692 research outputs found
Effects of Heat and Iron Fractions on Lipid Oxidation in Meat.
Size exclusion (SE) and hydrophobic interaction (HIC) high performance liquid chromatography (HPLC) methods were developed for determining hemoglobin, myoglobin, and total pigments in beef and chicken. Hemoglobin and myoglobin in beef, but not in chicken, were separated by HIC with minimum detectable levels of 0.187 and 0.085 g/l, respectively. Determination of total pigment by SE-HPLC (minimum detection of 0.001 g/l) was more sensitive than with spectrophotometric assay. The effects of heat at 55\sp\circC, 70\sp\circC, 85\sp\circC, and 100\sp\circC on the distribution of iron in six fractions (water-soluble, water-insoluble, diffusate, hematin, total heme, and ferritin) in beef and chicken muscles were determined. Iron content decreased (p 0.05) in water-soluble fractions and increased (p 0.05) in water-insoluble fractions as temperature increased to 100\sp\circC. The content of heme iron was decreased more from 55\sp\circC to 85\sp\circC than from 27\sp\circC to 55\sp\circC or 85\sp\circC to 100\sp\circC. The increase in the amount of diffusate iron appeared to be less than the decreased amount of heme iron at each heating temperature level. As temperature increased, hematin iron content was increased (p 0.05) and ferritin iron content was decreased (p 0.05). More ferritin iron was decreased (p 0.05) at temperature of 70\sp\circC than at 55\sp\circC. The catalytic abilities of heat at 55\sp\circC, 70\sp\circC, 85\sp\circC, and 100\sp\circC and nine forms of iron (water-extractable iron, diffusate iron, non-diffusate iron, hematin, Hb, Mb, ferritin, FeCl\sb2 and FeCl\sb3) on lipid oxidation in water-extracted meat residues (WR) and solvent-extracted fat emulsion (FE) of beef and chicken muscles were studied. Heat and different forms of iron promoted lipid oxidation (p 0.05) in WR and FE for both species. The catalytic abilities of the same forms of iron were different in WR and FE. All forms of iron catalyzed lipid oxidation in WR, however, ferritin, FeCl\sb2, or FeCl\sb3 did not increase lipid oxidation in FE. Heme iron was the major catalyst of lipid oxidation in FE, while both heme iron and iron in the low molecular weight fractions (diffusate iron) had high catalytic activity for lipid oxidation in WR
Automated Refactoring of Nested-IF Formulae in Spreadsheets
Spreadsheets are the most popular end-user programming software, where
formulae act like programs and also have smells. One well recognized common
smell of spreadsheet formulae is nest-IF expressions, which have low
readability and high cognitive cost for users, and are error-prone during reuse
or maintenance. However, end users usually lack essential programming language
knowledge and skills to tackle or even realize the problem. The previous
research work has made very initial attempts in this aspect, while no effective
and automated approach is currently available.
This paper firstly proposes an AST-based automated approach to systematically
refactoring nest-IF formulae. The general idea is two-fold. First, we detect
and remove logic redundancy on the AST. Second, we identify higher-level
semantics that have been fragmented and scattered, and reassemble the syntax
using concise built-in functions. A comprehensive evaluation has been conducted
against a real-world spreadsheet corpus, which is collected in a leading IT
company for research purpose. The results with over 68,000 spreadsheets with 27
million nest-IF formulae reveal that our approach is able to relieve the smell
of over 99\% of nest-IF formulae. Over 50% of the refactorings have reduced
nesting levels of the nest-IFs by more than a half. In addition, a survey
involving 49 participants indicates that for most cases the participants prefer
the refactored formulae, and agree on that such automated refactoring approach
is necessary and helpful
Optimal parameter for the SOR-like iteration method for solving the system of absolute value equations
The SOR-like iteration method for solving the absolute value equations~(AVE)
of finding a vector such that with is investigated. The convergence conditions of the SOR-like iteration method
proposed by Ke and Ma ([{\em Appl. Math. Comput.}, 311:195--202, 2017]) are
revisited and a new proof is given, which exhibits some insights in determining
the convergent region and the optimal iteration parameter. Along this line, the
optimal parameter which minimizes with and the approximate optimal parameter which
minimizes are explored.
The optimal and approximate optimal parameters are iteration-independent and
the bigger value of is, the smaller convergent region of the iteration
parameter is. Numerical results are presented to demonstrate that the
SOR-like iteration method with the optimal parameter is superior to that with
the approximate optimal parameter proposed by Guo, Wu and Li ([{\em Appl. Math.
Lett.}, 97:107--113, 2019]). In some situation, the SOR-like itration method
with the optimal parameter performs better, in terms of CPU time, than the
generalized Newton method (Mangasarian, [{\em Optim. Lett.}, 3:101--108, 2009])
for solving the AVE.Comment: 23 pages, 7 figures, 7 table
Construction and Transformation of a Thermotoga-E. coli Shuttle Vector
Background: Thermotoga spp. are attractive candidates for producing biohydrogen, green chemicals, and thermostable enzymes. They may also serve as model systems for understanding life sustainability under hyperthermophilic conditions. A lack of genetic tools has hampered the investigation and application of these organisms. This study aims to develop a genetic transfer system for Thermotoga spp. Results: Methods for preparing and handling Thermotoga solid cultures under aerobic conditions were optimized. A plating efficiency of similar to 50% was achieved when the bacterial cells were embedded in 0.3% Gelrite. A Thermotoga-E. coli shuttle vector pDH10 was constructed using pRQ7, a cryptic mini-plasmid found in T. sp. RQ7. Plasmid pDH10 was introduced to T. maritima and T. sp. RQ7 by electroporation and liposome-mediated transformation. Transformants were isolated, and the transformed kanamycin resistance gene (kan) was detected from the plasmid DNA extracts of the recombinant strains by PCR and was confirmed by restriction digestions. The transformed DNA was stably maintained in both Thermotoga and E. coli even without the selective pressure. Conclusions: Thermotoga are transformable by multiple means. Recombinant Thermotoga strains have been isolated for the first time. A heterologous kan gene is functionally expressed and stably maintained in Thermotoga
Distillation of Gaussian Einstein-Podolsky-Rosen steering with noiseless linear amplification
Einstein-Podolsky-Rosen (EPR) steering is one of the most intriguing features
of quantum mechanics and an important resource for quantum communication. The
inevitable loss and noise in the quantum channel will lead to decrease of the
steerability and turn it from two-way to one-way. Despite an extensive research
on protecting entanglement from decoherence, it remains a challenge to protect
EPR steering due to its intrinsic difference from entanglement. Here, we
experimentally demonstrate the distillation of Gaussian EPR steering in lossy
and noisy environment using measurement-based noiseless linear amplification.
Our scheme recovers the two-way steerability from one-way in certain region of
loss and enhances EPR steering for both directions. We also show that the
distilled EPR steering allows to extract secret key in one-sided
device-independent quantum key distribution. Our work paves the way for quantum
communication exploiting EPR steering in practical quantum channels
Monobutyl phthalate induces the expression change of G-Protein-Coupled Receptor 30 in rat testicular Sertoli cells
The aim of the study was to explore whether G-Protein-Coupled Receptor 30 (GPR30) was expressed in rat testicular Sertoli cells and to assess the impact of monobutyl phthalate (MBP) on the expression of GPR30 in Sertoli cells. By using RT-PCR, Western-Blot and immunofluorescent microscopy, the expression of GPR30 in rat Sertoli cells was found at both gene and protein level. Cultures of Sertoli cells were exposed to MBP (10– –1000 mM) or a vehicle. The results indicated that the expression of GPR30 increased at gene and protein levels in Sertoli cells following administration of MBP even at a relatively low concentration. We suggest that changes of GPR30 expression may play an important role in the effects of the xenoestrogen MBP on Sertoli cell function. (Folia Histochemica et Cytobiologica 2013, Vol. 51, No. 1, 18–24
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