The size of a vendace, Coregonus albula L., stock in a deep lake basin monitored by hydroacoustic methods

An acoustic estimate of the number and biomass of a vendace stock (age >2 + years) in a deep basin of Lake Karjalan Pyhäjärvi was made in August 1985. The acoustic data were collected at night during the summer stagnation. The vendace were on the lake bottom during the day and rose by midnight to the hypolimnion; they did not rise to the thermocline or water layers above it. In the research area the mean number of vendace was 1900 fish ha ⁻¹ and the mean biomass was 76 kg ha ⁻¹. Total vendace biomass was 151 in the whole 200-ha research area.     

Virulence plasmid-associated autoagglutination in Yersinia spp.

The autoagglutination of Yersinia enterocolitica was dependent on the presence of the virulence plasmid and on the active growth of bacteria in tissue culture media at 37 degrees C. Cultures with a high initial concentration of bacteria failed to autoagglutinate , indicating that synthesis of new virulence plasmid-associated surface factors was essential for autoagglutination. The synthesis of a plasmid-encoded polypeptide (molecular weight, 240,000), designated P1, that could be dissociated under strongly reducing conditions into subunits of 52,500 daltons was found to be correlated with autoagglutination. Further, a strain of Yersinia pseudotuberculosis [ YPIII ( PIB102 )], which has Tn5 inserted within the structural gene of P1 that prevents the synthesis of P1, failed to autoagglutinate , in contrast to the wild-type strain, strongly indicating that P1 is involved in this phenomenon. It was also found by immunoblotting that in addition to the common response to temperature, the P1 proteins of Y. enterocolitica and Y. pseudotuberculosis were immunologically related.     

Spatial and environmental components of variation in the distribution patterns of subarctic plant species at Kevo, N Finland — a case study at the meso-scale level

This study presents a quantitative partitioning of the total variance in the patterns of occurrence of 231 vascular plant taxa in 362 1 × 1 km grids in the Kevo Nature Reserve into four independent components: purely spatial variation, spatially structured environmental variation, non-spatial environmental variation, and unexplained variation. This partitioning is done with (partial) constrained ordinations (canonical correspondence analysis) and associated Monte Carlo permutation tests. The numerical results suggest that most of the biological variance captured by the external explanatory variables is related to 'local' meso-scale environmental factors, as 12.6% of the variation in the species data is explained solely by the environmental variables. Part of the variance (6%) represents a spatially covarying environmental component, but only a very small part, ca 2%, is related to purely spatial variation. The amount of unexplained variation is very high (>75%). The results are compared and discussed in relation to the relative amounts of these four variance components at broader- and finer-scales and to the concepts of domains and transition zones of scales in biological patterning.     

Alu-Alu recombination results in a duplication of seven exons in the lysyl hydroxylase gene in a patient with the type VI variant of Ehlers-Danlos syndrome.

The type VI variant of the Ehlers-Danlos syndrome (EDS) is a recessively inherited connective-tissue disorder. The characteristic features of the variant are muscular hypotonia, kyphoscoliosis, ocular manifestations, joint hypermobility, skin fragility and hyperextensibility, and other signs of connective-tissue involvement. The biochemical defect in most but not all patients is a deficiency in lysyl hydroxylase activity. Lysyl hydroxylase is an enzyme that catalyzes the formation of hydroxylysine in collagens and other proteins with collagen-like amino acid sequences. We have recently reported an apparently homozygous large-duplication rearrangement in the gene for lysyl hydroxylase, leading to the type VI variant of EDS in two siblings. We now report an identical, apparently homozygous large duplication in an unrelated 49-year-old female originally analyzed by Sussman et al. Our simple-sequence-repeat-polymorphism analysis does not support uniparental isodisomy inheritance for either of the two duplications. Furthermore, we indicate in this study that the duplication in the lysyl hydroxylase gene is caused by an Alu-Alu recombination in both families. Cloning of the junction fragment of the duplication has allowed synthesis of appropriate primers for rapid screening for this rearrangement in other families with the type VI variant of EDS.     

CO2 exchange in the Empetrum nigrum-Sphagnum fuscum community

Summary The CO₂ exchange of the Empetrum nigrum-Sphagnum fuscum community of a raised bog was studied in the laboratory at different temperature (from 5 to 30° C) and irradiance (up to 128 W m^-2) combinations during one growing season. The total CO₂ exchange was divided into three components, namely those due to Empetrum nigrum, Sphagnum fuscum, and peat, respectively. At the optimum temperature (10 to 15° C) the maximum net CO₂ exchange of Empetrum nigrum was c. 200 and that of Sphagnum fuscum c. 250 mg CO₂ m^-2h^-1. The total respiration in peat increased exponentially from 50 to 350 mg CO₂ m^-2h^-1 with increasing temperature from 5 to 30° C. About 40% of the CO₂ fixed by the community in optimal temperature and irradiation conditions was released immediately.     

A confirmatory analysis of malachite green residues in rainbow trout with liquid chromatography-electrospray tandem mass spectrometry

A quantitative liquid chromatography-tandem mass spectrometric (LC-MS/MS) method has been developed for the determination of malachite green (MG) and its metabolite leucomalachite green (LMG) in fish. Residues were extracted with an acetonitrile-acetate buffer and purified using the automated solid-phase extraction (ASPEC). Residues were analyzed with a reversed-phase LC-MS/MS using a positive-ion electrospray ionisation (ESI). Isotope-labelled leucomalachite green (LMG-D5) was used as an internal standard for the quantification of LMG residues. The related dye, brilliant green (BG) was used as an instrumental standard. Identification and quantification of analytes were based on the ion transitions monitored by multiple reaction monitoring (MRM). The decision limit (CCalpha) for MG and LMG was 0.13 and 0.16 microgkg(-1). The respective detection capabilities (CCbeta) were 0.22 and 0.27 microgkg(-1). The absolute recovery (repeatability SD(r)) was in the range of 58-65% (7.8-11.2%) for MG and 59-68% (9.7-16.9%) for LMG. LMG was quantified also based on the internal standard, giving a recovery (repeatability SD(r)) of 103-110% (4.8-9.3%). The method was further evaluated by analyzing a total of 34 fish residue monitoring samples, of which eight samples were found to be non-compliant containing low residues of LMG.     

Effects of ovariectomy and estrogen treatment on learning and hippocampal neurotransmitters in mice

This study examined the effects of long-term estrogen treatment (sc 17 beta-estradiol minipellets) on learning in C57BL/6J female and male mice using a position discrimination task in the T-maze and a win-stay task (1/8 arms baited) in the radial arm maze (RAM). In addition, hippocampal monoamines and ChAT activity were measured at the end of the study and correlated to task performance. Female sham-operated (gonadally intact) and ovariectomized (OVX) mice were treated with estrogen either for 7 or 40 days before the behavioral tests and intact male mice for 7 days before the behavioral tests. In sham-operated mice the 40-day estrogen treatment improved RAM performance and in OVX mice both the 7- and 40-day estrogen treatments improved the performance in both maze tasks. The estrogen treatment also improved RAM performance in males. The hippocampal ChAT, NA, 5-HIAA, and DOPAC levels were decreased in OVX mice. Furthermore, the effects of estrogen treatment on the levels of hippocampal 5-HT and its metabolite 5-HIAA were different in sham-operated than in OVX mice. We could find no correlation between cognitive measures and neurochemical variables. This study gives new information about the effects of estrogen on learning and hippocampal neurotransmitters in mice.     

p53-independent apoptosis in UV-irradiated mouse skin: possible inhibition by 50 Hz magnetic fields

Our recent results suggest that 50 Hz magnetic fields (MF) enhance ultraviolet (UV)-induced tumorigenesis in mouse skin. The aim of the present experiment was to study suppression of apoptosis as a possible mechanism for MF effects on skin tumorigenesis. Another aim was to test the importance of a UV and MF exposure schedule, particularly the role of MF exposure prior to UV irradiation. Female mice were exposed to a UV dose of 2 human MED and to 100 microT MF of 50 Hz, using the following exposure schedules: group 1 sham MF 24 h, UV 1 h, sham MF 24 h; group 2 sham MF 24 h, UV 1 h, MF 24 h; group 3 MF 24 h, UV 1 h, MF 24 h. Lamps emitting simulated solar radiation (SSR) were used for UV irradiation. Skin samples were analysed for apoptosis, expression of the p53 gene, activity of the enzyme ornithine decarboxylase (ODC) and polyamine concentrations. A significantly (p = 0.017) lower number of apoptotic cells was measured in group 2 compared to group 1. A similar but not statistically significant (p = 0.064) decrease was also detected in group 3. No p53 expression was detected in any sample. The levels of ODC and putrescine did not differ significantly between the UV-only and UV and MF-exposed groups. Spermidine and spermine levels were significantly (p = 0.014 and 0.014, respectively) lower in group 3 than in group 1, but no decrease was observed in group 2. Our findings suggest that SSR induces p53-independent apoptosis in mouse skin and that the apoptotic response may be inhibited by exposure to MF. The exposure schedule did not alter the MF effect. The results do not support a causal role for polyamines in MF effects on apoptosis.     

Family-Based Cluster Randomized Controlled Trial Enhancing Physical Activity and Motor Competence in 4–7-Year-Old Children

Little is known of how to involve families in physical activity (PA) interventions for children. In this cluster randomized controlled trial, we recruited families with four- to seven-year-old children to participate in a year-long study where parents in the intervention group families (n = 46) received tailored counseling to increase children’s PA. Structured PA was not served. Control group families (n = 45) did not receive any counseling. PA in all children (n = 91; mean age 6.16 ± 1.13 years at the baseline) was measured by accelerometers at the baseline and after three, six, nine and 12 months. Motor competence (MC) (n = 89) was measured at the baseline and after six and 12 months by a KTK (KörperkoordinationsTest für Kinder) and throwing and catching a ball (TCB) protocols. The effect of parental counseling on study outcomes was analyzed by a linear mixed-effects model fit by REML and by a Mann-Whitney U test in the case of the TCB. As season was hypothesized to affect counseling effect, an interaction of season on the study outcomes was examined. The results show significant decrease of MVPA in the intervention group when compared to the control group (p < .05). The TCB showed a nearly significant improvement at six months in the intervention group compared to the controls (p = .051), but not at 12 months. The intervention group had a steadier development of the KTK when the interaction of season was taken into account. In conclusion, more knowledge of family constructs associating with the effectiveness of counseling is needed for understanding how to enhance PA in children by parents. However, a hypothesis may be put forward that family-based counseling during an inactive season rather than an active season may provide a more lasting effect on the development of KTK in children.

Trial Registration

Controlled-Trials.com ISRCTN28668090     

Moving through Life-Space Areas and Objectively Measured Physical Activity of Older People

Objectives

Physical activity–an important determinant of health and function in old age–may vary according to the life-space area reached. Our aim was to study how moving through greater life-space areas is associated with greater physical activity of community-dwelling older people. The association between objectively measured physical activity and life-space area reached on different days by the same individual was studied using one-week longitudinal data, to provide insight in causal relationships.

Methods

One-week surveillance of objectively assessed physical activity of community-dwelling 70–90-year-old people in central Finland from the “Life-space mobility in old age” cohort substudy (N = 174). In spring 2012, participants wore an accelerometer for 7 days and completed a daily diary including the largest life-space area reached (inside home, outside home, neighborhood, town, and beyond town). The daily step count, and the time in moderate (incl. walking) and low activity and sedentary behavior were assessed. Differences in physical activity between days on which different life-space areas were reached were tested using Generalized Estimation Equation models (within-group comparison).

Results

Participants’ mean age was 80.4±4.2 years and 63.5% were female. Participants had higher average step counts (p < .001) and greater moderate and low activity time (p < .001) on days when greater life-space areas were reached, from the home to the town area. Only low activity time continued to increase when moving beyond the town.

Conclusion

Community-dwelling older people were more physically active on days when they moved through greater life-space areas. While it is unknown whether physical activity was a motivator to leave the home, intervention studies are needed to determine whether facilitation of daily outdoor mobility, regardless of the purpose, may be beneficial in terms of promoting physical activity.