bluuebunny/crossref_metadata_2025 huggingface dataset:
Investment in research and development and their impact on economic growth (GDP growth) of Bosnia and Herzegovina
Authors: Marin Slobodan , Šušić Milan
Published: February 2021

By investing in research and development, Bosnia and Herzegovina can achieve a competitive advantage in the market and play an important role in supporting research and development, because it can facilitate investments through tax policies and measures, cooperation between science, the state and companies, etc. It is important to note that all attempts to support stronger investments in research and development are fully justified, as they lead to economic growth and technological progress to Bosnia and Herzegovina. However, it is important that incentives are created in a way that not only implies investment growth, but also ensures their efficiency. More plastically, it is not only important how much will be invested in R&D, but also how, that is, what exactly will be invested in. Using theoretical models, numerous empirical studies have been conducted that examine the importance of investment in research and development and their impact on economic growth (GDP growth). Such empirical research differs in the selected variables, the type of statistical analysis and the results. The paper uses regression analysis models for selected macroeconomic indicators in the observed period. The aim of the research is to assess the effects of selected macroeconomic factors, especially the impact of investment in research and development on the growth of gross domestic product (dependent variable), and to answer the question whether investment in research and development (GERD) in Bosnia and Herzegovina is satisfactory?
Code of ethics and the ethical decision-making model as a support in teachers' professional practice
Authors: Stárek Lukáš
Published: February 2021

Educators are confronted by specific ethical issues in their everyday work. However, awareness of these issues, the search for answers to them and their consideration, demand due diligence and time. Thus, the importance of ethics and its impact may be downplayed. An educator aims to pay attention to the development of a child/student, especially with respect to the environment or social setting itself, and the responsibility toward society itself is evident from this. The educator's responsibility should also be related to the profession itself and the social perception of the teaching profession. The aim of the research was to examine whether a school's code of ethics and the training to use an Ethical Decision-making Model could be used to support teachers in solving ethical dilemmas. The research sample consisted of teaching staff working at a primary school in Prague. The teachers work in the first stage of primary school. The selected primary school has a code of ethics as an internal regulation. In total, five interviews with teachers were conducted. Respondents agreed that the Code of Ethics and Ethical Decision-making Model are good support for their professional practice. They are primarily useful in the communication process, especially when talking to children, colleagues and parents.
The modality of tandem learning as an aspect of a contemporary trend in foreign language learning: The example of the HelloTalk mobile app
Authors: Gajić Tijana , Maenza Neda
Published: February 2021

The paper highlights contemporary trends in foreign language acquisition which systematically enhance communicative abilities, contributing to the development of language skills in a creative and innovative manner. One of the leading trends is reflected in the modality of mutual learning, which is increasingly used and involves the interaction of two persons willing to teach each other their mother tongue. The paper looks at the possibilities of acquiring a foreign language using the HelloTalk mobile app, based on tandem learning and the communicative approach. The social interactions involved in problem solving through partnership enable each student to expand their zone of further development, making the topic of this paper significant in a pedagogical context. A study carried out with the aim of assessing students' attitudes to the use of this language acquisition tool is presented in the paper. Quantitative and qualitative methods were used. Data were collected using an online survey and also through focus group discussions. The findings suggest that one of the major advantages of learning a foreign language in this way is the partial or total reduction of language barriers, as well as the absence of anxiety and nervousness, which frequently accompany communication in a foreign language. The findings confirm that the HelloTalk mobile app, although appealing in language learning, is not widely used among the student population in Serbia due to students' lack of free time and their insufficient engagement, which is required in tandem learning.
Intervenções musicais no contexto hospitalar:
Authors: Mengarda Beatrís , Abich Lucas Block , Pendeza Daniele Pincolini , Da Silva Suzel Lima , Battistel Amara Lúcia Holanda Tavares
Published: February 2021

Baseado na política do HumanizaSUS, desde o ano de 2011 o Programa de Extensão Cuidado e Atenção ao Adolescente e Criança em Tratamento Oncológico (CAACTO), desenvolve atividades diversas junto à crianças e adolescentes acometidos por neoplasias. Em uma tentativa de atenuar os sofrimentos que se somam àqueles do diagnóstico e do isolamento que a vida hospitalar pode vir a causar, as intervenções musicais desenvolvidas semanalmente podem vir a ser um espaço de acolhimento e de promoção da saúde e do desenvolvimento humano. No ano de 2018, as intervenções cumpriram com seus objetivos de colaborar na humanização hospitalar e na proposição de um espaço educacional por meio da música. Essa experiência soma na formação dos alunos do Curso de Música no contexto educacional hospitalar, além de ser potente os momentos de trocas nas reuniões entre todos os integrantes do CAACTO, onde a interlocução teórico-prática para além do processo de adoecimento, permite a interdisciplinaridade na busca por melhores intervenções em benefícios de todos os envolvidos no programa.
Educação especial e teatro contemporâneo:
Authors: Lampe de Araujo Everton , Ferreira da Silva Carlos Alberto
Published: February 2021

Este texto propõe um relato do processo criativo De Lagarta a Borboleta com pessoas com deficiência na Associação de Pais e Amigos dos Excepcionais de Ouro Preto - MG. Dessa forma, o artigo visa contribuir com o campo de estudos acerca do ensino e prática do Teatro Contemporâneo em contextos de Educação Especial; além de debruçar sobre a experiência de criação colaborativa vivenciada nas práticas de teatro desenvolvidas por um grupo de estagiários do curso de licenciatura em Artes Cênicas – UFOP/MG. Por fim, busca compreender o teatro como linguagem e percurso de construção de conhecimentos vinculado a outros saberes, em contexto interdisciplinar.
De Santa à perigosa
Authors: De Oliveira Megg Rayara Gomes
Published: February 2021

Neste artigo problematizo a representação e apagamento de corpos trans femininos nas artes visuais até o final do século XIX. Procuro identificar personagens trans femininas em obras de arte que dialogam com o campo do sagrado e da mitologia, bem como em imagens produzidas por ilustradores que estavam a serviço de jornais e dos departamentos de polícia, especialmente na Inglaterra e nos Estados Unidos da América. Textos que discutem história da arte, religiosidade, mitologia, homossexualidade masculina, também foram consultados, porém adoto uma postura genealógica nos moldes propostos por Ines Dussel e Marcelo Caruso (2003). Faço uso, ainda, da perspectiva parcial proposta por Donna Haraway (1995) para analisar fragmentos da História Tradicional e da História da Arte. O conceito de interseccionalidade tem importância central neste trabalho, pois permite articular questões de classe, gênero, identidade de gênero e raça de forma simultânea. Este conceito possibilita o revezamento entre diversas áreas do conhecimento. No caso deste artigo com os estudos culturais, de gênero e diversidade sexual e com as teorias pós-estruturalistas e pós-coloniais. Para dar mais consistência às minhas reflexões, faço uso de inúmeras imagens por entender que a linguagem visual também pode ser discursiva ultrapassando os limites de leituras estéticas.
Qualidade da água para abastecimento público em municípios com menos de 50 mil habitantes na Amazônia
Authors: Malcher Jorge Angelo Simões , Brito Daímio Chaves , Carvalho Thaís Pantoja de , Santos Jéssica Oliveira dos , Penha Elaine Cristina Maciel da , Guedes Jimaine Nascimento , Cunha Alan Cavalcanti da
Published: February 2021

O abastecimento de água é um serviço essencial e imprescindível para diversas atividades humanas. Com este propósito é preciso manter a quantidade e qualidade em níveis sanitários aceitáveis. O monitoramento da qualidade da água é uma importante ferramenta para avaliar suas características físicas, químicas e microbiológicas de eminente relevância para a saúde pública. O objetivo desse estudo foi avaliar a qualidade da água de abastecimento nos munícipios de Amapá, Cutias, Itaubal, Laranjal do Jari, Mazagão e Vitória do Jari, todos pertencentes ao estado do Amapá. Foram realizadas a coleta de 94 amostras e a análise dos parâmetros cor, turbidez, condutividade elétrica, sólidos suspensos totais, oxigênio dissolvido, demanda bioquímica de oxigênio, pH, cloretos, fluoretos, nitrato, amônia, fósforo total, coliformes termotolerantes e Escherichia coli. Os resultados obtidos indicam frequente contaminação da água por coliformes termotolerantes e Escherichia coli nos sistemas de abastecimentos daquelas localidades onde há limitado nível de tratamento, com destaque aos poços rasos. Alta frequência das amostras (69,15%) apresentou não conformidade de parâmetros microbiológicos quando comparados com os padrões estabelecidos pela portaria de Consolidação nº 5, de 28 de setembro de 2017, do Ministério da Saúde. O estudo mostra a relevância do monitoramento da qualidade da água como indicador de contaminação dos mananciais utilizados para o consumo humano, ressaltando a importância de manter também seu funcionamento para o controle de qualidade em sistemas de abastecimento e distribuição.
Diagnóstico da qualidade da água do Rio Piracicaba e sua correlação com a urbanização
Authors: Batista Ana Maria Moreira , Figueiredo Tiago Antonio , Barros Adriano José de , Silva Thales Adriel Alves da , Pereira Victor Hugo Braga , Nascimento Alexandre Tulio Amaral , Araujo Giovanna Ribeiro , Siniscalchi Luciene Alves Batista
Published: February 2021

A qualidade da água no rio Piracicaba foi avaliada usando o banco de dados de 2007 a 2017 do Instituto de Gerenciamento de Água de Minas Gerais (IGAM) nas cidades de Rio Piracicaba, João Monlevade e Nova Era. O levantamento das áreas dos respectivos municípios foi realizado no sistema IDE-Sisema com um mapeamento para 2005 do IBGE e outro para 2015 do IBAMA. A qualidade da água do rio está na classe média de acordo com o cálculo do Índice de Qualidade da Água, IQA. Turbidez, Coliformes e E. coli tiveram a maior influência no sistema. As concentrações de E. coli no trecho monitorado estiveram acima do limite recomendado em 80% das amostras. O ponto RD026 foi classificado como mesotrófico e os pontos RD025 e RD029 como oligotróficos. A partir do ano de 2013 houve um incremento no total de nutrientes N e P. Os mapas gerados indicaram um aumento na área de 898,67ha em João Monlevade, 475,1ha em Rio Piracicaba e 171ha em Nova Era e o resultado foi inversamente correlacionado com a qualidade da água.
Influência da pressão e da vazão de concentrado no desempenho de ultrafiltração em pós-tratamento de esgoto
Authors: Barros Filho Marcos André Capitulino de , Andrade Neto Cícero Onofre de , Araújo André Luis Calado , Santos Hélio Rodrigues dos , Silva Layane Priscila de Azevedo , Ferreira Larissa Caroline Saraiva
Published: February 2021

Apesar das inúmeras vantagens advindas do uso da tecnologia de membranas filtrantes, algumas limitações inerentes ao processo de incrustação tornam-se relevantes para sua aplicabilidade. O controle das condições operacionais consiste em importante ferramenta para mitigar o fouling e alcançar bons níveis de eficiência. Nesse sentido, o objetivo deste trabalho foi investigar o efeito da pressão transmembrana e da vazão de concentrado no desempenho da ultrafiltração, aplicada ao pós-tratamento de esgoto sanitário. O processo foi avaliado e otimizado variando-se a pressão (0,5 e 1,5 bar) e a vazão de concentrado (300 e 600 L/h), por meio de um planejamento fatorial 22, a fim de investigar os efeitos no fluxo permeado e na qualidade dos efluentes gerados, em cada condição operacional. Avaliaram-se os seguintes indicadores de qualidade para os permeados: pH, Condutividade Elétrica, Sólidos Suspensos Totais, Turbidez, Cálcio e Demanda Química de Oxigênio (DQO).  Em todos os ensaios, observou-se diminuição acentuada do fluxo permeado nos instantes iniciais, seguida de uma queda lenta que se prolongou até atingir um patamar relativamente constante por volta dos 120 minutos de filtração. O aumento da pressão resultou em maior fluxo permeado inicial, porém com maior queda do fluxo com o tempo, evidenciando um processo de incrustação mais pronunciado. Por outro lado, o aumento da vazão de concentrado resultou em queda mais lenta de fluxo permeado com o tempo de filtração. Com relação a qualidade dos permeados, a pressão transmembrana de 0,5 bar foi a que permitiu melhores resultados, sendo confirmado estatisticamente, por meio do teste da ANOVA two-way com medidas repetidas, efeito significativo da pressão sobre a turbidez do permeado. A vazão de concentrado, por sua vez, não apresentou influência significativa sobre nenhum dos parâmetros de qualidade. Dessa forma, concluiu-se que, do ponto de vista econômico e ambiental, é mais interessante operar sistemas de membranas de ultrafiltração a uma menor vazão de concentrado associado a uma pressão transmembrana baixa, uma vez que sob estas condições haverá menor produção de rejeito e o permeado apresentará menores concentrações dos constituintes analisados, notadamente turbidez mais baixa.
A Research on Sustainability of a Geothermal Energy Resource in Kırklareli City
Authors: ÖZER Betül , KIZILAY Sinem
Published: February 2021

Geothermal energy is one of the most important renewable energy sources which provides a massive contribution to the existing region. Low-enthalpy resources are convenient, especially for direct usage applications such as household and greenhouse heating and thermal tourism with today's technology. Direct usage applications have social and economic positive effects via supplying the primary demand of the local communities, such as heating and nourishment. Although geothermal energy is clean and renewable, that causes adverse environmental impacts during drilling or usage stages. Therefore, some criteria should be taken into consideration for the sustainable evaluation of the source. These criteria can be identified within the determined framework of sustainable development goals for each project. In this study, a newly discovered geothermal energy resource at Kırklareli- Asılbeyli Region is investigated for potential applications according to the UN Sustainable Development Goals. It is pointed out the precautions should be taken into consideration from the discovery phase until the end of life for sustainable use of the source.
Human Rights of the Senior Citizens in Bangladesh: Political, Administrative and Economic Challenges
Authors: Hossain Md. Zahid , Ullah S. M. Akram , Haque A. K. M. Mahmudul
Published: February 2021

Human rights are the essential rights to all for their proper living and proper amplification of the qualities of human personality. These common rights are recognized by the Universal Declaration of Human Rights and also incorporated in the constitution of Bangladesh. But in some cases, these rights are violated in many ways. This study is an attempt to depict the causes and challenges for which the senior citizens cannot enjoy these rights properly. Its finding presents the political, administrative and economic challenges of human rights of the elderly people. Study sample of this research consisted of 60 respondents divided into three categories such as old home, general and key respondents. They were both male and female. This study has been conducted on the basis of primary and secondary sources of data collected through face to face interview and content analysis techniques. The finding revealed that a number of challenges and hostilities cumber the senior citizens in the way of their enjoying human rights with satisfaction. 48% of the senior citizens who belong to lower economic class earn their livelihood by begging. Political challenges like insufficient laws, inadequate national economy, corruption and nepotism; administrative challenges like lack of old home, lack of distinct institutions; and the poverty are responsible for this situation. This study recommends that raising moralities and consciousness, creating proper laws and their proper enforcement, establishing old homes, resistant social movement against all sorts of corruption can play an important role to prevent human rights violation of the senior citizens.
Molecular Structure and Its Inverse: The Mystery of Their Origins, the Enigma of Their Detection
Authors: Chandrasekhar Sosale
Published: February 2021

The origins of the molecular-chiral homogeneity that is the very basis of life remain a tantalizing mystery. Molecular chirality itself is manifest in its interaction with radiation, particularly as optical activity, although an intriguing alternative technique based in X-ray crystallography is being increasingly employed. Thus, X-ray diffraction with anomalous dispersion is currently believed to lead to the absolute configuration of a stereogenic center, the ultimate goal of structural chemistry. However, despite its apparently unerring consistency, the fundamental basis of the anomalous dispersion technique is itself enigmatic. This is because it is unclear how the technique not only distinguishes two enantiomeric lattices but also assigns the absolute configuration: all, apparently, in the absence of an external chiral influence! Indeed, as argued previously, it is highly likely that the technique succeeds because the X-rays employed are circularly polarized, itself a possible consequence of parity violation. All the same, the question of how the absolute configuration is assigned remains, as the chiral sense of the putative circular polarization of the X-rays is unknown. It is argued herein that the anomalous dispersion method is essentially based in the chirality of X-rays that must have entered–although unbeknownst as such–into the calculations leading to the absolute configuration. In fact, the enigma surrounding the anomalous dispersion method derives from uncertainties concerning the theory of X-ray diffraction itself, thus leading to the apparently inescapable conclusion that both methods are essentially empirical — but without detracting from the brilliance of the scientific achievements that led to these methods.
Microscopic Features, Mineral Contents, Anti-sickling, Antioxidant and Antibacterial Activities of Stem Bark of Harungana madagascariensis Lam. Ex Poiret (Hypericaceae)
Authors: Mukeba Florent Biduaya , Mukoko Johnny Bopopi , Mayangi Manix M. , Ngondo Myriam Mukadi , Ngelinkoto Patience Mpia , Bamba Jérome V. , Kitwa Fanfan , Bongo Gédéon Ngiala , Mutwale Paulin K. , Ngbolua Koto-te-Nyiwa , Ngombe Nadège K. , Mpiana Pius T. , Mbemba Théophile F. Mbemba
Published: February 2021

Aims: This study addressed the identification of bioactive compounds, the determination of mineral content and the evaluation of the antibacterial, antioxidant and anti-sickling activities of aqueous extract from stem bark of Harungana madagascariensis.

Place and Duration of Study: Centre d’Etudes des Substances Naturelles d’Origine Végétale (CESNOV), Faculty of Pharmaceutical Sciences, University of Kinshasa and Faculty of Sciences, National Pedagogic University in DRC, between October 2018 and January 2021.

Methodology: Phytochemical screening was evaluated by chromatographic methods (TLC and HPLC), the mineral composition by ICP-AES and the antioxidant activities using ABTS and DPPH assays, the antibacterial activity against four bacteria strains using the micro-dilution method; and the in vitro anti-sickling activity by the Emmel test.

Results: Phytochemical analysis revealed the abundance in this plant of phytochemicals such as alkaloids, flavonoids, tannins, anthraquinones and triterpenoids. The extract contains sodium, iron, selenium and zinc in proportions of 955.40 ppm, 369.65 ppm, 375.70 ppm and 44.79 ppm respectively as well as copper, chromium and other elements. The antioxidant potential of the stem bark infusion extract from H. madagascariensis, evaluated by the ABTS and DPPH tests, showed very high antioxidant activity due to this free radical scavenging capacity linked to IC50 values of 3.08 ± 0.19 µg/mL (ABTS) and 3.53 ± 0.22 µg/mL (DPPH). The antibacterial sensitivity testing with MIC determination performed on a strain isolated from a sickle cell patient and four reference strains showed the MIC values of the extract ranged from 31.25 µg/mL to 250 µg/mL. The lowest MIC value was observed on S. aureus ATCC 25923 while the highest MIC value was obtained on Enterococcus spp Clinical.

Conclusion: The stem bark extract of H. madagascariensis showed high anti-sickling activity at 10.42 µg/mL, which may be due to its phytochemical constituents such as saponins, alkaloids and flavonoids Obtained results could justify the efficacy of recipes from stem bark of Harungana madagascariensis in the management of various infections in traditional medicine and anti-sickle cell disease.
Drought Characterization Over Periyar Vaigai Command Area in Tamil Nadu
Authors: Sathyamoorthy N. K. , Ramaraj A. P. , Senthilraja K. , Jagannathan R. , Ramanathan S. P. , Geethalakshmi V.
Published: February 2021

India encountered numerous drought years in the decades. It is a matter of concern with increased frequency as well as intensity, mainly due to factors related to changing climate in recent years. In India livelihoods of more than 75% of the population are directly or indirectly dependent on agriculture sectors. The strong and recurrent link between drought and farmer's livelihoods has highlighted the importance to understand the drought scenario of a place for designing coping strategies. To address the issue, this paper was formulated to characterize the drought scenario over Periyar Vaigai Command (PVC) area. To summarize the results, the locations Edayapatti and Periaaruvi had the highest number of annual drought occurrence (8) while the location Madurai airport had the lowest (2) based on the analysis of 30 years. On comparing the monsoons, there are no wide variations in drought characteristics between Southwest monsoon (SWM) and Northeast monsoon (NEM). Anomalies in rainfall during the monsoon seasons were studied through SPI, consecutive drought years were well presented through SPI, which gives relevant information for crop planning. In both the monsoons, the locations Viraganur, Pulipatti and Usilampatti witness consecutive droughts. The highest of three consecutive years (1999, 2000 and 2001) were witnessed in Usilampatti during the major NEM season.
Escherichia coli in Fruit Juice Dispensers
Authors: Chesca Ana Claudia , Costa Ariana da Silva , Mangucci Carolina Bragine
Published: February 2021

Aims: The aim of this study was to evaluate the microbiological quality of juices kept in juice dispensers and sold in retail in canteens and snack bars.

Study Design: The study was done with thirty samples of juice, collected in the morning and in the afternoon, obtained at commercial establishments near Uberaba University, whereas two samples were of cashew juice, two samples of tamarind juice, two samples of passion fruit with mango juice, four samples of guava with acerola juice, eight samples of grape juice and twelve samples of passion fruit juice.

Place and Duration of Study: Food Microbiology Laboratory - University of Uberaba.

Methodology: The temperature at the time of collection was measured. A microbiological analysis was performed. The samples that were positive for thermotolerant coliforms, the analysis was continued, reaching the isolation of Escherichia coli and its subsequent serological identification.

Results: The results point to a contamination, over current legal standards, of 66.7% for the samples collected in the morning and of 73.34% for the samples collected in the afternoon. Conclusion: Greater care in good practices is suggested, especially regarding the personal hygiene of handlers, water quality, sanitation and correct temperature control of fruit juice dispensers.
Comparative Analysis of Biodiesel Production from Five Varieties of Castor Beans
Authors: Tangka Julius Kewir , Merlain Djousse Kanouo Boris , Donald Dontsa Tsafack Bertold , Croft Max , Kitio Vincent
Published: February 2021

A comparative study was conducted to estimate biodiesel productivity of five varieties of castor beans: Ricinus communis zanzibariensis {white black} (castor 1), Ricinus communis sanguineus (castor 2), Ricinus communis carmencita (castor 3), Ricinus communis zanzibariensis {dark black} (castor 4) and Ricinus communis {black Tanzania}(castor 5). The castor beans were preheated to a temperature between 22 and 33 ° C and then pressed with a manual hydraulic press, under 170 bars. The oil obtained was subjected to the transesterification reaction with methanol (99.98% pure) in a proportion of 5: 1 in the presence of sodium hydroxide as a catalyst (10,672g) for 02 hours at temperature between 60 and 70 °C. Purification was performed by reacting the methyl ester formed with heated water (55 °C) and acetic acid. The density, the kinematic viscosity at 21 ° C and the proportion of residual soap were determined later. The results for five castor varieties showed that the oil yields varied from 24 to 26.96 %; the volume of methyl ester was higher with castor 4 and lower with castor 5 but there was no significant difference in the biodiesel yields. Castor 2 has the best yield of biodiesel (93.5%), followed by castor 5 (92.5%), castor 3 (91%), castor 1 (90.75 %) and castor 4 (90%).  Therefore castor oil 2 has a better potential for biodiesel production.
Animal Production, Resource Engagement and Sustainability of Return
Authors: Ramić Edin , Salkić Besim , Salkić Ensar , Zenunović Amir , Mujić Adela
Published: February 2021

In recent years, the topic of sustainability of return has been topical. A significant number, if not the vast majority, are in fact returnees to rural areas in the wider area of ​​Bosnia and Herzegovina.  There are many objective reasons why this is so, but in this paper we will deal with the perspectives of sustainable return on the example of the region "Srednje Podrinje". Animal production imposes itself as the simplest form of production in order to engage existing resources owned by returnees, primarily land. However, one of the problems faced by the inhabitants of rural areas is the lack of knowledge about the markets for agricultural products, in connection with their chances but also threats.
Effect of the COVID-19 Pandemic on Contact Lens Wear in Greece
Authors: Chandrinos Aristeidis , Tzamouranis Dorotheos-Dimitrios
Published: February 2021

Purpose: This study demonstrates the actions that took over the contact lens (CL) wearers in Greece after the COVID-19 pandemic.

Methods: The study includes nameless web-based survey used to measure participants demographics, CL wear history, and custom wear activity of CL in a stage of noticeable risk of infection due to CL wear during the COVID-19 pandemic.

Results: During the lockdown A’ in Greece about half of the participants (42.5%) believe that the perception risk of infection using CL was extremely effective (29%) and very effective (13.5%). Only a minority (18 %) of the participants do believe that the use of CL increases the risk of COVID-19 infection. Another population (43%) do not agree with this opinion and more than a third of them (39%) resemble that are not affected by this opinion or are less informed.

Conclusion: This study presents the likelihood of reducing or ceasing the use of CLs during the COVID-19 pandemic lockdown and a relationship between the perceived risk of infection and CL use. There was also a predisposition to alter the frequency of CL wear. All eye care practitioners should give more advice to their patients that continue to wear CL and assist them to act in accordance with the new rules of handling and in favour of occasional CL wear.
Effect of electron transfer inhibitors on superoxide generation in the cytochrome bc1 site of the mitochondrial respiratory chain
Authors: Ksenzenko Marina , Konstantinov Alexander A. , Khomutov Gennady B. , Tikhonov Alexander N. , Ruuge Enno K.
Published: July 2002

Antimycin, 2‐nonyl‐4‐hydroxyquinoline N‐oxide and funiculosin induce O·−
2 generation by submitochondrial particles oxidizing succinate, whereas KCN, mucidin, myxothiazol or 2,3‐dimercaptopropanol inhibit O·−
2 generation. Thenoyltrifluoroacetone does not induce superoxide production by itself but slightly stimulates the reaction initiated by antimycin. The results indicate that auto‐oxidation of unstable ubisemiquinone formed in centre o of the Q‐cycle generates most of the O·−
2 radicals in the cytochrome bc
1‐site of the mitochondrial respiratory chain.
Regulation of yeast phosphorylase by phosphorylase kinase and cAMP‐dependent protein kinase
Authors: Wingender-Drissen Ruth , Becker Jörn Ullrich
Published: July 2002

Yeast phosphorylase is phosphorylated and activated by a cyclic AMP‐independent protein kinase (called phosphorylase kinase) and a cyclic AMP‐dependent protein kinase. Only in the presence of both kinases is phosphorylase fully activated and phosphorylated. No evidence was found for the presence of two phosphorylation sites as an identical phosphopeptide pattern of phosphorylase is obtained after phosphorylation by either one or both kinases. The kinases probably phosphorylate identical sites but recognize different subunits of phosphorylase. Phosphorylase kinase phosphorylates the high‐M
r subunit while cAMP‐dependent protein kinase phosphorylates the low‐M
r subunit.
25‐Hydroxyvitamin D3 3‐sulphate is a major circulating form of vitamin D in man
Authors: Axelson Magnus
Published: July 2002

25‐Hydroxyvitamin D3 3β‐sulphate has been identified in human plasma. The compound was isolated by anion‐exchange chromatography and following hydrolysis it was characterized by high‐performance liquid chromatography and gas chromatography‐mass spectrometry. The mean concentration of sulphated 25‐hydroxy vitamin D3 in plasma from 60 patients was 16.7 ±7.1 and the levels often exceeded those of the corresponding free compound. The study also shows that unconjugated 25‐hydroxvitamin D3 is not readily sulphated by man in vivo.
Insulin‐induced translocation of glucose transporters in rat hindlimb muscles
Authors: Klip Amira , Ramlal Toolsie , Young Douglas A. , Holloszy John O.
Published: July 2002

Insulin causes a translocation of glucose transporters from intracellular microsomes to the plasma membrane in adipocytes. To determine whether insulin has a similar effect in rat hindlimb muscles, we used glucose‐inhibitable cytochalasin B binding to estimate the number of glucose transporters in membrane fractions from insulinized and control muscles. Insulin treatment caused an approx. 2‐fold increase in cytochalasin B‐binding sites in a plasma membrane fraction and an approx. 70% decrease in cytochalasin B‐binding sites in an intracellular membrane fraction. In order to detect this effect of insulin, it was necessary to develop a procedure for isolating a plasma membrane fraction and an intracellular membrane fraction that were not contaminated with sarcoplasmic reticulum. Our results show that, as in adipocytes, insulin stimulates translocation of glucose transporters from an intracellular membrane pool to the plasma membrane in hindlimb skeletal muscles.
Hyperammonemia decreases body fat content in rat
Authors: Miñana M.D. , Felipo V. , Wallace R. , Grisolía S.
Published: July 2002

We have developed an animal model of hyperammonemia consisting of feeding rats a diet containing 20% (w/w) ammonium acetate. Ingestion of this diet markedly affects carcass composition, with a 46% reduction in lipid content. The ammonium diet alters levels of several key compounds involved in lipid metabolism. Long‐chain acylcarnitine is increased in liver by approx. 60% while free carnitine and acetylcarnitine are unaffected. The hepatic content of acetyl‐CoA increases by approx. 50%. The level of ketone bodies in blood increases by 32% but remains unchanged in liver. Our data indicate that hyperammonemia alters lipid metabolism and results in a significant decrease in body lipid content.
The three‐dimensional structure of porin from Rhodobacter capsulatus at 3 Å resolution
Authors: Weiss M.S. , Wacker T. , Weckesser J. , Weite W. , Schulz G.E.
Published: July 2002

The crystal structure of porin from Rhodobacter capsulatus strain 37b4 has been solved at 3.0 Å (1 Å = 0.1 nm) resolution by multiple isomorphous replacement and solvent‐flattening. The three pores of the trimer are well denned in the electron density map. Each pore consists of a 16‐stranded β‐barrel which traverses the membrane as a tube. Near its center the tube is narrowed by chain segments protruding from the inner wall of the barrel that form an eye‐let with an irregular cross‐section of about 6 Å by 10 Å. The eye‐let has an axial length of about 10 Å; it defines the exclusion limit for diffusing particles.
Isolation and characterization of a human cDNA clone encoding a novel DNA topoisomerase II homologue from HeLa cells
Authors: Austin Caroline A. , Fisher L.Mark
Published: July 2002

We have isolated and sequenced 3 human DNA topoisomerase II (topo II) partial cDNA clones from a HeLa carcinoma cell cDNA library. Two clones were identical to an internal fragment of HeLa topo II cDNA. The third clone, CAA5, had a different and novel sequence which shared significant nucleotide (62%) and predicted peptide (70%) homologies with a region of the HeLa topo II cDNA. Our results suggest that HeLa cells express at least two homologous forms of DNA topoisomerase II. The new HeLa topo II homologue is discussed in relation to topo II isoenzymes recently described in a Burkitt lymphoma and other cell lines.
Increased Na pump activity in the kidney cortex of the Milan hypertensive rat strain
Authors: Parenti Paolo , Villa Manuela , Hanozet Giorgio M. , Ferrandi Mara , Ferrari Patrizia
Published: July 2002

The (Na+,K+)‐ATPase activity from the kidney cortex of the Milan hypertensive rat strain (MHS) and the corresponding normotensive control (MNS) was measured both in active solubilized enzyme preparations and in isolated basolateral membrane vesicles. Kinetic analysis of the purified enzyme showed that the V
max value was significantly higher in MHS rats. The difference between MHS and MNS was not linked to a different number of sodium pumps, but was related to the molecular activity of the enzyme. Using basolateral membrane vesicles, an increased ATP‐dependent ouabain‐sensitive sodium transport was also demonstrated in MHS rats. These results support the hypothesis that a higher tubular sodium reabsorption may be involved in the pathogenesis of hypertension in this rat strain.
Identification of two subtypes in the rat type I angiotensin II receptor
Authors: Iwai Naoharu , Inagami Tadashi
Published: July 2002

A rat adrenal cDNA library was screened by colony hybridization using a rat cDNA fragment of type I angiotensin II receptor (ATIA) previously isolated from the kidney. Two cDNA clones were identified, designated as AT1B, to have a nucleotide sequence highly homologous to and yet distinct from AT1A. The amino acid sequence of AT1B consists of 359 amino acid residues and has 96% identity with AT1A. No conspicuous difference in the ligand binding characteristics was observed between AT1A and AT1B. The mRNA for AT1B was expressed in many tissues as is the case with AT1A, and most abundantly expressed in the adrenal glands in the Sprague—Dawley rats. The existence of two subtypes in the rat type I anglotensin II receptor might explain the diverse actions of angiotensin II in various tissues.
Presence and coding properties of 2′‐O‐methyl‐5‐carbamoylmethyluridine (ncm5Um) in the wobble position of the anticodon of tRNALeu (U*AA) from brewer's yeast
Authors: Glasser Anne-Lise , El Adlouni Chakib , Keith Gérard , Sochacka Elzbieta , Malkiewicz Andrzej , Santos Manuel , Tuite Mick F. , Desgrès Jean
Published: July 2002

The unknown modified nucleoside U* has been isolated by enzymatic and HPLC protocols from tRNALeu(U*AA) recently discovered in brewer's yeast. The pure U* nucleoside has been characterized by electron impact mass spectroscopy, and comparison of its chromatographic and UV‐absorption properties with those of appropriate synthetic compounds. The structure of U* was established as 2′‐O‐methyl‐5‐carbamoylmethyluridine (ncm5Um). The yeast tRNALeu (U*AA) is the only tRNA so far sequenced which has been shown to contain ncm5Um. The location of such a modified uridine at the first position of the anticodon restricts the decoding property to A of the leucine UUA codon.
Structural alignment of globins, phycocyanins and colicin A
Authors: Holm Liisa , Sander Chris
Published: July 2002

A database search employing a novel algorithm for protein structure comparison by alignment of distance matrices has revealed a striking resemblance between the tertiary structures of the bacterial toxin colicin A and globins. The globin‐like domain in colicin A contains all elements essential for the toxin's lethal ionophoric activity. The structural similarity between colicin A and globins is comparable to that between globins and phycocyanins. This suggests that these three protein families, which have unrelated sequences and different functional contexts, are an example of physical convergence to a stable folding motif, the three‐on‐three helical sandwich.
An X‐ray absorption study of the reconstitution process of bovine Cu,Zn superoxide dismutase by Cu(I)‐glutathione complex
Authors: Ascone Isabella , Longo Antonella , Dexpert Hervé , Ciriolo Maria Rosa , Rotilio Giuseppe , Desideri Alessandro
Published: July 2002

The CU(I)GSH complex has recently been shown to be a good candidate for delivering copper to the active site of Cu‐free Cu,Zn superoxide dismutase both in vivo and in vitro. In this work X‐ray absorption spectroscopy has been used to characterize the CU(I)GSH complex and to follow in vitro the reconstitution of Cu,Zn superoxide dismutase from the copper‐free protein and this complex. The results obtained indicate that the copper is directly transferred as Cu(I) from the GSH complex into the empty copper binding site. No evidence has been obtained for a ternary complex in which the metal is bound to both GSH and the protein.
Modulation of GSK‐3‐catalyzed phosphorylation of microtubule‐associated protein tau by non‐proline‐dependent protein kinases
Authors: Singh Toolsee J. , Zaidi Tanweer , Grundke-Iqbal Inge , Iqbal Khalid
Published: July 2002

The phosphorylation of bovine tau, either by GSK‐3 alone or by a combination of GSK‐3 and several non‐proline‐dependent protein kinases (non‐PDPKs), was studied. GSK‐3 alone catalyzed the incorporation of ∼ 3 mol 32P/mot tau at a relatively slow rate. Prephosphorylation of tau by A‐kinase, C‐kinase, or CK‐2 (but not by CK‐1, CaM kinase II or Gr kinase) increased both the rate and extent of a subsequent phosphorylation catalyzed by GSK‐3 by several‐fold. These results suggest that the phosphorylation of tau by PDPKs such as GSK‐3 (and possibly MAP kinase, cdk5) may be positively modulated at the substrate level by non‐PDPK‐catalyzed phosphorylations.
Identification of POMC processing products in single melanotrope cells by matrix‐assisted laser desorption/ionization mass spectrometry
Authors: van Striena F.J.C. , Jespersen S. , van der Greef J. , Jenks B.G. , Roubos E.W.
Published: July 2002

The use of matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS) in identifying proopiomelanocortin (POMC) processing products in melanotrope cells of the pituitary intermediate lobe of Xenopus laevis was explored. Mass spectra were obtained with such a high sensitivity of detection that the peptides could be identified in a single melanotrope cell. In addition to known POMC processing products of the Xenopus melanotrope cell, t he presence of previously unidentified POMC‐derived peptides was demonstrated. Together these POMC processing products accounted for the entire length of the POMC precursor. Furthermore, Xenopus possesses two genes for POMC and the sensitivity and accuracy of the MALDI‐MS technique allowed identification of processing products of both the POMCA and POMCB gene. In addition, differences were obtained between the mass spectra of melanotrope cells from Xenopus laevis adapted to different conditions of background illumination. These results show that MALDI‐MS is a valuable tool in the study of the expression of peptides in single (neuroendocrine) cells.
A mutation which disrupts the hydrophobic core of the signal peptide of bilirubin UDP‐glucuronosyltransferase, an endoplasmic reticulum membrane protein, causes Crigler‐Najjar type IIs
Authors: Seppen Jurgen , Steenken Edmee , Lindhout Dick , Bosma Piter J. , Oude Elferink Ronald P.J.
Published: July 2002

Crigler‐Najjar (CN) disease is caused by a deficiency of the hepatic enzyme, bilirubin UDP‐glucuronosyltransferase (B‐UGT). We have found two CN type II patients, who were homozygous for a leucine to arginine transition at position 15 of B‐UGT1. This mutation is expected to disrupt the hydrophobic core of the signal peptide of B‐UGT1. Wild type and mutant B‐UGT cDNAs were transfected in COS cells. Mutant and wild type mRNA were formed in equal amounts. The mutant protein was expressed with 0.5% efficiency, as compared to wild type. Mutant and wild type mRNAs were translated in vitro. Wild type transferase is processed by microsomes, no processing of the mutant protein was observed.
Calcium storage and release properties of F‐actin: evidence for the involvement of F‐actin in cellular calcium signaling
Authors: Lange Klaus , Brandt Ursula
Published: July 2002

Preceding studies have shown that the bulk of the ATP‐dependent, inositol 1,4,5‐trisphosphate (IP3)‐sensitive Ca2+ store of hamster insulinoma (HIT) cells is located in microvilli on the cell surface. Similar results were obtained with isolated rat hepatocytes. Moreover, in vesicles of microvillar origin, passive fluxes of Ca2+, ATP, and IP3 occur through cation and anion channels, respectively, suggesting that Ca2+ storage is due to ATP‐dependent Ca2+ binding to an intravesicular component. Here we demonstrate that F‐actin may be a possible candidate for this function. ATP‐actin monomers bind Ca2+ with high affinity (K
d = 2−8 nM) to their divalent cation binding sites. Polymerization of actin monomers decreases the rate constant for divalent cation exchange at this binding site by more than 3 orders of magnitude rendering bound cations nearly unavailable. F‐actin‐bound Ca2+ can be released by depolymerization and dissociation from Ca2+‐ADP‐actin monomers (K
d = 375 nM). We now provide additional evidence for the possible involvement of actin in Ca2+ storage. (1) Preincubation of surface‐derived Ca2+‐storing vesicles from HIT cells with the F‐actin stabilizer, phalloidin, strongly inhibited ATP‐dependent Ca2+ uptake, reducing the IP3‐sensitive Ca2+ pool by 70%. Phalloidin, when added after the loading process, affected neither the amount of stored Ca2+ nor IP3 action on the store. (2) F‐actin polymerized in the presence of Mg2+ in nominally Ca2+‐free buffer still contained about half of the high affinity sites occupied with Ca2+ (Mg/Ca‐F‐actin). (3) Using the fura‐2 technique, we found that in the presence of ATP, Mg/Ca‐F‐actin incorporated free Ca2+ at a relatively low rate. Short pulses of ultrasound (3–10s) strongly accelerated Ca2+ uptake, decreasing free Ca2+ from 500 nM to below 100 nM. (4) In the presence of physiological levels of Mg2+ (0.5 mM), sonication liberated large amounts of Ca2+ from Mg/Ca‐F‐actin. (5) Ca‐F‐actin released bound Ca2+ at a very slow rate. Short ultrasonic pulses rapidly elevated free Ca2+ from about 50 nM up to 500 nM. (6) Small amounts of profilin, an actin‐binding protein, released Ca2+ both from Ca‐and Mg/Ca‐F‐actin and also inhibited uptake of Ca2+ into Mg/Ca‐F‐actin. (7) Phalloidin completely inhibited Ca‐uptake into Mg/Ca‐F‐actin even during ultrasonic treatment. These findings suggest that Ca2+ storage may occur by addition of Ca‐ATP‐actin monomers to reactive ends of the polymer and emptying of this store by profilin‐stimulated release of Ca‐ADP‐actin. Thus, receptor‐operated Ca2+ signaling, initiated by phospholipase C activation, may proceed via the well‐known phosphatidylinositol phosphate‐regulated profilin/gelsolin pathway of actin reorganization/depolemerization. The importance of the proposed microvillar Ca2+ signaling system for living cells remains to be established.
Kinetic model of ATP synthase: pH dependence of the rate of ATP synthesis
Authors: Jain Siddhartha , Nath Sunil
Published: July 2002

Recently, a novel molecular mechanism of torque generation in the F0 portion of ATP synthase was proposed [Rohatgi, Saha and Nath (1998) Curr. Sci. 75, 716–718]. In this mechanism, rotation of the c‐subunit was conceived to take place in 12 discrete steps of 30° each due to the binding and unbinding of protons to/from the leading and trailing Asp‐61 residues of the c‐subunit, respectively. Based on this molecular mechanism, a kinetic scheme has been developed in this work. The scheme considers proton transport driven by a concentration gradient of protons across the proton half‐channels, and the rotation of the c‐subunit by changes in the electrical potential only. This kinetic scheme has been analyzed mathematically and an expression has been obtained to explain the pH dependence of the rate of ATP synthesis by ATP synthase under steady state operating conditions. For a single set of three enzymological kinetic parameters, this expression predicts the rates of ATP synthesis which agree well with the experimental data over a wide range of pHin and pHout. A logical consequence of our analysis is that ΔpH and Δψ are kinetically inequivalent driving forces for ATP synthesis.
Anoxia pretreatment protects soybean cells against H2O2‐induced cell death: possible involvement of peroxidases and of alternative oxidase
Authors: Amor Yehudit , Chevion Mordechai , Levine Alex
Published: July 2002

Anoxia followed by reoxygenation causes extensive damage to cellular components through generation of reactive oxygen intermediates. We examined cellular responses to oxidative stress after anoxia in cultured soybean or human fibroblast cells. Anoxia pretreatment protected soybean but not fibroblasts against H2O2 concentrations that induced programmed cell death in normoxic cells. H2O2 removal in anoxia‐pretreated soybean cultures was faster. Protection was associated with increased action of alternative oxidase (AOX) and peroxidases. AOX inhibitors abolished the protective effect, while induction of AOX protected normoxic cells against H2O2. We propose that during anoxia, plant cells can prepare for reoxygenation injury by up‐regulating their antioxidant capacity, and that AOX is involved in this process.