Lund University

About: Lund University is a education organization based out in Lund, Sweden. It is known for research contribution in the topics: Population & Cancer. The organization has 42345 authors who have published 124676 publications receiving 5016438 citations. The organization is also known as: Lunds Universitet & University of Lund.

The likely impact of elevated [CO2], nitrogen deposition, increased temperature and management on carbon sequestration in temperate and boreal forest ecosystems: a literature review.

Abstract: Temperate and boreal forest ecosystems contain a large part of the carbon stored on land, in the form of both biomass and soil organic matter. Increasing atmospheric [CO2], increasing temperature, elevated nitrogen deposition and intensified management will change this C store. Well documented single-factor responses of net primary production are: higher photosynthetic rate (the main [CO2] response); increasing length of growing season (the main temperature response); and higher leaf-area index (the main N deposition and partly [CO2] response). Soil organic matter will increase with increasing litter input, although priming may decrease the soil C stock initially, but litter quality effects should be minimal (response to [CO2], N deposition, and temperature); will decrease because of increasing temperature; and will increase because of retardation of decomposition with N deposition, although the rate of decomposition of high-quality litter can be increased and that of low-quality litter decreased. Single-factor responses can be misleading because of interactions between factors, in particular those between N and other factors, and indirect effects such as increased N availability from temperature-induced decomposition. In the long term the strength of feedbacks, for example the increasing demand for N from increased growth, will dominate over short-term responses to single factors. However, management has considerable potential for controlling the C store.

Intestinal CD103+, but not CX3CR1+, antigen sampling cells migrate in lymph and serve classical dendritic cell functions

Abstract: Chemokine receptor CX3CR1+ dendritic cells (DCs) have been suggested to sample intestinal antigens by extending transepithelial dendrites into the gut lumen. Other studies identified CD103+ DCs in the mucosa, which, through their ability to synthesize retinoic acid (RA), appear to be capable of generating typical signatures of intestinal adaptive immune responses. We report that CD103 and CX3CR1 phenotypically and functionally characterize distinct subsets of lamina propria cells. In contrast to CD103+ DC, CX3CR1+ cells represent a nonmigratory gut-resident population with slow turnover rates and poor responses to FLT-3L and granulocyte/macrophage colony-stimulating factor. Direct visualization of cells in lymph vessels and flow cytometry of mouse intestinal lymph revealed that CD103+ DCs, but not CX3CR1-expressing cells, migrate into the gut draining mesenteric lymph nodes (LNs) under steady-state and inflammatory conditions. Moreover, CX3CR1+ cells displayed poor T cell stimulatory capacity in vitro and in vivo after direct injection of cells into intestinal lymphatics and appeared to be less efficient at generating RA compared with CD103+ DC. These findings indicate that selectively CD103+ DCs serve classical DC functions and initiate adaptive immune responses in local LNs, whereas CX3CR1+ populations might modulate immune responses directly in the mucosa and serve as first line barrier against invading enteropathogens.

Warmer climates boost cyanobacterial dominance in shallow lakes

Abstract: Dominance by cyanobacteria hampers human use of lakes and reservoirs worldwide. Previous studies indicate that excessive nutrient loading and warmer conditions promote dominance by cyanobacteria, but evidence from global scale field data has so far been scarce. Our analysis, based on a study of 143 lakes along a latitudinal transect ranging from subarctic Europe to southern South America, shows that although warmer climates do not result in higher overall phytoplankton biomass, the percentage of the total phytoplankton biovolume attributable to cyanobacteria increases steeply with temperature. Our results also reveal that the percent cyanobacteria is greater in lakes with high rates of light absorption. This points to a positive feedback because restriction of light availability is often a consequence of high phytoplankton biovolume, which in turn may be driven by nutrient loading. Our results indicate a synergistic effect of nutrients and climate. The implications are that in a future warmer climate, nutrient concentrations may have to be reduced substantially from present values in many lakes if cyanobacterial dominance is to be controlled.

Knee osteoarthritis after meniscectomy : Prevalence of radiographic changes after twenty-one years, compared with matched controls

Abstract: Objective. To study the long-term outcome of surgical removal of a meniscus in the knee with regard to radiographic signs of osteoarthritis (OA). Methods. Of the 123 patients who underwent an open meniscectomy due to an isolated meniscus tear in 1973 at Lund University Hospital, 107 were followed up 21 years later by clinical examination and by review of knee radiographs obtained with weight bearing. Seventy-nine of the 107 patients were men, and the mean age of the total study group at examination was 55 years (range 35-77). Sixty-eight sex- and age-matched individuals with healthy knees served as controls. Results. Mild radiographic changes were found in 76 (71%) of the knees, while more advanced changes, comparable with a Kellgren-Lawrence grade of 2 or higher, were seen in 51 (48%). The corresponding prevalence values in the control group were 12 (18%) and 5 (7%), respectively. The relative risk for the presence of the more advanced radiographic changes representing definite radiographic tibiofemoral OA was 14.0 (95% confidence interval 3.5-121.2), using age- and sex-matched pairs for comparison. No correlation with sex, localization to compartment, type of meniscus tear, or work load was found. Knee symptoms were reported twice as often in the study group as in the controls. Conclusion. Surgical removal of a meniscus following knee injury represents a significant risk factor for radiographic tibiofemoral OA, with a relative risk of 14.0 after 21 years.

Effects of Prenatal and Postnatal Methylmercury Exposure From Fish Consumption on Neurodevelopment Outcomes at 66 Months of Age in the Seychelles Child Development Study

Abstract: Context.—Human neurodevelopmental consequences of exposure to methylmercury (MeHg) from eating fish remain a question of public health concern.Objective.—To study the association between MeHg exposure and the developmental outcomes of children in the Republic of Seychelles at 66 months of age.Design.—A prospective longitudinal cohort study.Participants.—A total of 711 of 779 cohort mother-child pairs initially enrolled in the Seychelles Child Development Study in 1989.Setting.—The Republic of Seychelles, an archipelago in the Indian Ocean where 85% of the population consumes ocean fish daily.Main Outcome Measures.—Prenatal and postnatal MeHg exposure and 6 age-appropriate neurodevelopmental tests: the McCarthy Scales of Children's Abilities, the Preschool Language Scale, the Woodcock-Johnson Applied Problems and Letter and Word Recognition Tests of Achievement, the Bender Gestalt test, and the Child Behavior Checklist.Results.—The mean maternal hair total mercury level was 6.8 ppm and the mean child hair total mercury level at age 66 months was 6.5 ppm. No adverse outcomes at 66 months were associated with either prenatal or postnatal MeHg exposure.Conclusion.—In the population studied, consumption of a diet high in ocean fish appears to pose no threat to developmental outcomes through 66 months of age.