3,549 research outputs found
Milk and Byproducts Exports, Is It a Solution for Producers or a Problem for Consumers?
International Relations/Trade,
BRILLA: Shining on Through a Pandemic
This article highlights the community partnership between a primary school Dual Language program and university Spanish students. In this submission related to personal experience during the COVID-19 pandemic, the impact of classroom teachers within the BRILLA (Bilingual Readiness through Interaction, Language, Literacy and Alliances) program is explored. Teachers are the light bearers who make human connection and authentic learning happen in-person and over screens; pandemic, or no pandemic, they shine
The effects of education on economic growth and global competitiveness: a statistical approach
This thesis investigates whether there is a relationship between education, economic growth and global competitiveness and whether there is a relationship between South Africa’s current throughput rates in institutions of higher education, and its economic growth and global competitiveness. Economic growth is defined as a country’s ability to improve the life of its average citizen based on the strength of its economy. As such, it is increasingly important for a country to assess the factors that contribute to the improvement of their economy, which will ultimately result in its economic growth. Global competitiveness is an indication of how countries are able to provide for their people internally, as well as participate in the international market. To this end, economic growth and global competitiveness are two proxies that can be used to demonstrate the economic wellbeing of a country. Considering that prosperity under economic growth and global competitiveness of a country are driven by its people, one of the aims of this thesis was to investigate whether there is a relationship between education and economic growth and global competitiveness. Considering the recent demand in free education in South Africa, it is also important to understand whether there is a relationship between South Africa’s current throughput rates at higher education institutions and its economic growth and global competitiveness. Bearing in mind the political past which has led to inequality in the country, it is important to understand which types of education contribute to the economy and which types need to be further supported in order to increase the country’s economic productivity. Therefore, an additional aim of the thesis was to determine the relationship between South Africa’s current throughput rates in institutions of higher education, and its economic growth and global competitiveness. To address the aforementioned aims, data were collected from various open access online repositories. All the data were collated and numerous general linear models were constructed and tested to determine the different relationships as per the two aims. The results reveal that secondary school education had the highest impact on economic growth and global competitiveness on a global scale. This could be attributed to the fact that secondary school graduates tend to make up the largest part of the general workforce and as such, would make up a substantial proportion of the economy. Regarding South Africa, the only significant relationships were between green cluster universities (universities that focus on both research and technical training) and global competitiveness. Overall average throughput rates in all academic institutions were low; this could indicate that perhaps there are issues within the higher education system itself that need to be addressed in order to increase the throughput rate. From a managerial perspective, the results of this research stress the importance for the government to further investigate this area of study, as the call for free education becomes more prominent. The low throughput rates seem to suggest that the government is spending substantial amounts of money on students who do not always complete their studies. More research needs to be done to assess the root of the problem in South Africa’s tertiary education system, in order to ensure that this aspect increases its positive contribution towards the country’s economic growth and global competitiveness
The evaluation of potential dietary media, measurement parameters and storage techniques for use in forensic entomotoxicology
The term forensic entomotoxicology was coined by Pounder and is used to describe the process of using insects to determine the presence or absence of toxicants in decomposing corpses. Forensic entomotoxicology is most applicable when the orthodox sources of evidence (i.e. blood and urine) are no longer available for testing due to the degree of putrefaction as a result of the decomposition process. As the field is relatively new, various authors have conducted studies to determine the effects of different toxicants on different insects. These studies have all been conducted in the absence of a standardised protocol and we hypothesise that this has led to conflicting results (i.e. two different authors will conduct a study using the same toxicant and model insect and the effects on the insects will differ significantly). The aim of this thesis was to identify the areas which might have led to the artefacts in the results and identify ways in which to standardise them. The three areas selected were the feeding substrates and the measures taken to quantify growth rate, as well as the preservation techniques that should be used for preserving larval flies. The recommendation from the literature review was that artificial diets would be the most appropriate dietary media to use for entomotoxicological studies. An artificial diet was selected and modified for potential used in entomotoxicological studies. Four different diets (no meat treatment, fish, beef and pork artificial diets) were used to rear Chrysomya chloropyga larvae and their growth rates were measured using length and width. The fly larvae reared on the fish and no meat treatment diets did not reach pupation stage. The beef and pork diets produced the largest larvae and the flies in these treatments reached adult stage. The recommendation was that the beef and pork treatments be tested with various toxicants to establish their stability in the matrix and the diet that provides the toxicants with the most stability should be used for future entomotoxicological studies. The two other factors selected for standardisation were the parameters used to quantify growth rate, as well as the preservation techniques used to store empty Chrysomya chloropyga pupal casings and Calliphora croceipalpis third instar larvae. Previous authors have suggested that width be used as an alternative to length to quantify growth rate. The results from this thesis show that length should continue to be used as the standard parameter because the incremental change in length is much larger than the change in width, and these larger increments allow for greater resolution when estimating the age of the larvae. Various authors have also suggested that pupal casings should be stored without any preservative, whereas fly larvae should be stored in concentrations of ethanol >70%. The results in this thesis have shown that the concentration of ethanol does not make any significant difference to the proportional change of length and width of the empty pupal casings and the third instar larvae. The recommendation is that when selecting the preservation technique, the integrity of the specimen for examination of other evidence (i.e. DNA or toxicological extraction) should take precedence. Although this thesis has not completely standardised the protocol for forensic entomotoxicology, it has indicated the areas that need to be focused on in order for standardisation to occur. Future studies should focus on standardisation, as this makes studies more comparable and ultimately makes entomotoxicological evidence admissible in the court of law
Teaching of Meiosis and Mitosis in Schools of Developing Countries: How to Improve Education with a Plant Reproduction Project
Headspace versus Direct Immersion Solid Phase Microextraction in Complex Matrixes: Investigation of Analyte Behavior in Multicomponent Mixtures
This document is the Accepted Manuscript version of a Published Work that appeared in final form in Analytical Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/acs.analchem.5b01850This work aims to investigate the behavior of analytes in complex mixtures and matrixes with the use of solid-phase microextraction (SPME). Various factors that influence analyte uptake such as coating chemistry, extraction mode, the physicochemical properties of analytes, and matrix complexity were considered. At first, an aqueous system containing analytes bearing different hydrophobicities, molecular weights, and chemical functionalities was investigated by using commercially available liquid and solid porous coatings. The differences in the mass transfer mechanisms resulted in a more pronounced occurrence of coating saturation in headspace mode. Contrariwise, direct immersion extraction minimizes the occurrence of artifacts related to coating saturation and provides enhanced extraction of polar compounds. In addition, matrix-compatible PDMS-modified solid coatings, characterized by a new morphology that avoids coating fouling, were compared to their nonmodified analogues. The obtained results indicate that PDMS-modified coatings reduce artifacts associated with coating saturation, even in headspace mode. This factor, coupled to their matrix compatibility, make the use of direct SPME very practical as a quantification approach and the best choice for metabolomics studies where wide coverage is intended. To further understand the influence on analyte uptake on a system where additional interactions occur due to matrix components, ex vivo and in vivo sampling conditions were simulated using a starch matrix model, with the aim of mimicking plant-derived materials. Our results corroborate the fact that matrix handling can affect analyte/matrix equilibria, with consequent release of high concentrations of previously bound hydrophobic compounds, potentially leading to coating saturation. Direct immersion SPME limited the occurrence of the artifacts, which confirms the suitability of SPME for in vivo applications. These findings shed light into the implementation of in vivo SPME strategies in quantitative metabolomics studies of complex plant-based systems.The Natural Sciences and Engineering Research Council of Canada (NSERC)
Sigma-Aldrich Corporatio
Efeitos da prolactina na atividade monaminérgica estriatal in vivo são modulados por uma experiência reprodutiva prévia
Central prolactin (PRL) modulates neuronal activity, which is physiologically relevant and behaviorally meaningful. The stimulatory or inhibitory behavioral effects of exogenous PRL are strongly associated with dose and time of treatment. Central PRL injections produce a dual modulation of striatal dopaminergic responses in males. The activity of the striatal monoaminergic system can be modulated by a previous reproductive experience in females. The objective of the present study was to test in vivo the acute and 5 day-treatment effects of central PRL injections on the striatal dopaminergic and serotoninergic terminals activity in age-matched nulliparous and primiparous females. Seven primiparous and 6 nulliparous rats were stereotaxically implanted with guide cannulas into the lateral ventricle and into the contralateral striatum. Five daily intracerebroventricular injections of ovine prolactin (oPRL;10 mg/5 ml) were performed. On days 1 and 5, females were submitted to striatal microdialysis sessions. The concentrations of dopamine and serotonin metabolites in the dialysate were measured by HPLC-ED. Acute oPRL injection induced a decrease in extracellular levels only for HVA concentrations which was more intense in primiparous than in nulliparous dams. DOPAC concentrations were increased by PRL injection in primiparous compared to nulliparous dams on day 5. On this day DOPAC, HVA and 5HIAA primiparous baseline dialysate concentrations were significantly higher than in nulliparous animals. These data suggest that reproductive experience can modulate in vivo striatal dopaminergic responses to PRL and reveal a relation between striatal dopaminergic and serotoninergic responses that is suggestive of a similar PRL modulation of both neurotransmitter terminals.A prolactina (PRL) tem efeito modulatório sobre a atividade neuronal no sistema nervoso central, fato este relevante do ponto de vista fisiológico e comportamental. Os efeitos estimulatórios e inibitórios da PRL exógena estão fortemente relacionados com a dose e o tempo de tratamento. A injeção de PRL diretamente no sistema nervoso central pode levar a modulação da atividade dopaminérgica tanto aguda como prolongadamente, como já foi observado anteriormente em ratos. Por outro lado, esse sistema de neurotransmissão também pode ser modificado por uma experiência reprodutiva anterior em ratas. Portanto, o objetivo do presente estudo é verificar in vivo o efeito de uma única injeção de PRL ou injeções repetidas sobre a atividade dos terminais dopaminérgicos e serotoninérgicos em fêmeas nulíparas e primíparas da mesma idade. Para tanto, 7 ratas primíparas e 6 nulíparas foram submetidas a cirurgias estereotáxicas para a implantação de cânulas-guia para injeção intracerebroventricular (i.c.v.) no ventrículo lateral e para microdiálise no corpo estriado contra-lateral. Após o período de recuperação pós-cirúrgico, as ratas foram submetidas a injeções i.c.v. durante 5 dias consecutivos com PRL ovina (oPRL; 10 mg/ 5 ml). Nos dias 1 e 5, as fêmeas foram também submetidas a sessões de microdiálise que se iniciavam antes da injeção i.c.v.. As concentrações de dopamina, serotonina e seus respectivos metabólitos foram quantificadas nos dialisatos coletados a cada 20 min por meio de HPLC-ED. A injeção aguda de oPRL induziu uma diminuição nas concentrações extracelulares de HVA de maneira mais intensa em fêmeas primíparas comparadas as nulíparas. As concentrações de DOPAC estavam aumentadas no dia 5 após as injeções consecutivas de oPRL no grupo de primíparas comparadas às nulíparas. No dia 5, as concentrações basais de DOPAC, HVA e 5HIAA em primíparas foram significantemente maiores do que em nulíparas. Estes resultados são sugestivos que a experiência reprodutiva pode modular a atividade dopaminérgica estriatal in vivo em conseqüência a injeção de PRL e revelou uma relação entre a atividade dopaminérgica e serotoninérgica nesta região cerebral, o que pode ser sugestivo de que ambos os sistemas de neurotransmissão neste local podem ser modulados pela PRL
Novos requisitos técnicos para rotulagem nutricional nos alimentos embalados: overview de revisões
Introduction: Personal food preferences, purchasing decisions and eating behaviors are shaped by price, marketing, availability and accessibility, which are influenced by health policies and regulations. The National Health Surveillance Agency in Brazil (Anvisa) published in 2009 a public consultation on the proposal for a Normative Instruction that establishes the technical requirements for declaring nutrition labeling in packaged foods. However, the path through which a legislative proposal is implemented is permeated by several possibilities, being subject to disputes by interest groups, such as consumers and food companies. Objective: to carry out a comparison between the new technical requirements for declaring nutrition labeling in packaged foods with the literature on the standardization of food labels and the effects on the influence on the population’s food choices. Method: An overview of systematic reviews was conducted to carry out a comparative study between the scientific evidence and the new technical requirements for declaring nutrition labeling proposed by Anvisa. Results: Of the 99 studies identified, six systematic reviews, published from 2011 to 2018, were included. The reviews reported positive results in the presentation of nutritional information on food labels, especially when dealing with healthy choices by consumers. Based on this outcome, Anvisa’s regulation follows international labeling standards so that consumers can have more information, which favors the promotion of healthy food choices. Conclusions: The Public Consultation on nutritional labeling of foods is based on the interventions studied and on the current evidence, which ensures reliability for decision-making by the Ministry of Health and Anvisa. Introdução: As preferências alimentares pessoais, as decisões de compra e os comportamentos alimentares são moldados pelo preço, marketing, disponibilidade e acessibilidade, os quais são influenciados por políticas e regulamentações sanitárias. A Agência Nacional de Vigilância Sanitária (Anvisa) publicou em 2009 uma consulta pública da proposta de Instrução Normativa que estabelece os requisitos técnicos para declaração da rotulagem nutricional nos alimentos embalados. No entanto, o percurso pelo qual uma proposta de legislação passa a ser implementada é permeado por diversas possibilidades, estando sujeita a disputas por parte de grupos de interesse, como consumidores e empresas alimentícias. Objetivo: Realizar uma comparação entre os novos requisitos técnicos para declaração da rotulagem nutricional nos alimentos embalados com a literatura sobre a padronização de rotulagens de alimentos e os efeitos sobre a influência nas escolhas alimentares da população. Método: Foi conduzida um overview de revisões sistemáticas para realização de um estudo comparativo entre as evidências científicas e os novos requisitos técnicos para declaração da rotulagem nutricional propostos pela Anvisa. Resultados: Dos 99 estudos identificados, foram incluídas seis revisões sistemáticas, publicadas de 2011 a 2018. As revisões reportaram resultados positivos na apresentação de informações nutricionais nos rótulos dos alimentos, principalmente se tratando de escolhas saudáveis por parte dos consumidores. Baseados nesse desfecho, a regulação da Anvisa segue os padrões de rotulagem internacionais para que assim os consumidores possam ter mais informações, o que favorece a promoção de escolhas alimentares saudáveis. Conclusões: As consultas públicas sobre rotulagem nutricional de alimentos estão fundamentadas nas intervenções estudadas e nas evidências atuais, o que assegura confiabilidade para a tomada de decisão do Ministério da Saúde e da Anvisa
A construção da expressão de gênero na infância: do gesto à palavra
Este artigo aborda a construção da expressão de gênero pelas crianças, à luz das contribuições do construcionismo social. A construção da expressão de gênero, vivida por meninos e meninas, é desenvolvida na dinâmica das relações sociais. De modo continuado e ininterrupto, a construção da expressão de gênero pelas crianças se dá pelas linguagens gestuais e verbais: do gesto à palavra. Tal compreensão foi construída com base em pesquisa bibliográfica e de campo realizada com crianças de 4 a 5 anos, no ambiente escolar. Nessa investigação, os dados foram construídos por um olhar etnográfico e sistematizados mediante núcleos de significação. Nesse processo, foi possível conhecer os modos de compreensão das educadoras sobre a identificação de gênero pelas crianças bem como problematizar e compreender tais formas de entendimento. Este artigo deriva da tese de doutorado “A construção das expressões de gênero da criança no contexto da educação infantil: do corpo à palavra”
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