157 research outputs found
Eight years of sub-micrometre organic aerosol composition data from the boreal forest characterized using a machine-learning approach
The Station for Measuring Ecosystem-Atmosphere Relations (SMEAR) II, located within the boreal forest of Finland, is a unique station in the world due to the wide range of long-term measurements tracking the Earth-atmosphere interface. In this study, we characterize the composition of organic aerosol (OA) at SMEAR II by quantifying its driving constituents. We utilize a multi-year data set of OA mass spectra measured in situ with an Aerosol Chemical Speciation Monitor (ACSM) at the station. To our knowledge, this mass spectral time series is the longest of its kind published to date. Similarly to other previously reported efforts in OA source apportionment from multi-seasonal or multi-annual data sets, we approached the OA characterization challenge through positive matrix factorization (PMF) using a rolling window approach. However, the existing methods for extracting minor OA components were found to be insufficient for our rather remote site. To overcome this issue, we tested a new statistical analysis framework. This included unsupervised feature extraction and classification stages to explore a large number of unconstrained PMF runs conducted on the measured OA mass spectra. Anchored by these results, we finally constructed a relaxed chemical mass balance (CMB) run that resolved different OA components from our observations. The presented combination of statistical tools provided a data-driven analysis methodology, which in our case achieved robust solutions with minimal subjectivity. Following the extensive statistical analyses, we were able to divide the 2012-2019 SMEAR II OA data (mass concentration interquartile range (IQR): 0.7, 1.3, and 2.6 mu gm(-3)) into three sub-categories - low-volatility oxygenated OA (LV-OOA), semi-volatile oxygenated OA (SV-OOA), and primary OA (POA) - proving that the tested methodology was able to provide results consistent with literature. LV-OOA was the most dominant OA type (organic mass fraction IQR: 49 %, 62 %, and 73 %). The seasonal cycle of LV-OOA was bimodal, with peaks both in summer and in February. We associated the wintertime LV-OOA with anthropogenic sources and assumed biogenic influence in LV-OOA formation in summer. Through a brief trajectory analysis, we estimated summertime natural LV-OOA formation of tens of ngm 3 h 1 over the boreal forest. SV-OOA was the second highest contributor to OA mass (organic mass fraction IQR: 19 %, 31 %, and 43 %). Due to SV-OOA's clear peak in summer, we estimate biogenic processes as the main drivers in its formation. Unlike for LV-OOA, the highest SV-OOA concentrations were detected in stable summertime nocturnal surface layers. Two nearby sawmills also played a significant role in SV-OOA production as also exemplified by previous studies at SMEAR II. POA, taken as a mix of two different OA types reported previously, hydrocarbon-like OA (HOA) and biomass burning OA (BBOA), made up a minimal OA mass fraction (IQR: 2 %, 6 %, and 13 %). Notably, the quantification of POA at SMEAR II using ACSM data was not possible following existing rolling PMF methodologies. Both POA organic mass fraction and mass concentration peaked in winter. Its appearance at SMEAR II was linked to strong southerly winds. Similar wind direction and speed dependence was not observed among other OA types. The high wind speeds probably enabled the POA transport to SMEAR II from faraway sources in a relatively fresh state. In the event of slower wind speeds, POA likely evaporated and/or aged into oxidized organic aerosol before detection. The POA organic mass fraction was significantly lower than reported by aerosol mass spectrometer (AMS) measurements 2 to 4 years prior to the ACSM measurements. While the co-located long-term measurements of black carbon supported the hypothesis of higher POA loadings prior to year 2012, it is also possible that short-term (POA) pollution plumes were averaged out due to the slow time resolution of the ACSM combined with the further 3 h data averaging needed to ensure good signal-to-noise ratios (SNRs). Despite the length of the ACSM data set, we did not focus on quantifying long-term trends of POA (nor other components) due to the high sensitivity of OA composition to meteorological anomalies, the occurrence of which is likely not normally distributed over the 8-year measurement period. Due to the unique and realistic seasonal cycles and meteorology dependences of the independent OA subtypes complemented by the reasonably low degree of unexplained OA variability, we believe that the presented data analysis approach performs well. Therefore, we hope that these results encourage also other researchers possessing several-yearlong time series of similar data to tackle the data analysis via similar semi- or unsupervised machine-learning approaches. This way the presented method could be further optimized and its usability explored and evaluated also in other environments.Peer reviewe
Earthworms and mesofauna from an isolated, alkaline chemical waste site in Northwest England
Post-industrial sites across Europe may have developed over periods in excess of a century, often leading to poor nutrient soils with noxious constituents and extreme pH values. One such site, Nob End (Bolton, UK), a toxic tip created in the 1800s from a sodium carbonate factory, represents an âisland of alkalinity in an acidic seaâ where the weathering process (from pH 12) has provided a suitable environment for a rich alkali-loving flora and hence, deserving its designation as a Site of Special Scientific Interest. Despite their importance, the belowground communities have not been investigated and for this reason, in this study, we explored how soil macro- and mesofauna communities respond to extreme pH values in a system that has also experienced recent changes in management practices. As expected, earthworms, mites, insects and woodlice numbers were significantly higher and the community diversity enriched at the (now pH 8) alkaline sites, whereas in areas where acidic boiler waste was historically deposited, enchytraeids, collembolans and dipteran larvae populations dominated the soil communities. Surprisingly, site management (cutting back of scrub) in the alkaline soil areas had a significant positive effect on soil macro-fauna by promoting numbers and biomass, but severely reduced the microarthropod populations. A transect investigation across an increasing pH gradient (from 4.5 to 8.0) was mirrored by a rise in earthworm numbers and species richness. Earthworms were further investigated surrounding the site, seeking potential sources of colonisation, with the majority of species at Nob End also present in adjacent non-industrially-influenced areas. This work demonstrates that soil fauna can ultimately colonise extreme edaphic conditions and these extreme environments have not prompted the development of specific faunal communities. As management of above-ground communities significantly influenced soil invertebrate communities, this could represent an important restoration practice to improve soil structure and fertility at this polluted site
A minor role of asparaginase in predisposing to cerebral venous thromboses in adult acute lymphoblastic leukemia patients
Cerebral venous thrombosis (CVT) covers up to a third of all venous thromboses (VTs) detected in patients with acute lymphoblastic leukemia (ALL). It usually hampers patients' lives and may also endanger efficient leukemia treatment. Although many factors have been suggested to account for an elevated risk of VTs in patients with ALL, there still is a lack of studies focusing on CVTs and especially in the setting of adult ALL patients. We studied in our retrospective population-based cohort the occurrence, characteristics, as well as risk factors for VTs in 186 consecutively diagnosed Finnish adult ALL patients treated with a national pediatric-inspired treatment protocol ALL2000. In the risk factor analyses for VTs we found a distinction of the characteristics of the patients acquiring CVT from those with other kinds of VTs or without thrombosis. In contrast to previous studies we were also able to compare the effects of asparaginase in relation to CVT occurrence. Notably, more than half of the CVTs were diagnosed prior the administration of asparaginase which accentuates the role of other risk factors on the pathophysiology of CVT compared to truncal or central venous line (CVL) VTs in adult ALL patients
Compressive stress-mediated p38 activation required for ER alpha plus phenotype in breast cancer
Breast cancer is now globally the most frequent cancer and leading cause of women's death. Two thirds of breast cancers express the luminal estrogen receptor-positive (ER alpha + ) phenotype that is initially responsive to antihormonal therapies, but drug resistance emerges. A major barrier to the understanding of the ER alpha-pathway biology and therapeutic discoveries is the restricted repertoire of luminal ER alpha + breast cancer models. The ER alpha + phenotype is not stable in cultured cells for reasons not fully understood. We examine 400 patient-derived breast epithelial and breast cancer explant cultures (PDECs) grown in various three-dimensional matrix scaffolds, finding that ER alpha is primarily regulated by the matrix stiffness. Matrix stiffness upregulates the ER alpha signaling via stress-mediated p38 activation and H3K27me3-mediated epigenetic regulation. The finding that the matrix stiffness is a central cue to the ER alpha phenotype reveals a mechanobiological component in breast tissue hormonal signaling and enables the development of novel therapeutic interventions. Subject terms: ER-positive (ER + ), breast cancer, ex vivo model, preclinical model, PDEC, stiffness, p38 SAPK. Reliable luminal estrogen receptor (ER alpha+) breast cancer models are limited. Here, the authors use patient derived breast epithelial and breast cancer explant cultures grown in several extracellular matrix scaffolds and show that ER alpha expression is regulated by matrix stiffness via stress-mediated p38 activation and H3K27me3-mediated epigenetic regulation.Peer reviewe
Robust architecture for distributed intelligence in an IP-based mobile wide-area surveillance system
Thrombolysis in stroke patients with elevated inflammatory markers.
OBJECTIVE
To investigate the prognostic value of white blood cell count (WBC) on functional outcome, mortality and bleeding risk in stroke patients treated with intravenous thrombolysis (IVT).
METHODS
In this prospective multicenter study from the TRISP registry, we assessed the association between WBC on admission and 3-month poor outcome (modified Rankin Scale 3-6), mortality and occurrence of symptomatic intracranial hemorrhage (sICH; ECASS-II-criteria) in IVT-treated stroke patients. WBC was used as continuous and categorical variable distinguishing leukocytosis (WBCâ>â10âĂâ109/l) and leukopenia (WBCââ10 mg/l) on outcomes.
RESULTS
Of 10,813 IVT-treated patients, 2527 had leukocytosis, 112 leukopenia and 8174 normal WBC. Increasing WBC (by 1âĂâ109/l) predicted poor outcome (ORadjusted 1.04[1.02-1.06]) but not mortality and sICH. Leukocytosis was independently associated with poor outcome (ORadjusted 1.48[1.29-1.69]) and mortality (ORadjusted 1.60[1.35-1.89]) but not with sICH (ORadjusted 1.17[0.94-1.45]). Leukopenia did not predict any outcome. In a subgroup, combined leukocytosis and elevated CRP had the strongest association with poor outcome (ORadjusted 2.26[1.76-2.91]) and mortality (ORadjusted 2.43[1.86-3.16]) when compared to combined normal WBC and CRP.
CONCLUSION
In IVT-treated patients, leukocytosis independently predicted poor functional outcome and death. Bleeding complications after IVT were not independently associated with leukocytosis
Reframing gender and feminist knowledge construction in marketing and consumer research: missing feminisms and the case of men and masculinities
Gender has been theorised and studied in many ways and across different disciplines. Although a number of these theorisations have been recognised and adopted in marketing and consumer research, the significance of feminism in knowledge construction has largely remained what we would call âunfinishedâ. Based on a critical reframing of gender research in marketing and consumer research, in dialogue with feminist theory, this article offers theoretical and practical suggestions for how to reinvigorate these research efforts. The analysis highlights dominant theorisations of gender, relating to gender as variable, difference and role; as fundamental difference and structuring; and as cultural and identity constructions. This reframing emphasises various neglected or âmissing feminismsâ, including queer theory; critical race, intersectional and transnational feminisms; material-discursive feminism; and critical studies on men and masculinities. A more detailed discussion of the latter, as a relatively new, growing and politically contentious area, is further developed to highlight more specifically which feminist and gender theories are mainly in use in marketing and consumer research and which are little or not used. In the light of this, it is argued that marketing and related disciplines have thus far largely neglected several key contemporary gender and feminist theorisations, particularly those that centre on gender power relations. The potential impact of these theoretical frames on transdisciplinary studies in marketing and consumer research and research agenda(s) is discussed
Efficiency of European public higher education institutions: a two-stage multicountry approach
The purpose of this study is to examine efficiency and its determinants in a set of higher education institutions (HEIs) from several European countries by means of non-parametric frontier techniques. Our analysis is based on a sample of 259 public HEIs from 7 European countries across the time period of 2001â2005. We conduct a two-stage DEA analysis (Simar and Wilson in J Economet 136:31â64, 2007), first evaluating DEA scores and then regressing them on potential covariates with the use of a bootstrapped truncated regression. Results indicate a considerable variability of efficiency scores within and between countries. Unit size (economies of scale), number and composition of faculties, sources of funding and gender staff composition are found to be among the crucial determinants of these unitsâ performance. Specifically, we found evidence that a higher share of funds from external sources and a higher number of women among academic staff improve the efficiency of the institution
Soil faunal and structural responses to the settlement of a semi- sedentary earthworm Lumbricus terrestris in an arable clay ïŹeld
We studied the soil community and habitat consequences of introducing a deep-burrowing, sedentary life-style earthworm, Lumbricus terrestris (dew-worm) into arable zero-till clay. Seventeen years after introduction, which was originally aimed at improving the macroporosity and permeability of the heavy clay soil, we returned to the gradient of L. terrestris dispersal (well established, more recent and no settlement) and investigated the temporal development of the ecosystem engineering impacts on different faunal groups (earthworms, enchytraeids and nematodes) and soil porosity. The faunal re- sponses were examined both at L. terrestris midden scale (individual living site) and ïŹeld scale. We found that L. terrestris middens sustained elevated densities of all three faunal groups. In the case of earth- worms, there was evidence for temporal development of the engineering impact as the difference be- tween the midden and non-midden areas was more pronounced in the well-established areas than close to the leading edge of dispersal. The earthworm community composition was not altered at L. terrestris midden sites. The settlement of L. terrestris had no discernible effects on ïŹeld-scale earthworm and nematode abundances, but enchytraeids were practically absent beyond the leading edge of the dispersal. This effect might, however, be partly explained by a gradient of increasing clay content. Soil macroporosity at L. terrestris midden sites did not increase with the age of L. terrestris settlement. Our results suggest that L. terrestris settlement in a clay soil can signiïŹcantly increase the spatial patchiness of soil fauna, but may not, except in the case of enchytraeids, affect their ïŹeld-scale abundances or the macroporosity of the soil in the vicinity of L. terrestris living sites
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