1,921 research outputs found
Oviposition Decisions by Indianmeal Moth
The Indianmeal moth, Plodia interpunctella,is a pest in the United States of stored grains. The larvae feed on grains, grain products, dried fruits, nuts, cereals and a variety of processed food products. Indianmeal moths can detect where other Indianmeal moths have laid eggs but it is unknown if they know where other species have been and laid eggs. So, does the colonization of flour by other species affect where an Indianmeal moth will lay her eggs? Our results showed there was no preference for colonized or uncolonized flour by the moths. The average number of eggs laid in both patches of flour was even. This data shows us that the moths do not have a preference where they lay their eggs, potentially increasing competition among species in food patches
Regional variation in histopathologyâspecific incidence of invasive cervical cancer among Peruvian women
ObjectiveTo evaluate patterns of cervical cancer incidence in Peru by examining variation in 2 common histopathologic types, squamous cell carcinoma (SCC) and adenocarcinoma (ADC), and analyzing trends over time.MethodsData on the incidence of invasive cervical cancer between 1984 and 2006 were obtained from 3 populationâbased cancer registries in Peru: Lima, Trujillo, and Arequipa. For each registry, data quality assessment was performed, crude and ageâspecific incidence was calculated, and time trends were analyzed.ResultsOverall and SCC incidence varied across registries but incidence of ADC did not. Overall and SCC incidence showed significant declines in Trujillo (P 0.05) over time. ADC incidence showed marginally significant increases among women aged 15â29 years in Trujillo (P = 0.10) and modest increases among young women in Lima (P > 0.05).ConclusionPopulationâbased cancer registries were an efficient source of data for evaluating the incidence of cervical cancer once data quality had been established. Geographic and temporal variations in cervical cancer burden were documented in Peru. The trends suggest that cervical ADC is increasing among young women in urban Peru, particularly in Trujillo. We recommend supplementing current Papanicolaou test screening with complementary methods of cervical cancer control, including human papillomavirus (HPV) vaccination and HPV DNA testing.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135622/1/ijgo47.pd
Quantum Films Adsorbed on Graphite: Third and Fourth Helium Layers
Using a path-integral Monte Carlo method for simulating superfluid quantum
films, we investigate helium layers adsorbed on a substrate consisting of
graphite plus two solid helium layers. Our results for the promotion densities
and the dependence of the superfluid density on coverage are in agreement with
experiment. We can also explain certain features of the measured heat capacity
as a function of temperature and coverage.Comment: 13 pages in the Phys. Rev. two-column format, 16 Figure
Magnetization creep and decay in YBa2Cu3O7âx thin films with artificial nanostructure pinning
Critical current and flux pinning have been studied for YBa_2Cu_3O_7âx thin films with Y_2BaCuO_5 (211) precipitates introduced as layers and as random distributions. The 211 precipitates were introduced during pulsed laser deposition. In the case of the layered sample, the strata were spaced approximately 6.5 nm apart throughout the film thickness. Magnetically determined critical current density (J_c) was then fitted to J_câB^âα above a magnetic field B*, below which a relatively field independent J_c-self-field was observed, consistent with previous results. Values of α were suppressed from the control sample values of α=0.5 to lower values for pinned samples, reaching α=0.2 for the layer pinned 211 sample at low temperatures. M-H was then measured as a function of ramp rate, and U(J) vs J curves were extracted for temperatures from 4.2 to 77 K for pinned and control samples. Direct magnetization decay measurements were made for the 211 layer pinned sample, and good agreement was seen with ramp-rate-derived results. Using U(J)=(U_0âÎŒ)[(J_câJ)^ÎŒâ1]B^âÎœ, values of ÎŒâ
0.6â0.8 were seen for all samples, while Îœâ
0.4 for control samples, 0.1 for layer pinned samples, and 0.2â0.4 for the random pinned samples. The activation energy scale U_0 was 600â700 and 400 K for layer pinned and control samples, respectively, and 400â500 K for the random pinned samples. The values of ÎŒ and Îœ extracted were inconsistent with two dimensional pinning behavior in all cases, even though the layer spacing in the layer pinned sample is smaller than the calculated collective correlation length. While the layer pinned sample is clearly in the collective pinning regime, the artificial defects in the random pinned sample may be in the isolated strong pinning regime
Development of a CHO production medium utilizing proteomic and metabolomics analysis
productivity. Metabolomics and proteomic analysis was conducted on two medium formulations with disparate growth and production characteristics. Medium formulation 1 (M1) demonstrates moderate peak VCD with a high specific productivity (qP) over a 14 day growth performance assay utilizing a recombinant IgG producing CHO-S cell line and DG44 cell line. Medium formulation 2 (M2) demonstrates a high peak VCD with moderate qP under the same conditions and cell line. A comparative analysis of metabolite abundance and enzyme regulation identified that M1 had greater flux in the sorbitol pathway verses glycolysis, the TCA cycle was upregulated to a greater degree than M2. A Design of Experiment (DoE) study was developed to increase the specific productivity of M1 without decreasing the VCD to M2 levels resulting in a superior volumetric titer. Simultaneously, we utilized traditional empirical approaches to increase the qP of M2 in a parallel set of experiments. We describe here the path to develop the medium, metabolic and proteomic pathways which were found to be important, and a comparison of results based on the traditional empirical path verses the hypothesis based advanced cellular analytics path
Characterization of a Si(Li) Compton polarimeter for the hard x-ray regime, using synchrotron radiation.
BACKGROUND: Buruli ulcer (BU), caused by Mycobacterium ulcerans (M. ulcerans), is a necrotizing skin disease found in more than 30 countries worldwide. BU incidence is highest in West Africa; however, cases have substantially increased in coastal regions of southern Australia over the past 30 years. Although the mode of transmission remains uncertain, the spatial pattern of BU emergence in recent years seems to suggest that there is an environmental niche for M. ulcerans and BU prevalence. METHODOLOGY/PRINCIPAL FINDINGS: Network analysis was applied to BU cases in Victoria, Australia, from 1981-2008. Results revealed a non-random spatio-temporal pattern at the regional scale as well as a stable and efficient BU disease network, indicating that deterministic factors influence the occurrence of this disease. Monthly BU incidence reported by locality was analyzed with landscape and climate data using a multilevel Poisson regression approach. The results suggest the highest BU risk areas occur at low elevations with forested land cover, similar to previous studies of BU risk in West Africa. Additionally, climate conditions as far as 1.5 years in advance appear to impact disease incidence. Warmer and wetter conditions 18-19 months prior to case emergence, followed by a dry period approximately 5 months prior to case emergence seem to favor the occurrence of BU. CONCLUSIONS/SIGNIFICANCE: The BU network structure in Victoria, Australia, suggests external environmental factors favor M. ulcerans transmission and, therefore, BU incidence. A unique combination of environmental conditions, including land cover type, temperature and a wet-dry sequence, may produce habitat characteristics that support M. ulcerans transmission and BU prevalence. These findings imply that future BU research efforts on transmission mechanisms should focus on potential vectors/reservoirs found in those environmental niches. Further, this study is the first to quantitatively estimate environmental lag times associated with BU outbreaks, providing insights for future transmission investigations
The Effects of Distraction and a Brief Intervention on Auditory and Visual-Spatial Working Memory in College Students with Attention Deficit Hyperactivity Disorder
Two studies addressed how young adult college students with attention deficit hyperactivity disorder (ADHD) (n = 44) compare to their nonaffected peers (n = 42) on tests of auditory and visualâspatial working memory (WM), are vulnerable to auditory and visual distractions, and are affected by a simple intervention. Students with ADHD demonstrated worse auditory WM than did controls. A near significant trend indicated that auditory distractions interfered with the visual WM of both groups and that, whereas controls were also vulnerable to visual distractions, visual distractions improved visualWM in the ADHD group. The intervention was ineffective. Limited correlations emerged between self-reported ADHD symptoms and objective test performances; students with ADHD who perceived themselves as more symptomatic often had better WM and were less vulnerable to distractions than their ADHD peers
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