An Optically Stabilized Fast-Switching Light Emitting Diode as a Light Source for Functional Neuroimaging

Neuroscience research increasingly relies on optical methods for evoking neuronal activity as well as for measuring it, making bright and stable light sources critical building blocks of modern experimental setups. This paper presents a method to control the brightness of a high-power light emitting diode (LED) light source to an unprecedented level of stability. By continuously monitoring the actual light output of the LED with a photodiode and feeding the result back to the LED's driver by way of a proportional-integral controller, drift was reduced to as little as 0.007% per hour over a 12-h period, and short-term fluctuations to 0.005% root-mean-square over 10 seconds. The LED can be switched on and off completely within 100 µs, a feature that is crucial when visual stimuli and light for optical recording need to be interleaved to obtain artifact-free recordings. The utility of the system is demonstrated by recording visual responses in the central nervous system of the medicinal leech Hirudo verbana using voltage-sensitive dyes

Suckling systems in calf rearing in organic dairy farming in the Netherlands

In an on-farm experiment three calf rearing methods were compared: bucket feeding of milk replacer, bucket feeding of tank milk and suckling of mother or nurse cow up to three months of age. Aim was to determine whether the technical results of suckling systems in calf rearing were satisfactory. Calves reared in a suckling system reached significantly higher liveweights at weaning (90 days). Although the average growth rate between weaning and the age of 1 year did not differ significantly, liveweight at 1 year did still differ significantly. Compared to both bucket fed rearing groups, suckling did not have a significant effect on Somatic Cell Count (SCC) of mothers. Suckling systems in calf rearing in organic dairy production show satisfactory technical results. Calves have the potential to grow fast and no negative effect of suckling on SCC or general animal health were observed

Effect of State Coalitions to Reduce Underage Drinking: A National Evaluation

Summarizes an evaluation of how the RWJF-funded Reducing Underage Drinking Through Coalitions Project to reduce youth drinking changed media coverage of alcohol-related issues, state policy, youth drinking behaviors, and alcohol-related driving behaviors

Farm level factors associated with feather pecking in organic laying hens

Farm-level factors that could be associated with feather pecking of layers kept in organic farming systems were monitored in 63 flocks from 26 farms located in different areas of The Netherlands. Data on housing and management practices were collected and plumage damage as a measure of feather pecking was scored at 50 weeks of age or older. No or little plumage damage was found in 18 (29%) flocks, moderate damage in 12 (19%) flocks and severe damage in 33 (52%) flocks. A high percentage of hens in the flock using the outdoor run, a young age at purchase and an increasing number of cockerels present in the flock were found to significantly decrease feather pecking damage at 50 weeks or older. Factors associated with increased usage of the outdoor run were smaller flock size, a young age at purchase, an increasing number of cockerels present in the flock and a higher percentage of cover in the run. Based on the results organic farmers are likely to benefit from rearing their own layers. They should keep cockerels with their layers. Other practices resulting in low feather pecking damage are stimulating the use of the outdoor run by making it attractive with vegetative or artificial cover or keeping the flock size at around 500 birds

Practical implications of increasing 'natural living' through suckling systems in organic dairy calf rearing

The introduction of suckling systems in organic dairy calf rearing has the potential to enhance animal welfare in terms of ‘natural living’ and to live up to consumers’ expectations about organic agriculture. This study describes the implications of suckling systems in a practical organic dairy context. Results show that farmers can successfully develop and implement a suckling system in calf rearing. The consumption of mothers’ milk resulted in high weaning weights at 3 months of age. No immediate animal health problems linked to suckling systems occurred. Compared with traditional bucket feeding of milk, suckling systems resulted in increased natural behaviour such as calf cow bonding, natural sucking behaviour and care-taking behaviour. Some farmers had difficulties accepting negative implications of suckling systems such as stress after weaning and loss of marketable milk. Although suckling of the own mother was seen as the most natural suckling system, farmers adapted their suckling system to calves suckling nurse cows. In order to implement successfully a suckling system, farmers have to step back from control and give calf and cow a chance. In the case of increasing ‘natural living’ through implementation of a suckling system, farmers should be encouraged to take enough time to accomplish this attitude change

Suckling as an alternative rearing system for replacement calves on dairy farms

The aim is to develop an alternative calf rearing system for replacement calves that will improve animal welfare on dairy farms and meets the requirements of farmers in terms of practicality and cost. On the dairy farms that make use of a suckling system are calves suckled by their mother or a nurse cow, for a duration that ranges from three days up to three months. Compared to artificial calf rearing, suckling systems are beneficial to the welfare of calves. The calves will be nursed by their mother, suckled with milk, learn to eat roughage at a younger age, have social contact with other calves and cows and have space enough to exercise and play

Experiential science as a novel scientific discipline

This report was presented at the UK Organic Research 2002 Conference. This paper positions experiential science as a new discipline in science with its own characteristics and principles. New elements in experiential science are the recognition of unique patterns in relation to previous actions and the reflection on intuitive, unique actions. There is a need for a new vocabulary to develop experiential science as a novel discipline

Influence of chance, history, and adaptation on digital evolution

We evolved multiple clones of populations of digital organisms to study the effects of chance, history, and adaptation in evolution. We show that clones adapted to a specific environment can adapt to new environments quickly and efficiently, although their history remains a significant factor in their fitness. Adaptation is most significant (and the effects of history less so) if the old and new environments are dissimilar. For more similar environments, adaptation is slower while history is more prominent. For both similar and dissimilar transfer environments, populations quickly lose the ability to perform computations (the analogue of beneficial chemical reactions) that are no longer rewarded in the new environment. Populations that developed few computational "genes" in their original environment were unable to acquire them in the new environment

International training and exchange – a useful instrument in knowledge and attitude dissemination

Knowledge about organic agriculture is constantly changing and growing. Research related to organic agriculture at EU level nowadays plays an important role. Organic agriculture, being an integrated, holistic and multi-target approach, needs researchers who are trained to investigate poly-factorial and multi-level problems. For students and junior scientists, international seminars and exchange programs are necessary instruments to gain “state of the art” knowledge and skills from senior scientists in the field of organic agriculture. The QLIF training programme under WP7.4 provides training in the different aspects of ecological farming systems, but also offers an opportunity to discuss relevant and adequate research strategies and results. Within the EU sixth framework QLIF project, so far two seminars have been organized. Contents and impact of these seminars are discussed

Suckling systems in calf rearing in organic dairy farming in the Netherlands

In an on-farm experiment three calf rearing methods were compared: bucket feeding of milk replacer, bucket feeding of tank milk and suckling of mother or nurse cow up to three months of age. Aim was to determine whether the technical results of suckling systems in calf rearing were satisfactory. Calves reared in a suckling system reached significantly higher liveweights at weaning (90 days). Although the average growth rate between weaning and the age of 1 year did not differ significantly, liveweight at 1 year did still differ significantly. Compared to both bucket fed rearing groups, suckling did not have a significant effect on Somatic Cell Count (SCC) of mothers. Suckling systems in calf rearing in organic dairy production show satisfactory technical results. Calves have the potential to grow fast and no negative effect of suckling on SCC or general animal health were observed