bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrasonic Surface Machining of Aluminium Alloy Parts
Authors: Samul Artyom , Gileta Viktor , Nasonov Alexander , Kudryavtseva Yulia , Samul Ilya
Published: February 2022

The paper is devoted to the formation of established microgeometry and physical and mechanical performance of the surface layer (SL) of aluminium alloy parts (D16 and D16T GOST 4784-2019, DIN equivalent is 3.1355 or AlCuMg1 for ISO), by ultrasonic surface machining (USM). It is found that for the materials under study it is more proficient to use the USM scheme with applying vibrations of a tool along a tangent to the surface to be treated. The influence of static load and machining speed on height roughness parameters and microhardness of the surface layer is revealed. USM with the tangential scheme of vibration applying forms a specific regular microgeometry on the surface of the parts. This microgeometry differs from other ones obtained by methods of surface machining based on plastic deformation, including diamond burnishing.
Prospects for Improving Physical and Mechanical Properties of Corundum Ceramics
Authors: Komolikov Yuri , Pudov Vladimir
Published: February 2022

The prospects for improving microhardness and strength characteristics of corundum ceramics (Al2O3) modified by zirconium dioxide (3YSZ) are investigated. Ceramic samples are molded by semi-dry pressing followed by sintering. It is experimentally established that an increase in 3YSZ content in Al2O3/3YSZ composite ceramics fired at temperatures above 1450 oC increases strength and decreases microhardness. Ceramics of optimal composition (100–x) Al2O3–x 3YSZ, x = 5–10 wt. % 3YSZ has high strength and hardness values, and the average value is 700MPa and 22.3±1.8 GPa.
Influence of Curved Fibers on the Mechanical Behavior of Variable Stiffness Composites
Authors: Malakhov Andrei V.
Published: February 2022

Composite materials are widely used in various industries due to their high specific characteristics. The most common composites are laminates, which consist of multidirectional layers with unidirectional fibers adapted to stresses of the laminates. However, the efficiency of such structures is significantly reduced when there are stress concentrators. One of the ways to increase the efficiency of composite structures with stress concentrators is to change the reinforcement structure and use the transition from unidirectional fibers to curvilinear fibers, which could be adapted to both the geometry and the loads of the composite structures. This short review describes the various methods by which it is possible to manufacture composite structures with curved fibers and change the reinforcement structure. Composite structures both unidirectional fibers and curved fibers made by different manufacturing technologies are considered and compared as well as the efficiency of the composites is analyzed.
Dental fluorosis and associated risk factors among secondary school students in Zing community, North-Eastern Nigeria
Authors: Ofiri Ewere Patience , Inegbenosun Hope
Published: February 2022

Fluorosis affects both children’s oral health and quality of life because even the mildest form of tooth discoloration is considered cosmetically unacceptable and is a cause of psychological concern for those affected. This study aims to assess the prevalence of dental fluorosis and determine its associated risk factors among adolescents in the Zing community. This study is a quantitative crosssectional survey. The study participants were 300 children residing in Zing community and studying in one of the secondary schools selected for this study using a systematic random sampling technique. A questionnaire was designed and pretested to record information about demographic characteristics and risk factors for dental fluorosis. The children were also asked about their source of water consumption and their main source of drinking water recorded. The Dean Fluorosis Index (1934) was used to determine the grade of the severity of dental fluorosis. A Chi-square analysis test was used to test for possible associations. The prevalence of dental fluorosis was calculated as 52.0% and it varied significantly with age. A severe form of dental fluorosis (21.7%) was the most common grade of severity of dental fluorosis. Mild dental fluorosis had the lowest prevalence of 6.0%. The correlation between the occurrence of dental fluorosis and the duration of residence was found to be highly statistically significant (p≤0.001). The prevalence of dental caries in this study was 12.7%. No correlation was found between dental fluorosis and caries status. The prevalence of dental fluorosis was significantly high among the secondary school students of the Zing community in Taraba State. There is thus a need for health education and community awareness for preventing fluorosis and for early intervention to reduce the consequences on dental and periodontal health status.
Transient Ischemic Attacks as the First Presentation of JAK2-V617F Positive Chronic Myeloproliferative Neoplasm
Authors: Kalala Fani , Mamara Antigoni , Ioannou Maria , Speletas Matthaios
Published: February 2022

Several studies have shown that thrombotic events may underlie a latent or subclinical myeloproliferative neoplasm (MPN) and precede its definite diagnosis by 1–2 years. An early diagnosis of patients with MPN, especially those with thrombotic events in the latent MPN phase, would be beneficial for their management, preventing further morbidity and improving their quality of life. For the majority of these cases, the location of thrombosis is mainly in the splanchnic major veins, while ischemic stroke and cerebral venous thrombosis are rarely observed. In this report, we present a female patient with transient ischemic attacks who suffered from a latent MPN, on the basis of a positive testing for the JAK2-V617F mutation.
Thrombotic Microangiopathy Associated with Bortezomib Treatment in a Patient with Relapsed Multiple Myeloma
Authors: Salmenniemi Urpu , Remes Kari
Published: February 2022

Thrombotic thrombocytopenic purpura (TTP) and hemolytic-uremic syndrome (HUS) describe microvascular occlusive disorders characterized by thrombocytopenia due to increased platelet aggregation and fragmentation hemolysis. We report here what to our knowledge is the second case of TTP/HUS associated with bortezomib treatment.
FLT3/ITD Associated with an Immature Immunophenotype in PML-RARα Leukemia
Authors: Takenokuchi Mariko , Kawano Seiji , Nakamachi Yuji , Sakota Yasuyuki , Syampurnawati Meilani , Saigo Katsuyasu , Tatsumi Eiji , Kumagai Shunichi
Published: February 2022

Acute promyelocytic leukemia (APL) is characterized by the specific PML-RARa fusion gene resulting from translocation t(15;17) (q22;q12). Internal tandem duplication (ITD) of the FLT3 gene has been observed in approximately 35% of APLs, and large-scale studies have identified the presence of ITD as an adverse prognostic factor for acute myeloblastic leukemia (AML) patients. Aberrant expressions of surface antigens, such as CD2, CD34, and CD56, have been found in APL, but the implications of this are not well understood. We investigated the incidence of the FLT3/ITD mutation and FLT3/D835 (I836) point mutation in 25 APL patients. Incidence ratios of FLT3/ITD, D835 (I836), and both FLT3/ITD and D835 (I836) were 36%, 36% and 8%, respectively. FLT3/ITD+ cases showed a predominance of the bcr3 isoform (P = 0.008) and M3v morphology (P < 0.001). We found that all FLT3/ITD+ cases expressed CD2 (9 of 9) more frequently than that of FLT3/ITD− (1 of 16) (P < 0.001), while only one of the CD2+ cases (1 of 10, 10%) did not harbor FLT3/ITD, and all CD2+CD34+ cases (5 of 5, 100%) harbored FLT3/ITD. In addition, quantitative polymerase chain reaction analysis showed that FLT3 mRNA was more abundantly expressed in FLT3/ITD+ than that in FLT3/ITD− (P = 0.025), while there was no difference between D835(I836)+ and D835(I836)− with regards to aberrant surface-antigen expression, expression levels of FLT3 mRNA, M3v morphology, and the bcr3 isoform of PML-RARa mRNA. This study demonstrates that the presence of FLT3/ITD, but not D835 (I836), is closely related to aberrant CD2 expression and high expression levels of FLT3 mRNA. Our findings also suggest that FLT3/ITD as a secondary genetic event may block differentiation at the immature stage of APL.
Discoidin domain receptor 1 as a promising biomarker for high-grade gliomas
Authors: Erdem Dilek , Gunaldi Meral , Karaman Irem , Adilay Utku , Yılmaz İlhan Umit , Eseoglu Metehan , Avcıkurt Ayla , Isıksacan Nilgun , Erdogan Uzay , Gunaldi Omur
Published: February 2022

Background:

Two fundamental challenges in the current therapeutic approach for central nervous system tumors are the tumor heterogeneity and the absence of specific treatments and biomarkers that selectively target the tumor tissue. Therefore, we aimed to investigate the potential relationship between discoidin domain receptor 1 (DDR1) expression and the prognosis and characteristics of glioma patients.

Materials and Methods:

Tissue and serum samples from 34 brain tumor patients were evaluated for DDR1 messenger ribonucleic acid levels in comparison to 10 samples from the control group, and Kaplan–Meier survival analysis has performed.

Results:

DDR1 expression was observed in both tissue and serum samples of the patient and control groups. DDR1 expression levels in tissue and serum samples from patients were higher in comparison to the control group, although not statistically significant (P > 0.05). A significant correlation between tumor size and DDR1 serum measurements at the level of 0.370 was reported (r = 0.370; P = 0.034). The levels of DDR1 in serum showed a positive correlation with the increasing size of tumor. The results of the 5-year survival analysis depending on the DDR1 tissue levels showed a significantly higher survival rate (P = 0.041) for patients who have DDR1 tissue levels above cutoff value.

Conclusions:

DDR1 expression was significantly higher among brain tumor tissues and serum samples and its levels showed a positive correlation with the increased size of tumor. This study can be a starting point, since it investigated and indicated, for the first time, that DDR1 can be a novel therapeutic and prognostic target for aggressive high-grade gliomas.
Multi-institutional dose audit in radiotherapy facilities using in-house developed optically stimulated luminescence disc dosimeters
Authors: Kumar Pradip , Sharma Sunil Dutt , Dhabekar Bhushan , Rawat Narender Singh , Mishra Devesh Ramdhar , Chaudhari Suresh , Chandola Rakesh Mohan , Routh Tapan , Agrawal Sadhana
Published: February 2022

Aim:

The aim of this study was to carried out the audit of radiotherapy centers practicing conformal radiotherapy techniques and demonstrate the suitability of this indigenous optically stimulated luminescence (OSL) disc dosimeters in beam quality audit and verification of patient-specific dosimetry in conventional and conformal treatments in radiotherapy.

Materials and Methods:

Dose audit in conventional and conformal (intensity-modulated radiotherapy and volumetric-modulated arc therapy) radiotherapy techniques was conducted using in-house developed Al2O3:C-based OSL disc dosimeter and commercially available Gafchromic EBT3 film in 6 MV (flat and unflat) photon and 6 and 15 MeV electron beams. OSL disc dosimeter and Gafchromic EBT3 film measured dose values were verified using the ionization chamber measurements.

Results:

Percentage variations of doses measured by OSL disc dosimeters and EBT3 Gafchromic film for conventional radiotherapy technique were in the range of 0.15%–4.6% and 0.40%–5.45%, respectively, with respect to the treatment planning system calculated dose values. For conformal radiotherapy techniques, the percentage variations of OSL disc and EBT3 film measured doses were in the range of 0.1%–4.9% and 0.3%–5.0%, respectively.

Conclusion:

The results of this study supported by statistical evidence provided the confidence that indigenously developed Al2O3:C-based OSL disc dosimeters are suitable for dose audit in conventional and advanced radiotherapy techniques.
Programmed Death Ligand 1 Expression in Lung Adenocarcinoma: An Analysis of the Histomorphological Features
Authors: Shukla Saumya , Anand Nidhi , Pandey Rahul Kumar , Hadi Rahat , Husain Nuzhat
Published: February 2022

Background:

Immunotherapy is now a vital target therapy in the advanced cases of lung adenocarcinoma. The outstanding result of therapies with medications that inhibit the interaction of programmed death ligand 1 with programmed death protein 1 has revolutionarized prognostic treatment regimes.

Aims:

The study was undertaken with the objectives to analyze the detailed histomorphological features of adenocarcinoma lung with programmed death ligand-1 (PD-L1) expression in tumor cells and to compare the histomorphological features with PD-L1 negative group.

Materials and Methods:

The present study is a retrospective case series with 100 cases of non-small cell lung cancer-adenocarcinoma phenotype in which testing for PD-L1 had been done using immunohistochemistry. Detailed histomorphological analysis and comparison was performed for both the PD-L1 positive and negative phenotype.

Results:

Histomorphological features of 25 cases with positive PD-L1 positivity in the tumor cells and 75 cases that were negative for PD-L1 were analyzed. The most frequent pattern in the category that was PD-L1 positive was singly scattered cells or loose clusters present in 84% cases followed by solid nests that was identified in 60% cases. The presence of solid nests in the PD-L1 positive category was statistically significant (P = 0.018). Mucin was identified in 24% cases, and tumor necrosis was documented in 60% cases with PD-L1 positivity. In the cluster that was PD-L1 positive, 92% cases had moderate-to-severe nuclear pleomorphism.

Conclusion:

The identification of histomorphological patterns and characteristics may aid in triaging cases that have the likelihood to harbor PD-L1-positive phenotype, which has predictive and prognostic outcome.
On the roots of polynomials with log-convex coefficients
Authors: Hernández Cifre María A. , Tárraga Miriam , Yepes Nicolás Jesús
Published: February 2022

In this paper, we consider the family of nth degree polynomials whose coefficients form a log-convex sequence (up to binomial weights), and investigate their roots. We study, among others, the structure of the set of roots of such polynomials, showing that it is a closed convex cone in the upper half-plane, which covers its interior when n tends to infinity, and giving its precise description for every
$n\in \mathbb {N}$
,
$n\geq 2$
. Dual Steiner polynomials of star bodies are a particular case of them, and so we derive, as a consequence, further properties for their roots.
FATORES INFLUENCIADORES DO RECONHECIMENTO DE ATIVOS FISCAIS DIFERIDOS EM EMPRESAS DO IBOVESPA
Authors: Schuh Clari , Ribeiro Silvio Paula , Simon Davi Souza , Kronbauer Clóvis Antônio
Published: February 2022

O reconhecimento dos Ativos Fiscais Diferidos (AFD) é normatizado pela Deliberação da CVM de n. 599/09, no entanto, existe margem dentro desses critérios para um maior ou menor nível de reconhecimento destes ativos, influenciando no lucro e composição do patrimônio das empresas. O estudo objetivou descrever os fatores influenciadores do reconhecimento de ativos fiscais diferidos (AFD) em empresas do Ibovespa. A pesquisa foi descritiva, com análise documental e abordagem quantitativa. A amostra foi composta por 59 empresas brasileiras do Ibovespa, a análise compreendeu o período de 2009 a 2017 e os dados foram obtidos no site da B3. Por meio de um exame de conteúdo e regressão de dados em painel, os resultados indicam que a variável endividamento não apresentou relação significativa com o Índice de AFD na amostra da pesquisa, divergindo do resultado da maioria dos estudos anteriores. A variável rentabilidade financeira apontou uma relação negativa e significativa na maior parte das especificações com o Índice de AFD. As variáveis T1(logaritmo natural da receita de vendas) e T2 (logaritmo natural do valo do ativo total) reportam relação significativa e negativa com o nível de IAFD. Este resultado pode estar relacionado com a mudança institucional (IFRS), sugerindo a necessidade de pesquisas futuras que permitam a identificação de explicações e fatores relacionados de forma concreta ao nível de AFD das empresas brasileiras.
CICLO DE VIDA DAS COMPANHIAS ABERTAS BRASILEIRAS COMO DETERMINANTE DE SUA ESTRUTURA DE CAPITAL
Authors: Victor Fernanda Gomes , Carpio Graciela Beatriz , Vendruscolo Maria Ivanice
Published: February 2022

Este estudo tem por objetivo analisar a relação entre estrutura de capital e ciclo de vida empresarial, fundamentado no modelo proposto por Dickinson (2011), que diferencia as fases do ciclo de vida com base no comportamento dos fluxos de caixa. Desse modo, foi realizada uma pesquisa quantitativa, descritiva quanto aos objetivos, documental utilizando demonstrações financeiras do período de 2008 a 2015, disponíveis no banco de dados da Economática®. A amostra, não probabilística intencional, é formada por 210 companhias com ações negociadas na B3. Para responder ao problema de pesquisa foram utilizados testes de diferença de médias (ANOVA) e análise de regressão múltipla com dados em painel não balanceados, tendo por variável dependente o nível de endividamento e, por variável de interesse, a classificação do ciclo de vida. Os resultados indicam um padrão de comportamento de maior endividamento das empresas em fases iniciais (Introdutória e Crescimento) de seu ciclo de vida. As análises de regressão múltipla corroboram esse achado para as empresas jovens, e também trazem indícios de que, na medida em que a empresa se situa em etapas mais avançadas de seu ciclo de vida, há uma tendência de diminuição da dívida em sua estrutura de capital. Conclui-se que as informações oriundas da Demonstração dos Fluxos de Caixa são úteis para supor a estrutura de capital da empresa, evidenciando um comportamento de maior endividamento em empresas jovens e menor endividamento em empresas mais maduras.
INCERTEZA E INVESTIMENTO: UMA ABORDAGEM SOB A ÓTICA DA TEORIA DAS OPÇÕES REAIS
Authors: Da Silva Polyandra Zampiere Pessoa , Machado Márcio André Veras
Published: February 2022

Este trabalho teve por objetivo analisar o efeito da incerteza sobre o nível de investimento das empresas do mercado brasileiro. A amostra foi composta por todas as empresas não financeiras listadasx1x na B3 entre o período de 2008 a 2014. Como proxy para a incerteza total, utilizou-se a volatilidade histórica do retorno das ações. Decompôs-se essa medida em três componentes de risco: o de mercado, o idiossincrático e o específico da firma. Além disso, utilizou-se uma proxy alternativa para medição da incerteza, a volatilidade condicional do retorno das ações. Para análise do efeito da incerteza sobre as decisões de investimento, utilizou-se o método de Mínimos Quadrados Ordinários (MQO) e Mínimos Quadrados em Dois Estágios (MQ2E). Os resultados indicam que a incerteza total tem um efeito negativo sobre o nível de investimento, conforme esperado. Quanto às incertezas de mercado e idiossincrática, verificou-se que não há um efeito estatisticamente significativo sobre o nível de investimento, enquanto que a incerteza específica tem um efeito negativo e significativo, inclusive superior em magnitude ao da incerteza total. Ademais, identificou-se que, para o mercado brasileiro: i) as empresas com restrição financeira e as mais competitivas são mais sensíveis às proxies de incerteza; ii) que os resultados são robustos para o período de full IFRS; e iii) que não houve alteração significativa nos resultados encontrados ao utilizar uma medida alternativa para a variável incerteza. Portanto, pode-se concluir que a incerteza tem um efeito negativo sobre o nível de investimento, com destaque para a incerteza específica da firma, que possui um efeito superior, quando comparado às demais incertezas. Sendo assim, o estudo espera contribuir trazendo o debate do uso de modelos alternativos para análise de investimento que considerem a incerteza e a flexibilibilidade gerencial do ambiente de negócios, fatores que são relevantes para avaliação de projetos.
SUSTENTABILIDADE DA DÍVIDA PÚBLICA: UMA ANÁLISE DE CURTO E LONGO PRAZO APLICADA AOS MUNICÍPIOS AGREGADOS
Authors: Cardoso Vanessa Rodrigues dos Santos , Pansani Daniel Azevedo , Serrano André Luiz Marques , Wilbert Marcelo Driemeyer
Published: February 2022

A recente piora das condições macroeconômicas do país, com reflexos no agravamento das finanças públicas nos três níveis de governo trazem à tona preocupações com a sustentabilidade da dívida pública. As diversas repactuações da dívida municipal realizadas desde 1987, bem como a promulgação da Lei de Responsabilidade Fiscal (LRF), que limitou despesas e endividamento, com vistas a estabelecer maior governança à Administração Pública, são exemplos de esforços do Governo Federal para conter a deterioração da situação fiscal dos entes subnacionais. Nesse sentido, espera-se que as dívidas contraídas por estes entes sejam sustentáveis. Dessa forma, este estudo objetiva identificar a existência de condição de sustentabilidade da dívida pública municipal agregada com base em testes de estacionariedade e cointegração da dívida com o resultado primário, assim como pela reação desse último às variações daquela. A verificação mês a mês, compreendendo o período de 2002 a 2018, foi realizada por meio do teste proposto por Pasinetti (1998). Os resultados econométricos indicaram sustentabilidade para o período completo de 2002 a 2015. Entretanto, o teste de Pasinetti apontou persistência de insustentabilidade por quarenta e seis meses consecutivos iniciados em fevereiro de 2015 até novembro de 2018, havendo relação com a recessão econômica. Os achados indicam que as medidas de socorro implementadas pelo Governo Federal e a austeridade pretendida pela LRF não foram suficientes para manter a dívida pública dos municípios em patamar considerado sustentável nos períodos recentes.
A INFLUÊNCIA DE FATORES INSTITUCIONAIS SOBRE A DIVULGAÇÃO DE INFORMAÇÕES SOCIOAMBIENTAIS NA AMÉRICA LATINA
Authors: Lima Sérgio Henrique de Oliveira , Freitas George Alberto de , Oliveira Marcelle Colares , Leocádio Áurio Lúcio
Published: February 2022

A despeito do crescente volume de pesquisas sobre o desempenho socioambiental corporativo e sua evidenciação, poucos estudos se dedicaram a comparar países latino-americanos, considerando fatores institucionais relativos ao contexto do país e às empresas que neles atuam. Neste contexto, o estudo teve como principal objetivo investigar os determinantes institucionais da divulgação de informações socioambientais de companhias das seis maiores economias da América Latina, a saber, Brasil, México, Argentina, Colômbia, Chile e Peru. Os pressupostos da abordagem do Sistema Nacional de Negócios (SNN) foram tomados de suporte teórico para propor as hipóteses de pesquisa. Os resultados, obtidos junto a uma amostra de 587 empresas presentes no relatório Reports List 2015 da Global Reporting Initiative, evidenciaram (i) a existência de níveis mais elevados de divulgação pelas empresas que atuam no Peru, no Chile e na Argentina, (ii) a influência negativa dos níveis de liberdade econômica, desenvolvimento humano e rigor na aplicação de regulação ambiental, e (iii) a influência positiva do ambiente de governança, do nível de corrupção e da listagem em índices de sustentabilidade sobre a divulgação socioambiental. O estudo contribui para suplantar uma lacuna na literatura empírica ao relacionar fatores institucionais no nível de país e no nível da firma com foco na América Latina. Discutem-se ainda algumas limitações do estudo e oportunidades de futuras pesquisas no campo.
AS LÓGICAS INSTITUCIONAIS INCORPORADAS AO BALANCED SCORECARD (BSC): UM MODELO PARA ESTUDAR A ADAPTAÇÃO DO BSC
Authors: Wanderley Cláudio De Araújo , Souza Gustavo Henrique Costa
Published: February 2022

Este artigo examina a adaptação das práticas gerenciais, em nível intraorganizacional, com foco no Balanced Scorecard. O objetivo desse estudo é propor um modelo conceitual para o estudo da adaptação do BSC em nível intraorganizacional com base na literatura da lógica institucional e no modelo proposto por Ansari et al. (2010) – de que os padrões específicos de adaptação de práticas dependerão do ajuste entre a prática em difusão e a organização adotante. Neste artigo, sugere-se que a adaptação de práticas de contabilidade gerencial numa organização pode ser determinada pelo ajuste entre a lógica institucional dominante incorporada na empresa e a lógica institucional embutida na prática em difusão. Com base nesta proposição, foi desenvolvido um modelo conceitual para estudar a adaptação do BSC em nível intraorganizacional. Como resultado, oferece-se este modelo conceitual como uma forma analítica de usar o conceito de lógica institucional para explicar o processo de adaptação do BSC em uma organização.
INVESTIMENTOS PÚBLICOS E FATORES POLÍTICOS NOS PEQUENOS MUNICÍPIOS BRASILEIROS: O QUE É RELEVANTE?
Authors: Gerigk Willson , Ribeiro Flávio
Published: February 2022

A presente pesquisa estudou os municípios brasileiros com menos de cinco mil habitantes. O objetivo foi analisar a influência de variáveis políticas sobre os gastos com investimentos públicos realizados pelos municípios brasileiros com menos de cinco mil habitantes.As análises foram realizadas empregando-se a técnica de dados em painel pelo método de efeitos fixos. As variáveis explicativas referem-se aos seguintes fatores políticos: (i) ciclo político orçamentário; (ii) ideologia partidária; (iii) alinhamento político entre os pequenos municípios e os níveis superiores de governo; e (iv) competição política. A análise englobou os anos de 2001 a 2012 e a amostra inicial englobou 11.778 observações. Os resultados indicaram que os investimentos públicos foram influenciados pelos ciclos políticos orçamentários, tanto nas eleições estaduais/federais como nas municipais, entretanto, apresentaram maior aplicação de valores em anos de pleitos estaduais/federais. A ideologia partidária revelou que, para o conjunto de todos os pequenos municípios, os partidos de centro e de direita aplicaram mais recursos em investimentos públicos que os partidos ideologicamente de esquerda. Entre as regiões, esse fato somente foi registrado no Sul. O alinhamento político, por meio de coligações indiretas, entre os pequenos governos locais e o governo federal e os estaduais, foi a forma de relação política que mais impactou os investimentos nos pequenos entes locais. Por fim, os investimentos públicos, nos municípios brasileiros com população inferior a cinco mil habitantes, não se mostraram suscetíveis à competição política.
Distribution spatio-saisonnière des micro-algues de la retenue d’eau d’Adzopé (Côte d’Ivoire)
Authors: Kouassi Blé Alexis Tardy , Komoe Koffi , Egnankou Wadja Mathieu
Published: February 2022

La dynamique spatio-saisonnière des micro-algues de réservoir d’Adzopé a été analysée à partir d’échantillons collectés mensuellement de janvier à décembre 2005. Un total de 186 taxons de rang spécifique et infra spécifique a été identifié. Au niveau spatial, les densités les plus élevées sont enregistrées en aval alors que les densités les plus faibles le sont en amont. Au niveau saisonnier, en général, les densités micro-algales sont maximales lors de la grande saison sèche et de la petite saison pluvieuse en relation avec les fortes concentrations en nitrates et orthophosphates. Lors de ces périodes, des taxons comme Geitleribactron periphyticum, Microcystis aeruginosa, Microcystis wesenbergii, Trachelomonas volvocina, Trachelomonas volvocinopsis, Cosmarium granatum, Cosmarium quadratulum var. aplanatum, Cosmarium trilobulatum, Desmodesmus quadricaudata, Pseudulvella americana et Encyonema silesiacum contribuent fortement à l’élévation de densité. Les valeurs de l’indice de diversité de Shannon (H’) et l’Équitabilité (E) varient entre 0,82 à St1 à 3,3 à la station St3 pendant la grande saison sèche et entre 0,25 à la station St1 à 0,83 à la station St3 pendant la grande saison sèche, respectivement.

English title: Spatio-seasonal distribution of micro-algae in Adzopé reservoir (Côte d’Ivoire)Spatio-seasonal dynamics of micro-algae from the raw potable water reservoir of Adzopé, was investigated in this study. The samples were collected monthly from January to December 2005. One hundred eighty six taxa of micro-algae were identified in the temporal survey. At spatial level, micro-algae abundances showed high values downstream and low values in the upstream. At the seasonal level, in general, micro-algae densities showed maximum values during the long dry season and the short rainy season corresponding to high concentrations of nitrates and orthophosphates. In generally, abundance was dominated by taxa like Geitleribactron periphyticum, Microcystis aeruginosa, Trachelomonas volvocina, Trachelomonas volvocinopsis, Cosmarium granatum, Cosmarium trilobulatum, Desmodesmus quadricaudata, Pseudulvella americana and Encyonema silesiacum. Values of diversity (H’) and evenness (E) indexes varied between 0.82 at St1 to 3.3 at St3 during long dry seasons and 0.25 at St1 to 0.83 at St3 during long dry season, respectively.
Laboratory Atmospheric Levels of Formaldehyde in Selected Laboratories used by Medical Students in a Tertiary Institution in Edo State, Nigeria
Authors: Ebojele F.O. , Iyawe V.I.
Published: February 2022

This study was conducted to measure the laboratory atmospheric levels of formaldehyde in selected laboratories used by medical students in a tertiary institution in Edo state, Nigeria during the course of their medical training using a formaldehyde gas meter (EXTECH FM 200) ensuring that the laboratories served as the test groups while the lecture theatre served as the control. Data obtained from this study shows that medical students are exposed to various levels of formaldehyde in the different laboratories (Anatomy laboratory 1.71±0.11ppm; Histopathology laboratory 1.96±0.02ppm; Medical Biochemistry laboratory 0.07±0.003ppm and Physiology laboratory 0.05±0.002ppm) and these values are above the recommended limit prescribed by standard organizations. Hence, it was therefore concluded that measures should be taken to ensure reduction of formaldehyde air levels in the Anatomy and Histopathology laboratories in order to protect the medical students from the harmful effect of formaldehyde.
Solution of One-Dimensional Contaminant Flow Problem Incorporating the Zero Order Source Parameter by Method of Eigen-Functions Expansion
Authors: Jimoh O.R. , Shuaibu B.N.
Published: February 2022

A semi – analytical study of a time dependent one – dimensional advection – dispersion equation (ADE) with Neumann homogenous boundary conditions for studying contaminants flow in a homogenous porous media is presented. The governing equation which is a partial differential equation incorporates the advection, hydrodynamic dispersion, first order decay and a zero order source effects in the model formulation. The velocity of the flow was considered exponential in nature. The solution was obtained using Eigen function expansion technique after a suitable transformation. The results which investigate the effect change in the parameters on the concentration was discussed and represented graphically. The study revealed that as the zero order source coefficient increases, the contaminant concentration decreases with time.
Identification and Characterization of Bioactive Components in Datura stramonium Leaves: an insight into Drugs Discovery
Authors: Okpashi V.E. , Oyo-Ita E.E.A. , Jones B.B. , Obeten U.N. , Ucho K.M. , Ofoelo L.I.
Published: February 2022

Medicines from plants help in treating ailments, but to utilize them effectively in the management of diseases requires the identification of potent phytochemicals relative to conventional drugs. These phytochemicals are compared with synthetics drugs in line with their treatment regimen. An investigation was designed to identify, and characterized the different phytochemicals in Datura stramonium (Jimson weed) leaves and compared them with conventional or standard drugs. The identified phytochemicals were blasted on the drugs bank website to find their correlation and relativity. GC/MS technique was used to analyze the phytochemicals. The results showed 80 different phytochemicals belonging to several categories of phytochemicals - alkaloids, flavonoids, terpenoids, saponins, amine, and steroids. The flavonoid class had - 1.24% of 5H-Dibenzo[c, f][1, 2] diazepine, 3, 8 dichloro-6,11-dihydro, at 3.702 RT, Alkaloid class has – 2.98% 2,6-Dibromobenzoquinone was detected at 4.403 RT, steroid – 2.98% Acetanilide, 2-chloro-4'-nitro- at 4.403 RT was obtained and Terpene – 2.05% of Methyl-beta.-[N-methylanilino]acrylate was detected at 4.719 RT, respectively. Most of the identified phytochemicals matched with synthetic drugs and confirmed the purpose of their applicability in traditional medicine. Considering the presence of numerous components and their correlation with conventional drugs, one can infer that this plant species has a good therapeutic application and can be utilized for health benefits.
Using Time-Series Analysis to Assess the Extent of Climate Variability and Climate Change in Bayelsa State, Nigeria
Authors: Agbonaye A.I. , Izinyon O.C.
Published: February 2022

Time series analysis is a useful statistical tool in the assessment of climate variability and climate change. This study applied a time series analysis to rainfall and temperature data in the Bayelsa State of Nigeria. Since NIMET has only one gauging station in the state, Climate Research (CRU 0.5× 0.5) gridded data for 28 locations from 1956 to 2016 were used. They were sorted, validated with NiMet data, and utilized for analyses of various time series techniques such as Mann-Kendal, Spearman’s Rho, Linear Regression, Thei-Sen Slope Cumulative sum, Cumulative Deviation, Rank Sum, Student’s (t-test) and spectral analysis. The results obtained revealed that there had been increasing temperature and abrupt climatic changes in the state, especially in the 1976-1985 decade, with 1980 as the most probable year of abrupt change. The hottest decade was 1986-1995, with an average temperature change of 0.14856 oC/decade, while the coolest decade was 1976-1985 with an average Temperature change of -0.01723 oC/decade. Also, there had been some changes in rainfall, with the wettest decade occurring in 1986-1995 with an average rainfall change of 61mm/decade, while the driest decade occurred in 1976-1985 with an average rainfall change of 14.08 mm/decade. The output of spectral analysis showed that the most Significant Periodicity for Rainfall and Temperature was 15 years. The result further revealed that there was high rainfall variability with a coefficient of variability of 62.74%. These rainfall fluctuations have implications for coastal flooding, quality, and quantity of available groundwater in the state. These results are useful to planners and policymakers in creating awareness of climate change's impact on rainfall in the study area
Access to Safe Drinking Water in Developing Countries: A Comparative Analysis of the Urban and Rural Areas of Zaria, Kaduna State, Nigeria
Authors: Iduseri E.O. , Abbas I.I. , Izunobi J.U. , Ogedegbe S.O. , Ogbonna D.O.
Published: February 2022

Water is a “sin qua non” for virtually all human activities; a pre-requisite for sustainable development as the consequences of safe water for health, productivity and quality of life as well as implications for economic development are enormous. This study investigated the sources of water supply and challenges faced by inhabitants in accessing these water sources in three districts each of urban and rural Zaria, Nigeria, and compared the results. Descriptive statistics and average mean score (AMS) technique was applied, and requisite data presented in frequency and percentage tables. The results revealed that the urban dwellers had to travel longer distances, than the rural dwellers, to source water and that the sources of water supply varied with the season. Whilst the urban areas accessed wells and water vendors in the wet and dry seasons, respectively, for non-domestic water supply and water vendors for domestic water supply; all year round, residents of the rural areas sourced non-domestic water supply from rainfall in the rainy season and streams in the dry season. Conversely, wells and water vendors were accessed in the wet and dry seasons, respectively, for rural domestic water supply. The corollary is that water vendors and wells are the predominant sources of water in Zaria, Nigeria. The methods of water purification employed by the communities sampled and their challenges to safe and adequate water supply are discussed; and plausible solutions are proffered. In addition, some recommendations to mitigate poor access to water are also volunteered.
Determinants of Knowledge and Use of Information Communication Technology at Eco-destinations in Old Oyo National Park, Ikogosi Warm Spring Resort and Lacampagne Tropicana in Nigeria
Authors: Oyebode A. , Adeyemo A.I. , Oladeji S.O.
Published: February 2022

Information Communication Technology has become significant to the development and growth of modern tourism. This study aimed to examine the knowledge and use of information and communication at Old Oyo National Park, Ikogosi Warm Spring Resort and Lacampagne Tropicana by using structured questionnaire directed at fifty percent of the total members of staff at the sites. Data indicated that majority of the staff at Old Oyo National Park (82.9%), Ikogosi Warm Spring Resort (95%) and Lacampagne Tropicana (88.9%) were knowledgeable about the use of information and communication technology especially the use of internet and social media. The staff were also a little competent with the use of Information and Communication Technology at Old Oyo National Park (45.7%), Ikogosi Warm Spring Resort (50%) and Lacampagne Tropicana staff (44.4%). Furthermore, the socio-demographic characteristics of the staff has a significant relationship with their knowledge on the existence of Information Communication Technology at the sites. The management need to organize proper trainings for the staff on the use of Information and Communication Technology so as to improve satisfaction of tourists.
Equilibrium, Kinetic and Thermodynamic Studies of Dyes in Aqueous Solution onto Iron Nanocomposite Stabilized by Irvingia gabonensis Leaf Extract
Authors: Adowei P. , Ebong S.E. , Obuzor G.U.
Published: February 2022

Elimination of dyes in contaminated water or wastewater has become a universal challenge because of their colouration, toxicity, mutagenicity and carcinogenicity when discharged into the recipient environment without treatment and several technologies have been developed to deal with this problem. This paper reports the potential of exploring the use and comparison of conventional iron zero-valent (nZVI) nanoparticle and Irvingia gabonensis stabilized iron nanocomposite (Ig-nZVI) for the elimination of methyl red (MR) and methyl orange (MO) dyes in aqueous solution under effect of different experimental conditions of adsorbent dosage, initial dye concentrations, pH, contact time and temperature. Data obtained show an increase in percent dye elimination as the amount of adsorbent increased. The optimal removal of MR and MO occurred in ˂ 60 min of the start of each experimentation, obtained at a maximum pH of 5.1 at 98.5% and 80.6% for adsorbent dosage of 0.3g/50 mL and 20 mg/L initial dye concentration at temperature of 27oC. The experimental data fitted the Lamgmuir isotherm with maximum adsorption capacity (qmax) of 166.7mg/g (Ig-nZVI) and 83.35 mg/g (nZVI) for MR while 128.21 mg/g (Ig-nZVI) and 40.02.5 mg/g (nZVI) were obtained for MO. Kinetics studies showed that the removal of MR and MO fitted the pseudo second-order model. The adsorption of MR and MO were endothermic and spontaneous with enthalpy values of 3.39kJ/mol (Ig-nZVI) and 776.26kJ/mol (nZVI) and standard Gibbs free energy values of -5.95kJ/mol (Ig-nZVI) and -12.00kJ/mol (nZVI). Thermodynamic studies (ΔG < 0, ΔH < 0, ΔS > 0) implied a spontaneous and exothermic process in nature. The adsorption of MO was endothermic and spontaneous with enthalpy values of 31.70kJ/mol (Ig-nZVI) and 20.91kJ/mol (nZVI) and standard Gibbs free energy values of -5.92kJ/mol and -7.07kJ/mol for Ig-nZVI and nZVI respectively. Adsorbent produced from leaf extracts of African mango tree (Irvingia gabonensis) and stabilized by iron oxide could be an attractive option for elimination of dye from industrial effluents.
Evaluation of Poultry Manure and Cow Dung on Solanum lycopersicum L Planted on Spent Oil Polluted Soil
Authors: Fayinminnu O.O. , Isienyi N.C. , Aigbokha F.O. , Adediran A.A.
Published: February 2022

Pollution from Spent Lubricating Oil (SLO) is one of the major problems farmers encounter in Nigeria. The study is a completely randomized design with Ibadan Local tomato seedlings grown on the following treatments: 0 ml SLO (control), 75ml SLO, 35g of poultry-manure + 75ml SLO, 35g of cow-dung + 75ml SLO, and 4g of NPK + 75ml SLO replicated four times. Physico-chemical parameters of the soil, poultry manure (PM) and cow-dung (CD), heavy metals, and Total-Petroleum-Hydrocarbon (TPH) were determined before and after pollution using standard procedures. Tomato seedlings were transplanted into pots of amended soil with SLO (5 kg/2 plants) and monitored till maturity. Data were taken on growth, yield parameters and analyzed using ANOVA (p<0.05). Results showed significant differences among the treatments. The soil textural class was sandy-loamy with pH (7.2). Tomato in control plots had the highest values 48.30cm plant-height (PH), number-of-leaves (82.63) (NOL), number-of-fruits (0.98) (NOFR) and fresh-weight (0.55g) (FW). Tomato plants grown on CD amended had the lowest 14.40 cm PH, SLO at 75 ml had 6.00 and 1.71cm for NOL and SD, respectively. The NOFR 0.70 value was from PM amended, FW 0.10g was from SLO at 75ml. Heavy-metals bioaccumulation ranges were: Cu 3.00-36.61mg/kg and Zn 15.00-303.79mg/kg. The final TPHs ranged from 181.66 -1350.00mg/kg, while % TPH removal ranged from 4.69- 53.18%. Cow-dung treated soil reduced the amount of copper and zinc present compared with spent oil soil. The growth performance of tomatoes in this study suggests that soil amendment should be encouraged.
Changes in Oxidative Stress Parameters in Wistar Rats Administered Soft Drink and Menthol Candy
Authors: Isoje E.F. , Okoro I.O.
Published: February 2022

The present study aimed to evaluate changes of stress oxidative enzymes and electrolytes of wistar rats administered soft drink and menthol candy. Seventy Wistar rats of weight between 125g and 175g were utilized for the study. The rats were allowed to acclimatize for seven days. The rats were divided into 10 groups of seven rats as follows: Group 1: normal control, Group 2, 3 and 4 were given 8ml, 5 and 2.5ml/kg body weight lacasara. Group 5, 6 and 7 were given 0.3g, 0.22g and 0.11g/kg body weight tom-tom candy. Group 8, 9 and 10 were administered 0.34g in 8ml, 0.22g in 5ml and 0.11g in 2.5ml/kg body weight of tom-tom mix with lacasara respectively. Treatment with tom-tom, lacasara and tom-tom mix with lacasara at various doses was carried out for 42 days. Electrolyte, creatinine and urea in the serum, superoxide dismutase (SOD), catalase (CAT) and malonyldialdehyde (MDA) in liver and kidney ware determined. The results showed significant increase in serum Na+, K+, Cl-and LPO, decrease in SOD, and CAT, in the liver and kidney of groups 2, 3, 5, 6, 8, 9 and 10 compared to control. Furthermore, significant decrease was observed in LPO and increase SOD and CAT of group 7 in the liver and kidney compared to group 5 and 6. There were no significant difference in creatinine and urea in the serum of group 7 compared to group 5 and 6. In conclusion, chronic consumption of tom-tom, lacasara or tom-tom mix with lacasara induced oxidative stress. This effect was confirmed by kidney histological study, showing inflammation of proximal tubule and tubular cells.
Effect of dexmedetomidine pretreatment on a rat model of myocardial ischemia-reperfusion injury
Authors: Chen Jingxia , Liu Wenyan , Wang Shuzhen , Zhang Zidong , Li Weiguo
Published: February 2022

Purpose: To study the effect of dexmedetomidine pretreatment on a rat model of myocardial ischemia-reperfusion injury (IRI)

Methods: Three groups of SD rats (n = 48; mean body weight = 275 ± 25 g) were used (16 rats each): sham, IRI, and dexmedetomidine groups. Ischemia-reperfusion injury (IRI) was established via ligation of left anterior coronary artery. Rats in dexmedetomidine group were treated with single i.p. injection of dexmedetomidine (100 μg/kg) 30 min before induction of IRI. Serum levels of IL-1β, IL-6 and TNF-α were determined by enzyme-linked immunosorbent assay (ELISA). Western blotting was used to determine the protein expressions of bcl-2 and bax, while histopathological changes in rat myocardial tissue were determined with H&E staining.

Results: Serum TNF-α, IL-1β and IL-6 levels were significantly up-regulated in IRI rats, relative to sham rats, but were decreased by dexmedetomidine (p < 0.05). Dexmedetomidine significantly reduced the level of malondialdehyde (MDA) in myocardial tissues of IRI rats, but it increased superoxide dismutase (SOD) activity (p < 0.05). It also markedly increased bcl-2 protein level, while the protein expression of bax was decreased (p < 0.05). Results of H & E staining showed that dexmedetomidine significantly mitigated IRI-induced damage.

Conclusion: Dexmedetomidine mitigates myocardial IRI in rats through suppression of inflammatory and apoptotic changes, and enhancement of physiological antioxidant potential. This finding may be useful for the management of myocardial ischemia-reperfusion injury.
Anti-hypertensive effect of Morus alba L extract in rats
Authors: Pei Sheng-li , Kan Fang , Yue Chun-jiang
Published: February 2022

Purpose: To investigate the probable antihypertensive effects of Morus alba L. extract (MALE) in renovascular hypertensive rats, and the mechanism involved in the reduction of blood pressure.

Methods: The two-kidney one-clip (2K1C) Goldblatt model of renovascular hypertension was used in Wistar rats. The 2K1C group rats were treated with captopril (30 mg/kg), and Morus alba extract (75 and 150 mg/kg) daily for 6 weeks by intragastric administration. Systolic (SBP) and diastolic blood pressure (DBP) were measured by the tail-cuff method. Urine creatinine and urea of the rats were measured by enzyme-linked immunosorbent assay (ELISA). Superoxide dismutase (SOD) and malondialdehyde (MDA) were also evaluated using standard techniques.

Results: In the captopril- and extract-treated groups, blood pressure decreased progressively over the course of the 6-week treatment period compared with that of the control rats (p < 0.01). The extract at 150 mg/kg also significantly (p < 0.05) increased plasma SOD activity but decreased plasma MDA concentration. Renal function significantly (p < 0.01) improved following captopril and extract (150 mg/kg) treatment.

Conclusion: The results suggest that Morus alba extract exerts its antihypertensive effect in rats by inhibiting endothelin (ET)-converting enzyme and via its antioxidant activity. Thus, the plant extract has some potentials for development into a new drug in for use in humans.