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1.
Tiia Pedusaar Ilkka Sammalkorpi Arto Hautala Jaana Salujõe Ain Järvalt Margus Pihlak 《Hydrobiologia》2010,649(1):95-106
Lake ülemiste, the drinking water reservoir of Estonia’s capital city Tallinn, was biomanipulated by manual removal of cyprinids
in 2004–2006 and its impact on water quality in the vegetation period was studied. A total biomass of 156 tonnes corresponding
to 160 kg ha−1 of fish, predominantly cyprinids, were removed. A decline in the unit catches of fishing was observed. The removed fish biomass
versus phosphorus concentration of the lake was considered sufficient to reduce the impact of cyprinids on water quality.
The phosphorus removed within fish biomass corresponded to 38 μg l−1 and 21% of the external phosphorus load of the fishing period. The mean total phosphorus concentration dropped from >50 to
≤36 μg l−1. However, the densities of planktivorous young-of-the-year percids remained high and the role of zooplankton grazing in improving
water quality was found non-significant or transient. The cladocerans biomass decreased and the small-sized Daphnia cucullata remained almost the only daphnid in Lake ülemiste during and after the manipulation. Predomination of filamentous cyanobacteria
was replaced by a more diverse phytoplankton composition and co-domination of micro- and pico-sized colonial cyanobacteria
during summer. Mean phytoplankton biomass decreased from 15 to 6 mg l−1 primarily as a result of decreased in-lake TP availability. The Secchi disc transparency increased only in May 2005–2007.
The effects of coincidental events, a decline of external loading of phosphorus and a simultaneous flushing induced by heavy
rainfall, on lake water quality are discussed with some implications to the future management of the reservoir. 相似文献
2.
Sanna Loppi Paula Korhonen Maria Bouvy‐Liivrand Simone Caligola Tiia A. Turunen Mikko P. Turunen Ana Hernandez de Sande Natalia Koosowska Flavia Scoyni Anna Rosell Teresa García‐Berrocoso Sighild Lemarchant Hiramani Dhungana Joan Montaner Jari Koistinaho Katja M. Kanninen Minna U. Kaikkonen Rosalba Giugno Merja Heinniemi Tarja Malm 《Aging cell》2021,20(1)
3.
Mai Bl?ndal Tiia Ainla Toomas Marandi Aleksei Baburin Jaan Eha 《Cardiovascular diabetology》2012,11(1):1-8
Background
Chronic arterial stiffness contributes to the negative health effects of obesity and insulin resistance, which include hypertension, stroke, and increased cardiovascular and all-cause mortality. Weight loss and improved insulin sensitivity are individually associated with improved central arterial stiffness; however, their combined effects on arterial stiffness are poorly understood. The purpose of this study was to determine how insulin levels modify the improvements in arterial stiffness seen with weight loss in overweight and obese young adults.Methods
To assess the effects of weight loss and decreased fasting insulin on vascular stiffness, we studied 339 participants in the Slow the Adverse Effects of Vascular Aging (SAVE) trial. At study entry, the participants were aged 20?C45, normotensive, non-diabetic, and had a body-mass index of 25?C39.9?kg/m2. Measures of pulse wave velocity (PWV) in the central (carotid-femoral (cfPWV)), peripheral (femoral-ankle (faPWV)), and mixed (brachial-ankle (baPWV)) vascular beds were collected at baseline and 6?months. The effects of 6-month change in weight and insulin on measures of PWV were estimated using multivariate regression.Results
After adjustment for baseline risk factors and change in systolic blood pressure, 6-month weight loss and 6-month change in fasting insulin independently predicted improvement in baPWV but not faPWV or cfPWV. There was a significant interaction between 6-month weight change and change in fasting insulin when predicting changes in baPWV (p?<?0.001). Individuals experiencing both weight loss and insulin reductions showed the greatest improvement in baPWV.Conclusions
Young adults with excess weight who both lower their insulin levels and lose weight see the greatest improvement in vascular stiffness. This improvement in vascular stiffness with weight loss and insulin declines may occur throughout the vasculature and may not be limited to individual vascular beds.Trial registration
NCT00366990 相似文献4.
A qualitative liquid chromatography-electrospray ionization tandem mass spectrometry method was developed for screening of the abuse of 4-chlorodehydromethyltestosterone, danazol, fluoxymesterone, formebolone, metandienone, oxandrolone, and stanozolol. The introduced method measures simultaneously nine different 17-alkyl-substituted anabolic androgenic steroids or their unconjugated metabolites in human urine, using methyltestosterone as an internal standard. Sample preparation involved one-step liquid extraction. Liquid chromatographic separation was achieved on a reversed-phase column with methanol-water gradient containing 5 mmol/l ammonium acetate and 0.01% (v/v) acetic acid. Compounds were ionized in the positive mode and detected by multiple reaction monitoring. All steroids within the study could be selectively detected in urine with detection limits of 0.1-2.0 ng/ml. The method showed good linearity up to 250 ng/ml with correlation coefficients higher than 0.9947. With simple and fast sample preparation, low limits of detection, and high selectivity and precision, the developed method provides advantages over the present testing methods and has the potential for routine qualitative screening method of unconjugated 17-alkyl-substituted anabolic steroids in human urine. 相似文献
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6.
Phlebiopsis gigantea (Fr.) Jül. is one of the most common fungal species in coniferous forests and commonly used as a biological control agent to prevent aerial infections of conifers by Heterobasidion fungi. We used feeding experiments to examine whether Hylobius abietis L. (Coleoptera: Curculionidae) could serve as a vector for P. gigantea and associated viruses by disseminating the fungus in its faecal pellets. Two different P. gigantea strains were used in the experiments: the virus-free Rotsop biocontrol strain and P. gigantea 93073 infected with the virus strain PgLV-1. The Rotstop strain showed 100% viability during insect feeding, while the viability of the virus-infected strain 93073 was only 35%. Virus persistence was 100% during the passage of the host fungus through the alimentary tract. Based on growth experiments using virus-infected and virus-free strains obtained by hyphal tip or oidial isolation, the presence of PgLV-1 did not significantly affect the growth rate of the host fungus. 相似文献
7.
Urmas Kõljalg R. Henrik Nilsson Kessy Abarenkov Leho Tedersoo Andy F. S. Taylor Mohammad Bahram Scott T. Bates Thomas D. Bruns Johan Bengtsson‐Palme Tony M. Callaghan Brian Douglas Tiia Drenkhan Ursula Eberhardt Margarita Dueñas Tine Grebenc Gareth W. Griffith Martin Hartmann Paul M. Kirk Petr Kohout Ellen Larsson Björn D. Lindahl Robert Lücking María P. Martín P. Brandon Matheny Nhu H. Nguyen Tuula Niskanen Jane Oja Kabir G. Peay Ursula Peintner Marko Peterson Kadri Põldmaa Lauri Saag Irja Saar Arthur Schüßler James A. Scott Carolina Senés Matthew E. Smith Ave Suija D. Lee Taylor M. Teresa Telleria Michael Weiss Karl‐Henrik Larsson 《Molecular ecology》2013,22(21):5271-5277
The nuclear ribosomal internal transcribed spacer (ITS) region is the formal fungal barcode and in most cases the marker of choice for the exploration of fungal diversity in environmental samples. Two problems are particularly acute in the pursuit of satisfactory taxonomic assignment of newly generated ITS sequences: (i) the lack of an inclusive, reliable public reference data set and (ii) the lack of means to refer to fungal species, for which no Latin name is available in a standardized stable way. Here, we report on progress in these regards through further development of the UNITE database ( http://unite.ut.ee ) for molecular identification of fungi. All fungal species represented by at least two ITS sequences in the international nucleotide sequence databases are now given a unique, stable name of the accession number type (e.g. Hymenoscyphus pseudoalbidus|GU586904|SH133781.05FU), and their taxonomic and ecological annotations were corrected as far as possible through a distributed, third‐party annotation effort. We introduce the term ‘species hypothesis’ (SH) for the taxa discovered in clustering on different similarity thresholds (97–99%). An automatically or manually designated sequence is chosen to represent each such SH. These reference sequences are released ( http://unite.ut.ee/repository.php ) for use by the scientific community in, for example, local sequence similarity searches and in the QIIME pipeline. The system and the data will be updated automatically as the number of public fungal ITS sequences grows. We invite everybody in the position to improve the annotation or metadata associated with their particular fungal lineages of expertise to do so through the new Web‐based sequence management system in UNITE. 相似文献
8.
Enzyme-assisted synthesis and structure characterization of glucuronide conjugates of eleven anabolic steroid metabolites 总被引:1,自引:0,他引:1
Enzyme-assisted in vitro synthesis of eleven glucuronide-conjugated anabolic androgenic steroid (AAS) metabolites was performed using biphenyl-induced rat liver microsomal enzymes. The substrates within the study were the main compounds and metabolites detected in human urine after dosing of, e.g. metandienone, metenolone, methyltestosterone, nandrolone, and testosterone. Yields of glucuronidation reactions were 13-28% for most compounds, but significantly higher (77-78%) for the substrates with 4-ene-3-one double bond system of the steroid A-ring. Characterization of glucuronide-conjugated AAS structures was based on nuclear magnetic resonance spectroscopy ((1)H NMR) and on liquid chromatographic-mass spectrometric (LC-MS) and tandem mass spectrometric (LC-MS/MS) analyses in positive and negative ion mode electrospray ionization (ESI). Only minor differences were observed in optimal synthesis conditions between various substrates, which offer a potential to apply this in vitro assay as a default method for glucuronidation of new AAS substrates. The method allowed for a rapid production pathway of stereochemically pure AAS glucuronides in milligram amount, such as needed, e.g. in the development of analytical methods in forensic or pharmaceutical sciences, as well as in doping control. 相似文献
9.
Lake ülemiste is a shallow, eutrophic lake which has served the city of Tallinn as a water reservoir for many centuries. Its
light climate was studied by combining a routinely measured data set with a modelling approach. For 26 years (1978–2004),
data was collected on such optically active substances (OAS) and water parameters as water colour, turbidity and phytoplankton
biomass. Simple modelling enabled the quantification of long-term time-series data and the subsequent calculation of the diffuse
attenuation coefficient, euphotic depth and average light of the mixed layer. Several changes in the hydrological cycle have
taken place during the period under study, among which are an increase in the water level of about 0.5 m and a decrease in
the external water load from 108 million m3 year−1 to about 25 million m3 year−1. At the same time euphotic depth has shown a distinct trend towards increasing since the early 1990s. The euphotic depth
also showed an increase (from 1.1 to 1.4 m) due to an improvement in underwater light conditions – mainly in the spring (April
and May) and autumn (October and November) because of the lower amount of dissolved organic matter in the lake. The average
light availability in the mixed layer has increased, but this has not affected the phytoplankton biomass as the latter is
not light-limited during the summer period. 相似文献
10.