Traceability in Food Systems: An Economic Analysis of LGMA and the 2006 Spinach Outbreak

This case study presents an in-depth review of network structures and costs associated with the implementation of traceability systems in California leafy green production, distribution, and retailing. The 2006 spinach outbreak is used to assess the economic impact of trace back/forward response time of the LGMA system, an example of a tightly coupled, linear supply network. Results suggest that the benefits of traceability systems may far outweigh the costs and that costs vary significantly by technology used and by grower size. Implications are derived for cost-effectiveness of rapid response, targeted trace back/forward systems in other types of supply networks.traceability, produce, supply networks, cost-effectiveness, Food Consumption/Nutrition/Food Safety, Production Economics, Q18, I18, L51,

7. The 1970s

From View from the Dean’s Office by Robert McKersie. “I had been on the job just a week when Keith Kennedy, vice provost, called and said we needed to make a trip to Albany to meet the chancellor of SUNY, Ernest Boyer. This was late August 1971. After a few pleasantries, it became clear that this was not just the courtesy call of a new dean reporting in to the top leader of the state university. Chancellor Boyer went right to the point: a new Labor College was going to open on the premises of Local 3 IBEW’s training facility on Lexington Avenue in Manhattan, and the ILR School had to be there as a partner. It was not clear what unit of SUNY would take over the Labor College, but it was clear that given its broad mandate for labor education, the ILR School was going to play a key role.” Includes: View from the Dean’s Office; From Eric Himself; Another Perspective; Labor College Graduation: VanArsdale’s Dream Fulfilled; The View of a Visiting Faculty Member; Another Perspective; and The Student’s View

Book Reviews

CARDOZO AND FRONTIERS OF LEGAL THINKING. By B. H. Levy. Cleveland: Case Western Reserve University Press, 1969. Pp. xi, 365. 9.95. KEEPING THE PEACE. By Herbert Jenkins. New York: Harper & Row, 1970. Pp. 203. 5.95. ATTORNEYS\u27 GUIDE TO SELECTIVE SERVICE AND MILITARY CASE LAW. By Curry First. Philadelphia: Central Committee for Conscientious Objectors, 1969. Pp. 187. $3.50. Supplement, 1970. Pp. 53.$1.75. TRUTH IN REAL ESTATE LENDING. By Joseph L. Abraham. Chicago, Ill., Commerce Clearing House, 1970. Pp. xii, 299. $12.50

Improving In-Stream Nutrient Routines in Water Quality Models Using Stable Isotope Tracers: A Review and Synthesis

Water quality models serve as an economically feasible alternative to quantify fluxes of nutrient pollution and to simulate effective mitigation strategies; however, their applicability is often questioned due to broad uncertainties in model structure and parameterization, leading to uncertain outputs. We argue that reduction of uncertainty is partially achieved by integrating stable isotope data streams within the water quality model architecture. This article outlines the use of stable isotopes as a response variable within water quality models to improve the model boundary conditions associated with nutrient source provenance, constrain model parameterization, and elucidate shortcomings in the model structure. To assist researchers in future modeling efforts, we provide an overview of stable isotope theory; review isotopic signatures and applications for relevant carbon, nitrogen, and phosphorus pools; identify biotic and abiotic processes that impact isotope transfer between pools; review existing models that have incorporated stable isotope signatures; and highlight recommendations based on synthesis of existing knowledge. Broadly, we find existing applications that use isotopes have high efficacy for reducing water quality model uncertainty. We make recommendations toward the future use of sediment stable isotope signatures, given their integrative capacity and practical analytical process. We also detail a method to incorporate stable isotopes into multi-objective modeling frameworks. Finally, we encourage watershed modelers to work closely with isotope geochemists to ensure proper integration of stable isotopes into in-stream nutrient fate and transport routines in water quality models

Bed-Site Selection by Neonatal White-tailed Deer in Central North Dakota

Understanding bed-site selection and vegetation characteristics provides valuable information for population management (Verme 1977, Huegel et al. 1985a, Nelson and Woolf 1987). Predation and other natural-caused mortalities of white-tailed deer (Odocoileus virginianus) neonates are most likely to occur within the first 60 days of life; a time period when selected habitat characteristics are vital to survival (Verme 1977, Huegel et al. 1985a, Nelson and Woolf 1987, Grovenburg et al. 2010). Prior to the study of Grovenburg et al. (2010), limited research had been completed on bed-site selection of neonatal white-tailed deer in the grasslands of the Northern Great Plains. In north-central South Dakota, increase in vertical height of vegetation was the most important habitat characteristic at bed sites, which likely pertained directly to protection from predation and thermal insulation (Grovenburg et al. 2010, 2012a). Our objective was to describe the physical and vegetative characteristics of bed sites selected by neonatal white-tailed deer in the grassland dominated landscape of central North Dakota. We hypothesized that neonatal whitetailed deer would select bed sites characterized by relatively high understory vegetation to moderate ambient temperatures resulting in favorable microclimates for maintaining thermal neutrality while providing concealment from predator

NOTES: BED-SITE SELECTION BY NEONATAL WHITE-TAILED DEER IN CENTRAL NORTH DAKOTA

Understanding bed-site selection and vegetation characteristics provides valuable information for population management (Verme 1977, Huegel et al. 1985a, Nelson and Woolf 1987). Predation and other natural-caused mortalities of white-tailed deer (Odocoileus virginianus) neonates are most likely to occur within the first 60 days of life; a time period when selected habitat characteristics are vital to survival (Verme 1977, Hue- gel et al. 1985a, Nelson and Woolf 1987, Grovenburg et al. 2010). Prior to the study of Grovenburg et al. (2010), limited research had been completed on the bed-site selection of neonatal white-tailed deer in the grasslands of the Northern Great Plains. In north-central South Dakota, increase in vertical height of vegetation was the most important habitat characteristic at bed sites, which likely pertained directly to protection from predation and thermal insulation (Grovenburg et al. 2010, 2012a). Our objective was to describe the physical and vegetative characteristics of bed sites selected by neonatal white-tailed deer in the grassland dominated landscape of central North Dakota. We hypothesized that neonatal white-tailed deer would select bed sites characterized by relatively high understory vegetation to moderate ambient temperatures resulting in favorable microclimates for maintaining thermal neutrality while providing concealment from predators. We studied neonatal white-tailed deer in Burleigh County in central North Dakota, which comprised an area of 2,652 km2. The study area was located within the Northwestern Glaciated Plains level III Ecoregion (Bryce et al. 1998) and was characterized by significant surface irregularity and high concentration of wetlands (United States Department of Agriculture 2011). Long-term (30-year) mean summer temperatures ranged from 13.1° C to 27.5° C and mean (30- year) annual precipitation was 44.9 cm (North Dakota State Climate Office 2012). Nearly all land within the region was used for agricultural purposes. Grasslands and croplands dominated the landscape at 66.2% and 21.0%, respectively. Additionally, wetlands and water comprised 7.4%, developed land 5.2%, and other land uses \u3c1% of the landscape (United States Department of Agriculture 2011). Furthermore, Burleigh County had 4,884 ha in Wildlife Management Areas, 6,844 ha in National Wildlife Refuges, and 4,546 ha in Waterfowl Production Areas (C. Penner, North Dakota Game and Fish Department, personal communication)

Convolutional Embedding of Attributed Molecular Graphs for Physical Property Prediction

The task of learning an expressive molecular representation is central to developing quantitative structure–activity and property relationships. Traditional approaches rely on group additivity rules, empirical measurements or parameters, or generation of thousands of descriptors. In this paper, we employ a convolutional neural network for this embedding task by treating molecules as undirected graphs with attributed nodes and edges. Simple atom and bond attributes are used to construct atom-specific feature vectors that take into account the local chemical environment using different neighborhood radii. By working directly with the full molecular graph, there is a greater opportunity for models to identify important features relevant to a prediction task. Unlike other graph-based approaches, our atom featurization preserves molecule-level spatial information that significantly enhances model performance. Our models learn to identify important features of atom clusters for the prediction of aqueous solubility, octanol solubility, melting point, and toxicity. Extensions and limitations of this strategy are discussed

Three-dimensional Structure of HIV-1 Virus-like Particles by Electron Cryotomography

While the structures of nearly every HIV-1 protein are known in atomic detail from X-ray crystallography and NMR spectroscopy, many questions remain about how the individual proteins are arranged in the mature infectious viral particle. Here, we report the three-dimensional structures of individual HIV-1 virus-like particles (VLPs) as obtained by electron cryotomography. These reconstructions revealed that while the structures and positions of the conical cores within each VLP were unique, they exhibited several surprisingly consistent features, including similarities in the size and shape of the wide end of the capsid (the “base”), uniform positioning of the base and other regions of the capsid 11 nm away from the envelope/MA layer, a cone angle that typically varied from 24° to 18° around the long axis of the cone, and an internal density (presumably part of the NC/RNA complex) cupped within the base. Multiple and nested capsids were observed. These results support the fullerene cone model for the viral capsid, indicate that viral maturation involves a free re-organization of the capsid shell rather than a continuous condensation, imply that capsid assembly is both concentration-driven and template-driven, suggest that specific interactions exist between the capsid and the adjacent envelope/MA and NC/RNA layers, and show that a particular capsid shape is favored strongly in-vivo