Development of hypoparathyroidism after excision of laryngeal rhabdomyosarcoma in a dog

An uncommon neoplasm of the larynx, rhabdomyosarcoma, was diagnosed in a 6-year-old 14-kg neutered female Spitz. In addition to the progressive onset of expected clinical signs of the tumor (exercise intolerance, respiratory stridor, inability to bark), the dog experienced hyperthermic crisis. Laryngectomy was successful in eradicating the local neoplastic tissue; however, unusual postoperative complications developed and included acute complications of pharyngotracheal fistula and hypoparathyroidism, and long-term complications of periodic collapse of the tracheal stoma and intolerance to heat. Probable causes and successful management of these complications are described. At 22 months after laryngectomy, the dog was admitted for a solitary hepatic metastasis. While hospitalized, the dog died of apparent asphyxiation attributable to stoma collapse.     

A fatal disease outbreak in sheep associated with Salmonella enteritidis ser Havana

A disease outbreak with a mortality rate of 50% in a mob of wether lambs is described. Salmonella enteritidis ser Havana and pathogenic levels of Trichostrongylus sp. were implicated as causal agents.     

Survivorship, tunneling and feeding behaviors of Coptotermes formosanus (Isoptera: Rhinotermitidae) in response to 2'-acetonaphthone-treated sand

In laboratory tests, 2'-acetonaphthone was incorporated into sand at different concentrations (4.16-200 mg kg(-1)) and evaluated for survivorship, feeding and tunneling effects on the Formosan subterranean termite, Coptotermes formosanus Shiraki. 2'-Acetonaphthone at 8.33 mg kg(-1) sand significantly reduced survivorship (89-94%), tunnel area (68-91%) and food consumption (84-100%) compared with the control. Most of the dead workers were found at the release point and a few had traveled to the surface of the treated sand. Malformed workers (< or =27%) with an unexpected symptom of molting failure were observed, particularly at the lowest concentration tested (4.16 mg kg(-1)). In choice assays, threshold concentration for significant reduction in survivorship, tunnel construction in treated sand and food consumption in the treated-sand side was 8.33mg kg(-1) with termites collected from New Orleans, LA and 35.0 mg kg(-1) for those from Lake Charles, LA. Termites actively fed and tunneled in the untreated sand, whereas 2'-acetonaphthone at 140mg kg(-1) completely inhibited consumption of food placed on the treated sand.     

Evolving core-periphery interactions in a rapidly expanding urban landscape: The case of Beijing

We characterized and analyzed the dynamics of a rapidly expanding urban landscape of Beijing Municipality, based on the Hierarchical Regional Space (HRS) model. We focused on ecological processes such as flows of energy, materials and population between the urban core and its periphery, and how these processes co-evolved with urbanization. We treated the HRS as an alternative to the cellular automata (CA) approach to characterizing and modeling of landscape dynamics. With LANDSAT data, we showed that the urban area of Beijing expanded from 269 km² to 901 km² in the period from 1975 to 1997, an increase of 2.35 times in 22 years. Meanwhile, a number of secondary urban centers formed on areas that used to be sparsely populated around the city. These secondary centers quickly expanded and ultimately merged with each other and with the urban core. The changes in spatial pattern and organization were accompanied by evolution of urban functions and particularly the interactions between the urban core and its periphery. We demonstrated a dramatic increase in dependence of the urban core on the periphery as well as the cores influence on the periphery with a case analysis of the vegetable supply to Beijing. The tightening link between the city and its periphery reinforces the urbanization process and further drives the transformation of the regions landscape. We conclude that the HRS model is capable of characterizing the patterns and processes of complex and dynamic landscapes such as the case of Beijing, and this model has great potential for quantitative modeling of human dominated landscapes as well.This revised version was published online in May 2005 with corrections to the Cover Date.