraná, in the Brazilian Amazon, using demand data from a mobile whistle-blower application and from satellite imagery projects that monitor deforestation and fire incidents in the region. Experiments are performed to understand the model’s sensitivity to various demand scenarios and capacity restrictions.
Chronic malnutrition is a condition associated with negative impacts on physical and cognitive development. It is multi-causal and can start very early in life, already in utero, thus it is ...especially challenging to find appropriate interventions to tackle it. The government of Angola is implementing a standard of care program with potential to prevent it, and the provision of cash transfers and the supplementation with small quantity lipid-based nutrients (SQ-LNS) are also promising interventions. We aimed to evaluate the impact of the standard of care program alone and of the standard of care plus a cash transfer intervention in the lineal growth of children less than 2 years old and compare it to the effectiveness of a nutrition supplementation plus standard of care program in Southern Angola.
The three-arm parallel cluster randomised controlled trial is set in four communes of Huila and Cunene provinces. Clusters are villages or neighbourhoods with a population around 1075 people. A total of twelve clusters were selected per arm and forty pregnant women are expected to be recruited in each cluster. Pregnant women receive the standard of care alone, or the standard of care plus unconditional cash transfer or plus nutritional supplementation during the first 1000 days, from pregnancy to the child reaching 24 months. The primary outcome is the prevalence of stunting measured as height-for-age Z-score (HAZ) < -2 in children below 2 years. Impact will be assessed at 3, 6, 12, 18 and 24 months of children's age. Secondary outcomes include mortality, morbidity, caring, hygiene and nutrition behaviours and practices, and women and children's dietary diversity. Quantitative data are also collected on women's empowerment, household food security, expenditure and relevant clinical and social events at baseline, endline and intermediate time points.
The results will provide valuable information on the impact of the standard of care intervention alone as well as combined with an unconditional cash transfer intervention compared to a nutrition supplementation plus standard of care intervention, carried out during the first 1000 days, in the children´s growth up to 2 years and related outcomes in Southern Angola.
Clinical Trials NCT05571280. Registered 7 October 2022.
Central Chile is undergoing its most severe drought since 2010, affecting ecosystems, water supply, agriculture, and industrial uses. The government's short-term measures, such as increasing ...groundwater extraction (by 383 % from 1997 to 2022), are exacerbating the situation, leading to long-term hydrological deterioration. The objective of this research is to establish the main processes driving the water table depth evolution within Central Chile over the period 1979–2023. This is done by conducting groundwater balances on five major hydrological basins of Central Chile. For the Megadrought (MD) period (2010−2022), the groundwater level depths reflect not only the recharge variability but, especially, the forcing trend of groundwater withdrawals: they represent 35 % and 65 %, respectively, of the total phreatic level drawdown. This result underlines the dominant role played by groundwater withdrawals in the current delicate state of Central Chile's groundwater resources, while revealing that drought is a new complex phenomenon to deal with, in the midterm, to revert the current water resource trend in Central Chile. Our study moreover presents the impact of climate change in the basin in the framework of six different groundwater withdrawal scenarios. In the worst case (i.e., RCP8.5), the aquifer recharge decreases 18 % with respect to 1979–1997, which is the period assumed to be unaffected by the impact of MD and withdrawals. Such a reduction may be irrelevant in the dynamics of the aquifer system if the current extraction rate does not change. The estimated recovery time needed to reach aquifer conditions equal to those of the unaffected period is approximately 50 years.
Display omitted
•The aquifer system of Central Chile is experiencing a long anthropogenic drought.•Groundwater declining trend in Central Chile is driven by overpumping since 90's.•Megadrough (MD) impact is not enough to drive the observed the aquifer depletion.•Climate change impact not relevant if compared with that of current overpumping.•Aquifer recovery time to conditions previous to MD is 50 years in the best scenario.
PDF
