5,015 research outputs found
The In Vitro Bactericidal Activity of Normal and Activated Mouse Macrophages against Salmonella typhimurium C5sr
A comparison of the in vitro bactericidaL activity of normaL and activated macrophages indicated that killing
of the viruLent strain of opsonized Salmonella typhimurium C5sr by normaL macrophages was enhanced
by the presence of fresh serum in the cuLture medium. In contrast, there was no such requirement for the
bactericidaL activity of activated macrophages. The enhanced killing ojfthe bacteria by activated macrophages
occurred both in the presence and absence of serum, and this was not accounted for by the existence of macrophagebound
immunogLobuLin. The factors in normaL rabbit serum which potentiated the killing of bacteria by
normaL macrophages were suspected to be components of the compLement system. Heat-stabLe jactors
(immunogLobuLins) in normaL rabbit serum were effective only if they were surface bound immunogLobuLins
Heterogeneity of Mouse Macrophages in Terms of Their Bactericidal Activity
These studies confirm that not all cells in a macrophage population express efective bactericidal functions. Two
subsets of macrophages with cell-surface markers recognized by two monoclonal antibodies, designated M43 and
1\157 were shown to be involved in the bacteicidal activity of a macrophage population. B)' indirect
radio immunoassay (RIA), it was found that these two subset markers were expressed more on the 5tu/ace of
activated manipulates than on normal cells. It seems possible that these two markers may se11Je as markers for
macrophage activation in terms of enhanced bactericidal activity
Large-angle scattering and quasi-elastic barrier distributions
We study in detail the barrier distributions extracted from large-angle
quasi-elastic scattering of heavy ions at energies near the Coulomb barrier.
Using a closed-form expression for scattering from a single barrier, we compare
the quasi-elastic barrier distribution with the corresponding test function for
fusion. We examine the isocentrifugal approximation in coupled-channels
calculations of quasi-elastic scattering and find that for backward angles, it
works well, justifying the concept of a barrier distribution for scattering
processes. This method offers an interesting tool for investigating unstable
nuclei. We illustrate this for the Mg + Pb reaction, where the
quadrupole collectivity of the neutron-rich Mg remains to be clarified
experimentally.Comment: 26 pages, 10 eps figure
Improved resource use decisions and actions through remote sensing
Operational uses of remote sensing for improving management decisions and actions concerning resource uses are considered in terms of first generation, or direct-action; and second generation or indirect, delayed-action applications. From among applications completed during 1974-75, seven case studies are offered in illustration of the many contrasts which can be drawn between first and second generation application studies. These include: (1) multi-agency river basin planning; (2) corridor assessment and route location for highway location together with improvement of county-level planning decisions; (3) improving timber management practices; (4) enforcement of new state statutes; (5) county-wide open space preservation; (6) land value reappraisal relative to property tax equalization; and (7) optimizing agri-business processing plant locations
Density Matrix Renormalization for Model Reduction in Nonlinear Dynamics
We present a novel approach for model reduction of nonlinear dynamical
systems based on proper orthogonal decomposition (POD). Our method, derived
from Density Matrix Renormalization Group (DMRG), provides a significant
reduction in computational effort for the calculation of the reduced system,
compared to a POD. The efficiency of the algorithm is tested on the one
dimensional Burgers equations and a one dimensional equation of the Fisher type
as nonlinear model systems.Comment: 12 pages, 12 figure
Health benefits of joint replacement surgery for patients with osteoarthritis: prospective evaluation using independent assessments in Scotland
Study objectives - To determine extent of change in psychological, functional, and social health after knee and hip joint replacement surgery using independent assessments. Design - Patients were recruited before surgery and interviewed preoperatively, three months after surgery, and nine months after surgery. Interviews were conducted in the patients' own homes. Setting - Two orthopaedic surgery units in Scotland. Participants - A consecutive sample of 107 patients with osteoarthritis having primary replacement of the knee or hip. Main outcome measures - Assessments of depression, anxiety, pain, functional activity, informal care, and formal service utilisation were made at three time points. Main results - Anxiety and pain were significantly reduced and functional activity levels significantly increased after surgery. While gains in anxiety and pain reduction occurred between the preoperative and three month assessments, gains in activity were made between the three month and nine month assessments. Although pain was reduced and activity increased, levels of depression were unchanged after surgery. Patients reported need for assistance with fewer activities after surgery, but increases in the use of formal services and increases in the number of hours per week of informal support received were observed at both three month and nine month follow up. Conclusions - The main benefit of joint replacement surgery is pain relief. Gains in functional activity, particularly mobility and leisure activities are made by many patients. Paradoxically, surgery for osteoarthritis seems to act as a 'gateway' to increases in formal and informal community support, which are maintained into the longer term
Retrospective Epidemiologic Analysis of Influenza Pandemics in Arkansas, A
This study compares influenza mortality in Arkansas during the pandemics of: 1918 (aka Spanish flu), 1957, 1968, and 2009 (H1N1, aka Swine flu). Death certificate and U.S. census data were gathered and analyzed for statistical differences in mortalities based on sex, age, and geographic regions of Arkansas for each pandemic. The geographic regions were defined by the five Public Health Units classified by the Arkansas Department of Health. Regional mortalities were also analyzed across all pandemics to investigate how the different pandemics affected each individual region. Chi-square analyses for each pandemic showed only the 1918 pandemic had statistical differences between male and female mortalities (p0.5). Data showed urban regions sustained higher proportional mortalities than rural regions. Over time, the four pandemics resulted in decreased flu mortalities throughout the state. Regional mortality rates suggest areas for increased public health efforts during future influenza outbreaks in Arkansas, and more efficient distribution of resources may reduce mortality rates of future pandemics
Evaluation of Education and Other Influential Factors on the Perceptions of Influenza Vaccinations
Influenza is a potentially deadly contagious viral infection that attacks the respiratory system. The 1918 influenza pandemic infected approximately 1/3 of the world’s population and resulted in an estimated 50 million deaths globally. Research has led to the production of influenza vaccinations. Unfortunately, there continues to be influenza epidemics that are responsible for killing numerous people annually. One reason for the continued death toll from influenza is the lack of people receiving a yearly flu vaccination. In order to gain more public acceptance for influenza vaccinations, it is important to understand the factors influencing the choice to be vaccinated. A study was conducted on 191 undergraduate general psychology students at the University of Central Arkansas to test if specific factors determine the predictability of vaccination acceptance. Education and positive influential factors toward flu vaccinations are two important factors presented in the study that have influence on participants receiving the vaccine. The study results are beneficial in understanding why people reject flu vaccines and what can be done to reverse those decisions
Evidence of Erosional Self-Channelization of Pyroclastic Density Currents Revealed by Ground-Penetrating Radar Imaging at Mount St. Helens, Washington (USA)
The causes and effects of erosion are among the least understood aspects of pyroclastic density current (PDC) dynamics. Evidence is especially limited for erosional self-channelization, a process whereby PDCs erode a channel that confines the body of the eroding flow or subsequent flows. We use ground-penetrating radar imaging to trace a large PDC scour and fill from outcrop to its point of inception and discover a second, larger PDC scour and fill. The scours are among the largest PDC erosional features on record, at \u3e200 m wide and at least 500 m long; estimated eroded volumes are on the order of 106 m3. The scours are morphologically similar to incipient channels carved by turbidity currents. Erosion may be promoted by a moderate slope (5–15°), substrate pore pressure retention, and pulses of increased flow energy. These findings are the first direct evidence of erosional self-channelization by PDCs, a phenomenon that may increase flow velocity and runout distance through confinement and substrate erosion
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