1,500 research outputs found
Long‐Term Responses Of The Kuparuk River Ecosystem To Phosphorus Fertilization
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117218/1/ecy2004854939.pd
Coordinate Descent for Mixed-norm NMF
Nonnegative matrix factorization (NMF) is widely used in a variety of machine learning tasks
involving speech, documents and images. Being able to specify the structure of the matrix factors
is crucial in incorporating prior information. The factors correspond to the feature matrix and
the learnt representation. In particular, we allow an user-friendly specification of sparsity on the
groups of features using the L1/L2 measure. Also, we propose a pairwise coordinate descent
algorithm to minimize the objective. Experimental evidence of the efficacy of this approach is
provided on the ORL faces dataset
Net sediment production of methane, distribution of methanogens and methane-oxidizing bacteria, and utilization of methane-derived carbon in an arctic lake
Our study illustrates that methanogenesis and methane oxidation within the sediments of a small arctic lake are spatially variable, and using an integrated set of approaches, strongly suggests that fine-scale patterns of spatial variability in distribution of methane oxidizing bacteria (MOB) and methanogens are related to the nature of bioturbation and utilization of MOB by Chironomus larvae. Greater net sediment methane production occurred at a lake depth where concentrations of both methanogen and MOB DNA in the sediments were higher. The ratios of MOB/methanogen DNA on tubes and in the sediment supported the hypothesis of microbial gardening of MOB only at the lake depth where net methanogenesis was relatively high. Chironomus hindguts contained higher concentration of methanogen DNA and showed a trend toward higher concentration of MOB DNA compared to foreguts. The underlying mechanism for differential distribution of methanogen and MOB DNA across the gut needs further investigation, but the pattern suggests that the relationship between Chironomus larvae, methanogens, and MOB is more complex than simply feeding on and assimilation of MOB as may be implied by low δ13C of larvae. Vertical distribution into the sediment profile of methanogens and MOB DNA reflects the oxygen regime of the overlying water and was consistent with reports of Chironomus bioturbation activities on particle distribution within the sediment profile
Training Report: South-South collaboration for strengthening capacities in assessing the postharvest physiological deterioration (PPD) of fresh cassava roots and technologies for shelf-life extension.
Leveraging Multilayered “Omics” Data for Atopic Dermatitis: A Road Map to Precision Medicine
Atopic dermatitis (AD) is a complex multifactorial inflammatory skin disease that affects ~280 million people worldwide. About 85% of AD cases begin in childhood, a significant portion of which can persist into adulthood. Moreover, a typical progression of children with AD to food allergy, asthma or allergic rhinitis has been reported (“allergic march” or “atopic march”). AD comprises highly heterogeneous sub-phenotypes/endotypes resulting from complex interplay between intrinsic and extrinsic factors, such as environmental stimuli, and genetic factors regulating cutaneous functions (impaired barrier function, epidermal lipid, and protease abnormalities), immune functions and the microbiome. Though the roles of high-throughput “omics” integrations in defining endotypes are recognized, current analyses are primarily based on individual omics data and using binary clinical outcomes. Although individual omics analysis, such as genome-wide association studies (GWAS), can effectively map variants correlated with AD, the majority of the heritability and the functional relevance of discovered variants are not explained or known by the identified variants. The limited success of singular approaches underscores the need for holistic and integrated approaches to investigate complex phenotypes using trans-omics data integration strategies. Integrating omics layers (e.g., genome, epigenome, transcriptome, proteome, metabolome, lipidome, exposome, microbiome), which often have complementary and synergistic effects, might provide the opportunity to capture the flow of information underlying AD disease manifestation. Overlapping genes/candidates derived from multiple omics types include FLG, SPINK5, S100A8, and SERPINB3 in AD pathogenesis. Overlapping pathways include macrophage, endothelial cell and fibroblast activation pathways, in addition to well-known Th1/Th2 and NFkB activation pathways. Interestingly, there was more multi-omics overlap at the pathway level than gene level. Further analysis of multi-omics overlap at the tissue level showed that among 30 tissue types from the GTEx database, skin and esophagus were significantly enriched, indicating the biological interconnection between AD and food allergy. The present work explores multi-omics integration and provides new biological insights to better define the biological basis of AD etiology and confirm previously reported AD genes/pathways. In this context, we also discuss opportunities and challenges introduced by “big omics data” and their integration
Framework for evaluating the health impact of the scale-up of malaria control interventions on all-cause child mortality in Sub-Saharan Africa
Concerted efforts from national and international partners have scaled up malaria control interventions, including insecticide-treated nets, indoor residual spraying, diagnostics, prompt and effective treatment of malaria cases, and intermittent preventive treatment during pregnancy in sub-Saharan Africa (SSA). This scale-up warrants an assessment of its health impact to guide future efforts and investments; however, measuring malaria-specific mortality and the overall impact of malaria control interventions remains challenging. In 2007, Roll Back Malaria's Monitoring and Evaluation Reference Group proposed a theoretical framework for evaluating the impact of full-coverage malaria control interventions on morbidity and mortality in high-burden SSA countries. Recently, several evaluations have contributed new ideas and lessons to strengthen this plausibility design. This paper harnesses that new evaluation experience to expand the framework, with additional features, such as stratification, to examine subgroups most likely to experience improvement if control programs are working; the use of a national platform framework; and analysis of complete birth histories from national household surveys. The refined framework has shown that, despite persisting data challenges, combining multiple sources of data, considering potential contributions from both fundamental and proximate contextual factors, and conducting subnational analyses allows identification of the plausible contributions of malaria control interventions on malaria morbidity and mortality
Managing diabetes in preschool children
This article is a new chapter in the ISPAD Clinical Practice Consensus Guidelines Compendium. The complete set of guidelines can be found for free download at www.ispad.org. The evidence grading system used in the ISPAD Guidelines is the same as that used by the American Diabetes Association
Does the road to happiness depend on the retirement decision? Evidence from Italy
This study estimates the causal effect of retirement decision on well-being in Italy. To do so, the authors exploit the exogenous variation provided by the changes in the eligibility criteria for pensions that were enacted in Italy in 1995 (Dini’s law) and in 1997 (Prodi’s law, from the names of the prime ministers at the time of their introduction). A sizeable and positive impact of retirement decision is found on satisfaction with leisure time and on frequency of meeting friends. Furthermore, the results are generalized, allowing for the estimation of different moments from different data sources
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