Comparison of Worm Control Strategies in Grazing Sheep in Denmark

Control of nematode parasites with reduced reliance on the use of anthelmintics was studied in 16 ewes with suckling twin lambs on contaminated pasture in Denmark. Ewes and lambs were treated with albendazole at turn-out 3 May. Ewes were removed from the groups on 26 July, and lambs were slaughtered on 11 October. The animals were allocated to 4 groups of 8 lambs and their 4 ewes. Group TS was treated with albendazole at weeks 3, 6 and 8 after turnout and set-stocked; group TM was similarly treated but moved to clean pasture in conjunction with the last drenching; group US was untreated and set-stocked, and group UM was left untreated but moved to clean pasture week 8 after turn-out. Supplementary feed was offered in June and August due to scarcity of pasture. Strategic treatments of ewes and lambs weeks 3, 6 and 8 after turn-out, with or without a move to clean pasture, were highly effective in controlling nematode infections for most of the season. This was reflected in better weight gains and carcass characteristics in the treated compared to untreated lambs, resulting in an average increase in the value of the product by 36%. The effect of moving without treatment (UM) on faecal egg counts was limited but peak pasture infectivity was reduced to less than 10% compared to the set-stocked group and weight gains of lambs were significantly better despite poor feed availability in late season. The study showed that under set-stocked conditions repeated anthelmintic treatments of both ewes and lambs in early season may ensure sufficient nematode control whereas moving animals to clean pasture without dosing was less efficient. The latter may, however, still be a viable option in organic and other production systems where routine use of anthelmintics is banned, particularly if weaning and moving are combined or a second move is performed.     

Direct exchange of vitamin B12 is demonstrated by modelling the growth dynamics of algal–bacterial cocultures

The growth dynamics of populations of interacting species in the aquatic environment is of great importance, both for understanding natural ecosystems and in efforts to cultivate these organisms for industrial purposes. Here we consider a simple two-species system wherein the bacterium Mesorhizobium loti supplies vitamin B₁₂ (cobalamin) to the freshwater green alga Lobomonas rostrata, which requires this organic micronutrient for growth. In return, the bacterium receives photosynthate from the alga. Mathematical models are developed that describe minimally the interdependence between the two organisms, and that fit the experimental observations of the consortium. These models enable us to distinguish between different mechanisms of nutrient exchange between the organisms, and provide strong evidence that, rather than undergoing simple lysis and release of nutrients into the medium, M. loti regulates the levels of cobalamin it produces, resulting in a true mutualism with L. rostrata. Over half of all microalgae are dependent on an exogenous source of cobalamin for growth, and this vitamin is synthesised only by bacteria; it is very likely that similar symbiotic interactions underpin algal productivity more generally.     

Rate of progression of CT-quantified emphysema in male current and ex-smokers: a follow-up study

Background

Little is known about the factors associated with CT-quantified emphysema progression in heavy smokers. The objective of this study was to investigate the effect of length of smoking cessation and clinical / demographical factors on the rate of emphysema progression and FEV₁-decline in male heavy smokers.

Methods

3,670 male smokers with mean (SD) 40.8 (17.9) packyears underwent chest CT scans and pulmonary function tests at baseline and after 1 and 3 years follow-up. Smoking status (quitted ≥5, ≥1-<5, <1 years or current smoker) was noted. Rate of progression of emphysema and FEV₁-decline after follow-up were assessed by analysis of variance adjusting for age, height, baseline pulmonary function and emphysema severity, packyears, years in study and respiratory symptoms. The quitted ≥5 group was used as reference.

Results

Median (Q1-Q3) emphysema severity,<-950 HU, was 8.8 (5.1 – 14.1) and mean (SD) FEV₁ was 3.4 (0.73) L or 98.5 (18.5) % of predicted. The group quitted ‘>5 years’ showed significantly lower rates of progression of emphysema compared to current smokers, 1.07% and 1.12% per year, respectively (p<0.001). Current smokers had a yearly FEV₁-decline of 69 ml, while subjects quit smoking >5 years had a yearly decline of 57.5 ml (p<0.001).

Conclusion

Quit smoking >5 years significantly slows the rate of emphysema progression and lung function decline.

Trial registration

Registered at http://www.trialregister.nl with trial number ISRCTN63545820.     

Identifying the neural circuitry of alcohol craving and relapse vulnerability

With no further intervention, relapse rates in detoxified alcoholics are high and usually exceed 80% of all detoxified patients. It has been suggested that stress and exposure to priming doses of alcohol and to alcohol-associated stimuli (cues) contribute to the relapse risk after detoxification. This article focuses on neuronal correlates of cue responses in detoxified alcoholics. Current brain imaging studies indicate that dysfunction of dopaminergic, glutamatergic and opioidergic neurotransmission in the brain reward system (ventral striatum including the nucleus accumbens) can be associated with alcohol craving and functional brain activation in neuronal systems that process attentional relevant stimuli, reward expectancy and experience. Increased functional brain activation elicited by such alcohol-associated cues predicted an increased relapse risk, whereas high brain activity elicited by affectively positive stimuli may represent a protective factor and was correlated with a decreased prospective relapse risk. These findings are discussed with respect to psychotherapeutic and pharmacological treatment options.     

Histological and immunohistochemical effects of Curcuma longa on activation of rat hepatic stellate cells after cadmium induced hepatotoxicity

The liver is a target for toxic chemicals such as cadmium (Cd). When the liver is damaged, hepatic stellate cells (HSC) are activated and transformed into myofibroblast-like cells, which are responsible for liver fibrosis. Curcuma longa has been reported to exert a hepato-protective effect under various pathological conditions. We investigated the effects of C. longa administration on HSC activation in response to Cd induced hepatotoxicity. Forty adult male albino rats were divided into: group 1 (control), group 2 (Cd treated), group 3 (C. longa treated) and group 4 (Cd and C. longa treated). After 6 weeks, liver specimens were prepared for light and electron microscopy examination of histological changes and immunohistochemical localization of alpha smooth muscle actin (αSMA) as a specific marker for activated HSC. Activated HSC with a positive αSMA immune reaction were not detected in groups 1 and 3. Large numbers of activated HSC with αSMA immune reactions were observed in group 2 in addition to Cd induced hepatotoxic changes including excess collagen deposition in thickened portal triads, interlobular septa with hepatic lobulation, inflammatory cell infiltration, a significant increase in Kupffer cells and degenerated hepatocytes. In group 4, we observed a significant decrease in HSC that expressed αSMA with amelioration of the hepatotoxic changes. C. longa administration decreased HSC activation and ameliorated hepatotoxic changes caused by Cd in adult rats.     

Name change for the Cambrian trilobite <Emphasis Type=Italic>Turkestanella</Emphasis> Repina, 1975

A replacement name, Irakimaspis nom. nov., is proposed for the mid-Cambrian redlichiide trilobite Turkestanella Repina, 1975. The name was preoccupied by the tentaculite Turkestanella Klishevich, 1969 (Dacrioconarida).     

Arbuscular mycorrhizal symbiosis regulates the physiological responses,ion distribution and relevant gene expression to trigger salt stress tolerance in pistachio

Mycorrhizal symbiosis is generally considered effective in ameliorating plant tolerance to abiotic stress by altering gene expression, and evaluation of genes involved in ion homeostasis and nutrient uptake. This study aimed to use arbuscular mycorrhizal fungus (AMF) to alleviate salinity stress and analyse relevant gene expression in pistachio plants under No/NaCl stress in greenhouse conditions. Arbuscular mycorrhizal symbiosis was used to study the physiological responses, ion distribution and relevant gene expression in pistachio plants under salinity stress. After four months of symbiosis, mycorrhizal root colonization showed a significant reduction in all tested parameters under salt stress treatment compared to non-saline treatment. Salinity affected the morphological traits, and decreased the nutrient content including N, P, Mg and Fe as well as K/Na and Ca/Na ratios, relative water content (RWC), membrane stability index (MSI), and increased the concentration of K, Ca and Na nutrient, glycine betaine, ROS and MDA. Inoculation of seedlings with AMF mitigated the negative effects of salinity on plant growth as indicated by increasing the root colonization, morphological traits, glycine betaine, RWC and MSI. Specifically, under salinity stress, shoot and root dry weight, P and Fe nutrient content, K/Na and Ca/Na ratio of AMF plants were increased by 53.2, 48.6, 71.6, 60.2, 87.5, and 80.1% respectively, in contrast to those of the NMF plants. The contents of Na, O^2•− and MDA in AMF plants were significantly decreased by 66.8, 36.8, and 23.1%, respectively at 250 mM NaCl. Moreover, salinity markedly increased SOS1, CCX2 and SKOR genes expression and the inoculation with AMF modulated these genes expression; however, NRT2.4, PHO1 and PIP2.4 gene expressions were increased by salinity and AMF. It could be concluded that inoculation of AMF with Rhizophagus irregularis conferred a larger endurance towards soil salinity in pistachio plants and stimulate the nutrient uptake and ionic homeostasis maintenance, superior RWC and osmoprotection, toxic ion partitioning, maintaining membrane integrity and the ion-relevant genes expression.     

Chronic stress and its effects on adrenal cortex apoptosis in pregnant rats

The model of chronic intermittent stress by immobilization during pregnancy may produce alterations in the mechanisms that maintain adrenal gland homeostasis. In earlier investigations using this model, significant variations in plasma prolactin and corticosterone levels, and adrenal gland weights were observed. We hypothesized that chronic stress causes changes in apoptosis in the adrenal glands of pregnant rats. We identified and quantified apoptotic cells in the adrenal cortex and examined their ultrastructural characteristics using transmission electron microscopy. Adrenal glands of pregnant rats at gestation days 12, 17 and 21 were studied for control and experimental (stressed) rats. Immunolabelling techniques, stereological analysis and image quantification of adrenal gland sections were combined to determine differences in apoptosis in the different cell populations of the adrenal cortex. The apoptotic index of the experimental rats showed a significant reduction at gestation day 17, while at days 12 and 21 there were no differences from controls. Moreover, the apoptotic index of the reticular zones in control and experimental animals showed a significant increase compared to the glomerular and fascicular zones at the three gestation times studied. Chronic stress by immobilization reduced the caspase-dependent apoptotic index at gestation day 17, which may be related to variations in plasma concentrations of estrogens and prolactin.     

Adjustment of juvenile tuatara to a cooler,southern climate: operative temperatures,emergence behaviour and growth rate

Translocations for conservation often involve species limited to relict distributions. However, uncertainty can exist regarding the ability of source individuals to acclimatise following a shift to a distant location. We investigated the ability of captive-reared juvenile tuatara (Sphenodon punctatus) of Cook Strait stock (41°S) to adjust to outdoor, predator-protected pens within Orokonui Ecosanctuary (45 °S). We examined potential basking and within burrow temperatures, the influence of temperature on emergence, and growth rates in comparison with other locations. Tuatara at Orokonui reached their preferred temperature when basking over summer, and burrows provided protection from freezing over winter. Emergence was temperature-dependent and essentially ceased during winter. Growth rates of Orokonui-held juveniles were within the range for four other captive-rearing facilities and faster than for wild juveniles from a Cook Strait population. As all Orokonui-held juveniles have survived and grown we conclude that the climate at this southern location is suitable to consider a free-release.     

Biosynthesis of GA73 Methyl Ester in Lygodium Ferns

Biosynthesis of GA73 methyl ester (GA73-Me), the principal antheridiogen in Lygodium ferns, was investigated. From the methanol extract of prothallia of Lygodium circinnatum, GA25, GA73, GA73-Me, GA88-Me, and a few unknown GA73 derivatives were detected by GC-MS. Because the presence of GA25 suggests that GA24, a direct precursor of GA25, could also be present in L. circinnatum prothallia, we used feeding experiments to investigate the possibility that GA24 is a precursor of GA73-Me. In L. circinnatum prothallia, [2H2]GA24 was converted into [2H2]GA73-Me and a trace amount of [2H2]GA9-Me, whereas [2H3]GA9 was converted into [2H3]GA9-Me and [2H3]monohydroxy-GA9-Me. Because GA73-Me, GA9-Me, and their monohydroxy derivatives had been identified by GC-MS from the culture medium of L. circinnatum prothallia, our results suggest that GA73-Me is biosynthesized from GA24 via GA73, and that neither GA9 nor GA9-Me is a precursor of GA73-Me. Though the possibility had been suggested that GA73-Me is biosynthesized from 9,15-cyclo-GA9 (GA103), [2H2]GA103 was not converted into [2H2]GA73-Me.