Many mountain pastures consist of a mosaic of grassland and shrub communities. Ongoing changes in mountain agriculture have affected the balance between the two elements of the mosaic. In order to ...understand the consequences of these changes for ecosystem functioning, we studied patterns in vegetation, root structure and soil properties along transects of varying grassland-to-shrub proportions. Our hypothesis was that differences in the vegetation aboveground are accompanied by differences belowground, related to soil properties and depth. The research was conducted at a subalpine site in the Trentino region (South-eastern Alps), consisting of Nardus stricta grasslands alternating with shrub patches of Rhododendron ferrugineum. Our investigation showed that the composition of vegetation was mainly governed by R. ferrugineum cover and less by soil properties. Plant species richness peaked at low to intermediate degrees of shrub cover and composition between transects became more similar with increasing shrub cover. Where R. ferrugineum cover was higher, Hemicryptophytes caespitosae were replaced by Nano-phanerophytes with consequences for belowground structures. At increasing shrub cover, root length density decreased, especially in the top soil, while root weight density remained stable and C content increased insignificantly. We discuss that theses structural changes along the gradient of R. ferrugineum cover affect a number of ecosystem services. The presented evidence suggests that maintaining grasslands with a low cover of R. ferrugineum balances a number of services, namely plant species diversity, carbon stabilization in soil and the prevention of soil erosion.
The positive effects of trinexapac-ethyl (TE) on turfgrass growth and tolerance to various types of stress could promote its use in low-input maintenance turfgrasses to reduce the expense associated ...with mowing. However, there is a general lack of information about TE effects in low maintenance turfgrasses, and especially when used in transition zone turfgrass mixtures. The objective of this study was to evaluate the response of three inter-specific turfgrass mixtures to three different application rates of TE under low maintenance conditions.
A 2-year field study was conducted from April 2006 to July 2008 at the Agricultural Experimental Farm of the University of Padova (northern Italy, 45°20′N, 11°57′E, elevation 8 m). Visual turfgrass quality (1–9 scale) and clippings biomass production of three mixtures were evaluated seasonally under four TE treatments with rates representing 0, 0.5, 1.0 or 1.5x the rates indicated on label instructions. Based on both visual quality and biomass production, turfgrass responded differently to TE application depending on dominant species in the mixture. Furthermore, our results suggested that changes over time in turfgrass botanical composition influence visual quality and biomass production through the experimental period. The main effect of TE treatments occurred in biomass production while the effect on turfgrass quality was mainly associated with the two highest TE rates. Application at a rate lower than the labeled seems to be enough for reducing biomass production without affecting turfgrass quality or even, in some seasons, improving it. Finally, we found that the effect of TE seems to weaken over time as turfgrass maturity advances.
•There is few information about Trinexapac-ethyl use in low-input turfgrass mixtures.•Trinexapac-ethyl effect depends on dominant species in the mixture.•Trinexapac-ethyl affects biomass production more than visual quality.•Half the labeled rate is enough for reducing biomass production.
Posttransfusion positive dipsticks for occult blood do not differentiate hemoglobinuria from myoglobinuria, relatively common events in infants admitted to the neonatal intensive care unit. We ...studied posttransfusion plasma and urine hemoglobin and myoglobin in relation to occult blood positivity in the urine dipsticks, in 48 consecutive transfusions with packed RBC (28 neonates, birth weight 850-3,700 g, postnatal age 3-167 days). Urine dipsticks show a low sensitivity for detecting hemoglobin and also undervalue myoglobin, both possible in different amounts in the plasma and urine of ill neonates. However, posttransfusion occult blood positive urine dipsticks due to myoglobinuria are present in 10% of transfused neonates.
IgM antibody to hepatitis B core antigen (anti-HBc IgM) was investigated by an antibody-capture radioimmunoassay (serum dilution 1:4000) in serum samples from 31 untreated children with chronic ...hepatitis B who were followed prospectively for 1-7 years. At the start, all patients were positive for hepatitis B e antigen (HBeAg), and anti-HBc IgM was detected in 23 cases, including 15 out of 16 with chronic active hepatitis and 7 out of 14 with chronic persistent hepatitis. A significant positive correlation was found between anti-HBc IgM levels and severity of liver damage (P less than 0.05), while an inverse relationship was found between anti-HBc IgM levels and distribution of hepatitis B core (HBcAg) antigen in the liver as detected by immunofluorescence. In fact 75% of anti-HBc IgM positive patients showed a focal HBcAg pattern (less than 40% positive nuclei), whereas 87% of antibody negative cases exhibited a diffuse HBcAg expression (more than 60% stained nuclei). During follow-up, seroconversion from HBeAg to anti-HBe with subsequent remission of liver disease occurred in 82% of patients presenting with detectable levels of anti-HBc, including three out of seven cases with chronic persistent hepatitis, but in none of the cases that were initially negative (P less than 0.01). These results indicate that during the natural course of chronic hepatitis B in children, anti-HBc IgM levels in serum reflect the degree of host immune response to infected hepatocytes. The close correlation between anti-HBc IgM seropositivity and seroconversion from HBeAg to anti-HBe suggests that anti HBc IgM may have a prognostic value during the follow-up of children with chronic HBeAg positive hepatitis B.
The epidemiological features of acute symptomatic viral hepatitis were examined in 151 consecutive, hospitalized drug abusers. Hepatitis B was diagnosed in 101 patients (66.8%), hepatitis A in 13 ...(8.6%) and non-A, non-B hepatitis in 35 (23.1%). Non-A, non-B hepatitis was significantly more prevalent among drug abusers than in an age-matched control population of non-drug abusers. Moreover, the mean duration of parenteral drug abuse was significantly lower among non-A, non-B cases than in patients with hepatitis A or B. These results suggest a wide circulation of both hepatitis B virus and non-A, non-B agent(s) among drug abusers in our area. These patients most likely represent a main reservoir of non-A, non-B infection due to the high rate of chronicity reported for non-A, non-B hepatitis.
A 1-year follow-up study of the T-cell subset abnormalities was carried out in 16 severe haemophilia A patients, treated "on demand" with an average amount of 500 U/kg/yr of factor VIII concentrate ...(group A) and in 15 mild haemophiliacs or von Willebrand patients treated only sporadically with less than 3000 U of factor VIII and no longer exposed to any other blood component in the 2 years preceding the beginning of the study (group B). In group A, 50% and 70% of patients showed a reduced or inverted T 4/T 8 ratio, respectively, at the beginning and at the end of follow-up. These values were of 30% and 20% in patients of group B, suggesting a long-lasting effect of concentrate therapy on T-cell subsets. The low T 4/T 8 ratio was mainly due to an increase of suppressor cells. None of the patients was found positive for anti HTLV-I, whereas 3 patients, all belonging to the group A, showed antibodies against HTLV-III. Thus, in these patients, HTLV-III seems not to be the only cause of low T 4/T 8 ratio.
8 children, known to have been hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) positive for more than 6 months and with chronic active hepatitis on biopsy, received 2.5 mg ...levamisole/kg/day, 2 days a week for 6-18 months. In 6 of the 8 children transaminases normalized within 4-18 months of therapy, with seroconversion to antibody to HBeAg (anti-HBe) and disappearance of HBV-DNA polymerase from serum and of hepatitis B core antigen (HBcAg) from liver. In these cases liver biopsies taken after treatment showed histological regression to chronic persistent hepatitis. Two distinct patterns of response to levamisole were noted: patients having higher pretreatment transaminase levels and lower expression of HBcAg in the liver showed an early transaminase normalization and anti-HBe seroconversion with therapy, while in patients with less active disease and more diffuse HBcAg positivity in pretreatment liver biopsies, longer treatment periods were necessary to achieve these effects. Our results suggest that long-term levamisole therapy may be beneficial in HBeAg-positive chronic hepatitis type B.
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