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1.
M. De Pirro G. Santini G. Chelazzi 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1999,169(7):501-506
Cardiac activity of two Mediterranean limpets was tested at different salinities. Patella caerulea inhabits the lower midlittoral where it is exposed to variations in salinity, while P. aspera experiences more stable salinity conditions in the infralittoral fringe. When exposed to moderate hypo- and hypersalinity
(23 g l−1 and 43 g l−1) for 24 min, P. caerulea showed no significant variation in heart rate with respect to the control salinity (33 g l−1), while P. aspera exhibited a significant increase in heart rate in both conditions. This suggests a rise in metabolic rate due to activation
of behavioural responses or physiological regulation. When exposed to extremely low salinity (3 g l−1) for 24 min, heart contractions ceased in most specimens of P. caerulea. A smaller number of specimens also displayed cessation of heart beat when exposed to extremely high salinity (63 g l−1). The heart beat resumed quickly in all specimens when they were returned to control salinity conditions. In contrast, cardiac
activity was not interrupted in any of the P. aspera specimens at the 3 g l−1 and 63 g l−1 salinity levels, but strong bradycardia was evident. Contractile activity of the heart ceased in all specimens of P. caerulea and P. aspera when they were exposed to prolonged hypo-osmotic stress (3 g l−1 for 24 h). This acardia was largely reversible in P. caerulea, but most specimens of P. aspera did not recover from the treatment.
Accepted: 3 July 1999 相似文献
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Intraspecific trait variability plays an important role in species adaptation to climate change. However, it still remains unclear how plants in semi-arid environments respond to increasing aridity. We investigated the intraspecific trait variability of two common Mediterranean annuals (Geropogon hybridus and Crupina crupinastrum) with similar habitat preferences. They were studied along a steep precipitation gradient in Israel similar to the maximum predicted precipitation changes in the eastern Mediterranean basin (i.e. −30% until 2100). We expected a shift from competitive ability to stress tolerance with decreasing precipitation and tested this expectation by measuring key functional traits (canopy and seed release height, specific leaf area, N- and P-leaf content, seed mass). Further, we evaluated generative bet-hedging strategies by different seed traits. Both species showed different responses along the precipitation gradient. C. crupinastrum exhibited only decreased plant height towards aridity, while G. hybridus showed strong trends of generative adaptation to aridity. Different seed trait indices suggest increased bet-hedging of G. hybridus in arid environments. However, no clear trends along the precipitation gradient were observed in leaf traits (specific leaf area and leaf N-/P-content) in both species. Moreover, variance decomposition revealed that most of the observed trait variation (≫50%) is found within populations. The findings of our study suggest that responses to increased aridity are highly species-specific and local environmental factors may have a stronger effect on intraspecific trait variation than shifts in annual precipitation. We therefore argue that trait-based analyses should focus on precipitation gradients that are comparable to predicted precipitation changes and compare precipitation effects to effects of local environmental factors. 相似文献
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Summary We have screened seven Spanish phenylketonuric (PKU) families for the most prevalent Mediterranean and Caucasian mutations, and have subsequently found mutations P281L and IVS10. We have analyzed these two mutations in 23 of our patients. The frequencies found correspond to those of Mediterranean countries, such as Italy. This is the first report of a mutation analysis in the Spanish PKU population. 相似文献
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Camci C Guney C Balkan A Buyukberber N Buyukberber S Kadayifci A Kubar A 《The new microbiologica》2002,25(4):463-468
Transfusion-transmitted virus (TTV) is a recently discovered transfusion-transmissible DNA virus. Its frequency and clinical impact has not been established in cancer patients in Turkey. In this study, we determined the prevalence of TTV DNA positivity, and its relationship with history of transfusion, amount of transfusion, age and sex in patients with hematological and solid malignancies. Sixty-one patients (35 male and 26 female) followed up for various malignancies and 45 healthy subjects were included in the study. ITV DNA was assayed by the polymerase chain reaction (PCR). TTV DNA was detected in 18 of 61 patients (29.5%) and in 5 of 45 control subjects (11.1%). In cancer patients, the prevalence of TTV DNA positivity was higher to comparison with control group. In addition, the prevalence of TTV DNA positivity was significantly higher in 22 patients who had a history of blood transfusion in the last 6 months than 39 patients who had no current or past history of transfusion (40.9% vs 23.0% respectively). These results suggest that the prevalence of TTV DNA is high and the parenteral route is an important mode of transmission for TTV in cancer patients. In addition, the high prevalence and persistence of TTV in cancer patients with parenteral risk exposure could be related to the immunodeficiency due to cancer and high viral loads by parenteral route. 相似文献
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Armstrong JW 《Journal of economic entomology》2001,94(1):302-314
Culled bananas (dwarf 'Brazilian', 'Grand Nain', 'Valery', and 'Williams') sampled from packing houses on the islands of Hawaii, Kauai, Maui, Molokai, and Oahu identified specific "faults" that were at risk from oriental fruit fly, Bactrocera dorsalis (Hendel), infestation. Faults at risk included bunches with precociously ripened bananas, or bananas with tip rot, fused fingers, or damage that compromised skin integrity to permit fruit fly oviposition into fruit flesh. No Mediterranean fruit fly, Ceratitis capitata (Wiedemann), or melon fly, B. cucurbitae (Coquillett), infestations were found in culled banana samples. Field infestation tests indicated that mature green bananas were not susceptible to fruit fly infestation for up to 1 wk past the scheduled harvest date when attached to the plant or within 24 h after harvest. Recommendations for exporting mature green bananas from Hawaii without risk of fruit fly infestation are provided. The research reported herein resulted in a USDA-APHIS protocol for exporting mature green bananas from Hawaii. 相似文献
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This study presents an analysis of temperature and precipitation trends and their impact on grape harvests in the Penedès region (NE Spain). It includes analyses of maximum, minimum and mean daily temperatures (for both the growing and ripening seasons) and daily rainfall (for the hydrological year, the growing season and each phenological stage) for three observatories in the immediate area. We analysed a series of factors: beginning and end harvest dates; the day on which a given potential alcoholic degree was reached; and yield for several varieties of grape grown in the area in relation to climatic variables. Maximum temperatures increased at all the observatories, with greater values being recorded in recent years (1996–2009) than in previous decades (1960s–2000s): we observed increases in average growing season temperatures of 0.11°C per year for the period 1996–2009 vs 0.04°C per year for the period 1960–2009 at Vilafranca del Penedès. These temperature changes were due mainly to increases in maximum temperatures and an increase in the incidence of extreme heat (number of days with T > 30°C). Crop evapotranspiration also increased significantly during the same period. The Winkler index also increased, so the study area would correspond to region IV according to that climatic classification. There were no significant trends in annual rainfall but rainfall recorded between bloom and veraison decreased significantly at the three observatories, with the greatest decrease corresponding to the period 1996–2009. The dates on which harvests started and ended showed a continuous advance (of between −0.7 and −1.1 days per year, depending on the variety), which was significantly correlated with the average mean and maximum daily growing season temperatures (up to −7.68 days for 1°C increase). Winegrape yield was influenced by the estimated water deficit (crop evapotranspiration minus precipitation) in the bloom-veraison period; this value increased due to a reduction in precipitation and an increase in evapotranspiration. Yield may have been reduced by up to 30 kg/ha for each millimetre increase in the estimated water deficit. Under these conditions, new strategies need to be followed in this area in order to maintain grape quality and yield. 相似文献
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Naoya Shinohara Takashi Owada Ami Tanaka Keiji Matsubayashi Tadashi Nagai Masahiro Satake 《Microbiology and immunology》2020,64(5):392-395
Hepatitis A virus (HAV) has begun to spread globally among men who have sex with men (MSM). Hepatitis E virus (HEV) also may be transmitted through sexual contact among MSM. To assess the current status of these viruses among MSM in Japan, the seroprevalence of both viruses using 503 plasma samples collected between 2009 and 2018 from human immunodeficiency virus (HIV)-positive male donors who were presumed to be mainly MSM was investigated. Our results suggested that HAV may be spreading within this population, as reported elsewhere. By contrast, the spread of HEV was confirmed only among younger HIV-positive donors. 相似文献
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Platelet count was 225 X 10(9)/l in 225 healthy male Algerians and 263 X 10(9)/l in 208 females. The mean platelet volume was 9.15 fl in the males and 9.30 in the females. The figures agree with those obtained in a British and an American population, but differed from those of an Australian population of immigrants from Mediterranean countries, essentially Italy and Greece. The prevalence of Mediterranean thrombocytopenia must therefore be low in Algeria. 相似文献
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Analysis of differently expressed proteins and transcripts in gills of Penaeus vannamei after yellow head virus infection 总被引:1,自引:0,他引:1
In this proteomic analysis of gills from yellow head virus (YHV)-infected Penaeus vannamei, we identified 13 spots with up-regulated protein expression levels and five spots with down-regulated levels. LC-nanoESI-MS/MS indicated that the up-regulated proteins included enzymes in the glycolytic pathway, the tricarboxylic acid cycle and amino acid metabolism. The other up-regulated proteins were arginine kinase, imaginal disk growth factor (IDGF) and a Ras-like GTP binding protein. By contrast, expression levels were reduced for an SCP-calcium binding protein (SCP), actin-1, a valosin-containing protein, and Rab11. Time-course assays by real time RT-PCR revealed no significant increase in mRNA level of glycolytic enzymes and arginine kinase. However, a significant decrease in SCP mRNA was observed. The present results are consistent with previously published work and suggest that a decrease in SCP expression may play an important role in the shrimp response to viral infections in general. 相似文献
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Fedele G Nasso M Spensieri F Palazzo R Frasca L Watanabe M Ausiello CM 《Journal of immunology (Baltimore, Md. : 1950)》2008,181(1):208-216
Bordetella pertussis and B. parapertussis are the etiological agents of pertussis, yet the former has a higher incidence and is the cause of a more severe disease, in part due to pertussis toxin. To identify other factors contributing to the different pathogenicity of the two species, we analyzed the capacity of structurally different lipooligosaccharide (LOS) from B. pertussis and LPS from B. parapertussis to influence immune functions regulated by dendritic cells. Either B. pertussis LOS and B. parapertussis LPS triggered TLR4 signaling and induced phenotypic maturation and IL-10, IL-12p40, IL-23, IL-6, and IL-1beta production in human monocyte-derived dendritic cells (MDDC). B. parapertussis LPS was a stronger inducer of all these activities as compared with B. pertussis LOS, with the notable exception of IL-1beta, which was equally produced. Only B. parapertussis LPS was able to induce IL-27 expression. In addition, although MDDC activation induced by B. parapertussis LPS was greatly dependent on soluble CD14, B. pertussis LOS activity was CD14-independent. The analysis of the intracellular pathways showed that B. parapertussis LPS and B. pertussis LOS equally induced IkappaBalpha and p38 MAPK phosphorylation, but B. pertussis LOS triggered ERK1/2 phosphorylation more rapidly and at higher levels than B. parapertussis LPS. Furthermore, B. pertussis LOS was unable to induce MyD88-independent gene induction, which was instead activated by B. parapertussis LPS, witnessed by STAT1 phosphorylation and induction of the IFN-dependent genes, IFN regulatory factor-1 and IFN-inducible protein-10. These differences resulted in a divergent regulation of Th cell responses, B. pertussis LOS MDDC driving a predominant Th17 polarization. Overall, the data observed reflect the different structure of the two LPS and the higher Th17 response induced by B. pertussis LOS may contribute to the severity of pertussis in humans. 相似文献
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We report results of a project aimed at analysing genetic diversification in Lepus corsicanus (italian hare), carried out at the INFS as part of an ongoing project on the biology of L. corsicanus. Samples of Italian hare were collected in different localities in central-southern Italy and Sicily. Moreover samples of L. europaeus (brown hare), as well as other species of the genus Lepus, were collected in Italy and Europe in order to define the phylogenetic relationships of the Italian hare. Results show a clear genetic distinction of the Italian hare. Consequently the status of true species is warranted at the molecular level. Phylogenetic relationships among species suggest the presence of two distinct groups, the Italian hare belonging to an evolutionary lineage including species which probably originated in a glacial refugia in southern Europe before colonization by the brown hare. On the other hand the brown hare belongs to a different lineage including species of African origins. 相似文献
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ABSTRACT Snowshoe hares (Lepus americanus) are an important prey species for Canada lynx (Lynx canadensis) and are considered critical for lynx population persistence. Determination of snowshoe hare distribution and abundance is needed by land management agencies for lynx conservation. An accepted approach for estimating snowshoe hare abundance is the use of fecal-pellet plot counts. Locally derived regression equations are preferred for accurate calibration of pellet counts to snowshoe hare density due to local differences in pellet deposition and decomposition. We used linear regression to examine correlations between snowshoe hare density, as determined by mark–recapture estimates, and pellet plot counts on both uncleared plots and annually cleared plots on the Bridger-Teton National Forest, western Wyoming, USA. We found significant correlations between snowshoe hare density estimates and fecal pellet counts for both uncleared and annually cleared pellet counts; however, the relationship was stronger (higher r) when using pellet counts from annually cleared plots. In addition, we found that adjusting the buffer size by omitting hard habitat edges (not used by hares) around trapping grids improved correlations between snowshoe hare density and fecal pellet counts for both uncleared plots and annually cleared plots. Though precision is sacrificed when using uncleared plots, they may be useful as a coarse index of habitat use by snowshoe hares. Our derived regression equations may be useful to identify important foraging habitat for Canada lynx in western Wyoming. Land managers responsible for conserving snowshoe hare habitat in western Wyoming may use these equations to monitor changes in hare populations among habitats and during prescribed management actions. 相似文献
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J Taylor-Wiedeman K Yamashita K Miyamura S Yamazaki 《Japanese journal of medical science & biology》1989,42(1):1-11
A seroepidemiologic time-comparison study was conducted to evaluate changes in IgG antibody to varicella-zoster virus (VZV) and to determine VZV prevalence in Japan with randomly collected serum samples from two healthy Japanese populations: 1973 (n = 670) vs. 1984 (n = 677). Enzyme-linked immunosorbent assay (ELISA) was found to be superior to the immune adherence hemagglutination test (IAHA) especially for detecting seropositivity in adults. Serologic results showed essentially no significant difference between the 1973 and the 1984 age-specific prevalences; with the exception of a slightly lower prevalence in the 5-year-old age group in 1973 than that in 1984. In general, the age-specific prevalence was lowest in the 1-year-old group (mean 11%) and increased in a linear fashion until age 9 (mean 82.9%); prevalence continued to increase slowly after age 9 and plateaued at 100% for ages greater than or equal to 25-29. 相似文献
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L Dunford MJ Carr J Dean A Waters LT Nguyen TH Ta Thi LA Thi HD Do TT Thi HT Nguyen TT Diem Do QP Luu J Connell S Coughlan HT Nguyen WW Hall LA Nguyen Thi 《PloS one》2012,7(8):e41266
Hepatitis C virus (HCV) is a genetically diverse pathogen infecting approximately 2–3% of the world''s population. Herein, we describe results of a large, multicentre serological and molecular epidemiological study cataloguing the prevalence and genetic diversity of HCV in five regions of Vietnam; Ha Noi, Hai Phong, Da Nang, Khanh Hoa and Can Tho. Individuals (n = 8654) with varying risk factors for infection were analysed for the presence of HCV Ab/Ag and, in a subset of positive specimens, for HCV RNA levels (n = 475) and genotype (n = 282). In lower risk individuals, including voluntary blood donors, military recruits and pregnant women, the prevalence of infection was 0.5% (n = 26/5250). Prevalence rates were significantly higher (p<0.001) in intravenous drug users (IDUs; 55.6%, n = 556/1000), dialysis patients (26.6%, n = 153/575) commercial sex workers (CSWs; 8.7%, n = 87/1000), and recipients of multiple blood transfusions (6.0%, n = 32/529). The prevalence of HCV in dialysis patients varied but remained high in all regions (11–43%) and was associated with the receipt of blood transfusions [OR: 2.08 (1.85–2.34), p = 0.001], time from first transfusion [OR: 1.07 (1.01–1.13), p = 0.023], duration of dialysis [OR: 1.31 (1.19–1.43), p<0.001] and male gender [OR: 1.60 (1.06–2.41), p = 0.026]. Phylogenetic analysis revealed high genetic diversity, particularly amongst dialysis and multi-transfused patients, identifying subtypes 1a (33%), 1b (27%), 2a (0.4%), 3a (0.7%), 3b (1.1%), 6a (18.8%), 6e (6.0%), 6h (4.6%), 6l (6.4%) and 2 clusters of novel genotype 6 variants (2.1%). HCV genotype 1 predominated in Vietnam (60%, n = 169/282) but the proportion of infections attributable to genotype 1 varied between regions and risk groups and, in the Southern part of Vietnam, genotype 6 viruses dominated in dialysis and multi-transfused patients (73.9%). This study confirms a high prevalence of HCV infection in Vietnamese IDUs and, notably, reveals high levels of HCV infection associated with dialysis and blood transfusion. 相似文献
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Zehender G Ebranati E Gabanelli E Shkjezi R Lai A Sorrentino C Lo Presti A Basho M Bruno R Tanzi E Bino S Ciccozzi M Galli M 《PloS one》2012,7(5):e37198
Hepatitis B virus genotype D can be found in many parts of the world and is the most prevalent strain in south-eastern Europe, the Mediterranean Basin, the Middle East, and the Indian sub-continent. The epidemiological history of the D genotype and its subgenotypes is still obscure because of the scarcity of appropriate studies. We retrieved from public databases a total of 312 gene P sequences of HBV genotype D isolated in various countries throughout the world, and reconstructed the spatio-temporal evolutionary dynamics of the HBV-D epidemic using a bayesian framework.The phylogeographical analysis showed that India had the highest posterior probability of being the location of the tree root, whereas central Asia was the most probable location of the common ancestor of subgenotypes D1-D3. HBV-D5 (identified in native Indian populations) diverged from the tree root earlier than D1-D3. The time of the most recent common ancestor (tMRCA) of the tree root was 128 years ago, which suggests that the common ancestor of the currently circulating subgenotypes existed in the second half of the XIX century. The mean tMRCA of subgenotypes D1-D3 was between the 1940s and the 1950-60s. On the basis of our phylogeographic reconstruction, it seems that HBV-D reached the Mediterranean area in the middle of the XX century by means of at least two routes: the first pathway (mainly due to the spread of subgenotype D1) crossing the Middle East and reaching north Africa and the eastern Mediterranean, and the second pathway (closely associated with D2) that crossed the former Soviet Union and reached eastern Europe and the Mediterranean through Albania. We hypothesise that the main route of dispersion of genotype D was the unsafe use of injections and drug addiction. 相似文献