Study of low-temperature exposure on biotissue using an elongated cryoapplicator

The article presents the results of a study of low-temperature exposure on animal biological tissue using the novel prototype of a liquid nitrogen cryoapplicator. The data obtained are compared with the cryoapplicator characteristics cooled by nitrogen dioxide that are currently used for the atrial fibrillation treatment. Data analysis confirmed the liquid nitrogen cryoapplicators effectiveness and made it possible to highlight their advantages.

The phases and effects of low temperature exposure on embryonic development in Hermetia illucens (L.) (Diptera: Stratiomyidae)

Research on the black soldier fly (Hermetia illucens (L.) Diptera: Stratiomyidae) is steadily increasing, with a focus on its larvae and applications thereof. The egg stage of this species has received less research. This study describes the phases of embryo development for BSF eggs and the potential of delaying embryo development by using a chilling protocol. The study found that when chilling eggs for 24 hours at 10 °C and 80% relative humidity, the development is paused for a full day. This study presents a window of opportunity for embryo ages, approximately 38-58 hours post oviposition, where the hatch success is the least affected (>80% hatching when compared to control). Outside of this window, the hatch success decreases to 70% and lower. The description of embryo development can be used as a reference tool for quality control purposes. The effect of treatments on eggs can be determined by identifying key processes in development. Furthermore, the chilling of embryos and thus pausing of development can be applied in a production setting.

Differences in lipid homeostasis and membrane lipid unsaturation confer differential tolerance to low temperatures in two Cycas species

Background C. panzhihuaensis is more tolerant to freezing than C. bifida but the mechanisms underlying the different freezing tolerance are unclear. Photosynthesis is one of the most temperature-sensitive processes. Lipids play important roles in membrane structure, signal transduction and energy storage, which are closely related to the stress responses of plants. In this study, the chlorophyll fluorescence parameters and lipid profiles of the two species were characterized to explore the changes in photosynthetic activity and lipid metabolism following low-temperature exposure and subsequent recovery. Results Photosynthetic activity significantly decreased in C. bifida with the decrease of temperatures and reached zero after recovery. Photosynthetic activity, however, was little affected in C. panzhihuaensis. The lipid composition of C. bifida was more affected by cold and freezing treatments than C. panzhihuaensis. Compared with the control, the proportions of all the lipid categories recovered to the original level in C. panzhihuaensis, but the proportions of most lipid categories changed significantly in C. bifida after 3 d of recovery. In particular, the glycerophospholipids and prenol lipids degraded severely during the recovery period of C. bifida. Changes in acyl chain length and double bond index (DBI) occurred in more lipid classes immediately after low-temperature exposure in C. panzhihuaensis compare with those in C. bifida. DBI of the total main membrane lipids of C. panzhihuaensis was significantly higher than that of C. bifida following all temperature treatments. Conclusions The results of chlorophyll fluorescence parameters confirmed that the freezing tolerance of C. panzhihuaensis was greater than that of C. bifida. The lipid metabolism of the two species had differential responses to low temperatures. The homeostasis and plastic adjustment of lipid metabolism and the higher level of DBI of the main membrane lipids may contribute to the greater tolerance of C. panzhihuaensis to low temperatures.

CFD-Based Safety Assessment of a Novel Concept of a CNG Ship

The GASVESSEL project aims to prove the techno-economic feasibility of a new CNG (Compressed Natural Gas) transport concept, enabled by a novel patented Pressure Vessel manufacturing technology and a new conceptual ship design including safe on- and off-loading solution. This article describes the CFD models that have been defined for a preliminary safety assessment on the ship. Analytical models and numerical simulations were used in order to have a better understanding of the problem and give to the partners of the project the indications necessary to identify the proper solutions to improve safety on the ship. First, a possible gas leakage in the hold is analyzed, considering all side effects caused by the low temperature exposure, and a CFD study on the flow through a small crack with a high pressure differential is studied. Then the focus is moved to the compressor room, where different ventilation solutions are analyzed to reduce explosion risks in case of gas dispersion and to allow partners to understand which one best suits the requirements. Finally, an emergency vent mast system, that is activated in case of critical gas dispersion to evacuate the gas from the hold, is analyzed. In particular, the aim is to determine if the gas cloud will impact the exhaust chimneys at the ship's stern or the accommodations at the ship's bow.

QTL mapping of seedling tolerance to exposure to low temperature in the maize IBM RIL population

Maize is a cold sensitive crop that exhibits severe retardation of growth and development when exposed to cold spells during and right after germination, including the slowdown in development of new leaves and in formation of the photosynthetic apparatus. Improving cold tolerance in maize would allow early sowing to improve crop yield by prolonging a growing season and by decreasing the negative effects of summer drought, diseases, and pests. Two maize inbreds widely incorporated into American maize germplasm, B73 and Mo17, exhibit different levels of tolerance to low temperature exposure at seedling stage. In addition, thirty seven diverse inbred maize lines showed large variation for seedling response to low temperature exposure with lines with extremely low tolerance to seedling exposure to low temperatures falling into stiff stalk, non-stiff stalk, and tropical clades. We employed the maize intermated B73×Mo17 (IBM) recombinant inbred line population (IBM Syn4 RIL) to investigate the genetic architecture of cold stress tolerance at a young seedling stage and to identify quantitative trait loci (QTLs) controlling this variation. A panel of 97 recombinant inbred lines of IBM Syn4 were used to measure, and score based on several traits related to chlorophyll concentration, leaf color, and tissue damage. Our analysis resulted in detection of two QTLs with high additive impact, one on chromosome 1 (bin 1.02) and second on chromosome 5 (bin 5.05). Further investigation of the QTL regions using gene expression data provided a list of the candidate genes likely contributing to the variation in cold stress response. Among the genes located within QTL regions identified in this study and differentially expressed in response to low temperature exposure are the genes with putative functions related to auxin and gibberellin response, as well as general abiotic stress response, and genes coding for proteins with broad regulatory functions.

Duration of Low Temperature Exposure Affects Egg Hatching of the Colorado Potato Beetle and Emergence of Overwintering Adults

The Colorado potato beetle is a serious pest of Solanaceae in China. In early summer, cold spells in later spring may occur for brief periods in the field environmental conditions, and temperatures often deviate far below the normal temperature for short periods, such as sudden short-term low temperature, may affect the development of Colorado potato beetle eggs. This paper studies the effects of low temperature stress at 8 °C for 0 d, 1 d, 3 d, 5 d, 7 d, and 10 d on the development of Colorado potato beetle eggs. Our results show that egg survival is significantly affected by short-term low temperature exposure. The percentage of eggs hatched is significantly affected by different treatment times (p = 0.000)—the percentage of eggs hatched decreases with increased treatment time, and Colorado potato beetles will extend the wintering time of their soil to resist the effects of lower temperatures. Thus, exposure of Colorado potato beetles to a short-term low temperature affects their emergence and population growth; this study could provide information for the occurrence, monitoring, and early warning of Colorado potato beetle during short-term temperature.

Changes of Growth and Inflorescence Initiation by Exogenous Gibberellic Acid3 and 6-Benzylaminopurine Application in Phalaenopsis Orchids

This study was conducted to observe the effects of exogenous gibberellic acid3 (GA3) and 6-benzylaminopurine (BAP) treatments on the growth and inflorescence initiation of Phalaenopsis and to determine whether hormonal applications can substitute for low-temperature exposure for floral transition. Phalaenopsis Queen Beer ‘Mantefon’ clones were treated with no hormones (control), GA3 100 mg/L, GA3 200 mg/L, BAP 100 mg/L, and GA3 100 mg/L + BAP 100 mg/L by foliar spray. The treatments were carried at 28 °C for vegetative growth and 20 °C for forcing, respectively. At 28 °C of vegetative temperature, all exogenous hormonal treatments did not induce inflorescence initiation, but lateral shoots were observed in BAP-treated plants even though this plant is a monopodial orchid. GA3 significantly increased leaf length and decreased leaf width, and consequently increased length:width (L:W) ratio compared with the control and BAP alone. The trend grew as GA3 concentration increased. Also, the GA3 increased stem length and decreased stem diameter. At 20 °C of forcing temperature, L:W ratio responded similarly to 28 °C in GA3 treatments, but leaf size was smaller than for the control or BAP alone. BAP accelerated inflorescence emergence and significantly increased inflorescence numbers, whereas GA3 and GA3 + BAP slightly delayed inflorescence emergence. GA3 significantly promoted new leaf development at 20 °C of forcing condition. These results indicated that cytokinin was associated with the break of axillary vegetative and inflorescence meristems and exogenous GA3 spray did not improve inflorescence initiation in Phalaenopsis. Although exogenous hormonal application did not substitute for low-temperature exposure, it showed a possibility in promoting the growth and inflorescence initiation.

Effects of Low Temperature Exposure on Diapause, Development, and Reproductive Fitness of the Emerald Ash Borer (Coleoptera: Buprestidae): Implications for Voltinism and Laboratory Rearing

The emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), native to Northeast Asia, is the most destructive invasive ash (Fraxinus spp.) pest in the United States. In the present study, we evaluated the effect of exposure of diapausing mature fourth instars (J-shaped larvae, JL) of EAB to cool temperatures, either 1.7 or 12.8°C for 1–9 mo, on their post-chill development including adult emergence, longevity, and lifetime fecundity under standard rearing conditions (26 ± 0.5°C, 16:8 h L:D). In addition, we determined the effect of different stages of the larvae chilled at 12.8°C for 3 mo on the subsequent post-chill development to EAB adults. Findings from the study revealed that a period (≥2 mo) of chill at 12.8°C is required for the termination of the EAB diapause. However, chill treatment of the larvae at the near zero temperature (1.7°C) does not result in the post-diapause larval development to adults, regardless of the chill time (1–9 mo). In addition, our results showed that chill treatment of immature young larvae (L1–L4 prior to JL) results in little production of EAB adults, indicating that EAB diapause predominantly as JL. Findings of this study may be useful to laboratory rearing of EAB from eggs through continuous generations and help us understand the pest’s voltinism resulting from the diapause and post-diapause development under different climatic conditions.

ABOUT TRAINING IN THE DETERMINATION OF TOCOPHEROLS IN VEGETABLE RAW MATERIAL BY HPLC

Tocopherols, which are important biologically active substances, play the role of antioxidants. Synthesized tocopherols are usually in esterified form; their sample preparation for quantification by high performance liquid chromatography includes high temperature alkaline hydrolysis. Sample preparation of oil-containing objects having natural tocopherols in an unesterified form is carried out by direct extraction in a non-polar solvent. In this work, we determined the content of tocopherols in natural materials (the method of analysis of viscous particles) using the alkaline hydrolysis method and the direct extraction method in a non-polar solvent. It was shown that the use of normal-phase HPLC with a prepared extraction sample in hexane and low-temperature exposure allows us to determine both the total content of tocopherols and its individual forms. This option is less time consuming, requires fewer reagents, which significantly affects the cost of the analysis. It is possible to determine only the total number of tocopherols. At the same time, overestimated results were obtained, which are probably associated with the destructive destruction of both tocopherols and tocotrienols present in plants of plant origin, and one large peak, including all products, is observed in the chromatograms.