1,133 research outputs found

    History as Community-Based Research and the Pedagogy of Discovery: Teaching Racial Inequality, Documenting Local History, and Building Links Between Students and Communities in Mississippi and Tennessee

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    In this article we describe the process of implementing a community-based research project that linked student learning with documenting elements of local histories surrounding the civil rights movement in Mississippi and Tennessee. We show that developing a dialogue among community members, ourselves, and our students worked to democratize the research project, produce strong support among the community members, and contribute to an improved understanding of racial inequality for our students. We rely on our accounts of the process, student journals, and oral histories compiled during the research. Our findings show that there are considerable opportunities for community-based research around documenting and sharing key memories and that these can be realized even when the priorities between researchers and community members do not align. Our historically-oriented fieldwork, research, and findings serve to link service-learning to community-based research

    Development of a cosmos solid emulsion

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    Natural products are becoming a trend in the cosmetic market, due to a growing awareness and concern with the origin of these products. The certification of natural products, especially organic ones under the COSMOS signature preserves the integrity of the constituents, in an environmentally appropriate and safe for human health, expanding the concept of "green chemistry”, guaranteeing the origin, and processing of the products, storage, manufacturing, packaging, etc. The objective of this study was to develop a moisturizing cosmetic emulsion in the solid format according to COSMOS certification, with guarantee the quality of the product in a new concept of solid cosmetic. 59 tests were carried out to optimise this emulsion, with the best possible hydration level. The different tests included variations in components and their amounts, following be evaluation of sensory aspects for each formulation. The final cosmetic emulsion formulation (Figure 1) contains components of Portuguese origin such as grape seeds oil from Douro Valley, olive oil and extract of by-products of acorn (Quercus Ilex L.) and essential oils of mandarin, geranium, coriander and cinnamon. The formulation has undergone accelerated stability tests with temperatures (40 ºC /-12 ºC). The pH, density and organoleptic characteristics were evaluate. The phenolic profile of acorn by-product (Quercus ilex L.) was performe by UHPLC-DAD-ESI-MS2. A questionnaire was applying to evaluate the acceptance after use of the moisturizing cosmetic emulsion. In stability tests, overall the formulation showed small color variations and less aroma intensity, maintaining hydration and solid state. The pH changes were from 4.68 ± 0.006 to 4.78 ± 0.05 and the density was maintaining at 0.73 kg/m3 . The polar extract of acorn by-product have as major compounds trigalloyl-HHDP-glucose, valoneic acid dilactone and gallic acid, known as antioxidants compounds. The essential oils bring beneficial properties to the skin and the aroma. In the post use of solid emulsion survey applied shown that “aroma” was the second point most valorised (47.6%), after “hydration” (90.5%). The results shown that the majority of participants (81.0%) were “very satisfied” or “satisfied” with the solid emulsion indicating the intention to use it if it is on the market (76.2%). This study highlights the research in reformulations from liquid to solid products, and the potential of using Portuguese raw materials such as acorn.Thanks to FCT (Portugal) and the ERDF under the PT2020 Program for financial support to CIMO (UIDB/00690/2020) and LAQVREQUIMTE (UIDB/50006/2020). SMC acknowledges the research contract (project AgroForWealth, CENTRO-01-0145- FEDER000001).info:eu-repo/semantics/publishedVersio

    Used engine oil as alternate binder for buildings – a comparative study

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    At present, global warming and climate change are the major challenges of foremost significance that substantially influence the earth's environment. The construction sector, especially buildings, is one of the largest sources of greenhouse gas emissions. Conventional building materials such as clay bricks and cement are considered as environmentally unfriendly due to enormous emissions during their production. This paper investigates the utilisation of used engine oil (UEO) as an alternative to the usual cementitious binders. Prototypes were produced from UEO to optimise the compositions and conditions of the process and tested for compressive and flexural strength, permeability and water absorption, respectively, following the ASTM standards. Furthermore, environmental and weathering aspects were also demonstrated to ensure the feasibility of the product. Samples constituting 5% by weight UEO have shown significant results for flexural stress, compressive strength and water absorption and also passed the permeability test. Moreover, 5% of UEO samples have negligible effect in strength for accelerated weathering conditions as demonstrated by the ultraviolet test. Conclusively, UEO can be used as a replacement to conventional binding materials such as a clay bricks and cement. Sustainable development and waste management are the hallmarks of this research. </jats:p

    Effects of External Osmotic Pressure on Vesicular Secretion from Bovine Adrenal Medullary Cells

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    Secretion of catecholamines from individual vesicles of bovine adrenal medullary cells was studied with amperometry in media of various osmolarities and compared with results obtained in isotonic physiological buffer (315 mosM). Hypotonic solutions caused an increase in the number of amperometric spikes evoked by brief exposure to 5 mM Ba2+. Under moderate hypertonic conditions (630 mosM), individual vesicular events were decreased in frequency, and lower amounts were secreted per event. Furthermore, the events were temporally broadened relative to those observed during release in isotonic conditions. At 970 mosM, exposure to 5 mM Ba2+ evoked even smaller secretory events that resemble the prespike feature that has been attributed to the initial opening of the fusion pore. The lack of large spikes is not due to failure of Ba2+ entry because fura-2 fluorescence reveals an increase in intracellular divalent ions. After exposure to Ba2+ in hypertonic solution, spikes could be induced with isotonic solution transiently directed onto the cell, but this process was not accompanied by a change in the concentration of intracellular divalent ions. Thus, this procedure provides an unique opportunity to temporally separate exocytotic secretion from entry of divalent ions

    Biodegradable PEG–dendritic block copolymers: synthesis and biofunctionality assessment as vectors of siRNA

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    One important drawback of most of the currently used dendrimers for biomedical applications is their high stability under physiological conditions that can result in cytotoxicity or complications induced by the accumulation of non-degradable synthetic materials in the organism. Particularly in the gene therapy field, vector stability can further hinder the intracellular release of the nucleic acid from the dendriplex, consequently leading to low transfection efficiencies. Therefore, biodegradable cationic dendritic structures have been eagerly awaited. However, the development of these dendritic nanocarriers is challenging because of the undesired and/or premature degradation observed during their synthesis and/or application. Here, we report new hybrid-biodegradable, biocompatible, non-toxic, and water-soluble azide-terminated PEG–GATGE dendritic block copolymers, based on a gallic acid (GA) core and triethylene glycol (TG) butanoate arms, incorporating ester bonds (E) at the dendritic arms/shell. Their successful functionalization by “click” chemistry with unprotected alkynated amines allowed complexation and delivery of siRNA. The hydrophobic character of the GATGE building unit confers to these hydrolyzable dendritic bionanomaterials a great ability to complex, protect and mediate the cellular internalization of siRNA. Moreover, the localization of the degradation points at the dendritic periphery, close to the complexed siRNA, was found to be important for nucleic acid release from the nanoparticles, rendering a significant improvement of the transfection efficiency compared to their hydrolytically stable PEG–GATG copolymer counterparts. The present study puts forward these biodegradable PEG–dendritic block copolymers not only as suitable vectors for nucleic acids, but also as new avenues for further developments exploring their use in theranosticsThe authors would like to acknowledge the FEDER funds through the Programa Operacional Factores de Competitividade – COMPETE and the Portuguese funds through FCT – Fundação para a Ciência e a Tecnologia (PTDC/CTM-NAN/112428/2009 and PTDC/CTM-NAN/3547/2014) that supported this work and the FCT / MEC through National Funds and, when applicable, co-financed by the FEDER via the PT2020 Partnership Agreement under the 4293 Unit I&D. V. Leiro acknowledges the support by FCT (SFRH/BPD/69110/2010) and by the project NORTE-01-0145-FEDER-000012, financed by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). P.M.D. Moreno acknowledges the support from the Marie Curie Actions of the European Community’s Seventh Framework Program (PIEF-GA-2011-300485) and FCT fellowship (SFRH/BPD/108738/2015). This work was also financially supported by the Spanish Government (MINECO: CTQ2012-34790, CTQ2012-33436) and the Xunta de Galicia (CN2011/037)S

    Disability, violence, and mental health among Somali refugee women in a humanitarian setting

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    Background There is limited evidence on the relationship between disability, experiences of gender-based violence (GBV), and mental health among refugee women in humanitarian contexts. Methods A cross-sectional analysis was conducted of baseline data (n = 209) collected from women enrolled in a cohort study of refugee women accessing GBV response services in the Dadaab refugee camps in Kenya. Women were surveyed about GBV experiences (past 12 months, before the last 12 months, before arriving in the refugee camps), functional disability status, and mental health (anxiety, depression, post-traumatic stress), and we explored the inter-relationship of these factors. Results Among women accessing GBV response services, 44% reported a disability. A higher proportion of women with a disability (69%) reported a past-year experience of physical intimate partner violence and/or physical or sexual non-partner violence, compared to women without a disability (54%). A higher proportion of women with a disability (32%) experienced non-partner physical or sexual violence before arriving in the camp compared to women without a disability (16%). Disability was associated with higher scores for depression (1.93, 95% confidence interval (CI) 0.54–3.33), PTSD (2.26, 95% CI 0.03–4.49), and anxiety (1.54, 95% CI 0.13–2.95) after adjusting for age, length of encampment, partner status, number of children, and GBV indicators. Conclusions A large proportion of refugee women seeking GBV response services have disabilities, and refugee women with a disability are at high risk of poor mental health. This research highlights the need for mental health and disability screening within GBV response programming

    Telomeric Heterochromatin Propagation and Histone Acetylation Control Mutually Exclusive Expression of Antigenic Variation Genes in Malaria Parasites

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    SummaryMalaria parasites use antigenic variation to avoid immune clearance and increase the duration of infection in the human host. Variation at the surface of P. falciparum-infected erythrocytes is mediated by the differential control of a family of surface antigens encoded by var genes. Switching of var gene expression occurs in situ, mostly from telomere-associated loci, without detectable DNA alterations, suggesting that it is controlled by chromatin structure. We have identified chromatin modifications at telomeres that spread far into telomere-proximal regions, including var gene loci (>50 kb). One type of modification is mediated by a protein homologous to yeast Sir2 called PfSir2, which forms a chromosomal gradient of heterochromatin structure and histone hypoacetylation. Upon activation of a specific telomere-associated var gene, PfSir2 is removed from the promoter region and acetylation of histone occurs. Our data demonstrate that mutually exclusive transcription of var genes is linked to the dynamic remodeling of chromatin
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