Paralytic shellfish poisoning (PSP) is one of the four recognized syndromes of shellfish poisoning, which share some common features and are primarily associated with bivalve mollusks (such as mussels, clams, oysters and scallops). These shellfish are filter feeders and accumulate neurotoxins, chiefly saxitoxin, produced by microscopic algae, such as dinoflagellates, diatoms, and cyanobacteria. Dinoflagellates of the genus Alexandrium are the most numerous and widespread saxitoxin producers and are responsible for PSP blooms in subarctic, temperate, and tropical locations. The majority of toxic blooms have been caused by the morphospecies Alexandrium catenella, Alexandrium tamarense, Gonyaulax catenella and Alexandrium fundyense, which together comprise the A. tamarense species complex. In Asia, PSP is mostly associated with the occurrence of the species Pyrodinium bahamense.Some pufferfish, including the chamaeleon puffer, also contain saxitoxin, making their consumption hazardous. PSP and cyanobacteria
Saxitoxin can be produced in both eukaryotic dinoflagellates as well as prokaryotic cyanobacteria (usually referred to as blue-green algae). The biosynthesis pathway of this toxin within cyanobacteria is well defined, while the pathway within dinoflagellates is mostly unknown. Within cyanobacteria the saxitoxin pathway is complex with many steps, enzymes and chemical reactions. Using radioisotope tracing experiments scientists have determined how the initial reagent of the pathway, L-arginine (via acetyl-CoA), turns into this toxin. L-arginine goes through a rare reaction known as Claisen condensation forming four intermediates before turning into the final product of saxitoxin.Cyanobacteria is general responsible for the accumulation of PSP toxins, mainly being saxitoxin, within freshwater marine life.
In general, higher IQs are correlated with greater responsiveness to treatment and improved treatment outcomes. Services should be carried out by behavior analysts, special education teachers, speech pathologists, and licensed psychologists. Intensive, sustained special education programs and behavior therapy early in life often improves functioning and decreases symptom severity and maladaptive behaviors; claims that intervention by around age three years is crucial are not substantiated.No known medication relieves autisms core symptoms of social and communication impairments. Education
Early, intensive ABA therapy has demonstrated effectiveness in enhancing communication and adaptive functioning in preschool children; it is also well-established for improving the intellectual performance of that age group. It is not known whether treatment programs for children lead to significant improvements after the children grow up, and the limited research on the effectiveness of adult residential programs shows mixed results. Alternative medicine
Although many alternative therapies and interventions were used, few are supported by scientific studies. Treatment approaches have little empirical support in quality-of-life contexts, and many programs focus on success measures that lack predictive validity and real-world relevance. Some alternative treatments placed autistic individuals at risk. For example, in 2005, a five-year-old child with autism was killed by botched chelation therapy (which is not recommended for autism as risks outweigh any potential benefits). Epidemiology
Globally, classic autism was understood to affect an estimated 24.8 million people as of 2015.