Vegetation exerts a greater control on litter decomposition than climate warming in peatlands.

Historically, slow decomposition rates have resulted in the accumulation of large amounts of carbon in northern peatlands. Both climate warming and vegetation change can alter rates of decomposition, and hence affect rates of atmospheric CO2 exchange, with consequences for climate change feedbacks. Although warming and vegetation change are happening concurrently, little is known about their relative and interactive effects on decomposition processes. To test the effects of warming and vegetation change on decomposition rates, we placed litter of three dominant species (Calluna vulgaris, Eriophorum vaginatum, Hypnum jutlandicum) into a peatland field experiment that combined warming.with plant functional group removals, and measured mass loss over two years. To identify potential mechanisms behind effects, we also measured nutrient cycling and soil biota. We found that plant functional group removals exerted a stronger control over short-term litter decomposition than did approximately 1 degrees C warming, and that the plant removal effect depended on litter species identity. Specifically, rates of litter decomposition were faster when shrubs were removed from the plant community, and these effects were strongest for graminoid and bryophyte litter. Plant functional group removals also had strong effects on soil biota and nutrient cycling associated with decomposition, whereby shrub removal had cascading effects on soil fungal community composition, increased enchytraeid abundance, and increased rates of N mineralization. Our findings demonstrate that, in addition to litter quality, changes in vegetation composition play a significant role in regulating short-term litter decomposition and belowground communities in peatland, and that these impacts can be greater than moderate warming effects. Our findings, albeit from a relatively short-term study, highlight the need to consider both vegetation change and its impacts below ground alongside climatic effects when predicting future decomposition rates and carbon storage in peatlands.

[Prophylactic application of medicated calcium sulphate in uncemented total hip prosthesis]. / Aplicación profiláctica de sulfato de calcio medicado en prótesis total de cadera no cementada.

The increase in total hip arthroplasty occurs by many factors, such as increasing life expectancy, improving surgical technique as well as innovating the design and implant material. However, despite technological advances, peri-prosthetic infection has remained one of the most devastating complications. This study evaluates the prophylactic application of calcium sulfate pearls medicated in the femoral canal and acetabular surface to prevent peri-prosthetic infections in patients who underwent total uncemented primary hip arthroplasty against a control group by measuring acute phase reactants. 146 patients, 67 were applied calcium sulfate pearls medicated and 79 prophylactic antibiotic intravenous in the period from 2013 to 2016. To perform the diagnosis of peri-prosthetic infection was assessed PCR associated with VSG, communication between fistula and prostheses and positive culture in 2 or more different sites. There was a decrease in the values of acute-phase reactants in patients who were given calcium sulfate pearls. 14 patients presented infection in the control group and 3 in the study group. The prophylactic use of calcium sulphate pearls within the medullary canal and acetabular surface is an option for the prophylaxis of peri-prosthetic infections, however the study deserves follow-up with more patients.

El incremento en la cirugía de artroplastía total de cadera es motivado por muchos factores, como el aumento en la expectativa de vida, mejoría continua en la técnica quirúrgica e innovaciones en el diseño y los materiales de los implantes que, sumados, han convertido a este procedimiento en una solución efectiva a la degeneración articular, con excelentes resultados. Sin embargo, a pesar de los avances tecnológicos, la infección periprotésica se ha mantenido como una de las complicaciones más devastadoras. Este estudio evalúa la aplicación profiláctica de perlas de sulfato de calcio medicadas en el canal femoral y superficie acetabular para prevenir infecciones periprotésicas en pacientes que fueron sometidos a una artroplastía total de cadera primaria no cementada contra un grupo control mediante la medición de reactantes de fase aguda y cultivo de líquido sinovial. Se sometieron al estudio 146 individuos: 67 a quienes se les aplicaron perlas de sulfato de calcio medicado y 79 a quienes se les aplicó antibiótico profiláctico intravenoso de Septiembre de 2013 a Agosto de 2016. Como método diagnóstico de infección periprotésica temprana se evaluaron la proteína C reactiva asociada a velocidad de sedimentación globular aumentada, una fístula que comunicara con la prótesis, cultivo positivo de dos o más sitios periprotésicos de líquido sinovial o tejido. Los resultados clínicos demostraron que hubo una disminución en los valores de los reactantes de fase aguda en los sujetos a quienes se les aplicaron las perlas de sulfato de calcio medicado. Se encontró que 14 personas presentaron infección en el grupo con profilaxis parenteral, comparado con tres del grupo con profilaxis local con perlas de sulfato de calcio medicado; ambos grupos con ceftriaxona. Se consideró que el uso profiláctico de perlas de sulfato de calcio dentro de canal medular y la superficie acetabular es una buena opción para prevenir infecciones periprotésicas en quienes han sido sometidos a una artroplastía total de cadera primaria no cementada; sin embargo el estudio amerita seguimiento con más pacientes para tener significancia estadística.