STUDIES ON THE HOUSEFLY (MUSCA DOMESTICA L.): II. THE EFFECTS OF LOW TEMPERATURES ON LABORATORY-REARED PUPARIA

1948 ◽  
Vol 26d (1) ◽  
pp. 26-56 ◽  
Author(s):  
G. E. Bucher ◽  
A. Wilkes ◽  
J. W. MacB. Cameron

Investigations are reported on factors influencing the survival of housefly (Musca domestica L.) puparia exposed to different intensities of low temperature storage above 1 °C. Survival was decreased by lowering the temperature of storage and by increasing the duration of the storage period, or both. Mortality of adults following puparial storage was influenced by the type of rearing container used, crowding, age of puparia, humidity, concentration of gases in the pupal rearing chambers, and to some extent by changes in the food of the immature larvae but not by the age or sex ratio of the parental stock, the size of puparia, selective breeding of resistant individuals or different strains of stock. Death did not occur in cold storage but during subsequent incubation at normal temperatures and at a definite stage in development near adult emergence. Temperatures below the threshold of development caused physiological disturbances that affected the longevity, oviposition, and hatchability of eggs of the adults that survived. A proposed explanation is given of the lethal effects of low temperatures based on the interrelationships of disturbances between the relative rates of development and differentiation of various ontogenetic systems.

Food systems ◽  
2018 ◽  
Vol 1 (3) ◽  
pp. 27-32 ◽  
Author(s):  
Natalya Yu. Sharova ◽  
Tatyana V. Vybornova ◽  
Anastasia A. Printseva ◽  
Bairta S. Manzhieva

Collection cultures of actinomycetes are mainly stored in a dried state on adsorbents. Practiced low-temperature storage of actinomycetes at minus 70°C. The article presents the results of investigations of the properties of the conidia of strains of the actinomycete Streptomyces lucensis VKPM Ac–1743 and Streptomyces violaceus VKPM Ac–1734 is in the process of storage at minus 12°C and minus 18°C in glycerin solution and in 0,9 % aqueous sodium chloride solution. It was found that the inhibitory activity in the native solution for the studied strains stored in the glycerin solution at minus 12°C and plus 4°C, as a result of their subsequent cultivation on the starch hydrolyzate for 120 h is at the level of (450 ± 10) IE/cm3. The indicator for crops stored at minus 18°C was higher (560 ± 10) IE/cm3. Low-temperature storage of conidia in saline solution is less effective. Pigmentation is more active in the cultivation of strains stored at minus 18°C.


2011 ◽  
Vol 39 (2) ◽  
pp. 141-144 ◽  
Author(s):  
Sung-Ryul Ryu ◽  
Kang-Hyeon Ka ◽  
Bong-Hun Lee ◽  
Hyun Park ◽  
Won-Chull Bak

1948 ◽  
Vol 21 (4) ◽  
pp. 864-876
Author(s):  
John B. Gregory ◽  
Irving Pockel ◽  
John F. Stiff

Abstract A new method for measuring the flexibility of rubber has been described. The method consists essentially in determining the stress-strain curve obtained by loading and unloading a loop formed from a one-inch by six-inch strip cut from a test slab. A coefficient of flexibility independent of the thickness of the sample and, in addition, information on per cent resilience were obtained. By the use of the method described, the behavior of various natural and synthetic rubber gas mask facepiece compounds was studied during one month to three months' exposure at various temperatures down to −20° F. Progressive stiffening probably due to crystallization was found for natural rubber, GR-I, and GR-M compounds at low temperatures. No tendency to crystallize was noted for the GR-S compound. Of the crystallizable polymers GR-I was the most resistant, and GR-M the least resistant to stiffening during low temperature storage. It is of course evident that different polymers have inherently different degrees of resistance to low temperatures. Disregarding these inherent differences the work reported indicates that the resistance of elastomer compounds to stiffening during prolonged low temperature storage is favored by the following: 1. Use of interpolymers made from monomer mixtures having a relatively large proportion of each component, thus obtaining mutual intereference with crystallization. 2. Use of a “tight” cure which probably so impedes the movement of the polymer chains as to make crystallization difficult.


Author(s):  
Elsadig A. Eltayeb ◽  
Sana Salem Al-Sinani ◽  
I. A. Khan

Tubers from 7 potato varieties were analyzed for their rates of glycoalkaloid accumulation in response to stresses of three types of mechanical injury and low temperature storage. Mechanical injuries were found to greatly stimulate glycoalkaloid accumulation in both peel and flesh of tubers. The extent of glycoalkaloid accumulation appears to depend on variety, type of mechanical injury, and storage period. Most of the injury-stimulated glycoalkaloid accumulation occurred within 7 and 14 days after treatment. Cutting the tubers resulted in the highest content of glycoalkaloids both in flesh and peel up to levels that exceeded the upper safety limit of 200 mg/kg FW. Injury stimulated α-solanine accumulation in stored potato tubers is more than α-chaconine, resulting in a decrease in the α-chaconine: α-solanine ratio. When tubers were stored at low temperature, the rate of glycoalkaloid accumulation was found to be independent of the glycoalkaloid level at harvest. The greatest increase in total glycoalkaloid content of the seven varieties was found after two weeks of storage at both 4 ºC and 10 ºC. Further storage at these temperatures resulted in a decrease in the rate of glycoalkaloid accumulation in most of them. At 10 ºC glycoalkaloid content tended to increase more rapidly than at 4 ºC. The α-solanine content of the tubers showed an increase following low temperature storage.  


Author(s):  
Shafa Shofiani ◽  
Junianto . ◽  
Iis Rostini ◽  
Eddy Afrianto

This research aimed to know the shelf life of mullet fillet with basil leaves extract treatment in different concentration based on the amount of bacteria contained on mullet fillet during low temperature storage. The research was conducted at The Central Laboratory and The Laboratory of Fishery Product Processing, Padjadjaran University, Jatinangor. The method used in this research was experimental with four treatments by duplo. Basil leaves extract treatment concentrations were given in 0%, 1.5%, 3% and 4.5% concentrations, soaked for 30 minutes and stored at low temperature (5-10℃). The observations for grey mullet fillet with 0% concentration (without soaking on basil leaf extract treatment) were made on the 1st, 3td, 5th, 6th, 7th, 8th and 9th day of research. The observations for 1.5%, 3% and 4.5 concentrations were made on the 1st, 3rd, 5th, 6th, 7th, 8th, 9th, 10th, 11th and 12th day of storage period. The parameters observed in this research was the amount of bacteria. The result of research showed that the use of basil leaf extract in concentration of 3% on mullet fillet during low temperature storage has the longest shelf life, that was until 11 days with total amount of bacteria about 4.55 x  cfu/g.


2016 ◽  
Vol 19 (3) ◽  
pp. 321 ◽  
Author(s):  
Windi Damayanti ◽  
Emma Rochima ◽  
Zahidah Hasan

This research was conducted in the Laboratory of Fishery Products Processing, Faculty of Fisheries and<br />Marine Science, University of Padjadjaran, Jatinangor. The purpose of this research is to obtain the optimal<br />concentration of chitosan as an antibacterial material wich had the longest of storage period of pangasius<br />fillet at low temperature storage (5-10oC). The method used is an experimental method with a completely<br />randomized design, four treatments and three replications. Pangasius fillet was soaked with chitosan 0%,<br />1%, 2% and 3% for 3 minutes, then packed with styrofoam and plastic wrap and stored at low teperature.<br />The observation were made on day 1st, 3rd, 5th, 6th ,7th, 9th,10th, 11th and 12th. The parameters observed<br />total bacterial colonies, the degree of acidity (pH), weight loss, and antibacterial activity of chitosan using<br />disc diffusion methods. The final conclusion is that the 2% chitosan is optimal concentration for pangasius<br />fillet storage at a low temperature until day 11th, with a total 6.7 X105 cfu/g of bacterial colonies, pH 6.67 and<br />total 6,78 % of weight loss.Chitosan also has a higher antibacterial capability against Escherichia coli (Gram<br />negative bacteria) than Staphylococcus aureus and Bacillus subtilis (Gram positive bacteria).


2018 ◽  
Author(s):  
Elison Floriano Tiago ◽  
Fabrício Fagundes Pereira ◽  
Samir Oliveira Kassab ◽  
Rogério Hidalgo Barbosa ◽  
Carlos R Garcia Cardoso ◽  
...  

Introduction: The endoparasitoid Tetrastichus howardi (Olliff, 1893) (Hymenoptera: Eulophidae) can be reared with the alternative host Tenebrio molitor (Linnaeus, 1758) (Coleoptera: Tenebrionidae). Host storage at low temperatures can regulate parasitoid production and demand in biological control programs. Material and Methods: The life-cycle (egg-adult), parasitism and emergence percentage, number of parasitoids emerged per host pupae, sex ratio and longevity of the T. howardi offspring per T. molitor pupa were evaluated after low temperature storage of this host for different periods and its immature (pupae) in T. molitor pupae for five periods at 10.3 ºC. Tenebrio molitor pupae stored at 0.5 ± 0.09 °C and 2.7 ± 0.11 °C for 10 and 20 days, respectively, were adequate to produce T. howardi. Results: The biological characteristics of this parasitoid were better with T. molitor pupae stored at 0.5 ± 0.09 °C and 2.7 ± 0.11 °C for 10 and 20 days. Tetrastichus howardi immature (pupae) can be stored in T. molitor pupae for 10, 20, 30, 60 and 90 days at 10.3 ºC, preferably in pupae of this host for 10 days to produce these adults of this parasitoid for biological control programs. Discussion: These results contribute to overcoming one of the difficulties encountered in the massive production of parasitoids which is to obtain large numbers of suitable hosts when they are needed. Therefore, the possibility of conserving T. molitor pupae to rear T. howardi will be useful to use this natural enemy in biological pest control programs. Keywords: Biological control, Cold storage, Parasitoids, Progeny.


2016 ◽  
Vol 24 (2) ◽  
pp. 257
Author(s):  
Yennita - Sihombing

Demand for mangosteen fruits (Garciana mangostana L) is currently increasing both for local and export markets. Quality of mangosteen fruit has been kept until now, even increased by efforts of post-harvest handling. The problem on postharvest of mangosteen is mainly on storage process. The quality of mangosteen is affected by the temperature condition during storage period. Waxing is usually used for fruits to extend their shelf life. In this study, combination of waxing and low temperature storage were studied to obtain the optimum storage condition for mangosteen. The objectives of this study were to determine the effect of combination of waxing and low temperature storage on the quality changes of mangosteen. It was shown that storage of mangosteen with waxing treatment of 5% and temperature storage of 8oC resulted the longest period of storage, i.e., 39 days. At this condition, the firmness was 2.00 kgf, total soluble solid was 16.10oBrix, and respiration rate of CO2 was 1.67ml/kg hr. In this study, prediction of storage life of mangosteen was carried out based on the firmness which accepted by panelist from organoleptic test. It is shown that waxing concentration 0% and temperature storage 8oC effectiveness to storage life until 16 days.


2021 ◽  
Vol 328 ◽  
pp. 08010
Author(s):  
Nur Ducha ◽  
Widowati Budijastuti ◽  
Dwi Anggorowati Rahayu

The goal of this study was to investigate the reproductive profile of male Senduro Goats as superior male candidates based on data of semen quality. The experiment was carried out on ten male Senduro Goats kept at the Singosari Animal Husbandry Service Unit in East Java, Indonesia. An artificial vagina was used to collect sperm. The macroscopic and microscopic qualities of fresh Senduro Goat sperm have been observed. Color, volume, smell, pH, and viscosity were examples of macroscopic observations. Concentration, motility, viability, and membrane integrity were examples of microscopic observations. The results of macroscopic observations showed that the average of Senduro Goat semen was milky white; with volume 1,24 ± 0,22; 6.77 ± 0.05; thick semen. The results of microscopic observations showed that there was concentration 2,5 x 109 ± 0.1; mass motility +++; individual motility 77.5% ± 2.63; viability 88.98% ± 2.07; membrane integrity 89.71 ± 1.69. Based on the results of these studies, it can be concluded that the semen of Senduro Goat has good quality so it can be processed further, namely storage at low temperatures and applied to Artificial Insemination technology.


2013 ◽  
Vol 59 (2) ◽  
pp. 219-234
Author(s):  
O.V. Falko ◽  
N.G. Zemlianskykh ◽  
O.V. Lipina ◽  
O.S. Procopyuk

Changes in environmental physical and chemical factors upon freeze-thawing and low temperature storage of biological samples can result in impairments of protein structures. This work specifies spontaneous and diamide-induced protein aggregations of placenta blood serum stored at -20° and -196°C during 2 years with SDS-PAGE. It was shown that storage of placenta blood serum at low temperatures did not cause any quantitative and qualitative changes in fraction distribution of proteins denatured with SDS in comparison to the native samples which were not frozen. Application of b-mercaptoethanol revealed that placenta blood serum proteins upon freeze-thawing did not form spontaneous aggregates linked by disulphide bridges. Oxidation of amino acid sulfhydryl groups induced by diamide and accompanied by high molecular aggregate formation proved to be a quite effective way for indirect estimation of structural changes in protein upon low temperature effects. In samples thawed after low temperature storage the protein aggregation with 4 mM diamide was significantly higher than in native serum. These discrepancies between native and frozen-thawed samples are stipulated by impairments of protein structure under low temperature and increased in accessibility of reactive SH-groups of proteins for oxidation with diamide. Structural changes in placenta blood serum proteins, which caused by low temperatures and revealed by elevated sensibility to diamide-induced aggregate formation, did not depend on temperature (-20° и -196°C) and storage terms (2 years and 3 weeks). They reflect protein reaction to freeze-thawing processes and could be sequence of ice crystal formation which takes place in unprotected media.


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