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31.
Historical biogeography and the evolution of the latitudinal gradient of species richness in the Papionini (Primata: Cercopithecidae) 总被引:1,自引:0,他引:1
MONIKA BÖHM PETER J. MAYHEW 《Biological journal of the Linnean Society. Linnean Society of London》2005,85(2):235-246
We apply historical biogeography techniques to the macaques, baboons and their relatives (Primata: Papionini) and relate the inferred history of range shifts, and associated evolutionary events, to the latitudinal distribution of extant species, which is strongly tropical. The results of reversible parsimony, weighted ancestral area and dispersal-vicariance analyses all agree that Central Africa was part of the range of the ancestor of the tribe. Tropical regions with high current species richness (Central Africa, South-east Asia, Indonesia) have: (1) had a relatively long history of occupation, (2) experienced both a greater number and a greater average rate of speciation events and (3) given rise to more dispersal events to other regions. However, nested sister-taxon comparisons across the tribe show no overall association between differences in latitude and differences in rates of cladogenesis. Our historical reconstructions are largely consistent with previous hypotheses and fossil data, and suggest that both the passage of time since colonization and rates of cladogenesis have enhanced tropical species richness. Historical biogeography may thus considerably aid understanding of this and other spatial problems in macroecology. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 85 , 235–246. 相似文献
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We examined the possible effects of elemental mercury vapor on the liver of the female rats. We divided the animals into an untreated control group and an experimental group that was exposed to mercury vapor for 45 days. Liver samples were obtained for histological and stereological analysis. The total liver, parenchyma and sinusoid volumes were increased significantly in the mercury vapor treated group compared to controls. Also, the mean density, total number and mean nuclear diameter of hepatocytes, except for binucleated hepatocytes, was decreased in the experimental group compared to controls. Light and electron microscopy revealed alterations of liver structure of the experimental animals compared to controls. 相似文献
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Mohamed M Thabet Thomas WJ Huizinga Désirée M van der Heijde Annette HM van der Helm-van Mil 《Arthritis research & therapy》2009,11(5):1-9
Introduction
Evidence suggests that citrullinated fibrin(ogen) may be a potential in vivo target of anticitrullinated protein/peptide antibodies (ACPA) in rheumatoid arthritis (RA). We compared the diagnostic yield of three enzyme-linked immunosorbent assay (ELISA) tests by using chimeric fibrin/filaggrin citrullinated synthetic peptides (CFFCP1, CFFCP2, CFFCP3) with a commercial CCP2-based test in RA and analyzed their prognostic values in early RA.Methods
Samples from 307 blood donors and patients with RA (322), psoriatic arthritis (133), systemic lupus erythematosus (119), and hepatitis C infection (84) were assayed by using CFFCP- and CCP2-based tests. Autoantibodies also were analyzed at baseline and during a 2-year follow-up in 98 early RA patients to determine their prognostic value.Results
With cutoffs giving 98% specificity for RA versus blood donors, the sensitivity was 72.1% for CFFCP1, 78.0% for CFFCP2, 71.4% for CFFCP3, and 73.9% for CCP2, with positive predictive values greater than 97% in all cases. CFFCP sensitivity in RA increased to 80.4% without losing specificity when positivity was considered as any positive anti-CFFCP status. Specificity of the three CFFCP tests versus other rheumatic populations was high (> 90%) and similar to those for the CCP2. In early RA, CFFCP1 best identified patients with a poor radiographic outcome. Radiographic progression was faster in the small subgroup of CCP2-negative and CFFCP1-positive patients than in those negative for both autoantibodies. CFFCP antibodies decreased after 1 year, but without any correlation with changes in disease activity.Conclusions
CFFCP-based assays are highly sensitive and specific for RA. Early RA patients with anti-CFFCP1 antibodies, including CCP2-negative patients, show greater radiographic progression. 相似文献37.
An extra layer of complexity in the regulation of gene expression in bacteria is now apparent through previously unanticipated
roles of noncoding and antisense RNAs. 相似文献
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Yoshifumi Kotani Shoji Shinkai Hiroshi Okamatsu Masamichi Toba Kishiko Ogawa Hiroto Yoshida Taro Fukaya Yoshinori Fujiwara Paulo HM Chaves Keiji Kakumoto Noriyuki Kohda 《Immunity & ageing : I & A》2010,7(1):1-11
Background
Immunoglobulin A (IgA) secretion in saliva decreases with age and may be the cause of increased vulnerability of the elderly to respiratory infections. The effect of oral intake of lactic acid bacteria on salivary secretory IgA (SIgA) in the elderly has not been reported. The objective of this study was to demonstrate the acceleration of salivary SIgA secretion by oral intake of Lactobacillus pentosus strain b240 (b240) in the elderly.Results
A total of 80 healthy elderly individuals were randomly allocated to either an intervention (i.e., b240) or a control (i.e., placebo) group. The elderly individuals in the b240 group were given a sterile water beverage (125 mL) containing heat-killed b240 (4 × 109 cells), while those in the placebo group were given only a sterile water beverage (125 mL); both groups received their respective beverages once daily for 12 weeks. Saliva was collected before initiation of the study and every 2 weeks thereafter. Saliva flow rate and SIgA concentration were determined, and the SIgA secretion rate was calculated. The mean salivary SIgA secretion rate in the b240 group steadily increased until week 4 (exhibiting a 20% elevation relative to that at week 0), and then remained stable until week 12. Changes in SIgA secretion rate over the intervention period were significantly greater in the b240 group than in the placebo group. The treatment groups exhibited no significant differences in adverse events.Conclusions
Oral intake of L. pentosus strain b240 for 12 weeks significantly accelerated salivary SIgA secretion, thereby indicating its potential utility in the improvement of mucosal immunity and resistance against infection in the elderly. 相似文献40.
Lauber U Dillenburger T Schollenberger M Müller HM Drochner W 《Mycotoxin Research》2000,16(2):166-169
To examine the biotransformation of Deoxynivalenol (DON) by the normal gut flora of pigs (in reliance on toxin-source) an in-vitro system was established. Suspensions of rectum contents from different treated animals were incubated with pure DON. Despite fast adaptation of microflora (Deepoxidation of DON) of animals fed wheat diet, no effects on reduced feed consumption and weight gain were seen. Even fast adaptation of microflora (lower intestine) couldn’t avoid DON-effects in vivo. 相似文献