scholarly journals Evaluating the Assembly Dynamics in the Human Vaginal Microbiomes With Niche-Neutral Hybrid Modeling

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhanshan (Sam) Ma
Keyword(s):  
Hybrid Models ◽  
Integrated Analysis ◽  
Vaginal Microbiome ◽  
Test Results ◽  
Statistical Inferences ◽  
Hypothesis Model ◽  
The Difference ◽  
Stochastic Dispersal ◽  
Threshold Setting ◽  
Stochastic Forces

Using 2,733 longitudinal vaginal microbiome samples (representing local microbial communities) from 79 individuals (representing meta-communities) in the states of healthy, BV (bacterial vaginosis) and pregnancy, we assess and interpret the relative importance of stochastic forces (e.g., stochastic drifts in bacteria demography, and stochastic dispersal) vs. deterministic selection (e.g., host genome, and host physiology) in shaping the dynamics of human vaginal microbiome (HVM) diversity by an integrated analysis with multi-site neutral (MSN) and niche-neutral hybrid (NNH) modeling. It was found that, when the traditional “default” P-value = 0.05 was specified, the neutral drifts were predominant (≥50% metacommunities indistinguishable from the MSN prediction), while the niche differentiations were moderate (<20% from the NNH prediction). The study also analyzed two challenging uncertainties in testing the neutral and/or niche-neutral hybrid models, i.e., lack of full model specificity – non-unique fittings of same datasets to multiple models with potentially different mechanistic assumptions – and lack of definite rules for setting the P-value thresholds (also noted as Pt-value when referring to the threshold of P-value in this article) in testing null hypothesis (model). Indeed, the two uncertainties can be interdependent, which further complicates the statistical inferences. To deal with the uncertainties, the MSN/NNH test results under a series of P-values ranged from 0.05 to 0.95 were presented. Furthermore, the influence of P-value threshold-setting on the model specificity, and the effects of woman’s health status on the neutrality level of HVM were examined. It was found that with the increase of P-value threshold from 0.05 to 0.95, the overlap (non-unique) fitting of MSN and NNH decreased from 29.1 to 1.3%, whereas the specificity (uniquely fitted to data) of MSN model was kept between 55.7 and 82.3%. Also with the rising P-value threshold, the difference between healthy and BV groups become significant. These findings suggested that traditional single P-value threshold (such as the de facto standard P-value = 0.05) might be insufficient for testing the neutral and/or niche neutral hybrid models.

scholarly journals Influence of Tool Length and Profile Errors on the Inaccuracy of Cubic-Machining Test Results

2021 ◽  
Vol 5 (2) ◽  
pp. 51
Author(s):  
Zongze Li ◽  
Hiroki Ogata ◽  
Ryuta Sato ◽  
Keiichi Shirase ◽  
Shigehiko Sakamoto
Keyword(s):  
Machine Tools ◽  
Test Accuracy ◽  
Test Results ◽  
Machining Error ◽  
Tool Profile ◽  
Machining Test ◽  
The Difference ◽  
Side Error ◽  
Profile Errors ◽  
Five Axis

A cubic-machining test has been proposed to evaluate the geometric errors of rotary axes in five-axis machine tools using a 3 × 3 zone area in the same plane with different tool postures. However, as only the height deviation among the machining zones is detected by evaluating the test results, the machining test results are expected to be affected by some error parameters of tool sides, such as tool length and profile errors, and there is no research investigation on how the tool side error influences the cubic-machining test accuracy. In this study, machining inaccuracies caused by tool length and tool profile errors were investigated. The machining error caused by tool length error was formulated, and an intentional tool length error was introduced in the simulations and actual machining tests. As a result, the formulated and simulated influence of tool length error agreed with the actual machining results. Moreover, it was confirmed that the difference between the simulation result and the actual machining result can be explained by the influence of the tool profile error. This indicates that the accuracy of the cubic-machining test is directly affected by tool side errors.

scholarly journals Experimental Study of the Space–Time Effect of a Double-Pipe Frozen Curtain Formation with Different Groundwater Velocities

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3830
Author(s):  
Shicheng Sun ◽  
Chuanxin Rong ◽  
Hua Cheng ◽  
Bin Wang ◽  
Xiaogang Jiang ◽  
...  
Keyword(s):  
Freezing Temperature ◽  
Physical Model Test ◽  
Sand Layer ◽  
Test Results ◽  
Groundwater Velocity ◽  
Test Platform ◽  
The Difference ◽  
Freezing Test ◽  
Double Pipe ◽  
Thermal Physical Properties

Groundwater velocity has significant effects on the formation of a frozen curtain during freezing. In order to study the influence of the velocity on a frozen curtain, a large physical model test platform was established for double-pipe freezing. Based on this platform, freezing tests for different velocities were carried out. Quartz sand was selected as a similar material. The freezing temperature of the saturated sand layer was found by analyzing the results of the nuclear magnetic resonance (NMR). Based on the study of the thermal physical properties of the sand layer, the freezing test results were analyzed, and the results showed that the flow led to the differential development of the temperature between the upstream and downstream sections of the freezing pipes. Moreover, the larger the velocity, the greater the difference. The flow prolonged the overlapping time of the frozen curtains. Additionally, the flow slowed down the development of the frozen curtain area and the frozen curtain thickness. The larger the flow velocity, the greater the inhibition of the flow on the development of the frozen curtain. The test results can provide more references for the design and construction of freezing engineering with flowing groundwater.

Influence of Collagen Status on Microstructures of Porous Collagen/TCP Composites

2007 ◽  
Vol 330-332 ◽  
pp. 495-498
Author(s):  
Chao Zou ◽  
Wen Jian Weng ◽  
Xu Liang Deng ◽  
Kui Cheng ◽  
Pi Yi Du ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Cell Growth ◽  
Tricalcium Phosphate ◽  
Freeze Drying ◽  
Alkali Treatment ◽  
Test Results ◽  
Collagen Matrices ◽  
The Difference ◽  
Porous Composites ◽  
Better Than

Two starting collagens, sponge and floc collagen, were used to prepare collagen/tricalcium phosphate (TCP) composites. The resulting composites were porous and had 200μm pore size. However, there was a difference in the microstructure of the pore walls for the composites derived from the two collagens, the pore walls in sponge collagen/TCP composite were still porous and had 200 nm micropores size, TCP particles were trapped in collagen matrices. While floc collagen/TCP composite had smooth and dense walls in which TCP particles were embedded. The difference could be attributed to the starting collagen with different status. Sponge collagen has a soft structure, which easily becomes disassembled fibrils during alkali treatment, the disassembled fibrils are integrated again to form a dense morphology for pore walls after freeze-drying. While floc collagen has already a low disassembly degree, the alkali treatment could not be able to separate the fibrils, this remains as micropores in pore walls after freeze-drying. Both porous composites are significant in bone tissue engineering or regeneration. MTT test results showed the two composites had good cytocompatibility, and sponge collagen/TCP composite was somewhat better than floc collagen/TCP composite, which could result from that micropores derived roughness in pore walls of sponge collagen/TCP composite is suitable for cell growth.

Reply to comments of D. H. Zeuch

1992 ◽  
Vol 7 (7) ◽  
pp. 1959-1960
Author(s):  
Hu Gengxiang ◽  
Chen Shipu ◽  
Wu Xiaohua ◽  
Chen Xiaofu
Keyword(s):  
Compression Test ◽  
Compression Testing ◽  
Width Ratio ◽  
Test Results ◽  
Specimen Length ◽  
The Difference

Compression test results of our research on Al3Ti-base alloys are reported. It is evident that the specimen length-to-width ratio we used for compression testing can significantly reflect the difference in ductility of different alloys. Thus the tests fulfilled the aim of our present research.

Two important bridges protected from earthquake by extremely big sliding pendulum isolators

2021 ◽  
Author(s):  
Agostino Marioni ◽  
Roberto Dalpedri ◽  
Marco Banfi ◽  
Carla Cai
Keyword(s):  
Load Capacity ◽  
Special Focus ◽  
South East Asia ◽  
Vertical Load ◽  
Test Results ◽  
Surface Type ◽  
Total Length ◽  
Padma River ◽  
The Difference ◽  
Under Construction

<p>The Padma Bridge is a multipurpose road-rail bridge across the Padma River currently under construction in Bangladesh and is one of the most important projects in the whole south east Asia with a total length of 6150 m. The maximum design vertical load reaches 98725 kN.</p><p>The Holtekamp Bridge is a steel road bridge with 2 main spans of 150 m and 2 lateral spans of 75 for a total length of 450 m. The bridge is isolated by use of sliding pendulum isolators having a maximum vertical load capacity at ULS of 54915 kN.</p><p>In both cases the isolators are double sliding surface type but with a different approach about the central articulation. The paper aims to put in evidence the difference in behaviour of the 2 types of pendulum, analysing both the theoretical approach and the test results with a special focus over the adopted solution for perform the test on a device which exceed the capacity of aby existing laboratory.</p>

Moving to e-bidding

2019 ◽  
Vol 24 (1) ◽  
pp. 2-18 ◽  
Author(s):  
Djoen San Santoso ◽  
Nuttapon Bourpanus
Keyword(s):  
Wilcoxon Test ◽  
Test Results ◽  
Public Infrastructure ◽  
Senior Managers ◽  
Content Type ◽  
Thai Government ◽  
Infrastructure Project ◽  
The Difference ◽  
Public Money ◽  
Mean Differences

Purpose This study aims to examine the influences of shifting the bidding system of Thai public infrastructure projects from e-auction to e-bidding. Design/methodology/approach A questionnaire survey was conducted with owners or senior managers with direct responsibility in deciding the mark-up of 72 small and medium-sized contractor firms. Five senior professionals were interviewed to provide insights into and to strengthen the discussion of the findings. The Wilcoxon test was applied to analyze the difference in the importance of the factors between e-auction and e-bidding. Findings The results revealed a shift in the importance of the factors, from those related to the financial aspects in the e-auction to the situational aspects in the e-bidding. The comparison test results also suggested that the majority of factors become significantly less important in the e-bidding system, with “identity of competitors” and “general expense of the bidding process” having the most apparent mean differences. The interview results supported by data on winning prices and estimations strongly indicated that bid collusions likely exist in the e-auction. By shifting to e-bidding, the data also show that the Thai Government can save public money in its infrastructure project development. Originality/value The study provides an analysis from the perspectives of contractor firms on how e-auction and e-bidding options influence bid mark-up decisions. Many studies have focused on the issues and advantages provided by the e-procurement mainly from the owner (government)’s perspective but how the change influences the contractor’s attitude has been less explored.

Uncertainty and Inference for Verification Measures

2007 ◽  
Vol 22 (3) ◽  
pp. 637-650 ◽  
Author(s):  
Ian T. Jolliffe
Keyword(s):  
Hypothesis Testing ◽  
Confidence Intervals ◽  
Multiple Testing ◽  
Prediction Intervals ◽  
Hypothesis Tests ◽  
Statistical Inferences ◽  
The Difference ◽  
Main Ideas

Abstract When a forecast is assessed, a single value for a verification measure is often quoted. This is of limited use, as it needs to be complemented by some idea of the uncertainty associated with the value. If this uncertainty can be quantified, it is then possible to make statistical inferences based on the value observed. There are two main types of inference: confidence intervals can be constructed for an underlying “population” value of the measure, or hypotheses can be tested regarding the underlying value. This paper will review the main ideas of confidence intervals and hypothesis tests, together with the less well known “prediction intervals,” concentrating on aspects that are often poorly understood. Comparisons will be made between different methods of constructing confidence intervals—exact, asymptotic, bootstrap, and Bayesian—and the difference between prediction intervals and confidence intervals will be explained. For hypothesis testing, multiple testing will be briefly discussed, together with connections between hypothesis testing, prediction intervals, and confidence intervals.

scholarly journals In-situ Desaturation Tests by Electrolysis for Liquefaction Mitigation

2021 ◽  
Author(s):  
Runze Chen ◽  
Yumin Chen ◽  
Hanlong Liu ◽  
Kunxian Zhang ◽  
Ying Zhou ◽  
...  
Keyword(s):  
Minimum Degree ◽  
Electricity Consumption ◽  
Potential Method ◽  
Economic Benefits ◽  
Degree Of Saturation ◽  
Test Results ◽  
Liquefaction Resistance ◽  
The Difference ◽  
Maximum And Minimum Degree

Electrolytic desaturation is a potential method for improving the liquefaction resistance of the liquefiable foundation by reducing the soil saturation. In this study, in-situ desaturation tests were performed to investigate the resistivity of soil at different depth and the water level of the foundation under different current. The test results show that at constant currents of 1 A (Ampere, unit of the direct current), 2 A and 3 A, the saturation of the treated foundation reached 87%, 83% and 80%. During the electrolysis process, the generated gas migrates vertically and horizontally under the influence of buoyancy and gas pressure. In the end of electrolysis, the gas inside the sand foundation basically migrates vertically only. The higher current intensity employed for electrolysis will affect the uniformity and stability of the gas. At constant currents of 1 A, 2 A and 3 A, the difference between the maximum and minimum degree of saturation in the treated foundation was 14%, 18% and 19%; and after electrolysis halted for 144 h, the saturation in the treated foundation was 90%, 85% and 87%. The electricity consumption analysis indicates that the desaturation method has excellent economic benefits in the treatment of saturated sand foundations.

scholarly journals Metode Tutor Sebaya Berbantuan Whatsapp untuk Meningkatkan Hasil Uji Coba Ujian Nasional di SMK Negeri 1 Tanjungpandan

2019 ◽  
Vol 6 (2) ◽  
pp. 691-703
Author(s):  
Yuli Yulianti
Keyword(s):  
Peer Tutoring ◽  
Average Score ◽  
Learning Method ◽  
Test Results ◽  
Peer Tutors ◽  
National Examination ◽  
The Subject ◽  
The Difference ◽  
The Government ◽  
Academic Year

National Examination is one of the learning results assessment set by the Government, and is ruled at Minister of Education and Culture regulation Number 4 year 2018. The problem discussed in this study is the low percentage of students achieving Graduare Competence Standard/SKL 55 in the nationale examination tryout for mathematics. One of the alternatives to solve this problem is the Peer Tutoring learning method using Whatsapp Messenger application asisstance, in which the subject is grade 12 AP students of SMK Negeri 1 Tanjungpandan academic year of 2018/2019. The research method implemented is the classroom action research. The peer tutoring learning method using Whatsapp Messenger application asisstance was carried out both inside and outside the classroom by providing a smaller member whatsapp group and a  classroom whatsapp group. Each small group consists of 6 people in which there were 1-2 peer tutors. Based on the results of data analysis and discussion, there was an increase at the results of the tryout of mathematics national exam tryout for grade 12 AP students after peer tutoring learning method using whatsapp messenger application asisstance was applied, with the total increase up to 50%. This fact can be inferred from the difference of the test results percentage for the first tryout and the third tryout which is from 10% to 60%, while the average score is increased from 34.96 to 60.22 by 25.26 points.

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