沙棘油脂

果实 沙棘果实由果肉（68%）、种子（23%）和果皮（7.75%）组成（Zadernowski et al.,1997）.Yang和Kallio（2001）最近发现,从中国、芬兰和前苏联（FSU）等地大量选择后采集的沙棘果实中23%～28%是种子,72%～77%是柔软的果肉/果皮.沙棘果实可提取3种油：种子油、果肉油和果皮油.不同于其他植物,沙棘果实的各部分都能合成并积累脂肪.有时果肉油和果皮油没有区别,因此统称为果实油或果肉油.沙棘叶也含油,这部分内容将在稍后部分进一步说明.     

Comparison of radiographic osteoarthritis scores in dogs less than 24 months or greater than 24 months following tibial plateau leveling osteotomy

Radiographic osteoarthritis scores were determined in 60 dogs up to 3 years following tibial plateau leveling osteotomy. Radiographs taken immediately following surgery and at long-term follow-up 1 to 3 years later were evaluated by 2 certified radiologists using a modified 32-point osteoarthritis scale. Changes in osteoarthritis scores were evaluated by paired t-tests and regression analysis. Sub-groups of dogs were formed to evaluate if osteoarthritis scores changed differently for follow-up periods of < 24 months compared with those > 24 months. There was a significant increase in osteoarthritis score from post-operative to follow-up evaluations for all dogs studied. Regression analysis of the relationship of months after surgery to change in osteoarthritis score was not significant. These results indicate that osteoarthritis did progress following tibial plateau leveling osteotomy, but not in a linear fashion over time.     

Longitudinal data collection of Mycobacterium avium subspecies Paratuberculosis infections in dairy herds: the value of precise field data

Longitudinal infection data on Mycobacterium avium subspecies paratuberculosis (MAP) was collected on three dairy farms in Northeastern United States during approximately 10 years. Precise data on animal characteristics and animal location within farm were collected on these farms. Cows were followed over time with regard to MAP status during biannual fecal and serum sampling and quarterly serum sampling. Approximately 13 000 serum samples, 6500 fecal samples and 2000 tissue samples were collected during these years. Prevalence of positive samples was 1.4% for serological samples, 2.2% in fecal samples and 16.7% in tissue samples. Infection dynamics of MAP was studied and resulted in a number of potential changes in our understanding of MAP infection dynamics. First, a high prevalence of MAP infection was observed in these herds due to lifetime follow up of cows, including slaughter. Second, two distinctly different infection patterns were observed, so called non-progressors and progressors. Non-progressors were characterized by intermittent and low shedding of MAP bacteria and a virtual absence of a humoral immune response. Progressors were characterized by continuous and progressive shedding and a clearly detectable and progressive humoral immune response. Strain typing of MAP isolates on the three farms identified on two of three farms a dominant strain type, indicating that some strains are more successful in terms of transmission and infection progression. Continuous high quality longitudinal data collection turned out to be an essential tool in our understanding of pathobiology and epidemiology of MAP infections in dairy herds.     

Yields of cultured Pacific oysters Crassostrea gigas Thunberg improved after one generation of selection

Parental families (G₀) in three lines of Pacific oysters were selected based on live weight and meat yields at harvest. The average live weight yield of progeny (G₁) from crossing G₀-selected lines in seven trials was 9.5% greater than that of nonselected control families and live weight yields were significantly greater (ANOVA, P<0.001) in four out of seven trials. The response to selection was greater if G₁ families were tested at the same site as their parents' selection site rather than at a different site, although this effect was only significant for G₁ families of cohort 5 (P<0.01) but not cohort 7 (P>0.05). A significant genotype×environment interaction affected yields in both cohort 5 and cohort 7 (ANOVA; P<0.001). In addition, correlation between the yields of the same families planted at both intertidal and subtidal sites was positive but weak (cohort 5, r=0.30; cohort 7, r=0.35), indicating that selection for high yield in one environment would likely result in a low correlated response in a different environment. Nonetheless, it was possible to identify six families in cohort 5 and four families in cohort 7 that were among the top 10 families at both sites. Further evaluation of families across a wider range of environments is needed to determine if it is possible to substantially improve yields by selecting “generalist” families that perform well along the whole Pacific coast, or whether it will be necessary to select lines that are suited to particular sites.     

Big impacts from small abstractions: The effects of surface water abstraction on freshwater fish assemblages

1. Abstractions and diversions are prevalent in river networks worldwide; however, specific mechanisms and measures reflecting changes in functional characteristics of aquatic assemblages in response to flow abstraction have not been well established. In particular, the influence of small takes on fish assemblages is poorly understood.
2. Field surveys and stable‐isotope analyses were used to evaluate the impact of differing levels of flow abstraction on fish assemblage structure, and native–non‐native patterns of coexistence, associated with small surface water abstractions in four streams in New Zealand. Study design accounted for longitudinal processes (spatial autocorrelation) to isolate the effects of abstractions on fish assemblages.
3. Reaches with reduced flows downstream of abstraction points had significantly lower fish abundances per metre of stream length, probably because of decreased habitat size, altered interspecific interactions and barriers to movement. The loss of larger fish in reaches with high abstraction resulted in shallower mass–abundance slopes and shorter stable isotope‐derived food‐chain lengths, likely to have been caused by fewer trophic links in the food web. The large fish absent from these reaches were flow‐sensitive introduced salmonids, resulting in higher relative abundances of small‐bodied native fish, probably as a result of predatory and competitive release.
4. Quantification of metrics designed to characterize ecosystem functioning as well as abundance and species composition indicated that small water abstractions can alter both the structure and composition of stream fish assemblages and modify the outcomes of native–non‐native species interactions. Thus, a better understanding of the effects of small abstractions could be used to improve the strategic management of fish in invaded riverscapes.

     

Can Batesian mimicry help plants to deter herbivores?

Several authors have suggested that edible plants could avoid herbivory by mimicking olfactory cues of toxic plants. However, very few studies have been carried out to test this hypothesis. The aims of the present study were to identify the volatiles of three clover species and to test whether a species lacking chemical defences, such as red clover, could avoid being grazed by rabbits by mimicking the volatiles of the cyanogenic white clover. Two main volatiles were identified in all three clover species, and a further two volatiles were present in white clover only. Rabbits presented with a choice between white clover, red clover and red clover sprayed with white clover extract ate significantly more red clover than white or white-flavoured red clover. The results suggest that the volatiles of toxic plants could be used and exploited as a source of natural, safe and effective repellents to control the impact of pest herbivores on plants.     

Predator control for protecting kaki (Himantopus novaezelandiae)—lessons from 20 years of management

In New Zealand, the endemic kaki or black stilt (Himantopus novaezelandiae) has been the focus of intensive conservation management for the past 20 years. Threatened by predation and habitat loss, the population fell to as low as 23 birds before management was implemented to reverse the decline. Predator trapping has been one form of management intervention in the wild, yet despite 20 years of control, there is only limited evidence to suggest that predator trapping is beneficial for the survival of kaki. Lack of adequate experimental design and understanding of the predator-prey dynamics in the system in which kaki live appear to be the main reasons why the benefits of predator control are not consistently clear. An adaptive management approach would have provided more information on the efficacy of predator trapping and increased understanding of the inter-relationships between kaki survival and predator abundance.     

Sea-level solar radiation in the biologically active spectrum

Calculations show a significant depletion of ultraviolet and visible radiation due to absorption and scattering by particulates and cloud drops for a fixed amount of ozone.