Modeling the recent drought and thinning impacts on energy, water and carbon fluxes in a boreal forest.

Globally, boreal forests act as important carbon sinks, however, drought and forest management could substantially alter the sink strength, though the controlling mechanisms of drought and management remain unclear. In this study, we combined the detailed process-based CoupModel with multiple measurements to study the impacts of recent drought and forest thinning on a boreal forest during 2018-2021. CoupModel after calibration showed high ability to represent the dynamics of long-term net ecosystem exchange and its responses to environmental changes.

Modeller subjectivity and calibration impacts on hydrological model applications: an event-based comparison for a road-adjacent catchment in south-east Norway.

Identifying a 'best' performing hydrologic model in a practical sense is difficult due to the potential influences of modeller subjectivity on, for example, calibration procedure and parameter selection. This is especially true for model applications at the event scale where the prevailing catchment conditions can have a strong impact on apparent model performance and suitability. In this study, two lumped models (CoupModel and HBV) and two physically-based distributed models (LISEM and MIKE SHE) were applied to a small catchment upstream of a road in south-eastern Norway.

Quantifying the hydrological impact of simulated changes in land use on peak discharge in a small catchment.

A physically-based, distributed hydrological model (MIKE SHE) was used to quantify overland runoff in response to four extreme rain events and four types of simulated land use measure in a catchment in Norway. The current land use in the catchment comprises arable lands, forest, urban areas and a stream that passes under a motorway at the catchment outlet. This model simulation study demonstrates how the composition and configuration of land use measures affect discharge at the catchment outlet differently in response to storms of different sizes.

Structure of the O-polysaccharide of Vibriocholerae O43 containing a new monosaccharide derivative, 4-(N-acetyl-l-allothreonyl)amino-4,6-dideoxy-D-glucose.

The O-polysaccharide of Vibrio cholerae O43 was studied using chemical analyses, triflic acid solvolysis and 2D NMR spectroscopy, including (1)H/(1)H COSY, TOCSY, NOESY and (1)H/(13)C gradient-selected HSQC experiments. The following structure of the tetrasaccharide repeating unit of the polysaccharide was established: →3)-β-D-Quip4NAcyl-(1→3)-α-D-GalpNAcA-(1→4)-α-D-GalpNAc-(1→3)-α-D-QuipNAc-(1→ where D-QuiNAc stands for 2-acetamido-2,6-dideoxy-D-glucose, D-Qui4NAcyl for 4-(N-acetyl-L-allothreonyl)amino-4,6-dideoxy-D-glucose and D-GalNAcA for 2-acetamido-2-deoxy-D-galacturonic acid.

Arctic vegetation damage by winter-generated coal mining pollution released upon thawing.

Acid mine drainage (known as AMD) is a well-known environmental problem resulting from the oxidation of sulfidic mine waste. In cold regions, AMD is often considered limited by low temperatures most of the year and observed environmental impact is related to pollution generated during the warm summer period. Here we show that heat generation within an oxidizing, sulfidic, coal-mining waste-rock pile in Svalbard (78 degrees N) is high enough to keep the pile warm (roughly 5 degrees C throughout the year) despite mean annual air temperatures below -5 degrees C.

Modeling carbon turnover in five terrestrial ecosystems in the boreal zone using multiple criteria of acceptance.

Estimates of carbon fluxes and turnover in ecosystems are key elements in the understanding of climate change and in predicting the accumulation of trace elements in the biosphere. In this paper we present estimates of carbon fluxes and turnover times for five terrestrial ecosystems using a modeling approach. Multiple criteria of acceptance were used to parameterize the model, thus incorporating large amounts of multi-faceted empirical data in the simulations in a standardized manner.

Sequence determination of oligosaccharides and regular polysaccharides using NMR spectroscopy and a novel Web-based version of the computer program CASPER.

A WWW-interface to a program for structure elucidation of oligo- and polysaccharides using NMR data, CASPER, is presented. The interface and the underlying program have been extensively tested using published data and it was able to simulate 13C NMR spectra of >200 structures with an average error of about 0.3 ppm/resonance.

Role of Helicobacter pylori rfaJ genes (HP0159 and HP1416) in lipopolysaccharide synthesis.

The genome of Helicobacter pylori 26695 has been sequenced and the lipopolysaccharide (LPS) O sidechain of this strain has been shown to express both Lewis x and Lewis y units. To determine the role of HP0159 and HP1416, genes recognized as rfaJ homologs and implicated in LPS synthesis, isogenic mutants of H. pylori 26695 were generated.

Structure of a highly phosphorylated O-polysaccharide of Proteus mirabilis O41.

A highly phosphorylated O-polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Proteus mirabilis O41 followed by GPC. The initial and dephosphorylated polysaccharides and phosphorylated products from two sequential Smith degradations were studied by (1)H, (13)C and (31)P NMR spectroscopy and ESI-MS. The O-polysaccharide was found to have a tetrasaccharide repeating unit containing one ribitol phosphate (presumably d-Rib-ol-5-P) and two ethanolamine phosphate (Etn-P) groups, one of which is present in the stoichiometric amount and the other in a nonstoichiometric amount.

A unique variant of streptococcal group O-antigen (C-polysaccharide) that lacks phosphocholine.

Streptococcus mitis strain SK598, which represents a subgroup of biovar 1, possesses a unique variant of the C-polysaccharide found in the cell wall of all strains of Streptococcus pneumoniae and in some strains of S. mitis. This new variant lacks the choline methyl groups in contrast to the previously characterized forms of C-polysaccharide, which all contain one or two choline residues per repeat.

The structure of the O-chain of the lipopolysaccharide of a prototypal diarrheagenic strain of Hafnia alvei that has characteristics of a new species under the genus Escherichia.

The structure of the O-polysaccharide of the lipopolysaccharide from a diarrheal strain isolated in Bangladesh was studied with sugar, and methylation analysis, NMR spectroscopy, mass spectrometry and partial acid hydrolysis. The strain was first designated as Hafnia alvei, but later found to be a possible new species in the genus Escherichia. Two different polysaccharides were detected, a major and a minor one.

Structure of the O-polysaccharide from the lipopolysaccharide from Vibrio cholerae O6.

The O-polysaccharide from Vibrio cholerae O6 was isolated from the LPS by mild-acid hydrolysis and has been investigated by sugar and methylation analysis and NMR spectroscopy. The polysaccharide was also depolymerized with aqueous hydrofluoric acid to give the repeating unit and multiples thereof. The O-polysaccharide had the following tetrasaccharide repeating unit.

Frequencies of lipopolysaccharide-defined epitopes in Haemophilus influenzae type b and non-typable isolates determined with monoclonal antibodies.

OBJECTIVE: To investigate the frequency of expression and stability of saccharide epitopes in 178 Haemophilus influenzae (39 type b and 138 non-typable) isolates from blood, cerebrospinal fluid, nasopharynx, pharynx, middle ear, conjunctiva, and pleural and bronchial fluid from symptomatic and asymptomatic children using five murine monoclonal antibodies (MAbs, MAHI 3, 4, 6, 8, 10) specific for the oligosaccharide moiety of the lipopolysaccharide (LPS) of H. influenzae, which recognize defined saccharide structures. METHODS: A whole bacteria enzyme immunoassay (EIA) and colony dot immunoblotting were used to determine the frequency of expression and stability of saccharide epitopes in the 178 H.

Phenotypic variation in molecular mimicry between Helicobacter pylori lipopolysaccharides and human gastric epithelial cell surface glycoforms. Acid-induced phase variation in Lewis(x) and Lewis(y) expression by H. Pylori lipopolysaccharides.

Helicobacter pylori is an important gastroduodenal pathogen of humans whose survival in the gastric environment below pH 4 is dependent on bacterial production of urease, whereas above pH 4 urease-independent mechanisms are involved in survival, but that remain to be elucidated fully. Previous structural investigations on the lipopolysaccharides (LPSs) of H. pylori have shown that the majority of these surface glycolipids express partially fucosylated, glucosylated, or galactosylated N-acetyllactosamine (LacNAc) O-polysaccharide chains containing Lewis(x) (Le(x)) and/or Lewis(y) (Le(y)), although some strains also express type 1 determinants, Lewis(a), Lewis(b), and H-1 antigen.