Effect Of Low-temperature Treatment Research Articles

Insight into the effect of low temperature treatment on trichome density and related differentially expressed genes in Chinese cabbage.

Trichome is important for help plant resist adversity and external damage. However, it often affects the appearance and taste of vegetables. In the present study, the trichome density of leaves from two Chinese cabbage cultivars with and without trichomes treated at low temperature are analyzed by biological microscope, and the differentially expressed genes related to trichomes formation were screened through transcriptome sequencing. The results showed that the number of leaves trichomes was reduced by 34.7% at low temperature compared with room temperature. A total of 661 differentially expression genes effecting trichomes formation were identified at the CT vs C, LCT vs LC, CT vs LCT. Several differentially expression genes from every comparison group were enriched in plant hormone signal transduction and amino acid biosynthesis pathway. Combined with the central genes obtained by WGCNA analysis, five candidate genes Bra029778, Bra026393, Bra030270, Bra037264 and Bra009655 were screened. qRT-PCR analysis verified that the gene expression differences were in line with the trend of transcriptome data. This study not only found possible new key genes and laid a foundation for revealing the molecular mechanism regulating the formation of trichome in Chinese cabbage, but also provided a new way to study plant surface trichomes.

Delayed effect of low rearing temperature on gonadal DNA methylation in juvenile barramundi (Lates calcarifer)

Sex differentiation in many gonochoristic fish is highly responsive to temperature treatment. In some species, exposure to high or low temperatures during primary gonadal development induces phenotypic reversal of an otherwise genetically encoded sex. These changes in sexual phenotype occur in the absence of changes in genotype and are often accompanied by epigenetic modifications, such as DNA methylation. It is unknown if sequentially hermaphroditic fish exhibit similar temperature sensitivity to what has been shown in gonochoristic species; however, sex-specific differences in DNA methylation have been observed. The barramundi (Lates calcarifer) is a protandrous (male-first) sequential hermaphrodite that exhibits sex-specific DNA methylation patterns. To examine the effect of temperature on DNA methylation and primary gonadal differentiation in a sequential hermaphrodite, sexually immature barramundi were exposed to high (34 °C), control (29 °C) low (24 °C) and fluctuating (25–33 °C) temperatures from 10 to 90 days post hatch, and then on-reared at 29 °C for 12 months. At 6 months and 12 months, individuals were sampled, and their gonads examined for evidence of changes in DNA methylation and/or gonadal differentiation. Male-specific DNA methylation patterns and advanced testis development were observed at 12 months but were absent at 6 months, suggesting that low temperature treatment had a delayed effect on the gonads of juvenile barramundi. Additionally, there was an initial, but not lasting, negative effect of low temperature treatment on fish length and weight, indicating that compensatory growth may have occurred. This research provides the first evidence for an effect of temperature on gonadal DNA methylation and primary sexual development in a sequential hermaphrodite. A refinement of treatment timing and intensity could lead to the development of a hormone-free method of sex control for this widely cultured species.

Effects of low-temperature treatment on the coals mechanical properties microscale and airborne dust formation

The effect of freezing-thawing on the mechanical properties of coals at the microscale, the character of their destruction during cyclic nanoindentation, and the release of airborne dust have been studied. For these purposes, three hard coals from the Apsatsky deposit, two hard coals from the Pechora coal basin, and two lignites from the Kangalassky deposit were studied. It has been established that low-temperature impacts lead to a decrease in the content of airborne dust for all the coals. It was revealed that after freezingthawing of coals, their strength decreases, however, the character of destruction under mechanical impacts do not change. The exception is the coal of the middle stage of metamorphism of the Pechora basin, selected from a pack potentially prone to coal and gas outbursts. For this coal, low-temperature effects lead to a change in the character of its destruction during cyclic nanoindentation. Namely, there was a switch from the local (in the zone of contact with the indenter) character of destruction of the initial coal to the bulk one (outside the zone of contact with the indenter) for coal after low-temperature treatment. To assess the coals propensity to form fine dust particles, an index characterizing the degree of compaction of coal matter during cyclic nanoindentation with increasing load was introduced. It has been established that this index is proportionally connected with the content of airborne dust in coals (with sizes of less than 10 microns). It is shown that the coals proneness to form airborne dust under low-temperature impacts does not depend on the stage of coal metamorphism. For bituminous coals of the Apsatsky deposit with similar metamorphism degree the propensity to form dust is different. Variations in the propensity to form dust in coals of the Pechora basin, which also have a similar metamorphism degree, are apparently due to the peculiarities of the vitrinite structure of these coals.This work was carried out with the financial support of the Russian Science Foundation (Grant No. 18-77-10052).

Effect of low-temperature treatment on bacterial cultivation in bacterial induced mineralization

Effect of low-temperature treatment on bacterial cultivation in bacterial induced mineralization

Effect of Low temperature treatment on dormancy release of Sedum aizoon L.

The dormant Sedum aizoon L.seedlings were treated with different days(1d, 3d, 5d and 7d) of low temperature (5°C), and restored to grow for 40d (25°C).The growth indexes, photosynthetic characteristics and carbohydrate metabolism indexes were measured to compare the dormancy relieving effects of the seedlings. The results showed that Sedum aizoon L. was physiologic dormancy, and the effect was the best when it was treated at 5°C for 5 days, and the dormancy was completely relieved.

Effects of low-temperature treatment on the activity of proteolytic enzymes in various flour types

This work was aimed at investigating effects of low-temperature processing on the activity of proteolytic enzymes in various flour types. This study allowed an improved understanding of the mechanisms that change biotechnological processes in semi-finished dough products during low-temperature storage. The study of the effect of long-term low-temperature exposure on the activity of proteolytic enzymes in various flour types showed that this parameter depends on the medium pH, as well as on the flour type. During low-temperature storage, the activity of acid proteases tend to decrease by, on average, 10% in both traditional and non-traditional types of flour used for baking. The activity of weakly acidic and weakly alkaline proteases under the influence of low temperatures during storage depends on the flour type. At pH = 5.5, an increase in the duration of low-temperature exposure leads to a decrease in the proteolytic activity of spelt, wheat and buckwheat flour by, on average, 20, 12.5, and 18%, respectively. Conversely, this parameter increases in rye and oat flour by 12 and 28%, respectively. Under the influence of freezing and during low-temperature storage, the activity of weakly alkaline proteases in all studied flour types increases by 15.9%, except for buckwheat, the proteolytic activity of which decreases by 1.5–2 times during storage. It was established that proteolytic enzymes of corn flour exhibit the greatest resistance to long-term storage in a frozen form. Knowledge of the effect of low-temperature processing on the activity of proteolytic enzymes is important for predicting the rheological properties of semi-finished dough products and structural-mechanical and organoleptic characteristics of finished products. In addition, this knowledge facilitates the development of recipes and technological parameters for producing new bakery products based on frozen semi-finished products from traditional and non-traditional flour types.

In Vitro Study of Effect of Low Temperature Treatment on Contraction of Colon and Rectum of Adult and Neonate Rats

In Vitro Study of Effect of Low Temperature Treatment on Contraction of Colon and Rectum of Adult and Neonate Rats

Effect of Low Temperature Treatment for Rice Seedling on Yield in Hokkaido

Effect of Low Temperature Treatment for Rice Seedling on Yield in Hokkaido

Effects of low-temperature treatment on the properties of commercial preceramic polymers

Low-temperature, pre-gelation, thermal treatment of ceramic precursors is a common preliminary step in the polymer infiltration-and-pyrolysis-based processing of ceramic matrix composites (CMCs). A variety of polymer properties can be modified using this approach, the most important being molecular weight distribution, viscoelastic state, solidification behavior, and ceramic yield. In this work, the effects of thermal treatment on the processing properties of two commercial preceramic polymers, StarPCS™ SMP-10 and KiON Ceraset® PSZ-20, have been investigated. It was determined that the volatilization, molecular chain scission, and polymerization phenomena occurring during treatment, lead to increased viscosity, higher molecular weight, lower temperature of solidification onset, and improved ceramic yield. A wide range of tailorable viscoelastic states was obtained, and allowed the formation of continuous polymer filaments. Understanding the nature and effect of these modifications on the processing state can improve the current state of CMC processing, and open novel processing routes for constituent development.

Effect of Low-Temperature Treatment on the Structure and Physical Properties of Castable Carbon-Containing Invar Alloys

The effect of low-temperature thermocycling treatment of castable invar alloys on the microstructure and temperature coefficient of linear expansion (CLTE) is studied. The tooling used in the production of precision articles from carbon-filled plastic should possess a maximum CLTE, temperature stability of the structure, and invariability of the coefficient of thermal expansion under the impact of thermal cycles. It is shown that an optimum castable invar alloy with steadily low coefficient of thermal expansion should contain at least 32.7 wt.% nickel and about 0.8 wt.% additional carbon. The effect of the distribution of carbon in the alloy on its structural stability is discussed.

Effects of Low Temperature Treatment at the Booting Stage and Difference of Fertilizer Composition on Yield of Paddy Rice in Volcanic Ash Soil

Effects of Low Temperature Treatment at the Booting Stage and Difference of Fertilizer Composition on Yield of Paddy Rice in Volcanic Ash Soil

Effects of low-temperature treatments on surface hardness, retained austenite content, residual stress condition and the resulting tooth root bending strength of case-hardened 18CrNiMo7-6 gears

This paper contains parts of the research project FVA 612 and investigates the correlation between low-temperature treatments of case-hardened gears made from the material 18CrNiMo7-6 and the resulting surface hardness, retained austenite content, and residual stress condition. These parameters were further investigated with regard to the tooth root bending strength obtained with pulsating test rigs. The tested gears were subjected to various low-temperature treatments including different temperature levels before or after tempering. Other investigated parameters were the application of a shot blasting treatment and the effect of low-temperature treatments on gears with increased retained austenite content after the carburizing process.

Direct analysis in real time coupled to high resolution mass spectrometry as a rapid tool to assess salmon (Salmo salar) freshness.

Direct analysis in real time-high resolution mass spectrometry (DART-HRMS) was applied to the detection of lipid species in the lipid extracts of farmed salmon samples collected from a local retailer and analyzed right after the purchase and after storage for 4 and 6days under refrigerated conditions. The recognition of type and composition of lipids detected in DART-HRMS spectra was performed by using the relevant accurate m/z data (accuracy better than 5ppm) as input for a search on the LipidMaps database. As a result, several fatty acids (FA), either saturated or mono-/poly-unsaturated, and triacylglycerols (TAG) were recognized in the three types of samples from the corresponding negative and positive ion DART-HRMS spectra, respectively. Following, spectral intensities were exploited to monitor the evolution of selected FA and TAG during the refrigeration of salmon meat. In particular, after 4days of refrigeration, a statistically significant increase was recorded for FA with side chain compositions 18:2, 18:1, 20:5, and 22:6 despite a significant decrease found for TAG with overall side chain compositions 50:4, 52:5, 52:4, and 52:3 after the same time. These evolutions were consistent with a general model already proposed for the effect of low temperature treatments on seafood, implying the action of endogenous lipases, with consequent increase of the free FA amount and decrease in glycerophospholipids and triglycerides contents. The described results indicate DART-HRMS as a promising MS-based rapid tool for the assessment of fish, or other seafood, freshness.

Effects of low temperature treatments in summer on the growth of Asiatic lily (‘Elite’) bulblets in Taiwan

Effects of low temperature treatments in summer on the growth of Asiatic lily (‘Elite’) bulblets in Taiwan

Effect of Low Temperature Treatment and Incubation Temperature on the Recruitment of Cyanobacteria Cells from the Bottom Sediments Collected at Lake Hachiro, Akita

Effect of Low Temperature Treatment and Incubation Temperature on the Recruitment of Cyanobacteria Cells from the Bottom Sediments Collected at Lake Hachiro, Akita

Negative effects of low developmental temperatures on aphid predation by Orius majusculus (Heteroptera: Anthocoridae)

Biological control agents (BCA) are often mass reared at conditions very different from those at which they have to provide their service, especially if they are to be used under field conditions. It has been suggested that biocontrol efficiency might be enhanced by acclimating the BCA under near-field conditions for some time before release (beneficial acclimation hypothesis), and some studies (e.g. with ladybirds) have supported this idea. We reared Orius majusculus, a commercially available BCA, at three temperatures (12, 16 and 20°C) throughout the whole development. The predation capacity for rosy apple aphids (Dysaphis plantaginea) of females from each of these treatments was tested at the same temperatures (12, 16 and 20°C). Additionally, we tested the effects of low temperature treatment only during the last nymphal instar, to examine if shorter treatments would have the same effects. Our results rejected the positive acclimation hypothesis. At all test temperatures predation capacity was highest for females that had developed at 20°C and lowest for those that had developed at 12°C. Thus, development at low temperatures had a detrimental effect on predatory performance (negative acclimation effect) at both high and low temperatures, and the effect was larger the longer the treatment. Mortality of the nymphs was also increased at lower temperatures. Thus, no enhanced biocontrol efficiency or production benefits were gained from low temperature treatment of O. majusculus, neither as full developmental treatment nor as a short term treatment.

Low Temperature Treatment Affects Concentration and Distribution of Chrysanthemum Stunt Viroid in Argyranthemum.

Chrysanthemum stunt viroid (CSVd) can infect Argyranthemum and cause serious economic loss. Low temperature treatment combined with meristem culture has been applied to eradicate viroids from their hosts, but without success in eliminating CSVd from diseased Argyranthemum. The objectives of this work were to investigate (1) the effect of low temperature treatment combined with meristem culture on elimination of CSVd, (2) the effect of low temperature treatment on CSVd distribution pattern in shoot apical meristem (SAM), and (3) CSVd distribution in flowers and stems of two infected Argyranthemum cultivars. After treatment with low temperature combined with meristem tip culture, two CSVd-free plants were found in ‘Border Dark Red’, but none in ‘Yellow Empire’. With the help of in situ hybridization, we found that CSVd distribution patterns in the SAM showed no changes in diseased ‘Yellow Empire’ following 5°C treatment, compared with non-treated plants. However, the CSVd-free area in SAM was enlarged in diseased ‘Border Dark Red’ following prolonged 5°C treatment. Localization of CSVd in the flowers and stems of infected ‘Border Dark Red’ and ‘Yellow Empire’ indicated that seeds could not transmit CSVd in these two cultivars, and CSVd existed in phloem. Results obtained in the study contributed to better understanding of the distribution of CSVd in systemically infected plants and the combination of low temperature treatment and meristem tip culture for production of viroid-free plants.

Influence of low temperatures on the survival of the Pacific oyster (Crassostrea gigas) infected with ostreid herpes virus type 1

Abstract Mortalities of oyster seed of Crassostrea gigas associated with ostreid herpes virus OsHV-1 μVar have been observed in many oyster producing countries since 2008. The objective of this study was to further investigate whether low temperature treatments can offer a viable option to mitigate oyster mortalities. An experiment was set-up to further evaluate the effect of low temperature treatments (10 and 13 °C vs. 21 °C) and their duration (6 d to 83 d) on the survival of oysters previously infected with OsHV-1 μVar by means of exposure to field conditions in areas where mortalities were occurring. Average survival of oysters infected with OsHV-1μVar was 71% after 83 d at low temperatures compared to only 23% in controls maintained at 21 °C. During cold-exposure, levels of OsHV-1 DNA in oyster tissues gradually decreased, down to nearly the detection limit after 24 d. However, when cold-acclimated oysters were suddenly exposed at 21 °C in the laboratory, they exhibited high levels of mortality along with an enhancement of OsHV-1 DNA concentration in their tissues. Therefore, OsHV-1 persists in oysters even at low temperature and is reactivated during subsequent thermal elevation to 21 °C. Low temperature treatments did not improve overall survival of oyster seed infected with OsHV-1. These results suggest that moving infected oysters to a cooler area only delays mortality and may increase the risk of infection in neighbouring stocks when rising temperatures become permissive for viral replication. Statement of relevance: This study is relevant for building disease control measures.

Effect of Low Temperature Cyclic Treatments on Modulus of Elasticity of Birch Wood

The modulus of elasticity (MOE) of birch (Betula platyphylla) wood specimens with four different moisture content (MC) levels, i.e., water-saturated, green, air-dried, and oven-dried, were examined under a low temperature condition ranging from -196 °C (liquid nitrogen temperature) to +20 °C (room temperature). Dynamic mechanical analysis (DMA) was used to evaluate the dynamic viscoelastic properties before and after the low temperature treatment, while X-ray diffraction (XRD) was used to analyze the crystalline structure. The results showed that MOE with different MC increased after the low temperature treatment. Specimens with higher MCs were more affected by the treatment than specimens with lower MCs. However, the effect of low temperature treatment (within four times) on MOE was not significant (P > 0.05). Cyclic treatments of liquid nitrogen did not decrease wood MOE. As a structural material, wood has a better residence to low temperatures compared to concrete, in which mechanical properties decreased dramatically after one cycle of low to room temperature.

Effect of structural water on the critical characteristics of highly textured YBa2Cu3O6.9

The effect of low-temperature treatment (200°C) in a humid argon atmosphere and subsequent annealing (930°C) on the critical parameters of a highly textured YBa2Cu3O6.9 has been studied. During annealing at T = 200°C, the absorbed water is incorporated into the structure of the compound, which is accompanied by the deterioration of its superconducting properties. However, after the recovery annealing at T = 930°C and subsequent oxidation, the superconducting characteristics (jc, B1c, and Fp) are improved. This is explained by the formation of 124-type planar defects, which are effective pinning centers, especially in high fields applied perpendicular to the c axis (⊥ c). The optimum conditions of double annealing substantially increasing the critical current density (jc ≥ 104 A/cm2) in an external magnetic field up to 10 T and also the first critical fields have been found. In fields up to ∼3 T, the critical current density jc is isotropic despite the conservation of high texture in the samples.