Evaluation of a new supply strategy based on stochastic programming for a fashion discounter

Fashion discounters face the problem of ordering the right amount of pieces in each size of a product. The product is ordered in pre-packs containing a certain size-mix of a product. For this so-called lot-type design problem, a stochastic mixed integer linear programm was developed, in which price cuts serve as recourse action for oversupply. Our goal is to answer the question, whether the resulting supply strategy leads to a supply that is significantly more consistent with the demand for sizes compared to the original manual planning. Since the total profit is influenced by too many factors unrelated to sizes (like the popularity of the product, the weather or a changing economic situation), we suggest a comparison method which excludes many outer effects by construction. We apply the method to a real-world field study: The improvements in the size distributions of the supply are significant.Comment: 5 pages, 1 tabl

Plastic pollution of rivers: citizen scientists investigate litter quantities, composition, and sources

The pollution of the environment with anthropogenic litter, especially plastics, has become a major global problem. Large quantities of litter pose a hazard to hundreds of species, infrastructure, and human health. While the ocean pollution of plastics has been the research focus of most studies to date, the majority of litter derives from land and rivers play a key role in the transport of litter from inland sources to the sea. As litter sources are very diverse, it is imperative to investigate a variety of environments to gain an overview of the extent of pollution and derive mitigation measures. Citizen science (involving the general public in research) is a promising approach to collect such data over large geographic areas. This thesis presents the results of the citizen science campaign Plastic Pirates, involving schoolchildren in the research of anthropogenic litter pollution of rivers. The project was conducted in Germany and Chile, involving (since 2016) over 15,000 schoolchildren and their teachers. The studies presented here analysed data from the campaigns of 2016 and 2017 of the Plastic Pirates. The results show that litter pollution of the riparian environment is ubiquitous in both countries: larger litter at the sampling sites occurred at almost all sampling sites (91% in Germany, 100% in Chile), including litter hazardous to humans (found at 89% of sampling sites in Germany, in Chile this analysis was not conducted). Litter quantities at the riverside averaged 0.5 items and 1.8 items per m2 in Germany and Chile, respectively. In both countries, plastics and cigarette butts were among the most frequently found litter items. The most important source of much of this litter are recreational visitors (i.e. people passing spare time at the riverside, consuming food). In addition, in Chile, residents and people illegally dumping litter have also been identified as important sources. Small plastic particles (meso- and microplastics, i.e. particles in the size range of 24.99 to 1 mm) have also frequently been found in the nets used to sample the river water (in 57% of samples in Germany, and 43% of samples in Chile). Considering that only particles larger than 1 mm were sampled, it can be assumed that the pollution by even smaller particles is common in the two countries. In Germany, some hotspots of pollution with small plastic particles were discovered, meaning sites where many particles were found (over 50 particles per hour). Potential sources of these particles were the plastic producing industry and wastewater treatment plants. The employed citizen science approach, involving schoolchildren and their teachers, proved valuable to collect many data in entire Germany and large sections of Chile. A wide variety of rivers were investigated, including smaller rivers, usually not in the focus of riparian litter studies. In addition to the scientific data collected by the schoolchildren, citizen science is a promising approach to raise the environmental awareness and scientific literacy of participants, and, in this process, plays an important role towards the opening of research processes to the general public

Structural perfection of Hg1−xCdxTe Grown by THM

The defect structure of single crystals of Hg1-xCdxTe grown by the travelling heater method (THM) has been investigated using X-ray double crystal topography and a chemical etching technique. The structural perfection is found to depend on the ratio of growth and solidus temperature Tg/Ts

The Ngəmba interrogative verb ghě ‘to what?’

While interrogative pronouns, adverbials, and determiners seem to constitute universal word categories (Ultan 1978), interrogative verbs are rather rare worldwide (Hagège 2008). One of the languages to attest this rare category is Ngəmba, a Ghomala’ variety of the Eastern Grassfields Bantu group in Cameroon. This article provides a first descriptive outline of the semantic and morphosyntactic properties of the Ngəmba interrogative verb ghě ‘do what?’. Based on comparative evidence from micro-variation across closely related neighbouring Ghomala’ varieties, it fleshes out a historical model that traces the Ngəmba interrogative verb back to a fusion of a prior verb meaning ‘do’ with an interrogative element

Regulation mechanisms of pheromone release in males of the desert locust, Schistocerca gregaria

Die Wüstenheuschrecke, Schistocerca gregaria, kommt in zwei Phasen vor, die sich morphologisch, physiologisch und ethologisch unterscheiden (UVAROV 1966, PENER & YERUSHALMI 1998). Während in der solitären Phase die Individuendichte sehr gering ist, bilden die Tiere in der gregären Phase riesige Schwärme mit mehreren Millionen Individuen. Unter den Bedingungen der stark erhöhten sexuellen Konkurrenz in der gregären Phase nutzen die Männchen zur chemischen Unterstützung der postkopulatorischen Partnerbewachung Phenylacetonitril (PAN, syn. Benzylcyanid) als Courtship Inhibiting Pheromone und zur Eigenmarkierung als Abstinon (SEIDELMANN & FERENZ 2002). PAN wird von Epidermis-Drüsenzellen hauptsächlich der Flügel und Sprungbeine produziert und nicht gespeichert (SEIDELMANN et al. 2003). Das Pheromon wird nur von geschlechtsreifen, gregären Männchen proportional zur Abundanz sexueller Konkurrenten abgegeben (DENG et al. 1996, SEIDELMANN et al. 2000). Als sensorische Eingänge zur Detektion einer Konkurrenz-Situation könnten neben optischen und olfaktorischen Kanälen auch die Chemorezeptoren der basiconischen Sensillen an den Sprungbein-Femoris dienen. Diese sind mit Mechanorezeptoren kombiniert (CHAPMAN 1982), welche den Wechsel von solitärem zu gregärem Verhalten induzieren (SIMPSON et al. 2001) und zur Wahrnehmung der Populationsdichte dienen. Die Bindung des Pheromons an die Geschlechtsreife (ca. 2 Wochen nach Adultschlupf) und die Anwesenheit von Paarungs-Konkurrenten deuten in Verbindung mit der fehlenden Speicherung des Pheromons auf eine Regulation der Biosynthese hin. In ersten Versuchen konnte gezeigt werden, dass die Synthese von PAN einer neurohormonalen Kontrolle durch ein PAN-Biosynthese-Aktivierendes-Neuropeptid (PAN-BAN) unterliegt (SEIDELMANN & FERENZ 2003). Die Struktur des Neuropeptids konnte bislang noch nicht aufgeklärt werden. Daher sollte durch die Verwendung von Rohextrakten folgenden Fragestellungen nachgegangen werden: (a) Welche sensorischen Eingänge induzieren eine PAN-BAN-Abgabe? (b) Wo wird PAN-BAN gebildet? (c) Wird die Kompetenz zur PAN-Abgabe durch die Reifung der Geschlechtsorgane oder durch den Titer des Reifungshormons der Insekten, Juvenilhormon (JH), gesteuert?Male desert locusts in the gregarious phase release phenylacetonitrile (PAN) when becoming sexually mature and turning yellow. The pheromone has repellent characteristics toward conspecifics. PAN is used by males in dense populations as a courtship inhibiting pheromone to chemically enhance mate guarding. Desert locust males produce PAN only when being grouped with other mature males. After physical isolation from sexual competitors PAN release drops to zero within a few days. Synthesis and release of PAN are under neurohormonal control by a PAN Biosynthesis Activating Neuropeptide (PAN-BAN). Here we report that PAN-BAN is produced in the oesophageal and suboesophageal ganglia and transported via the haemolymph to the epidermal pheromone gland cells. The release of PAN-BAN requires the perception of visual (complex eyes) or olfactory (antenna) stimuli from other mature males. Synchronism of sexual maturation and gland cell competence to produce PAN does not depend on a factor released by the testis or accessory glands. Instead Juvenile Hormone (JH) was found to be directly or indirectly involved in the regulation of PAN biosynthesis. Increasing the JH titre by transplanting corpora allata into juvenile gregarious males triggered the pheromone release within a couple of days. Whether JH stimulates directly the PAN-BAN receptor presence or the pheromone biosynthesis enzyme apparatus of the gland cells or indirectly by a still unknown factor remains to be investigated

Study of Hg vacancies in (Hg,Cd)Te after THM growth and post-growth annealing by positron annihilation

Positron lifetime measurements have been performed to study vacancy defects in Hg0.78Cd0.22Te. Post-growth annealing under various Hg vapour pressure conditions have been used to create a well-defined number of Hg vacancies. The sensitivity range of the positron annihilation method was found to be 1015 < cHgvac<1018 cm-3. The obtained experience has been used to investigate THM-grown single crystals. The measured longitudinal and radial dependence of the vacancy concentration can be explained by the temperature profile in the grown (Hg,Cd)Te ingots

Literal and metaphorical usages of Babanki EAT and DRINK verbs

In Babanki, a Grassfields Bantu language of North-West Cameroon, two of the numerous consumption verbs, namely the generic verbs ʒɨ́ ‘eat’ and ɲʉ́ ‘drink’, constitute a major source of metaphorical extensions outside the domain of ingestion. Setting out from a characterisation of the basic meanings of these two lexical items as they emerge from their paradigmatic relations within the semantic field of alimentation processes, this paper explores the figurative usages of the two verbs and their underlying semantic motivations. Semantic extensions that radiate from eat can be subsumed under two closely related structural metaphors, i.e. APPROPRIATION OF RESOURCES IS EATING and WINNING IS EATING. The first metaphor construes the acquisition and exploitation of non-food items such as material possession as eating, while the second metaphor casts the acquisition of immaterial advantage in the mould of eating. Both metaphors have further entailments, i.e. the derivation of pleasure from consumption of resources, the depletion of resources via consumption and the deprivation of a third party from access to these resources. Semantic extensions that radiate from drink can be accounted for in two structural metaphors, i.e. INHALATION IS DRINKING and ABSORPTION IS DRINKING. Remarkably, some metaphorical extensions of consumption verbs attested in other African languages, such as extensions of EAT for sexual intercourse and for killing, and the extensions of DRINK for undergoing trouble and enduring painful experiences are absent in Babanki