Source or decomposition of soil organic matter: what is more important with increasing forest age in a subalpine setting?

Afforestation has been the dominant land-use change in the Swiss Alps during the last decades which has not only the potential to increase soil organic carbon sequestration, but it has also the potential to alter soil organic matter (SOM) dynamics through the vegetation shift and change in organic matter (OM) input into soils. The effects of afforestation on SOM dynamics, however, are still not fully understood as specific sources of OM and modifications of soil processes influencing decomposition and preservation remain largely unknown on alpine to subalpine slopes. Within this study we aimed to identify the potential sources and the decomposition of OM in a subalpine afforestation chrono-sequence (0–130 years) with Norway spruce (Picea abies L.) on a former pasture by using a multi-proxy molecular marker approach. We observed that leaf-derived OM plays an essential role in the pasture areas, while root-derived OM only plays a minor role in pasture and forest areas. Needle-derived OM represents the dominant source of SOM with increasing forest age, while understory shrubs and moss also contribute to the OM input in younger forest stand ages. However, needle litter and buildup of organic layers and subsequently less input of fresh OM from organic horizons to mineral soil can result in increased OM decomposition in mineral soils rather than contributing to additional SOM stabilization in mineral soils. This was most pronounced in the oldest forest stand (130-year-old) in the investigated afforestation sequence, particularly in deeper soil horizons (10–45 cm). Thereby, our study provides new insights into SOM dynamics following afforestation, especially with respect to the long-term SOM sequestration potential of afforestation of subalpine pasture soils

The G protein-coupled receptor subset of the dog genome is more similar to that in humans than rodents

<p>Abstract</p> <p>Background</p> <p>The dog is an important model organism and it is considered to be closer to humans than rodents regarding metabolism and responses to drugs. The close relationship between humans and dogs over many centuries has lead to the diversity of the canine species, important genetic discoveries and an appreciation of the effects of old age in another species. The superfamily of G protein-coupled receptors (GPCRs) is one of the largest gene families in most mammals and the most exploited in terms of drug discovery. An accurate comparison of the GPCR repertoires in dog and human is valuable for the prediction of functional similarities and differences between the species.</p> <p>Results</p> <p>We searched the dog genome for non-olfactory GPCRs and obtained 353 full-length GPCR gene sequences, 18 incomplete sequences and 13 pseudogenes. We established relationships between human, dog, rat and mouse GPCRs resolving orthologous pairs and species-specific duplicates. We found that 12 dog GPCR genes are missing in humans while 24 human GPCR genes are not part of the dog GPCR repertoire. There is a higher number of orthologous pairs between dog and human that are conserved as compared with either mouse or rat. In almost all cases the differences observed between the dog and human genomes coincide with other variations in the rodent species. Several GPCR gene expansions characteristic for rodents are not found in dog.</p> <p>Conclusion</p> <p>The repertoire of dog non-olfactory GPCRs is more similar to the repertoire in humans as compared with the one in rodents. The comparison of the dog, human and rodent repertoires revealed several examples of species-specific gene duplications and deletions. This information is useful in the selection of model organisms for pharmacological experiments.</p

Electric double layer and electrokinetic potential of pectic macromolecules in sugar beet

Electrokinetic potential is an important property of colloidal particles and, regarding the fact that it is a well defined and easily measurable property, it is considered to be a permanent characteristic of a particular colloidal system. In fact, it is a measure of electrokinetic charge that surrounds the colloidal particle in a solution and is in direct proportion with the mobility of particles in an electric field. Gouy-Chapman-Stern-Graham's model of electric double layer was adopted and it was proven experimentally that the addition of Cu++ ions to sugar beet pectin caused a reduction in the negative electrokinetic potential proportional to the increase of Cu++ concentration. Higher Cu++ concentrations increased the proportion of cation specific adsorption (Cu++ and H+) with regard to electrostatic Coulombic forces. Consequently, there is a shift in the shear plane between the fixed and diffuse layers directed towards the diffuse layer, i.e. towards its compression and decrease in the electrokinetic potential or even charge inversion of pectin macromolecules

Comments on the article Opial inequality in q-Calculus

We give corrections concerned with the proofs of the theorems from the paper Opial inequality in q-Calculus, where integral inequalities of the q-Opial type were established

Spent carbide waste retains toxicity long term after disposal in caves and mines

We studied the environmental impact of wastes derived from calcium carbide, which is widely used for generating acetylene in industry and speleology. It was shown that spent carbide is toxic for biota and harmful to cave ecosystems and the surrounding environment. The toxic components of spent carbide waste were found to include calcium hydroxide, strontium and polycyclic aromatic hydrocarbons. The 50% lethal doses (LD 50%) of fresh spent carbide waste were calculated as 0.28-0.32 g/l in biotests with daphnia, infusoria, and fishes. The toxicity of spent carbide declined only slowly over time, with toxicity still present in 13-year-old samples. Spent carbide should be disposed of with great care to ensure that it cannot be disseminated into natural water systems. Spent carbide deactivation could be provided within isolated bowls filled with water (micro sediment bowls) or within water-proof storage containers, and complete recycling could be achieved through the addition of deactivated waste to solid building materials.Keywords: carbide, cave, mine, waste, toxicity, impact

Dynamic susceptibility contrast enhanced (DSC) MRI perfusion and plasma cytokine levels in patients after tonic-clonic seizures

Background Inflammatory events in brain parenchyma and glial tissue are involved in epileptogenesis. Blood concentration of cytokines is shown to be elevated after tonic-clonic seizures. As a result of inflammation, blood-brain barrier leakage occurs. This can be documented by imaging techniques, such is dynamic susceptibility contrast enhanced (DSC) MRI perfusion. Our aim was to check for postictal brain inflammation by studying DSC MRI perfusion and plasma level of cytokines. We looked for correlations between number and type of introducing seizures, postictal plasma level of cytokines and parameters of DSC MRI perfusion. Furthermore, we looked for correlation of those parameters and course of the disease over one year follow up. Patients and methods We prospectively enrolled 30 patients, 8%24 hours after single or repeated tonic-clonic seizures. Results 25 of them had normal perfusion parameters, while 5 had hyperperfusion. Patients with hyperperfusion were tested again, 3 months later. Two of 5 had hyperperfusion also on control measurements. Number of index seizures negatively correlated with concentration of proinflammatory cytokines IL-10, IFN-[gamma] and TNF-[alpha] in a whole cohort. In patients with hyperperfusion, there were significantly lower concentrations of antiinflammatory cytokine IL-4 and higher concentrations of proinflammatory TNF-[alpha]. Conclusions Long lasting blood- brain barrier disruption may be crucial for epileptogenesis in selected patients

Reversible lymphomagenesis in conditionally c-MYC expressing mice

It is well documented that deregulation of MYC leads to tumor development, yet many aspects of this process are only partially understood. We have established a transgenic mouse model in which c-MYC is conditionally expressed in lymphoid cells using the tetracycline-regulated system of gene regulation. Mice with continuously expressed transgenic c-MYC died of invasive T- or B-cell lymphomas within 4 months. Lymphomas developing in transgenic mice were c-MYC dependent since doxycycline treatment led to tumor regression. Using transplantation of established tumor cell lines labeled with GFP, we followed the fate of neoplastic cells in recipients upon MYC inactivation. This approach allowed us to elucidate both apoptosis and differentiation as mechanisms of tumor elimination. Comparative genomic hybridization (CGH) and FISH analyses were performed in order to analyze possible chromosomal aberrations induced by c-MYC. We observed that overexpression of c-MYC is sufficient to induce recurrent patterns of genomic instability. The main observation was a gain of genomic material that corresponded to chromosome 15 in several T-cell tumors, which could be identified as trisomy

Phase evolution of Si3N4 with Mg-exchanged zeolite additive

This paper deals with the chemical reactions and phase evolution during pressureless sintering of Si3N4 with Mg-exchanged zeolite as sintering additive. The XRD data show that the first MgO-rich liquid forms at as low as 1250 °C, which as a consequence results in a significant reduction of sintering temperature. At 1300 °C the β−Si3N4 phase had disappeared indicating its dissolution into the liquid phase. At 1500 °C the secondary phase had been completely converted into a glassy phase, however, no phase transformation from α−Si3N4 to β−Si3N4 had taken place. Thus the composition of this material consists of α−Si3N4 embedded in magnesium silicon oxynitride glassy phase.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

Funkcije bubrega u rudara intermitentno izloženih parama elementarne žive

The authors investigated renal damage in 45 mercury miners under conditions of relatively short and low-level exposure to elemental (metallic) mercury vapour (Hg0). The analysis included urinary mercury, immunoelectrophoresis of urinary proteins, immunofixation and high-resolution electrophoresis, quantitative analysis of urinary albumin, and urinary a1-microglobulin before and after exposure. The activity of urinary N-acetyl-b- D-glucosaminidase (NAG) enzyme was determined after exposure. The average duration of exposure of miners was 37 (6–82) days. Urinary mercury significantly increased during exposure. Immunoelectrophoretic changes in the composition of urinary proteins occurred after exposure in 22 of 45 miners, of whom 15 showed high molecular weight (HMW) pattern of urinary proteins and seven showed low molecular weight (LMW) pattern. Only a slight increase in the urinary a1-microglobulin concentration and NAG activity was found in miners with the LMW pattern of urinary proteins. The results point to a slight glomerular and tubular damage in a significant proportion of exposed miners with increased absorption of mercury vapour.Pri profesionalnoj izloženosti parama elementarne žive (Hg0) mogu se pojaviti oštećenja bubrega. U ovom radu procjenjivana je mogućnost učinaka relativno kraće izloženosti nižim koncentracijama živinih para na glomerularnu i tubularnu funkciju bubrega. U 45 rudara su prije i nakon izloženosti određena živa i proteini u urinu. Nakon izloženosti određena je i aktivnost N-acetil-beta-D glukozaminidaze (NAG) u urinu. Proteini u urinu određeni su primjenom imunoelektroforeze, imunofiksacije i elektroforeze visoke rezolucije (velike sposobnosti razdvajanja), kao i pomoću kvantitativne analize albumina i alfa1-mikroglobulina. Rudari, inače, već duže intermitentno izloženi živinim parama, bili su u vrijeme istraživanja izloženi u prosjeku 37 (6–82) dana pri prosječnim koncentracijama 0,37 (0,05–0,73) mg/m3 zraka. Nakon izloženosti kod svih je rudara ustanovljena pojačana apsorpcija elementarne žive prosječnim koncentracijama žive u urinu 67,8±40,8 µg/g kreatinina. Imunoelektroforezom ustanovljene promjene u sastavu proteina u urinu nakon izloženosti su češće nego prije izloženosti (P<0,01). Kod tih rudara (u 22 od 45) s promjenama u sastavu proteina u urinu prevalencija uzoraka urina s proteinima velike molekularne mase veća je (15 od 45) nego prevalencija uzoraka urina s proteinima male molekularne mase (7 od 45). Nakon izloženosti koncentracije albumina u urinu nisu bile značajno povišene u odnosu na vrijednosti prije izloženosti. U podskupini rudara u čijim su urinima nađeni proteini male molekularne mase ustanovljen je blag porast alfa1- mikroglobulina (P=0,05). Živa u urinu nakon izloženosti u bila je u blagoj pozitivnoj korelaciji sa NAG u urinu (r=0,43; P<0,01). Prema ovim rezultatima moglo bi se zaključiti da je kod dijela promatranih osoba pojačana apsorpcija popraćena blagim – klinički neznačajnim – učincima na glomerularnu ili tubularnu funkciju bubrega. Promjene u sastavu proteina u urinu ustanovljene imunoelektroforetsim analizama, kvantitativne analize alfa1-mikroglobulina i NAG u urinu mogu se upotrijebiti kao biološki pokazatelj u zdravstvenom nadzoru radnika koji su intermitentno izloženi parama elementarne žive u niskim koncentracijama

Application of ultra performance liquid chromatography (uplc) for determination of Na+ /K+ atpase activity

An ion-pair ultra performance liquid chromatography (IP-UPLC) method was developed to obtain a sensitive and efficient means for quantification of ADP in order to follow the decrease of Na+ /K+ ATPase activity after its exposure to different inhibitors. The concentrations of ADP obtained after hydrolysis of ATP in the presence of enzyme depends on enzyme activity. Simultaneously with the chromatographic determination of ADP, the spectrophotometric determination of phosphates liberated after the hydrolysis of ATP was done.Physical chemistry 2008 : 9th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 24-28 September 200