69 research outputs found
The place of the popular element in art music
Thesis (B.M.)--University of Illinois, 1915.Typescript.Incluldes bibliographical references (leaf [17])
Anterior Talofibular Ligament and Superior Extensor Ankle Retinaculum Thicknesses: Relationship with Balance
Purpose
This study determined if anterior talofibular ligament (ATFL)/superior extensor ankle retinaculum (SEAR) thicknesses are related to dynamic balance in individuals with chronic ankle instability (CAI).
Materials and Methods
The subjects were 14 males and 15 females (age=24.52±3.46 years). Ankle instability was assessed using the Cumberland Ankle Instability Tool (CAIT) with a cut off score of 25 to define two groups. SonoSite MTurbo (Fugifilm Sonosite, Inc.) musculoskeletal ultrasound (MSKUS) unit was used to assess ATFL and SEAR thicknesses. Dynamic balance was measured with the Y Balance Test (YBT) and two NeuroCom balance tests.
Results
There were no significant differences in the average ATFL thickness between stable and unstable ankles in those subjects with CAI (0.25±0.03 cm and 0.21±0.05 cm, respectively) or in the SEAR thickness (0.09±0.04 cm and 0.10±0.03 cm, respectively). There were also no significant differences in the right and left ATFL thicknesses (0.23±0.07 cm and 0.21±0.04 cm, respectively) or the SEAR thicknesses (0.09±0.01 cm and 0.09±0.01 cm, respectively) in those without CAI. There were no differences between limbs in composite scores on YBT in those with CAI (p=0.35) and those without CAI (p=0.33). There was a moderate correlation between the left SEAR thickness and the large forward/backward perturbations on the NeuroCom (Natus) motor control test (r=0.51, p=0.006 and r=0.54, p=0.003, respectively).
Conclusion
There were no differences in the ATFL/SEAR thicknesses or balance measures between or within the groups, likely because CAI is multi-factorial and related to mechanisms other than tissue changes alone. More sensitive technology and a better definition of the measurement process may provide more definitive results
Determining Environmental Flow Regime in the Pee Dee Watershed, SC
2010 South Carolina Water Resource Conference. Informing strategic water planning to address natural resource, community and economic challenges
Perception versus reality: A National Cohort Analysis of the surgery-first approach for resectable pancreatic cancer
INTRODUCTION: Although surgical resection is necessary, it is not sufficient for long-term survival in pancreatic ductal adenocarcinoma (PDAC). We sought to evaluate survival after up-front surgery (UFS) in anatomically resectable PDAC in the context of three critical factors: (A) margin status; (B) CA19-9; and (C) receipt of adjuvant chemotherapy.
METHODS: The National Cancer Data Base (2010-2015) was reviewed for clinically resectable (stage 0/I/II) PDAC patients. Surgical margins, pre-operative CA19-9, and receipt of adjuvant chemotherapy were evaluated. Patient overall survival was stratified based on these factors and their respective combinations. Outcomes after UFS were compared to equivalently staged patients after neoadjuvant chemotherapy on an intention-to-treat (ITT) basis.
RESULTS: Twelve thousand and eighty-nine patients were included (n = 9197 UFS, n = 2892 ITT neoadjuvant). In the UFS cohort, only 20.4% had all three factors (median OS = 31.2 months). Nearly 1/3rd (32.7%) of UFS patients had none or only one factor with concomitant worst survival (median OS = 14.7 months). Survival after UFS decreased with each failing factor (two factors: 23 months, one factor: 15.5 months, no factors: 7.9 months) and this persisted after adjustment. Overall survival was superior in the ITT-neoadjuvant cohort (27.9 vs. 22 months) to UFS.
CONCLUSION: Despite the perceived benefit of UFS, only 1-in-5 UFS patients actually realize maximal survival when known factors highly associated with outcomes are assessed. Patients are proportionally more likely to do worst, rather than best after UFS treatment. Similarly staged patients undergoing ITT-neoadjuvant therapy achieve survival superior to the majority of UFS patients. Patients and providers should be aware of the false perception of \u27optimal\u27 survival benefit with UFS in anatomically resectable PDAC
Cosmological parameter estimation using Very Small Array data out to l=1500
We estimate cosmological parameters using data obtained by the Very Small
Array (VSA) in its extended configuration, in conjunction with a variety of
other CMB data and external priors. Within the flat CDM model, we find
that the inclusion of high resolution data from the VSA modifies the limits on
the cosmological parameters as compared to those suggested by WMAP alone, while
still remaining compatible with their estimates. We find that , , , , and
for WMAP and VSA when no external prior is
included.On extending the model to include a running spectral index of density
fluctuations, we find that the inclusion of VSA data leads to a negative
running at a level of more than 95% confidence (),
something which is not significantly changed by the inclusion of a stringent
prior on the Hubble constant. Inclusion of prior information from the 2dF
galaxy redshift survey reduces the significance of the result by constraining
the value of . We discuss the veracity of this result in the
context of various systematic effects and also a broken spectral index model.
We also constrain the fraction of neutrinos and find that at
95% confidence which corresponds to when all neutrino
masses are the equal. Finally, we consider the global best fit within a general
cosmological model with 12 parameters and find consistency with other analyses
available in the literature. The evidence for is only marginal
within this model
High sensitivity measurements of the CMB power spectrum with the extended Very Small Array
We present deep Ka-band ( GHz) observations of the CMB made
with the extended Very Small Array (VSA). This configuration produces a
naturally weighted synthesized FWHM beamwidth of arcmin which covers
an -range of 300 to 1500. On these scales, foreground extragalactic
sources can be a major source of contamination to the CMB anisotropy. This
problem has been alleviated by identifying sources at 15 GHz with the Ryle
Telescope and then monitoring these sources at 33 GHz using a single baseline
interferometer co-located with the VSA. Sources with flux densities \gtsim 20
mJy at 33 GHz are subtracted from the data. In addition, we calculate a
statistical correction for the small residual contribution from weaker sources
that are below the detection limit of the survey.
The CMB power spectrum corrected for Galactic foregrounds and extragalactic
point sources is presented. A total -range of 150-1500 is achieved by
combining the complete extended array data with earlier VSA data in a compact
configuration. Our resolution of allows the first 3
acoustic peaks to be clearly delineated. The is achieved by using mosaiced
observations in 7 regions covering a total area of 82 sq. degrees. There is
good agreement with WMAP data up to where WMAP data run out of
resolution. For higher -values out to , the agreement in
power spectrum amplitudes with other experiments is also very good despite
differences in frequency and observing technique.Comment: 16 pages. Accepted in MNRAS (minor revisions
Determinants of the urinary and serum metabolome in children from six European populations
Background Environment and diet in early life can affect development and health throughout the life course. Metabolic phenotyping of urine and serum represents a complementary systems-wide approach to elucidate environment–health interactions. However, large-scale metabolome studies in children combining analyses of these biological fluids are lacking. Here, we sought to characterise the major determinants of the child metabolome and to define metabolite associations with age, sex, BMI and dietary habits in European children, by exploiting a unique biobank established as part of the Human Early-Life Exposome project (http://www.projecthelix.eu). Methods Metabolic phenotypes of matched urine and serum samples from 1192 children (aged 6–11) recruited from birth cohorts in six European countries were measured using high-throughput 1H nuclear magnetic resonance (NMR) spectroscopy and a targeted LC-MS/MS metabolomic assay (Biocrates AbsoluteIDQ p180 kit). Results We identified both urinary and serum creatinine to be positively associated with age. Metabolic associations to BMI z-score included a novel association with urinary 4-deoxyerythronic acid in addition to valine, serum carnitine, short-chain acylcarnitines (C3, C5), glutamate, BCAAs, lysophosphatidylcholines (lysoPC a C14:0, lysoPC a C16:1, lysoPC a C18:1, lysoPC a C18:2) and sphingolipids (SM C16:0, SM C16:1, SM C18:1). Dietary-metabolite associations included urinary creatine and serum phosphatidylcholines (4) with meat intake, serum phosphatidylcholines (12) with fish, urinary hippurate with vegetables, and urinary proline betaine and hippurate with fruit intake. Population-specific variance (age, sex, BMI, ethnicity, dietary and country of origin) was better captured in the serum than in the urine profile; these factors explained a median of 9.0% variance amongst serum metabolites versus a median of 5.1% amongst urinary metabolites. Metabolic pathway correlations were identified, and concentrations of corresponding metabolites were significantly correlated (r > 0.18) between urine and serum. Conclusions We have established a pan-European reference metabolome for urine and serum of healthy children and gathered critical resources not previously available for future investigations into the influence of the metabolome on child health. The six European cohort populations studied share common metabolic associations with age, sex, BMI z-score and main dietary habits. Furthermore, we have identified a novel metabolic association between threonine catabolism and BMI of children
Methods for Effectively Combining Group- and Individual-Level Data
In observational studies researchers often have access to multiple sources of information but ultimately choose to apply well-established statistical methods that do not take advantage of the full range of information available. In this dissertation I discuss three methods that are able to incorporate this additional data and show how using each improves the quality of the analysis.
First, in Chapters 1 and 2, I focus on methods for improving estimator efficiency in studies in which both population (group) and individual-level data is available. In such settings, the hybrid design for ecological inference efficiently combines the two sources of information; however, in practice, maximizing the likelihood is often computationally intractable. I propose and develop an alternative, computationally efficient representation of the hybrid likelihood. I then demonstrate that this approximation incurs no penalty in terms of increased bias or reduced efficiency.
Second, in Chapters 3 and 4, I highlight the problem of applying standard analyses to outcome-dependent sampling schemes in settings in which study units are cluster-correlated. I demonstrate that incorporating known outcome totals into the likelihood via inverse probability weights results in valid estimation and inference. I further discuss the applicability of outcome-dependent sampling schemes in resource-limited settings, specifically to the analysis of national ART programs in sub-Saharan Africa. I propose the cluster-stratified case-control study as a valid and logistically reasonable study design in such resource-poor settings, discuss balanced versus unbalanced sampling techniques, and address the practical trade-off between logistic considerations and statistical efficiency of cluster-stratified case-control versus case-control studies.
Finally, in Chapter 5, I demonstrate the benefit of incorporating the full-range of possible outcomes into an observational data analysis, as opposed to running the analysis on a pre-selected set of outcomes. Testing all possible outcomes for associations with the exposure inherently incorporates negative controls into the analysis and further validates a study's statistically significant results. I apply this technique to an investigation of the relationship between particulate air pollution and hospital admission causes.Biostatistic
The role of notch signaling in vessel maturation and stabilization
Vascular development and angiogenesis initially depend on endothelial tip cell invasion, which is followed by a series of maturation steps, including lumen formation and recruitment of perivascular cells. Many studies have shown that Notch signaling is involved throughout embryonic vascular development, including the regulation of tip cell formation, artery/vein patterning, and vascular remodeling. However, the role of Notch signaling in the postnatal vasculature has not been well described. Blocking postnatal Notch results in a highly branched, immature vascular plexus. Vascular plexus maturation is partly regulated by vascular smooth muscle cell (VSMC) coverage, and little is known about the role of Notch in the postnatal perivascular compartment. Therefore, the studies in this dissertation proposed to investigate Notch effectors in VSMCs that modulate vessel maturation during postnatal angiogenesis. To verify that Notch signaling is important for postnatal arterial VSMC coverage and subsequent vessel maturation, the perivascular compartment of pups undergoing retinal angiogenesis was examined following Notch inhibition. This resulted in significantly less arterial VSMC coverage. An angiogenesis-specific microarray panel identified Notch effector genes upregulated in VSMCs in contact with the endothelial Notch ligand Jagged1, which is known to be required for arterial VSMC coverage. One of the upregulated genes was integrin [beta]3, which led to increased surface expression of the integrin heterodimer, [alpha]v[beta]3. Integrin [alpha]v[beta]3 is important for cell adhesion and cell migration. In the vasculature, the only available ligand for [alpha]v[beta]3 is von Willebrand Factor (vWF). Examination of pups undergoing retinal developmental angiogenesis revealed that VSMC coverage co-patterns with accumulation of vWF in the endothelial basement membrane. In a 3-dimensional in vitro tube formation assay, disruption of Notch, [alpha]v[beta]3, or vWF prevented an association between VSMCs and newly formed endothelial tubes. Genetic or pharmacological disruption of Jagged1, [alphav]v[beta]3, or vWF suppressed VSMC coverage of nascent vessels and arterial maturation during vascular development in vivo. Therefore, the findings described in this dissertation define a Notch-mediated interaction between the developing endothelium and VSMCs, leading to adhesion of VSMCs to the endothelial basement membrane and arterial maturatio
- …