Open-source, Python-based, hardware and software for controlling behavioural neuroscience experiments

Laboratory behavioural tasks are an essential research tool. As questions asked of behaviour and brain activity become more sophisticated, the ability to specify and run richly structured tasks becomes more important. An increasing focus on reproducibility also necessitates accurate communication of task logic to other researchers. To these ends, we developed pyControl, a system of open-source hardware and software for controlling behavioural experiments comprising a simple yet flexible Python-based syntax for specifying tasks as extended state machines, hardware modules for building behavioural setups, and a graphical user interface designed for efficiently running high-throughput experiments on many setups in parallel, all with extensive online documentation. These tools make it quicker, easier, and cheaper to implement rich behavioural tasks at scale. As important, pyControl facilitates communication and reproducibility of behavioural experiments through a highly readable task definition syntax and self-documenting features. Here, we outline the system’s design and rationale, present validation experiments characterising system performance, and demonstrate example applications in freely moving and head-fixed mouse behaviour

Development of national feed inventory and feeding interventions to enhance livestock productivity in India

Presentation prepared to the FAP Symposium on Feed in Smallholder Systems, Luang Prabang, Laos, 18-19 November 2010

Alimentação de bezerros ruminantes com dieta líquida, via goteira esofageana: parâmetros ruminais Ruminant calves feeding with liquid diet, through esophageal groove: ruminal parameters

Efeitos de fornecer proteína texturizada de soja (PTS) na forma líquida, via goteira esofágica, ou na forma sólida, via concentrados, foram estudados em um delineamento quadrado latino 4 x 4, empregando quatro novilhos Holandeses providos de cânulas ruminais, pesando cerca de 100 kg cada, no início do experimento. Os tratamentos consistiram de níveis crescentes de PTS na forma líquida (0, 33, 66 e 100%), oferecidos em mamadeiras, e níveis decrescentes de misturas concentradas, mantendo-se a mesma quantidade de nitrogênio em todas as dietas. Os subperíodos experimentais foram de 21 dias, sendo os primeiros 16 de adaptação às rações (feno de Cynodon dactilon, mistura concentrada e alimento líquido). Ensaio de digestibilidade in situ foi executado do dia 17 ao 20, sendo os tempos de incubação de 0, 1,5, 3, 6, 12, 24 e 48 horas, para o farelo de soja e PTS, e 0, 6, 12, 24, 48h, 72 e 96 horas para o feno. Foram tomadas amostras de conteúdo ruminal para análise de volume e taxa de passagem de líquidos, e pH, no dia 21 às 0, 1, 3, 6, 12 e 24 horas. No dia 20, conteúdos ruminais foram coletados para análise de ácidos graxos voláteis (AGV) e N amoniacal às 0, 2, 4, 5 e 6h após a primeira alimentação do dia. Foi observado aumento na taxa de passagem e turnover líquido com a diminuição do suplemento protéico na forma líquida. Não ocorreram efeitos da forma de alimentação nas concentrações dos totais de AGV ou nas suas porcentagens molares individuais, do mesmo modo que o pH não foi afetado. Não houve efeitos da forma de alimentação sobre a degradabilidade in situ da proteína e da matéria seca do farelo de soja e PTS, tampouco efeitos sobre a degradabilidade da matéria seca e fibra em detergente neutro do feno.<br>Effects of feeding textured soy protein (TSP), in liquid form throught esophageal groove, or solid form throught concentrate meal, were studied in a 4 x 4 Latin-square change-over design, using four Holstein steers fitted with ruminal cannulas, averaging 100 kg live weight at the beginning of trial. Treatments consisted of increasing TSP levels in liquid form (0, 33, 66 and 100%) offered through nipple-pail, and decreasing levels in concentrate meal to keep the same amout of nitrogen in all diets. Twenty-one days sub periods were used, the first sexteen for diet adaptation (Cynodon dactilon hay, concentrate mixture and liquid feed). In situ degradability assay was runned from day 17 to 20, and incubation times were 0, 1.5, 3, 6, 12, 24 and 48hours for soybean meal and TSP, and 0, 6, 12, 24, 48, 72 and 96 hours for coastcross hay. Ruminal contents colections to analize liquid volume, passage rate, and pH were made at twentieth first day at 0h, 1h, 3h, 6h, 12h, and 24h. On twentieth day ruminal contents were colected to analyze volatile fatty acids (VFA) and ammonia nitrogen at 0, 2h, 3h, 4h, 5h and 6h after first feed. An increase in passage rate and ruminal turnover was observed as the liquid suplement protein amount decreased. There were no effects of feeding form in the total VFA concentrations or its individual molar percentages; also ruminal pH was not affected. There were no effects of feeding form upon in situ degradability of soybean meal and TSP dry matter (DM) and crude protein (CP), as well as there were no effects in the degradability of Coast-Cross hay DM and neutral detergent fiber (NDF)