Fully flexible analysis of behavioural sequences based on parametric survival models with frailties—A tutorial

Recent automated systems allow collecting continuous data on individual animals with high accuracy over a long time. During this time, animals can be traced across different (discrete) types of behavioural states, with the duration in each state being known. Nevertheless, analyses of such sequences of states or behaviours may prove difficult. Classic Markov-chain methods have limitations in respect to incorporating “memory” (effects of past states), the duration in the states and accounting for dependencies. Dependencies occur in many data sets, where, for example a variety of individuals from different groups are observed and/or when an experiment is divided in different crossover treatment phases. So-called parametric survival analysis with frailties can incorporate aforementioned aspects in one coherent model. The time spent in a specific state (performing a specific behaviour) can be modelled in dependence of the subsequent state (transition probabilities) while incorporating how these transitions are influenced by experimental treatments. In addition, prior states can be used as predictor variables (accounting for past behaviour). Finally, random effects can be included to account for dependencies according to, for example individual identity, group/farm/laboratory or experimental period. Using interactions between random and fixed effects, the within- and between-subject variability of the transition probabilities can be estimated to indicate variation between and consistency within individual subjects (individuality and personality). Moreover, relative hazards describing transitions from one state to several potential follow-up states can be estimated. Behavioural sequences and their modulation by experimental situations can be studied accordingly. Using two exemplary data sets, the data type and structure adequate for parametric survival analysis are introduced and advice is given on how to specify and run such models. Overall, parametric survival analysis with frailties presents a modern and versatile approach that can revive sequential analysis. This will facilitate more detailed use of behavioural data and accordingly detect more subtle aspects of behaviour.Ministerie van Economische Zaken en Klimaat http://dx.doi.org/10.13039/501100016238Bundesamt für Lebensmittelsicherheit und Veterinärwesen http://dx.doi.org/10.13039/501100006454Peer Reviewe

Teelt van biomassa niet rendabel

Op verschillende locaties in Nederland werd gedurende de jaren 1993-1999 onderzoek gedaan naar de geschiktheid van miscanthus en hennep als akkerbouwmatig geteeld energiegewas. De resultaten wat betreft gewasproductiviteit (biomassa-opbrengst) bij verschillende stikstofbemestingsniveaus en plantdichtheden, de minerale samenstelling en minerale behoeften van het gewas, gewasopkomst en gewasvestiging bij variërende plantleeftijd, poottijd en rhizoomgrootte (voor miscanthus), en voor beide gewassen de economische perspectieven. Ondanks goede opbrengsten kan het saldo niet tippen aan het gemiddelde van de gewassen in een normaal bouwplan; ook hier zijn weer subsidies nodi

Extraction of state machines of legacy C code with Cpp2XMI

Analysis of legacy code is often focussed on extracting either metrics or relations, e.g. call relations or structure relations. For object-oriented programs, e.g. Java or C++ code, such relations are commonly represented as UML diagrams: e.g., such tools as Columbus [1] and Cpp2XMI [2] are capable of extracting from the C++ code UML class, and UML class, sequence and activity diagrams, respectively. New challenges in UML diagram extraction arise when a) additional UML diagrams and b) non-object-oriented programs are considered. In this paper we present an ongoing work on extracting state machines from the legacy C code, motivated by the popularity of state machine models in embedded software [3]. To validate the approach we consider an approximately ten-years old embedded system provided by the industrial partner. The system lacks up-to-date documentation and is reportedly hard to maintain

A Virtual Conversational Agent for Teens with Autism: Experimental Results and Design Lessons

We present the design of an online social skills development interface for teenagers with autism spectrum disorder (ASD). The interface is intended to enable private conversation practice anywhere, anytime using a web-browser. Users converse informally with a virtual agent, receiving feedback on nonverbal cues in real-time, and summary feedback. The prototype was developed in consultation with an expert UX designer, two psychologists, and a pediatrician. Using the data from 47 individuals, feedback and dialogue generation were automated using a hidden Markov model and a schema-driven dialogue manager capable of handling multi-topic conversations. We conducted a study with nine high-functioning ASD teenagers. Through a thematic analysis of post-experiment interviews, identified several key design considerations, notably: 1) Users should be fully briefed at the outset about the purpose and limitations of the system, to avoid unrealistic expectations. 2) An interface should incorporate positive acknowledgment of behavior change. 3) Realistic appearance of a virtual agent and responsiveness are important in engaging users. 4) Conversation personalization, for instance in prompting laconic users for more input and reciprocal questions, would help the teenagers engage for longer terms and increase the system's utility

Actualiteiten Varkensproefbedrijf Sterksel

- Perspectieven buisvoerbakken voor gespeende - biggen en vleesvarkens - Emissie-arme huisvesting bij grote groepen gespeende bigge

Emissie-arm huisvesten van grote koppels gespeende biggen is goed mogelijk

Uit onderzoek op het Varkensproefbedrijf te Sterksel blijkt dat emissie-arme huisvesting van grote koppels gespeende biggen op een eenvoudige manier mogelijk is. In één afdeling werd een water- en mestkanaal toegepast, terwijl de andere afdeling uitgerust was met een gedeeltelijk roostervloer in combinatie met schuine putwanden in het mestkanaal

Nieuw goed koop emissie-arm systeem bij vleesvarkens

Het monteren van schuine wanden in de mestkanalen van een vleesvarkensafdeling (optimaal hok) verkleint het emitterend oppervlak zodanig, dat de ammoniakemissie gereduceerd wordt tot 1,0 kg NH3 per dierplaats per jaa