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As demands for mobile broadband services and ubiquitous network coverage in our societies are increasing, the mobile communication network infrastructure has to be expanded. Concurrently, the technical infrastructure of mobile communication technologies (base stations) raises the public's concerns about health risks due to electromagnetic fields (EMF). By applying conjoint analyses, the study empirically investigates the relationship between mobile data demands, different base station locations, the prevalence of perceived health complaints, and the impact of compensation payments. Findings show that health concerns are the most critical factor for mobile network communication scenario preferences, followed by data rate availability. In the decision scenarios, base station location and compensation payments played a minor role. Two user groups, cellphone and smart phone users who differ in their sensitivity regarding health concerns and data demands, were identified by segmentation analysis. By means of a sensitivity analysis, different mobile communication network scenarios were analyzed. Outcomes show the importance of integrating users’ preferences into the design of mobile communication networks. This especially refers to an increased sensitivity regarding health concerns in cellphone users and minimum requirements for data rates at least sufficient for the usage of mobile Internet services for smart phone users. 相似文献
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Luciana Ines Oklander Martin M. Kowalewski Daniel Corach 《International journal of primatology》2010,31(5):813-832
Human-induced habitat fragmentation might seriously affect behavioural patterns and the survival of species whose ecological
requirements strongly depend on specific environmental conditions. We compared the genetic structure and dispersal patterns
of 2 populations of Alouatta caraya (Plathyrrhini, Atelidae) to understand how habitat reduction and fragmentation affect gene flow in this species. We sampled
individuals from 7 groups living in continuous forest (CF, n = 46, 22 males and 24 females), and 11 groups that inhabit a fragmented forest (FF, n = 50, 24 males and 26 females). FST values based on 11 microsatellite loci showed a recent genetic differentiation among
groups in the FF. In contrast, the CF showed no differentiation among groups. Further, FST values between sexes, as well as
kinship relationships, also exhibited differences between habitats. In the CF, both males and females disperse, leading to
nondifferentiated groups composed of adults that are not close relatives. Conversely, in the FF, some groups are differentiated,
males disperse more than females, and groups are composed of closely related adult females. Our results suggest that habitat
fragmentation modifies the dispersal patterns of black-and-gold howlers. These differences between habitats may reflect a
reduced gene flow, providing genetic evidence that suggests that habitat fragmentation severely limits the howler’s ability
to disperse. An increasing level of isolation due to uncontrolled deforestation may cause similar loss of genetic diversity
on other arboreal primates, and nonprimates that depend on forest continuity to disperse, reducing their abilities to cope
with environmental changes. 相似文献
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W Siems J Kowalewski H David T Grune M Bimmler 《Cellular and molecular biology, including cyto-enzymology》1991,37(2):213-226
An increased formation of oxygen free radicals in the reperfused rat small intestine is concluded from accumulations of oxidized glutathione, of thiobarbituric acid-reactive substances and of 4-hydroxynonenal. Xanthine oxidase inhibition prevented these biochemical changes. The histological and electronmicroscopic studies of intestinal sucosa showed significant structural deteriorations already at the end of the ischemic period obviously due to disturbances of cellular energy metabolism. The extent of dosage was increased during the reperfusion without qualitative changes of the pattern of structural dosage. The beneficial effects of oxypurinol on biochemical criteria which occurred already in the early phase of reperfusion were not reflected in significant morphological differences within the first hour of reperfusion. Differences of morphological findings between oxypurinol-treated and untreated animals could be observed after longer periods of reperfusion--during the regeneration of the tissue. 相似文献
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Teng YK Verburg RJ Verpoort KN Diepenhorst GM Bajema IM van Tol MJ Jol-van der Zijde EC Toes RE Huizinga TW van Laar JM 《Arthritis research & therapy》2007,9(5):R106
In order to identify pathogenic correlates of refractory rheumatoid arthritis (RA), antibodies against anti-cyclic citrullinated
protein (ACPAs) were investigated in RA patients in whom the dysregulated immune system had been ablated by high-dose chemotherapy
(HDC) and autologous haematopoietic stem cell transplantation (HSCT). Six patients with refractory RA were extensively characterized
in terms of levels of total immunoglobulins, RA-specific autoantibodies (ACPAs and rheumatoid factor) and antibodies against
rubella, tetanus toxoid (TT) and phosphorylcholine before and after HDC plus HSCT. Additionally, the avidity of ACPAs was
measured before and after treatment and compared with the avidity of TT antibodies following repeated immunizations. Synovial
biopsies were obtained by arthroscopy before HDC plus HSCT, and analyzed by immunohistochemistry. In the three patients with
clinically long-lasting responses to HDC plus HSCT (median 423 days), significant reductions in ACPA-IgG levels after therapy
were observed (median level dropped from 215 to 34 arbitrary units/ml; P = 0.05). In contrast, stable ACPA-IgG levels were observed in three patients who relapsed shortly after HDC plus HSCT (median
of 67 days). Clinical responders had ACPA-IgG of lower avidity (r = 0.75; P = 0.08) and higher degree of inflammation histologically (r = 0.73; P = 0.09). Relapse (after 38 to 530 days) in all patients was preceded by rising levels of low avidity ACPA-IgG (after 30 to
388 days), in contrast to the stable titres of high avidity TT antibodies. In conclusion, humoral autoimmune responses were
differentially modulated by immunoablative therapy in patients with synovial inflammation and low avidity ACPA-IgG autoantibodies
as compared with patients with high levels of high avidity ACPA-IgG. The distinct clinical disease course after immunoablative
therapy based on levels and avidity of ACPA-IgG indicates that refractory RA is not a single disease entity. 相似文献
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