Epilobium ciliatum Raf., a new plant invader in Slovenia and Croatia

The North American invasive species Epilobium ciliatum Raf. was recently recorded for the first time in Slovenia and Croatia. The most reliable character with which to distinguish E. ciliatum from all native European Epilobium species is the presence of conspicuous longitudinal white stripes on the seed testa. If seeds are not available, E. ciliatum may easily be misidentified as E. roseum. With fieldwork and revision of herbarium material we ascertained that the invasion towards the territory discussed came from the north, which is in agreement with the north west to south east direction of the spread in Europe. At least in Eastern Slovenia E. ciliatum has already become an important member of ruderal plant communities. Rapid spreading and naturalization as in the case of E. ciliatum can give rise to concern that it will replace some indigenous species with a similar ecology or hybridise and so by introgression cause »genetic« pollution of native relatives’ populations. Further spread to the south and east is expected

Morphometric recognition of Hordeum murinum L. subspecies in Slovenia

Morphometric analysis of Slovenian material belonging to Hordeum murinum ssp. leporinum and type subspecies confirmed some of already reported distinguishing characters, but majority of them were not measured precisely before. After revision of herbarium material based on results, about 9% of sheets are still somehow »intermediate«, H. murinum ssp. leporinum is more common in Submediterranean part with some scaterred populations in continental Slovenia and the type subspecies occurr all over Slovenia in lowland ruderal places. Detailed determination key is provided based on results

The effect of hot days on occupational heat stress in the manufacturing industry: implications for workers' well-being and productivity

Climate change is expected to exacerbate heat stress at the workplace in temperate regions, such as Slovenia. It is therefore of paramount importance to study present and future summer heat conditions and analyze the impact of heat on workers. A set of climate indices based on summer mean (Tmean) and maximum (Tmax) air temperatures, such as the number of hot days (HD: Tmax above 30 °C), and Wet Bulb Globe Temperature (WBGT) were used to account for heat conditions in Slovenia at six locations in the period 1981–2010. Observed trends (1961–2011) of Tmean and Tmax in July were positive, being larger in the eastern part of the country. Climate change projections showed an increase up to 4.5 °C for mean temperature and 35 days for HD by the end of the twenty-first century under the high emission scenario. The increase in WBGT was smaller, although sufficiently high to increase the frequency of days with a high risk of heat stress up to an average of a third of the summer days. A case study performed at a Slovenian automobile parts manufacturing plant revealed non-optimal working conditions during summer 2016 (WBGT mainly between 20 and 25 °C). A survey conducted on 400 workers revealed that 96% perceived the temperature conditions as unsuitable, and 56% experienced headaches and fatigue. Given these conditions and climate change projections, the escalating problem of heat is worrisome. The European Commission initiated a program of research within the Horizon 2020 program to develop a heat warning system for European workers and employers, which will incorporate case-specific solutions to mitigate heat stress.The work was supported by the European Union Horizon 2020 Research and Innovation Action (Project number 668786: HEATSHIELD)

Epilobium ciliatum Raf., a new plant invader in Slovenia and Croatia

The North American invasive species Epilobium ciliatum Raf. was recently recorded for the first time in Slovenia and Croatia. The most reliable character with which to distinguish E. ciliatum from all native European Epilobium species is the presence of conspicuous longitudinal white stripes on the seed testa. If seeds are not available, E. ciliatum may easily be misidentified as E. roseum. With fieldwork and revision of herbarium material we ascertained that the invasion towards the territory discussed came from the north, which is in agreement with the north west to south east direction of the spread in Europe. At least in Eastern Slovenia E. ciliatum has already become an important member of ruderal plant communities. Rapid spreading and naturalization as in the case of E. ciliatum can give rise to concern that it will replace some indigenous species with a similar ecology or hybridise and so by introgression cause »genetic« pollution of native relatives’ populations. Further spread to the south and east is expected

Synecology of Cutandia maritima (L.) Barbey, a rare psammophytic species along the Montenegrin Coast (East Adriatic Coast)

© by Danijela Stešević 2017. Cutandia maritima is a circum-Mediterranean species that inhabits sandy dunes along the coast line. It is fairly frequent on the western Adriatic coast but fairly rare and possibly even non-native in the east. In Croatia, it was discovered in 1990 in Crnika Bay on the island of Rab, which was considered until 2005 to be the only site on the eastern Adriatic coast from the Gulf of Trieste in the north to Corfu in the south. In 2009, the species was briefly reported for Velika plaža (Long Beach) in Ulcinj (Montenegro) but without details about the habitat type and synecology. The aim of this paper is thus to provide a deeper insight into the ecology and synecology of C. maritima in the eastern Adriatic part of the distribution area. On Velika plaža in Ulcinj, the species was found along the whole sea-inland gradient of sand dunes, in various types of vegetation: [1210] - annual vegetation of drift lines, [2110] - embryonic shifting dunes, [2120] - shifting dunes with Ammophila arenaria (white dunes), [2220] - dunes with Euphorbia terracina, [2130∗] - fixed coastal dunes with herbaceous vegetation (grey dunes), and also [2190] - humid dune slacks

A Robust PCA Algorithm for Building Representations from Panoramic Images

Appearance-based modeling of objects and scenes using PCA has been successfully applied in many recognition tasks. Robust methods which have made the recognition stage less susceptible to outliers, occlusions, and varying illumination have further enlarged the domain of applicability. However, much less research has been done in achieving robustness in the learning stage. In this paper, we propose a novel robust PCA method for obtaining a consistent subspace representation in the presence of outlying pixels in the training images. The method is based on the EM algorithm for estimation of principal subspaces in the presence of missing data. By treating the outlying points as missing pixels, we arrive at a robust PCA representation. We demonstrate experimentally that the proposed method is efficient. In addition, we apply the method to a set of panoramic images to build a representation that enables surveillance and view-based mobile robot localization

A Robust PCA Algorithm for Building Representations from Panoramic Images

Appearance-based modeling of objects and scenes using PCA has been successfully applied in many recognition tasks. Robust methods which have made the recognition stage less susceptible to outliers, occlusions, and varying illumination have further enlarged the domain of applicability. However, much less research has been done in achieving robustness in the learning stage. In this paper, we propose a novel robust PCA method for obtaining a consistent subspace representation in the presence of outlying pixels in the training images. The method is based on the EM algorithm for estimation of principal subspaces in the presence of missing data. By treating the outlying points as missing pixels, we arrive at a robust PCA representation. We demonstrate experimentally that the proposed method is efficient. In addition, we apply the method to a set of panoramic images to build a representation that enables surveillance and view-based mobile robot localization

Break zones in the distributions of alleles and species in alpine plants

Aim  We test for the congruence between allele-based range boundaries (break zones) in silicicolous alpine plants and species-based break zones in the silicicolous flora of the European Alps. We also ask whether such break zones coincide with areas of large elevational variation. Location  The European Alps. Methods  On a regular grid laid across the entire Alps, we determined areas of allele- and species-based break zones using respective clustering algorithms, identifying discontinuities in cluster distributions (breaks), and quantifying integrated break densities (break zones). Discontinuities were identified based on the intra-specific genetic variation of 12 species and on the floristic distribution data from 239 species, respectively. Coincidence between the two types of break zones was tested using Spearman’s correlation. Break zone densities were also regressed on topographical complexity to test for the effect of elevational variation. Results  We found that two main break zones in the distribution of alleles and species were significantly correlated. Furthermore, we show that these break zones are in topographically complex regions, characterized by massive elevational ranges owing to high mountains and deep glacial valleys. We detected a third break zone in the distribution of species in the eastern Alps, which is not correlated with topographic complexity, and which is also not evident from allelic distribution patterns. Species with the potential for long-distance dispersal tended to show larger distribution ranges than short-distance dispersers. Main conclusions  We suggest that the history of Pleistocene glaciations is the main driver of the congruence between allele-based and species-based distribution patterns, because occurrences of both species and alleles were subject to the same processes (such as extinction, migration and drift) that shaped the distributions of species and genetic lineages. Large elevational ranges have had a profound effect as a dispersal barrier for alleles during post-glacial immigration. Because plant species, unlike alleles, cannot spread via pollen but only via seed, and thus disperse less effectively, we conclude that species break zones are maintained over longer time spans and reflect more ancient patterns than allele break zones