3,752 research outputs found
Are the Great Lakes cities becoming service centers?
A look at how the dwindling manufacturing base in the Midwest's 10 major metropolitan areas has transformed them into service centers for their surrounding communities, which have picked up many of the factory jobs that have left the cities.Great Lakes ; Service industries
Human Factors Vehicle Displacement Analysis: Engineering In Motion
While positioned on the launch pad at the Kennedy Space Center, tall stacked launch vehicles are exposed to the natural environment. Varying directional winds and vortex shedding causes the vehicle to sway in an oscillating motion. The Human Factors team recognizes that vehicle sway may hinder ground crew operation, impact the ground system designs, and ultimately affect launch availability . The objective of this study is to physically simulate predicted oscillation envelopes identified by analysis. and conduct a Human Factors Analysis to assess the ability to carry out essential Upper Stage (US) ground operator tasks based on predicted vehicle motion
Common, Weird and Unusual Spots Showing up on Corn
There have been several recent reports of leaf spots showing up on corn in addition to the eyespot and Goss’s wilt reported earlier this growing season. Some of these are expected – Northern corn leaf blight and gray leaf spot, but some such as southern rust are a little less common, and others are just weird
The impact of recent vincristine on human hematopoietic progenitor cell collection in pediatric patients with central nervous system tumors
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108370/1/trf12574.pd
Reconstituted high-density lipoproteins promote wound repair and blood flow recovery in response to ischemia in aged mice
Background: The average population age is increasing and the incidence of age-related vascular complications is rising in parallel. Impaired wound healing and disordered ischemia-mediated angiogenesis are key contributors to age-impaired vascular complications that can lead to amputation. High-density lipoproteins (HDL) have vasculo-protective properties and augment ischemia-driven angiogenesis in young animals. We aimed to determine the effect of reconstituted HDL (rHDL) on aged mice in a murine wound healing model and the hindlimb ischemia (HLI) model. Methods: Murine wound healing model—24-month-old aged mice received topical application of rHDL (50 μg/wound/ day) or PBS (vehicle control) for 10 days following wounding. Murine HLI model—Femoral artery ligation was performed on 24-month-old mice. Mice received rHDL (40 mg/kg) or PBS, intravenously, on alternate days, 1 week pre-surgery and up to 21 days post ligation. For both models, blood flow perfusion was determined using laser Doppler perfusion imaging. Mice were sacrificed at 10 (wound healing) or 21 (HLI) days post-surgery and tissues were collected for histological and gene analyses. Results: Daily topical application of rHDL increased the rate of wound closure by Day 7 post-wounding (25 %, p < 0.05). Wound blood perfusion, a marker of angiogenesis, was elevated in rHDL treated wounds (Days 4–10 by 22–25 %, p < 0. 05). In addition, rHDL increased wound capillary density by 52.6 %. In the HLI model, rHDL infusions augmented blood flow recovery in ischemic limbs (Day 18 by 50 % and Day 21 by 88 %, p < 0.05) and prevented tissue necrosis and toe loss. Assessment of capillary density in ischemic hindlimb sections found a 90 % increase in rHDL infused animals. In vitro studies in fibroblasts isolated from aged mice found that incubation with rHDL was able to significantly increase the key pro-angiogenic mediator vascular endothelial growth factor (VEGF) protein (25 %, p < 0.05). Conclusion: rHDL can promote wound healing and wound angiogenesis, and blood flow recovery in response to ischemia in aged mice. Mechanistically, this is likely to be via an increase in VEGF. This highlights a potential role for HDL in the therapeutic modulation of age-impaired vascular complications
A qualitative study of the allergy testing experiences, views and preferences of adult patients
Background
Patients can be tested for IgE sensitivities with in vivo or in vitro testing, but patients’ experiences of different allergy test modalities have not been studied. The objective of this study was to investigate adult patients’ experiences, views and preferences for allergy testing, exploring skin prick testing and allergen-specific IgE testing.
Methods
A qualitative study of adults attending out-patients for investigation of a suspected allergy. A purposive, convenience sample identified participants and semi-structured interviews were conducted, face to face or by telephone. Interviews were recorded and transcribed verbatim. Thematic content analysis was used to explore patients’ experiences.
Results
23 patients were interviewed. The characteristics of skin prick tests particularly valued were the immediacy and visibility of results, which enabled testing and interpretation to be achieved within a single clinic appointment. In vitro testing offered patients simplicity and procedural speed, necessitating only a single puncture site, and was perceived to be a superior test as it was conducted in a laboratory.
Conclusions
The patient preferred method of allergy testing was skin prick testing rather than in vitro allergen specific IgE testing. However, most patients were accepting of either testing modality because their desire to confirm or exclude an allergic trigger overrode any perceived disadvantages of the test method
Understanding and characterizing nestedness in mutualistic bipartite networks
In this work we present a dynamical model that succesfully describes the
organization of mutualistic ecological systems. The main characteristic of
these systems is the nested structure of the bipartite adjacency matrix
describing their interactions. We introduce a nestedness coefficient, as an
alternative to the Atmar and Patterson temperature, commonly used to measure
the nestedness degree of the network. This coefficient has the advantage of
being based on the robustness of the ecological system and it is not only
describing the ordering of the bipartite matrix but it is also able to tell the
difference, if any, between the degree of organization of each guild.Comment: oral talk in Computer Physics Conference CCP2008, Brazi
Radio Sources in Galaxy Clusters at 28.5 GHz
We present serendipitous detections of radio sources at 28.5 GHz (1 cm),
which resulted from our program to image thermal Sunyaev-Zeldovich (SZ) effect
in 56 galaxy clusters. We find 64 radio sources with fluxes down to 0.4 mJy,
and within 250 arcseconds from the pointing centers. The spectral indices (S ~
\nu^-\alpha) of 54 sources with published low frequency flux densities range
from -0.6 to 2 with a mean of 0.77, and a median of 0.84. Extending low
frequency surveys of radio sources towards galaxy clusters CL 0016+16, Abell
665, and Abell 2218 to 28.5 GHz, and selecting sources with 1.4 GHz flux
density greater than 7 mJy to form an unbiased sample, we find a mean spectral
index of 0.71 and a median of 0.71. We find 4 to 7 times more sources predicted
from a low frequency survey in areas without galaxy clusters. This excess
cannot be accounted for by gravitational lensing of a background radio
population by cluster potentials, indicating most of the detected sources are
associated with galaxy clusters. For the cluster Abell 2218, the presence of
unsubtracted radio sources with 28.5 GHz flux densities less than 0.5 mJy, can
only contribute to temperature fluctuations at a level of 10 to 25 \muK. The
corresponding error due to radio point source contamination in the Hubble
constant derived through a combined analysis of 28.5 GHz SZ images and X-ray
emission observations ranges from 1% to 6%.Comment: 18 pages, 8 figures, to appear in April 1998 issue of A
Analyzing the effects of lactose on calcium absorption in premature infants using HR-ICP-Mass Spectrometry
Abstract only availableWith advances in neonatal care, premature infants are surviving at increasing rates. During the third trimester of pregnancy, the bone mineral content of infants rapidly increases. It is therefore becoming essential to accurately mimic the womb environment to maintain growth and sustain the health of premature infants as if they were in utero. Regulating calcium absorption in premature infants is crucial primarily for bone formation, as 99% of the calcium in the human body is found in the bones and the teeth. The effect of lactose containing formulas on calcium absorption in premature infants has not been well established. Concerns have been noted in the scientific community regarding lactose intolerance especially in premature infants, as lactase, the enzyme responsible for lactose digestion, is most readily detectible during the third trimester of pregnancy. In this study, in conjunction with Dr. Laura Hillman of the University of Missouri Hospital, each infant was fed lactose and maltose formulas during different weeks using a dual tracer method in which two calcium isotopes were administered, 44Ca orally and 46Ca intravenously. Urine samples were collected after 24 hours. Analysis related natural abundances of calcium isotopes to the measured values in the urine. Polyatomic ion interferences were differentiated from the calcium peaks by analyzing the samples at a resolution of 4000. Mathematical corrections for interferences caused by titanium and doubly charged strontium were determined by measuring the specific isotopes 47Ti and 87Sr++ and using known natural abundances of the interfering isotopes to correct each calcium count rate. Mathematical calculations relate the enriched isotope ratio measurements of 44Ca and 46Ca to calcium absorption. Analysis regarding the effect of lactose on calcium absorption is ongoing. Our data precision on the ICP-MS was acceptable with percent relative standard deviations (%RSD) for external precision over the course of a week at 1.4, 2.2, 0.71, and 1.4 for isotope ratios 42Ca: 43Ca, 42Ca: 44Ca, 42Ca: 46Ca, and 42Ca: 48Ca respectively. Daily internal precision (%RSD) values were .37, 1.3, .69, and 1.5. The precision shows the viability of utilizing HR-ICP-MS analysis for calcium isotope ratios.NSF-REU/NIH Program in Radiochemistr
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