The origin of pine pollen grains captured from air at Calypsobyen, Svalbard

Spitsbergen is the largest island in the Svalbard Archipelago (Norway) that has been permanently populated. The harsh Arctic climate prevents development of large vascular plants such as trees. A two-year aerobiological survey was conducted within the framework of two consecutive polar expeditions (2014 and 2015) in Spitsbergen (Calypsobyen, Bellsund). The air quality was measured continuously from June/July to August using a 7-day volumetric air sampler, Tauber trap and moss specimens. Collected air samples and gravimetric pollen deposits were processed following transfer to sterile laboratory conditions and analyzed with the aid of light microscopy. Days when pine pollen grains were detected in the air were selected for further analysis. Clusters of back-trajectories, computed using the Hybrid Single Particle Lagrangian Integrated Trajectory model in combination with ArcGIS software as well as the Flextra trajectory model, showed the movement of air masses to the sampling location at Hornsund, and thus indicated the likely origin of pollen grains. The GlobCover 2009 and CORINE Land Cover 2012 datasets were employed to establish the distribution of coniferous forests in the areas of interest. Conclusions were drawn based on the analyses of the circulation of air masses, using visualization of global weather conditions forecast to supercomputers. For the first time, we have demonstrated that pine pollen grains occurring in pine-free Spitsbergen, could originate from numerous locations, including Scandinavia, Iceland, Siberia and northern Canada. Pollen grains were transported via air masses for distances exceeding ~2000 km. Both air samples and gravimetric pollen deposits revealed the same pattern of Pinus pollen distributio

Antitumoral effects of attenuated Listeria monocytogenes in a genetically engineered mouse model of melanoma

Attenuated Listeria monocytogenes (Lmat-LLO) represents a valuable anticancer vaccine and drug delivery platform. Here we show that in vitro Lmat-LLO causes ROS production and, in turn, apoptotic killing of a wide variety of melanoma cells, irrespectively of their stage, mutational status, sensitivity to BRAF inhibitors or degree of stemness. We also show that, when administered in the therapeutic setting to Braf/Pten genetically engineered mice, Lmat-LLO causes a strong decrease in the size and volume of primary melanoma tumors, as well as a reduction of the metastatic burden. At the molecular level, we confirm that the anti-melanoma activity exerted in vivo by Lmat-LLO depends also on its ability to potentiate the immune response of the organism against the infected tumor. Our data pave the way to the preclinical testing of listeria-based immunotherapeutic strategies against metastatic melanoma, using a genetically engineered mouse rather than xenograft models

Influence of field and road pattern change on gully development in the Bug River valley side (E Poland)

Causes of dynamic development of a permanent gully dissected in sandy river valley side were presented in this paper. Road and field pattern change conditioned the gully forming during one downpour. A new pattern and crop structure caused fast surface flow on the side. Flow concentration along the road and balks causes dissections of gully escarpments and development of the gully branches

Cathodoluminescence Study of Cd1−x\text{}_{1-x}Mnx\text{}_{x}Te and Zn1−x\text{}_{1-x}Mnx\text{}_{x}Te

The cathodoluminescence spectra for Cd$\text{}_{1-x}$Μn$\text{}_{x}$Te (0 < x ≤ 0.7) and Zn$\text{}_{1-x}$Mn$\text{}_{x}$Te (0 < x ≤ 0.6) at room and liquid nitrogen temperature have been presented and discussed. Especially, the influence of increasing temperature and Mn content on cathodoluminescence spectra. The cathodoluminescence emission in Ζn$\text{}_{1-x}$Mn$\text{}_{x}$Te (Cd$\text{}_{1-x}$Μn$\text{}_{x}$Te) centered at ≈ 1.95 eV (2.0 eV) and ≈ 2.2 eV (2.5 eV) are ascribed to Stokes-shifted $\text{}^{4}$Τ$\text{}_{1}$($\text{}^{4}$G) → $\text{}^{6}$A$\text{}_{1}$($\text{}^{6}$S) and $\text{}^{4}$Τ$\text{}_{2}$($\text{}^{4}$G) → $\text{}^{6}$A$\text{}_{1}$($\text{}^{6}$S) internal transitions of Mn$\text{}^{+2}$ within the 3d$\text{}^{5}$ state, respectively

Allocation and Properties of Iron States in Cd1−x\text{}_{1-x}Fex\text{}_{x}Te in Forbidden Gap Energy Range

The use of different experimental methods (reflectivity, absorption, photoconductivity and cathodoluminescence) allowed us to confirm the existence of the deep donor-like state of iron and present allocation and properties of the iron states in Cd$\text{}_{1-y}$Fe$\text{}_{x}$Te (0 ≤ x ≤ 0.05) at 300 K and 77 K in the forbidden gap energy range. It was concluded that the increase in width of the forbidden gap with the change of temperature from 300 K to 77 K leads mainly to the rise of the energy distance between the donor-like iron state $\text{}^{5}$E and the bottom of the conduction band