Harvesting of logging residues affects diameter growth and pine weevil attacks on Norway spruce seedlings

Removal of logging residues causes significant nutrient losses from the harvesting site. Furthermore, collection of residues into piles could lead to small-scale differences in establishment conditions for seedlings. We studied the effects of stem-only (SOH) and aboveground whole-tree harvesting (WTH) on Norway spruce (Picea abies) seedling growth and pine weevil (Hylobius abietis) damage at two sites (SE and W Norway). We also compared two planting environments within the WTH plots (WTH-0: areas with no residues, WTH-1: areas where residue piles had been placed and removed before planting). In practice, one-third of the residues were left on site after WTH. After three growing seasons there were no differences for height or diameter increment between SOH and WTH (WTH-1 and WTH-0 combined) treatments. However, relative diameter increment was largest for WTH-1 seedlings and lowest for WTH-0 seedlings. Few seedlings sustained pine weevil attacks at the W Norway site, with no differences among treatments. At the SE Norway site, the percent of seedlings damaged by pine weevils and average debarked area were significantly higher after WTH (82% and 3.3?cm²) compared to SOH (62% and 1.7?cm²). We conclude that WTH may lead to spatial differences in establishment conditions.     

Chemical changes in wheat pan bread during storage and how it affects the sensory perception of aroma,flavour, and taste

Wheat bread and whole wheat bread were stored for up to 3 weeks and specific chemical reactions were related to perceptual flavour changes as analysed by sensory profiling. Volatile and non-volatile compounds were quantified using GC–MS and HPLC. Results were examined by multivariate data analysis.     

Inhibition of lactoperoxidase-catalyzed 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and tyrosine oxidation by tyrosine-containing random amino acid copolymers

Oxidation of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) by lactoperoxidase was found to be inhibited by tyrosine-containing random amino acid copolymers but not by tyrosine. Both electrostatic effects and polymer size were found to be important by comparison of negatively and positively charged copolymers of varying lengths, with poly(Glu, Tyr)4:1 ([E 4Y 1] approximately 40) as the strongest competitive inhibitor (EC 50 approximately 20 nM). This polymer did not form dityrosine in the presence of lactoperoxidase (LPO) and peroxide. Furthermore, incubation with tert-butyl hydroperoxide, as opposed to hydrogen peroxide, resulted in a peculiar long lag phase of the reaction between the redox intermediate compound II and [E 4Y 1] approximately 40, indicating a very tight association between enzyme and inhibitor. We propose that interactions between multiple positively charged areas on the surface of LPO and the polymer are required for optimal inhibition.     

Daidzein as an antioxidant of lipid: effects of the microenvironment in relation to chemical structure

Isoflavone daidzein (D, pK a1 = 7.47 +/- 0.02 and pK a2 = 9.65 +/- 0.07) was, through a study of the parent compound and its three methyl anisol derivatives 7-methyldaidzein (7-Me-D, pK a = 9.89 +/- 0.05), 4'-methyldaidzein (4'-Me-D, pK a = 7.43 +/- 0.03), and 7,4'-dimethyldaidzein (7,4'-diMe-D), found to retard lipid oxidation in liposomal membranes through two mechanisms: (i) radical scavenging for which the 4'-OH was more effective than the 7-OH group in agreement with the oxidation potentials: 0.69 V for 4'-OH and 0.92 V for 7-OH versus Ag/AgCl in acidic solution and 0.44 V for 4'-O(-) and 0.49 V for 7-O(-) in alkaline solution and (ii) change in membrane fluidity through incorporation of the isoflavones, in effect hampering radical mobility. The radical scavenging efficiency measured by the rate of the reaction with the ABTS(*)(+) in aqueous solution followed the order D > 7-Me-D > 4'-Me-D > 7,4'-diMe-D, as also found for antioxidant efficiency in liposomes when oxidation was initiated with the water-soluble AAPH radical and monitored as the formation of conjugate dienes. For oxidation initiated by the lipid-soluble AMVN radical, the antioxidant efficiency was ranked as 4'-Me-D > D > 7,4'-diMe-D > 7-Me-D, and change in fluorescence anisotropy of fluorescent probes bound to the membrane surface or inside the lipid bilayer confirmed the effects of isoflavones on the membrane fluidity, especially for 7,4'-diMe-D.     

Quantification of infiltration processes in urban areas by accounting for spatial parameter variability

Background, Aims, and Scope  As a consequence of human living and activity, water infiltration to the urban subsurface occurs from a variety of different sources, like precipitation, irrigation, leaking pipes and sewers, septic tanks and rainwater infiltration ponds. This infiltration is strongly related with quality issues of the infiltrated water and further impact on groundwater quality. In order to set up an integrated urban water balance it becomes essential to estimate the infiltration processes, i.e. water flow and solute transport, from these different infiltration sources and to take into account the large spatial variability of sediment properties, the geometric settings of these sources and the groundwater table. For that purpose, the development of simple, physically-based quantification approaches is required in order to establish an efficiently working prediction and risk analysis tool within the framework of an integrated urban water management system. The scope of the presented work was to demonstrate the applicability of the developed approaches at urban scale. Methods  Since a detailed, three-dimensional, numerical quantification of the infiltration processes within the entire urban area is not possible, the individual sources were considered as independent within the EU AISUWRS project. Different models were developed for balancing infiltration from areal and point sources with respect to the related flow pattern. The analytical model UL_FLOW, based on one-dimensional, steady state analytical solutions, allows the estimation of conservative tracer residence times in layered sediments under varying infiltration rates. The numerical model WSTM, based on a three-dimensional random walk approach, calculates water and solute transport from pipe leaks. Additionally, the sources were classified in accordance to the spatial distribution of the parameters determining the infiltration processes. Results  UL_FLOW was applied to data sets from the city of Rastatt within a case study of the AISUWRS project. Each neighbourhood of water balance computation by the Urban Volume and Quality Model (UVQ) was defined as an areal infiltration source with unique parameter values for sediment depth, profile and properties, as well as infiltration rate time series. Groundwater recharge and residence time series were computed for each neighbourhood. Relevant statistical parameters obtained by time series analyses from those time series could be mapped by GIS. Point infiltration, particularly from sewers, was classified due to the sediment parameters and the distance to the groundwater table at each source location in order to reduce computational efforts. WSTM computations provided time series of groundwater recharge and tracer breakthrough for some specific cases. Discussion  The analytical model UL_FLOW provides fast and efficient computation of groundwater recharge and residence times accounting for storage effects within the unsaturated zone of urban areas. The reliability of this model has been shown by cross validation with HYDRUS1D. Because of the high computational effort, WSTM could provide only short-term simulations for some specific parameter sets for which residence time estimates could be derived. Conclusions  UL_FLOW provides an analytical modelling tool for balancing one-dimensional areal infiltration and estimating residence times under varying conditions including spatial parameter variability. These balances could be used for assessing the impact of those infiltration sources on groundwater quality. The tracer breakthrough from point infiltration sources computed by WSTM could also be used for such kinds of assessment. The larger spatial parameter variability associated with these sources could be handled by classification in GIS environments. Recommendations and Perspectives  Similar to the areal sources, a simple balance approach for point sources based on analytical solutions needs to be developed for estimating residence times in order to avoid large computational efforts. Such a model would complete the balancing of all kinds of infiltration sources in urban areas efficiently. Since the approaches are based on the balance of the physical processes, they have a large predictive capability and could be included into an integrated urban water balance and management system. The mapping of the statistical values of the residence times provides a tool to compare parts of the urban areas and to visualize differences between urban water management scenarios.     

Analysis of genetic diversity in a sweet potato (Ipomoea batatas L.) germplasm collection from Tanzania as revealed by AFLP

Sweet potato (Ipomoea batatas L.) is the fifth most important crop in the developing countries after rice, wheat, maize and cassava. The amplified fragment length polymorphism (AFLP) method was used to study the genetic diversity and relationships of sweet potato accessions in the germplasm collection of Sokoine University of Agriculture, Morogoro and Sugarcane Research Institute, Kibaha, Tanzania. AFLP analysis of 97 sweet potato accessions using ten primer combinations gave a total of 202 clear polymorphic bands. Each one of the 97 sweet potato accessions could be distinguished based on these primer combinations. Estimates of genetic similarities were obtained by the Dice coefficient, and a final dendrogram was constructed with the un-weight pair-group method using arithmetic average. AFLP-based genetic similarity varied from 0.388 to 0.941, with a mean of 0.709. Cluster analysis using genetic similarity divided the accessions into two main groups suggesting that there are genetic relationships among the accessions. Principal Coordinate analysis confirmed the pattern of the cluster analysis. Analysis of molecular variance revealed greater variation within regions (96.19%) than among regions (3.81%). The results from the AFLP analysis revealed a relatively low genetic diversity among the germplasm accessions and the genetic distances between regions were low. A maximally diverse subset of 13 accessions capturing 97% of the molecular markers diversity was identified. We were able to detect duplicates accessions in the germplasm collection using the highly polymorphic markers obtained by AFLP, which were found to be an efficient tool to characterize the genetic diversity and relationships of sweet potato accessions in the germplasm collection in Tanzania.     

Effects of size grading on growth and survival of juvenile turbot at two temperatures

Juvenile turbot were size graded into three size groups (mean initial size): Small (3.4 g), medium (7.0 g) and large (10.5 g), and additional fish were held in ungraded (6.6 g) groups. Subgroups (n = 396) of fish were tagged and individual growth rates and social interactions within different size categories were studied in fish reared at 13 and 19 °C. Size grading of juvenile turbot did not improve growth. Specific growth rates (SGR) were mainly size-related, and no differences in SGR or mortality between the experimental groups at both tem-peratures were found. A higher level of social interactions was indicated amongst medium-sized fish than amongst those in the smallest and largest categories. Excess feeding may have been important factors in reducing aggression, so that the growth of the smallest individuals was not suppressed by the larger individuals in the present study. Grading seems to be an unnecessary operation to improve the growth and survival of juvenile turbot (5- 150 g). However, as it was mainly the smallest individuals in each group that died, grading of very small turbot (2-5 g) can be recommended.     

焦磷酸测序鉴别猪线粒体细胞色素b基因单倍型

为了鉴别猪线粒体细胞色素 b(cytochrom e B,cyt b)基因单倍型 ,选择 9个不同品种共 4 15头猪作为试验材料 ,采用实时 DNA测序新方法焦磷酸测序 ,分析了 cyt b单核苷酸多态性 (single nucleotide polymorphism s,SNPs)。分析结果显示 3种不同单倍型 E、A1和 A2。除 1头临高猪属于单倍型 A2外 ,其他 6个中国地方品种猪均属于单倍型A1;瑞典长白猪和大白猪存在单倍型 E和 A1,而皮特兰猪存在单倍型 E和 A2。此外 ,基于焦磷酸测序 ,在通城猪中发现了 1个新的 SNP位点。     

A long term study of the health status and performance of sows on different feed allowances during late pregnancy. I. Clinical observations, with special reference to agalactia post partum

Thirty nine pairs of full sibs were investigated over 6 parities in a long term study on the effects of late pregnancy feed allowance on the occurrence of agalactia post partum and on the performance of sows and piglets. A careful examination of all sows with a rectal temperature exceeding 39.5 degrees C was performed by a veterinarian within the first 48 h after farrowing. Milk-samples were taken from sows with elevated rectal temperatures and showing clinical symptoms of agalactia. During the last 15 days of gestation the sows in the control group were fed 3.4 kg daily and the sows in the experimental group 1.0 kg daily of a commercial type of diet. In 26.6% of the farrowings in the control group the sows were agalactic whereas the corresponding figure in the experimental group was 14.4%. On clinical examination udder changes were observed in a majority of the diseased sows in both groups. However, the agalactic sows in the control group were generally more affected, with lower water and feed consumption than in the experimental group. No effects of age of the sow (parity number) or length of the gestation period on the incidence of agalactia were demonstrated. The rectal temperature of agalactic sows was significantly higher than in the healthy sows already 1 day before farrowing. The agalactic sows farrowed a larger number of stillborn piglets, which indicates an early establishment of the disease. The number of weaned piglets at 6 weeks did not differ between agalactic and healthy animals. The interval from weaning to first oestrus was not influenced by agalactia in the preceding lactation.     

Incidence of positive heartworm antibody and antigen tests at IDEXX Laboratories: trends and potential impact on feline heartworm awareness and prevention

Data from the IDEXX Laboratories Reference Laboratory Network were retrospectively examined for feline heartworm testing trends in testing frequency, geographic bias, and prevalence for the years 2000--2006. Examination of the data supports the commonly held view that veterinarians do not embrace heartworm disease testing or prevention in cats to the same degree they do in dogs. Despite significant awareness and adoption of heartworm testing and prevention in dogs, we hypothesized that heartworm testing rates are lower for cats than for dogs despite a significant prevalence of feline infection. This is important because a perceived low rate of infection in cats is likely to manifest in a low adoption of testing and prevention. In reality, the overall feline heartworm antigen-positive rate is significant--on average 0.9% over the period studied--and in some regions was estimated to be as high as 4.6%. This compares with an average canine heartworm prevalence rate of 1.2%, a feline leukemia virus prevalence of 1.9%, and a feline immunodeficiency prevalence of 1.0%. Based on the low rate of testing and these prevalence rates, practitioners are routinely missing cases of adult feline heartworm infections and the recently defined heartworm-associated respiratory disease (H.A.R.D). Increased antigen testing would result in detection of a significant number of positive cases. In addition, this population of infected cats would represent the "tip of the iceberg" relative to the greater number of cats that have early infection or are at risk for infection.