2,090 research outputs found
Studies on the rejection of the transplanted homologous dog liver.
Dogs in which livers have been replaced with hepatic homografts usually die in 5 to 10 days. Liver metabolism is not detectably abnormal at first, but gradual deterioration of function commences on the fourth or fifth day. There was histologic evidence of rejection in all dogs dying after 4 days. This ranged from minimal mononuclear infiltration to almost complete destruction of parenchyma. In the longest survivor, 20 1/2 days, histologic changes were less profound than in many animals dying earlier. Widespread histologic changes were found in host reticuloendothelial system, involving the bone marrow, kidneys, lungs, lymph nodes, and other tissues. These consisted of fixed tissue proliferation and infiltration of mononuclear cells, principally plasma cells. These changes were thought to be due to a general host reticuloendothelial response to the antigenic stimulus of the homograft
Interview with Dr. Lisa Brock, Part 1
Part 1 of two part interview with Dr. Lisa Brock recorded on April 29, 2015. Dr. Brock is interviewed by Kalamazoo College student Buffy Satchwell as a part of SHARE\u27s (formerly known as the Southwest Michigan Black Heritage Society) Baldwin Archive Engaging the Wisdom Project with Kalamazoo College. During the interview Dr. Brock discusses the following topics: History of parents and grandparents living in southern Ohio; Childhood memories of neighborhood, growing up in a tight-knit black community; Experiences of education from elementary through high school; Attending Oberlin college and Howard University, a HBCU; Memories of influences that motivated involvement in activism; Story of seeing Martin Luther King, Jr. speak; Memories of 1968 in Washington D.C during the riots and the Civil Rights Movement; Discussion of African American history; Stories of activist work in countries like Cuba, Mozambique, and South Africa; Discussion of work in the Anti-Apartheid movement in the 1980s and 90s.
Additional files include full transcription and abstract (includes content timestamps).https://scholarworks.wmich.edu/engaging-the-wisdom/1013/thumbnail.jp
Interview with Dr. Lisa Brock, Part 2
Part 2 of two part interview with Dr. Lisa Brock recorded on May 15, 2015. Dr. Brock is interviewed by Kalamazoo College student Buffy Satchwell as a part of SHARE\u27s (formerly known as the Southwest Michigan Black Heritage Society’s) Baldwin Archive Engaging the Wisdom Project with Kalamazoo College. During this interview Dr. Brock discusses the following topics: Discussion of social justice work at Kalamazoo College with the Arcus Center; Comparison of past approaches in Civil Rights movements to current movements; Memories of high school and influential literature regarding social activism; Discussion of American history in the South and changes from the Civil Rights Movement; Examples in history of Apartheid and slavery; Story about Brock’s grandmother; Family histories learned by interviewing her grandparents; Discussion of the value of learning African-American history; Challenges faced as an African-American woman.
Additional files include full transcription and abstract (includes content timestamps).https://scholarworks.wmich.edu/engaging-the-wisdom/1015/thumbnail.jp
Reconstructive problems in canine liver homotransplantation with special reference to the postoperative role of hepatic venous flow
The homologous canine liver has been transplanted to recipient animals in which total hepatectomy and splenectomy have been performed. The longest survival after placement of the liver homograft was 20 1/2 days. Protection from hepatic ischemia for as long as 2 hours was obtained by cooling the donor liver to 10 to 20 degrees C. The arterial supply was restored through a hepatic artery-aortic pedicle which was removed in continuity with the liver and anastomosed to the descending aorta of the recipient. Internal biliary drainage was established. The volume of venous flow transmitted to the transplanted liver has been shown to be an important determinant of success. When this was excessive, as when both the portal and inferior caval flows were directed through the liver, hepatic and splanchnic beds. When the portal flow was normal or reduced, outflow block rarely occurred. An attempt has been made to relate the development of outflow block as it occurred in the transplanted liver to other circumstances, including hemorrhagic shock, in which similar phenomena have been observed
Humusmenge in der Ackerkrume nach langjährig differenzierter Intensität der Grundbodenbearbeitung
The aim of the present study was to investigate the impacts of different tillage intensity
on the quantity of soil organic matter in topsoils of seven long-term trials. Tillage
intensity was found to affect both bulk density and Ct-contents, whereas total C
quantity did not differ significantly between tillage treatments in all trials even though a
high C accumulation in the reduced tillage system was visible in one trial. As for
humus balancing, a consideration of tillage intensity is not supported by these results
Organic aerosol formation downwind from the Deepwater Horizon oil spill.
A large fraction of atmospheric aerosols are derived from organic compounds with various volatilities. A National Oceanic and Atmospheric Administration (NOAA) WP-3D research aircraft made airborne measurements of the gaseous and aerosol composition of air over the Deepwater Horizon (DWH) oil spill in the Gulf of Mexico that occurred from April to August 2010. A narrow plume of hydrocarbons was observed downwind of DWH that is attributed to the evaporation of fresh oil on the sea surface. A much wider plume with high concentrations of organic aerosol (>25 micrograms per cubic meter) was attributed to the formation of secondary organic aerosol (SOA) from unmeasured, less volatile hydrocarbons that were emitted from a wider area around DWH. These observations provide direct and compelling evidence for the importance of formation of SOA from less volatile hydrocarbons
Atmospheric emissions from the deepwater Horizon spill constrain air-water partitioning, hydrocarbon fate, and leak rate
The fate of deepwater releases of gas and oil mixtures is initially determined by solubility and volatility of individual hydrocarbon species; these attributes determine partitioning between air and water. Quantifying this partitioning is necessary to constrain simulations of gas and oil transport, to predict marine bioavailability of different fractions of the gas-oil mixture, and to develop a comprehensive picture of the fate of leaked hydrocarbons in the marine environment. Analysis of airborne atmospheric data shows massive amounts (∼258,000 kg/day) of hydrocarbons evaporating promptly from the Deepwater Horizon spill; these data collected during two research flights constrain air-water partitioning, thus bioavailability and fate, of the leaked fluid. This analysis quantifies the fraction of surfacing hydrocarbons that dissolves in the water column (∼33% by mass), the fraction that does not dissolve, and the fraction that evaporates promptly after surfacing (∼14% by mass). We do not quantify the leaked fraction lacking a surface expression; therefore, calculation of atmospheric mass fluxes provides a lower limit to the total hydrocarbon leak rate of 32,600 to 47,700 barrels of fluid per day, depending on reservoir fluid composition information. This study demonstrates a new approach for rapid-response airborne assessment of future oil spills. Copyright 2011 by the American Geophysical Union
Paternity and Dominance Loss in Male Breeders: The Cost of Helpers in a Cooperatively Breeding Mammal
Paternity insurance and dominance tenure length are two important components of male reproductive success, particularly in species where reproduction is highly skewed towards a few individuals. Identifying the factors affecting these two components is crucial to better understand the pattern of variation in reproductive success among males. In social species, the social context (i.e. group size and composition) is likely to influence the ability of males to secure dominance and to monopolize reproduction. Most studies have analyzed the factors affecting paternity insurance and dominance tenure separately. We use a long term data set on Alpine marmots to investigate the effect of the number of subordinate males on both paternity insurance and tenure of dominant males. We show that individuals which are unable to monopolize reproduction in their family groups in the presence of many subordinate males are likely to lose dominance the following year. We also report that dominant males lose body mass in the year they lose both paternity and dominance. Our results suggest that controlling many subordinate males is energetically costly for dominant males, and those unable to support this cost lose the control over both reproduction and dominance. A large number of subordinate males in social groups is therefore costly for dominant males in terms of fitness
Recruitment of aged donor heart with pharmacological stress echo. A case report
BACKGROUND: The heart transplant is a treatment of the heart failure, which is not responding to medications, and its efficiency is already proved: unfortunately, organ donation is a limiting step of this life-saving procedure. To counteract heart donor shortage, we should screen aged potential donor hearts for initial cardiomyopathy and functionally significant coronary artery disease. Donors with a history of cardiac disease are generally excluded. Coronary angiography is recommended for most male donors older than 45 years and female donors older than 50 years to evaluate coronary artery stenoses. A simpler way to screen aged potential donor hearts for initial cardiomyopathy and functionally significant coronary artery disease should be stress echocardiography. CASE REPORT: A marginal donor (A 57 year old woman meeting legal requirements for brain death) underwent a transesophageal (TE) Dipyridamole stress echo (6 minutes accelerated protocol) to rule out moderate or severe heart and coronary artery disease. Wall motion was normal at baseline and at peak stress (WMSI = 1 at baseline and peak stress, without signs of stress inducible ischemia). The pressure/volume ratio was 9.6 mmHg/ml/m(2 )at baseline, increasing to 14 mmHg/ml/m(2 )at peak stress, demonstrating absence of latent myocardial dysfunction. The marginal donor heart was transplanted to a recipient "marginal" for co-morbidity ( a 63 year old man with multiple myeloma and cardiac amyloidosis , chronic severe heart failure, NYHA class IV). Postoperative treatment and early immunosuppressant regimen were performed according to standard protocols. The transplanted heart was assessed normal for dimensions and ventricular function at transthoracic (TT) echocardiography on post-transplant day 7. Coronary artery disease was ruled out at coronary angiography one month after transplant; left ventriculography showed normal global and segmental LV function of the transplanted heart. CONCLUSION: For the first time stress echo was successfully used in the critical theater of screening potential donor hearts. This method is enormously more feasible, less expensive, and more environmentally sustainable than any possible alternative strategy based on stress scintigraphy perfusion imaging or coronary angiography. The selection of hearts "too good to die" on the basis of bedside resting and stress echo can be a critical way to solve the mismatch between donor need and supply
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