Intramuscular fat and sensory properties of pork loin

Pork loins (n= 53) were selected from a commercial packing plant to determine the influence of subjective visual marbling score on sensory attributes and quality properties. The loins were obtained from commercial hybrid castrated male pigs originating from different herds fed similar commercial diets. Increasing subjective marbling score corresponded with decreased protein content, less percent drip loss, increased pH, and more desirable sensory tenderness and juiciness scores. Greater visual marbling scores resulted in more desirable sensory scores and may be used or included as one of the variables to evaluate fresh pork quality

Post-fire comparisons of forest floor and soil carbon, nitrogen, and mercury pools with fire severity indices

Forest fires are important contributors of C, N, and Hg to the atmosphere. In the fall of 2011, a large wildfire occurred in northern Minnesota and we were able to quickly access the area to sample the forest floor and mineral soil for C, N, and Hg pools. When compared with unburned reference soils, the mean loss of C resulting from fire in the forest floor and the upper 20 cm of mineral soil was 19.3 Mg ha−1, for N the mean loss was 0.17 Mg ha−1, and for Hg the mean loss was 9.3 g ha−1. To assess the influence of fire severity on the forest floor and mineral soils, we used an established method that included a soil burn severity index and a tree burn severity index with a gradient of severity classes. It was apparent that the unburned reference class had greater forest floor C, N, and Hg pools and higher C/N ratios than the burned classes. The C/N ratios of the 0- to 10- and 10- to 20-cm mineral soils in the unburned reference class were also greater than in the burned classes, indicating that a small amount of C was lost and/or N was gained, potentially through leaching unburned forest floor material. However, with a couple of exceptions, the severity classes were unable to differentiate the forest floor and mineral soil impacts among soil burn and tree burn severity indices. Developing burn severity indices that are reflective of soil elemental impacts is an important first step in scaling ecosystem impacts both within and across fire events

US National Climate Assessment (NCA) Scenarios for Assessing Our Climate Future: Issues and Methodological Perspectives Background Whitepaper for Participants

This whitepaper is intended to provide a starting point for discussion at a workshop for the National Climate Assessment (NCA) that focuses on the use and development of scenarios. The paper will provide background needed by participants in the workshop in order to review options for developing and using scenarios in NCA. The paper briefly defines key terms and establishes a conceptual framework for developing consistent scenarios across different end uses and spatial scales. It reviews uses of scenarios in past U.S. national assessments and identifies potential users of and needs for scenarios for both the report scheduled for release in June 2013 and to support an ongoing distributed assessment process in sectors and regions around the country. Because scenarios prepared for the NCA will need to leverage existing research, the paper takes account of recent scientific advances and activities that could provide needed inputs. Finally, it considers potential approaches for providing methods, data, and other tools for assessment participants. We note that the term 'scenarios' has many meanings. An important goal of the whitepaper (and portions of the workshop agenda) is pedagogical (i.e., to compare different meanings and uses of the term and make assessment participants aware of the need to be explicit about types and uses of scenarios). In climate change research, scenarios have been used to establish bounds for future climate conditions and resulting effects on human and natural systems, given a defined level of greenhouse gas emissions. This quasi-predictive use contrasts with the way decision analysts typically use scenarios (i.e., to consider how robust alternative decisions or strategies may be to variation in key aspects of the future that are uncertain). As will be discussed, in climate change research and assessment, scenarios describe a range of aspects of the future, including major driving forces (both human activities and natural processes), changes in climate and related environmental conditions (e.g., sea level), and evolution of societal capability to respond to climate change. This wide range of scenarios is needed because the implications of climate change for the environment and society depend not only on changes in climate themselves, but also on human responses. This degree of breadth introduces and number of challenges for communication and research

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Electroreductive Synthesis of Nickel(0) Complexes

Over the last fifty years, the use of nickel catalysts for facilitating organic transformations has skyrocketed. Ni(0) sources act as useful precatalysts because they can enter a catalytic cycle through ligand exchange, without needing to undergo additional elementary steps. However, most Ni(0) precatalysts are synthesized with stoichiometric aluminum–hydride reductants, pyrophoric reagents that are not atom-economical and must be used at cryogenic temperatures. Here, we demonstrate that Ni(II) salts can be reduced on preparative scale using electrolysis to yield a variety of Ni(0) and Ni(II) complexes that are widely used as precatalysts in organic synthesis, including bis(1,5-cyclooctadiene)nickel(0) [Ni(COD)2]. This method overcomes the reproducibility issues of previously reported methods by standardizing the procedure, such that it can be performed anywhere in a robust manner. It can be easily transitioned to large scale through an electrochemical recirculating flow process. We anticipate that this work will accelerate adoption of preparative electrochemistry for the synthesis of low-valent organometallic complexes in academia and industry

Ni-Electrocatalytic Decarboxylative Arylation to Access Quaternary Centers

There is a pressing need, particularly in the field of drug discovery, for general methods that will enable direct coupling of tertiary alkyl frag-ments to (hetero)aryl halides. Herein a uniquely powerful and simple set of conditions for achieving this transformation with unparalleled generality and chemoselectivity is disclosed. This new protocol is placed in context with other recently reported methods, applied to simplify the routes of known bioactive building blocks molecules, and scaled up in both batch and flow. The role of pyridine additive as well as the mechanism of this reaction are interrogated through Cyclic Voltammetry studies, titration experiments, control reactions with Ni(0) and Ni(II)-complexes, and ligand optimization data. Those studies indicate that the formation of a BINAPNi(0) is minimized and the formation of an active pyridine-stabilized Ni(I) species are sustained during the reaction. Our preliminary mechanistic studies ruled out the involvement of Ni(0) species in this electrochemical cross-coupling, which is mediated by Ni(I) species via a Ni(I)-Ni(II)-Ni(III)-Ni(I) catalytic cycle