Implications, conflicts, and reductions for Steiner trees

The Steiner tree problem in graphs (SPG) is one of the most studied problems in combinatorial optimization. In the past 10 years, there have been significant advances concerning approximation and complexity of the SPG. However, the state of the art in (practical) exact solution of the SPG has remained largely unchallenged for almost 20 years. While the DIMACS Challenge 2014 and the PACE Challenge 2018 brought renewed interest into Steiner tree problems, even the best new SPG solvers cannot match the state of the art on the vast majority of benchmark instances. The following article seeks to advance exact SPG solution once again. The article is based on a combination of three concepts: Implications, conflicts, and reductions. As a result, various new SPG techniques are conceived. Notably, several of the resulting techniques are (provably) stronger than well-known methods from the literature that are used in exact SPG algorithms. Finally, by integrating the new methods into a branch-and-cut framework, we obtain an exact SPG solver that is not only competitive with, but even outperforms the current state of the art on an extensive collection of benchmark sets. Furthermore, we can solve several instances for the first time to optimality.

Středověká kožedělná produkce z Litovle

Between 1997 and 2017, an extensive collection of approximately 3,500 leather fragments from the second half of the 13th to the 15th century was obtained from archaeological rescue excavations carried out in the historic core of Litovel. Most of the finds come from public areas of the town. Only a few dozen artefacts have been determined in terms of their original function. All the remaining finds can be classified as primary to secondary waste, among which manufacturing waste was often present, indicating the nearby presence of a craft workshop. In the case of Litovel, this has been demonstrated at two sites, and hypothetically at three others. These are specifically shoemaker or cobbler workshops. The leather artefact assemblage from Litovel contains typical representatives of material culture from the High and Late Middle Ages, most often in the form of shoes (high and low cuts, children’s sizes), clothing accessories (belts), equipment (scabbards) and items rarely found elsewhere including unique objects such as a case for wax writing tablets and a face mask.

In This Issue

This issue is the fourth and final issue of the Journal for 2021. It reflects a widespread interest in the Asia Pacific with 30 articles from 11 countries. These countries include Australia, India, Iran, Indonesia, the Philippines, Saudi Arabia, Bangladesh. Vietnam, Thailand, Turkey and Hong Kong, China. This represents a significant collaboration of healthcare managers, leaders, academics, students, and health professionals from diverse health systems. This is a credit to them all and our reviewers. The topics addressed within the issue continue to be dominated by Covid_19 but are also more extensive than that topic. The topics include leadership, engagement, health literacy, employee performance, job satisfaction, mentoring, , artificial intelligence, big data to name many but not all. This is extensive collection of health management topics that should be of interest. Another continuing feature of this issue is the interest in publishing articles from international conferences. There are articles from four recent conferences. These included the 2021 Shape Symposium conducted from Australia and online, “Shaping the future for health management education and research in a time of flux and uncertainty”, held online in July and available at http://shape.org.au/. The Hong Kong Polytechnic University’s College of Professional and Continuing Education (CPCE) Conference “Post-pandemic health and long-term care: A new paradigm”. September 2021 with online and ‘in presence’ attendance. Two conferences highlighted in this issue are recognised from India with some eight articles published from these conferences. The conferences were the AICTE sponsored International Conference on Circular Economy, Management and Industry Leading towards Sustainability, October 2021 and the 2nd Conference on Business Data Analytics, November 2021 We wish to specifically mention these conferences and recognise the conference organisers and our guest co -editors on this occasion, who assisted us with the 8 selected articles. The guest co-editors are Mr. Anuj Kumar, Assistant Professor, Apeejay School of Management, Dwarka, Delhi, India https://www.apeejay.edu/asm/?utm_source=google&utm_medium=google+business+listing&utm_campaign=organic. (Top PGDM Colleges Delhi NCR) and Dr. Nimit Gupta, Professor, School of Management, The NorthCap University, Gurugram, India https://www.ncuindia.edu/educate-india- society/.

SSR-Sequencing Reveals the Inter- and Intraspecific Genetic Variation and Phylogenetic Relationships among an Extensive Collection of Radish (Raphanus) Germplasm Resources

Raphanus has undergone a lengthy evolutionary process and has rich diversity. However, the inter- and intraspecific phylogenetic relationships and genetic diversity of this genus are not well understood. Through SSR-sequencing and multi-analysis of 939 wild, semi-wild and cultivated accessions, we discovered that the European wild radish (EWR) population is separated from cultivated radishes and has a higher genetic diversity. Frequent intraspecific genetic exchanges occurred in the whole cultivated radish (WCR) population; there was considerable genetic differentiation within the European cultivated radish (ECR) population, which could drive radish diversity formation. Among the ECR subpopulations, European primitive cultivated radishes (EPCRs) with higher genetic diversity are most closely related to the EWR population and exhibit a gene flow with rat-tail radishes (RTRs) and black radishes (BRs)/oil radishes (ORs). Among Asian cultivated radishes (ACRs), Chinese big radishes (CBRs) with a relatively high diversity are furthest from the EWR population, and most Japanese/Korean big radishes (JKBRs) are close to CBR accessions, except for a few old Japanese landraces that are closer to the EPCR. The CBR and JKBR accessions are independent of RTR accessions; however, phylogenetic analysis indicates that the RTR is sister to the clade of CBR (including JWR), which suggests that the RTR may share the most recent common ancestry with CBRs and JWRs. In addition, Japanese wild radishes (JWRs), (namely, R. sativus forma raphanistroides) are mainly scattered between CBRs and EPCRs in PCoA analysis. Moreover, JWRs have a strong gene exchange with the JKBR, OR and RTR subpopulations. American wild radishes (AWRs) are closely related to European wild and cultivated radishes, and have a gene flow with European small radishes (ESRs), suggesting that the AWR developed from natural hybridization between the EWR and the ESR. Overall, this demonstrates that Europe was the origin center of the radish, and that Europe, South Asia and East Asia appear to have been three independent domestication centers. The EPCR, AWR and JWR, as semi-wild populations, might have played indispensable transitional roles in radish evolution. Our study provides new perspectives into the origin, evolution and genetic diversity of Raphanus and facilitates the conservation and exploitation of radish germplasm resources.

Ultrasound for the Generalist

Point of care ultrasound is a critical tool required for assessing all patients, providing rapid answers to clinical questions and facilitating high quality care for patients. This essential guide caters for all generalist clinicians beginning their ultrasound journey and extends to more advanced assessments for those with established ultrasound experience wishing to advance their knowledge and skills. It covers a wide range of ultrasound topics from echocardiography, thoracic and COVID-19 to emerging areas such as palliative care, hospital at home and remote and austere medicine. An extensive collection of colour images, videos and examples of clinical applications will inspire readers to acquire the skills of point of care ultrasound quickly, safely and systematically. The printed code on the inside of the cover provides access to an online version on Cambridge Core. An essential aid for acute clinicians, paramedics, general practitioners as well as remote medical providers, medical educators and students.

Author, text and cultural meaning: Vijay Mishra's Salman Rushdie and the genesis of secrecy

Vijay Mishra's meticulous analysis of the Rushdie Emory Archive - Salman Rushdie and the Genesis of Secrecy - is one of the most significant paperbacks to have been released in humanities publishing in 2021 (originally published in hardback in 2019). In one sense this book might be understood as a literary project, one that enriches understanding of the Rushdie's published works through the perspectives gained from close reading and detailed cross-referencing of Emory's extensive collection of the author's personal papers, unpublished manuscripts, digital materials and ephemera. However, to categorise The Genesis of Secrecy simply in terms of its literary credentials would be to overlook its conceptual and methodological value to wider areas of culture and media research. With this broader frame in mind, this review essay considers the book from an interdisciplinary perspective.

Aspects of a Bandkeramik settlement near Olteni in Transylvania

In Transylvania, settlements of the Transdanubian Linienbandkeramik (LBK) are predominantly found in the Braşov Depression. Excavations at the LBK settlement of Olteni, located on the right bank of the Olt River, brought to light the fragmented remains of at least two ground plans of Early Neolithic longhouses. These are the first convincing evidence of such structures in Romania. The pottery allows dating the site to a later Notenkopf phase of the LBK. Among the ceramic pieces, a fragment of a small altar and several multiply perforated objects are particularly conspicuous; this is the first time sieves have been discovered in an LBK context in Romania. In addition, the Olteni site yielded the most extensive collection of anthropomorphic and zoomorphic plastic in the entire Eastern Bandkeramik milieu.

Ivan Skušek Jr. and His Collection of Chinese Coins

Ivan Skušek Jr. (1877–1947), whose collection of Chinese and Japanese objects has been the subject of research and interest in recent years, can be considered the first collector of East Asian objects in the Slovene ethnic space to have built his collection systematically, examining and verifying the provenance, value, and significance of each item. His extensive collection can compare to Western European collections of East Asian objects while at the same time bearing a stamp of local uniqueness pertaining to the European periphery. Skušek’s legacy includes an important collection of Chinese money from all periods of Chinese history, which is introduced in this paper for the first time. A crucial distinction between this and other collections of Chinese coins is that evidence exists that tells us how Skušek collected the coins, and reveals a lot about his sources and advisors. It has long been known that during his stay in Beijing Skušek befriended many influential and knowledgeable people, including a Franciscan missionary, Fr. Maurus Kluge, who assisted him in assembling his numismatic collection. The paper presents the cooperation between the two in the light of a recent find––the original list and summary appraisal of the most valuable part of Skušek’s numismatic collection and Kluge’s letters to Skušek.

What Is a Safe Area? Definition, Typology and Empirical Cases

In today’s conflicts, the number of people needing physical protection is at an all-time high. Often, protection is provided by the creation of safe areas. Although the notion largely disappeared after the Srebrenica genocide, safe areas have continued to exist empirically. Recently, safe areas had a minor revival in academic analysis and in the political rhetoric vis-à-vis Syria. Yet, fundamental gaps remain as it is still unclear what a safe area actually is and whether all safe areas function in the same way. This article develops a precise definition and comprehensive typology of safe areas. The definition is based on considerations regarding geographical limitation and location, target group, kind of provided protection, involved actors, and effective existence. Furthermore, four ideal types of safe areas are identified based on a division between belligerents’ consent/international presence and different geographical sizes. This is complemented by an extensive collection of empirical cases since 1900.