The fibrillar orientation in the S2-layer of wood fibres as determined by X-ray diffraction analysis

Summary It is the fibrillar orientation in the S2-layer which to a great extent determines the mechanical properties of the wood fibre, with regard both to strength and stiffness and to swelling properties. Measurements of the average fibril angle of fibres are not however easy and the results differ between the methods used. In order to evaluate in more detail how the fibril angle varies in spruce wood, an X-ray method based on diffraction from the 040-plane was developed. By comparison with microscopic examination it is concluded that reliable results relating to the fibrillar orientation in the S2-layer are obtained with the X-ray technique. It is shown that the fibril angle of mature wood is rather constant with regard to both age of the annual ring and its position in the height of the tree. The fibril angle of the earlywood is found to be only slightly higher than that of latewood fibres. It is also shown that compression wood may be easily identified by virtue of the fact that its fibril angle is much higher than that of normal mature wood.The authors thank Ms Ulla Jonsson for the microscopic measurements and Dr Anthony Bristow for the linguistic revision     

Ascorbic acid, carotenoids, and visual quality of baby spinach as affected by shade netting and postharvest storage

Baby spinach ( Spinacia oleracea L.) was grown under three types of shade netting (high transmittance, spectrum-altering, and low transmittance) to study the effect on the concentrations of vitamin C (ascorbic acid and dehydroascorbic acid), carotenoids, and chlorophyll and on the visual quality of the leaves. The spinach was sown in April and August and harvested at two growth stages. After harvest, leaves were stored in polypropylene bags at 2 and 10 degrees C. Shading significantly decreased the ascorbic acid concentration of April-sown spinach by 12-33%, but in the August-sown spinach, the response was inconsistent. Concentrations of total carotenoids and total chlorophylls were significantly higher under the nettings in many cases, especially under the spectrum-altering and low-transmittance nettings. Postharvest visual quality and postharvest persistence of the compounds analyzed were not greatly affected by shading. We conclude that these shade nettings are acceptable to use in baby spinach production when it comes to the studied aspects of internal and external quality of the produce.     

Large heterogeneity of the obesity epidemic in Danish adults

OBJECTIVE: To examine to what extent the obesity epidemic is a general phenomenon in adults by assessing the secular change, by birth cohort and age, in the prevalence of obesity and median body mass index (BMI) in Danish men and women measured between 1964 and 1994. DESIGN: Multiple cross-sectional population surveys. SETTING: The greater Copenhagen area of Denmark. SUBJECTS: The study included 17,065 men (30 336 observations) and 13,417 women (24,065 observations), aged 20-84 years. MAIN OUTCOME MEASURES: Trends in median BMI and prevalence of obesity estimated from measured height and weight in 10-year age groups. RESULTS: In general the prevalence of obesity was increasing, although in an irregular way: among men in two phases, during the 1970s and 1990s and among women only during the 1990s. Great heterogeneity was observed between birth cohorts and age groups. There was only little indication of an increasing trend in obesity prevalence for women, except for the 55-64-year-olds. In men, the prevalence of obesity was increasing in all age groups except in the youngest ones, and it was statistically significant only for men aged 35-74 years. There was no significant linear change in median BMI in any group, except for an increasing trend among men aged 50 years and above. CONCLUSION: Although the overall Danish trend for obesity prevalence, similar to trends world-wide, showed a marked increase, the trend was very heterogeneous and generally neither uniform nor significantly positive; the changes were irregular, different among men and women, and different in the different age and birth cohorts. The obesity problem in middle-aged and older men of certain birth cohorts poses a specific public health challenge. Future studies of determinants behind the heterogeneity in the development of the obesity epidemic may provide clues to its causes.     

Adaptability of birch (Betula pendula Roth) and aspen (Populus tremula L.) genotypes to different soil moisture conditions

For northern Europe’s climate, models predict an increase in periods of drought and waterlogging. Knowledge of variation between genotypes of Betula pendula (birch) and Populus tremula (aspen) to drought and excess soil moisture are unavailable but relevant for future development of forest ecosystems. We studied variation between genotypes to soil moisture in birch and aspen with plant material representing naturally regenerated populations and showed differences in acclimation to soil moisture conditions. Genotypes showing most growth and biomass accumulation across treatments maintained most leaf area, high gas exchange and water-use efficiency and grew most root mass but had the lowest root length per unit root dry mass compared to other genotypes. This indicates that these genotypes are more efficient in harvesting water from the soil under adverse conditions. We also showed that birch and aspen employ different strategies to cope with soil moisture conditions, with aspen investing more in perennial parts, while birch efficiently maintains foliar processes. When the expression of some known drought responsive genes was measured, only ACC oxidase was induced by the drought treatment at the beginning of the experiment, while surprisingly LEA5, RD22 and ADH1 did not respond to drought, but were up-regulated in prolonged wet conditions indicating oxidative stress and hypoxia and that these genes are responding to multiple stress factors. We conclude that in plants micro-propagated from naturally regenerated birch and aspen populations, there is variation between genotypes in acclimation efficiency to soil moisture conditions.     

Precipitation or water capacity indices? An analysis of the benefits of alternative underlyings for index insurance

Eastern Germany is often hit by drought causing income risk for crop farmers. Index-based risk management instruments could help crop farmers to reduce their farm income risk. Such instruments have some important advantages over damage-based insurance, like e.g. less moral hazard and adverse selection. At the same time they typically have a high level of basis risk. Up to now, mainly precipitation-based weather derivatives have been discussed as an appropriate risk management instrument for farmers in Germany. As a potentially more effective alternative, we propose water capacity-based index insurance. In order to show the benefits of a precipitation-based and water capacity-based index insurance, several contract designs are compared. Using a whole farm risk program planning approach, we show that for an average agricultural producer in Eastern Germany water capacity-based index insurance offers greater benefits than precipitation-based index insurance.     

ADAMTS17 mutation associated with primary lens luxation is widespread among breeds

Primary lens luxation (PLL) is a well-recognized, painful and potentially blinding inherited ocular condition in dogs. We screened PLL-affected dogs of 30 different breeds, to identify those which carried a previously described c.1473+1 G>A mutation in ADAMTS17 that is associated with PLL in Miniature Bull terriers, Lancashire Heelers, and Jack Russell terriers. This ADAMTS17 mutation was identified in PLL-affected dogs from 14 additional breeds. PLL-affected dogs from some breeds (most notably the Shar pei and the Brittany spaniel) did not carry the G1473+1A ADAMTS17 mutation, indicating they must suffer from a genetically distinct form of the condition. We also estimated the frequency of this ADAMTS17 mutation in some of the breeds. Our findings indicate the mutation segregates in a large number of different breeds of dog, many of which are terriers or breeds with terrier co-ancestry, but some of which have more diverse origins. Our results also indicate that the mutation is present at high frequency within most of the breeds in which it segregates. In the miniature bull terrier breed estimates of mutation frequency ranged from 0.27 to 0.39, corresponding to 7.3-15.2% PLL-affected dogs in this breed. We also identified an increased risk of PLL associated with heterozygosity at ADAMTS17, suggesting that carriers carry a low risk of developing PLL.     

Total lipid extraction of homogenized and intact lean fish muscles using pressurized fluid extraction and batch extraction techniques

The reliability and efficiency of pressurized fluid extraction (PFE) technique for the extraction of total lipid content from cod and the effect of sample treatment on the extraction efficiency have been evaluated. The results were compared with two liquid-liquid extraction methods, traditional and modified methods according to Jensen. Optimum conditions were found to be with 2-propanol/n-hexane (65:35, v/v) as a first and n-hexane/diethyl ether (90:10, v/v) as a second solvent, 115 degrees C, and 10 min of static time. PFE extracts were cleaned up using the same procedure as in the methods according to Jensen. When total lipid yields obtained from homogenized cod muscle using PFE were compared yields obtained with original and modified Jensen methods, PFE gave significantly higher yields, approximately 10% higher (t test, P < 0.05). Infrared and NMR spectroscopy suggested that the additional material that inflates the gravimetric results is rather homogeneous and is primarily consists of phospholipid with headgroups of inositidic and/or glycosidic nature. The comparative study demonstrated that PFE is an alternative suitable technique to extract total lipid content from homogenized cod (lean fish) and herring (fat fish) muscle showing a precision comparable to that obtained with the traditional and modified Jensen methods. Despite the necessary cleanup step, PFE showed important advantages in the solvent consumption was cut by approximately 50% and automated extraction was possible.     

Antioxidants, low molecular weight carbohydrates, and total antioxidant capacity in strawberries (Fragaria x ananassa): effects of cultivar, ripening, and storage

Four cultivars of strawberries (Senga Sengana, BFr77111, Elsanta, and Honeoye) were studied for their content of antioxidants, total antioxidant capacity, and low molecular weight carbohydrates in relation to harvest year, ripening stage, and cold storage. For ascorbic acid, chlorogenic acid, ellagic acid, and total antioxidative capacity, measured in both water-soluble and water-insoluble extracts, there was a 2-5-fold variation among cultivars. Unripe berries contained lower concentrations of chlorogenic acid and p-coumaric acid and also quercetin and kaempferol compared with riper berries. During cold storage for up to 3 days, relatively few changes in the concentration of the different antioxidants occurred. The concentrations of several investigated parameters were interrelated, for example, for ascorbic acid and water-soluble antioxidant capacity and for ellagic acid and water-insoluble antioxidant capacity. The dominating sugars in strawberries were fructose and glucose, but considerable amounts of sucrose were also present, and their contents varied among cultivars, giving a predicted glycemic index of approximately 81. Verbascose, raffinose, and stachyose were found in only minor amounts. The study shows that the concentration of a number of bioactive compounds in strawberries varied according to cultivar, ripening stage, and storage. This information should make it possible to select strawberries with an optimal content of bioactive compounds.     

Wood ash fertilization alters the forest humus Archaea community

The combined and separate effects of Cd and wood ash on Archaea from coniferous forest humus were studied in a microcosm experiment. Nonmetric multidimensional scaling of the denaturing gradient gel analysis of polymerase chain reaction amplified 0.9 kb 16S ribosomal DNA fragments revealed changes in archaeal communities due to the ash treatments. Cd with or without ash did not further influence the result. Representatives of the ash and control communities were cloned, grouped by restriction fragment length polymorphism analysis and finally sequenced. All sequences belonged to non-thermophilic Crenarchaea.