Python farming as a flexible and efficient form of agricultural food security.

Diminishing natural resources and increasing climatic volatility are impacting agri-food systems, prompting the need for sustainable and resilient alternatives. Python farming is well established in Asia but has received little attention from mainstream agricultural scientists. We measured growth rates in two species of large pythons (Malayopython reticulatus and Python bivittatus) in farms in Thailand and Vietnam and conducted feeding experiments to examine production efficiencies. Pythons grew rapidly over a 12-month period, and females grew faster than males. Food intake and growth rates early in life were strong predictors of total lifetime growth, with daily mass increments ranging from 0.24 to 19.7 g/day for M. reticulatus and 0.24 to 42.6 g/day for P. bivittatus, depending on food intake. Pythons that fasted for up to 4.2 months lost an average of 0.004% of their body mass per day, and resumed rapid growth as soon as feeding recommenced. Mean food conversion rate for dressed carcasses was 4.1%, with useable products (dressed carcass, skin, fat, gall bladder) comprising 82% of the mass of live animals. In terms of food and protein conversion ratios, pythons outperform all mainstream agricultural species studied to date. The ability of fasting pythons to regulate metabolic processes and maintain body condition enhances food security in volatile environments, suggesting that python farming may offer a flexible and efficient response to global food insecurity.

Epidemiology of hepatitis B e antigen and antibody in mentally retarded HBsAg carriers.

Screening for HBeAg and anti-HBe was performed on 133 carriers of HBsAg in an institution for the mentally retarded. By radioimmunoassay, the prevalences of HBeAg and anti-HBe were determined to be 16 and 78%, respectively. HBeAg prevalence was significantly different in the following pairs of carriers: 70% in blacks, 10% in whites, and 35% in carriers with Down's syndrome, 8% in carriers without Down's syndrome. Mean age of HBeAg-positive carriers (25.7 years) was lower than HBeAg-negative carriers (29.6 years, p less than 0.05). SGPT levels were abnormal in 66% of HBeAg-positive and 25% of HBeAg-negative carriers (p less than 0.01). This suggests an association between HBeAg positivity and functional liver impairment.

Hepatocellular carcinoma in young, mentally retarded HBsAg carriers without cirrhosis.

In a Californian institution for the mentally retarded, surveillance by autopsy of all deaths (n = 138) identified three cases of hepatocellular carcinoma. Hepatocellular carcinoma cases occurred in young (mean age = 26 years) male carriers of HBsAg and were not associated with cirrhosis. They were of the nonfibrolamellar oncocytic type and were rapidly fatal. Hepatocellular carcinoma incidence in HBsAg carriers was estimated to be 246 times greater than United States males.