The radio-infrared correlation in galaxies

The radio-infrared correlation was explained as a direct and linear relationship between star formation and IR emission. However, one fact making the IR-star formation linkage less obvious is that the IR emission consists of at least two emission components, cold dust and warm dust. The cold dust emission may not be directly linked to the young stellar population. Furthermore, understanding the origin of the radio-IR correlation requires to discriminate between the two main components of the radio continuum emission, free-free and synchrotron emission. Here, we present a multi-scale study of the correlation of IR with both the thermal and non-thermal (synchrotron) components of the radio continuum emission from the nearby galaxies M33 and M31.Comment: To appear in Highlights of Astronomy, Volume 15, XXVIIth IAU General Assembly, August 200

Effect of Salicylic Acid and Ascorbic Acid on Germination Indexes and Enzyme Activity of Sorghum Seeds under Drought Stress

Seed priming methods have been used to increase germination characteristics under stress conditions. The effects of drought stress (0, -4, -8, -12 and -16 bar) and salicylic acid 25 ppm at 15 °C for 15 h and ascorbic acid 25 ppm at 15 °C for 15 h on germination percentage, germination index, means time to germination, normal seedling percentage and enzyme activity were assessed in the laboratory for sorghum seeds (Sorghum bicolor L.). Results showed that the highest germination percentage (83.33%), normal seedling percentage (69.67%), germination index (25.29) and the minimum means time to germination (2.87) were attained from priming with salicylic acid in control conditions. Therefore, seed priming significantly (p≤ 0.01) increased germination characteristics as compared to the unprimed under drought stress. Also, priming increased catalase and ascorbate peroxidase as compared to the unprimed seeds

The Effect of Priming on Germination and Enzyme Activity of Sesame (Sesamum indicum L.) Seeds After Accelerated Aging

Maximum germination percentage achieves immediately after harvesting and gradually de#creases with storage time. Aging is one of the key factors in plant yield loss especially in vegetables. Seed aging is the main problem of seed storage. Application of accelerated aging treatment is used to assess seed vigor and quality. Seed priming enhances seed germination performance after aging. An experiment was conduct in order to investigate the activity of catalase and ascorbate peroxidase during accelerated aging and repair during priming treatment of sesame (Sesamum indicum L.) seeds. In order to improve germination characteristics in aged seeds with seed priming. Our result showed that seed priming treatments significantly (p≤ 0.01) affected, germination percentage, germination Index and normal seedling percentage after aging (0, 3 and 6 days). Increasing aging duration resulted higher reduction in germination characteristics. Priming with gibberelic acid (GA) increased germination characteristics of seed aged. The highest germination percentage, germination index, normal seedling percentage and enzyme activity were achieved in control conditions (0 day of aging). Also antioxidant activity of aged seeds increased after seed priming