Effect of storage on bovine erythrocyte cholinesterase activity.

Bovine whole blood and washed erythrocyte samples with either sodium heparin or EDTA as the anticoagulant were stored at -24, 2 to 3, 21, or 37 C for up to 8 weeks to determine the stability of erythrocyte cholinesterase (ChE) activity. An automated colorimetric method was used to measure ChE activity. Regression analysis was used to estimate the rate of decline of ChE activity of samples to 95% of normal. Samples stored at -24 and 2 to 3 C were very stable, and ChE activity was maintained for several weeks or longer. Samples stored at 21 C maintained an activity level not less than 95% of normal for at least 9 days and those stored at 37 C for at least 2 days. The type of anticoagulant used did not appear to affect significantly the stability of activity.     

Efficient application of in vitro anther culture for different European winter wheat (Triticum aestivum L.) breeding programmes

The efficiency of our anther culture protocol was tested with high‐ and low‐responding genotypes, ‘Svilena’ and ‘Berengar’, and 93 F₁ winter wheat crosses in 2010 and 2011. Based on data for these genotypes, the effect of genotype influenced the number of embryo‐like structures, regenerated plantlets and green plantlets, while the number of albino plantlets was affected by genotype, year and environmental factors. Although genotype also influenced the production of green plantlets from breeding crosses, with green plantlets per 100 anthers ranging from 0.04 to 28.67, the average regeneration rate over all crosses was 5.3 green plantlets/100 anthers, which resulted in a total of 11 416 well‐rooted green plantlets. The survival rate of green plantlets following acclimatization was 97.21% in 2010 and 96.34% in 2011. In this study, the phenomenon of albinism and genotype dependency did not hinder the production of more than five thousand green plantlets each year. In our experiments, anther culture proved to be an efficient method in winter wheat breeding programmes with lower costs than alternative technologies.     

Distribution of structure and lignin within growth rings of Norway spruce

A radial core from a Norway spruce (Picea abies (L.) Karst.) estimated to be about 107 years old was cut from a board and was analyzed for density and microfibril angle (MFA). Furthermore, cell geometry, wall thickness and lignin distribution were analyzed on three selected growth rings in detail. Intra-ring differences in the density profiles are also true for cell wall thicknesses as well as radial and tangential lumen diameters. A higher MFA was found for earlywood with a slow decrease toward the latewood region. The lignin was found to remain rather constant throughout the growth rings, which suggests a constant chemical composition of the cell wall material within the growth ring. From the recorded datasets on a cellular level, it can be concluded that the main adaptation regarding structure–property relationships toward the optimization of water transport and mechanical stability is mainly achieved at the cell level.     

Within- and between-stand variation in selected properties of Sitka spruce sawn timber in the UK: implications for segregation and grade recovery

Context

Information on wood properties variation is needed by forest growers and timber processors to best utilise the available forest resource and to guide future management.

Aim

This study aims to quantify the variation in selected properties of Sitka spruce (Picea sitchensis (Bong.) Carr.) structural timber.

Methods

Twelve harvest-age stands were selected, ten trees per site were felled and processed into 301 logs. Dynamic modulus of elasticity (MOE_dyn) was measured on each tree and log using portable acoustic instruments. Logs were processed into structural timber and its MOE and bending strength was determined.

Results

Overall, the timber satisfied the MOE, bending strength and density requirements for the C16 strength class. Approximately 25 % of the total variation in timber mechanical properties was attributed to between-stand differences, with the remaining 75 % attributed to within-stand differences. A series of equations were developed to predict site, tree and log-level variation in timber properties.

Conclusion

Knowledge of the site and stand factors that are associated with differences in timber properties can assist with segregation of the current resource. Portable acoustic tools can also be used to increase the stiffness of sawn timber by segregating out individual trees and logs that will yield low stiffness timber.     

Plastin 3 is a protective modifier of autosomal recessive spinal muscular atrophy

Homozygous deletion of the survival motor neuron 1 gene (SMN1) causes spinal muscular atrophy (SMA), the most frequent genetic cause of early childhood lethality. In rare instances, however, individuals are asymptomatic despite carrying the same SMN1 mutations as their affected siblings, thereby suggesting the influence of modifier genes. We discovered that unaffected SMN1-deleted females exhibit significantly higher expression of plastin 3 (PLS3) than their SMA-affected counterparts. We demonstrated that PLS3 is important for axonogenesis through increasing the F-actin level. Overexpression of PLS3 rescued the axon length and outgrowth defects associated with SMN down-regulation in motor neurons of SMA mouse embryos and in zebrafish. Our study suggests that defects in axonogenesis are the major cause of SMA, thereby opening new therapeutic options for SMA and similar neuromuscular diseases.     

Progesterone and Luteinizing hormone secretion patterns in early pregnant gilts

We studied luteinizing hormone (LH) pulsatility and episodic progesterone release of the corpus luteum (CL) on Day 11 and Day 21 in inseminated gilts and aimed to establish a relationship between these two hormones. Blood was collected at 15-min intervals for 12 hr on Days 11, 16 and 21 from a vena cava caudalis catheter. At euthanasia, eight gilts were pregnant and six gilts were not pregnant. Progesterone parameters (basal, mean, pulse frequency and pulse amplitude) did not differ between pregnant and non-pregnant gilts on Day 11, LH pulse frequency and amplitude tended to differ (p = .07 and p = .079). In pregnant gilts, basal and mean progesterone, progesterone pulse amplitude and frequency declined significantly from Day 11 to Day 21 (p < .05). A significant decline was also seen in the LH pulse amplitude from Day 11 to Day 21 (p < .05). None of the LH pulses was followed by a progesterone pulse within 1 hr on Day 21. On Day 11 and Day 21 appeared a synchronicity in the LH pulse pattern, as there were two or three LH pulses in 12 hr and these LH pulses appeared in the same time window. We conclude that on Day 11 and Day 21 of pregnancy in gilts, progesterone pulses do not follow an LH pulse within one hour. Further we demonstrated that the successful or not successful formation of a CL of pregnancy is independent of progesterone release on Day 11 after insemination. We confirmed the decline of progesterone from Day 11 to Day 21 in the vena cava caudalis and could demonstrate that this decline is partly due to lower progesterone pulse amplitude and frequency and that the decline occurs simultaneously with a decline in LH pulse amplitude.     

Evolution of planetary cores and the Earth-Moon system from Nb/Ta systematics

It has been assumed that Nb and Ta are not fractionated during differentiation processes on terrestrial planets and that both elements are lithophile. High-precision measurements of Nb/Ta and Zr/Hf reveal that Nb is moderately siderophile at high pressures. Nb/Ta values in the bulk silicate Earth (14.0 +/- 0.3) and the Moon (17.0 +/- 0.8) are below the chondritic ratio of 19.9 +/- 0.6, in contrast to Mars and asteroids. The lunar Nb/Ta constrains the mass fraction of impactor material in the Moon to less than 65%. Moreover, the Moon-forming impact can be linked in time with the final core-mantle equilibration on Earth 4.533 billion years ago.     

Oily waste containing natural radionuclides: does it cause stimulation or inhibition of soil bacterial community?

Contamination with oily wastes containing natural radionuclides is a potential hazard for soil health and function. Our study aimed to reveal both structural and functional changes of the microbial community resistant to and able to decompose oily wastes in soil. To do this, we determined CO₂ efflux, microbial biomass (by the extraction‐fumigation method), and community structure (by PCR‐SSCP) for 120 d after application of radioactive oily wastes to the soil at the ratio 1:4. The addition of the waste resulted in an increase of the activity concentration of ²²⁶Ra by 130 times (up to 643 Bq kg^?1) and of ²³²Th by 29 times (up to 254 Bq kg^?1). The calculated weighted dose for the radionuclide ²²⁶Ra was found to be below the values that are known to affect microorganisms. However, the cumulative effect of a repeated deposition of radioactive oily waste may result in an increase of the weighted dose up to an effective level. During the incubation, the hydrocarbon (HC) content of the waste‐treated soil decreased from 156 to 54 g kg^?1 of soil indicating intensive decomposition of added organics by soil microorganisms. The waste application, however, led to an inhibition of soil microbial biomass compared with the control (by 26–47%). Microbial respiration was stimulated in the first month of incubation and then decreased until the end of the incubation period (by up to 74% compared to the control). The qCO₂ was estimated to be 3‐fold higher than the control on day 1 of incubation and equal to the control on day 120 of incubation. The bacterial diversity decreased in the contaminated soil compared with the control soil. The bacterial community structure was altered by domination of new oil degrader species belonging to the genera Dyella, Pseudoxanthomonas, Sinobacter, and Parvibaculum. Thus, disposal of radioactive petroleum waste strongly altered the structure of the microbial community resulting in the selection of resistant species able to decompose pollutants and also affected the community function (inhibition of microbial biomass and stimulation of respiration) which tended to stabilize after long‐term incubation.     

Cardiovascular responses to acute handling stress in the Antarctic fish Trematomus bernacchii are not mediated by circulatory catecholamines

Cannulated specimens of the benthic Antarctic teleost Trematomus bernacchii were subjected to a five min period of handling stress, following which blood pressures were measured and then blood samples taken for measurement of plasma catecholamine concentrations. There were two control groups of fish, one group of undisturbed fish at Scott Base, Antarctica and the other group of undisturbed fish measured in Christchurch.Plasma catecholamine concentrations were not changed following 5 min of acute handling stress. However, heart rate, ventral aortic blood pressure and haematocrit were elevated following handling, suggesting increased sumpathetic nerve activity. The low plasma catecholamine concentrations measured in all three groups of fish are similar to those found in other species of teleost at rest.The resting heart rates found in this series of experiments were approximately double those recorded in previous work on this species and this difference may be correlated with the length of time that the fish are held in captivity. The fish transported to Christchurch also had higher mean cell haemoglobin concentrations (MCHC) and lower plasma chloride concentrations.     

Anxiogenic behaviour induced by 17α-ethynylestradiol in male guppies (<Emphasis Type="Italic">Poecilia reticulata</Emphasis>)

Behaviour studies are used in toxicology research as they are excellent tools to measure physiological end-points caused by exogenous chemicals. In mammals both reproductive and non-reproductive behaviours have been used for a long period of time, whereas in teleost fishes non-reproductive behaviours have received little attention compared to reproductive behaviours. Recent advances in measuring stress related behaviours in zebrafish have provided additional tools to understand behaviour toxicology in fish. One species with well documented reproductive behaviour disturbed by different toxicants is the guppy, which is better suited than zebrafish for reproductive behaviour studies and therefore might be a better model organism for comparative behaviour studies in fish toxicology. Here we report new applications for non-reproductive behaviours in guppy and test these behaviours on males treated with the endocrine disruptor 17α-ethynylestradiol at environmentally relevant concentrations. 17α-ethynylestradiol increased freezing and bottom-dwelling when fish were placed in a non-familiar aquarium, but did not significantly affect shoaling behaviour. These results are similar to the anxiogenic behaviours seen in rats treated perinatally with 17α-ethynylestradiol and add more concern to the impacts of endocrine disruptors on aquatic wildlife.