Search results for "freezing"

Evaluation of Microbiological and Physico-Chemical Quality of Raw Milk from Sibiu Dairy Farm Province of Romania

2011

Research aims at benchmarking the quality of raw milk supplied by four private farms in the county of Sibiu at a distance of about 25 km each for a period of three months (April, May, June 2010). Samples were subject to particularly microbiological measurements (total number of germ and somatic cells), physico-chemical (acidity, fat density, non-fat dry matter, protein and freezing point titre) by international standard methods. The results of the four farms show different variations of the parameters analyzed as follows: 55.5% of the samples fall in physico-chemical parameters of standard quality and 79% of the samples fall within the parameters of microbiological quality standard and with…

Putrescine accumulation in Arabidopsis thaliana transgenic lines enhances tolerance to dehydration and freezing stress

2011

Polyamines have been globally associated to plant responses to abiotic stress. Particularly, putrescine has been related to a better response to cold and dehydration stresses. It is known that this polyamine is involved in cold tolerance, since Arabidopsis thaliana plants mutated in the key enzyme responsible for putrescine synthesis (arginine decarboxilase, ADC; EC 4.1.1.19) are more sensitive than the wild type to this stress. Although it is speculated that the over-expression of ADC genes may confer tolerance, this is hampered by pleiotropic effects arising from the constitutive expression of enzymes from the polyamine metabolism. Here, we present our work using A. thaliana transgenic pl…

In Vitro Bioavailability of Phenolic Compounds from Five Cultivars of Frozen Sweet Cherries (Prunus aviumL.)

2008

The bioavailability of phenolic compounds from five cultivars of frozen sweet cherries was assessed by a digestion process involving pepsin-HCl digestion (to simulate gastric digestion) and pancreatin digestion with bile salts (to simulate small intestine conditions) and dialyzed to assess serum- and colon-available fractions. After pepsin digestion, the % recovery of total phenolics, relative to the original starting material, increased, whereas the % anthocyanins did not change. Following pancreatic digestion and dialysis, the total phenolics in the IN (serum-available) fraction was about 26–30% and the OUT (colon-available) fraction was about 77–101%. The anthocyanin content in the IN fr…

Numerical Solution of Foodstuff Freezing Problems Using Radial Basis Functions

2013

This work presents a novel numerical approach for the solution of time dependent non-linear freezing processes in terms of radial basis function Hermite approach. The proposed scheme is applied to a mashed potato sample during its freezing; evaluation of time evolution of the temperature profile at the core of the sample is carried out. Food thermal properties are highly dependent on temperature and the mathematical problem becomes highly non-linear and therefore particularly difficult to solve. Incorporating a Kirchhoff transformation significantly reduces the non-linearity. The robustness of the scheme is tested by comparison with experimental results available in literature.

Acute electrocorticographic changes following localized cortical freezing in the cat. Preliminary report.

1968

Negative impact of freeze–thaw cycles on the survival of tardigrades

2023

Global warming effects in temperate and polar regions include higher average temperatures and a decrease in snow cover, which together lead to an increase in the number of freeze–thaw cycles (FTC). These changes could affect the fitness of both terrestrial and aquatic species. In this study, we tested how tardigrades, ubiquitous microscopic invertebrates, face FTC. Tardigrades are amongst the most resistant animals to unfavorable conditions, including long and deep freezing periods, and are an emerging model group for invertebrate ecology and evolution. We used 12 populations of tardigrades, representing different families within order Parachela, inhabiting different ecosystems (glaciers, s…

A relationship between tolerance to dehydration of rice cell lines and ability for ABA synthesis under stress

2005

Plant dehydration is commonly caused by some adverse environmental conditions such as salinity, drought and freezing. As the plant hormone abscisic acid (ABA) is involved in responses to water stress, we studied its putative relationship with the degree of tolerance to these abiotic stresses. For this purpose we used cell lines that had been established from mature embryos of rice (Oryza sativa L, cvs. Bahia and Bomba), and selected by their high (L-T) or low (L-S) levels of tolerance to each type of stress. Tolerance of rice calli to either osmotic, saline, or freezing stress was generally improved by a previous treatment with ABA. This ABA effect was evident in those callus lines with low…

Observation of time-invariant coherence in a nuclear magnetic resonance quantum simulator

2016

The ability to live in coherent superpositions is a signature trait of quantum systems and constitutes an irreplaceable resource for quantum-enhanced technologies. However, decoherence effects usually destroy quantum superpositions. It was recently predicted that, in a composite quantum system exposed to dephasing noise, quantum coherence in a transversal reference basis can stay protected for an indefinite time. This can occur for a class of quantum states independently of the measure used to quantify coherence, and it requires no control on the system during the dynamics. Here, such an invariant coherence phenomenon is observed experimentally in two different setups based on nuclear magne…

The subnivium, a haven for

2019

Parasite nematodes of the genus Trichinella are transmitted from one host to another through the ingestion of larvae present in striated muscles. The longer the survival of muscle larvae in host carcasses, the higher the probability of being ingested by a scavenging host. Thereby, these nematodes developed an anaerobic metabolism favouring their survival in decaying tissues. In addition, muscle larvae of three taxa, namely Trichinella nativa, Trichinella britovi and Trichinella T6, can survive freezing for several months to several years depending on the taxon. The aim of the present work was to investigate the survival time of T. britovi larvae in naturally infected host carcasses preserve…

Properties of new low melting point quaternary ammonium salts with bis(trifluoromethanesulfonyl)imide anion

2010

Eight new monocationic quaternary ammonium (QA) salts with the bis(trifluoromethanesulfonyl)imide (TFSI) anion were prepared by metathesis using our previously reported QA halides as precursors. New salts were characterized both in liquid and solid state using 1 H and 13 C NMR techniques, mass spectroscopy and elemental analysis together with X-ray diffraction and thermoanalytical methods. In addition, residual water content, viscosity and conductivity measurements were made for three of the roomtemperature ionic liquids (RTILs). The crystal structures of three compounds were determined by X-ray single crystal diffraction. Powder diffraction was used to study the crystallinity of the solid …