1,187 research outputs found
A Case Study of Error in Survey Reports of Move Month Using the U.S. Postal Service Change of Address Records
Correctly recalling where someone lived as of a particular date is critical to the accuracy of the once-a-decade U.S. decennial
census. The data collection period for the 2010 Census occurred over the course of a few months: February to August, with some
evaluation operations occurring up to 7 months after that. The assumption was that respondents could accurately remember moves
and move dates on and around April 1st up to 11 months afterwards. We show how statistical analyses can be used to investigate
the validity of this assumption by comparing self-reports and proxy-reports of the month of a move in a U.S. Census Bureau survey
with an administrative records database from the U.S. Postal Service containing requests to forward mail filed in March and April of
2010. In our dataset, we observed that the length of time since the move affects memory error in reports of a move and the month of
a move. Also affecting memory error of moves is whether the respondent is reporting for themselves or another person in the
household . This case study is relevant to surveys as well as censuses because move dates and places of residence often serve as
anchors to aid memory of other events in questionnaires
Recruitment of Dental Hygiene Students from Underrepresented Minority Groups: A National Survey of U.S. Dental Hygiene Programs
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153698/1/jddj0022033720157910tb06010x.pd
Interactive effects of prey and p,p′-DDE on Burrowing Owl population dynamics
Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecological Applications 16 (2006): 666–677.We used population models to explore the effects of the organochlorine contaminant
p,p'DDE and fluctuations in vole availability on the population dynamics of Burrowing
Owls (Athene cunicularia). Previous work indicated an interaction between low biomass of voles in the diet and moderate levels of p,p'DDE in Burrowing Owl eggs that led to reproductive impairment. We constructed periodic and stochastic matrix models that incorporated three vole population states observed in the field: average, peak and crash years. We modeled varying frequencies of vole crash years and a range of impairment of owl demographic rates in vole crash years. Vole availability had a greater impact on owl population growth rate than reproductive impairment if vole populations peaked and crashed frequently. However, this difference disappeared as the frequency of vole crash years declined to once per decade. Fecundity,
the demographic rate most affected by p,p'DDE, had less impact on population growth rate
than adult or juvenile survival. A life table response experiment of time-invariant matrices for
average, peak and crash vole conditions showed that low population growth under vole crash
conditions was due to low adult and juvenile survival rates, whereas the extremely high population growth under vole peak conditions was due to increased fecundity. Our results suggest
that even simple models can provide useful insights into complex ecological interactions. This is
particularly valuable when temporal or spatial scales preclude manipulative experimental work
in the field or laboratory.Field work was supported by grants from the U.S. Navy EFA West, California Department of Fish and Game,
and the National Fish and Wildlife Foundation to D. K. Rosenberg. Analysis was supported
in part by the U.S. Environmental Protection Agency (R-82908901-0)
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Concomitant medication use and clinical outcome of repetitive Transcranial Magnetic Stimulation (rTMS) treatment of Major Depressive Disorder.
BackgroundRepetitive Transcranial Magnetic Stimulation (rTMS) is commonly administered to Major Depressive Disorder (MDD) patients taking psychotropic medications, yet the effects on treatment outcomes remain unknown. We explored how concomitant medication use relates to clinical response to a standard course of rTMS.MethodsMedications were tabulated for 181 MDD patients who underwent a six-week rTMS treatment course. All patients received 10 Hz rTMS administered to left dorsolateral prefrontal cortex (DLPFC), with 1 Hz administered to right DLPFC in patients with inadequate response to and/or intolerance of left-sided stimulation. Primary outcomes were change in Inventory of Depressive Symptomatology Self Report (IDS-SR30) total score after 2, 4, and 6 weeks.ResultsUse of benzodiazepines was associated with less improvement at week 2, whereas use of psychostimulants was associated with greater improvement at week 2 and across 6 weeks. These effects were significant controlling for baseline variables including age, overall symptom severity, and severity of anxiety symptoms. Response rates at week 6 were lower in benzodiazepine users versus non-users (16.4% vs. 35.5%, p = 0.008), and higher in psychostimulant users versus non-users (39.2% vs. 22.0%, p = 0.02).ConclusionsConcomitant medication use may impact rTMS treatment outcome. While the differences reported here could be considered clinically significant, results were not corrected for multiple comparisons and findings should be replicated before clinicians incorporate the evidence into clinical practice. Prospective, hypothesis-based treatment studies will aid in determining causal relationships between medication treatments and outcome
Alveolar macrophages lack CCR2 expression and do not migrate to CCL2
Background: The recruitment of mononuclear cells has important implications for tissue
inflammation. Previous studies demonstrated enhanced CCR1 and CCR5 expression and
decreased CCR2 expression during in vitro monocyte to macrophage differentiation. To date, no
study examined the in vivo differences in chemokine receptor expression between human
peripheral blood monocytes and alveolar macrophages.
Methods: We examined the expression of these receptors in human peripheral blood monocytes
and alveolar macrophages using microarray analysis, reverse-transcriptase PCR, flow cytometry
and migration analyses.
Results: In contrast to peripheral blood monocytes, alveolar macrophages did not express the
CCL2 receptor, CCR2, and did not migrate toward CCL2. In contrast, monocytes and freshly
isolated resident alveolar macrophages both migrated towards CCL3. However, up to 6-fold more
monocytes migrated toward equivalent concentrations of CCL3 than did alveolar macrophages
from the same donor. While peripheral blood monocytes expressed the CCL3 receptor, CCR1,
alveolar macrophages expressed the alternate CCL3 receptor, CCR5. The addition of anti-CCR5
blocking antibodies completely abrogated CCL3-induced migration in alveolar macrophages, but
did not affect the migration of peripheral blood monocytes.
Conclusion: These data support the specificity of CCL2 to selectively drive monocyte, but not
alveolar macrophage recruitment to the lung and CCR5 as the primary macrophage receptor for
CCL3
Effects of Dietary Sodium Intake on Blood Flow Regulation During Exercise in Salt Resistant Individuals
PURPOSE: Dietary sodium intake guidelines is ≤2,300 mg/day, yet is exceeded by 90% of Americans. This study examined the impact of a high sodium diet on blood flow regulation during exercise. METHODS: Six males (25 ± 2 years) consumed dietary sodium intake guidelines for two weeks, with one week salt-capsule supplemented (HS: 6,900 mg/day of sodium) and the other week placebo-capsule supplemented (LS: 2,300 mg/day of sodium). At the end of each week, peripheral hemodynamic measurements [blood flow (BF), shear rate (SR), and flow mediated dilation (FMD)/SR)] of the brachial and superficial femoral artery were taken during handgrip (HG) and plantar flexion (PF) exercise, respectively. Each exercise workload was 3 minutes and progressed by 8 kilograms until exhaustion. RESULTS: There were no differences between LS and HS in blood pressure (82 ± 4 v 80 ± 5 mmHg; p = 0.3) or heart rate (56 ± 6 v 59 ± 10 bpm; p = 0.4). HG and PF exercise increased BF, SR, and FMD/SR across workload (p \u3c 0.03 for all), but no difference between diets (p \u3e 0.05 for all). CONCLUSION: Despite previous reports that HS impairs resting vascular function, this study revealed that peripheral vascular function and blood flow regulation during exercise is not impacted by a HS diet.https://scholarscompass.vcu.edu/gradposters/1082/thumbnail.jp
Kinetochore alignment within the metaphase plate is regulated by centromere stiffness and microtubule depolymerases
During mitosis in most eukaryotic cells, chromosomes align and form a metaphase plate halfway between the spindle poles, about which they exhibit oscillatory movement. These movements are accompanied by changes in the distance between sister kinetochores, commonly referred to as breathing. We developed a live cell imaging assay combined with computational image analysis to quantify the properties and dynamics of sister kinetochores in three dimensions. We show that baseline oscillation and breathing speeds in late prometaphase and metaphase are set by microtubule depolymerases, whereas oscillation and breathing periods depend on the stiffness of the mechanical linkage between sisters. Metaphase plates become thinner as cells progress toward anaphase as a result of reduced oscillation speed at a relatively constant oscillation period. The progressive slowdown of oscillation speed and its coupling to plate thickness depend nonlinearly on the stiffness of the mechanical linkage between sisters. We propose that metaphase plate formation and thinning require tight control of the state of the mechanical linkage between sisters mediated by centromeric chromatin and cohesion
Dynamic changes in 5-hydroxymethylation signatures underpin early and late events in drug exposed liver
Aberrant DNA methylation is a common feature of neoplastic lesions, and early detection of such changes may provide powerful mechanistic insights and biomarkers for carcinogenesis. Here, we investigate dynamic changes in the mouse liver DNA methylome associated with short (1 day) and prolonged (7, 28 and 91 days) exposure to the rodent liver non-genotoxic carcinogen, phenobarbital (PB). We find that the distribution of 5mC/5hmC is highly consistent between untreated individuals of a similar age; yet, changes during liver maturation in a transcriptionally dependent manner. Following drug treatment, we identify and validate a series of differentially methylated or hydroxymethylated regions: exposure results in staged transcriptional responses with distinct kinetic profiles that strongly correlate with promoter proximal region 5hmC levels. Furthermore, reciprocal changes for both 5mC and 5hmC in response to PB suggest that active demethylation may be taking place at each set of these loci via a 5hmC intermediate. Finally, we identify potential early biomarkers for non-genotoxic carcinogenesis, including several genes aberrantly expressed in liver cancer. Our work suggests that 5hmC profiling can be used as an indicator of cell states during organ maturation and drug-induced responses and provides novel epigenetic signatures for non-genotoxic carcinogen exposur
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