Influence of rearing environment on development of perching and dustbathing behaviour in laying hens

Studies have shown that perching and dustbathing behaviour in birds can be affected by how and when the behaviour develops. With the increasing trend away from cages and towards keeping laying hens in larger, more complex housing systems, it is important to improve our knowledge about what chicks need to learn if they are going to be able to fully use perches and litter when these are provided to them as adults. In the first part of this thesis the early use of perches and how this was influenced by the bird´s behaviour during the first weeks of life was investigated at the individual level. Furthermore the relationship between a bird’s spatial ability as a chick and as an adult was investigated by testing birds in two different two-dimensional spatial tests and by observing their use of perches. The aim was to investigate the degree to which birds are hatched with spatial skills or acquire these by using perches. The second part of the thesis dealt with the importance of access to an appropriate, that is to say, functional substrate for the development of dustbathing behaviour. Here comparisons of dustbathing behaviour by birds with different experiences of peat, a preferred dustbathing substrate, were carried out. In addition it was investigated whether birds that had only ever known sham dustbathing would be as motivated to get access to peat for dustbathing as birds reared and used to performing functional dustbathing. It was found that behaviour, such as spending more time underneath the perches, related positively with early perch use and the ability to solve a two dimensional spatial test was related to use of perches in a novel situation as adult. However, the results did not shed any light on whether chicks hatched with good spatial ability or if the spatial ability mostly developed through the use of perches. Dustbathing behaviour was influenced mainly by the substrate and the birds which gained or lost access to peat changed their dustbathing behaviour according to if they dustbathed in peat or on paper. Birds dustbathing on paper performed a less coherent dustbathing behaviour with more long and short bouts than birds dustbathing on peat. Irrespective of treatment all birds were motivated to get access to peat for dustbathing. These results imply that sham dustbathing can not replace functional dustbathing for a hen. In combination, the results of this thesis confirm the importance of giving early access to litter and perches also to the young chick

"Download for Free" - When Do Providers of Digital Goods Offer Free Samples?

In a monopoly setting where consumers cannot observe the quality of the product we show that free samples which are of a lower quality than the marketed digital goods are used together with high prices as signals for a superior quality if the number of informed consumers is small and if the difference between the high and the low quality is not too small. Social welfare is higher, if the monopolist uses also free samples as signals, compared to a situation where he is restricted to pure price signalling. Both, the monopolist and consumers benefit from the additional signal

Anchored in El Sueno Americano

“Give me your tired, give me your poor.” With these words carved into the Statue of Liberty, we should never forget that the United States of America is the home of those fleeing oppression, of those who are brave, and of those who are willing to give their best. [excerpt

"Download for Free" - When Do Providers of Digital Goods Offer Free Samples?

In a monopoly setting where consumers cannot observe the quality of the product we show that free samples which are of a lower quality than the marketed digital goods are used together with high prices as signals for a superior quality if the number of informed consumers is small and if the difference between the high and the low quality is not too small. Social welfare is higher, if the monopolist uses also free samples as signals, compared to a situation where he is restricted to pure price signalling. Both, the monopolist and consumers benefit from the additional signal.Digital Goods; Free Samples; Multi-dimensional Signalling

"Download for Free": When do providers of digital goods offer free samples?

In a monopoly setting where consumers cannot observe the quality of the product we show that free samples which are of a lower quality than the marketed digital goods are used together with high prices as signals for a superior quality if the number of informed consumers is small and if the difference between the high and the low quality is not too small. Social welfare is higher, if the monopolist uses also free samples as signals, compared to a situation where he is restricted to pure price signalling. Both, the monopolist and consumers benefit from the additional signal. --

Automatic Accuracy Prediction for AMR Parsing

Abstract Meaning Representation (AMR) represents sentences as directed, acyclic and rooted graphs, aiming at capturing their meaning in a machine readable format. AMR parsing converts natural language sentences into such graphs. However, evaluating a parser on new data by means of comparison to manually created AMR graphs is very costly. Also, we would like to be able to detect parses of questionable quality, or preferring results of alternative systems by selecting the ones for which we can assess good quality. We propose AMR accuracy prediction as the task of predicting several metrics of correctness for an automatically generated AMR parse - in absence of the corresponding gold parse. We develop a neural end-to-end multi-output regression model and perform three case studies: firstly, we evaluate the model's capacity of predicting AMR parse accuracies and test whether it can reliably assign high scores to gold parses. Secondly, we perform parse selection based on predicted parse accuracies of candidate parses from alternative systems, with the aim of improving overall results. Finally, we predict system ranks for submissions from two AMR shared tasks on the basis of their predicted parse accuracy averages. All experiments are carried out across two different domains and show that our method is effective.Comment: accepted at *SEM 201

Story Cloze Ending Selection Baselines and Data Examination

This paper describes two supervised baseline systems for the Story Cloze Test Shared Task (Mostafazadeh et al., 2016a). We first build a classifier using features based on word embeddings and semantic similarity computation. We further implement a neural LSTM system with different encoding strategies that try to model the relation between the story and the provided endings. Our experiments show that a model using representation features based on average word embedding vectors over the given story words and the candidate ending sentences words, joint with similarity features between the story and candidate ending representations performed better than the neural models. Our best model achieves an accuracy of 72.42, ranking 3rd in the official evaluation.Comment: Submission for the LSDSem 2017 - Linking Models of Lexical, Sentential and Discourse-level Semantics - Shared Tas

An Experimental Digital Library Platform - A Demonstrator Prototype for the DigLib Project at SICS

Within the framework of the Digital Library project at SICS, this thesis describes the implementation of a demonstrator prototype of a digital library (DigLib); an experimental platform integrating several functions in one common interface. It includes descriptions of the structure and formats of the digital library collection, the tailoring of the search engine Dienst, the construction of a keyword extraction tool, and the design and development of the interface. The platform was realised through sicsDAIS, an agent interaction and presentation system, and is to be used for testing and evaluating various tools for information seeking. The platform supports various user interaction strategies by providing: search in bibliographic records (Dienst); an index of keywords (the Keyword Extraction Function (KEF)); and browsing through the hierarchical structure of the collection. KEF was developed for this thesis work, and extracts and presents keywords from Swedish documents. Although based on a comparatively simple algorithm, KEF contributes by supplying a long-felt want in the area of Information Retrieval. Evaluations of the tasks and the interface still remain to be done, but the digital library is very much up and running. By implementing the platform through sicsDAIS, DigLib can deploy additional tools and search engines without interfering with already running modules. If wanted, agents providing other services than SICS can supply, can be plugged in

Ranking and Selecting Multi-Hop Knowledge Paths to Better Predict Human Needs

To make machines better understand sentiments, research needs to move from polarity identification to understanding the reasons that underlie the expression of sentiment. Categorizing the goals or needs of humans is one way to explain the expression of sentiment in text. Humans are good at understanding situations described in natural language and can easily connect them to the character's psychological needs using commonsense knowledge. We present a novel method to extract, rank, filter and select multi-hop relation paths from a commonsense knowledge resource to interpret the expression of sentiment in terms of their underlying human needs. We efficiently integrate the acquired knowledge paths in a neural model that interfaces context representations with knowledge using a gated attention mechanism. We assess the model's performance on a recently published dataset for categorizing human needs. Selectively integrating knowledge paths boosts performance and establishes a new state-of-the-art. Our model offers interpretability through the learned attention map over commonsense knowledge paths. Human evaluation highlights the relevance of the encoded knowledge