Radial variation of vessel size and distribution in cork oak wood (<Emphasis Type="Italic">Quercus suber</Emphasis> L.)

Quercus suber L. is an important species producing cork whose wood characteristics have not been investigated a lot. Cork oak wood vessels are a striking feature and the most abundant wood tissue largely influencing density and permeability. Vessel size and distribution were studied in approximately 40 year-old and never debarked cork oaks by continuously measuring along the radial direction in the transverse section of wood discs taken at 1.3 m of height using image analysis techniques. The vessel size increases with age from 7660 ± 2286 to 21136 ± 6119 μm², the conductive area from 5.4 ± 2.2 to 11.6 ± 3.9%, and the vessel density remains approximately constant between 5.2 ± 1.5 and 7.3 ± 3.5 vessels/mm². In comparison with ring-porous and some evergreen oaks, cork oaks show a similar conductive area but smaller vessels. Vessel architecture is known to play an important role on oaks tolerance to hydric stress, and these cork oak trees were growing under very harsh edaphoclimatic conditions, not tolerated by other oaks. The well-developed and deep root system allowing access to constant water supply may contribute to the cork oak’s relatively high conductive area.     

Seropositivity and risk factors for Brucella in dairy cows in urban and peri-urban small-scale farming in Tajikistan

In this cross-sectional study, we assessed and mapped the seroprevalence of brucellosis in small-scale dairy farming in an urban and peri-urban area of Tajikistan and investigated factors associated with seropositivity. As urban and peri-urban farming is both an opportunity to improve the livelihood for small-scale farmers and a potential public health hazard, studies are warranted to reveal possible peculiarities in the epidemiology of brucellosis in this type of dairy farming. In total, 904 cows of breeding age belonging to 443 herds in 32 villages were serologically tested with indirect enzyme-linked immunosorbent assay (ELISA) and positive samples confirmed with competitive ELISA. Two logistic regression models were used to investigate an association between seropositivity and risk factors at herd and individual level. The herd and individual seroprevalences were 4.1 and 2.0 %, respectively. Herds with a history of abortions were found to be associated with seropositivity [odds ratio (OR)?=?5.3; 95 % confidence interval (CI), 1.3–21.3]. Large herds with more than eight cattle were more likely to be seropositive compared to smaller herds with one to two cattle (OR?=?13.9; 95 % CI, 1.6–119). The number of calves produced per cow (indicating age) was found to be associated with seropositivity. Younger cows with one to two produced calves were less likely to be seropositive compared to older cows with more than six produced calves (OR?=?0.24; 95 % CI, 0.06–1.0). Neither introduction of new cattle to the herd nor communal grazing was associated with seropositivity. This study shows that infection with Brucella (1) is present in small-scale urban and peri-urban dairy farming in Tajikistan and (2) has significant negative effects on reproductive performance in this farming system and (3) that some previously known risk factors for seropositivity in rural farming system were absent here.     

Circumferential variation of heartwood and stem quality in maritime pine stems

Maritime pine (Pinus pinaster Ait.) is an important timber and pulpwood species covering about 4 million ha in Portugal, Spain and France. This work studied the cross-sectional distribution of heartwood and sapwood along the stem using 3D modelling on 20 trees. The target was to assess the potential of this species for the industrial production of heartwood sawn products. The maritime pine stems were characterized by wide sapwood of 10 cm, in average, and the presence of heartwood at all height levels with constant diameter up to 35 % tree height, decreasing afterwards. In the radial section, the heartwood follows a circumferential-like shape which changes along the stem. Pith eccentricity index values were low and homogeneous regarding to stem and higher for heartwood. Heartwood cross-sectional shape was constant up to 45 % of total height of the tree and more elongated upwards. The constant heartwood diameter, low taper and pith eccentricity index, and an approximate circular shape up to 10 m height indicated these species’ potential to produce solid wood products made out of heartwood.     

Effects of α-lipoic and ascorbic acid on the muscle and brain fatty acids and antioxidant profile of the South American pacu Piaractus mesopotamicus

The effects of dietary α-lipoic acid (LA) and vitamin C on the fatty acid (FA) composition in the brain and muscle and vitamins E and C levels in the brain were studied in the fish Piaractus mesopotamicus. A two-factorial design, where diets were devoid or supplemented with ascorbate (500 mg AA kg^− 1) and/or lipoic acid (1000 mg kg^− 1), was used. The levels of eicosapentaenoic acid (20:5n − 3, EPA) increased (P < 0.01) in muscle polar lipids (PL) in LA groups (6.93% ± 0.43 vs. 5.83% ± 0.40 and 6.68% ± 0.53 vs. 6.00% ± 0.39), and the same trend was also seen in the brain, however not significant. These changes are suggested to be caused by a change in lipid metabolism rather than being a direct effect of protection by LA against lipid peroxidation. No interaction of vitamin C and LA neither effects of LA on vitamin E (15.1-19.2 mg α-tocopherol g^− 1 tissue) or vitamin C (total AA, 41.7-89.8 μg g^− 1 tissue) in brain was detected.     

Spray-drying Microencapsulation of an Extract from Tilia tomentosa Moench Flowers: Physicochemical Characterization and in Vitro Intestinal Activity

Plant Foods for Human Nutrition - Silver linden (Tilia tomentosa Moench, TtM) flowers possess several health-promoting properties, especially at the neurological level, such as intestinal...     

Methanolic extract of Verbascum macrurum as a source of natural preservatives against oxidative rancidity

The antioxidant properties of various fractions of a methanolic extract obtained from the aerial parts of Verbascum macrurum have been determined by monitoring their capacity to scavenge the stable free-radical DPPH. They were also evaluated as natural preservatives against oxidative rancidity using the accelerated Rancimat method. Their activities expressed as protection factor (PF(r)) indicated that the fractions rich with phenylpropanoid glycosides were more potent compared to alpha-tocopherol and of the same magnitude as BHT, which were used as reference standards. Ten natural compounds were identified as components of this methanolic extract and were isolated by medium-pressure liquid chromatography (MPLC). Assessment of their antioxidant activities established that acteoside, a polyhydroxylated phenylpropanoid glycoside derivative, is the most potent free radical scavenger and showed the highest protection factor (PF(r)) against sunflower-oil-induced oxidative rancidity. Its activity is comparable to the synthetic antioxidant BHT and clearly superior to natural alpha-tocopherol. This compound therefore represents a very interesting candidate for use in food preservation as natural protecting agent against oxidative rancidity.     

Passive and Active Sampling of Benzene in Different Urban Environments in Gothenburg, Sweden

Urban benzene concentration and personal exposure to benzene were measured within different urban environments in Gothenburg, Sweden. Three intensive monitoring campaigns were carried out in May 2000, February 2001 and May 2001. Three different environments were selected; two central built-up areas with different traffic densities (high and low) and one large urban park. The methods used included passive and active sampling. Passive sampling was used to retrieve spatial variability in urban benzene concentrations, while active sampling aimed to give data on personal exposure levels within the designated areas. The passive sampling showed large spatial and temporal variations in urban benzene concentrations. The benzene concentrations, ranging from 1.0 to 3.1 μg m^?3, were typically two to four times higher within the high-traffic built-up area compared to the adjacent urban park. This was mainly due to the proximity to motorised traffic. A comparison between personal exposure and active stationary measurements showed that the personal exposure levels were roughly 1.5 times higher in the heavy traffic area and 1.3 times higher in the light traffic area than the fixed benzene concentrations. The personal exposure levels in the park were equal to the active stationary benzene concentration. Given the large spatial heterogeneity within urban areas, the placement of single street level point measurements becomes crucial. Care must be taken to ensure that the measurements are actually representative when using these measurements to estimate urban concentrations and exposure levels.     

Management Zones Classified With Respect to Drought and Waterlogging

Within-field variations in potential grain yield may be due to variations in plant available soil water. Different water holding capacities affect yield differently in different years depending on weather. By estimating plant-water availability in different weathers, scenarios could be created of how yield potential and thereby fertilizer demand may vary within fields. To test this, measured cereal grain yields from a dry, a wet and an intermediate year were compared with different soil moisture related variables in a Swedish arable field consisting of clayey and sandy areas. Soil water budget calculations based on weather data and maximum plant available water (PAW), estimated from soil type and rooting data, were used to assess drought. A reasonable correlation between estimated and measured soil moisture was achieved. In the dry year, drought days explained differences in yield between the clayey and the sandy soil, but yield was better explained directly by maximum PAW, elevation, clay content and soil electrical conductivity (SEC). Yield correlated significantly with SEC and elevation within the sandy soil in the dry year and within the clayey soil in the wet year, probably due to water and nitrogen limitation respectively. Dense SEC, elevation and yield data were therefore used to divide the field into management zones representing different risk levels for drought and waterlogging. These could be used as a decision support tool for site-specific N fertilization, since both drought and waterlogging affect N fertilization demand.