Observation et étude expérimentale de mycobactéries atypiques en aquariums d'eau douce et d'eau de mer

L'eau des aquariums est source de Mycobactéries atypiques qui peuvent être pathogènes pour l'homme et les poissons.Une étude a été réalisée à l'aquarium du Musée de Zoologie de Nancy. La recherche de Mycobactéries a été effectuée dans 40 aquariums équipés de lampes germicides à UV : 11 bassins étaient alimentés en eau douce et 29 en eau de mer. Deux aquariums non équipés de système de désinfection ont également été analysés, les propriétaires de ces derniers ayant présenté un granulome cutané à M. marinum. L'action des UV sur M. marinum en suspension dans l'eau a été testée expérimentalement dans des bassins d'eau douce peuplés de Cichlidés.Pour chaque aquarium, un échantillon de 250 ml a été prélevé. Les cultures après décontamination au lauryl sulfate de soude ont été réalisées sur milieu de Loewenstein.Les résultats indiquent que, quel que soit l'aquarium, la présence de mycobactéries est constante. L'isolement des mycobactéries peut être gêné par la présence d'une flore bactérienne ou fongique importante (≥ 103 U.F.C./ml).Les espèces les plus fréquemment isolées sont M. gordonae et M. fortuitum ; M. kansasii et M. marinum ont rarement été isolées (6140 aquariums). Différents facteurs peuvent intervenir sur la sélection des espèces. La salinité de l'eau limite le développement de certaines espèces, alors qu'elle permet la croissance de M. fortuitum. Dans notre étude, la température de l'eau n'a pas été un facteur sélectif. L'utilisation de lampes UV limite le nombre de Mycobactéries. Dans les bassins expérimentaux, les radiations UV se sont révélées très actives sur M. marinum en présence ou en l'absence de poissons. A l'inverse de M. gordonae, M. fortuitum est rarement isolée en présence d'UV. Un nombre important de poissons par aquarium augmente la flore bactérienne et mycobactérienne.La prévention des infections à Mycobactéries atypiques chez l'homme comme chez les poissons devrait pouvoir être assurée par des mesures d'hygiène élémentaire.Water is a natural habitat of mycobacteria. In aquaria 3 species of atypical mycobacteria are frequently present : M. marinera, M. kansasitand M. fortuitum. They are potential pathogen for fishes and men. Tuberculosis has been recognized as the cause of mortality in marine and fresh water fishes. Clinical signs of fish tuberculosis are variable : ascites, skin ulcerations, skeletal deformities. The human infection is cutaneous granuloma occuring after in jury in aquaria.In the aquaria, of which two patients with cutaneous lesions due to M. marinum were analysed, UV lamps were not used. Many factors have an influence on the number of mycobacterial organisms in aquaria waters : number of fishes per tank, decontamination system, salinity, temperature.To determine the consequence of each factor, a study has been conducted at the “Aquarium du Musée de Zoologie de Nancy”. Research of mycobacteria was carried out in the water of 40 tanks : 11 were supplied with fresh water and 29 with salt water. Each tank was equipped with germicide UV (λ : 253,7 nm) : the intensity was 15 watts for aquaria smaller than 1 000 liters and 36 watts for aquaria larger than 5 000 liters. The effectiveness of UV radiation against M. marinum was tested in 3 experimental fresh water tanks of 280 liters. The first part of the experiment was tested without fish. Tank n° 1 was a control, lamp was switched on during the complete study, M. marinum was not added. In tank n° 2 (with UV) and n° 3 (without UV), 2 ml of M. marinum (of suspension 107 CF/ml) was added. Samples of water were analysed every two weeks. After six weeks tanks n° 2 and n° 3, were prepared for the next study : UV lamps were switched on in n° 2 and switched off in n° 3 both of which were contaminated by M. marinum. After 4 weeks 27 fishes, Cichlids, were introduced in the three aquaria. The day after, M. marinum was added to tanks n° 2 and n° 3. Every week water analysis was done, as well as an identification and quantification of all species of mycobacteria.From each tank 250 ml of water were collected. The water was passed through a 0,2 mµ membrane. The filters were introduced in distilled water and decontaminated by lauryl sulfate. The culture of mycobacteria was grown with Loewenstein medium at 30 and 37 °C. Each colony type was identified by cultural and biochemical characteristics.This study shows the richness in aquaria of mycobacteria; whatever the tanks, mycobacteria presence was constant. In non-treated home aquaria, the presence of mycobacteria was very important, 4 to 6 species per tank, (but in this case M. marinum was not found). In aquaria with UV lamps, the number of species per tank was lower (1 to 3).The growth of mycobacleria could be prevented when the samples were contaminated by fungi and bacteria. However, inability to recover mycobacteria from water occurred only when a massive over-growth by non-mycobacterial contaminant was present (103 CFU/ml). This was the case of non-treated tanks, belonging to patients who developed a chronic granuloma on their hands, M. marinum was not isolated in these aquaria. The evaluation of slowly growing mycobacteria could be altered by the important development of fast growing mycobacteria on the same culture tube. Among isolated species, M. fortuitum and M. gordonae saprophytic strains were frequent; M. kansasii and M. marinum involved in human cutaneous granuloma were unusual, as were the non-pigmented strains of groupe III of Runyon ; M. avium was not isolated.During this study, we observed a relationship between the mycobacteria presence and the cleanness of tank and the fishes population. A great number of fishes per tank was a factor which increased the bacterial and mycobacterial contamination. During this experiment fishes didn't present tubercular-lesions but when a dead fish was examinated, the culture from post-modem samples revealed the presence of M. marinum. The microbiological examination of skip and viscera was negative.The comparison of results in non-treated home tanks and UV treated tanks of the Museum indicates the role of water treatment by UV lamps on the number of isolated mycobacteria.The germicide UV camps are frequently used for the decontamination of tanks. The efficiency is good for bacteria, but unknown for mycobacteria. This study shows that UV radiation decreased the mycobacterial contamination. The species of mycobacteria differ in their sensitivity to UV radiation. In experimental tanks, the results showed the great susceptibility of M. marinum to UV lamps such they were used in aquaria. Presence of fish dues not change the results. If the addition of M. marinum and the lighting of lamps were simultaneous, M. marinum was not isolated in water. If the contamination by M. marinum preceded the lighting of UV lamps, must of bacteria was eliminated in one week and the totality in 4 weeks. For the other species, we observed that the mycobacterial sensitivity to UV light decreases in the following order : quickly growing mycobacteria, photochromogen and scotochromogen strains. During our experimental study, M. gordonae was isolated more frequently when UV lamps were switched on. The results obtained in the 40 tanks with UV lamps allowed the evaluation of the influence of salinity and temperature of water on mycobacterial survival and the selection of species. We did not observed a difference in the concentration of mycobacteria in two types of aquaria, fresh water and salt water. Na Cl is known as an inhibitor of the mycobacterial growth. The sensitivity of strains differs. The salinity of water appears to be a selection factor. M. forfuitum was isolated more frequently in salt water.M. marinum was isolated only in salt water and M. kansasii in fresh water. These results are surprising, as these strains have about the same metabolism. The temperature of water can also be a selection factor for mycobacteria, but in our study the temperature was similar in each aquarium (25°-26°). In this study, we did not observe thermophile strains such as M. avium.Aquarists must be informed of the aquarium contamination by atypical mycobacteria and their role in the evolution of skin lesions after injury of hands and arms. The use of germicide UV lamps improves the bacteriological quality of water

IMPACTS OF POWER SYSTEM-TIED DISTRIBUTED GENERATION ON THE PERFORMANCE OF PROTECTION SYSTEMS

The dispersed integration of smaller power units in the existing utility grid is the new trend. This is largely due to changes in the power generation and distribution markets. The combination of rising cost of new construction, deregulations and improved newer power equipment technologies suitable for deferred expansions make the new trend very attractive to power companies and independent investors. Until recently, other contributions to power distribution systems from such sources as standby units were considered negligible and therefore unaccounted for during the design and operation of power systems. This view has drastically changed, largely due to the increasing penetration levels of these newer technologies termed Distributed Generation Resources. This thesis work is a continuation of ongoing work in the validation of the benefits and pitfalls of grid integrated Distributed Generation using modern modeling and simulation techniques. The proposed simplified but more robust symmetrical components based protection relay system is shown to be immune to the mis-coordination, mis-operation and blinding caused by the bidirectional power flow resulting from the high shares of Distributed renewable resource integration

DIFFICULT TOPICS AND ACHIEVEMENT IN ENGLISH LANGUAGE: THE PERCEPTION OF SENIOR SECONDARY SCHOOL STUDENTS AND TEACHERS IN MAKURDI TOWNSHIP, BENUE STATE, NIGERIA

This study determined which topics in the English language curriculum for senior secondary school are perceived by students and teachers as difficult. It also examined difficult topics vis-à-vis English language achievement. Seven research questions were answered using descriptive statistics and two hypotheses were tested at 0.05 level of significance using t-test statistics. The study involving twelve English language teachers and one hundred and eighty seven students was carried out in Makurdi Township, Benue State, Nigeria during the second term of 2015/16 academic session. A self-developed questionnaire with closed-ended items was used to elicit data. Since the researcher relied on the opinion of the respondents for data collection, survey design was chosen as method of research. The results of the analysis showed that out of the 35 topics selected from the SSCE syllabus and prescribed textbooks for English at that level, teachers perceived 14 as difficult topics, while students perceived 22 as difficult topics. The reasons why they were experiencing difficulty with the topics were poor reading and study skills, absence of motivation, hatred for English language, poor experience with the subject, and poor teaching methods. The study recommended remedial teaching of difficult topics, the use of ICT; retraining of teachers, peer teaching, and professionalization of teachers as steps to improve English language teaching and learning.  Article visualizations

Pragmatic Approach to Use of Mastery Learning Model in Implementation of Social Studies Curriculum for Achievement of Sustainable Development Goal-4 in Nomadic Schools in Maiadua, Katsina State, Nigeria

Acquisition of quality education for all is one of the basic concerns of societies in the world.  This desire is anchored on universal protocol agreement contained in sustainable development goal four (quality education for all). The paper is therefore an attempt to investigate pragmatic approach to use of mastery learning model in implementation of social studies curriculum for achievement of sustainable development goal-4 in nomadic schools in maiadua, katsina state, Nigeria. A descriptive research design involving pre-test and post-test was used for the study. The population of the study was 78 headmasters in the 78 primary schools in the Local government area. Sample for the study was all the 78 headmasters who were purposively selected by virtue of their leadership positions in the schools. A Researcher designed questionnaire was used in data collection. The instrument was validated by two experts in test and measurement and one curriculum expert who were of the rank of senior lecturer and above. Reliability of the instrument was ensured by administering the instrument twice to 30 headmasters in Kurfi local government at interval of two weeks. The data collected was analysed using Pearson moment correlation coefficient. The coefficient of 0.67 was obtained which show that the instrument was reliable. Two objectives with corresponding research questions and hypotheses were raised and formulated respectively to guide the study. The research questions were answered using descriptive statistics: frequency count and percentage, while the hypotheses were tested using chi-square statistic at 0.05 level of significance. The findings of the study revealed that: headmasters’ perception of mastery learning was positive as most of them responded positive to the items on the instrument, they had knowledge of mastery learning instructional model in implementation of Social studies curriculum in Nomadic schools in maiadua, Katsina State, Nigeria, they attempted to put to use knowledge of mastery learning in implementation of Social Studies curriculum in Nomadic schools Katsina State, Nigeria, however they lacked the modern technique used in achievement of the instructional model. Based on the findings the following recommendations were made: deliberate effort should be made to improve the skills of teachers on the acquisition and use of mastery learning instructional strategy by ministry of education through organization of workshops and conferences for the teachers in basic schools. Mastery learning instructional strategy should be given prominence in teacher education programmes in higher tertiary institutions to enable the pre-service teachers acquire necessary knowledge and skill on the strategy and fresh graduates from Colleges of Education employed in nomadic schools should be sensitized on the benefits of mastery learning instructional strategy by school administrators using symposium and other available means to avoid attrition

Image of the Nigeria police as portrayed in Georgie Iortema’s Night Duty

This article presents a literary analysis of Georgie Iotema’s play, Night Duty, which portrays a negative image of the Nigeria Police. The constitutional duty of the Nigerian police is to maintain public safety and public order. In practice, many members of the Nigeria Police are lawbreakers. There are many instances of these law enforcement agents caught fighting, demanding and accepting bribe, killing indiscriminately, and raping women, etc. Disturbed by this development, Georgie Iortema takes a swipe on the Nigeria Police in the book Night Duty, where he reveals artistically the obnoxious and nefarious acts of the men and officers of the Police Force who commonly trample on the rights of the citizens. The present article highlights the negative life of the police that depicts moral bankruptcy, depravity, desperation and misery both in their domestic and public life. The message is poignant and full of moral lessons.Keywords: image, Night Duty, Nigeria police, dram

A STUDY OF STUDENTS,’ CLASS TEACHERS’ AND SUPERVISORS’ PERCEPTIONS AS PREDICTORS OF ENGLISH LANGUAGE STUDENT-TEACHERS’ TEACHING EFFECTIVENESS IN MAKURDI TOWNSHIP IN BENUE STATE, NIGERIA

Abstract Less research has investigated students’ and class teachers’ perception of teaching effectiveness even as the practice is very old and arguments favour it. The present research therefore utilized descriptive survey design and purposively selected 162 secondary school students, 6 English language teachers and 6 teaching practice supervisors to complete three sets of teaching practice evaluation questionnaires that provided data for analysis.  The questionnaires were validated by two experts in measurement and evaluation from Benue State University, Makurdi, and their reliability coefficient using Cronbach’s alpha yielded 0.83 (students’ Questionnaire), 0.85 (teachers’ questionnaire) and 0.81 (supervisors’ questionnaire). Results of the study using multiple regression analysis showed a high positive correlation among students, teachers and supervisors’ indicating multiple predictions of teacher effectiveness.  It was concluded that the practice of seeking diverse views of stakeholders on how student-teachers do their work is far more advantageous than relying on the opinion of only supervisors as it is at present. The study recommended that teaching practice exercise should not be combined with course work.Keywords: teaching practice, effectiveness,   student-teachers, lesson plan

Teachers' and students' attitudes towards reading and writing: Do they correlate to students' achievement in English?

This survey tested the null hypothesis that teachers’ and students’ attitudes towards reading and writing do not simultaneously predict students’ achievement in the English language. The researcher utilized a sample of 38 teachers and 492 senior secondary school students from 12 schools in Benue State, Nigeria, for the study. The researcher developed and utilized the English Language Students’ Attitude Scale (ELSAS), English Language Teachers’ Attitude Scale (ELTAS), and Reading and Writing Achievement Test (RWAT) for data collection. An estimate of internal consistency was obtained through Cronbach’s Alpha and Kuder Richardson’s reliability methods and found to be 0.76 for ELSAS, 0.68 for ELTAS, and 0.81 for RWAT. Data analysis was by multiple regression statistics. The findings revealed that both English language teachers and students have a positive attitude towards reading and writing (F3, 492 = 0.160, p0.05) implying that teachers and students’ attitudes towards reading and writing jointly predicted students’ achievement in the English language in senior secondary schools. To conclude, learning would be facilitated if both teachers and students hold positive attitudes towards reading and writing, and this, in turn, could impact the students’ achievement in the English language. It was recommended that teachers should plan reading and writing instruction that can help students develop positive attitudes to these skills and parents should help in the development of these skills at home

Impact of Class-Wide Peer-Tutoring Strategy on Secondary School Slow Learners’ Performance in Redox Reactions in Funtua, Katsina State- Nigeria

The performance of senior secondary school students in chemistry has been very poor over the years in Nigeria. Teachers’ use of inappropriate instructional strategies and students varied abilities has been identified responsible for this problem. This study examined the impact of Class-Wide Peer-Tutoring Strategy on secondary school slow learners’ performance in redox reactions in Funtua Education Zone, Katsina State, Nigeria. Quasi– experimental design was adopted for the study. The study involved a population of 977 SS2 Students. A of sample of 108 slow learners drawn from two secondary schools were used. Three research hypotheses guided the study. Treatment involved teaching experimental group by trained peer tutors using CWPT while the control group was taught by the teacher using lecture method. Redox Performance Test (REPT) duly validated by experts with a reliability coefficient of 0.85 obtained using test retest method was used for data collection. Hypotheses were tested using t-test at 0.05 levels of significance. Results revealed that slow learners taught by peer tutors using CWPT performed significantly better than those taught by the teachers using lecture method. The study recommended that chemistry teachers should be train through workshops, seminars and conferences on the use of class-wide peer-tutoring strategy in teaching and learning of chemistry

Solving Irreducible Stochastic Mean-Payoff Games and Entropy Games by Relative Krasnoselskii-Mann Iteration

International audienceWe analyse an algorithm solving stochastic mean-payoff games, combining the ideas of relative value iteration and of Krasnoselskii-Mann damping. We derive parameterized complexity bounds for several classes of games satisfying irreducibility conditions. We show in particular that an ε-approximation of the value of an irreducible concurrent stochastic game can be computed in a number of iterations in O(|log(ε)|) where the constant in the O(⋅) is explicit, depending on the smallest non-zero transition probabilities. This should be compared with a bound in O(ε^{-1}|log(ε)|) obtained by Chatterjee and Ibsen-Jensen (ICALP 2014) for the same class of games, and to a O(ε^{-1}) bound by Allamigeon, Gaubert, Katz and Skomra (ICALP 2022) for turn-based games. We also establish parameterized complexity bounds for entropy games, a class of matrix multiplication games introduced by Asarin, Cervelle, Degorre, Dima, Horn and Kozyakin. We derive these results by methods of variational analysis, establishing contraction properties of the relative Krasnoselskii-Mann iteration with respect to Hilbert’s semi-norm

The Multifaceted Hygiene Promotion Program on Knowledge, Attitude, and Practice of Menstrual Health and Hygiene Management Among Girls in Nigeria: A Quasi Experimental Study

Aims: The onset of menstruation is a significant milestone in a girl\u27s life, yet the silence and stigma surrounding it burden young girls by keeping them ignorant of this natural phenomenon. In Kano State, prevailing myths and cultural norms dictate restrictive practices that further exacerbate the challenges associated with menstruation, including limited access to sanitation facilities and hygiene products. This study investigates the effectiveness of the multifaceted hygiene promotion on knowledge, attitude and practice of menstruation among girls in Nigeria. Methods: A quasi-experimental design was employed, with 104 participants divided into intervention and control groups. Pre- and post-intervention assessments, along with a two-month follow-up, were conducted to measure changes in knowledge, attitude and practice concerning menstruation among girls in Nigeria. The intervention group received the multifaceted hygiene promotion program, while the control group received standard education. Descriptive and inferential statistics were used to analyse the collected data of the study. Result: The findings from the baseline data reveal significant gaps in knowledge, negative attitudes, and suboptimal practices regarding menstrual health among the participants, highlighting the pressing need for comprehensive and multifaceted interventions. Conclusions: In conclusion, this study establishes a foundational understanding of the current state of menstrual health knowledge, attitudes, and practices among secondary school girls in Nigeria. The insights gained from the baseline data provide a strong basis for the design and implementation of effective interventions aimed at empowering girls with the knowledge and skills necessary for managing menstruation confidently and hygienically