ALBERT

Description: Nitrogen oxides, released from fossil fuel use and other combustion processes, affect air quality and climate. From the mid-1990s onward, nitrogen dioxide (NO 2 ) has been monitored from space, and since 2004 with relatively high spatial resolution by the Ozone Monitoring Instrument. Strong upward NO 2 trends have been observed over South and East Asia and the Middle East, in particular over major cities. We show, however, that a combination of air quality control and political factors, including economical crisis and armed conflict, has drastically altered the emission landscape of nitrogen oxides in the Middle East. Large changes, including trend reversals, have occurred since about 2010 that could not have been predicted and therefore are at odds with emission scenarios used in projections of air pollution and climate change in the early 21st century.

Description: Given the high spatial variability of soil moisture content (SMC), direct comparison and integration of observations from different sources and measurement scales is becoming a major challenge. We have developed a spatial upscaling method for SMC that enables the direct combination of in situ measurements and remotely sensed data. The approach is based on the fact that spatial soil moisture patterns are related to ancillary features like topography, land cover, and soil type. This study used in situ data from a well-equipped research site in the northern Italian Alps. One of the main goals was to enable the use of these data for the validation of the NASA Soil Moisture Active Passive (SMAP) products. Dealing with medium- to coarse-resolution satellite imagery, especially in mountain areas, requires compensating for different measurement scales. The study approach was assessed based on Envisat advanced synthetic aperture radar (ASAR) data, which were resampled to reproduce the spatial scale of the SMAP data. Results show that the representativeness of in situ data, with respect to the 3- by 3-km SMAP pixel scale, can be improved significantly—direct correlation between SMC and satellite backscatter was improved from R = 0.05 to 0.28; furthermore, the error of the estimated SMC was improved from RMSE = 0.12 to 0.03 m 3 m –3 . This leads to more accurate reference data, which can help to improve the retrieval of SMC from remotely sensed imagery.

Description: Questions What are the primary biotic and abiotic factors driving composition and abundance of naturally regenerated tree seedlings across forest landscapes of Maine? Do seedling species richness (SR) and density (SD) decrease with improved growing conditions (climate and soil), but increase with increased diversity of overstorey composition and structure? Does partial harvesting disproportionately favour relative dominance of shade-intolerant hardwoods (PIHD) over shade-tolerant softwoods (PTSD)? Location Forest landscapes across the diverse eco-regions and forest types of Maine, USA. Methods This study used USDA Forest Service Forest Inventory Analysis permanent plots ( n  = 10 842), measured every 5 yr since 1999. The best models for each response variable (SR, SD, PIHD and PTSD) were developed based on AIC and biological interpretability, while considering 35 potential explanatory variables incorporating climate, soil, site productivity, overstorey structure and composition, and past harvesting. Results Mean annual temperature was the most important abiotic factor, whereas overstorey tree size diversity was the most important biotic factor for SR and SD. Both mean annual temperature and overstorey tree size diversity had a curvilinear relationship with SR and SD. Average overstorey shade tolerance and percentage tolerant softwood basal area in the overstorey were the top predictor variables of PIHD and PTSD , respectively. Partial harvesting favoured PIHD but not PTSD. Conclusions This is one of the first studies to comprehensively evaluate a number of factors influencing naturally established tree seedlings at a broad landscape scale in the Northern Forest region of the eastern USA and Canada. Despite limitations associated with relatively small plot size, large seedling size class and lack of direct measurements of light, water and nutrients, this study documents the influence of these factors amid high variability associated with patterns of natural regeneration. The curvilinear relationship between mean annual temperature with SR and SD supports the argument that species richness and abundance usually have unimodal relationships with productivity indicators, whereas the curvilinear relationship between overstorey tree size diversity and SR and SD suggest that moderate overstorey diversity incorporates multiple species as well as higher seedling individuals. Broad landscape-scale variation in tree seedling composition and abundance in the diverse forests of Maine, USA were examined. Results indicated that mean annual temperature had the strongest influence on both seedling species richness and density, suggesting potential tree seedling sensitivity to climate change in the forests of Maine. However, a variety of other factors were observed to influence tree seedling dynamics.

Description: A plasma spectrometer design based on advances in lithography and microchip stacking technologies is described. A series of curved plate energy analyzers, with an integrated collimator, is etched into a silicon wafer. Tests of spectrometer elements, the energy analyzer and collimator, were performed with a 5 keV electron beam. The measured collimator transmission and energy selectivity were in good agreement with design targets. A single wafer element could be used as a plasma processing or fusion first wall diagnostic.

Description: As heated debates about the origin of rice domestication and cultivation in southern and eastern China continuously attract attention of the broad scientific community, new evidence for early rice exploitation from the regions located outside the core area of domestication, the lower Yangtze, are very important. Here, we present new archaeobotanical results of plant macrofossil and phytolith analyses, including directly dated rice grains from the sites of Dongpan (4030–3820 cal. BC) and Beiqian (3700–2900 cal. BC). These results fill (at least partly) an existing gap between the c . 8000-year-old rice remains from the Early Neolithic Houli Culture ( c . 6500–5500 BC) sites north of the Shandong Highlands and the Longshan Culture ( c . 2600–1900 BC) sites, where intensive rice agriculture was practiced. Neither rice nor millet made substantial contribution to the plant macrofossil assemblage at Dongpan, while broomcorn (and to a lesser extent foxtail) millet contributed up to 75% to the macrofossil assemblage at Beiqian. This increase can be interpreted as a major change in regional subsistence from strongly relying on wild resources and small scale cultivation during the Beixin Cultural period to a millet-based economy during the Dawenkou Culture.

Description: Current therapy approaches in melanoma targeting have met with the development of resistance and tumour recurrence with a more aggressive phenotype. In a quest for alternative therapy targets, we had previously identified Signal Sequence Receptor 2 (SSR2) as a gene with high expression in a subgroup of human primary melanomas. Now we show that SSR2 exerts a prosurvival functionality in human melanoma cells and that high expression levels of SSR2 are associated with an unfavourable disease outcome in primary melanoma patients. Consistent with SSR’s role in translocation of proteins from the ribosome across the endoplasmic reticulum (ER) membrane, our data supports induction of SSR2 as a part of the ER stress response. This response included SSR2 upregulation upon development of therapy resistance to BRAF inhibitors, as well as the dependency of cell survival of BRAF inhibitor-resistant melanoma cells on SSR2. Complementary gain and loss of function data showed the Unfolded Protein Response (UPR) to ER stress as an inducer of SSR2 via transcriptional regulation through X-Box Binding Protein 1s (XBP1s) and support an ER stress-UPR-Transcription Factor XBP1s-SSR2 response axis in human melanocytic cells. Together with its dispensability for survival in normal human cells, these data propose SSR2 as a potential therapeutic target in (therapy-resistant) human melanoma.

Description: The authors have applied positron annihilation spectroscopy to study the vacancy defects in undoped and Si-doped Ga 2 O 3 thin films. The results show that Ga vacancies are formed efficiently during metal-organic vapor phase epitaxy growth of Ga 2 O 3 thin films. Their concentrations are high enough to fully account for the electrical compensation of Si doping. This is in clear contrast to another n -type transparent semiconducting oxide In 2 O 3 , where recent results show that n -type conductivity is not limited by cation vacancies but by other intrinsic defects such as O i .

Description: CpG dinucleotides are known to play a crucial role in regulatory domains, affecting gene expression in their natural context. Here, we demonstrate that intragenic CpG frequency and distribution impacts transgene and genomic gene expression levels in mammalian cells. As shown for the Macrophage Inflammatory Protein 1α, de novo RNA synthesis correlates with the number of CpG dinucleotides, whereas RNA splicing, stability, nuclear export and translation are not affected by the sequence modification. Differences in chromatin accessibility in vivo and altered nucleosome positioning in vitro suggest that increased CpG levels destabilize the chromatin structure. Moreover, enriched CpG levels correlate with increased RNA polymerase II elongation rates in vivo. Interestingly, elevated CpG levels particularly at the 5' end of the gene promote efficient transcription. We show that this is a genome-wide feature of highly expressed genes, by identifying a domain of ~700 bp with high CpG content downstream of the transcription start site, correlating with high levels of transcription. We suggest that these 5' CpG domains are required to distort the chromatin structure and to increase gene activity.

Description: Unconformity-related hydrothermal ore deposits typically form by mixing of hot, deep, rock-buffered basement brines and cooler fluids derived from the surface or overlying sediments. Current models invoking simultaneous downward and upward flow of the mixing fluids are inconsistent with fluid overpressure indicated by fracturing and brecciation, fast fluid flow suggested by thermal disequilibrium, and small-scale fluid composition variations indicated by fluid inclusion analyses. We propose a new model where fluids first descend, then evolve while residing in pores and later ascend. We use the hydrothermal ore deposits of the Schwarzwald district in southwest Germany as an example. Oldest fluids reach the greatest depths, where long residence times and elevated temperatures allow them to equilibrate with their host rock, to reach high salinity, and to scavenge metals. Youngest fluids can only penetrate to shallower depths and can (partially) retain their original signatures. When fluids are released from different levels of the crustal column, these fluids mix during rapid ascent in hydrofractures to form hydrothermal ore deposits. Mixing from below during ascent provides a viable hydromechanical mechanism to explain the common phenomenon of mixed shallow and deep fluids in the formation of hydrothermal ore deposits.