Formation and characteristics of ions and charged aerosol particles in a native Australian Eucalypt forest

International audienceBiogenic aerosol formation is likely to contribute significantly to the global aerosol load. In recent years, new-particle formation has been observed in various ecosystems around the world but hardly any measurements have taken place in the terrestrial Southern Hemisphere. Here, we report the first results of atmospheric ion and charged particle concentrations as well as of new-particle formation in a Eucalypt forest in Tumbarumba, South-East Australia, from July 2005 to October 2006. The measurements were carried out with an Air Ion Spectrometer (AIS) with a size range from 0.34 to 40 nm. The Eucalypt forest was a very strong source of new aerosol particles. Daytime aerosol formation took place on 52% of days with acceptable data, which is 2?3 times as often as in the Nordic boreal zone. Average growth rates for negative/positive 1.5?3 nm particles during these formation events were 2.89/2.68 nmh?1, respectively; for 3-7 nm particles 4.26/4.03, and for 7?20 nm particles 8.90/7.58 nmh?1, respectively. The growth rates for large ions were highest when the air was coming from the native forest which suggests that the Eucalypts were a strong source of condensable vapours. Average concentrations of cluster ions (0.34?1.8 nm) were 2400/1700 cm?3 for negative/positive ions, very high compared to most other measurements around the world. One reason behind these high concentrations could be the strong radon efflux from the soils around the Tumbarumba field site. Furthermore, comparison between night-time and daytime concentrations supported the view that cluster ions are produced close to the surface within the boundary layer also at night but that large ions are mostly produced in daytime. Finally, a previously unreported phenomenon, nocturnal aerosol formation, appeared in 32% of the analysed nights but was clustered almost entirely within six months from summer to autumn in 2006. From January to May, nocturnal formation was 2.5 times as frequent as daytime formation. Therefore, it appears that in summer and autumn, nocturnal production was the major mechanism for aerosol formation in Tumbarumba

Germplasm collection – valuable resources of variability for plant and ear traits in maize breeding

Maize is one of the most important crops, both worldwide and in Romania, and preserving the diversity of the biological material used in the breeding of this plant is of particular importance. The Agricultural Research and Development Station (ARDS) Turda, Romania, inbred lines collection includes both its own genotypes and some obtained as a result of germplasm exchanges with other institutions in the country or abroad. In the present study, 575 lines created at Turda were analysed regarding some traits of the plant (plant height, ear height, total number of leaves, number of tassel branches) and the ear (ear length and weight, number of kernel rows and number of kernels/row). The biological material used in this study shows a great diversity: a medium or high variability coefficient was identified for several of the traits analysed (number of tassel branches, ear height, ear height). Frequency histograms were made for the studied lines, for plant and ear traits. A great variability also was observed in the colours of the anther and silk, but also for kernel type and colour and cob colour

Heavy Ion Carcinogenesis and Human Space Exploration

Prior to the human exploration of Mars or long duration stays on the Earth s moon, the risk of cancer and other diseases from space radiation must be accurately estimated and mitigated. Space radiation, comprised of energetic protons and heavy nuclei, has been show to produce distinct biological damage compared to radiation on Earth, leading to large uncertainties in the projection of cancer and other health risks, while obscuring evaluation of the effectiveness of possible countermeasures. Here, we describe how research in cancer radiobiology can support human missions to Mars and other planets

Subcellular analysis of blood-brain barrier function by micro-impalement of vessels in acute brain slices.

The blood-brain barrier (BBB) is a tightly and actively regulated vascular barrier. Answering fundamental biological and translational questions about the BBB with currently available approaches is hampered by a trade-off between accessibility and biological validity. We report an approach combining micropipette-based local perfusion of capillaries in acute brain slices with multiphoton microscopy. Micro-perfusion offers control over the luminal solution and allows application of molecules and drug delivery systems, whereas the bath solution defines the extracellular milieu in the brain parenchyma. Here we show, that this combination allows monitoring of BBB transport at the cellular level, visualization of BBB permeation of cells and molecules in real-time and resolves subcellular details of the neurovascular unit. In combination with electrophysiology, it permits comparison of drug effects on neuronal activity following luminal versus parenchymal application. We further apply micro-perfusion to the human and mouse BBB of epileptic hippocampi highlighting its utility for translational research and analysis of therapeutic strategies

The impact of the COVID-19 pandemic on European police officers: Stress, demands, and coping resources

Purpose: Facing the COVID-19 pandemic, police officers are confronted with various novel challenges, which might place additional strain on officers. This mixed-method study investigated officers’ strain over a three- month-period after the lockdown. Methods: In an online survey, 2567 police officers (77% male) from Austria, Germany, Switzerland, the Netherlands, and Spain participated at three measurement points per country in spring, 2020. Three-level growth curve models assessed changes in strain and its relation to stressor appraisal, emotion regulation, and pre- paredness through training. To add context to the findings, free response answers about officers’ main tasks, stressors, and crisis measures were coded inductively. Results: On average, officers seemed to tolerate the pandemic with slight decreases in strain over time. Despite substantial variance between countries, 66% of the variance occurred between individuals. Sex, work experience, stressor appraisal, emotion regulation, and preparedness significantly predicted strain. Risk of infection and deficient communication emerged as main stressors. Officers’ reports allowed to derive implications for governmental, organizational, and individual coping strategies during pandemics. Conclusion: Preparing for a pandemic requires three primary paths: 1) enacting unambiguous laws and increasing public compliance through media communication, 2) being logistically prepared, and 3) improving stress regulation skills in police training

Screening of the Romanian maize (Zea mays L.) germplasm for crtRB1 and lcyE alleles enhancing the provitamin A concentration in endosperm

Maize occupies a significant place in the world agriculture. Yellow kernel maize contains mainly non-provitamin A carotenoids: lutein and zeaxanthin. The accumulation of provitamin A carotenoids is regulated by favourable alleles of lcyE and crtRB1 genes and could be used for the enhancement of these carotenoids in the maize grain through breeding. In this study, molecular screening of the Romanian germplasm was performed, looking for favourable alleles of the crtRB1 and lcyE genes, and the level of carotenoids was determined in a few selected lines. A number of 2746 inbred lines from seven research stations were subjected to a PCR amplification of crtRB1 and lcyE genes in order to identify the favourable alleles. It was selected 27 lines carrying the favourable alleles and nine lines with unfavourable alleles (four groups in total), from which total carotenoids, lutein, zeaxanthin, β-cryptoxanthin, β-carotene and retinol equivalents were determined by HPLC. Out of 2746 inbred lines analysed, 23.53% contained one or both genes with favourable alleles. The favourable allele of the crtRB1 gene was the most widespread (584 lines), followed by the lcyE gene (55 lines), while alleles favourable for both genes were detected in only 7 lines. Inbred lines with the favourable allele of the crtRB1 gene showed the highest levels of β-carotene and β-cryptoxanthin, while those with favourable allele of lcyE gene showed a high level of β-cryptoxanthin; the lines with favourable alleles for both genes had a level of β-carotene 60% higher than the lines with two unfavourable alleles

Metal ion-implanted TiN thin films: Induced effects on structural and optical properties

The ion implantation technique has a number of advantages over conventional methods for the improvement of thin films that offer the various possibilities of their use in different industrial and technological fields. Herein, we present the effects of metal ion implantation on the structural and optical properties of TiN thin films. TiN films of 170 nm thickness were grown by d.c. reactive sputtering on Si (100) wafers and then irradiated at 5×1016 ions/cm2 with either Au, Ag, or Cu ions by using two different energies per each implanted metal. The results showed that as deposited TiN crystallizes in form of fcc cubic structure, with the crystallites preferentially oriented along the (111) plane. For all implanted layers the cubic crystallographic structure was preserved, but compared to as deposited TiN the crystallites were smaller and the lattice was contracted. Besides, the surface compositional analysis of as deposited sample showed the coexistence of TiN, TiO2 and TiOxNy phases and this was related to the surface oxidation of the films due to the exposure to air. After implantation, the results were almost similar for all metals, showing an increase in TiO2 contribution and the formation of pure metallic Au and Ag phases, while copper is in the Cu2+ state, which is attributed to Cu(II)-oxide and Cu(OH)2. The microstructural characteristics including defect formation, changes in the crystallite size and lattice contraction, and also growth of different metallic phases during implantations were correlated with the findings of the optical characterization of the implanted films. For as deposited film we found energy gap of 2.91 eV, which was lower than the value typical for TiN. After implantation the gap was shifted to higher energies, while at the visible part of the region, additional energy levels, at photon energies below 2.9 eV were observed. Further, all implanted films showed degraded photocatalytic activity compared to as deposited TiN, among which Cu-implanted samples exhibited the best photocatalytic performances. The lower photocatalytic activity of Au and Ag-implanted films compared to Cu implantations was ascribed to larger structural defects and formation of less favorable electronic states.IX International School and Conference on Photonics : PHOTONICA2023 : book of abstracts; August 28 - September 1, 2023; Belgrad

Weighted STOP-Bang and screening for sleep-disordered breathing

BACKGROUND: STOP-Bang is a tool for predicting the likelihood for sleep-disordered breathing (SDB). In the conventional score, all variables are dichotomous. Our aim was to identify whether modifying the STOP-Bang scoring tool by weighting the variables could improve test characteristics. METHODS: Subjects who participated in the Sleep Heart Health Study (SHHS) were included in this analysis using a derivation dataset (n = 1667) and a validation dataset (n = 4774). In the derivation dataset, each STOP-Bang variable was evaluated using linear regression against the presence of SDB (AHI > 15/h) in order to determine the coefficients that would allow variable weighting. In other models, BMI, age, and neck circumference were entered as continuous variables. The sum of the weighted dichotomous variables yielded a weighted STOP-Bang (wSTOP-Bang). The sum of the weighted-continuous variables yielded a continuous STOP-Bang (cSTOP-Bang). The wSTOP-Bang, cSTOP-Bang, and the conventional STOP-Bang scores were then applied to the validation dataset, and receiver operating characteristic (ROC) curves were constructed. RESULTS: The area under the curve (AUC) for cSTOP-Bang (0.738) was greater than the AUC for conventional STOP-Bang (0.706) and wSTOP-Bang (0.69). The sensitivities for cSTOP-Bang, STOP-Bang, and wSTOP-Bang were similar at 93.2, 93.2, and 93.3 %, respectively. The cSTOP-Bang had a higher specificity (31.8 %) than both STOP-Bang (23.2 %) and wSTOP-Bang (23.6 %). The cSTOP-Bang had a higher likelihood ratio of a positive test (1.36) than both STOP-Bang (1.21) and wSTOP-Bang (1.22). CONCLUSIONS: Modifying the STOP-Bang score by weighting the variables and using continuous variables for BMI, age, and neck circumference can maintain sensitivity while improving specificity, positive likelihood ratio, and area under the receiver operating characteristic curve