Product Recommendations in E-commerce Systems using Content-based Clustering and Collaborative Filtering

In this report we take a new approach to product recommendation. We investigate the the possibility of using a hybrid recommender consisting of contentbased clustering and connections between clusters using collaborative filtering to make good product recommendations. The algorithm is tested on real product and purchase data from two different companies - a big online book store and a smaller online clothing store. It is evaluated both for functionality as a backfiller to other algorithms and as a strong individual algorithm. The evaluation mainly looks at the number of purchases as metric but also uses accuracy and recall as evaluation metrics. The algorithm shows some promise for using it as an individual algorithm

Mångfaldens enfald - En diskursanalys med utgångspunkt i city branding av mångfaldsbegreppet i Malmö stads kommunikation

City branding consists of the complicated task to communicate an entire city as one single brand. The city brand must satisfy the inhabitants’need to feel a sense of belonging without risking excluding outsiders. The choice of words of value must reflect the population’s characteristics, variations and capacities and at the same time be communicated consistently and coherently to stakeholders. Malmö has chosen to integrate the word "diversity" in their municipality slogan - a word that in itself might be interpreted in various ways. The paper centers around a discourse analysis of the word “diversity” and what meaning the word ”diversity” acquires in Malmö’s communication and how this co-relates to city branding. The analysis showed that the word “diversity” was given different types of meaning depending on the context. In abstract contexts, in a discourse of success, the word had including and positive connotations. In substantial, concrete contexts – in a discourse of problems – the word “diversity” came to be excluding and restricted to embody solely ethnic diversity. The analysis also found that the word ”diversity” can be interpreted either as an actuality or as something that must be accomplished. Therefore might the word “diversity” be the closest we can get to unite the contradicting ground principles in city branding: to create a brand that must be realistic and representative as well as desirable and attractive. The work regarding this examination paper has been divided evenly between the two co-writers.City branding består av den tunga uppgiften att marknadsföra en hel stad under ett enda varumärke. Stadsvarumärket måste tillfredsställa invånarnas behov av samhörighet utan att exkludera utomstående. Valet av värdeord måste återspegla populationens variationer och egenskaper samtidigt som det måste kommuniceras konsekvent och enhetligt till intressenter. Malmö stad har valt att i sin kommunslogan integrera begreppet ”mångfald” - ett begrepp som i sig självt inbegriper ett omfattande tolkningsutrymme. Uppsatsen centreras kring en diskursanalys av mångfaldsbegreppet som söker svar på frågorna om vilken betydelse begreppet mångfald ges i Malmö stads kommunikation och hur det korrelerar med city branding. Analysen fann att mångfaldsbegreppet gavs olika innebörd i abstrakta respektive konkreta kontexter: där begreppet fungerade som inkluderande och positivt i en abstrakt framgångsdiskurs men exkluderande och begränsat till etnisk mångfald i en konkret problemdiskurs. Vidare fann analysen att mångfald kan tolkas antingen som något som “bara är” eller som något som bör uppnås. Mångfaldsbegreppet blir därför måhända det närmaste man kan komma att förena de motsägelsefulla grundprinciperna i city branding: att ett varumärke som måste vara representativt och verkligt samtidigt som det måste vara önskvärt och tydligt. Arbetet kring detta examensarbete har till lika stora delar utförts av båda författarna

Neuronal Processing of Complex Mixtures Establishes a Unique Odor Representation in the Moth Antennal Lobe

Animals typically perceive natural odor cues in their olfactory environment as a complex mixture of chemically diverse components. In insects, the initial representation of an odor mixture occurs in the first olfactory center of the brain, the antennal lobe (AL). The contribution of single neurons to the processing of complex mixtures in insects, and in particular moths, is still largely unknown. Using a novel multicomponent stimulus system to equilibrate component and mixture concentrations according to vapor pressure, we performed intracellular recordings of projection and interneurons in an attempt to quantitatively characterize mixture representation and integration properties of single AL neurons in the moth. We found that the fine spatiotemporal representation of 2–7 component mixtures among single neurons in the AL revealed a highly combinatorial, non-linear process for coding host mixtures presumably shaped by the AL network: 82% of mixture responding projection neurons and local interneurons showed non-linear spike frequencies in response to a defined host odor mixture, exhibiting an array of interactions including suppression, hypoadditivity, and synergism. Our results indicate that odor mixtures are represented by each cell as a unique combinatorial representation, and there is no general rule by which the network computes the mixture in comparison to single components. On the single neuron level, we show that those differences manifest in a variety of parameters, including the spatial location, frequency, latency, and temporal pattern of the response kinetics

Sommarmellangrödors ogräsbekämpande egenskaper - resultat från två fältförsök 2016

Under 2016 genomfördes två fältförsök med fokus på olika sommarmellangrödors ogräsbekämpande egenskaper samt dess biomassaproduktion. Ett av försöken var placerat på Norra Åsum vid Kristianstad i Skåne och det andra på Lilla Böslid vid Laholm i Halland. De sommarmellangrödor som hade bäst ogräskonkurrerande egenskaper på de båda försöksplatserna var oljerättika, facelia och bovete, medan sudangräset var sämst på att konkurrera med ogräset. På Norra Åsum hade även hampa samt hampa i samodling med luddvicker lika bra ogräskonkurrerande effekt som oljerättika, facelia och bovete. Hälften av parcellerna gödslades med kväve på båda försöksplatserna. På Norra Åsum var det generellt fler ogräs i de gödslade leden. Förhållandet var det motsatta på Lilla Böslid där ogräsfloran dominerades av åkerspergel. I de gödslade leden på Norra Åsum fanns det ett svagt samband mellan ogräsets torrvikt och sommarmellangrödornas torrvikt. Ju större sommarmellangrödans biomassa var desto lägre blev ogräsvikten. Sommarmellangrödorna, som alla såddes den 20 juli på Norra Åsum, gav största skörden då de skördades den 13 oktober (85 dagars kulturtid). Sudangräs i kombination med luddvicker gav dock en större skörd den 7 november (110 dagars kulturtid). I de gödslade leden på Norra Åsum med 41 kg ammoniumkväve per ha i form av biogödsel (rötrest) gav hampa den signifikant högsta mängden biomassa (4,2 ton ts/ha), medan gödslat sudangräs resp. bovete gav den lägsta biomassan (2,9 ton ts/ha) i mitten av oktober. Gödslad oljerättika jämfört med ogödslad oljerättika ökade skörden 2,3 gånger, från 1,4 till 3,3 ton ts/ha. I de ogödslade leden gav hampa i kombination med luddvicker den signifikant högsta skörden (3,8 ton ts/ha). Slutsatsen från försöken under 2016 med sommarmellangrödors ogräsbekämpande egenskaper är följande: Oljerättika, facelia, bovete och hampa samt hampa i kombination med luddvicker har förutsättningar att konkurrera bra mot ogräs på lättare sandjord. Detta under förutsättning att mellangrödorna etablerar sig bra och att de har en god tillväxt under sommaren och hösten. Gödsling av sommarmellangrödorna med ca 40 resp. ca 50 kg kväve per ha resulterade generellt i fler ogräs på Norra Åsum, och färre på Lilla Böslid där ogräsfloran dominerades av åkerspergel. Detta resultat visar att ytterligare försök med sommarmellangrödors ogräskonkurrerande egenskaper behöver genomföras för att fastslå gödslingens påverkan på ogräseffekten och mellangrödans biomassaproduktion under olika årsmåner, markförhållanden etc

Influence of ghrelin on the central serotonergic signaling system in mice

AbstractThe central ghrelin signaling system engages key pathways of importance for feeding control, recently shown to include those engaged in anxiety-like behavior in rodents. Here we sought to determine whether ghrelin impacts on the central serotonin system, which has an important role in anxiety. We focused on two brain areas, the amygdala (of importance for the mediation of fear and anxiety) and the dorsal raphe (i.e. the site of origin of major afferent serotonin pathways, including those that project to the amygdala). In these brain areas, we measured serotonergic turnover (using HPLC) and the mRNA expression of a number of serotonin-related genes (using real-time PCR). We found that acute central administration of ghrelin to mice increased the serotonergic turnover in the amygdala. It also increased the mRNA expression of a number of serotonin receptors, both in the amygdala and in the dorsal raphe. Studies in ghrelin receptor (GHS-R1A) knock-out mice showed a decreased mRNA expression of serotonergic receptors in both the amygdala and the dorsal raphe, relative to their wild-type littermates. We conclude that the central serotonin system is a target for ghrelin, providing a candidate neurochemical substrate of importance for ghrelin's effects on mood

Integrating multiple dimensions of ecological stability into a vulnerability framework

Ecological stability encompasses multiple dimensions of functional and compositional responses to environmental change. Though no single stability dimension used in isolation can fully reflect the overall response to environmental change, a common vulnerability assessment that integrates simultaneously across multiple stability components is highly desirable for ecological risk assessment. We develop both functional and compositional counterparts of a novel, integrative metric of overall ecological vulnerability (OEV). We test the framework with data from a modularized experiment replicated in five lakes over two seasons, examining functional and compositional responses to both pulse and press disturbances across three trophic groups. OEV is measured as the area under the curve integrated over the entire observation period, with the curve delimiting the difference between the disturbance treatment and undisturbed parallel controls, expressed either as the log response ratio of biomass (functional OEV) or community dissimilarity index (compositional OEV). Both, functional and compositional OEV correlated negatively with functional and compositional 'resistance', 'temporal stability' and 'final/extent of recovery' following both pulse and press disturbances, though less so with 'resilience' following a pulse disturbance. We also found a positive correlation between functional and compositional OEV, which reveals the potential to also evaluate the intricate linkage between biodiversity and functional change. Our findings demonstrate that OEV comprises a robust framework to: (a) capture simultaneously multiple functional and compositional stability components, and (b) quantify the functional consequences of biodiversity change. Our results provide the basis for an overarching framework for quantifying the overall vulnerability of ecosystems to environmental change, opening new possibilities for ecological risk assessment and management. Synthesis. Ecological stability comprises multiple dimensions that together encapsulate how ecosystems respond to environmental change. Considering these multiple aspects of stability simultaneously often poses a problem in environmental assessments, which frequently require overarching indicators of risk or vulnerability. While an analysis of multiple dimensions allows for deeper exploration of mechanisms, here we develop and test a new univariate indicator that integrates stability aspects under a broad range of disturbance regimes. Using a modularized experiment in Swedish lakes, we show that this integrative measure captures multiple stability dimensions reflecting compositional and functional vulnerability and their relationships between them

Long working hours, anthropometry, lung function, blood pressure and blood-based biomarkers: Cross-sectional findings from the CONSTANCES study

Background Although long working hours have been shown to be associated with the onset of cardiometabolic diseases, the clinical risk factor profile associated with long working hours remains unclear. We compared the clinical risk profile between people who worked long hours and those who reported being never exposed to long hours.Methods A cross-sectional study in 22 health screening centres in France was based on a random population-based sample of 75 709 participants aged 18–69 at study inception in 2012–2016 (the CONSTANCES study). The data included survey responses on working hours (never, former or current exposure to long working hours), covariates and standardised biomedical examinations including anthropometry, lung function, blood pressure and standard blood-based biomarkers.Results Among men, long working hours were associated with higher anthropometric markers (Body Mass Index, waist circumference and waist:hip ratio), adverse lipid levels, higher glucose, creatinine, white blood cells and higher alanine transaminase (adjusted mean differences in the standardised scale between the exposed and unexposed 0.02–0.12). The largest differences were found for Body Mass Index and waist circumference. A dose–response pattern with increasing years of working long hours was found for anthropometric markers, total cholesterol, glucose and gamma-glutamyltransferase. Among women, long working hours were associated with Body Mass Index and white blood cells.Conclusion In this study, men who worked long hours had slightly worse cardiometabolic and inflammatory profile than those who did not work long hours, especially with regard to anthropometric markers. In women, the corresponding associations were weak or absent.</div

Capability in research on cognition and well-being in ageing and retirement

In this chapter, we outline our thoughts on capability in relation to previous and ongoing research projects conducted by the Adult Development and Ageing (ADA-Gero) Research Group located at the Department of Psychology, University of Gothenburg, Sweden. More specifically, we relate our research on cognitive ageing and subjective well-being to the overarching capability framework implemented as a theoretical platform in the AgeCap research consortium