The effect of temperature on sensory quality,chemical composition and growth of carrots (Daucus carota L.). III. Different diurnal temperature amplitudes

Summary

Data from experiments with carrots grown in phytotrons under different day and night temperatures at two locations in Norway and three harvesting dates were treated by means of Principal Component Analysis (PCA). No effect of the single temperature amplitudes were found, the significant main effects were due to the mean temperature levels of 12 and 188C, location and harvest date. The PCA visualized the effect of mean temperature level on sensory, chemical and physical variables. Differences between the two groups were mainly caused by variation in sensory variables, the first group being characterized by high score for whiteness, sweetness, acidic taste, crispness, juiciness, glucose, fructose and root length. The other group had a high score for colour, odour, overall taste and flavour parameters, firmness, dry matter, sucrose, a and b-carotene, root weight and root diameters.     

Concentrations of plasma luteinising hormone,prolactin, progesterone and androgens during the ovulatory cycle of the Turkey

1. Changes in the concentrations of plasma luteinising hormone (LH), prolactin, androgen and progesterone were measured during the ovulatory cycle of the turkey.

2. Single pre‐ovulatory peaks of plasma LH, androgen and progesterone were observed which took 8, 8 and 12 h respectively, to increase and return to base‐line values. The concentration of plasma prolactin tended to be elevated between 6 h before and 6 h after the LH peak with the maximum values occurring after the peak.

3. The changes in the concentrations of plasma LH and progesterone were 3‐ and 7‐fold respectively while 2‐fold changes were observed in the concentrations of plasma androgen and prolactin.

4. The pre‐ovulatory concentration of plasma progesterone and prolactin began to decrease 4 and 6 h respectively, after the pre‐ovulatory peak of LH.

5. Ovulation and oviposition occurred 6 to 8 h and 36.10+ 0.57 h (SEM) ( n= 11) respectively after the pre‐ovulatory peak of LH.

6. In birds kept on 14 h light/d, pre‐ovulatory peaks of LH were initiated only during a 10 to 11‐h period starting within 2 h after the onset of darkness.

7. A comparison between these data and those from the fowl suggest that the egg is retained in the turkey's oviduct for about 3 to 4 h longer than in the fowl.     

Genetic analysis on body weight at different ages in broiler chicken raised in commercial environment

A multivariate model was developed and used to estimate genetic parameters of body weight (BW) at 1–6 weeks of age of broilers raised in a commercial environment. The development of model was based on the predictive ability of breeding values evaluated from a cross-validation procedure that relied on half-sib correlation. The multivariate model accounted for heterogeneous variances between sexes through standardization applied to male and female BWs differently. It was found that the direct additive genetic, permanent environmental maternal and residual variances for BW increased drastically as broilers aged. The drastic increase in variances over weeks of age was mainly due to scaling effects. The ratio of the permanent environmental maternal variance to phenotypic variance decreased gradually with increasing age. Heritability of BW traits ranged from 0.28 to 0.33 at different weeks of age. The direct genetic effects on consecutive weekly BWs had high genetic correlations (0.85–0.99), but the genetic correlations between early and late BWs were low (0.32–0.57). The difference in variance components between sexes increased with increasing age. In conclusion, the permanent environmental maternal effect on broiler chicken BW decreased with increasing age from weeks 1 to 6. Potential bias of the model that considered identical variances for sexes could be reduced when heterogeneous variances between sexes are accounted for in the model.     

Preliminary report on oral treatment against salmon lice,Lepeophtheirus salmonis,with Neguvon

Neguvon (Bayer) was administered orally as a therapeutic against the parasitic copepod Lepeophtheirus salmonis. An effective dose is stated and the concentration remaining in fish muscle was measured.     

Moderate nitrogen retention in temperate heath ecosystem after elevated CO2, drought and warming through 7 years

Nitrogen (N) dynamic is one of the main controlling factors of responses to climate change in N-limited terrestrial ecosystems, which rely on nutrient recycling and retention. In this study we investigate the N partitioning in ecosystem compartments of a grassland heath, and the impact of multiple climate change factors on long-term N retention after ¹⁵N pulse labelling. The impacts of elevated carbon dioxide (eCO₂), warming and drought and the treatments in combination on ecosystem N retention were investigated in a field scale manipulation experiment. A 6-year time-course was assessed by pulse-labelling with the stable N isotope ¹⁵N and by sampling after 1 day, 1 year and 6 years. After 6 years we observed that the total ecosystem retained 42% of the amended ¹⁵N across treatments (recovery of the amended ¹⁵N in the pool). The fate of the applied ¹⁵N was mainly stabilization in soil, with 36% ¹⁵N recovery in soil, while the plant compartment and microbial biomass each retained only 1%–2% of the added ¹⁵N. This suggests a moderate retention of N, for all treatments, as compared to similar long-term studies of forest ecosystems. A decreased ammonium and vegetation N pool combined with higher ¹⁵N retention in the soil under eCO₂ treatments suggests that eCO₂ promoted processes that immobilize N in soil, while warming counteracted this when combined with eCO₂. Drought treatments contrastingly increased the vegetation N pool. We conclude that as the organic soil layer has the main capacity for N storage in a temperate heathland-grassland, it is important for buffering nutrient availability and maintaining a resilient ecosystem. However, the full treatment combination of drought, warming and eCO₂ did not differ in ¹⁵N recovery from the control, suggesting unchanged long-term consequences of climate change on retention of pulse added N in this ecosystem.     

Toxocara spp. infections in paratenic hosts

The zoonotic roundworms Toxocara canis and T. cati are not only present worldwide in their definitive hosts; they also frequently occur in other animal species, including humans. In those so-called paratenic hosts, the larvae do not develop into the adult stage, but rather migrate throughout the somatic tissue and persist as infectious L3 stage for extensive periods. Those arrested larvae may lead to severe inflammatory reactions and consequently to a wide range of pathological and clinical manifestations. However, the infected paratenic hosts also constitute a potential source of infection for the definitive hosts or humans who may also function as paratenic hosts. In the present review, current knowledge of larval migration in a variety of possible paratenic hosts is summarized including variations of migration routes and susceptibilities. Furthermore, information about the clinical and pathological changes for the presented species and possible consequences of the somatic migration of larvae, i.e. the resulting tissue damage as well as adverse host reactions to arrested larvae are reviewed. There are still many questions unanswered regarding larval behaviour in hosts other than their definitive host. Therefore, it is of great importance to continue further elaboration on the biology of Toxocara spp. to prevent further spreading of larvae in both the paratenic and the definitive host.     

The environmental impacts of the production of hemp and flax textile yarn

This study aimed to quantify major environmental impacts associated with the production of hemp yarn using Life Cycle Analysis (LCA). A reference scenario of traditional hemp warm water retting was compared to: (1) bio-retting, i.e. hemp green scutching followed by water retting, (2) babyhemp, based on stand retting of pre-mature hemp, (3) dew retting of flax. Overall, neither of the alternative scenarios was unambiguously better than the reference. The impacts of the hemp reference scenario and the flax scenario were similar, except for pesticide use (higher for flax) and water use during processing (higher for hemp). Bio-retting had higher impacts than the reference scenario for climate change and energy use, due to higher energy input in fibre processing. Babyhemp had higher impacts than the reference scenario for eutrophication, land occupation and pesticide use. A reduction of the environmental impacts of hemp yarn should give priority to reduction of energy use in the fibre processing and yarn production stages and to reduction of eutrophication in the crop production phase.     

Swine influenza viruses isolated in 1983, 2002 and 2009 in Sweden exemplify different lineages

Swine influenza virus isolates originating from outbreaks in Sweden from 1983, 2002 and 2009 were subjected to nucleotide sequencing and phylogenetic analysis. The aim of the studies was to obtain an overview on their potential relatedness as well as to provide data for broader scale studies on swine influenza epidemiology. Nonetheless, analyzing archive isolates is justified by the efforts directed to the comprehension of the appearance of pandemic H1N1 influenza virus. Interestingly, this study illustrates the evolution of swine influenza viruses in Europe, because the earliest isolate belonged to ''classical'' swine H1N1, the subsequent ones to Eurasian ''avian-like'' swine H1N1 and reassortant ''avian-like'' swine H1N2 lineages, respectively. The latter two showed close genetic relatedness regarding their PB2, HA, NP, and NS genes, suggesting common ancestry. The study substantiates the importance of molecular surveillance for swine influenza viruses.     

Long-term decline and local extinction of Clethrionomys rufocanus in boreal Sweden

Over the past three decades in boreal Sweden, there has been a long-term decline of cyclic sympatric voles, leading to local extinctions of the most affected species, the grey-sided vole (Clethrionomys rufocanus). We monitored this decline by snap-trapping on 58 permanent plots spread over 100 km² in spring and fall from fall 1971–2003. The reason for the decline is largely unknown, although a common major factor is likely to be involved in the decline of C. rufocanus and of the coexisting voles. However, here we deal with the reasonability of one complementary hypothesis, the habitat fragmentation hypothesis, which assumes that part of the decline of C. rufocanus is caused by habitat (forest) destruction. There was considerable local variation in the decline among the 58 1-ha sampling plots, with respect to both density and timing of the decline; however, all declines ended up with local extinction almost without exception. Local declines were not associated with habitat destruction by clear-cutting within sampling-plots, as declines started about equally often before as after clear-cutting, which suggested that habitat destruction outside sampling plots could be involved. In a multiple regression analysis, local habitat preference (LHP; expressed as a ratio of observed to expected number of voles trapped per habitat) together with two habitat variables in the surrounding (2.5×2.5 km²) landscape matrix explained 56% of the variation among local cumulated densities of C. rufocanus and hence of local time-series. LHP was positively correlated and explained 31% of the variation, while connectivity among clear-cuts was negatively correlated and proximity among xeric-mesic mires was positively correlated and explained additional 16% and 9%, respectively. Even if the overall decline cannot be connected to local clear-cutting on sampling-plots, clear-cutting and hence habitat fragmentation/destruction in the surrounding landscapes potentially influenced grey-sided vole numbers negatively.     

Regional assessment of the temporal trends in soil acidification in Southern Sweden,using the safe model

The dynamic soil acidification model SAFE was applied to 44 forested sites in Skåne, southern Sweden, using available Swedish databases on present soil status, vegetation and deposition. Time series of deposition were derived for each site from present deposition in a generalized fashion by dividing deposition into different classes and scaling with deposition trends from the literature. This study connects the current status of the soil and the soil development with critical load maps calculated with the steady-state model PROFILE.The model was calibrated against measurements of present base saturation from the Swedish Forest Inventory. Model output was compared with available measurements of soil water chemistry.