867 research outputs found
Evolutionary Clustering of Apprentices' Self- Regulated Learning Behavior in Learning Journals
Learning journals are increasingly used in vocational education to foster self-regulated learning and reflective learning practices. However, for many apprentices, documenting working experiences is a difficult task. In this article, we profile apprentices' learning behavior in an online learning journal. Based on a pedagogical framework, we propose a novel multistep clustering pipeline that integrates different learning dimensions into a combined profile. Specifically, the profiles are described in terms of effort, consistency, regularity, help-seeking behavior, and quality of the written entries. Our results on two populations of chef apprentices (183 apprentices) interacting with an online learning journal (over 121K entries) show that our pipeline captures changes in learning patterns over time and yields interpretable profiles that can be related to academic performance. The obtained profiles can be used as a basis for personalized interventions, with the ultimate goal of improving the apprentices' learning experience
Communicating climate knowledge proxies, processes, politics
This forum article is the product of interdisciplinary discussion at a conference on climate histories held inCambridge, United Kingdom, in early 2011, with the specific aim of building a network around the issue of communicating cultural knowledge of environmental change. The lead articles, by Kirsten Hastrup as an anthropologist and Simon Schaffer as a historian of science, highlight the role of agents and proxies. These are followed by five interdisciplinary commentaries, which engage with the lead articles through new ethnographic material, and a set of shorter commentaries by leading scholars of different disciplines. Finally, the lead authors respond to the discussion. In this debate, climate change does not emerge as a single preformed "problem." Rather, different climate knowledges appear as products of particular networks and agencies. Just as the identification of proxies creates agents (ice, mountains, informants) by inserting them into new networks, we hope that these cross-disciplinary exchanges will produce further conversations and new approaches to action. © 2012 by The Wenner-Gren Foundation for Anthropological Research
First trimester myomectomy as an alternative to termination of pregnancy in a woman with a symptomatic uterine leiomyoma: a case report
<p>Abstract</p> <p>Introduction</p> <p>Performing a myomectomy during pregnancy is extremely rare due to the risk of pregnancy loss, hemorrhage and hysterectomy. Favorable outcomes have been demonstrated with select second trimester gravid myomectomies. Literature documenting first trimester surgical management of myomas during pregnancy is scant. Patients with symptomatic myomas failing conservative management in the first trimester may be counseled to abort the pregnancy and then undergo myomectomy. Reports focusing on myomectomy in the first trimester are needed to permit more thorough options counseling for patients failing conservative management in the first trimester.</p> <p>Case presentation</p> <p>A 30-year-old Caucasian primagravid (G1P0) was referred for termination of her pregnancy at 10 weeks due to a 14 cm myoma causing severe pain, constipation and urine retention. Her referring physician planned an interval myomectomy following the abortion. Instead, our patient underwent myomectomy at 11 weeks. Two leiomyomas were successfully removed; she delivered a healthy infant at term.</p> <p>Conclusion</p> <p>Patients in the first trimester should not be counseled that termination followed by myomectomy is the best option for symptomatic myomas, failing conservative treatment. Management should be individualized after taking into account the patient's symptoms, gestational age and the location of the myomas in relation to the placenta. Any field providing women's health services will be impacted by the ability to offer more thorough options counseling for women with refractory myomas in the first trimester.</p
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Sources and characteristics of summertime organic aerosol in the Colorado Front Range: perspective from measurements and WRF-Chem modeling
Abstract. The evolution of organic aerosols (OAs) and their precursors in the boundary layer (BL) of the Colorado Front Range during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ, July–August 2014) was analyzed by in situ measurements and chemical transport modeling. Measurements indicated significant production of secondary OA (SOA), with enhancement ratio of OA with respect to carbon monoxide (CO) reaching 0.085±0.003 µg m−3 ppbv−1. At background mixing ratios of CO, up to  ∼  1.8 µg m−3 background OA was observed, suggesting significant non-combustion contribution to OA in the Front Range. The mean concentration of OA in plumes with a high influence of oil and natural gas (O&G) emissions was  ∼  40 % higher than in urban-influenced plumes. Positive matrix factorization (PMF) confirmed a dominant contribution of secondary, oxygenated OA (OOA) in the boundary layer instead of fresh, hydrocarbon-like OA (HOA). Combinations of primary OA (POA) volatility assumptions, aging of semi-volatile species, and different emission estimates from the O&G sector were used in the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) simulation scenarios. The assumption of semi-volatile POA resulted in greater than a factor of 10 lower POA concentrations compared to PMF-resolved HOA. Including top-down modified O&G emissions resulted in substantially better agreements in modeled ethane, toluene, hydroxyl radical, and ozone compared to measurements in the high-O&G-influenced plumes. By including emissions from the O&G sector using the top-down approach, it was estimated that the O&G sector contributed to  <  5 % of total OA, but up to 38 % of anthropogenic SOA (aSOA) in the region. The best agreement between the measured and simulated median OA was achieved by limiting the extent of biogenic hydrocarbon aging and consequently biogenic SOA (bSOA) production. Despite a lower production of bSOA in this scenario, contribution of bSOA to total SOA remained high at 40–54 %. Future studies aiming at a better emissions characterization of POA and intermediate-volatility organic compounds (IVOCs) from the O&G sector are valuable
FAMIN is a multifunctional purine enzyme enabling the purine nucleotide cycle
Mutations in FAMIN cause arthritis and inflammatory bowel disease in early childhood, and a common genetic variant increases risk for Crohn’s disease and leprosy. We developed an unbiased liquid chromatography mass spectrometry screen for enzymatic activity of this orphan protein. We report that FAMIN phosphorolytically cleaves adenosine into adenine and ribose-1-phosphate. Such activity was considered absent from eukaryotic metabolism. FAMIN and its prokaryotic paralogues additionally have adenosine deaminase, purine nucleoside phosphorylase, and S-methyl-5'-thioadenosine phosphorylase activity, hence combine activities of the namesake enzymes of central purine metabolism. FAMIN enables in macrophages a purine nucleotide cycle (PNC) between adenosine and inosine monophosphate and adenylosuccinate, which consumes aspartate and releases fumarate in a manner involving fatty acid oxidation and ATP-citrate lyase activity. This macrophage PNC synchronises mitochondrial activity with glycolysis by balancing electron transfer to mitochondria, thereby supporting glycolytic activity and promoting oxidative phosphorylation and mitochondrial H+ and phosphate recycling.Includes ERC. Wellcome Trust and MRC
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GPR35 promotes glycolysis, proliferation, and oncogenic signaling by engaging with the sodium potassium pump.
The sodium potassium pump (Na/K-ATPase) ensures the electrochemical gradient of a cell through an energy-dependent process that consumes about one-third of regenerated ATP. We report that the G protein-coupled receptor GPR35 interacted with the α chain of Na/K-ATPase and promotes its ion transport and Src signaling activity in a ligand-independent manner. Deletion of Gpr35 increased baseline Ca2+ to maximal levels and reduced Src activation and overall metabolic activity in macrophages and intestinal epithelial cells (IECs). In contrast, a common T108M polymorphism in GPR35 was hypermorphic and had the opposite effects to Gpr35 deletion on Src activation and metabolic activity. The T108M polymorphism is associated with ulcerative colitis and primary sclerosing cholangitis, inflammatory diseases with a high cancer risk. GPR35 promoted homeostatic IEC turnover, whereas Gpr35 deletion or inhibition by a selective pepducin prevented inflammation-associated and spontaneous intestinal tumorigenesis in mice. Thus, GPR35 acts as a central signaling and metabolic pacesetter, which reveals an unexpected role of Na/K-ATPase in macrophage and IEC biology.European Research Council Consolidator Grant n° 648889 to A.K.
Scientia Fellowship (FP7-PEOPLE-2013-COFUND) grant agreement n° 609020 to G.S.
Addenbrooke’s Charitable Trust (ACT 25/16A) to J.E.E.
UniNA and Compagnia Di San Paolo ‘STAR program for young researchers’ fellowship to E.P
A Spaetzle-like role for Nerve Growth Factor β in vertebrate immunity to Staphylococcus aureus
Many key components of innate immunity to infection are shared between Drosophila and humans. However, the fly Toll ligand Spaetzle is not thought to have a vertebrate equivalent. We have found that the structurally related cystine-knot protein, nerve growth factor β (NGFβ), plays an unexpected Spaetzle-like role in immunity to Staphylococcus aureus infection in chordates. Deleterious mutations of either human NGFβ or its high-affinity receptor tropomyosin-related kinase receptor A (TRKA) were associated with severe S. aureus infections. NGFβ was released by macrophages in response to S. aureus exoproteins through activation of the NOD-like receptors NLRP3 and NLRC4 and enhanced phagocytosis and superoxide-dependent killing, stimulated proinflammatory cytokine production, and promoted calcium-dependent neutrophil recruitment. TrkA knockdown in zebrafish increased susceptibility to S. aureus infection, confirming an evolutionarily conserved role for NGFβ-TRKA signaling in pathogen-specific host immunity
Potential climatic transitions with profound impact on Europe
We discuss potential transitions of six climatic subsystems with large-scale impact on Europe, sometimes denoted as tipping elements. These are the ice sheets on Greenland and West Antarctica, the Atlantic thermohaline circulation, Arctic sea ice, Alpine glaciers and northern hemisphere stratospheric ozone. Each system is represented by co-authors actively publishing in the corresponding field. For each subsystem we summarize the mechanism of a potential transition in a warmer climate along with its impact on Europe and assess the likelihood for such a transition based on published scientific literature. As a summary, the ‘tipping’ potential for each system is provided as a function of global mean temperature increase which required some subjective interpretation of scientific facts by the authors and should be considered as a snapshot of our current understanding. <br/
Tropospheric HONO distribution and chemistry in the southeastern US
Here we report the measurement results of nitrous acid (HONO) and a suite of relevant parameters on the NCAR C-130 research aircraft in the southeastern US during the NOMADSS 2013 summer field study. The daytime HONO concentration ranged from low parts per trillion by volume (pptv) in the free troposphere (FT) to mostly within 5-15 pptv in the background planetary boundary layer (PBL). There was no discernible vertical HONO gradient above the lower flight altitude of 300m in the PBL, and the transport of ground surface HONO was not found to be a significant contributor to the tropospheric HONO budget. The total in situ HONO source mean (+/- 1 SD) was calculated as 53 (+/- 21) pptv h(-1) during the day. The upper-limit contribution from NOx-related reactions was 10 (+/- 5) pptv h(-1), and the contribution from photolysis of particulate nitrate (pNO(3)) was 38 (+/- 23) pptv h(-1), based on the measured pNO(3) concentrations and the median pNO(3) photolysis rate constant of 2.0 x 10 4 s(-1) determined in the laboratory using ambient aerosol samples. The photolysis of HONO contributed to less than 10% of the primary OH source. However, a recycling NOx source via pNO(3) photolysis was equivalent to similar to 2.3 x 10(-6) molm(-2) h(-1) in the air column within the PBL, a considerable supplementary NOx source in the low-NOx background area. Up to several tens of parts per trillion by volume of HONO were observed in power plant and urban plumes during the day, mostly produced in situ from precursors including NOx and pNO(3). Finally, there was no observable accumulation of HONO in the nocturnal residual layer and the nocturnal FT in the background southeastern US, with an increase in the HONO / NOx ratio ofPeer reviewe
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