Large responses of ecosystems to small changes in the conditions--regime shifts--are of great interest and importance. In spatially extended ecosystems, these shifts may be local or global. Using empirical data and mathematical modeling, we investigated the dynamics of the Namibian fairy circle ecosystem as a case study of regime shifts in a pattern-forming ecosystem. Our results provide new su...

Shrimp farming in Iran is one of the fast growing segments of the economy. In 1994, around 1% of Iranian shrimp production was farmed and by 2004 the share of shrimp farming increased to 60%. In spite of the fact that shrimp culture had relatively rapid growth in last decade, due to increase in production cost and decrease in international price, the profit of shrimp production has decreased in...

Fairy circles consist of isolated or randomly distributed circular areas devoid of any vegetation. They are observed in vast territories in southern Angola, Namibia and South Africa. We report on the formation of fairy circles, and we interpret them as localized structures with a varying plateau size as a function of the aridity. Their stabilization mechanism is attributed to a combined influen...

Patients with Alzheimer's disease (AD) suffer from distortions of memory. Among such distortions, intrusions in memory tests are frequently observed. In this study we describe the performance of a group of mild AD patients and a group of normal controls on the recall of three different types of stories: a previously unknown story, a well-known fairy-tale (Cinderella), and a modified well-known ...

Temporary pool inhabitants face altered inundation regimes under climate change. While their exposure to these changes has received considerable attention, few studies have investigated their sensitivity or adaptability. Here, we use zooplankton as a model to explore how decreasing hydroperiods affect extinction risks and assess whether changes in life history traits could promote persistence. ...

BACKGROUND Shrimp is a frequent cause of food allergy. Tropomyosin is the major allergen in shrimp, and it shares homology to tropomyosins from other crustaceans, dust mites, cockroach, and parasites. OBJECTIVE The aim of this study was to determine the value of detection of IgE to shrimp tropomyosin in the diagnosis of shrimp allergy. METHODS We have studied 35 patients with asthma, rhinit...

The survey on tilapia-shrimp polyculture was conducted in Thailand and Vietnam from March through June 2002. The survey conducted in Thailand was to assess the current status of farmers’ practice of tilapia-shrimp polyculture, while the survey conducted in Vietnam was to find out why Vietnamese shrimp farmers do not grow tilapia in shrimp ponds. In twelve provinces of Thailand, 61 farmers who c...

Vertebrates that eavesdrop on heterospecific alarm calls must distinguish alarms from sounds that can safely be ignored, but the mechanisms for identifying heterospecific alarm calls are poorly understood. While vertebrates learn to identify heterospecific alarms through experience, some can also respond to unfamiliar alarm calls that are acoustically similar to conspecific alarm calls. We used...