Routing with Reloads

We examine routing problems with reloads, how they can be modeled, their properties and how they can be solved. We propose a simple model, the Pickup and Delivery Problem with Reloads (RPDP), that captures the process of reloading and can be extended for real world applications. We present results that show that the RPDP is solvable in polynomial time if the number of requests is bounded by a constant. Additionally, we examine a special case of the RPDP, the k-Star Hub Problem. This problem is solvable efficiently by network flow approaches if no more than two hubs are available. Otherwise, it is NP-complete. In the second part of this thesis, additional constraints are incorporated into the model and a tabu search heuristic for this problem is presented. The heuristic has been implemented and tested on several benchmarking instances, both artificial and a real-world application. In the appendix, we discuss the application of column generation for a reload problem

Removal of mismatched bases from synthetic genes by enzymatic mismatch cleavage

The success of long polynucleotide de novo synthesis is largely dependent on the quality and purity of the oligonucleotides used. Generally, the primary product of any synthesis reaction is directly cloned, and clones with correct products have to be identified. In this study, a novel strategy has been established for removing undesired sequence variants from primary gene synthesis products. Single base-pair mismatches, insertions and deletions were cleaved with specific endonucleases. Three different enzymes—T7 endonuclease I, T4 endonuclease VII and Escherichia coli endonuclease V—have been tested. As a model, a synthetic polynucleotide encoding the bacterial chloramphenicol-acetyltransferase (cat) was synthesized using different methods for one step polynucleotide synthesis based on ligation of oligonucleotides. The influence of enzymatic mismatch cleavage (EMC) as an error correction step on the frequency of correct products was analyzed by functional cloning of the synthetic cat and comparing the error rate with that of untreated products. Significant reduction of all mutation types was observed. Statistical analysis revealed that the T4 and E.coli endonucleases reduced the occurrence of mutations in cloned synthetic gene products. The EMC treatment was successful especially in the removal of deletions and insertions from the primary ligation products

Complexity Results on a Paint Shop Problem

Motivated by an application in the automobile industry, we present results and conjectures on a new combinatorial problem: Given a word w and restricted reservoirs of colored letters, synthesize w with a minimal number of color changes. We present a dynamic program that solves this problem and runs in polynomial time if we bound both, the number of different letters and colors. Otherwise, the problem is shown to be NP-complete. Additionally, we focus on upper bounds on the minimal number of color changes, simultaneously giving results for special instances, and posing open questions

Webster’s Delay Formula – revisited

The equations developed byWebster in his famous 1958 report[10] are still the basis of traffic signal planning today. They are being used in handbooks like the HCM and similar instruments world-wide. However, the handbook approach typically works with approximations to the original equations which have stood the test of time, but may nevertheless not be the best to be done today. This work analyzes Webster’s approach and advocates a more modern use of it which utilizes the tremendous advances in computer hardware and software. This is being done by comparing approximations to exact solutions, and by a comparison between various models and Webster’s equations itself. It is shown that there can be significant differences in the calculation of optimal cycle times and consequent delay times

PMMA vertebroplasty in patients with malignant vertebral destruction of the thoracic and lumbar spine

Object: Patients with osteolytic metastases frequently suffer from serious local and radicular pain. Pathophysiologically, local pain arises from skeletal instability, whereas radicular pain originates from compression of nerve roots by local tumor growth. Causal treatment of osteolytic metastases in disseminated malignant disease is very difficult. Resection of vertebrae, in combination with ventro-dorsal stabilization, is a complex treatment for patients with a limited life expectancy. Percutaneous polymethylmethacrylate (PMMA) vertebroplasty is a new and easy method of relieving patients' pain. In addition, it is both cost effective and safe. Pain is reduced immediately after treatment. Due to the regained vertebral stability, early mobilization of the patients is possible

Stichprobe der Integrierten Erwerbsbiografien : IEBS 1.0, Handbuch-Version 1.0.0 (Integrated Employment Biographies Sample IEBS 1.0)

Bei dem Datensatz handelt es sich um eine Zufallsstichprobe aus den Integrierten Erwerbsbiografien (IEB) des IAB, der für die Fachöffentlichkeit zugänglich ist. Er enthält Angaben zu folgenden Merkmalsgruppen: soziodemografische Merkmale, Beschäftigung, Leistungsbezug, Maßnahmen der aktiven Arbeitsmarktförderung und Arbeitssuche. Die Ziehung der Stichprobe erfolgt über die zufällige Auswahl von acht Geburtstagen, wobei alle Personen mit diesen Geburtstagen gezogen werden, was etwa 2,2 Prozent der Personen der IEB entspricht. Die Variablenbeschreibung des Datensatzes gliedert sich in einen allgemeinen Teil mit einer Merkmalsübersicht und einer Beschreibung der Typisierung der in den Daten vorkommenden fehlenden Werte. Es folgen Beschreibungen der einzelnen Merkmale der Variablen Identifikationsnummer, Spellanfang und -ende, generierte technisch Merkmale, Personenstatus vor, während und nach dem aktuellen Spell, persönliche Merkmale, Angaben zu Beschäftigungsverhältnis und Arbeitssuche sowie Ortsangaben. Die vier Datenquellen der IEB werden vorgestellt, die über die Sozialversicherungsnummern und BA-Kundennummern verknüpft werden: 1. die Beschäftigten-Historik des IAB; 2. die Leistungsempfänger-Historik des IAB; 3. die Maßnahme-Teilnehmer-Gesamtdatenbank und 4. den Arbeitsuchendenstatus aus dem Bewerberangebot. Zudem wird auf Datenqualität, Episodensplitting, Anyoymisierung und Datenauswertung eingegangen. (IAB)Integrierte Erwerbsbiografien, Stichprobe, Datengewinnung, Datenaufbereitung, IAB-Beschäftigtenhistorik, IAB-Leistungsempfängerhistorik, IAB-Maßnahmeteilnehmergrunddatei, IAB-Bewerberangebotsdatei, Datenqualität, Datensicherheit, Datenzugang

Verlustzeitenbasierte LSA-Steuerung eines Einzelknotens

Neue Methoden zur Verkehrsdatenerfassung wie die Fahrzeug-Infrastruktur-Kommunikation, der Floating Car-Ansatz und die Videodetektion eröffnen die Möglichkeit, neue Verfahren zur verkehrsabhängigen Lichtsignalanlagensteuerung zu realisieren. In dem Beitrag wird ein Verfahren beschrieben, das aus diesen Quellen Daten in Form von Fahrzeugverlustzeiten direkt zur Steuerung eines Einzelknotens verwendet. Die robuste Ausgestaltung des Verfahrens sorgt dabei dafür, dass auch mit einer lückenhaften Datenlage, wie z. B. aufgrund geringer Ausstattungsraten kommunikationsfähiger Fahrzeuge, angemessen umgegangen werden kann. Mit Hilfe einer mikroskopischen Simulationsstudie wird nachgewiesen, dass das neue Verfahren bei der Qualität des Verkehrsablaufs das gleiche Niveau wie eine traditionelle Zeitlückensteuerung erreicht oder dieses unter bestimmten Bedingungen sogar übersteigt. Mit abnehmender Ausstattungsrate ergibt sich dabei allerdings ein Qualitätsverlust, der ebenfalls mit Hilfe der mikroskopischen Simulation quantifiziert wird und wichtige Erkenntnisse für einen möglichen Praxistest liefert.State-of-the-art traffic data sources like Car-to-Infrastructure communication, Floating Car Data and video detection offer great new prospects for vehicle-actuated traffic signal control. Due to this, the article deals with a recent approach which uses vehicles’ delay times for real-time control of traffic signals at an isolated intersection. One of the strengths of the new approach is that it can handle also incomplete data sets, e.g. caused by low penetration rates of vehicles equipped with Car-to-Infrastructure communication technology, in an appropriate manner. Based on a microscopic simulation study the high quality of this innovative approach is demonstrated, which is equal or even outperforms the well-known headway-based control. However, a decreasing penetration rate of equipped vehicles means a reduced quality of signals’ control, which is quantified in the microscopic simulation study, too, and provides useful information for tests in the field

Histone deacetylase inhibition sensitizes osteosarcoma to heavy ion radiotherapy

Background: Minimal improvements in treatment or survival of patients with osteosarcoma have been achieved during the last three decades. Especially in the case of incomplete tumor resection, prognosis remains poor. Heavy ion radiotherapy (HIT) and modern anticancer drugs like histone deacetylase inhibitors (HDACi) have shown promising effects in osteosarcoma in vitro. In this study, we tested the effect of HIT and the combination of HIT and the HDACi suberoylanilide hydroxamic acid (SAHA) in a xenograft mouse model. Methods: Osteosarcoma xenografts were established by subcutaneous injection of KHOS-24OS cells and treated with either vehicle (DMSO), SAHA, HIT or HIT and SAHA. Tumor growth was determined and tumor necrosis, proliferation rate, apoptotic rate as well as vessel density were evaluated. Results: Here, we show that the combination of HIT and SAHA induced a significant delay of tumor growth through increased rate of apoptosis, increased expression of p53 and p21Waf1/Cip1, inhibition of proliferation and angiogenesis compared to tumors treated with HIT only. Conclusion: HIT and in particular the combination of HIT and histone deacetylase inhibition is a promising treatment strategy in OS and may be tested in clinical trials

Combination of suberoylanilide hydroxamic acid with heavy ion therapy shows promising effects in infantile sarcoma cell lines

<p>Abstract</p> <p>Introduction</p> <p>The pan-HDAC inhibitor (HDACI) suberoylanilide hydroxamic acid (SAHA) has previously shown to be a radio-sensitizer to conventional photon radiotherapy (XRT) in pediatric sarcoma cell lines. Here, we investigate its effect on the response of two sarcoma cell lines and a normal tissue cell line to heavy ion irradiation (HIT).</p> <p>Materials and methods</p> <p>Clonogenic assays after different doses of heavy ions were performed. DNA damage and repair were evaluated by measuring γH2AX via flow-cytometry. Apoptosis and cell cycle analysis were also measured via flow cytometry. Protein expression of repair proteins, p53 and p21 were measured using immunoblot analysis. Changes of nuclear architecture after treatment with SAHA and HIT were observed in one of the sarcoma cell lines via light microscopy after staining towards chromatin and γH2AX.</p> <p>Results</p> <p>Corresponding with previously reported photon data, SAHA lead to an increase of sensitivity to heavy ions along with an increase of DSB and apoptosis in the two sarcoma cell lines. In contrast, in the osteoblast cell line (hFOB 1.19), the combination of SAHA and HIT showed a significant radio-protective effect. Laser scanning microscopy revealed no significant morphologic changes after HIT compared to the combined treatment with SAHA. Immunoblot analysis revealed no significant up or down regulation of p53. However, p21 was significantly increased by SAHA and combination treatment as compared to HIT only in the two sarcoma cell lines - again in contrast to the osteoblast cell line. Changes in the repair kinetics of DSB p53-independent apoptosis with p21 involvement may be part of the underlying mechanisms for radio-sensitization by SAHA.</p> <p>Conclusion</p> <p>Our <it>in vitro </it>data suggest an increase of the therapeutic ratio by the combination of SAHA with HIT in infantile sarcoma cell lines.</p