Efficacy of X-Ray Phytosanitary Irradiation on the Infectivity and Reproduction of Angiostrongylus cantonensis in Experimentally Infected Rats.

Angiostrongylus cantonensis is a globally distributed nematode and the leading cause of eosinophilic meningitis in humans. As a global hotspot for this disease, Hawaii's agricultural exports may be contributing to the spread of A. cantonensis. Phytosanitary irradiation doses of 150 or 400 Gy provide quarantine security against multiple insect pests. We evaluated the in vitro and in vivo effects of phytosanitary irradiation on infectious, third-stage, A. cantonensis larvae. In vitro experiments directly exposed larvae to irradiation doses ranging from 200 to 1,000 Gy. Results showed low mortality and no dose response across all treatments 27 days post-irradiation. In vivo studies isolated larvae from wild-caught Parmarion martensi after exposure to x-ray irradiation at doses of 0, 150, and 400 Gy and infected them into laboratory rats. Fourteen rats were assigned to each treatment and infected with 50 larvae from their assigned irradiation dose. Results at 3 and 6 weeks post-infection demonstrated a significant negative dose response in regard to the number of larvae that migrated to the brain and adults found in the pulmonary artery. No irradiated larvae that grew into adults were able to produce eggs. These findings indicate that x-ray irradiation does not result in the direct mortality of A. cantonensis larvae; however, it does affect the infectivity and reproduction of A. cantonensis within its definitive host, the rat. Phytosanitary irradiation at doses ≥150 Gy appears to be an effective means of preventing the establishment of viable populations of A. cantonensis, thus reducing the potential for global spread due to agricultural exports from Hawaii.

The role of verbal behavior in the establishment of comparative relations.

Twelve college students received conditional discrimination training with nonarbitrary and arbitrary stimuli, and derived comparative and transformation of function tests with a think-aloud condition across 2 experiments. Participants who failed these tests received remedial verbal operant training. Four control participants received verbal operant training alone. Across both experiments, only 1 participant passed the derived comparative test after conditional discrimination training. However, all participants passed derived comparative tests and 11 out of 12 participants passed transformation of function tests following verbal operant training, including the 4 control participants. Participants who passed derived comparative tests engaged in a high percentage of correct vocalizations during the think-aloud condition, while participants who failed did not. These results suggest that mediating verbal behavior could have played a crucial role in participants' responses during derived stimulus relations tests.

An evaluation of matrix training to teach college students piano notes and rhythms.

Twelve college students learned to tact the names of notes and rhythms and play them when presented with compound stimuli (visuals of notes and rhythms on a musical staff). In Experiment 1, we assessed generalization by presenting novel notes, rhythms, and compound stimuli not previously paired together. In the second experiment, we added a metronome that played at 60 beats per minute in all conditions for 3 out of 6 participants to ensure consistent tempo. Across both experiments, participants passed almost all posttests with the exception of tacting and playing in the presence of sound clips. Our data suggest that matrix training is an effective procedure to teach music skills to college students.

Diagnóstico prenatal de esquizencefalia: caso clínico / Prenatal diagnosis of schizencephalia: clinical case

Se presenta un caso clínico de diagnóstico antenatal de esquizencefalia. En evaluación ultrasonográfica a las 24 semanas se diagnostica esquizencefalia que se corrobora por resonancia nuclear magnética. Se resuelve el embarazo a las 38 semanas por cesárea electiva. El examen ultrasonográfico y la tomografía axial computarizada posnatal confirman el diagnóstico de esquizencefalia. El seguimiento del recién nacido hasta los 3 años muestra un síndrome convulsivo con espasticidad sin repercusión sobre su desarrollo intelectual