Xie S.,9500 Gilman Drive |
Tu Z.,9500 Gilman Drive
International Journal of Computer Vision | Year: 2017
We develop a new edge detection algorithm that addresses two important issues in this long-standing vision problem: (1) holistic image training and prediction; and (2) multi-scale and multi-level feature learning. Our proposed method, holistically-nested edge detection (HED), performs image-to-image prediction by means of a deep learning model that leverages fully convolutional neural networks and deeply-supervised nets. HED automatically learns rich hierarchical representations (guided by deep supervision on side responses) that are important in order to resolve the challenging ambiguity in edge and object boundary detection. We significantly advance the state-of-the-art on the BSDS500 dataset (ODS F-score of 0.790) and the NYU Depth dataset (ODS F-score of 0.746), and do so with an improved speed (0.4 s per image) that is orders of magnitude faster than some CNN-based edge detection algorithms developed before HED. We also observe encouraging results on other boundary detection benchmark datasets such as Multicue and PASCAL-Context. © 2017 Springer Science+Business Media New York
Volkmann T.,9500 Gilman Drive |
Lozada R.,Patronato Pro COMUSIDA |
Anderson C.M.,9500 Gilman Drive |
Patterson T.L.,9500 Gilman Drive |
And 2 more authors.
Harm Reduction Journal | Year: 2011
Objective: To assess factors associated with drug-related harms related to policing among injection drug users (IDUs) in Tijuana, Mexico.Methods: IDUs who were over 18 years old and had injected drugs within the last six months were recruited via respondent-driven sampling and underwent questionnaires and testing for HIV (human immunodeficiency virus), syphilis and TB (tuberculosis). Random effects logistic regression was used to simultaneously model factors associated with five drug-related harms related to policing practices in the prior six months (i.e., police led them to rush injections; affected where they bought drugs; affected locations where they used drugs; feared that police will interfere with their drug use; receptive syringe sharing).Results: Of 727 IDUs, 85% were male; median age was 38 years. Within the last 6 months, 231 (32%) of IDUs reported that police had led them to rush injections, affected where they bought or used drugs or were very afraid police would interfere with their drug use, or shared syringes. Factors independently associated with drug-related harms related to policing within the last six months included: recent arrest, homelessness, higher frequencies of drug injection, use of methamphetamine, using the local needle exchange program and perceiving a decrease in the purity of at least one drug.Conclusions: IDUs who experienced drug-related harms related to policing were those who were most affected by other micro and macro influences in the physical risk environment. Police education programs are needed to ensure that policing practices do not exacerbate risky behaviors or discourage protective behaviors such as needle exchange program use, which undermines the right to health for people who inject drugs. © 2011 Volkmann et al; licensee BioMed Central Ltd.
Hur G.H.,9500 Gilman Drive |
Vickery C.R.,9500 Gilman Drive |
Burkart M.D.,9500 Gilman Drive
Natural Product Reports | Year: 2012
Covering up to the end of 2011 Many pharmaceuticals on the market today belong to a large class of natural products called nonribosomal peptides (NRPs). Originating from bacteria and fungi, these peptide-based natural products consist not only of the 20 canonical l-amino acids, but also non-proteinogenic amino acids, heterocyclic rings, sugars, and fatty acids, generating tremendous chemical diversity. As a result, these secondary metabolites exhibit a broad array of bioactivity, ranging from antimicrobial to anticancer. The biosynthesis of these complex compounds is carried out by large multimodular megaenzymes called nonribosomal peptide synthetases (NRPSs). Each module is responsible for incorporation of a monomeric unit into the natural product peptide and is composed of individual domains that perform different catalytic reactions. Biochemical and bioinformatic investigations of these enzymes have uncovered the key principles of NRP synthesis, expanding the pharmaceutical potential of their enzymatic processes. Progress has been made in the manipulation of this biosynthetic machinery to develop new chemoenzymatic approaches for synthesizing novel pharmaceutical agents with increased potency. This review focuses on the recent discoveries and breakthroughs in the structural elucidation, molecular mechanism, and chemical biology underlying the discrete domains within NRPSs. This journal is © The Royal Society of Chemistry 2012.
Wang X.,9500 Gilman Drive |
Duggan B.M.,University of California at San Diego |
Molinski T.F.,9500 Gilman Drive |
Molinski T.F.,University of California at San Diego
Journal of the American Chemical Society | Year: 2015
Four new chlorobromohydrins, mollenynes B-E, were isolated from the marine sponge Spirastrella mollis collected from Hogsty Reef, Bahamas. Their structures were elucidated by integrated analysis of NMR, MS, and computational methods. A high-resolution band-selective HSQC experiment was developed to identify 13C NMR signals in samples at the nanomole-scale that arise from Cl-substituted 13C by exploiting the 35Cl/37Cl isotope shift. © 2015 American Chemical Society.