472 research outputs found
Some physical properties of spinach (Spinacia oleracea L.) seed
The physical properties of spinach seed were evaluated as a function of moisture content. Average length, width and thickness were 4.03, 3.51 and 2.44 mm, respectively, at 11.93% dry basis (d.b). moisture content. In the moisture range from 11.93 to 21.52% d.b. studies on rewetted spinach seed showed that the thousand seed mass increased from 11.55 to 13.53 g, the projected area from 6.28 to 7.81 mm2, the sphericity from 0.807 to 0.821 and the terminal velocity from 6.10 to 6.58 m s-1. The static coefficient of friction of spinach seed increased linearly against surfaces of four structural materials, namely, rubber (0.341 to 0.470), wood (0.318 to 0.391), stainless steel (0.271 to 0.364) and galvanised iron (0.321 to 0.388) as the moisture content increased from 11.93 to 21.52% d.b. The bulk density decreased from 538.9 to 893.1 kg m-3, the true density from 893.1 to 784.6 kg m-3 and the porosity from 39.65 to 36.67% respectively, with an increase in moisture content from 11.93 to 21.52% d.b
Effects of moisture content on some physical properties of red pepper (Capsicum annuum L.) seed
The physical properties of red pepper seed were evaluated as a function of moisture content. The average length, width and thickness were 4.46, 3.66 and 0.79 mm, respectively, at 7.27% d.b. moisture content. In the moisture range of 7.27 to 20.69% dry basis (d.b.), studies on rewetted red pepper seed showed that the thousand seed mass increased from 7.97 to 8.89 g, the projected area from 8.40 to 9.09 mm2, the sphericity from 0.525 to 0.555 and the terminal velocity from 4.36 to 4.51 m s-1. The static coefficient of friction of red pepper seed increased linearly against surfaces of four structural materials, namely, rubber (0.394 to 0.477), aluminium (0.255 to 0.382), stainless steel (0.298 to 0.416) and galvanised iron (0.319 to 0.395) as the moisture content increased from 7.27 to 20.69% d.b. The bulk density decreased from 402.1 to 360.0 kg m-3, the true density from 795.2 to 746.3 kg m-3 and the porosity increased from 49.43 to 51.76%, respectively, with an increase in moisture content from 7.27 to 20.69% d.b
Comparative evaluation of shear bond strength of three flowable compomers on enamel of primary teeth: An in-vitro study
Background: The aim of the present study was to determine Shear bond strength (SBS) of different flowable compomers on the enamel surface of primary teeth. The null hypothesis to be tested was that none of the flowable compomer would differ significantly from the other two with respect to SBS. As a result, the tested materials that have the easiest application on child patient is preferred. Material and Methods: Sixty newly extracted non carious primary molars were selected. The buccal surface was cleaned and polished to obtain a flat enamel surface. The specimens were randomly divided into three groups of 20 teeth each, based on the flowable compomers applied, as follows: group I: Dyract Flow® (Dentsply, Konstanz, Germany); group II: Twinky Star Flow® (Voco, Cuxhaven, Germany); and group III: R&D Series Nova Compomer Flow® (Imicryl, Konya, Turkey). Results: SBS in group II (6.78± 0.45 MPa) were significantly lower than groups I and III (8.30 ± 0.29 and 8.43 ± 0.66 MPa, respectively) (P<.001). No significant difference was found between groups I and III (P<.05). Conclusions: Significant differences existed between the SBS of the groups. Therefore, the null hypothesis was rejected. Flowable compomers can provide adequate SBS with self-etching system at restoration of primary teeth. Thus, successful restorations in pediatric patients can be done in a practical way. © Medicina Oral S.L
Ubiquitin-based probes prepared by total synthesis to profile the activity of deubiquitinating enzymes
Epitope-tagged active-site-directed probes are widely used to visualize the activity of deubiquitinases (DUBs) in cell extracts, to investigate the specificity and potency of small-molecule DUB inhibitors, and to isolate and identify DUBs by mass spectrometry. With DUBs arising as novel potential drug targets, probes are required that can be produced in sufficient amounts and to meet the specific needs of a given experiment. The established method for the generation of DUB probes makes use of labor-intensive intein-based methods that have inherent limitations concerning the incorporation of unnatural amino acids and the amount of material that can be obtained. Here, we describe the total chemical synthesis of active-site-directed probes and their application to activity-based profiling and identification of functional DUBs. This synthetic methodology allowed the easy incorporation of desired tags for specific applications, for example, fluorescent reporters, handles for immunoprecipitation or affinity pull-down, and cleavable linkers. Additionally, the synthetic method can be scaled up to provide significant amounts of probe. Fluorescent ubiquitin probes allowed faster, in-gel detection of active DUBs, as compared to (immuno)blotting procedures. A biotinylated probe holding a photocleavable linker enabled the affinity pull-down and subsequent mild, photorelease of DUBs. Also, DUB activity levels were monitored in response to overexpression or knockdown, and to inhibition by small molecules. Furthermore, fluorescent probes revealed differential DUB activity profiles in a panel of lung and prostate cancer cells
The euler class of a subset complex
The subset complex Δ(G) of a finite group G is defined as the simplicial complex whose simplices are non-empty subsets of G. The oriented chain complex of Δ(G) gives a G-module extension of by , where is a copy of integers on which G acts via the sign representation of the regular representation. The extension class ζG ∈ ExtGG-1 (, ) of this extension is called the Ext class or the Euler class of the subset complex Δ (G). This class was first introduced by Reiner and Webb [The combinatorics of the bar resolution in group cohomology, J. Pure Appl. Algebra 190 (2004), 291-327] who also raised the following question: What are the finite groups for which ζG is non-zero?In this paper, we answer this question completely. We show that ζG is non-zero if and only if G is an elementary abelian p-group or G is isomorphic to /9, /4 × /4 or (/2)n × /4 for some integer n ≥ 0. We obtain this result by first showing that ζG is zero when G is a non-abelian group, then by calculating ζG for specific abelian groups. The key ingredient in the proof is an observation by Mandell which says that the Ext class of the subset complex Δ (G) is equal to the (twisted) Euler class of the augmentation module of the regular representation of G.We also give some applications of our results to group cohomology, to filtrations of modules and to the existence of Borsuk-Ulam type theorems. © 2008. Published by Oxford University Press. All rights reserved
Variation of mohair staple length across Angora goat fleeces : implications for animal selection and fleece evaluation
The present study aimed to determine how the average mohair staple length (SL) differences between nine sampling sites vary between sex and flock, to identify differences in SL variability between sampling sites as a result of between-animal and between-sire variability and to determine SL correlations between sampling sites in between-animal and between-sire variability. Australian Angora goats (n=301) from two farms in southern Australia were sampled at 12 and 18 months of age at nine sites (mid side, belly, brisket, hind flank, hip, hock, mid back, neck and shoulder). Staples were taken prior to shearing at skin level and stretched SL determined. For each shearing, differences in SL between sampling sites, how these differences were affected by farm, sex and sire, and the covariance between sites for sire and individual animal effects were investigated by restricted maximum likelihood (REML) analyses. The median mid-side SL at 12 and 18 months of age was 110 and 130 mm, respectively, but the actual range in mid-side SL was 65–165 mm. There was an anterior–posterior decline in SL with the hock being particularly short. There was no evidence that the between-site correlation of the sire effects differed from 1, indicating that genetic selection for SL at one site will be reflected in SL over the whole fleece. However, low heritabilities of SL at the hock, belly and brisket or at any site at 12 months of age were obtained. There was more variability between sites than between sires, but the between-animal variation was greater. The hip and mid-back sites can be recommended for within-flock (culling) and genetic selection for SL due to their low sampling variability, moderate heritability and ease of location. <br /
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