234 research outputs found
Many New Hampshire Jobs Do Not Pay a Livable Wage
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
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
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
This is a continuation of the papers [4] of Bleher and Fokin and [5] of
Bleher and Liechty, in which the large asymptotics is obtained for the
partition function 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 asymptotics of 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
<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
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 H in AU Mic
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 23 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 H line profiles and the response of the H lines to a
stellar flare, the H 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 (3650 K) and the
predicted temperature of its star spots (2650 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
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
-enumerated (with ) large alternating sign matrices. In
particular, as 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
We obtain the large asymptotics of the partition function 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 ,
Z_n=C\th_4(n\om) F^{n^2}[1+O(n^{-1})], where \om and are given by
explicit expressions in \ga and , and is the Jacobi theta
function. The proof is based on the Riemann-Hilbert approach to the large
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
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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