Intensification of ice nucleation observed in ocean ship emissions

Shipping contributes primary and secondary emission products to the atmospheric aerosol burden that have implications for climate, clouds, and air quality from regional to global scales. In this study we exam the potential impact of ship emissions with regards to ice nucleating particles. Particles that nucleate ice are known to directly affect precipitation and cloud microphysical properties. We have collected and analyzed particles for their ice nucleating capacity from a shipping channel outside a large Scandinavia port. We observe that ship plumes amplify the background levels of ice nucleating particles and discuss the larger scale implications. The measured ice nucleating particles suggest that the observed amplification is most likely important in regions with low levels of background particles. The Arctic, which as the sea ice pack declines is opening to transit and natural resource exploration and exploitation at an ever increasing rate, is highlighted as such a region.

Epidemiological, genetic, and clinical characterization by age of newly diagnosed acute myeloid leukemia based on an academic population-based registry study (AMLSG BiO)

We describe genetic and clinical characteristics of acute myeloid leukemia (AML) patients according to age from an academic population-based registry. Adult patients with newly diagnosed AML at 63 centers in Germany and Austria were followed within the AMLSG BiO registry (NCT01252485). Between January 1, 2012, and December 31, 2014, data of 3525 patients with AML (45% women) were collected. The median age was 65 years (range 18-94). The comparison of age-specific AML incidence rates with epidemiological cancer registries revealed excellent coverage in patients < 70 years old and good coverage up to the age of 80. The distribution according to the European LeukemiaNet (ELN) risk categorization from 2010 was 20% favorable, 31% intermediate-1, 28% intermediate-2, and 21% adverse. With increasing age, the relative but not the absolute prevalence of patients with ELN favorable and intermediate-1 risk (p < 0.001), with activating FLT3 mutations (p < 0.001), with ECOG performance status < 2 (p < 0.001), and with HCT-CI comorbidity index < 3 (p < 0.001) decreased. Regarding treatment, obesity and favorable risk were associated with an intensive treatment, whereas adverse risk, higher age, and comorbidity index > 0 were associated with non-intensive treatment or best supportive care. The AMLSG BiO registry provides reliable population-based distributions of genetic, clinical, and treatment characteristics according to age.

DNMT3A mutant transcript levels persist in remission and do not predict outcome in patients with acute myeloid leukemia

We investigated the prognostic impact of minimal residual disease (MRD) monitoring in acute myeloid leukemia patients harboring DNA methyltransferase 3A-R882H/-R882C mutations (DNMT3A^mut). MRD was determined by real-time quantitative PCR (RQ-PCR) in 1494 samples of 181 DNMT3A^mut patients. At the time of diagnosis, DNMT3A^mut transcript levels did not correlate with presenting clinical characteristics and concurrent gene mutations as well as the survival end points. In Cox regression analyses, bone marrow (BM) DNMT3A^mut transcript levels (log10-transformed continuous variable) were not associated with the rate of relapse or death. DNMT3A^mut transcript levels were significantly higher in BM than in blood after induction I (P=0.01), induction II (P=0.05), consolidation I (P=0.004) and consolidation II (P=0.008). With regard to the clinically relevant MRD time points, after two cycles of induction and at the end of therapy, DNMT3A^mut transcript levels had no impact on the end point remission duration and overall survival. Of note, only a minority of the patients achieved RQ-PCR negativity, whereas most had constantly high DNMT3A^mut transcript levels, a finding which is consistent with the persistence of clonal hematopoiesis in hematological remission.

Dictionary learning for sparse representation and classification of neural spikes

Spike sorting is the problem of identifying and clustering neurons spiking activity from recorded extracellular electro-physiological data. This is important for experimental neuroscience. Existing approaches to solve this problem consist of three steps: spike detection, feature extraction, and clustering. In our method, we use Fisher discriminant based dictionary learning to learn dictionary, whose sub-dictionaries are class specific, and estimate discriminative sparse coding coefficients by minimizing the within class scatter and maximizing the between class scatter. Both the reconstruction error and coding coefficients are used for clustering the testing data. The dictionary learn the proper features specific to this problem. The proposed method has high reconstruction power and high clustering accuracy of testing data.

Heparin modification of a biomimetic bone matrix modulates osteogenic and angiogenic cell response in vitro

In this study, the effect of heparin-modified collagen type I/hydroxyapatite (HA) nanocomposites on key processes of bone regeneration - osteogenesis and angiogenesis - was characterised in vitro. Two approaches were applied for heparin modification: it was either integrated during material synthesis (in situ) or added to the porous scaffolds after their fabrication (post). Cultivation of human bone marrow-derived stromal cells (hBMSC), in heparin-modified versus heparin-free scaffolds, revealed a positive effect of the heparin modification on their proliferation and osteogenic differentiation. The amount of heparin rather than the method used for modification influenced the cell response favouring proliferation at smaller amount (30 mg/g collagen) and differentiation at larger amount (150 mg/g collagen). A co-culture of human umbilical vein endothelial cells (HUVEC) and osteogenically induced hBMSC was applied for in vitro angiogenesis studies. Pre-vascular networks have formed in the porous structure of scaffolds which were not modified with heparin or modified with a low amount of heparin (30 mg/g collagen). The modification with higher heparin quantities seemed to inhibit tubule formation. Pre-loading of the scaffolds with VEGF influenced formation and stability of the pre-vascular structures depending on the presence of heparin: In heparin-free scaffolds, induction of tubule formation and sprouting was more pronounced whereas heparin-modified scaffolds seemed to promote stabilisation of the pre-vascular structures. In conclusion, the modification of mineralised collagen with heparin by using both approaches was found to modulate cellular processes essential for bone regeneration; the amount of heparin has been identified to be crucial to direct cell responses.

Altered immune reconstitution of B and T cells precedes the onset of clinical symptoms of chronic graft-versus-host disease and is influenced by the type of onset

We analyzed lymphocyte subpopulations and cytokines 3 months after allogeneic hematopoietic stem cell transplantation aiming to identify predictive cellular and serum markers for chronic graft-versus-host disease (cGVHD). Samples of 49 patients (pts) (no cGVHD (n = 14), subsequent quiescent onset (n = 16), de novo onset of cGVHD (n = 19)) were analyzed in the absence of active GVHD by flow cytometry and enzyme-linked immunosorbent assay. All mean absolute cell counts are presented as cells per microliter; relative cell counts are presented as percentage of lymphocytes. Pts with subsequent de novo cGVHD had significantly higher relative and absolute counts of CD4+ T cells including higher absolute counts of CD4+ memory T cells (22.36%; 206.55/μl; 136/μl, respectively) compared to pts with subsequent quiescent onset of cGVHD (12.41%; 83.42/μl; 54.3/μl) and pts without cGVHD (10.55%) with regard to relative counts of CD4+ T cells. Similarly, significantly more relative and absolute regulatory T cell numbers (CD4+FOXP3+) were detected in pts with de novo onset of cGVHD (3.08% and 24.63/μl) compared to those in pts without (1.25% and 9.06/μl) or with quiescent onset of cGVHD (1.15% and 6.91/μl). Finally, relative B cell counts, including naïve and memory B cells, were also significantly decreased in pts developing quiescent cGVHD (0.85, 0.73, 0.12% resp.) when compared to pts with de novo onset (5.61, 5.24, 0.38%). The results demonstrate that alterations in immune reconstitution are already present before onset of clinical symptoms and differ between de novo and quiescent onset of disease.