Search results for "unity"
showing 10 items of 3852 documents
Human immunosenescence: is it infectious?
2005
Morbidity and mortality due to infectious disease is greater in the elderly than in the young, at least partly because of age-associated decreased immune competence, which renders individuals more susceptible to pathogens. This susceptibility is particularly evident for novel infectious agents such as in severe acute respiratory syndrome but is also all too apparent for common pathogens such as influenza. Many years ago, it was noted that the elderly possessed oligoclonal expansions of T cells, especially of CD8(+) cells. At the same time, it was established that cytomegalovirus (CMV) seropositivity was associated with many of the same phenotypic and functional alterations to T-cell immunit…
Is immunosenescence infectious?
2004
Abstract Herpes viruses are endemic. Once established, the virus is never eliminated but persists throughout life. The fraction of infected individuals gradually increases with age, such that the majority of elderly people are cytomegalovirus (CMV) + , Epstein–Barr virus (EBV) + and Varicella + . Clinically relevant reactivation of Varicella causes painful shingles; CMV reactivation can cause fatal pneumonia. Overt reactivation, even in the very elderly, occurs only in immunocompromised individuals; however, the necessity for maintaining immunity to these viruses is costly. We argue that this cost is not only reflected in the requirement for continuous immunosurveillance against these virus…
Phosphatidylserine counteracts physiological and pharmacological suppression of humoral immune response
1990
Phosphatidylserine (PS) is a necessary cofactor for protein kinase C (PKC) activation, and changes in the synthesis of PS have been shown to participate in the mechanism(s) involved in the transmembrane signaling of interleukin 1 (IL-1). In view of the age-associated defects in T-cell functions, in the present study we have addressed the question of whether an in vivo treatment with PS might interfere with such processes. Furthermore, the effect of an in vitro treatment with PS in human peripheral blood monocytes (PBMC) or splenocytes activated with a lectin mitogen, on the expression of IL-2 receptor, was assessed. While the process of ageing was accompanied by a marked decline of humoral …
Inflammation, genes and zinc in ageing and age-related diseases.
2006
Lifelong antigenic burden determines a condition of chronic inflammation, with increased lymphocyte activation and pro-inflammatory cytokine production. A large number of studies have documented changes in Zn metabolism in experimental animal models of acute and chronic inflammation and in human chronic inflammatory diseases. In particular, modification of zinc plasma concentration as well as intracellular disturbance of antioxidant intracellular pathways have been found associated to age-related inflammatory diseases, like atherosclerosis. Zinc deficiency is extremely diffused in aged people that are educated to avoid meat and other high Zn-content foods due to fear of cholesterol. Rather,…
Prostaglandin D2 regulates joint inflammation and destruction in murine collagen-induced arthritis.
2012
Item does not contain fulltext OBJECTIVE: Prostaglandin D2 (PGD2) may exert proinflammatory or antiinflammatory effects in different biologic systems. Although this prostanoid and the enzymes responsible for its synthesis are up-regulated by interleukin-1beta (IL-1beta) in human chondrocytes in vitro, the role of PGD2 in arthritis remains unclear. This study was undertaken to investigate the role of PGD2 in the inflammatory response and in joint destruction during the development of collagen-induced arthritis (CIA) in mice. METHODS: PGD2 and cytokine levels in mice with CIA were determined by enzyme-linked immunosorbent assay. Expression of hematopoietic PGD synthase (h-PGDS), lipocalin-typ…
Agricultural management affects the response of soil bacterial community structure and respiration to water-stress
2013
International audience; Soil microorganisms are responsible for organic matter decomposition processes that regulate soil carbon storage and mineralisation to CO2. Climate change is predicted to increase the frequency of drought events, with uncertain consequences for soil microbial communities. In this study we tested the hypothesis that agricultural management used to enhance soil carbon stocks would increase the stability of microbial community structure and activity in response to water-stress. Soil was sampled from a long-term field trial with three soil carbon management systems and was used in a laboratory study of the effect of a dry wet cycle on organic C mineralisation and microbi…
Assessing the impact of agri-environmental schemes on the eco-efficiency of rain-fed agriculture
2012
This paper analyses the impact of the Agri-environmental Extensification Scheme for the Protection of Flora and Fauna (F&F Scheme) on the eco-efficiency of a sample of dryland farms in the Spanish region of Castile and Leon. Using Data Envelopment Analysis (DEA) and the so-called program decomposition approach to efficiency measurement, we explore whether or not the production technology of the farms included in the F&F Scheme is more eco-efficient than the technology used by farms that are not included in the Scheme. The re-sults obtained confirm the foregoing hypothesis, providing evidence that environmental pres-sures could be reduced if all farms adopted the F&F Scheme technology. Furth…
Short-term effects of different tillage in a sustainable farming system on nematode community structure
2000
This study investigated the effects of different tillage practices on the nematode community structure. The different tillage systems were: untilled control, conventional deep plough, two-layer plough and cultivator. Sampling was carried out in a field experiment at Worrstadt-Rommersheim (Rhineland-Palatinate, Germany) in order to study the effects of these tillage systems in a sustainable farming system. Soil samples were taken every 3 months from June 1994 to March 1995 and divided into two depths of 0–10 and 10–20 cm in order to study the vertical distribution of nematode density and community structure. Nematode density was significantly reduced after the first tillage. The second tilla…
Optimal timing of power line rights-of-ways management for the conservation of butterflies
2012
Habitat loss, fragmentation, and degradation are the main threats to biodiversity. Human activities also create new habitat types that might fulfil ecological requirements for a variety of species. This study investigates whether the vegetation clearing (=shrub and tree cutting) on drained mire patches on power line rights-of-ways (ROWs) keep plant communities in an early successional stage and thus provide habitats for mire specialist and non-mire butterflies. It was further studied what would be the optimal clearing interval in terms of butterfly species richness and abundance. The results show that tree height, especially the height of birch, increases linearly over the 7-year period fol…
Weed communities of rice fields in the central Pamir Alai Mountains (Tajikistan, Middle Asia)
2013
The study present results of geobotanical investigations conducted in rice fields in the central Pamir Alai Mts (Tajikistan, Middle Asia), mainly within Syr-Daria, Pyandzh, Zeravshan, Kafirnigan, Khanaka and Surkhandaria river valleys in the years 2009–2011. The researches were focused on classification of plant communities developing within this poorly investigated area. Habitat conditions were checked including conductometry, pH reaction, temperature, depth of water and, for several plots, also soil structure. Altogether 114 phytosociological relevés using the Braun-Blanquet method were sampled. The analyses classified the vegetation into 28 communities including 24 associations. Five new…