Spin-harmonic structures and nilmanifolds

We introduce spin-harmonic structures, a class of geometric structures on Riemannian manifolds of low dimension which are defined by a harmonic unitary spinor. Such structures are related to SU(2) (dim=4,5), SU(3) (dim=6) and G_2 (dim=7) structures; in dimension 8, a spin-harmonic structure is equivalent to a balanced Spin(7) structure. As an application, we obtain examples of compact 8-manifolds endowed with non-integrable Spin(7) structures of balanced type.Comment: 34 pages, no figure

CBRN Threats and the Economic Analysis of Terrorism

The aim of this paper is to investigate the economic aspects of CBRN threats. For this purpose, the extent to which this topic is reflected in freely-accessible academic literature and the costs associated with such threats will be assessed. Furthermore, it is to be determined which industries have a particular interest in security against such CBRN threats.

Fuzzy logic as support for security and safety solution in soft targets

Security and safety situations in objects, which are categorized as soft targets, is difficult. The current solving is based on several different type of solving. Soft targets are specific objects, and it requires special software solution. The proposal is based on fuzzy logic. Fuzzy logic could apply more expert's knowledges and it could help owners and managers with adequate responses in critical situation, and also definition of adequate preventive actions. System solving could help effectivity of proposed measures. The decision making is based on this fuzzy logic support and aim is explained in paper.European Regional Development Fund under the project CEBIA-Tech Instrumentation [CZ.1.05/2.1.00/19.0376]; Internal Grant Agency of Tomas Bata University [IGA/FAI (CEBIA)/2016/12]; Ministry of the Interior of the Czech Republic [VI20152019049

Identifying algal symbionts in lichen symbioses

Lichens are a ubiquitous terrestrial symbiosis of fungi with photoautotrophic microorganisms. The identification of the hosted photoautotrophs is notoriously difficult. Molecular data to clarify evolutionary relationships on the involved algal and cyanobacterial lineages are accumulating, but the assignment to species is challenging for various reasons. One of the challenges is the limited knowledge on the alpha diversity of photoautotrophs. New lineages are being discovered with increasing amounts of sequencing. Identification tools could incorporate these aspects, by routinely updating the assignment process. We propose the establishment of a classification tool using algal sequence data from public databases

European Union expansion and migration

This paper concisely reviews what we know about the experience of an enlarging European Union with free movement of workers within its borders. We focus on the two most recent, Eastern, enlargement waves of 2004 and 2007. We first assess the actual migration flows following the enlargements against the pre-enlargement expectations and perceptions. We then review the effects of these flows on the labor markets of receiving as well as sending countries. We conclude that the available evidence does not indicate negative effects on the receiving countries’ labor markets or welfare systems. From the sending countries’ perspective the risks of out-migration lie in skill shortages in affected occupations or sectors as well as the potential (in)stability of their public finances, whereas the potential benefits may materialize through brain circulation. Overall, free mobility can be described as one of the key achievements, and success stories, of European integration

Addressing the Shortcomings of Traditional Multiple-Choice Tests: Subset Selection Without Mark Deductions

This article presents the results of an empirical study of subset selection tests, which are a generalisation of traditional multiple-choice tests in which test takers are able to express partial knowledge. Similar previous studies have mostly been supportive of subset selection, but the deduction of marks for incorrect responses has been a cause for concern. For the present study, a novel marking scheme based on Akeroyd\u27s “dual response system†was used instead. In Akeroyd\u27s system, which assumes that every question has four answer options, test takers are able to split their single 100% bet on one answer option into two 50% bets by selecting two options, or into four 25% bets by selecting no options. To achieve full subset selection, this idea was extended so that test takers could also split their 100% bet equally between three options. The results indicate increased test reliability (in the sense of measurement consistency), and also increased satisfaction on the part of the test takers. Furthermore, since the novel marking scheme does not in principle lead to either inflated or deflated marks, this makes it easy for educators who currently use traditional multiple-choice tests to switch to using subset selection tests.. Accessed 1,149 times on https://pareonline.net from December 07, 2018 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

The value of leadership practices when there is no one to lead: A nascent entrepreneurship context

Although a considerable amount of literature shows how entrepreneurs develop and utilize social capital to create and grow their ventures, there is scant learning on how nascent entrepreneurs with few ties actually create and utilize social capital to help turn their early ideas into ventures. This paper reveals the role of relational leadership in social capital development and shows how it enhances persistence among very early-stage nascent entrepreneurs, even when they have no employees or partners to lead. Learning from our 18-month in-depth case studies of early-stage nascent entrepreneurs in one European country is used to propose a theory of social capital development in nascent entrepreneurship. Implications for future research and for nascent entrepreneurial practice are discussed