84 research outputs found
Comparing of retention of cast crowns cemented with two kind of permanent cement with and without prier use of temporary cement
Introduction: This study evaluated the effects of eugenol –free temporary cement remnants on the
retentive strength of casting crowns luted via zinc phosphate and resin cement (Maxcem) to the
tooth structure.
Material and methods: 40 extracted human molars ware randomly divided into 2 groups. each
group was then divided into 2 subgroups and the teeth were paired so that the size of each tooth in
each subgroup was the same as a tooth in the other subgroups. 40 standardized Ni-cr complete
crowns were made on teeth prepared with a milling machine using conventional laboratory
techniques. For each adhesive system, in one subgroups a provisional restoration was cemented
using an eugenol –free temporary cement. Temporary crown was remained on the tooth structure
for an hour and then extracted and cement remnant was removed by an excavator. Then the casing
crowns were adhesively luted via zinc phosphate, adhesive resin(Maxcem) to prepared teeth. After
24h storage in distilled water, Retention was evaluated by measuring the tensile force required to
dislodge the crowns from tooth preparations with a universal testing machine after thermo cycling
(1500 cycles between 5c and 55c with 1- minute dwell times). The data were analyzed by means of
paired T-test and wilcoxon test in SPSS software version 11.5
Results: The analysis showed the mean retentive strength for 2 subgroups with and without prior
use of temporary cement in the maxcem group was 176 ± 55 and 274 ± 169 N, there was not a
significant difference between the 2 subgroups. (p value = 0.174). And the mean retentive strength
for 2 subgroups with and without prior use of temporary cement in the zincphosphate group was
257 ± 125 and 238 ± 135 N, there was not significan t difference between the 2 subgroups (p value
= 0.782).
Discussion: The use of an eugenol –free temporary cement does not alter the retentive strength of
casting restorations lutted to prepared teeth using the tested adhesive system, when temporary
cements are removed properly
Exploring the potential of machine learning methods and selection signature analyses for the estimation of genomic breeding values, the estimation of SNP effects and the identification of possible candidate genes in dairy cattle
The objective of this thesis was to study a variety of factors that affect the accuracy of genomic predictions applying random forest methodology (RF), genomic BLUP (GBLUP) and single step genomic BLUP (ssGBLUP) method with strong focus on training set design. In the following, selection signature through variation in linkage disequilibrium (LD) within and between dual-purpose black and white (DSN) and Holstein populations was identified.
In chapter 2 a stochastic simulation was applied for genomic predictions of binary disease traits based on cow training set. Composition of training and testing sets were modified in different allocating schemes. In addition, different scenarios were studied according to the quantitative-genetic background of the trait, the genetic architecture as well as low and high density of SNP chip panel. The highest genomic prediction accuracies were achieved when disease incidences within training sets was close to the population disease incidence of 0.20. Decreasing the traits heritability and QTL reduction were associated with decreasing genomic prediction accuracies.In chapter 3, different disease traits from 6,744 cows with genotypes from 58 large-scale contract herds was used to study the impact of training set composition, the impact of response variable as well as the impact of RF, GBLUP and ssGBLUP methodology on genomic prediction accuracies. Using de-regressed proofs (DRP) as response variables, accuracies were larger compared to pre-corrected phenotypes (PCP) for both methods GBLUP and RF. A further increase in genomic prediction accuracies was realized via ssGBLUP method compared to corresponding scenarios with RF or GBLUB. In addition, RF identified significant SNP close to potential positional candidate gene, i.e., GAS1, GPAT3, and CYP2R1 for clinical mastitis, SPINK5 and SLC26A2 for laminitis, and FGF12 for infertility.Genetic variation between the Holstein and the DSN population as well as between sub-populations was inferred by using XP-EHH method in chapter 4. The analysis was performed on 2,076 genotyped Holstein cows and 261 genotyped DSN cows. The most outstanding XP-EHH score that revealed the regions under recent selection was on chromosome 6 and on chromosome 12 for DSN and on chromosome 20 for Holstein population. Annotation of selection signature regions revealed various genes associated with production traits such as CLU and WARS2. Furthermore, several hub genes associated with dermatitis digitalis resistance was detected including FARS2, ACTR8 and CRY1.Ziel dieser Arbeit war die Analyse einer Vielzahl von Faktoren, welche die Genauigkeit der genomischen Zuchtwertschätzung beeinflussen. Hierzu wurden, mit besonderer Fokussierung auf die Konzeption der Referenzstichprobe, Random Forest (RF), genomic BLUP (GBLUP) und single step genomic BLUP (ssGBLUP) Verfahren angewendet. Nachfolgend wurden Selektionssignaturen mithilfe von Variationen im Kopplungsungleichgewicht (LD) innerhalb und zwischen Populationen des Schwarzbunten Niederungs- und Holsteinrinds identifiziert. Im zweiten Kapitel wurde eine stochastische Simulation appliziert, um genomische Schätzungen binärer Krankheitsmerkmale basierend auf der Referenzstichprobe durchzuführen. Die Struktur der Referenz- und Teststichprobe wurde in verschiedenen Zuweisungsschemata modifiziert. Darüber hinaus fand die Anwendung divergenter Szenarien hinsichtlich des quantitativ-genetischen Hintergrundes, der genetischen Architektur sowie der Dichte des SNP Chip statt. Die höchste genomische Schätzgenauigkeit wurde bei Annäherung der Krankheitsinzidenz innerhalb der Referenzstichprobe an die Inzidenz der Population von 0,20 erreicht. Die Reduktion der Merkmalsheritabilität und QTL ging mit einer Verringerung der genomischen Schätzgenauigkeit einher. In Kapitel drei wurde der Effekt der Struktur der Referenzstichprobe, der abhängigen Variablen wie auch der RF, GBLUP und ssGBLUP Methode auf die genomische Schätzgenauigkeit, unter Einbeziehung diverser Krankheitsmerkmale von 6744 genotypisierten Kühen aus 58 Testherden, analysiert. Die Verwendung deregressierter Zuchtwerte (DRP) als abhängige Variable im GBLUP sowie RF Verfahren, führte zu einer Verbesserung der Genauigkeiten im Vergleich zur Nutzung vorkorrigierter Phänotypen (PCP). Ein weiterer Anstieg der Genauigkeit wurde durch Anwendung der ssGBLUP Methode erzielt. Mithilfe der RF Methode, konnten zudem signifikante SNP in der Nähe möglicher Kandidatengene wie GAS1, GPAT3, CYP2R1 für Mastitis, SPINK5, SLC26A2 für Laminitis und FGF12 für Unfruchtbarkeit identifiziert werden. Genetische Variation zwischen der Holstein und DSN Population wie auch Subpopulationen wurde mithilfe der XP-EHH Methode, unter Einbeziehung von 2076 genotypisierten Holstein und 261 DSN Kühen, in Kapitel vier dargestellt. Der auffälligste XP-EHH Score, jüngste Selektionsregionen darstellend, wurde auf Chromosom 6 und 12 für DSN und auf Chromosom 20 für die Holsteinpopulation detektiert. Die Annotation der Selektionssignaturregionen eruierte diverse, mit Produktionsmerkmalen assoziierte Gene wie CLU und WARS2, wie auch einige, mit Dermatitis Digitalis Resistenz assoziierte Hub Gene, einschließlich FARS2, ACTR8 und CRY1
Seasonal heavy metal monitoring of water, sediment and common carp (Cyprinus carpio) in Aras Dam Lake of Iran
Heavy metal in aquatic ecosystems are monitored by measuring their concentrations in water, sediments and biota. In the presented study, cadmium, copper, lead, mercury, nickel, and zinc concentrations determined in water, sediment and tissues (liver and muscle) of Cyprinus carpio in Aras dam Lake of Iran, during spring, summer, autumn, and winter from 2016 to 2017. The concentration of Pb, Cd, Zn, Cu and Ni of samples were measured using inductively coupled plasma-optical emission spectroscopy. The concentration of Hg was analyzed using Atomic Absorption equipped with MHS 15 CVAAS. The trend in the metal mean concentrations of liver and muscle was Zn>Cu>Pb≈Ni>Cd>Hg, and water and sediment were Cu>Zn>Pb>Cd≈Ni>Hg. Heavy metals concentration was more in sediment than fish tissues and water. This results revealed that heavy metals accumulation of muscle was the highest in summer showing the most contaminated season. Whereas, winter had the lowest contamination in water (Cd،Hg, Cu, Pb, Ni, Zn), sediments (Hg, Cu, Zn, Pb, Ni), and the liver and muscle of fish (Cd, Zn, Ni, Cu). The amount of heavy metals was less or slightly higher than global standards (EPA, WHO).
An optimized direct control method applied to multilevel inverter for microgrid power quality enhancement
Multifunctional DGs and active power filters have become a mature technology in recent years, so in this paper, an optimized current control method for a multilevel converter is proposed. The control method will overcome harmonic current tracking inefficiency of previous control methods in online harmonic compensation applications in microgrids. This control method is applicable for grid-connected inverter-based multi-functional Distributed Generation (DG) converters. It could also be used in active power filter applications which need high-speed reference tracking ability. Having the advantages of current control methods like hysteresis band control, proportional-integral (PI) and proportional-resonant (PR) control methods, the proposed approach overcomes disadvantages of these methods especially in harmonic reference tracking as it will be discussed in detail. The main advantages of this method are the simplicity of implementation, calculation delay compensation and its fast response to changes. The power electronic circuit, operating principles, two-horizon predicted switching states of multilevel inverter, experimental results and applications of this control method will be discussed in the paper. For studying the feasibility of the control method, an experimental prototype is tested in a microgrid platform
Gene-Set Enrichment Analysis for Identifying Genes and Biological Activities Associated with Growth Traits in Dromedaries
Simple Summary This project aimed to find biological themes affecting growth in dromedaries. Candidate SNPs associated with growth were mapped to 22 genes, and 25 significant themes were identified related to growth. The main biological functions included calcium ion binding, protein binding, DNA-binding transcription factor activity, protein kinase activity, tropomyosin binding, myosin complex, actin-binding, ATP binding, receptor signaling pathway via JAK-STAT, and cytokine activity. EFCAB5, MTIF2, MYO3A, TBX15, IFNL3, PREX1, and TMOD3 genes are candidates for improving growth in camel breeding programs. Growth is an important heritable economic trait for dromedaries and necessary for planning a successful breeding program. Until now, genome-wide association studies (GWAS) and QTL-mapping have identified significant single nucleotide polymorphisms (SNPs) associated with growth in domestic animals, but in dromedaries, the number of studies is very low. This project aimed to find biological themes affecting growth in dromedaries. In the first step, 99 candidate SNPs were chosen from a previously established set of SNPs associated with body weight, gain, and birth weight in Iranian dromedaries. Next, 0.5 kb upstream and downstream of each candidate SNP were selected from NCBI (assembly accession: GCA_000803125.3). The annotation of fragments with candidate SNPs regarding the reference genome was retrieved using the Blast2GO tool. Candidate SNPs associated with growth were mapped to 22 genes, and 25 significant biological themes were identified to be related to growth in dromedaries. The main biological functions included calcium ion binding, protein binding, DNA-binding transcription factor activity, protein kinase activity, tropomyosin binding, myosin complex, actin-binding, ATP binding, receptor signaling pathway via JAK-STAT, and cytokine activity. EFCAB5, MTIF2, MYO3A, TBX15, IFNL3, PREX1, and TMOD3 genes are candidates for improving growth in camel breeding programs
Genome-wide association analyses of carcass traits using copy number variants and raw intensity values of single nucleotide polymorphisms in cattle
peer-reviewedBackground
The carcass value of cattle is a function of carcass weight and quality. Given the economic importance of carcass merit to producers, it is routinely included in beef breeding objectives. A detailed understanding of the genetic variants that contribute to carcass merit is useful to maximize the efficiency of breeding for improved carcass merit. The objectives of the present study were two-fold: firstly, to perform genome-wide association analyses of carcass weight, carcass conformation, and carcass fat using copy number variant (CNV) data in a population of 923 Holstein-Friesian, 945 Charolais, and 974 Limousin bulls; and secondly to perform separate association analyses of carcass traits on the same population of cattle using the Log R ratio (LRR) values of 712,555 single nucleotide polymorphisms (SNPs). The LRR value of a SNP is a measure of the signal intensity of the SNP generated during the genotyping process.
Results
A total of 13,969, 3,954, and 2,805 detected CNVs were tested for association with the three carcass traits for the Holstein-Friesian, Charolais, and Limousin, respectively. The copy number of 16 CNVs and the LRR of 34 SNPs were associated with at least one of the three carcass traits in at least one of the three cattle breeds. With the exception of three SNPs, none of the quantitative trait loci detected in the CNV association analyses or the SNP LRR association analyses were also detected using traditional association analyses based on SNP allele counts. Many of the CNVs and SNPs associated with the carcass traits were located near genes related to the structure and function of the spliceosome and the ribosome; in particular, U6 which encodes a spliceosomal subunit and 5S rRNA which encodes a ribosomal subunit.
Conclusions
The present study demonstrates that CNV data and SNP LRR data can be used to detect genomic regions associated with carcass traits in cattle providing information on quantitative trait loci over and above those detected using just SNP allele counts, as is the approach typically employed in genome-wide association analyses
A critical review of the current progress of plastic waste recycling technology in structural materials
One of the main environmentally threatening factors is plastic waste which generates in great quantity and causes severe damage to both inhabitants and the environment. Commonly, plastic waste generated on the land ends up in water bodies, resulting in detrimental solid impacts on the aquatics via poisoning and flooding the marine ecosystem. Exploring various approaches to convert plastic wastes into new products known as an efficient way to manage them and to enhance the sustainability of the environment, discussed in this article. Moreover, The limitation of the application of plastic waste for construction purposes is also considered. It is wind up that the usage of plastic waste for construction purposes will significantly rectify the sustainability of our environment and also be regarded as a trustworthy source of materials for applying in conventional materials such as concrete and asphalt
The Contribution of Copy Number Variants and Single Nucleotide Polymorphisms to the Additive Genetic Variance of Carcass Traits in Cattle
The relative contributions of both copy number variants (CNVs) and single nucleotide polymorphisms (SNPs) to the additive genetic variance of carcass traits in cattle is not well understood. A detailed understanding of the relative importance of CNVs in cattle may have implications for study design of both genomic predictions and genome-wide
association studies. The first objective of the present study was to quantify the relative contributions of CNV data and SNP genotype data to the additive genetic variance of
carcass weight, fat, and conformation for 945 Charolais, 923 Holstein-Friesian, and 974 Limousin sires. The second objective was to jointly consider SNP and CNV data in a least absolute selection and shrinkage operator (LASSO) regression model to identify genomic regions associated with carcass weight, fat, and conformation within each of the three breeds separately. A genomic relationship matrix (GRM) based on just CNV data did not capture any variance in the three carcass traits when jointly evaluated with a SNP-derived GRM. In the LASSO regression analysis, a total of 987 SNPs and 18 CNVs were associated with at least one of the three carcass traits in at least one of the three
breeds. The quantitative trait loci (QTLs) corresponding to the associated SNPs and CNVs overlapped with several candidate genes including previously reported candidate
genes such as MSTN and RSAD2, and several potential novel candidate genes such as ACTN2 and THOC1. The results of the LASSO regression analysis demonstrated that CNVs can be used to detect associations with carcass traits which were not detected using the set of SNPs available in the present study. Therefore, the CNVs and SNPs available in the present study were not redundant forms of genomic data
Investigation of water vapour sorption mechanism of starch-based pharmaceutical excipients
Starch-based excipients are commonly used in oral solid dosage forms. The effect of particle size and pregelatinisation level of starch-based excipients on their water absorption behaviour have been evaluated. The results showed that starch-based excipients have type ii isotherms, indicating that the principal mechanism of sorption is the formation of monolayer coverage and multilayer water molecules (10–80 RH %). It was found that the particle size of starch-based excipients did not have any influence on the rate of water sorption, whereas the level of pregelatinisation changed the kinetics of water sorption-desorption. Results showed that the higher the degree of pregelatinisation, the higher the rate of water absorption, which is irrespective of particle size. SEM images showed that a partially gelatinised starch had a firm granular structure with small pores and channels on the surface while a fully gelatinised starch had more irregular and spongy like surface with a degree of fractured particles
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