PSVII-20 Optimization of intestinal permeability assays to study the degree of fasting in gut permeability of unweaned Angus-Holstein bull calves

In-vivo assessments of intestinal permeability can be expensive and time consuming. Additionally, the correct choice of test molecules to use and the optimum sampling time under fasting situations needs be optimized. Fifteen unweaned Angus-Holstein bull calves (44.1 ± 2.0 kg and 14.7 ± 0.63 d) were randomly assigned to 1 of 3 treatments: Control (CT; n = 5): no fasting; fasted during 9 h (FAS9; n = 5); and fasted during 19 h (FAS19; n = 5). All calves were fed 2.5 L of MR and treatments were applied on d -1. Chromium-EDTA (Cr-EDTA), lactulose and D-mannitol were administered orally before blood collection. Samples were taken on d -4 and -1 before fasting and on d 0 and 2, at 60, 120, 180, and 240 minutes. To choose the best test molecule, correlations between serum concentration of the test molecules were used. To decide the optimum sampling time, data from d 0 were used to calculate area under the curve, then data were analyzed with mixed models with fasting degree and sampling time as fixed effects. Correlation between Cr-EDTA and D-mannitol was r= 0.92 (R2=84%), and correlation between Cr-EDTA and lactulose was r= 0.86 (R2=75%). Differences in AUC of Cr-EDTA between CT and t fasting treatments were observed up to 120 min. Differences in AUC of Cr-EDTA between FAS9 and FAS19 were observed later at 240 min. To optimize the intestinal permeability test, the use of only one test molecule might be sufficient. The Cr-EDTA was proposed to optimize the methodology due to price and simplicity of the analysis. The optimum sampling time after Cr-EDTA administration was 120 min when comparing fasting and control, and 240 min when comparing different fasting degrees.

Towards sound use of statistics in nematology

Background Inclusion of the statistical approach in the planning stage of adequate experimental design is crucial for correctly achieving the required conclusions. Modern applied statistics has been used extensively in nematological research worldwide. Although hypothesis testing is still essential to relevant research topics, more emphasis is directed towards other significant issues. Main body Issues of estimating the magnitudes of differences among various treatments, conception of optimum sampling size, determining spatial and temporal distribution of nematode ecology, nematode-host suitability designation, prediction of crop yield loss caused by plant-parasitic nematodes and other effects were discussed. So, this study presents highlights of developments in nematological statistics. Moreover, modern statistics should address issues of other nematology-associated disciplines. For example, statistics applied to compare the reliability of molecularly examined samples showed that fairly low-cost metabarcoding had significantly better accuracy in quantifying and identifying the extracted entomopathogenic nematodes (EPNs) than that of quantitative polymerase chain reaction. Thus, statistics could contribute to a cost-effective, value-added approach to pest management programs. Moreover, an empirical method to improve application strategies of EPNs could be recently modified concerning index of nematode dispersion in terms of the thumb rule value for the nematode-random distribution. Conclusion Common misuses of statistics in both nematological research and reporting could be avoided but useful conclusions via sound and modern statistical analyses of the data should be drawn.

Determination of Optimum Sampling Fraction for Bootstrap Resampling

Lately, there has been much discussion on the bootstrap resampling method, both as a way of estimating standard error and as a way of improving estimations with access to only one sample. However, little is found in literature discussing the size the bootstrap sample should take. This study aims to determine the existence of an optimum sampling fraction for resampling, analysing different estimators and number of resamples. An optimum fraction exists if, and only if, for every estimator and every amount of resamples, a fraction (or region) performs better in every population. Ten random populations were created by adding together different normal, Poisson and exponential distributions such that their means and variances are diverse. A Monte Carlo simulation with ten thousand iterations was done, taking random systematic samples from the populations and from these, bootstrap samples to estimate the mean, variance and respective standard errors. Results show the inexistence of a single optimum fraction. However, it does point to an optimum region for standard error estimation above 37.5%.

INDEKS MITOSIS PUCUK DAUN Hibiscus rosa-sinensis L. VARIASI SINGLE PINK PADA BEBERAPA VARIASI WAKTU

AbstrakHibiscus rosa-sinensis L. atau kembang sepatu merupakan tanaman hias yang memiliki banyak manfaat dan merepresentasikan sifat poliploidi. Tujuan penelitian ini yaitu untuk mengetahui Indeks Mitosis (IM) dan jumlah kromosom pucuk daun H. rosa-sinensis pada beberapa variasi waktu. Indeks Mitosis dan waktu pengambilan pucuk sangat diperlukan untuk studi kromosom karena pada tahap tersebut karakter-karakter kromosom dapat diamati dengan jelas dan mudah dihitung. Waktu pengambilan pucuk yang dilakukan yaitu pada 08:00, 10:00, 12:00, 14:00, 16:00 WIB. Pembuatan sediaan kromosom dilakukan menggunakan metode squash menggunakan pewarna Aceto-orcein. Tahapan perlakuan meliputi perendaman pucuk daun di dalam air dingin selama 3 jam, fiksasi dalam larutan Carnoy selama ±24 jam, dan hidrolisis dalam larutan HCl 5N selama 30 menit. Hasil penelitian menunjukkan nilai IM tertinggi meristem pucuk daun H. rosa-sinensis variasi single pink besar muncul pada pukul 10:00 sebesar 94%. Berdasarkan hasil tersebut dapat disimpulkan bahwa waktu sampling yang optimal untuk analisis kromosom H. rosa-sinensis L. variasi single pink besar adalah pukul 10:00 dengan jumlah kromosom 2n= ca. 69-111. Hasil penelitian ini dapat dijadikan dasar untuk studi kromosom selanjutnya serta acuan untuk sampling variasi lainnya.Abstract Hibiscus rosa-sinensis L. is an ornamental plant that has many benefits and represents the character of polyploidy. The purpose of this study is to find out the Mitotic Index of leaf shoots Hibiscus rosa-sinensis on several shoots sampling times. The Mitotic Index and the timing of shoots sampling time are very necessary for chromosome studies because at this stage chromosomes characters can be clearly observed and easily calculated. Period time of collection the leaf shoots is from 08:00 AM to 16:00 PM, with two hours interval each at 08:00, 10:00, 12:00, 14:00, 16:00 . The chromosome preparation was carried out by using the squash method and aceto-orcein staining. The treatment steps included soaking the leaf shoots in cold water for 3 hours, fixation in Carnoy solution for ± 24 hours, and hydrolysis in 5N HCl solution for 30 minutes. The results showed that chromosomes were clearly visualized during the phase with the highest Mitotic Index. In addition, the percentage of Mitotic Index was found to be in line with the percentage of cells in late prophase. Among several sampling time variations, the highest Mitotic Index of Hibiscus rosa-sinensis leaf shoots appeared at 10:00 at 94% with the chromosome numbers of 2n= ca. 69-111. According to the data obtained, it is concluded that 10 AM is the most optimum sampling time that can be used as the basic information for further chromosome studies.

Basic approaches to simulation of resist mask formation in computational lithography

Main currently used resist mask formation models and problems solved have been overviewed. Stages of "full physical simulation" have been briefly analyzed based on physicochemical principles for conventional diazonapthoquinone (DNQ) photoresists and chemically enhanced ones. We have considered the concepts of the main currently used compact models predicting resist mask contours for full-scale product topologies, i.e., VT5 (Variable Threshold 5) and CM1 (Compact Model 1). Computation examples have been provided for full and compact resist mask formation models. Full resist mask formation simulation has allowed us to optimize the lithographic stack for a new process. Optimal thickness ratios have been found for the binary anti-reflecting layers used in water immersion lithography. VT5 compact model calibration has allowed us to solve the problem of optimal calibration structure sampling for maximal coverage of optical image parameters space while employing the minimal number of structures. This problem has been solved using cluster analysis. Clustering has been implemented using the k-means method. The optimum sampling is 300 to 350 structures, the rms error being 1.4 nm which is slightly greater than the process noise for 100 nm structures. The use of SEM contours for VT5 model calibration allows us to reduce the rms error to 1.18 nm for 40 structures.