Maintaining rear-fanged snakes for venom production: an evaluation of mortality and survival rates for Philodryas olfersii and P. patagoniensis in captivity

This study evaluates the mortality and average survival rates of captive female Philodryas olfersii and Philodryas patagoniensis snakes maintained for venom production. Also, two factors likely to reduce captive survival were studied - body condition at admission and seasonality. Mortality peaks occurred during the second month in captivity. More than half the individuals were dead at the end of the third month. This suggests that the first three months in captivity are the most critical in terms of survival and adaptation. Females collected and admitted during spring and summer lived less time than those collected in autumn and winter. As gravidity and egg-laying occur during spring and summer, we suggest that the lower survival rates in these seasons may be due to high costs and stress involved in these reproductive events. Unexpectedly, body mass and body condition were poor predictors of survival in captivity. Our results have important implications in maintaining snakes for venom production. We propose some prophylactic measures to minimize the deleterious impacts of captivity during the adaptation period

Confluent Orthogonal Drawings of Syntax Diagrams

We provide a pipeline for generating syntax diagrams (also called railroad diagrams) from context free grammars. Syntax diagrams are a graphical representation of a context free language, which we formalize abstractly as a set of mutually recursive nondeterministic finite automata and draw by combining elements from the confluent drawing, layered drawing, and smooth orthogonal drawing styles. Within our pipeline we introduce several heuristics that modify the grammar but preserve the language, improving the aesthetics of the final drawing.Comment: GD 201

Molecular identification of a retinal cell type that responds to upward motion

The retina contains complex circuits of neurons that extract salient information from visual inputs. Signals from photoreceptors are processed by retinal interneurons, integrated by retinal ganglion cells (RGCs) and sent to the brain by RGC axons. Distinct types of RGC respond to different visual features, such as increases or decreases in light intensity (ON and OFF cells, respectively), colour or moving objects1, 2, 3, 4, 5. Thus, RGCs comprise a set of parallel pathways from the eye to the brain. The identification of molecular markers for RGC subsets will facilitate attempts to correlate their structure with their function, assess their synaptic inputs and targets, and study their diversification. Here we show, by means of a transgenic marking method, that junctional adhesion molecule B (JAM-B) marks a previously unrecognized class of OFF RGCs in mice. These cells have asymmetric dendritic arbors aligned in a dorsal-to-ventral direction across the retina. Their receptive fields are also asymmetric and respond selectively to stimuli moving in a soma-to-dendrite direction; because the lens reverses the image of the world on the retina, these cells detect upward motion in the visual field. Thus, JAM-B identifies a unique population of RGCs in which structure corresponds remarkably to function

Segmento tardio do desempenho em linguagem de crianças com desvio fonológico após terapia fonológica Late follow-up of language performance of children with phonological disorders after speech therapy

OBJETIVO: Realizar um acompanhamento tardio do desempenho em habilidades de linguagem de um grupo de estudo com histórico de desvio fonológico (após ter realizado terapia fonológica), comparando-o com um grupo controle. MÉTODOS: Dezoito sujeitos, nove do grupo de estudo e nove do controle, participaram do estudo e foram avaliados quanto à linguagem escrita a partir da aplicação de atividades de compreensão de texto, complementação de sentenças, formação de sentenças, sequencialização de parágrafos e combinação de sentenças que fazem parte do Exame de Linguagem TIPITI. RESULTADOS: Os resultados da pesquisa mostraram correlações estatísticas significantes, positivas e fortes, nas habilidades de linguagem, entre os grupos estudados e, também, diferenças estatisticamente significantes entre o grupo experimental e o grupo controle, na análise do teste Kruskal-Wallis. CONCLUSÃO: Verificou-se que, mesmo após a realização de terapia fonológica e a superação dos desvios, o grupo de estudo apresentou desempenho inferior ao do grupo controle.<br>PURPOSE: To carry out a late follow-up of the performance on language abilities of a study group with history of phonological disorders (after speech therapy), compared to a control group with normal phonological development. METHODS: Eighteen subjects, nine from the study group and nine from the control group, participated in the study and were evaluated on written language, carrying out tasks of text comprehension, sentences complementation, sentences formation, paragraph continuation, and sentences combination, which are part of the TIPITI Language Assessment. RESULTS: The results showed positive and strong statistically significant correlation between the groups regarding the language abilities. Statistically significant differences were also found between study and control groups on the Kruskal-Wallis test. CONCLUSION: It was verified that, even after speech therapy and overcoming speech disorders, the study group showed lower performance on language tasks when compared to the control group