Linking Foliar Chemistry to Forest Floor Solid and Solution Phase Organic C and N in Picea abies [L.] Karst Stands in Northern Bohemia

Dissolved organic carbon and nitrogen (DOC and DON) produced in the forest floor are important for ecosystem functions such as microbial metabolism, pedogenesis and pollutant transport. Past work has shown that both DOC and DON production are related to litterfall and standing stocks of C and N in the forest floor. This study, conducted in spring, 2003, investigated variation in forest floor water extractable DOC (WEDOC) and DON (WEDON) and forest floor C and N as a function of lignin, cellulose and N contained in live canopy foliage across eight Picea abies [L.] Karst stands in northern Bohemia. Based on Near Infrared Spectroscopy (NIR) analysis of foliar materials, lignin:N and cellulose:N content of the youngest needles (those produced in 2002) were positively and significantly related to WEDOC (R² = 0.82–0.97; P<0.01) and to forest floor C:N ratio (R = 0.72–0.78; P<0.01). Foliar N was strongly and negatively related to WEDOC and C:N ratio (R = −0.91 and 0.72; P<0.05) among our study sites. WEDON was positively correlated to foliar lignin:N (R = 0.48; P<0.05; n=40). Forest floor C pools were not positively correlated with foliar lignin and cellulose and forest floor N pools were not positively correlated with foliar N. Instead, a significant negative correlation was found between forest floor N pools and foliar cellulose (R=−0.41; P<0.05), and between forest floor C pools and foliar N (R = −0.44; P<0.05). From a remote sensing standpoint, our results are important because canopy reflectance properties are primarily influenced by the most recent foliage, and it was the chemistry of the most recently produced needles that showed a stronger relationship with forest floor WEDOC and C:N ratio suggesting forest floor production of WEDOC can be calculated regionally with remote sensing.     

Tiotropium Respimat? in asthma: a double-blind,randomised, dose-ranging study in adult patients with moderate asthma

Background

Tiotropium, a once-daily long-acting anticholinergic bronchodilator, when administered via Respimat® SoftMist™ inhaler (tiotropium Respimat®) significantly reduces the risk of severe exacerbations and improves lung function in patients with severe persistent asthma that is not fully controlled despite using inhaled corticosteroids (ICS) and long-acting β₂-agonists. To further explore the dose–response curve in asthma, we investigated the efficacy and safety of three different doses of tiotropium Respimat® as add-on to ICS in symptomatic patients with moderate persistent asthma.

Methods

In this randomised, double-blind, placebo-controlled, four-way crossover study, patients were randomised to tiotropium Respimat® 5 μg, 2.5 μg or 1.25 μg or placebo Respimat®, once daily in the evening. Each treatment was administered for 4 weeks, without washout between treatment periods. Eligibility criteria included ≥60% and ≤90% of predicted normal forced expiratory volume in 1 second (FEV₁) and seven-question Asthma Control Questionnaire mean score of ≥1.5. Patients were required to continue maintenance treatment with stable medium-dose ICS for at least 4 weeks prior to and during the treatment period. Long-acting β₂-agonists were not permitted during the treatment phase. The primary efficacy end point was peak FEV₁ measured within 3 hours after dosing (peak FEV_1(0-3h)) at the end of each 4-week period, analysed as a response (change from study baseline).

Results

In total, 149 patients were randomised and 141 completed the study. Statistically significant improvements in peak FEV_1(0-3h) response were observed with each tiotropium Respimat® dose versus placebo (all P < 0.0001). The largest difference from placebo was with tiotropium Respimat® 5 μg (188 mL). Trough FEV₁ and FEV₁ area under the curve (AUC)_(0-3h) responses were greater with each tiotropium Respimat® dose than with placebo (all P < 0.0001), and both were greatest with 5 μg. Peak forced vital capacity (FVC)_(0-3h), trough FVC and FVC AUC_(0-3h) responses, versus placebo, were greatest with tiotropium Respimat® 5 μg (P < 0.0001, P = 0.0012 and P < 0.0001, respectively). Incidence of adverse events was comparable between placebo and all tiotropium Respimat® groups.

Conclusions

Once-daily tiotropium Respimat® add-on to medium-dose ICS improves lung function in symptomatic patients with moderate asthma. Overall, improvements were largest with tiotropium Respimat® 5 μg.

Trial registration

ClinicalTrials.gov identifier {"type":"clinical-trial","attrs":{"text":"NCT01233284","term_id":"NCT01233284"}}NCT01233284.     

Occurrence of bifidobacteria in faeces of calves fed milk or a combined diet

The development of faecal bacteria composition in calves fed milk or a combined diet was investigated from 4 to 21 days of age. On day 7, bifidobacteria in faeces of milk-fed calves already increased from about 7.6 to 9.2 log CFU/g and did not change until the end of the study, whereas in calves fed the combined diet bifidobacteria only moderately increased to 7.9 log CFU/g and decreased slowly until day 21. The counts of bifidobacteria in calves on a combined diet were significantly (p < 0.01) lower compared to those in milk-fed calves. Bifidobacterial counts determined by cultivation or by fluorescence in situ hybridisation (FISH) did not differ significantly. Our results showed that the occurrence of bifidobacteria in calf faeces is highly dependent on the diet composition. Faecal bacteria flora of calves fed exclusively by milk is rich in bifidobacteria, but in calves on a combined diet coliforms dominated.     

Molecular Detection of Murine Herpesvirus 68 in Ticks Feeding on Free-living Reptiles

The MHV-68 (designed as Murid herpesvirus 4 (MuHV 4) strain 68) isolated from two rodents, Myodes glareolus and Apodemus flavicollis, is considered as a natural pathogen of free-living murid rodents. Recently, the detection of MHV antibodies in the blood of animals living in the same biotope as MHV-infected mice has suggested that ticks may have a role in the transmission of this pathogen. Ixodes ricinus is one the most abundant tick species in Europe known to transmit multiple pathogens causing human and animal diseases. In this study, nymphs and larvae feeding on 116 individuals of a temperate lizard species—the green lizard Lacerta viridis captured in the Slovak Karst National Park, were examined for MHV-68. The specific sequence of virion glycoprotein 150 was amplified in DNA individually isolated from I. ricinus ticks using single-copy sensitive nested polymerase chain reaction. MHV-68 was detected in ten of 649 nymphs and in five of 150 larvae, respectively. We found that 9.6% of green lizards fed at least one MHV-68-infected immature tick. Occurrence of MHV-68 within all ticks tested was 1.8%. This study is first to show that immature I. ricinus ticks feeding on free-living lizards in a Central European region could be infected with gammaherpesvirus (MHV-68), naturally infecting free-living murid rodents. Our results provide evidence supporting the hypothesis that ticks may play a mediating role in circulation of MHV-68 in nature.     

Long-term changes in numbers and distribution of wintering waterbirds in the Czech Republic, 1966–2008

Capsule?Of 26 species of wintering waterbirds, 18 showed an increase in numbers, five showed a decrease and two showed no change.

Aim?To assess long-term trends in the numbers and distribution of the 26 most abundant wintering waterbird species in the Czech Republic.

Methods?We used International Waterbird Census data from between 48 and 639 wetland sites which had been counted annually in the Czech Republic from 1966 to 2008. From these data long-term changes in numbers and distributions were determined. Log-linear Poisson regression analysis was used to estimate missing data using trim software. The distribution of each species was described as the ratio of the number of sites occupied by that species to the total number of sites investigated.

Results?Increasing trends were found for 18 species, five species were found to be declining, one species was stable and two species were found with uncertain trends. Wintering distributions (the ratio of sites occupied by a given species to the total number of sites counted) increased in 16 species and decreased in two species, broadly correlated with the species changes in numbers.

Conclusion?In most species changes in numbers as well as changes in distribution followed the Western Palearctic population trends. Those species which increased were mainly piscivores and included geese, ducks and gulls. Scarcer species also exhibited an increase in numbers. The changes in numbers (both positive and negative) were more frequent among species associated with running water, whereas species which showed uncertain trends were more frequently recorded on standing water, which is more affected by variable weather conditions.     

Diversity,distribution and host-species associations of epiphytic orchids in Nepal

Associations between epiphytes and their hosts are among the main factors affecting the biodiversity and distribution of epiphytes. While several previous studies explored the association between epiphyte diversity and host characteristics, very little is known about the generality of such associations at larger spatial scales. We aim to explore the associations between diversity and distribution of epiphytic orchids and host characteristics in different localities in Nepal. Epiphytic orchids and their hosts were recorded along the transects in total of 23,539 host individuals. To describe the diversity of orchids in the different localities, a rarefaction function was used. Univariate and multivariate analyses were carried out to explore the associations with locality, host characteristics, and their interactions with locality. In total, we recorded 141 species of orchids growing on 192 host species. The five localities significantly differed in orchid diversity and abundance. The number of orchid individuals per host species significantly increased with increasing number of host individuals. Species richness, abundances, occupancy of orchid species on host species and composition of orchids varied across the localities. Species richness and abundance was significantly higher on hosts in the higher strata and differed between families of host species. Abundance was higher on evergreen hosts. Composition of orchid communities are also associated with host characteristics, such as habit (shrub/tree/climber), bark texture, nature (deciduous/evergreen) and the plant families of host species. This study revealed a high diversity of epiphytic orchids in the localities studied and strong associations between the orchids and their hosts. Future studies looking at the relationships between epiphyte communities and host characteristics need to identify relationships at a wider scale in order to determine whether they are really general rather than site-specific.     

ANG II type 1 receptor antagonist irbesartan inhibits coronary angiogenesis stimulated by chronic intermittent hypoxia in neonatal rats

Chronic hypoxia has been shown to stimulate myocardial microvascular growth and improve cardiac ischemic tolerance in young and adult rats. The aim of this study was to determine whether the ANG II type 1 receptor (AT(1)) pathway was involved in these processes. Newborn Wistar rats, exposed to chronic intermittent hypoxia (8 h/day) for 10 days, were simultaneously treated with AT(1) receptor blocker irbesartan and compared with untreated animals. The major finding is that chronic hypoxia increased the capillary supply of myocardial tissue, which was even more pronounced in hypertrophied right ventricle, whereas increased arteriolar supply was found only in the left ventricle. This angiogenic response was completely prevented by irbesartan. Moreover, chronic hypoxia improved the postischemic recovery of cardiac contractile function during reperfusion, and this protective effect was also completely abolished by irbesartan. Chronic hypoxia increased the myocardial density of AT(1) but not of ANG II type 2 receptor subtypes, whereas the effect of irbesartan was not significant. The expression of caveolin-1alpha markedly increased in response to chronic hypoxia, and irbesartan prevented this effect. Neither hypoxia nor irbesartan treatment altered the expression of nitric oxide synthase 3, heat shock protein 90, and VEGF. It is concluded that the AT(1) receptor pathway plays an important role in coronary angiogenesis and improved cardiac ischemic tolerance induced in neonatal rats by chronic hypoxia.