A branch & bound algorithm to determine optimal bivariate splits for oblique decision tree induction

Univariate decision tree induction methods for multiclass classification problems such as CART, C4.5 and ID3 continue to be very popular in the context of machine learning due to their major benefit of being easy to interpret. However, as these trees only consider a single attribute per node, they often get quite large which lowers their explanatory value. Oblique decision tree building algorithms, which divide the feature space by multidimensional hyperplanes, often produce much smaller trees but the individual splits are hard to interpret. Moreover, the effort of finding optimal oblique splits is very high such that heuristics have to be applied to determine local optimal solutions. In this work, we introduce an effective branch and bound procedure to determine global optimal bivariate oblique splits for concave impurity measures. Decision trees based on these bivariate oblique splits remain fairly interpretable due to the restriction to two attributes per split. The resulting trees are significantly smaller and more accurate than their univariate counterparts due to their ability of adapting better to the underlying data and capturing interactions of attribute pairs. Moreover, our evaluation shows that our algorithm even outperforms algorithms based on heuristically obtained multivariate oblique splits despite the fact that we are focusing on two attributes only

Improved resource efficiency and cascading utilisation of renewable materials

In light of various environmental problems and challenges concerning resource allocation, the utilisation of renewable resources is increasingly important for the efficient use of raw materials. Therefore, cascading utilisation (i.e., the multiple material utilisations of renewable resources prior to their conversion into energy) and approaches that aim to further increase resource efficiency (e.g., the utilisation of by-products) can be considered guiding principles. This paper therefore introduces the Special Volume “Improved Resource Efficiency and Cascading Utilisation of Renewable Materials”. Because both research aspects, resource efficiency and cascading utilisation, belong to several disciplines, the Special Volume adopts an interdisciplinary perspective and presents 16 articles, which can be divided into four subjects: Innovative Materials based on Renewable Resources and their Impact on Sustainability and Resource Efficiency, Quantitative Models for the Integrated Optimisation of Production and Distribution in Networks for Renewable Resources, Information Technology-based Collaboration in Value Generating Networks for Renewable Resources, and Consumer Behaviour towards Eco-friendly Products. The interdisciplinary perspective allows a comprehensive overview of current research on resource efficiency, which is supplemented with 15 book reviews showing the extent to which textbooks of selected disciplines already refer to resource efficiency. This introductory article highlights the relevance of the four subjects, presents summaries of all papers, and discusses future research directions. The overall contribution of the Special Volume is that it bridges the resource efficiency research of selected disciplines and that it presents several approaches for more environmentally sound production and consumption

Russisch-saudisches Kräftemessen am Ölmarkt: Motive, Strategien und Erfolgschancen beider Staaten

Mit Russlands Ablehnung weiterer Förderkürzungen und der darauffolgenden Ankün­digung Saudi-Arabiens, die eigene Ölproduktion hochzufahren, ist Anfang März ein massiver Preisverfall auf dem internationalen Ölmarkt eingetreten. Während Saudi-Arabien mit niedrigen Preisen seine Marktanteile ausbauen will, ist die Strategie Russlands keineswegs eindeutig. Moskau will zwar an seiner Förderquote festhalten, hat aber auch kein Interesse an einer ausgedehnten Preisschlacht. Ob Saudi-Arabien mit seiner Eskalation Erfolg hat oder sich Russlands kompromissloses Auftreten aus­zahlen wird, hängt nicht nur vom Durchhaltevermögen der beiden Länder ab. Ent­scheidend sind auch die Entwicklung der Ölnachfrage und die Anpassungsreaktionen anderer Ölförderer, insbesondere der US-amerikanischen Fracking-Industrie. (Autorenreferat

Reactions of dizincocene with sterically demanding bis(iminodi(phenyl) phosphorano) methanes

Reactions of Cp*(2)Zn(2) with sterically demanding bis(iminodi( phenyl) phosphorano) methanes LH (LH = CH(2)(Ph(2)P=NR)(2) (R = Ph L(1) H, SiMe(3) L(2) H, 2,6- i- Pr(2)C(6)H(3) (Dipp) L(3) H) at ambient temperature occurred with elimination of Cp*H and subsequent formation of the homoleptic complex L(2)(1)Zn(2) 1 and the heteroleptic complexes LZnZnCp* (L = L(2) 2, L(3) 3, L(1) 4). 3 is the first structurally characterized heteroleptic organozinc complex with the zinc atoms in the formal oxidation state + 1

Impact of Protein Intake during Weight Loss on Preservation of Fat-Free Mass, Resting Energy Expenditure, and Physical Function in Overweight Postmenopausal Women: A Randomized Controlled Trial

Introduction: Weight loss in old age increases the risk of sarcopenia caused by the age-related reduction of fat-free mass (FFM). Due to the strong correlation between FFM and resting energy expenditure (REE), the maintenance of this must also be considered. Besides, the physical function (PF) must be maintained. Objective: The impact of protein intake on changes in FFM, REE, and PF during weight loss in overweight postmenopausal women was investigated. Methods: Fifty-four postmenopausal women (BMI 30.9 ± 3.4; age 59 ± 7 years) were randomized into 2 groups receiving energy-restricted diets with either 0.8 g (normal protein; NP) or 1.5 g protein/kg body weight (high protein; HP) for 12 weeks, followed by a 6-month follow-up phase with an ad libitum food intake. FFM, REE, and PF (strength, endurance, and balance) were measured at baseline, after weight loss, and after follow-up. Results: Forty-six women completed the weight loss intervention and 29 were followed up. The weight loss was –4.6 ± 3.6 kg (HP) and –5.2 ± 3.4 kg (NP; both p < 0.001) and the weight regain during follow-up was 1.3 ± 2.8 kg (HP; p = 0.03) and 0.4 ± 2.5 kg (NP; p = 0.39), with no differences between groups. Similar decreases in FFM (–0.9 ± 1.1 [HP] vs. –1.0 ± 1.3 kg [NP]) and REE (–862 ± 569 [HP] vs. –1,000 ± 561 kJ [NP]; both p < 0.001) were observed in both groups. During follow-up, no changes in FFM were detected in either group, whereas in the NP group the REE increased again (+138 ± 296; p = 0.02). The main determinants of FFM loss were the energy deficit and the speed of weight loss. In the NP group, the Short Physical Performance Battery score improved with weight loss (+0.6 ± 0.8; p < 0.001) and handgrip strength decreased (–1.7 ± 3.4 kg; p < 0.001), whereas no changes were observed in the HP group. Conclusions: An HP weight-loss diet without exercise had no impact on preservation of FFM and REE but may help to maintain muscle strength in postmenopausal women

Boron Contents of German Mineral and Medicinal Waters and Their Bioavailability in Drosophila melanogaster and Humans

Scope Boron is a trace element that naturally occurs in soil, making mineral and medicinal water important contributors to overall intake. Thus, in a systematic screening, the mean boron concentrations of 381 German mineral and medicinal waters are determined. Methods and results Boron concentrations in mineral and medicinal waters are analyzed by inductively coupled mass spectrometry (ICP-MS). Highest boron values find in waters from the southwest of Germany. The boron content of the waters is positively correlated with the concentration of most other analyzed bulk elements, including calcium, potassium, magnesium, and sodium. Mineral waters with either low (7.9 µg L-1 ), medium (113.9 µg L-1 ), or high (2193.3 µg L-1 ) boron content are chosen for boron exposure experiments in fruit flies (Drosophila melanogaster) and humans. In flies, boron-rich mineral water significantly increases boron accumulation, with the accumulation predominantly occurring in the exoskeleton. In humans, serum boron and 24-h urinary boron excretion significantly increase only in response to the intake of boron-rich mineral water. Conclusion Overall, the current data demonstrate that mineral and medicinal waters vary substantially in the content of boron and that boron-rich mineral water can be used to elevate the boron status, both in flies and humans

Overview of the results of the organics PET Study of the cometary samples returned from comet Wild 2 by the Stardust mission

This presenation will provide an overview of the efforts and results produced by the Organics Preliminary Examination Team during their studies of the samples returned from comet Wild 2 by the Stardust spacecraft