QUANTITATIVE ASSESSMENT OF LABORATORY CHEMICAL WASTE

Using the example of a specific laboratory, the problem of the formation and accumulation of chemical waste as a result of its testing activities is considered. It has been shown that during the year, more than 100 kg of chemical reagents belonging to substances of different chemical classes, having different physical states and degrees of danger, are consumed to test agricultural and food products. It is recommended to develop standard laboratory regulations on accounting, collection and storage methods, and methods of disposal of the resulting residues of laboratory chemicals

A Mechanism to Improve the Performance of IEEE 802.11 MAC Protocol

Ad hoc networks are gaining popularity due to their less cost and ease deployment. Efficiency of these networks depend on the performance and reliability of the medium access control (MAC) protocol applied in such networks. Since the channel is shared by nodes, an efficient MAC should allow the nodes to access channel without degrading the performance. The performance of IEEE 802.11 gets degraded due to the presence of hidden and exposed terminal. IEEE 802.11 DCF was designed to overcome these problem using a virtual carrier sensing mechanism. Though IEEE 802.11 DCF is able to overcome the hidden and exposed terminal problem, the throughput and channel utilization is lower due to the inability of the hidden and exposed node to either transmit or receive. In this paper we proposed a mechanism that permits the hidden node to transmit and the exposed node to receive. The proposed mechanism also overcome the RTS induced and CTS-induced problem. We performed extensive simulation using NS-2 simulator. It is observed that the proposed scheme outperforms 802.11 DCF in-terms of throughput and packet delivery ratio with marginally increased in control overhead

Essais de génotoxicité in vitro et in vivo applicables à l'environnement hydrique

Cet article est une revue des essais in vitro et in vivo utilisés pour évaluer le caractère génotoxique des micropolluants des milieux environnementaux relatifs aux eaux continentales et marines, rejets liquides d'origine domestique, industrielle ou agricole, sédiments de rivières et boues de stations de traitement d'épuration.Les essais in vitro réalisés sur cellules eucaryotes ou procaryotes sont fondés sur la détection des mutations géniques et chromosomiques, ou la mesure des adduits à l'ADN. Ils constituent des systèmes d'épreuve miniaturisés qui requièrent des volumes d'échantillons faibles; ils se prêtent ainsi au dépistage à grande échelle de la génotoxicité et à l'étude des concentrats et des extraits préparés à partir des milieux contaminés. Ils sont cependant moins bien adaptés à la prédiction de l'impact des micropolluants sur l'environnement.La recherche de conditions d'essai plus proches de la réalité environnementale a conduit au développement des essais in vivo réalisés sur organismes supérieurs, mollusques, poissons ou amphibiens, qui évaluent un potentiel génotoxique à partir d'études cytogénétiques ou d'études du caryotype des organismes exposés.Les critères de génotoxicité étudiés in vitro peuvent être utilisés dans le cadre d'études écoépidémiologiques, sur le terrain, afin d'évaluer l'impact réel des micropolluants présents dans les milieux environnementaux sujets à des contaminations d'origines diverses.This review deals with in vitro and in vivo genotoxicity bioassays carried out to evaluate the genotoxic potential of polluted environmental samples : continental and marine waters, domestic and industrial wastewaters, aquatic sediments and sludges of urban or industrial wastewater treatment plants.The end-points of the in vitro and in vivo assays are : genetic alterations, i.e. reverse and forward mutations, DNA adducts or chramosomic damages, i.e. chromosomic aberrations (AC), micronuclei (MN) and sister chromatid exchanges (SCE).The in vitro assays generally detect adverse effects on DNA only alter concentration or extraction of micropollutants. They constitute miniaturized tools, rapid and easy to use, thus well-suited for large screening studies. In vitro genotoxicity bioassays requiring only small volumes of samples are therefore systems of choice for testing concentrates or extracts from environmental contaminated samples. Among the in vitro assays reviewed, the Salmonella typhimurium gene mutation test is the most often used to assess the genotoxic potential of contaminated samples. However, genotoxicity tests performed on eukaryotic cell cultures are more relevant than those using bacteria for evaluating environmental pollution. The use of fish cell fines appears superior to the use of mammalian cells for assessing an aquatic impact.In vitro bioassays, whether performed on prokaryotic or eukaryotic cells, are limited for predicting the possible impact of genotoxic pollutants on the environment. It is clear that it is difficult to extrapolate in vitro bioassay results to higher organisms in which the response obtained integrates effects of complex metabolizing systems, hormonal regulation and immunological defenses.Therefore, genotoxicity studies performed with aquatic organisms such as molluscs (Mytilus sp.), fish (Umbra pygmaea, Notobranchius rachowi) or amphibians (Pleurodeles waltl) appear more representative of environmental conditions. The genotoxicity end-points of in vivo assays are mainly cytogenetic damage such as the SCE, AC or MN but also take into account DNA adducts. Direct testing of environmental samples without preconcentration is possible with in vivo assays. This means that factors such as bioavailability and metabolism will be integrated direcrly in the response of these assays. Hence, these in vivo assays are more sensitive titan in vitro genotoxicity tests. However, in vivo tests require important volumes of sample and it will be difficult or almost impossible to apply them for testing concentrates or sample extracts, generally only available in small quantities. An interesting area of application of in vivo assays is field studies and ecoepidemioiogy. In this respect, they would constitue an a posteriori control system of pollution effects, assuming that suitable control areas are available to eliminate the influence of confounding factors.As a general conclusion, if is important to emphasize the interest of using both in vitro and in vivo bioassays for evaluating the genotoxicity of contaminated environmental samples. This rationale is based on the fact that in vitro bioassays are well adapted for genotoxicity screening or concentrates and extracts testing, white in vivo tests are interesting because of their better representativity in terms of environmental conditions of exposure to pollutants

PERBEDAAN HASIL BELAJAR SISWA MODEL PEMBELAJARAN STAD DENGAN STRATEGI BELAJAR RECIPROCAL TEACHING DAN MODEL PEMBELAJARAN KONVENSIONAL DENGAN METODE CERAMAH PADA MATA DIKLAT DASAR-DASAR ELEKTRONIKA DIGITAL DI SMK SUNAN DRAJAT LAMONGAN

Abstrak Penelitian ini bertujuan untuk mengetahui perbedaan hasil belajar siswa dengan menggunakan model pembelajaran STAD dengan strategi belajar reciprocal teaching dan model pembelajaran konvensional dengan metode ceramah pada mata diklat dasar-dasar elektronika digital di SMK Sunan Drajat Lamongan. Metode yang digunakan adalah quasi eksperimental design dengan rancangan penelitian yang digunakan yaitu “Non Equivalent Control Group Design”. Populasi dalam penelitian ini adalah seluruh siswa SMK Sunan Drajat Lamongan. Diambil sampel penelitian ini adalah kelas X TEI SMK Sunan Drajat Lamongan tahun pelajaran 2013/2014. Untuk kelas eksperimen adalah kelas X TEI 1 dan untuk kelas kontrol adalah kelas X TEI 2. Sedangkan untuk mengetahui perbedaan hasil belajarnya digunakan teknik analisis data uji-t. Hasil selisih post-test dengan pre-test dianalisis dengan uji normalitas dan homogenitas, berdasarkan analisis tersebut didapatkan semua kelas berdistribusi normal dan homogen. Hasil analisis uji-t yaitu selisih hasil belajar post-test dengan pre-test menggunakan strategi belajar reciprocal teaching mempunyai nilai rata-rata sebesar 18,1 lebih baik dibanding dengan selisih hasil belajar post-test dengan pre-test yang menggunakan metode ceramah dengan nilai rata-rata 14,7. Dapat disimpulkan bahwa hasil belajar dengan menerapkan strategi belajar reciprocal teaching lebih tinggi daripada hasil belajar siswa yang menggunakan metode ceramah karena mampu meningkatkan hasil belajar siswa dengan selisih rata-rata nilai kemajuan belajar sebesar 3,4 dan aktivitas selama proses pembelajaran dengan strategi belajar reciprocal teaching selama 4 kali pertemuan dikategorikan dalam kategori aktif dengan presentase sebesar 86,7% dan kategori aktivitas baik sebesar 80%. Kata kunci : Pembelajaran Kooperatif, Pembelajaran Kooperatif tipe Student Teams Achievement Divisions (STAD), Startegi Belajar, Strategi Reciprocal Teaching, Hasil belajar. Abstract This research was conducted to know the differences of students' achievement between in STAD learning technique with Reciprocal Teaching Strategy and Conventional Learning Strategy by using Lecture Method in Digital electronic Basic Training Lesson in SMK Sunan Drajat lamongan. The method that used was Quasi Experiment Design and The research planning was Non Equivalent Control Group Design. The population in this research was the students in grade X TEI in SMK Sunan Drajat lamongan time table 2013/2014. Whereas, the experiment class was class X TEI 1 and the control class was class X TEI 2. Moreover, to find out the difference of students' acievement, the researcher used Data Analysis-t Technique. The deviation result between post-test and pre-test was analyzed by using normality test and homogeneity. The analyze result in t-technique was deviation result between post test and ore test by using Reciprocal Teaching Strategy had average 18,1 better than Lecture Method. It had average 14,7. It can be concluded that by applying Reciprocal Teaching can increase more students's achievement than applying Lecture Method. Because it had average values of advances 3,4 and for four times teaching and learning activities can be categorized as an active active activities with percentage 86,7 % and percentage of a good activities in the amount of 80 %. Key Word : Cooperative Learning, Cooperative Learning Type Student Teams Achievement Divisions (STAD), Learning Strategy, Reciprocal Teaching Strategy, Students' Achievement.

Effect of Neuromuscular Electrical Muscle Stimulation on Energy Expenditure in Healthy Adults

Weight loss/weight control is a major concern in prevention of cardiovascular disease and the realm of health promotion. The primary aim of this study was to investigate the effect of neuromuscular electrical stimulation (NMES) at different intensities on energy expenditure (oxygen and calories) in healthy adults. The secondary aim was to develop a generalized linear regression (GEE) model to predict the increase of energy expenditure facilitated by NMES and identify factors (NMES stimulation intensity level, age, body mass index, weight, body fat percentage, waist/hip ratio, and gender) associated with this NMES-induced increase of energy expenditure. Forty sedentary healthy adults (18 males and 22 females) participated. NMES was given at the following stimulation intensities for 10 minutes each: sensory level (E1), motor threshold (E2), and maximal intensity comfortably tolerated (E3). Cardiopulmonary gas exchange was evaluated during rest, NMES, and recovery stage. The results revealed that NMES at E2 and E3 significantly increased energy expenditure and the energy expenditure at recovery stage was still significantly higher than baseline. The GEE model demonstrated that a linear dose-response relationship existed between the stimulation intensity and the increase of energy expenditure. No subject’s demographic or anthropometric characteristics tested were significantly associated with the increase of energy expenditure. This study suggested NMES may be used to serve as an additional intervention for weight loss programs. Future studies to develop electrical stimulators or stimulation electrodes to maximize the comfort of NMES are recommended

Fusion of Higher Order Spectra and Texture Extraction Methods for Automated Stroke Severity Classification with MRI Images

This paper presents a scientific foundation for automated stroke severity classification. We have constructed and assessed a system which extracts diagnostically relevant information from Magnetic Resonance Imaging (MRI) images. The design was based on 267 images that show the brain from individual subjects after stroke. They were labeled as either Lacunar Syndrome (LACS), Partial Anterior Circulation Syndrome (PACS), or Total Anterior Circulation Stroke (TACS). The labels indicate different physiological processes which manifest themselves in distinct image texture. The processing system was tasked with extracting texture information that could be used to classify a brain MRI image from a stroke survivor into either LACS, PACS, or TACS. We analyzed 6475 features that were obtained with Gray-Level Run Length Matrix (GLRLM), Higher Order Spectra (HOS), as well as a combination of Discrete Wavelet Transform (DWT) and Gray-Level Co-occurrence Matrix (GLCM) methods. The resulting features were ranked based on the p-value extracted with the Analysis Of Variance (ANOVA) algorithm. The ranked features were used to train and test four types of Support Vector Machine (SVM) classification algorithms according to the rules of 10-fold cross-validation. We found that SVM with Radial Basis Function (RBF) kernel achieves: Accuracy (ACC) = 93.62%, Specificity (SPE) = 95.91%, Sensitivity (SEN) = 92.44%, and Dice-score = 0.95. These results indicate that computer aided stroke severity diagnosis support is possible. Such systems might lead to progress in stroke diagnosis by enabling healthcare professionals to improve diagnosis and management of stroke patients with the same resources

Fast split background calibration for pipelined ADCs enabled by slope mismatch averaging technique

International audienceA slope mismatch averaging technique which reduces the calibration time and simplifies the digital calibration circuitry in split ADC calibration is introduced. The technique is a direct operation to perform split ADC calibration in pipelined analogue-to-digital converters (ADCs) without any feedback, thus achieving a significant reduction in calibration time