Nutritional components as mitigators of cellular senescence in organismal aging: a comprehensive review

Food Science and Biotechnology - The process of cellular senescence is rapidly emerging as a modulator of organismal aging and disease. Targeting the development and removal of senescent cells is...     

Heifers with positive genetic merit for fertility traits reach puberty earlier and have a greater pregnancy rate than heifers with negative genetic merit for fertility traits

This study investigated the hypothesis that dairy heifers divergent in genetic merit for fertility traits differ in the age of puberty and reproductive performance. New Zealand's fertility breeding value (FertBV) is the proportion of a sire's daughters expected to calve in the first 42 d of the seasonal calving period. We used the New Zealand national dairy database to identify and select Holstein-Friesian dams with either positive (POS, +5 FertBV, n = 1,334) or negative FertBV (NEG, ?5% FertBV, n = 1,662) for insemination with semen from POS or NEG FertBV sires, respectively. The resulting POS and NEG heifers were predicted to have a difference in average FertBV of 10 percentage points. We enrolled 640 heifer calves (POS, n = 324; NEG, n = 316) at 9 d ± 5.4 d (± standard deviation; SD) for the POS calves and 8 d ± 4.4 d old for the NEG calves. Of these, 275 POS and 248 NEG heifers were DNA parent verified and retained for further study. The average FertBV was +5.0% (SD = 0.74) and ?5.1% (SD = 1.36) for POS and NEG groups, respectively. Heifers were reared at 2 successive facilities as follows: (1) calf rearing (enrollment to ～13 wk of age) and (2) grazier, after 13 wk until 22 mo of age. All heifers wore a collar with an activity sensor to monitor estrus events starting at 8 mo of age, and we collected weekly blood samples when individual heifers reached 190 kg of body weight (BW) to measure plasma progesterone concentrations. Puberty was characterized by plasma progesterone concentrations >1 ng/mL in at least 2 of 3 successive weeks. Date of puberty was defined when the first of these samples was >1 ng/mL. Heifers were seasonally bred for 98 d starting at ～14 mo of age. Transrectal ultrasound was used to confirm pregnancy and combined with activity data to estimate breeding and pregnancy dates. We measured BW every 2 wk, and body condition and stature at 6, 9, 12, and 15 mo of age. The significant FertBV by day interaction for BW was such that the NEG heifers had increasingly greater BW with age. This difference was mirrored with the significant FertBV by month interaction for average daily gain, with the NEG heifers having a greater average daily gain between 9 and 18 mo of age. There was no difference in heifer stature between the POS and NEG heifers. The POS heifers were younger and lighter at puberty, and were at a lesser mature BW, compared with the NEG heifers. As a result, 94 ± 1.6% of the POS and 82 ± 3.2% of the NEG heifers had reached puberty at the start of breeding. The POS heifers were 20% and 11% more likely to be pregnant after 21 d and 42 d of breeding than NEG heifers (relative risk = 1.20, 95% confidence interval of 1.03–1.34; relative risk = 1.11, 95% confidence interval of 1.01–1.16). Results from this experiment support an association between extremes in genetic merit for fertility base on cow traits and heifer reproduction. Our results indicate that heifer puberty and pregnancy rates are affected by genetic merit for fertility traits, and these may be useful phenotypes for genetic selection.     

Use of solution crystallization analysis by laser light scattering for studying the solution crystallization of various Ziegler–Natta‐catalysed polypropylenes

Solution crystallization analysis by laser light scattering (SCALLS) involves the observation of the scattering of diode mercury laser lamp light after it passes through a polymer solution. An increase in turbidity occurs when the hot polymer solution is cooled and the polymer starts to crystallize out of solution. This causes a decrease in the amount of laser light that can pass through the solution and an increase in the amount of scattered light. The reverse of this process leads to the turbidity decreasing with an increase in temperature. According to this concept, it is possible to follow the solution crystallization of various polypropylenes under controlled cooling. In this study, SCALLS was able to differentiate between different isotactic and syndiotactic polypropylenes with similar chemical structures, but different tacticity and molecular weights. Furthermore, SCALLS provided good crystallization information that is similar to that from crystallization analysis fractionation and temperature rising elution fractionation. In addition, SCALLS can be used as a quantitative tool for the measurement of weight fractions during dissolution. © 2014 Society of Chemical Industry     

Estimation of the Stress-Strength Reliability for Exponentiated Pareto Distribution Using Median and Ranked Set Sampling Methods

In reliability analysis, the stress-strength model is often used to describe the life of a component which has a random strength (X) and is subjected to a random stress (Y). In this paper, we considered the problem of estimating the reliability R=P [Y<X] when the distributions of both stress and strength are independent and follow exponentiated Pareto distribution. The maximum likelihood estimator of the stress strength reliability is calculated under simple random sample, ranked set sampling and median ranked set sampling methods. Four different reliability estimators under median ranked set sampling are derived. Two estimators are obtained when both strength and stress have an odd or an even set size. The two other estimators are obtained when the strength has an odd size and the stress has an even set size and vice versa. The performances of the suggested estimators are compared with their competitors under simple random sample via a simulation study. The simulation study revealed that the stress strength reliability estimates based on ranked set sampling and median ranked set sampling are more efficient than their competitors via simple random sample. In general, the stress strength reliability estimates based on median ranked set sampling are smaller than the corresponding estimates under ranked set sampling and simple random sample methods.     

Simultaneously achievement of high recoverable energy density and efficiency in sodium niobate-based ceramics

Journal of Materials Science: Materials in Electronics - Single lead-free Na0.73Bi0.09(Nb1???xTax)O3 (x?=?0, 0.10, 0.20, 0.30, and 0.40) ceramic phases were processed...     

Experimental investigation of a cook-off temperature in a hot barrel

The experimental investigations of the effect of contact time/temperature on initiating the cook-off using 7.62 mm calibre cartridge cases （CC） were conducted previously. These cartridges were filled with commercial off-the-shelf （COTS） double based （DB） propellant （Bulls Eye） and were loaded in a hot chamber. The thermal explosion temperature is of great significance to both weapon designers and safety inspectors as it provides the operational limit and safe operating temperature. For CC under test, it was found that the cook-off temperatures of this propellant were encountered with the heat transfer profile of the simulated gun barrel between 151.4 ℃ and 153.4 ℃, with a reaction occurring in less than 300 s after the round was chambered. Usefully, each experiment was found to be consistent and repeatable.     

Investigation of non-Newtonian flow characterization and rheology of heavy crude oil

The heavy crude oil exhibits a non-Newtonian shear thinning behavior over the examined shear rate. The viscosity of the heavy crude oil decreases about 15.6% when the temperature increased from 30 to 60°C. Heavy crude oil was blended with the aqueous solution of surfactant and saline water in different volumetric proportions of NaCl, and Na₂CO₃ solution mixtures. The addition of 50% of the mixture to the heavy crude oil causes a strong reduction in the viscosity, about 67.5% at 60°C. The heavy crude oil fits the Power law model since it has the lowest average absolute percent error of 0.0291. The flow behavior index of the heavy crude oil reaches a value of 0.9305 at a temperature of 30°C and it increases to 0.9373 when the temperature raises 60°C, while the consistence coefficient decreases from 2.8811 to 2.3558.     

In Vitro Antiamoebic Activity Evaluation and Docking Studies of Metronidazole–Triazole Hybrids

An in‐house database of 520 compounds was docked against Entamoeba histolytica thioredoxin reductase (EhTrR), a promising target for the treatment of amoebiasis. Amongst these, some metronidazole (MTZ)–triazole hybrids were ranked high, with docking scores from ?10.23 to ?7.56. Studies of the binding orientations and conformations show that the head groups of MTZ–triazole hybrids interact with the arginine residues within the binding pocket of EhTrR, making it clear that such is the optimal and most reliable orientation for this class of compounds. The top‐ten MTZ–triazole hybrids were then selected for evaluation of their activity against the HM1:IMSS strain of amoeba. The most active compound, 2‐pyridyl‐(1,2,3‐triazolyl)metronidazole 10 , with an IC₅₀ value of 8.4 nM , was significantly more active than the standard drug MTZ alone. Docking studies revealed that compound 10 may act as an EhTrR inhibitor with activity in the nanomolar range and satisfactory ADME properties; it is a suitable candidate to be carried forward as a potential lead in the discovery of drugs to combat amoebiasis.     

Three‐dimensional computational comparison of mini pinned heat sinks using different nanofluids: Part one—the hydraulic‐thermal characteristics

The hydraulic‐thermal characteristics of 3D pinned heat sink designs have been numerically compared as the first part of a three‐part investigation. Five different pin geometries (circular, square, triangular, strip, and elliptic pins) and an unpinned heat sink with three types of nanofluids (Al₂O₃–H₂O, SiO₂–H₂O, and CuO–H₂O) are considered for laminar forced convection. The range of Reynolds number is from 100 to 1000, and volume fractions vary between 0% and 5%. The finite volume method is employed to solve the Navier–Stokes and energy equations by employing a SIMPLE algorithm for a computational solution. Three parameters are presented—the Nusselt number, the bottom temperature, and the hydrothermal performance of the heat sink with pressure drop data. The findings indicated that the overall hydrothermal performance of elliptic‐pinned (EP) heat sinks produces the most substantial value of 3.10 for pure water. For different nanofluids, the SiO₂–water nanofluids with EPs have the most significant hydrothermal performance. Also, this factor is enhanced with an increase in nanofluid concentration up to nearly 3.34 for 5% of SiO₂–water. Consequently, applying the elliptic‐pinned heat sinks is recommended with pure water for considering an increase in the pressure drop, with 5% of SiO₂–water nanofluids, regardless of an enlargement of pressure drop for heat‐dissipation applications.     

Non-linear diffusion of image noise with minimal iterativity

Non-linear diffusion (ND) is an iterative difference equation used in several image processing applications such as denoising, segmentation, or compression. The number of iterations required to achieve optimal processing can be very high, making ND not suitable for real-time requirements. In this paper, we study how to reduce complexity of ND so as to achieve minimal number of iterations for real-time image denoising. To do this, we first study the relations between parameters of the iterative equation: the number of iterations, the time step, and the edge strength. We then proceed by estimating the minimally required number of iterations to achieve effective denoising. Then, we relate the edge strength to the number of iterations, to noise, and to the image structure. The resulted minimal iterativity ND is very fast, while still achieves similar or better noise reduction compared to related ND work. This paper also shows how the proposed spatial filter is suitable for structure-sensitive object segmentation and temporal noise reduction.