In geography and fluvial geomorphology, a thalweg or talweg (/ËtÉËlvÉÉ¡/) is the line of lowest elevation within a valley or watercourse. Under international law, thalwegs can acquire special significance because disputed river borders are often deemed to run along the river's thalweg. 1 Etymology.
However, when they are 3 to 4 months old, they become susceptible to the disease, so all calves should be vaccinated for blackleg by 4 months of age. A revaccination 3 to 6 weeks later according to product label directions is necessary to provide the best protec-tion.lackleg seldom affects cattle older than 2 years of age, most likely due to immunity induced by vaccines or natural exposure. However, sporadic cases do occur in cattle older than 2 years and are often associated with the reuse of needles for multiple injections.
For infants born to HBsAg-positive mothers, postvaccination testing should be performed 1â2 months after completion of â¥3 doses of a licensed hepatitis B vaccine series (i.e., at age 9â18 months, generally at the next well-child visit).his vaccine cannot be administered at birth, before age 6 weeks, or after age 71 months. â . Â§ Combined Hepatitis A and hepatitis B vaccine. This vaccine is recommended for persons aged â¥18 years who are at increased risk for both hepatitis B virus and Hepatitis A virus infections.