Protective effects of antiâ C5a peptide antibodies in experimental sepsis

We evaluated antibodies to different peptide regions of rat C5a in the sepsis model of cecal ligation and puncture (CLP) for their protective effects in rats. Rabbit polyclonal antibodies were developed to the following peptide regions of rat C5a: aminoâ terminal region (A), residues 1â 16; middle region (M), residues 17â 36; and the carboxylâ terminal region (C), residues 58â 77. With rat neutrophils, the chemotactic activity of rat C5a was significantly inhibited by antibodies with the following rank order: antiâ C > antiâ M â « antiâ A. In vivo, antibodies to the M and C (but not A) regions of C5a were protective in experimental sepsis, as determined by survival over a 10â day period, in a doseâ dependent manner. The relative protective efficacies of antiâ C5a preparations (in descending order of efficacy) were antiâ C â ¥ antiâ M â « antiâ A. In CLP rats, a delay in infusion of antibodies, which were injected at 6 or 12 h after CLP, still resulted in significant improvement in survival rates. These in vivo and in vitro data suggest that there are optimal targets on C5a for blockade during sepsis and that delayed infusion of antiâ C5a antibody until after onset of clinical evidence of sepsis still provides protective effects.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154417/1/fsb2fj000653fje-sup-0001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154417/2/fsb2fj000653fje.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154417/3/fsb2fj000653fje-sup-0002.pd

Understanding scientific study via process modeling

This paper argues that scientific studies distinguish themselves from other studies by a combination of their processes, their (knowledge) elements and the roles of these elements. This is supported by constructing a process model. An illustrative example based on Newtonian mechanics shows how scientific knowledge is structured according to the process model. To distinguish scientific studies from research and scientific research, two additional process models are built for such processes. We apply these process models: (1) to argue that scientific progress should emphasize both the process of change and the content of change; (2) to chart the major stages of scientific study development; and (3) to define “science”

Coadsorption of CO and Hydrogen on the Ir(111) Surface

The nonreactive coadsorption of CO and deuterium was investigated with temperature programmeddesorption and Fourier transform infrared reflection‐absorption spectroscopy. Both chemisorbed CO and deuterium adatoms block the adsorption of one another, and no replacement of either of the adsorbatesby the other could be detected. Both the peak position and the linewidth of the CO stretching frequency change upon coadsorption and, together with the thermal desorption spectra, indicate the formation of separate islands of the two adsorbates on the surface

Chemisorption of CO on the Ir(111) Surface: Adsorption And Desorption Kinetics Measured With in Situ Vibrational Spectroscopy

The kinetics of adsorption and desorption of carbon monoxide on Ir(111) have been investigated using the well-defined and carefully calibrated IR absorption peak position of the CO intramolecular stretching vibration as a nonintrusive coverage probe. Experiments were performed with time-resolved Fourier transform infrared reflection–absorption spectroscopy (TR-IRAS), which allows high-resolution measurements over a large pressure range between 1×10−8 role= presentation style= box-sizing: border-box; display: inline; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(51, 51, 51); font-family: Arial, sans-serif; position: relative; \u3e1×10−81×10−8 and 1×10−5 mbar role= presentation style= box-sizing: border-box; display: inline; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; color: rgb(51, 51, 51); font-family: Arial, sans-serif; position: relative; \u3e1×10−5 mbar1×10−5 mbar and surface temperature range between 390 and 500 K. The rate of desorption into vacuum is compared with the rate of desorption in the presence of a finite pressure of the desorbing gas. In this case, a flux-dependent enhancement of the desorption rate has been observed previously, which, if existent, should have an important impact on heterogeneously catalyzed reactions performed under high-pressure conditions. Most of these experiments, however, were performed using thermal desorptionspectroscopy, a nonequilibrium method. We have been able to measure all rate parameters that are essential to describe the desorptionin situ with TR-IRAS and have, thereby, clarified the disagreements that exist in the literature

Effects of backpack radio tags on tawny owls

Many high-density populations of wild ungulates have exerted strong negative impacts on their habitat. A decrease in forage quantity and quality may affect individual growth, fecundity, and survival, especially under harsh winter conditions. On Anticosti Island, Que´bec, Canada, browsing by introduced white-tailed deer (Odocoileus virginianus) negatively affected boreal forest composition. Since the preferred contemporary winter forage of deer, balsam fir (Abies balsamea), has been almost completely extirpated from the island at browse height, deer are forced to increase the proportion of normally avoided forage, such as white spruce (Picea glauca), in their winter diet. We predicted that an increase in the proportion of white spruce in the diet would have detrimental effects on deer body condition and would affect their behavior and life history traits. We experimentally simulated a deterioration of winter forage quality in semi-natural enclosures by increasing the proportion of white spruce in the diet and examined the effects of winter diet quality on 1) forage intake, 2) body condition loss, 3) activity budget, and 4) survival of whitetailed deer fawns. Fawns fed the poor-quality diet maintained a higher forage intake rate throughout the winter than fawns fed the control diet, suggesting a compensatory response to the decrease of forage quality by consuming more forage during winter. Body mass decreased over the winter, but we did not observe any significant effects of diet quality on body mass loss. Diet quality did not influence the activity budget of fawns, but deer decreased activity in cold weather. The main determinant of overwinter survival was individual body mass in early winter. Our study suggests that deer have adapted to the extreme conditions encountered on Anticosti (i.e., harsh and long winters, low-quality browse, and a high-density population). Even though white spruce stands are gradually replacing balsam fir stands, our results suggest that deer on Anticosti could maintain a high-density population by increasing the amount of white spruce in their diet. However, future studies are necessary to address the long-term effects of a diet dominated by white spruce on deer body condition, survival, and reproduction under natural conditions