Searching for new hypercompact HII regions

Hypercompact (HC) HII regions are, by nature, very young HII regions, associated with the earliest stages of massive star formation. They may represent the transition phase as an early B-type star grows into an O-type star. Unfortunately, so few HCHII regions are presently known that their general attributes and defining characteristics are based on small number statistics. A larger sample is needed for detailed studies and good statistics. Class II methanol masers are one of the best indicators of the early stages of massive star formation. Using the Arecibo Methanol Maser Galactic Plane Survey - the most sensitive blind survey for 6.7 GHz methanol masers to date - we selected 24 HCHII region candidates. We made EVLA continuum observations at 3.6 and 1.3 cm to search for HCHII regions associated with these masers. We identified six potential HCHII regions in our sample based on the presence of optically thick free-free emission. Overall, we find that 30% of the methanol masers have an associated centimeter radio continuum source (separation less than 0.1 pc), which is in general agreement with previous studies.Comment: Accepted for publication in ApJL, in the Special Issue of the EVL

Recruitment of postlarval penaeid prawns in the Vellar estuary, South India

Abstract only.The northern bank of Vellar estuary (Parangipettai, India) is ideal for postlarval penaeid prawn recruitment. The annual recruitment, distribution and the substratum preference of postlarval immigrants at three different stations in the estuary were studied in detail. Among the postlarvae of Penaeus, P. (Fenneropenaeus) indicus was dominant followed by P. (Penaeus) monodon, P. (P.) semisulcatus, P. (F.) merguiensis and P. (Melicertus) latisulcatus. In Metapenaeus, postlarvae of M. monoceros were abundant followed by M. dobsoni, M. affinis, M. bre-vicornis and M. lysianassa. Two peaks were observed in the postlarval penaeid prawn population. In P (F.) indicus and P. (P.) monodon, the primary peak occurred from January to April and the secondary peak from July to September. In M. monoceros and M. dobsoni, the primary peak was from March to May and the secondary peak from August to September. The postlarvae of P. (F.) indicus, P. (P.) monodon, M. monoceros and M. dobsoni were available throughout the year while the others were seasonal. The distribution of postlarvae in the estuary is related to the type of substratum, salinity and temperature. The postlarval population declined during the northeast monsoon (November-December) and in peak summer (May-June). Their abundance decreased in the lower salinity areas of the upper reaches of the estuary

Yolk utilization and hatching time in the Canadian lobster Homarus americanus

During the course of its embryonic development, the Canadian lobster Homarus americanusMilne-Edwards exhibits steady increases in water content (56.2 to 86.8%) and ash (5.8 to 21.2%), and a progressive decrease in energy content from 6636 to 4292 cal/g dry weight. Mean dry weight of a single egg is 965 μg, equivalent to 6.4 cal; a freshly hatched egg. The lobster hatches about 1,500 larvae per night over a period of 4 to 5 days. Dry weight, ash and calorific contents of larvae hatched on different days show considerable variations. After larvae hatch on the first day, continuous salt absorption by eggs to hatch on subsequent days leads to a steady increase in ash content from 143 μg/larva hatched on the first day to 255 μg/larva hatched on the fourth day, and consequently, to an increase in dry weight from 854 to 956 μg/larva. Metabolism of embryos (0.1 cal/day), which are yet to be hatched on subsequent days, depletes the calorific content per unit weight (from 4637 to 3837 cal/g dry weight) as well as per larva (from 3.98 to 3.67 cal)

The resource-based view within the conversation of strategic management

Includes bibliographical references

Scope for commercial culture of tilapia

The suitability of tilapia species for fish culture and the potential for the development of commercial culture operations in India are discussed. Sex regulation, monosex tilapia polyculture, chromosome manipulation and sex reversal, nutrition and feed formulation are examined in detail

We’ve Got Your Back: New Studies in Spinal Cord Regeneration

Every day, the spinal cord transmits messages between the brain and body at speeds of 270 miles per hour. The spinal cord allows us to walk, run, or swim. However, for 200,000 Americans who suffer from spinal cord injury (SCI), simply standing up is often not a possibility. This number rises by approximately 17,000 cases a year as a result of sports injuries, car accidents, motorcycle collisions, or falls. Unlike many cells in the body, the neurons in the spinal cord cannot regenerate after an injury, which means spinal cord injuries tend to last for the remainder of one’s lifetime