1,708 research outputs found
Effects of Pesticide Application on the Growth of Soil Nitrifying Bacteria
This research studied the effects of pesticide application on the growth of soil nitrifying bacteria. Nitrosomonas sp. was isolated from the Soil samples gotten from five different locations within the University of Benin, Benin City and cultured using Winogradsky medium. The bacterial isolate was characterized and identified based on its cultural, morphological and biochemical characteristics. After 4 to 5 days of growth, Nitrosomonas Counts obtained from Winogradsky medium ranged from 4.8×103 to 9.2×103cfu/g. There was an increase in bacteria growth at lower pesticide concentration which began to decrease as the pesticide concentration increased with time. The percentage nitrite accumulation gradually decreased with time, the LC50 values were higher than EC50 values which shows that the bacteria could survive and grow at lower pesticide concentrations but were completely inhibited at higher pesticide concentrations. It is therefore very important to examine pesticides so as to determine its toxicity to soil bacteria before application
Origin of charge density at LaAlO3-on-SrTiO3 hetero-interfaces; possibility of intrinsic doping
As discovered by Ohtomo et al., a large sheet charge density with high
mobility exists at the interface between SrTiO3 and LaAlO3. Based on transport,
spectroscopic and oxygen-annealing experiments, we conclude that extrinsic
defects in the form of oxygen vacancies introduced by the pulsed laser
deposition process used by all researchers to date to make these samples is the
source of the large carrier densities. Annealing experiments show a limiting
carrier density. We also present a model that explains the high mobility based
on carrier redistribution due to an increased dielectric constant.Comment: 14 pages, 3 figures, 1 table; accepted for publication in Phys. Rev.
Lett
Understanding Tourism Dynamics Using GIS and Forecasting Model in Banswara District, Rajasthan, India
Understanding the tourism dynamics of an area involves a rigorous literature review, interviewing the local people and experts, and visiting the sites. This also involves getting acquainted with the transport network of the area to know about the accessibility to the tourism destination, which ultimately helps in preparing a suitable plan for tourism development by creating tourist circuits. Forecasting tourism demand with the help of past data helps put a better picture in front of planners and administration so they can plan more efficiently. Thus, a proper understanding of tourism dynamics requires a holistic vision. The present study tried to understand the tourism dynamics of Banswara district in Rajasthan state, India, by using forecasting techniques and GIS. This twin methodology used in this study highlights the fact that Banswara tourism is at its incipient stage and that there is a substantial prospect of religious, historical, and nature-based tourism in this area. Few of the sites are well connected with the road network, and thus, by taking connectivity into account, tourist circuits are designed
Cotransplantation of Adipose Tissue-Derived Insulin-Secreting Mesenchymal Stem Cells and Hematopoietic Stem Cells: A Novel Therapy for Insulin-Dependent Diabetes Mellitus
Aims. Insulin dependent diabetes mellitus (IDDM) is believed to be an autoimmune disorder with disturbed glucose/insulin metabolism, requiring life-long insulin replacement therapy (IRT), 30% of patients develop end-organ failure. We present our experience of cotransplantation of adipose tissue derived insulin-secreting mesenchymal stem cells (IS-AD-MSC) and cultured bone marrow (CBM) as IRT for these patients. Methods. This was a prospective open-labeled clinical trial to test efficacy and safety of IS-AD-MSC+CBM co-transplantation to treat IDDM, approved by the institutional review board after informed consent in 11 (males : females: 7 : 4) patients with 1–24-year disease duration, in age group: 13–43 years, on mean values of exogenous insulin requirement of 1.14 units/kg BW/day, glycosylated hemoglobin (Hb1Ac): 8.47%, and c-peptide levels: 0.1 ng/mL. Intraportal infusion of xenogeneic-free IS-AD-MSC from living donors, subjected to defined culture conditions and phenotypically differentiated to insulin-secreting cells, with mean quantum: 1.5 mL, expressing Pax-6, Isl-1, and pdx-1, cell counts: 2.1 × 103/μL, CD45−/90+/73+:40/30.1%, C-Peptide level:1.8 ng/mL, and insulin level: 339.3 IU/mL with CBM mean quantum: 96.3 mL and cell counts: 28.1 × 103/μL, CD45−/34+:0.62%, was carried out. Results. All were successfully transplanted without any untoward effect. Over mean followup of 23 months, they had a decreased mean exogenous insulin requirement to 0.63 units/kgBW/day, Hb1Ac to 7.39%, raised serum c-peptide levels to 0.38 ng/mL, and became free of diabetic ketoacidosis events with mean 2.5 Kg weight gain on normal vegetarian diet and physical activities. Conclusion. This is the first report of treating IDDM with insulin-secreting-AD-MSC+CBM safely and effectively with relatively simple techniques
Simulations of Recovery of Time-Varying Gravity from DECIGO Pathfinder
We simulated time-varying Earth's gravity field recovered from DPF to evaluate an impact of DPF and future satellite gradiometry mission on earth science. From hydrological water movement data and orbit information, gravity gradients to be measured at altitude about ~500km were generated. Errors caused by atmospheric and oceanic variations and instrumental noise were added. Monthly gravity fields were estimated solving normal equations between spherical harmonic coefficients and simulated gravity gradient data. Simulation results show that DPF likely provides monthly hydrological water storage change with spatial scale between 400 and 1000km. Sensitivities to large scale estimates depends on long-term stability of gravity gradient measurement, and errors in short scale estimates are caused by instrumental noise and imperfections in atmospheric and ocean model. With acceleration noise level is lower than ~5 x 10(exp -14) [m/s2/sqrtHz] at frequency higher than 3mHz, water storage changes at limited small basins will be provided by DPF. To monitor continental scale hydrological water movement, noise level must be lower than ~5 x 10(exp -14) [m/s2/sqrtHz] at frequency higher than 1mHz
Substructure in the Coma Cluster: Giants vs Dwarfs
The processes that form and shape galaxy clusters, such as infall, mergers
and dynamical relaxation, tend to generate distinguishable differences between
the distributions of a cluster's giant and dwarf galaxies. Thus the dynamics of
dwarf galaxies in a cluster can provide valuable insights into its dynamical
history. With this in mind, we look for differences between the spatial and
velocity distributions of giant (b18) galaxies in the Coma
cluster. Our redshift sample contains new measurements from the 2dF and WYFFOS
spectrographs, making it more complete at faint magnitudes than any previously
studied sample of Coma galaxies. It includes 745 cluster members - 452 giants
and 293 dwarfs. We find that the line-of-sight velocity distribution of the
giants is significantly non-Gaussian, but not that for the dwarfs. A battery of
statistical tests of both the spatial and localised velocity distributions of
the galaxies in our sample finds no strong evidence for differences between the
giant and dwarf populations. These results rule out the cluster as a whole
having moved significantly towards equipartition, and they are consistent with
the cluster having formed via mergers between dynamically-relaxed subclusters.Comment: 23 pages, 6 figures, to appear in Ap
Development of Department Writing Guide for Civil Engineering
This paper describes the development of a writing guide for a civil engineering department. Motivation for developing a writing guide came from several sources. Freshmen enrolled in an introduction to civil engineering course turned in writing assignments demonstrating a need for improvement. The introductory course is frequently taken concurrently with a required freshman level writing class and well before a required discipline specific advanced writing class, so this was generally expected. Continued issues in junior and senior level classes, however, have clarified the need for additional program focus on written communication. Students have continually expressed frustration at having to adapt to varying lab report expectations from different faculty members and, most importantly, capstone design reports have demonstrated that student writing is not at industry expectations.
The writing guide was a collaborative effort between civil engineering faculty and writing studies faculty. The initial phase focused on defining the content of the writing guide: reports (lab, project, etc.), memos, homework submittals, figures, tables, equations, professional e-mails, and references. The second phase was to develop an outline for the rubrics; the goal was for the rubrics to be general enough to be adapted by each faculty member for a given assignment, but still provide students with a consistent outline to assess their writing prior to submitting it for grade. Finally, in the third phase, the level of detail in the writing guide was discussed. In order to be useful, the writing guide was made specific enough for the students to use it to successfully complete writing assignments but general enough to allow individual faculty to adapt assignments toward the specific outcomes in each course. Above all else, the main goal of the writing guide is to prepare students for real world written communication. Therefore, it must not leave students with the impression that there is a template that can be applied regardless of audience. These concerns were considered during the development of the writing guide and will be part of in-class writing instruction within both civil engineering and writing courses.
Written work will be assessed using both university and ABET assessment processes. Example work collected as part of the ABET process from the Fall 2012 semester will be retroactively assessed using the newly developed rubrics. In addition, Fall 2014 work will be assessed as it is submitted. Spring 2015 work will represent the first semester using the department writing guide. Pre-writing guide assessments will be compared to assessments of writing after the department guide is introduced. By comparing work over the next several years, senior year writing submittals will be used to determine if a greater level of competency was achieved by students exposed to the writing guide for their entire undergraduate experience as compared to students who received the writing guide late in their undergraduate career
A pedagogic appraisal of the Priority Heuristic
We have explored how science and mathematics teachers made decisions when confronted with a dilemma in which a fictitious young woman, Deborah, may choose to have an operation that might address a painful spinal condition. We sought to explore the extent to which psychological heuristic models, in particular the Priority Heuristic, might successfully describe the decision-making process of these teachers and how an analysis of the role of personal and emotional factors in shaping the decision-making process might inform pedagogical design. A novel aspect of this study is that the setting in which the decision-making process is examined contrasts sharply with those used in psychological experiments. We found that to some extent, even in this contrasting setting, the Priority Heuristic could describe these teachers' decision-making. Further analysis of the transcripts yielded some insights into limitations on scope as well the richness and complexity in how personal factors were brought to bear. We see these limitations as design opportunities for educational intervention
Gauge-Invariant Initial Conditions and Early Time Perturbations in Quintessence Universes
We present a systematic treatment of the initial conditions and evolution of
cosmological perturbations in a universe containing photons, baryons,
neutrinos, cold dark matter, and a scalar quintessence field. By formulating
the evolution in terms of a differential equation involving a matrix acting on
a vector comprised of the perturbation variables, we can use the familiar
language of eigenvalues and eigenvectors. As the largest eigenvalue of the
evolution matrix is fourfold degenerate, it follows that there are four
dominant modes with non-diverging gravitational potential at early times,
corresponding to adiabatic, cold dark matter isocurvature, baryon isocurvature
and neutrino isocurvature perturbations. We conclude that quintessence does not
lead to an additional independent mode.Comment: Replaced with published version, 12 pages, 2 figure
A novel method for pulmonary research: Assessment of bioenergetic function at the air–liquid interface
AbstractAir–liquid interface cell culture is an organotypic model for study of differentiated functional airway epithelium in vitro. Dysregulation of cellular energy metabolism and mitochondrial function have been suggested to contribute to airway diseases. However, there is currently no established method to determine oxygen consumption and glycolysis in airway epithelium in air–liquid interface. In order to study metabolism in differentiated airway epithelial cells, we engineered an insert for the Seahorse XF24 Analyzer that enabled the measure of respiration by oxygen consumption rate (OCR) and glycolysis by extracellular acidification rate (ECAR). Oxidative metabolism and glycolysis in airway epithelial cells cultured on the inserts were successfully measured. The inserts did not affect the measures of OCR or ECAR. Cells under media with apical and basolateral feeding had less oxidative metabolism as compared to cells on the inserts at air-interface with basolateral feeding. The design of inserts that can be used in the measure of bioenergetics in small numbers of cells in an organotypic state may be useful for evaluation of new drugs and metabolic mechanisms that underlie airway diseases
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