A flexible metaheuristic framework for solving rich vehicle routing problems

Route planning is one of the most studied research topics in the operations research area. While the standard vehicle routing problem (VRP) is the classical problem formulation, additional requirements arising from practical scenarios such as time windows or vehicle compartments are covered in a wide range of so-called rich VRPs. Many solution algorithms for various VRP variants have been developed over time as well, especially within the class of so-called metaheuristics. In practice, routing software must be tailored to the business rules and planning problems of a specific company to provide valuable decision support. This also concerns the embedded solution methods of such decision support systems. Yet, publications dealing with flexibility and customization of VRP heuristics are rare. To fill this gap this thesis describes the design of a flexible framework to facilitate and accelerate the development of custom metaheuristics for the solution of a broad range of rich VRPs. The first part of the thesis provides background information to the reader on the field of vehicle routing problems and on metaheuristic solution methods - the most common and widely-used solution methods to solve VRPs. Specifically, emphasis is put on methods based on local search (for intensification of the search) and large neighborhood search (for diversification of the search), which are combined to hybrid methods and which are the foundation of the proposed framework. Then, the main part elaborates on the concepts and the design of the metaheuristic VRP framework. The framework fulfills requirements of flexibility, simplicity, accuracy, and speed, enforcing the structuring and standardization of the development process and enabling the reuse of code. Essentially, it provides a library of well-known and accepted heuristics for the standard VRP together with a set of mechanisms to adapt these heuristics to specific VRPs. Heuristics and adaptation mechanisms such as templates for user-definable checking functions are explained on a pseudocode level first, and the most relevant classes of a reference implementation using the Microsoft .NET framework are presented afterwards. Finally, the third part of the thesis demonstrates the use of the framework for developing problem-specific solution methods by exemplifying specific customizations for five rich VRPs with diverse characteristics, namely the VRP with time windows, the VRP with compartments, the split delivery VRP, the periodic VRP, and the truck and trailer routing problem. These adaptations refer to data structures and neighborhood search methods and can serve as a source of inspiration to the reader when designing algorithms for new, so far unstudied VRPs. Computational results are presented to show the effectiveness and efficiency of the proposed framework and methods, which are competitive with current state-of-the-art solvers of the literature. Special attention is given to the overall robustness of heuristics, which is an important aspect for practical application

Prospect Theory and Inflation Perceptions - An Empirical Assessment

Building on the hypotheses of loss aversion with respect to price increases and availability of frequently bought goods, Brachinger (2006,2008) constructs an alternative index of perceived inflation (IPI), which can reproduce the jump in the measure for perceived inflation after the Euro introduction in Germany that was not observable in standard HICP inflation. We test the hypotheses of Prospect Theory with regard to households’ inflation perceptions underlying Brachinger’s IPI in a panel estimation for 12 European countries. There is evidence that perceptions react more strongly to ‘losses’ in inflation than to ‘gains’ before the Euro cash changeover, but not afterwards. Moreover, we find empirical support for the availability hypothesis, stating that frequently bought goods have a stronger influence on inflation perceptions than the overall price index.Inflation Perceptions, Prospect Theory, Dynamic Panel

Confirmation of a low HER2 positivity rate of breast carcinomas - limitations of immunohistochemistry and in situ hybridization

<p>Abstract</p> <p>Background</p> <p>Accurate assessment of the human epidermal growth factor receptor 2 (HER2) of invasive breast cancer is essential to treatment decisions since the advent of targeted therapy with the humanized monoclonal antibody trastuzumab and the dual tyrosine kinase inhibitor lapatinib. In the literature, the percentage of HER2-overexpressed/amplified breast carcinomas range from 3% to 30%. The routinely assigned low rate of 9% of HER2-overexpressed breast carcinomas alarmed one of our gynecologists who requested to confirm our HER2 test results.</p> <p>Methods</p> <p>A small study of 83 patients with breast carcinoma was designed to reexamine the routinely assessed HER2 status using immunohistochemistry and fluorescence in situ hybridization.</p> <p>Results</p> <p>The low rate of 9% of HER2-overexpressed/amplified breast tumors (DIN1C-3, invasive carcinoma) could be confirmed. However, FISH revealed two false positive cases and one false negative case. Moreover a case with an equivocal result in FISH was detected.</p> <p>Conclusion</p> <p>The HER2 positivity rate may be as low as 9%. The novel ASCO/CAP criteria for assessing immunohistochemical results in HER 2 testing reduce the false positive rate of HER2. First-line testing with immunohistochemistry may obscure false positive and false negative test results. In heterogeneous carcinomas even fluorescence in situ hybridization may not succeed in a correct evaluation of HER2.</p

Facial expressions and personality: A kinematical investigation during an emotion induction experiment

Background/Aims: In order to elucidate the relationship between personality traits and expression of positive emotions in healthy volunteers, standardized personality inventories and kinematical analysis of facial expressions can be helpful and were applied in the present study. Methods: Markers fixed at distinct points of the face emitting ultrasonic signals at high frequency gave a direct measure of facial movements with high spatial-temporal resolution. Forty-six healthy participants (mean age: 40.7 years; 20 males, 26 females) watching a witty movie ('Mr. Bean') were investigated. Results: Speed of `laughing' was associated with higher scores on Zuckerman's Sensation Seeking Scale and NEO-FFI (Openness to Experience). Conclusion: Kinematical analysis of facial expressions seems to reflect sensation seeking and related personality styles. Higher speed of facial movements in sensation seekers suggests lowered serotonergic function. Copyright (c) 2006 S. Karger AG, Basel

Lessons Learned from an Outbreak in Germany, 2012-2013

Background We undertook investigations in response to an invasive meningococcal disease (IMD) outbreak in men who have sex with men (MSM) in Berlin 2012–2013 to better understand meningococcal transmission and IMD risk in MSM. Methods We retrospectively searched for further IMD cases in MSM in Germany through local health departments and undertook exploratory interviews. We performed antigen sequence typing, characterized fHbp and aniA genes of strains with the outbreak finetype and reviewed epidemiologically or spatiotemporally linked cases from 2002–2014. Results Among the 148 IMD-cases notified from 01.01.2012–30.09.2013 in 18–59 year-old men we identified 13 MSM in 6 federal states: 11 serogroup C (MenC, all finetype C:P1.5–1,10–8:F3-6), 2 MenB. Interviews with 7 MSM revealed frequent meeting of multiple partners online or via mobile apps and illicit drug use as potential risk factors. MenC incidence was 13-fold higher in MSM than non-MSM. MenC isolates from 9/11 MSM had a novel fHbp allele 766. All C:P1.5–1,10–8:F3-6 strains from MSM versus 16/23 from non-MSM had intact aniA genes (p = 0.04). Although definitive evidence for transmission among MSM in epidemiological or spatiotemporal clusters in 2002–2014 was lacking, clusters were more frequent in men aged 20–49 years. Molecular analysis of C:P1.5–1,10–8:F3-6 strains revealed cases with intact aniA since 2007, mainly associated with fHbp361, fHbp766 and fHbp813, all involving one or more MSM. Conclusions MenC incidence was elevated in MSM during the study period. Multiple casual sexual contacts and illicit drug use were common in affected MSM. In all strains from MSM we detected an intact aniA gene coding for a nitrite reductase, which permits survival in microanaerobic environments and could play a role in meningococcal transmission in MSM through urogenital colonization. Furthermore, meningococcal transmission among MSM may be sustained over large areas and thus require modified spatiotemporal scanning algorithms for timely detection and control

Sabatino de Ursis' Preface to the Taixi shuifa 泰西水法 (Hydromethods of the Great West; 1612): The 'Basic Discourse on Hydromethods' (Shuifa benlun 水法本論)

EnThis is the first complete translation into a Western language of Sabatino de Ursis' preface to the Taixi shuifa1. After a short summary of its contents and some remarks about the origin of this translation, the annotated text, accompanied by the Chinese transcription of the original, will be presented.ItQuesta è la prima traduzione completa in una lingua occidentale della prefazione di Sabatino de Ursis al Taixi shuifa1. Dopo un breve riassunto del suo contenuto e alcune osservazioni sull'origine di questa traduzione, viene presentato il testo annotato, accompagnato dalla trascrizione cinese dell'originale

Predominance of Methicillin Resistant Staphylococcus Aureus -ST88 and New ST1797 causing Wound Infection and Abscesses.

Although there has been a worldwide emergence and spread of methicillin-resistant Staphylococcus aureus (MRSA), little is known about the molecular epidemiology of MRSA in Tanzania. In this study, we characterized MRSA strains isolated from clinical specimens at the Bugando Medical Centre, Tanzania, between January and December 2008. Of 160 S. aureus isolates from 600 clinical specimens, 24 (15%) were found to be MRSA. Besides molecular screening for the Panton Valentine leukocidin (PVL) genes by PCR, MRSA strains were further characterized by Multi-Locus Sequence Typing (MLST) and spa typing. Despite considerable genetic diversity, the spa types t690 (29.1%) and t7231 (41.6%), as well as the sequence types (ST) 88 (54.2%) and 1797 (29.1%), were dominant among clinical isolates. The PVL genes were detected in 4 isolates; of these, 3 were found in ST 88 and one in ST1820. Resistance to erythromycin, clindamicin, gentamicin, tetracycline and co-trimoxazole was found in 45.8%, 62.5%, 41.6%, 45.8% and 50% of the strains, respectively. We present the first thorough typing of MRSA at a Tanzanian hospital.  Despite considerable genetic diversity, ST88 was dominant among clinical isolates at the Bugando Medical Centre. Active and standardized surveillance of nosocomial MRSA infection should be conducted in the future to analyse the infection and transmission rates and implement effective control measures