The microbial process of methane (CH4) production during the back-freezing of permafrost soils in autumn and the future fate of produced CH4 in the thawing phase of the following spring are not well understood. Long-term CH4 flux studies in the Lena Delta (Siberia) indicate that back-stored CH4 adds to the emission of newly-produced CH4 at the beginning of the vegetation period. Further field a...

A total of 30 ejaculates from three Hampshire crossbred boars were used to study the effect of freezing rates and thawing methods on quality of frozen boar semen. Semen was frozen using three freezing rates-30 0 c/min, 50 0 c/min and 70 0 c/min in a programmable biological semen freezer. The semen characteristics viz., sperm motility, live sperm, HOST reacted spermatozoa and intact acrosome wer...

1. The hemagglutinating capacity, enzymic activity, and infectivity of several influenza viruses were destroyed by repeated freezing and thawing of dialyzed allantoic fluids containing them. 2. Influenza virus degraded by freezing and thawing, by treatment with 5 M urea, or by heating at 65 degrees C. still combined with homologous antibody and was demonstrable by blocking of the hemagglutinati...

Repeated freeze-thaw cycles are common and are increasing in frequency with climate change in many temperate locations, yet understanding of their impact on freeze-tolerant insects is extremely limited. We investigated the effects of repeated freezing and thawing on the freeze-tolerant final instar caterpillars of the moth Pyrrharctia isabella (Lepidoptera: Arctiidae) by subjecting individuals ...

BACKGROUND The repeated freeze-thaw events during cold season, freezing of soils in autumn and thawing in spring are typical for the tundra, boreal, and temperate soils. The thawing of soils during winter-summer transitions induces the release of decomposable organic carbon and acceleration of soil respiration. The winter-spring fluxes of CO2 from permanently and seasonally frozen soils are ess...

The structural and functional properties of non-gelatinized waxy rice starch were investigated after 1, 3, 7, and 10 freezing/thawing cycles. Freezing caused an increasing damaged starch from 1.36% in native waxy rice starch to 5.77% in 10 freezing/thawing-treated starch (FTS), as evidenced by the cracking surface on starch granules. More dry matter concentration was leached, which was characte...

This study reports an industrially applicable non-sterile xylitol fermentation process to produce xylitol from a low-cost feedstock like corn cob hydrolysate as pentose source without any detoxification. Different immobilization matrices/mediums (alginate, polyvinyl alcohol, agarose gel, polyacrylamide, gelatin, and κ-carrageenan) were studied to immobilize Candida tropicalis NCIM 3123 cells fo...

The food-borne pathogen Listeria monocytogenes can grow in a wide range of temperatures, and several key virulence determinants of the organism are expressed at 37 degrees C but are strongly repressed below 30 degrees C. However, the impact of growth temperature on the ability of the bacteria to tolerate environmental stresses remains poorly understood. In other microorganisms, cold acclimation...

The first and basic cause of the failure of concrete is repeated freezing (thawing) of moisture contained in the pores, microcracks, and cavities of the concrete. On transition to ice, water existing in the free state in cracks increases in volume, expanding the recess in which freezing occurs. A reduction in strength below the initial value is to be expected and further cycle of freezing and t...

introduction: sperm cryopreservation is widely used as a way of preserving the male sperm used in future artificial insemination and fertilization. despite all the recent advances in cryopreservation technology, sperm motility is negatively affected by freezing and the thawing afterwards. yet hyaluronic acid is believed to improve the vitality and motility of the sperm, enhancing the physiologi...