3,054 research outputs found
Multiple logistic regression model to predict risk factors of oral health diseases
To analysis the dependence of oral health diseases i.e.
dental caries and periodontal disease on considering the number of riskfactors through the applications of logistic regression model. Method: The cross sectional study involves a systematic random sample of 1760 permanent dentition aged between 18-40 years in Dharwad, Karnataka, India. Dharwad is situated in North Karnataka. The mean age was 34.26±7.28. The risk factors of dental caries and periodontal disease were established by multiple logistic regression model using SPSS statistical software. Results: The factors like
frequency of brushing, timings of cleaning teeth and type of toothpastes are signifi cant persistent predictors of dental caries and periodontal disease. The
log likelihood value of full model is –1013.1364 and Akaike’s Information Criterion (AIC) is 1.1752 as compared to reduced regression model are
-1019.8106 and 1.1748 respectively for dental caries. But, the log likelihood value of full model is –1085.7876 and AIC is 1.2577 followed by reduced Romanian Statistical Review nr. 5 / 2012 regression model are -1019.8106 and 1.1748 respectively for periodontal
disease. The area under Receiver Operating Characteristic (ROC) curve for the dental caries is 0.7509 (full model) and 0.7447 (reduced model); the ROC for the periodontal disease is 0.6128 (full model) and 0.5821 (reduced model
Nonequilibrium Phase Transitions in a Driven Sandpile Model
We construct a driven sandpile slope model and study it by numerical
simulations in one dimension. The model is specified by a threshold slope
\sigma_c\/, a parameter \alpha\/, governing the local current-slope
relation (beyond threshold), and , the mean input current of sand.
A nonequilibrium phase diagram is obtained in the \alpha\, -\, j_{\rm in}\/
plane. We find an infinity of phases, characterized by different mean slopes
and separated by continuous or first-order boundaries, some of which we obtain
analytically. Extensions to two dimensions are discussed.Comment: 11 pages, RevTeX (preprint format), 4 figures available upon requs
Pengaruh Penyiangan Dan Suhu Penyimpanan Terhadap Mutu Kimiawi, Mikrobiologis Dan Organoleptik Ikan Tongkol (Auxis Tharzard, Lac)
Ikan tongkol merupakan salah satu bahan pangan yang dikonsumsi masyarakat dan jika dibiarkanpada suhu kamar, maka terjadi proses penurunan mutu menjadi busuk. Ikan yang sudah mengalami prosespembusukan, bila dikonsumsi dapat menimbulkan keracunan (Histamine fish poisoning). Keracunan inidisebabkan oleh kontaminasi bakteri pathogen dengan dekarboksilasi asam amino histidin oleh enzimhistidin dekarboksilase menghasilkan histamin. Bakteri ini banyak terdapat pada anggota tubuh manusiayang tidak higienis, kotoran/tinja, isi Perut ikan, insang serta peralatan yang tidak bersih.Penelitian eksperimental dengan pola faktorial, yaitu faktor P adalah faktor penyiangan dengan 2 taraf,tanpa penyiangan dan penyiangan, sedangkan faktor T adalah suhu penyimpanan dengan 3 taraf yaitu suhupenyimpanan 30oC, 15oC dan 0oC.Analisis statistik terhadap mutu kimiawi seperti kadar histamin, kadar total volatil bases (TVB) dantrimetilamin (TMA) menunjukkan perbedaan nyata (P<0,05) pada pengaruh penyiangan dan suhupenyimpanan. Terjadi peningkatan kadar histamin, kadar TVB dan TMA selama penelitian. Selamapenelitian terjadi peningkatan jumlah koloni bakteri, jumlah Coliform, kecuali bakteri Vibrioparahaemolyticus negatif. Perlakuan penyiangan dan suhu penyimpanan 0oC memiliki mutu kimiawi,mikrobiologis terbaik sampai hari ke 10 serta masih diterima panelis.Hubungan antara kadar histamin dengan jumlah bakteri mempunyai hubungan sangat kuat, ditunjukkandengan nilai r ? 0,7 kecuali kadar histamin dengan waktu memiliki hubungan agak lemah r ? 0,5.Keamanan ikan tongkol dengan penerapan teknologi tepat guna berupa tanpa penyiangan danpenyiangan pada suhu 30oC hanya aman untuk dikonsumsi sampai hari ke 0. Perlakuan tanpa penyiangandan suhu penyimpanan 15oC aman sampai hari ke 4, sedangkan dengan penyiangan aman sampai hari ke 6.Untuk perlakuan tanpa penyiangan dan penyiangan dengan suhu penyimpanan 0oC aman sampai hari ke 10
A review of imperative technologies for wastewater treatment I: oxidation technologies at ambient conditions
Nowadays, due to the increasing presence of molecules, refractory to the microorganisms in the wastewater streams, the conventional biological methods cannot be used for complete treatment of the effluent and hence, introduction of newer technologies to degrade these refractory molecules into smaller molecules, which can be further oxidized by biological methods, has become imperative. The present work aims at highlighting five different oxidation processes operating at ambient conditions viz. cavitation, photocatalytic oxidation, Fenton's chemistry (belonging to the class of advanced oxidation processes) and ozonation, use of hydrogen peroxide (belonging to the class of chemical oxidation technologies). The work highlights the basics of these individual processes including the optimum operating parameters and the reactor design aspects with a complete overview of the various applications to wastewater treatment in the recent years. In the next article of this two article series on imperative technologies, hybrid methods (basically combination of the oxidation processes) will be discussed and the current work forms a useful foundation for the work focusing on hybrid technologies
Thiazole Antibiotic Thiostrepton Synergize with Bortezomib to Induce Apoptosis in Cancer Cells
Thiazole antibiotic, thiostrepton was recently identified as proteasome inhibitor. We investigated the therapeutic potential of the combination of thiostrepton and proteasome inhibitor bortezomib (Velcade) on various human tumor cell lines. Combination of sub-lethal concentrations of thiostrepton and bortezomib induced potent apoptosis and inhibition of long-term colony formation in a wide variety of human cancer cell lines. The synergistic relationship between thiostrepton and bortezomib combination was also quantitatively demonstrated by calculating their combination index values that were much lower than 1 in all studied cell lines. The synergy between these drugs was based on their proteasome inhibitory activities, because thiostrepton modification, thiostrepton methyl ester, which did not have intact quinaldic acid ring and did not inhibit proteasome activity failed to demonstrate any synergy in combination with bortezomib
Direct numerical simulations of statistically steady, homogeneous, isotropic fluid turbulence with polymer additives
We carry out a direct numerical simulation (DNS) study that reveals the
effects of polymers on statistically steady, forced, homogeneous, isotropic
fluid turbulence. We find clear manifestations of dissipation-reduction
phenomena: On the addition of polymers to the turbulent fluid, we obtain a
reduction in the energy dissipation rate, a significant modification of the
fluid energy spectrum, especially in the deep-dissipation range, a suppression
of small-scale intermittency, and a decrease in small-scale vorticity
filaments. We also compare our results with recent experiments and earlier DNS
studies of decaying fluid turbulence with polymer additives.Comment: consistent with the published versio
Enhancement in biodegradability of distillery wastewater using enzymatic pretreatment
A combined treatment technique consisting of enzymatic hydrolysis, followed by aerobic biological oxidation was investigated for the treatment of alcohol distillery spent wash. The enzyme cellulase was used for the pretreatment step with an intention of transforming the complex and large pollutant molecules into simpler biologically assimilable smaller molecules. Batch experiments were performed in order to analyze the influence of various parameters like pretreatment time, enzyme concentration and pH during the pretreatment step on the subsequent aerobic oxidation kinetics. The rate of aerobic oxidation was enhanced by 2.3 fold for the pretreated sample as compared to the untreated sample when the pH during the pretreatment step was maintained at a value of 4.8. Similarly, a two fold increase in the aerobic oxidation rate was found when the effluent was pretreated with the enzyme, without any pH control (i.e. effluent pH of 3,8). The study indicated that the enzymatic pretreatment of the effluent could be one of the successful pretreatments which can lead to enhancement of the rate of the subsequent aerobic oxidation
Assessment of Pesticide Use in Major Vegetables From Farmers\u27 Perception and Knowledge in Dhading District, Nepal
A field study was carried out to assess the pesticide use status in major vegetable crops from farmers\u27 perception and knowledge in Dhading, Nepal in 2019. Field study was carried with 100 commercial farmer\u27s using semi-structure questionnaire by face to face interview. This study was analyzed by categorization of farmers into small holder (51) and large holder (49) groups on the basis of mean area of vegetable cultivation (6.48 ropani). The highest amount of pesticides is needed in tomato in both large holders and small holders according to the farmer\u27s experience. Among the study farmer\u27s, 41% of them spray the pesticides by making a cocktail or mixed method and 56% follow the waiting period of 3-5 days in both of the cases. A significant positive correlation was found at 5% level of significance between the knowledge and practice pattern of waiting period of the pesticides and negative correlation was found between the Personal Protective equipment score and health hazard score. Headache was the major health hazards faced by the farmers which was higher in small holders (66.7%) as compared to the large holders (46.9%). Mask was the most used PPE by the farmer\u27s i.e. by 83% in overall. Fourty three percent of the farmer\u27s throw the pesticide containers in secret place after using of it.The use of PPE was seen lower in small holders as compared to the large holders. This study reveals the necessities of suitable program and policies regarding the knowledge, safe handling and use of pesticide among the farmer\u27s level
On the behaviour, mechanistic modelling and interaction of biochar and crop fertilizers in aqueous solutions
Although the benefits of applying biochar for the purposes of soil conditioning and crop productivity enhancement have been demonstrated, relatively few studies have elaborated on its causal mechanisms, especially on the biochar-fertilizer interaction. Thus, in the present study, the ex-situ adsorptive potential of base activated biochar (BAB) towards plant nutrient immobilization and removal from aqueous solutions was investigated. Napier grass (Pennisetum purpureum) was utilized as the precursor to prepare slow vacuum pyrolysed char and its affinity towards adsorption of urea was examined at various process conditions. Low sorption temperatures, moderate agitation speeds and high initial concentration were seen to favour greater urea uptake by BAB. The sorption was exothermic, physical, spontaneous and had a pseudo-second order kinetic fit. Both surface and intra-particle diffusion governed the removal and immobilization of urea. Furthermore, process mass transfer was limited by film diffusion of urea to the external surface of the BAB. Equilibrium studies suggested that Dubinin-Radushkevich is the most appropriate model to describe the urea-BAB behaviour with maximum uptake, estimated to be 1115 mg·g−1. Through such ex-situ analysis, it could be possible to have prior knowledge, quantification and differentiation of the potential of chars manufactured from various feedstocks. This could then be used as an effective screening step in designing appropriate biochar-fertilizer systems for soil conditioning and help reduce the time and effort spent otherwise in long-term field studies
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