Contextual Model-Based Collaborative Filtering for Recommender Systems

Recommender systems have dramatically changed the way we consume content. Internet applications rely on these systems to help users navigate among the ever-increasing number of choices available. However, most current systems ignore that user preferences can change according to context, resulting in recommendations that do not fit user interests. Context-aware models have been proposed to address this issue, but these models have problems of their own. The ever-increasing speed at which data are generated presents a scalability challenge for single-model approaches. Moreover, the complexity of these models prevents small players from adapting and implementing contextual models that meet their needs. This thesis addresses these issues by proposing the (CF)2 architecture, which uses local learning techniques to embed contextual awareness into collaborative filtering (CF) models. CF has been available for decades, and its methods and benefits have been extensively discussed and implemented. Moreover, the use of context as filtering criteria for local learning addresses the scalability issues caused by the use of large datasets. Therefore, the proposed architecture enables the creation of contextual recommendations using several models instead of one, with each model representing a context. In addition, the architecture is implemented and evaluated in two case studies. Results show that contextual models trained with a small fraction of the data resulted in similar or better accuracy compared to CF models trained with the total dataset. Moreover, experiments indicate that local learning using contextual information outperforms random selection in accuracy and in training time

The Vocation of the Missionary

https://place.asburyseminary.edu/firstfruitspapers/1111/thumbnail.jp

State of Harmonization of 24 Serum Albumin Measurement Procedures and Implications for Medical Decisions

BACKGROUND: Measurements of serum and plasma albumin are widely used in medicine, including as indicators of quality of patient care in renal dialysis centers. METHODS: Pools were prepared from residual patient serum (n = 50) and heparin plasma (n = 48) from patients without renal disease, and serum from patients with kidney failure before hemodialysis (n = 53). Albumin was measured in all samples and in ERM-DA470k/IFCC reference material (RM) by 3 immunochemical, 9 bromcresol green (BCG), and 12 bromcresol purple (BCP) methods. RESULTS: Two of 3 immunochemical procedures, 5 of 9 BCG, and 10 of 12 BCP methods recovered the RM value within its uncertainty. One immunochemical and 3 BCG methods were biased vs the RM value. Random error components were small for all measurement procedures. The Tina-quant immunochemical method was chosen as the reference measurement procedure based on recovery and results of error analyses. Mean biases for BCG vs Tina-quant were 1.5% to 13.9% and were larger at lower albumin concentrations. BCP methods\u27 mean biases were -5.4% to 1.2% irrespective of albumin concentration. Biases for plasma samples were generally higher than for serum samples for all method types. For most measurement procedures, biases were lower for serum from patients on hemodialysis vs patients without kidney disease. CONCLUSIONS: Significant differences among immunochemical, BCG, and BCP methods compromise interpretation of serum. albumin results. Guidelines and calculations for clinical management of kidney and other diseases must consider the method used for albumin measurement until harmonization can be achieved

Conformational Mechanics of Polymer Adsorption Transitions at Attractive Substrates

Conformational phases of a semiflexible off-lattice homopolymer model near an attractive substrate are investigated by means of multicanonical computer simulations. In our polymer-substrate model, nonbonded pairs of monomers as well as monomers and the substrate interact via attractive van der Waals forces. To characterize conformational phases of this hybrid system, we analyze thermal fluctuations of energetic and structural quantities, as well as adequate docking parameters. Introducing a solvent parameter related to the strength of the surface attraction, we construct and discuss the solubility-temperature phase diagram. Apart from the main phases of adsorbed and desorbed conformations, we identify several other phase transitions such as the freezing transition between energy-dominated crystalline low-temperature structures and globular entropy-dominated conformations.Comment: 13 pages, 15 figure

Microcanonical entropy inflection points: Key to systematic understanding of transitions in finite systems

We introduce a systematic classification method for the analogs of phase transitions in finite systems. This completely general analysis, which is applicable to any physical system and extends towards the thermodynamic limit, is based on the microcanonical entropy and its energetic derivative, the inverse caloric temperature. Inflection points of this quantity signal cooperative activity and thus serve as distinct indicators of transitions. We demonstrate the power of this method through application to the long-standing problem of liquid-solid transitions in elastic, flexible homopolymers.Comment: 4 pages, 3 figure

Pull and Push'- Implementing the Complementarity Principle of the Rome Statute of the ICC within the AU: Opportunities and Challenges

The complementarity principle of the Rome Statute of the International Criminal Court (ICC) is an international legal principle that governs the relationship between two; sometimes; contrasting international principles of law; namely sovereign equality of States and the international community’s duty to end impunity for international core crimes. Article 17 of the Rome Statute envisages that States maintain primary jurisdiction to investigate and prosecute international crimes; while the ICC’s jurisdiction to prosecute when States are unwilling or genuinely unable to carry out such investigations or prosecutions constitutes the exception. This article provides an analysis of this principle in the context of the institutional; normative; and policy framework for its domestic implementation within the African national legal orders. This article contends that at times of increasing tensions between the African Union (AU) and the ICC; AU States signatory to the ICC must become proactive in terms of furthering their commitments to fully cooperate with the ICC and the international community. Building on the evidence in literature; this article elaborates on how complementarity can ideally function in practice in an AU context; thus creating a tension-free relationship between the ICC and national legal systems in Africa. It suggests that the relationship should be conceived as one of complementarity and interdependence; with an assured acknowledgement of the cultural specificities of today’s Africa

Soil and Phyllosphere Microorganisms of the Rapeseed (Brassica napus L.) Holobiont Involved in Chloromethane Emissions

Brassica napus, or rapeseed, is one major oilseed crop in Europe and Germany and is used for food, feed, and Biodiesel production. Chloromethane (CH3Cl) is the most abundant halogenated organic compound in the atmosphere and triggers the chlorine-mediated destruction of the ozone layer. Anthropogenic sources became negligible because of taken measures according to the Montreal Protocol (1987) and therefore natural sources such as plants became more relevant for the global chloromethane budget. The actual global budget is imbalanced through missing sinks, which may be activities of soil and phyllosphere microbiomes which together with the plant is considered as the holobiont. The amount of CH3Cl from crops has not been addressed and might even increase under stresses such as elevated soil salinization and temperature. We proved that B. napus (rapeseed) plants emit CH3Cl. Certain methylotrophs (microorganisms that utilize one-carbon compounds) degrade CH3Cl and can gain a selective advantage while colonizing plants. Moreover, methylotrophs thrive in the rhizosphere of grassland plants. The rapeseed associated microbiome likely harbours methylotrophs that degrade CH3Cl. Therefore, we addressed in this study the rapeseed holobiont to resolve its response to stressors such as salt and temperature in regard to CH3Cl emission. We addressed in our project the following objectives: (i) To measure CH3Cl emission rates from single B. napus holobionts under different NaCl and temperature stress levels in pot experiments, (ii) to assess the B. napus microbiome and its CH3Cl degradation ability through amplicon sequencing of bacterial 16S rRNA genes and functional gene markers. The summer cultivar MAKRO was used as a model organism. We identified methylotrophs that responded to salt and temperature stress conditions in the phyllo- and rhizosphere of rapeseed and correlated those to the observed net emission rates