Babesia bovis and B. bigemina: Persistence of infection in friesian cows following vaccination with live antibabesial vaccines

The persistence of Babesia bovis and B. bigemina infection in Friesian cows, following vaccination with attenuated live vaccines, was assessed by subinoculation of blood into splenectomized calves. Subinoculation tests showed that B. bigemina persisted in two out of 20 cows vaccinated 10 and 46 months previously, and that B. bovis persisted in 11 out of 22 cows vaccinated 10 to 47 months previously. Antibody was detected in five B. bigemina - and 15B. bovis -vaccinated cows. Parasites of both species persisted among the serologically negative cows, whereas blood obtained from serologically positive cows failed to transmit infection. It is concluded that in the absence of reinfection Friesian cattle may spontaneously eliminate B. bigemina and B. bovis infection after various periods following vaccination.     

From trees to fleas: masting indirectly affects flea abundance on a rodent host

Mast seeding causes strong fluctuations in populations of forest animals. Thus, this phenomenon can be used as a natural experiment to examine how variation in host abundance affects parasite loads. We investigated fleas infesting yellow-necked mice in beech forest after 2 mast and 2 non-mast years. We tested 2 mutually exclusive scenarios: (1) as predicted by classical models of density-dependent transmission, an increase in host density will cause an increase in ectoparasite abundance (defined as the number of parasites per host), versus (2) an increase in host density will cause a decline in flea abundance (“dilution,” which is thought to occur when parasite population growth is slower than that of the host). In addition, we assessed whether masting alters the relationship between host traits (sex and body mass) and flea abundance. We found a hump-shaped relationship between host and flea abundance. Thus, the most basic predictions are too simple to describe ectoparasite dynamics in this system. In addition, masting modified seasonal dynamics of flea abundance, but did not affect the relationship between host traits and flea abundance (individuals with the highest body mass hosted the most fleas; after controlling for body mass, parasite abundance did not vary between sexes). Our results demonstrate that pulses of tree reproduction can indirectly, through changes in host densities, drive patterns of ectoparasite infestation.     

持续水流刺激对青鱼幼鱼体型特征的影响

为了考察持续水流刺激对青鱼幼鱼体型特征的影响,在(25±0.5)℃水温条件下,将大小相当的144尾体质量为(11.90±0.24)g、体长为(8.94±0.31)cm的实验鱼随机分为对照组、9cm/s、18cm/s和36cm/s处理组,分别在不同水流速度下处理8周.随后从各组中各随机挑选12尾实验鱼,测量分析其体型特征参数变化.结果显示:9cm/s处理组的头长和头长/体长显著大于对照组(p0.05);18cm/s处理组的头长、头高、体高、叉长、鱼体侧面积和头长/体长显著大于对照组(p0.05);36cm/s处理组的头长、头高、尾柄下侧长度、尾柄侧面积、头长/体长和尾柄侧面积/鱼体侧面积显著大于对照组(p0.05),其他形态参数较对照组无显著差异.结果表明:持续水流刺激显著影响了青鱼幼鱼的体型特征;高流速(36cm/s)刺激下青鱼幼鱼的尾柄面积显著增加,这可能有利于其游泳能力的改善.     

Automated methods for determination of fat and moisture in meat and poultry products: collaborative study

A collaborative study was conducted to compare automated methods for rapid determination of fat and moisture in meat and poultry products with the official AOAC solvent extraction and forced-air oven methods, respectively. Fourteen products were tested, with fat and moisture contents ranging from 2 to 43% and 44 to 74%, respectively. Eight of the collaborating laboratories analyzed the products by using a moisture/fat analyzer; 4 laboratories used the AOAC methods. Standard deviations for within-laboratory repeatability, between-laboratory reproducibility, and bias for each product indicated that the rapid methods were acceptable. The moisture/fat analyzer methods have been adopted official first action for fat and moisture analyses in meat and poultry products.     

Paraoxonase (PON) 1, 2 and 3 Expression in Granulosa Cells and PON1 Activity in Follicular Fluid of Dairy Cows

Normal metabolic activity in ovarian follicles may result in oxidative stress and damage to oocytes. The aim of this study was to evaluate expression of the natural anti‐oxidants paraoxonase (PON) 1, 2 and 3 in granulosa cells and PON1 activity in follicular fluid (FF) and plasma of dairy cows. For the first experiment, ovaries were collected from cows at slaughter, after which follicles were dissected and classified as oestrogen active (EAF) or atretic (ATF). Expression of PON1, PON2 and PON3 mRNA was evaluated in granulosa cells, and activity of PON1 was measured in FF. PON1 mRNA was undetectable in granulosa cells, PON2 mRNA expression was not different between follicle types, and PON3 mRNA tended to be higher in EAF (p = 0.11). The activity of PON1 in FF was higher (p = 0.01) for EAF (82.6 ± 8.0 kU/L) than ATF (53.9 ± 6.8 kU/L), as were high‐density lipoproteins (HDL), low‐density lipoproteins (LDL) and total cholesterol concentrations. In the second experiment, we aimed to compare plasma and FF PON1 activity in early lactation Holstein cows (n = 15) with pre‐ovulatory EAF. Activity of PON1 was twofold higher (p < 0.0001) in plasma (122.5 ± 11.1 kU/L) than in FF (61.4 ± 5.2 kU/L). Plasma concentrations were also higher (p < 0.0001) for HDL, LDL and total cholesterol when compared to FF. In conclusion, FF concentrations of PON1, HDL, LDL and total cholesterol were higher in healthy oestrogen active bovine follicles than in atretic follicles. PON1 was not expressed by granulosa cells indicating that high PON1 activity in bovine FF is apparently derived by transfer from blood in association with HDL.     

The effects of frozen storage conditions on lycopene stability in watermelon tissue

The purpose of this investigation was to evaluate the rate of deterioration of lycopene in watermelon tissue during frozen storage, because little is known about the stability of watermelon tissue lycopene under cold storage conditions. Heart tissue from each of nine individual watermelons was stored at -20 or -80 degrees C as either small chunks or puree and periodically sampled over a year's time. Initial freeze-thaw experiments indicated that a small percentage of lycopene, approximately 4-6%, degraded during an initial freeze-thaw. Analyses of the samples showed a loss of approximately 30-40% lycopene over a year's storage at -20 degrees C and a loss of approximately 5-10% over the same period at -80 degrees C. Lycopene was slightly more stable in pureed compared with diced watermelon tissue at -20 degrees C, but not at -80 degrees C. The kinetic data were best fitted by application of two simultaneous, first-order decay processes. HPLC analysis of the samples after a year's storage suggested that beta-carotene was more stable during storage at -20 degrees C than was lycopene.     

Global analysis of the protection status of the world’s forests

This study presents a global analysis of forest cover and forest protection. An updated Global Forest Map (using MODIS2005) provided a current assessment of forest cover within 20 natural forest types. This map was overlaid onto WWF realms and ecoregions to gain additional biogeographic information on forest distribution. Using the 2008 World Database on Protected Areas, percentage forest cover protection was calculated globally, within forest types, realms and ecoregions, and within selected areas of global conservation importance. At the 10% tree cover threshold, global forest cover was 39 million km². Of this, 7.7% fell within protected areas under IUCN management categories I–IV. With the inclusion of IUCN categories V and VI, the level of global forest protection increased to 13.5%. Percentage forest protection (IUCN I–IV) varied greatly between realms from 5.5% (Palearctic) to 13.4% (Australasia), and for forest types from 3.2% (temperate freshwater swamp forest) to 28% (temperate broadleaf evergreen forest). Median protection of forest cover in 670 ecoregions (forest above a specified threshold) was 5.9% (IUCN I–IV); at IUCN I–VI, 46% of the ecoregions had less than 10% forest protection. Considering their biodiversity importance, forest protection within global priority areas was insufficient, e.g., median protection of 8.4% in biodiversity hotspots (IUCN I–IV). Results have policy relevance in terms of the target of the Convention on Biological Diversity (CBD), reconfirmed in 2008, to effectively conserve “at least 10% of each of the world’s forest types”. Regular updates of these analyses would allow progress towards achieving that target to be monitored.