234 research outputs found

    Many New Hampshire Jobs Do Not Pay a Livable Wage

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    Two forces are likely to have the greatest impact on the projected availability of livable wage jobs in coming years. The first is the course of the current economic downturn. Table 11 shows the New England Economic Partnership (NEE P) forecast for New Hampshire's unemployment rate from 2008 to 2012. As the table shows, unemployment is projected to increase from 3.7 percent in 2007 to 4.2 percent in 2009, after which it is projected to gradually fall. The latest NEE P forecast predicted a relatively mild economic contraction, which provides some reason for optimism among New Hampshire workers. However, any optimism should be tempered by the fact that the latest forecast was issued before the dramatic stock market decline and at the beginning of the financial crisis.The second major factor impacting the availability of livable wage jobs is the changing composition of New Hampshire's economic base. Between 2000 and 2007, New Hampshire lost 25,400 manufacturing jobs, representing a 25 percent decline in the industry.10 Over the same period, jobs in education, healthcare, retail trade, and leisure and hospitality grew by about the same number of jobs. To the extent New Hampshire continues in this transition from a production-based to a service-based economy, the proportion of livable wage jobs is expected to decline

    On the mass segregation of stars and brown dwarfs in Taurus

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    We use the new minimum spanning tree (MST) method to look for mass segregation in the Taurus association. The method computes the ratio of MST lengths of any chosen subset of objects, including the most massive stars and brown dwarfs, to the MST lengths of random sets of stars and brown dwarfs in the cluster. This mass segregation ratio (Lambda_MSR) enables a quantitative measure of the spatial distribution of high-mass and low-mass stars, and brown dwarfs to be made in Taurus. We find that the most massive stars in Taurus are inversely mass segregated, with Lambda_MSR = 0.70 +/- 0.10 (Lambda_MSR = 1 corresponds to no mass segregation), which differs from the strong mass segregation signatures found in more dense and massive clusters such as Orion. The brown dwarfs in Taurus are not mass segregated, although we find evidence that some low-mass stars are, with an Lambda_MSR = 1.25 +/- 0.15. Finally, we compare our results to previous measures of the spatial distribution of stars and brown dwarfs in Taurus, and briefly discuss their implications.Comment: 10 pages, 8 figures, accepted for publication in MNRA

    Stevens County Food Assessment

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    This report is the culmination of a year-long community food assessment conducted by staff, students, and faculty at the University of Minnesota Morris, and informed by an advisory council made up of key local stakeholders. The main goal of the community food assessment is to describe food security in Stevens County at both community and individual scales. This assessment examines what food is grown in the county, what food is available, where food can be obtained in various forms, accessibility and affordability of food, as well as county residents’ experiences with and thoughts and suggestions about food. Findings summarized below rely on several different types of data, including a household food security survey, a survey of prices and availability at area grocery stores, personal communications and observations, and secondary data (e.g., from the US Census Bureau). More details about data collection and the key findings presented below are available in the full version of this report. Based on the (available and newly collected) data for this community food assessment, it is clear that Stevens County does not fit the definition of community food security because many residents are food insecure, food insecure residents tend to share characteristics of marginalized populations, and little of the food consumed in Stevens County is produced and processed in Stevens County. Challenges with community food security are of course not necessarily uniquely to Stevens County, MN as they are at least in part a product of the way our regional, national, and global food supply chains presently function.https://digitalcommons.morris.umn.edu/cst/1083/thumbnail.jp

    Exact solution of the six-vertex model with domain wall boundary condition. Critical line between ferroelectric and disordered phases

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    This is a continuation of the papers [4] of Bleher and Fokin and [5] of Bleher and Liechty, in which the large nn asymptotics is obtained for the partition function ZnZ_n of the six-vertex model with domain wall boundary conditions in the disordered and ferroelectric phases, respectively. In the present paper we obtain the large nn asymptotics of ZnZ_n on the critical line between these two phases.Comment: 22 pages, 6 figures, to appear in the Journal of Statistical Physic

    Comparison of stainless and mild steel welding fumes in generation of reactive oxygen species

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    <p>Abstract</p> <p>Background</p> <p>Welding fumes consist of a wide range of complex metal oxide particles which can be deposited in all regions of the respiratory tract. The welding aerosol is not homogeneous and is generated mostly from the electrode/wire. Over 390,000 welders were reported in the U.S. in 2008 while over 1 million full-time welders were working worldwide. Many health effects are presently under investigation from exposure to welding fumes. Welding fume pulmonary effects have been associated with bronchitis, metal fume fever, cancer and functional changes in the lung. Our investigation focused on the generation of free radicals and reactive oxygen species from stainless and mild steel welding fumes generated by a gas metal arc robotic welder. An inhalation exposure chamber located at NIOSH was used to collect the welding fume particles.</p> <p>Results</p> <p>Our results show that hydroxyl radicals (<sup>.</sup>OH) were generated from reactions with H<sub>2</sub>O<sub>2 </sub>and after exposure to cells. Catalase reduced the generation of <b><sup>.</sup></b>OH from exposed cells indicating the involvement of H<sub>2</sub>O<sub>2</sub>. The welding fume suspension also showed the ability to cause lipid peroxidation, effect O<sub>2 </sub>consumption, induce H<sub>2</sub>O<sub>2 </sub>generation in cells, and cause DNA damage.</p> <p>Conclusion</p> <p>Increase in oxidative damage observed in the cellular exposures correlated well with <b><sup>.</sup></b>OH generation in size and type of welding fumes, indicating the influence of metal type and transition state on radical production as well as associated damage. Our results demonstrate that both types of welding fumes are able to generate ROS and ROS-related damage over a range of particle sizes; however, the stainless steel fumes consistently showed a significantly higher reactivity and radical generation capacity. The chemical composition of the steel had a significant impact on the ROS generation capacity with the stainless steel containing Cr and Ni causing more damage than the mild steel. Our results suggest that welding fumes may cause acute lung injury. Since type of fume generated, particle size, and elapsed time after generation of the welding exposure are significant factors in radical generation and particle deposition these factors should be considered when developing protective strategies.</p

    Testing the universality of star formation - I. Multiplicity in nearby star-forming regions

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    We have collated multiplicity data for five clusters (Taurus, Chamaeleon I, Ophiuchus, IC348, and the Orion Nebula Cluster). We have applied the same mass ratio (flux ratios of delta K <= 2.5) and primary mass cuts (~0.1-3.0 Msun) to each cluster and therefore have directly comparable binary statistics for all five clusters in the separation range 62-620 au, and for Taurus, Chamaeleon I, and Ophiuchus in the range 18-830 au. We find that the trend of decreasing binary fraction with cluster density is solely due to the high binary fraction of Taurus, the other clusters show no obvious trend over a factor of nearly 20 in density. With N-body simulations we attempt to find a set of initial conditions that are able to reproduce the density, morphology and binary fractions of all five clusters. Only an initially clumpy (fractal) distribution with an initial total binary fraction of 73 per cent (17 per cent in the range 62-620 au) is able to reproduce all of the observations (albeit not very satisfactorily). Therefore, if star formation is universal the initial conditions must be clumpy and with a high (but not 100 per cent) binary fraction. This could suggest that most stars, including M-dwarfs, form in binaries.Comment: Accepted for publication in MNRAS, 19 pages, 22 figure

    The Mysterious Affair of the H2_2 in AU Mic

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    Molecular hydrogen is the most abundant molecule in the Galaxy and plays important roles for planets, their circumstellar environments, and many of their host stars. We have confirmed the presence of molecular hydrogen in the AU Mic system using high-resolution FUV spectra from HST-STIS during both quiescence and a flare. AU Mic is a \sim23 Myr M dwarf which hosts a debris disk and at least two planets. We estimate the temperature of the gas at 1000 to 2000 K, consistent with previous detections. Based on the radial velocities and widths of the H2_2 line profiles and the response of the H2_2 lines to a stellar flare, the H2_2 line emission is likely produced in the star, rather than in the disk or the planet. However, the temperature of this gas is significantly below the temperature of the photosphere (\sim3650 K) and the predicted temperature of its star spots (\gtrsim2650 K). We discuss the possibility of colder star spots or a cold layer in the photosphere of a pre-main sequence M dwarf.Comment: accepted to ApJ, 20 pages, many figure

    The arctic curve of the domain-wall six-vertex model

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    The problem of the form of the `arctic' curve of the six-vertex model with domain wall boundary conditions in its disordered regime is addressed. It is well-known that in the scaling limit the model exhibits phase-separation, with regions of order and disorder sharply separated by a smooth curve, called the arctic curve. To find this curve, we study a multiple integral representation for the emptiness formation probability, a correlation function devised to detect spatial transition from order to disorder. We conjecture that the arctic curve, for arbitrary choice of the vertex weights, can be characterized by the condition of condensation of almost all roots of the corresponding saddle-point equations at the same, known, value. In explicit calculations we restrict to the disordered regime for which we have been able to compute the scaling limit of certain generating function entering the saddle-point equations. The arctic curve is obtained in parametric form and appears to be a non-algebraic curve in general; it turns into an algebraic one in the so-called root-of-unity cases. The arctic curve is also discussed in application to the limit shape of qq-enumerated (with 0<q40<q\leq 4) large alternating sign matrices. In particular, as q0q\to 0 the limit shape tends to a nontrivial limiting curve, given by a relatively simple equation.Comment: 39 pages, 2 figures; minor correction

    Exact solution of the six-vertex model with domain wall boundary conditions. Antiferroelectric phase

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    We obtain the large nn asymptotics of the partition function ZnZ_n of the six-vertex model with domain wall boundary conditions in the antiferroelectric phase region, with the weights a=\sinh(\ga-t), b=\sinh(\ga+t), c=\sinh(2\ga), |t|<\ga. We prove the conjecture of Zinn-Justin, that as nn\to\infty, Z_n=C\th_4(n\om) F^{n^2}[1+O(n^{-1})], where \om and FF are given by explicit expressions in \ga and tt, and th4(z)\th_4(z) is the Jacobi theta function. The proof is based on the Riemann-Hilbert approach to the large nn asymptotic expansion of the underlying discrete orthogonal polynomials and on the Deift-Zhou nonlinear steepest descent method.Comment: 69 pages, 10 figure

    Evaluation of pulmonary and systemic toxicity following lung exposure to graphite nanoplates: a member of the graphene-based nanomaterial family

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    Background: Graphene, a monolayer of carbon, is an engineered nanomaterial (ENM) with physical and chemical properties that may offer application advantages over other carbonaceous ENMs, such as carbon nanotubes (CNT). The goal of this study was to comparatively assess pulmonary and systemic toxicity of graphite nanoplates, a member of the graphene-based nanomaterial family, with respect to nanoplate size. Methods: Three sizes of graphite nanoplates [20 μm lateral (Gr20), 5 μm lateral (Gr5), and \u3c2 \u3eμm lateral (Gr1)] ranging from 8–25 nm in thickness were characterized for difference in surface area, structure,, zeta potential, and agglomeration in dispersion medium, the vehicle for in vivo studies. Mice were exposed by pharyngeal aspiration to these 3 sizes of graphite nanoplates at doses of 4 or 40 μg/mouse, or to carbon black (CB) as a carbonaceous control material. At 4 h, 1 day, 7 days, 1 month, and 2 months post-exposure, bronchoalveolar lavage was performed to collect fluid and cells for analysis of lung injury and inflammation. Particle clearance, histopathology and gene expression in lung tissue were evaluated. In addition, protein levels and gene expression were measured in blood, heart, aorta and liver to assess systemic responses. Results: All Gr samples were found to be similarly composed of two graphite structures and agglomerated to varying degrees in DM in proportion to the lateral dimension. Surface area for Gr1 was approximately 7-fold greater than Gr5 and Gr20, but was less reactive reactive per m2 . At the low dose, none of the Gr materials induced toxicity. At the high dose, Gr20 and Gr5 exposure increased indices of lung inflammation and injury in lavage fluid and tissue gene expression to a greater degree and duration than Gr1 and CB. Gr5 and Gr20 showed no or minimal lung epithelial hypertrophy and hyperplasia, and no development of fibrosis by 2 months post-exposure. In addition, the aorta and liver inflammatory and acute phase genes were transiently elevated in Gr5 and Gr20, relative to Gr1. Conclusions: Pulmonary and systemic toxicity of graphite nanoplates may be dependent on lateral size and/or surface reactivity, with the graphite nanoplates \u3e 5 μm laterally inducing greater toxicity which peaked at the early time points post-exposure relative to the 1–2 μm graphite nanoplate
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